WO2018024234A1

WO2018024234A1 - Power control method, device, inverter apparatus, and power station controller

Info

Publication number: WO2018024234A1
Application number: PCT/CN2017/095833
Authority: WO
Inventors: 戴志威
Original assignee: 中兴通讯股份有限公司
Priority date: 2016-08-03
Filing date: 2017-08-03
Publication date: 2018-02-08
Also published as: CN107689642A

Abstract

A power control method, a device, inverter apparatuses (10, 30), and power station controllers (60, 80). The method comprises: an inverter apparatus receives a control command containing a first parameter used to determine a reactive power compensation value to compensate for a reactive power of a photovoltaic power station system where the inverter apparatus is located, and/or a second parameter used to determine a harmonic compensation value to compensate for a harmonic of the photovoltaic power station system where the inverter apparatus is located (S202); the inverter apparatus determines, according to the first parameter, the reactive power compensation value to compensate for the reactive power of the photovoltaic power station system, and/or determines, according to the second parameter, the harmonic compensation value to compensate for the harmonic of the photovoltaic power station system (S204); and the inverter apparatus compensates, according to the determined reactive power compensation value, for the reactive power of the photovoltaic power station system, and/or compensates, according to the harmonic compensation value, for the harmonic of the photovoltaic power station system (S206).

Description

Power control method, device, inverter device and power station controller

Technical field

The present disclosure relates to the field of communications, and in particular to a power control method, apparatus, inverter device, and power plant controller.

Background technique

Most of the load on the power system is an inductive load, which reduces the power factor of the grid, resulting in a decrease in voltage quality, a shortened life of the equipment, and an increase in power investment. A reasonable solution is to increase the capacitance compensation cabinet (reactive compensation device) on the spot.

The harmonic problem of the power grid mainly comes from the widespread use of power electronic equipment, specifically two points: First, a large number of reactive power compensation devices are used to improve the power factor; second, power electronic changes are widely used to improve system reliability and efficiency. Streamer.

As the penetration depth of photovoltaic power generation in power systems increases, the problems of reactive power and harmonics become more and more serious. Therefore, on the one hand, in the process of building centralized and distributed PV power plants, it is necessary to increase the power quality monitoring and control system unit (including power quality monitoring, reactive power compensation equipment, active filtering device), which also means multiple quantities. The increase of power electronic converter equipment; on the other hand, to some extent, the photovoltaic inverter's own reactive power compensation capacity. According to the description of the State Grid Corporation's Technical Regulations for Connecting PV Power Grids, the power factor of large and medium-sized PV power plants should be continuously adjustable from 0.98 (leading) to 0.98 (lag).

Adopting the above scheme, the following problems exist: 1) The introduction of power quality monitoring and control system unit increases the investment cost and operation and maintenance cost of photovoltaic construction station; 2) The power electronic converter equipment is multiplied, and the power station and the power grid are not improved. Stability factor; 3) The reactive power compensation and filtering capability of the PV inverter has not been fully exploited, resulting in wasted capacity.

Therefore, in the related art, the problem of reactive power or harmonics is solved by increasing the power quality monitoring and management system unit to increase the investment cost and operation and maintenance cost of the photovoltaic station.

Summary of the invention

Embodiments of the present disclosure provide a power control method, apparatus, inverter device, and power station controller to at least solve the related art to increase reactive power or harmonic problems by increasing power quality monitoring and management system units. The problem of building investment costs and operation and maintenance costs.

According to an embodiment of the present disclosure, a power control method is provided, including: an inverter device receiving a control instruction, wherein the control instruction carries a photovoltaic power station system for determining that the inverter device pair is located a first parameter of the reactive power compensation amount of the reactive power to be compensated and/or a second parameter for determining a harmonic compensation amount for the inverter device to compensate for harmonics of the photovoltaic power plant system in which the inverter device is located; Determining, by the inverter device, a reactive power compensation amount for reactive power compensation of the photovoltaic power station system by the inverter device according to the first parameter; and/or determining, according to the second parameter, the The harmonic compensation amount of the harmonic compensation of the photovoltaic power station system by the inverter device; the inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and Or, the harmonics of the photovoltaic power station system are compensated according to the harmonic compensation amount.

Optionally, the inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and/or according to the harmonic compensation amount Compensating the harmonics of the photovoltaic power plant system includes: determining, in the case that the inverter device is in an operating state, the inverter device determines a preset state in which the inverter device is located, wherein the The preset state is a state in the predetermined state machine; the inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount and the preset state; And/or, according to the determined harmonic compensation amount, and the preset state, the harmonic of the photovoltaic power station system is compensated.

Optionally, the predetermined state machine includes: a first state, a first switching state, a second state, and a second switching state; wherein the first state is that the DC output power output by the inverter device is greater than zero The active power output is a preset value, and the reactive power compensation amount is a determined state in which the reactive power compensation amount and/or the harmonic compensation amount is the determined harmonic compensation amount; the first switching state is a transition state of the first state to the second state; the second state is a DC output power and an active power output of the inverter device is zero, and the reactive power compensation amount is the determined The power compensation amount and/or the harmonic compensation amount are the determined harmonic compensation amount The second switching state is a transition state in which the second state is switched to the first state; the first state, the first switching state, the second state, and the second switching state Cycle through the 24-hour cycle.

Optionally, the workflow of the predetermined state machine includes: if the preset state is the first state, the inverter device determines whether the inverter meets the first switching condition, where The first switching condition is that the DC parameter used to identify the DC output of the inverter device is less than a first preset threshold, and the duration of the DC parameter is greater than or equal to the first time threshold, or is used to identify the The DC parameter of the DC output of the inverter device is smaller than the first preset threshold, the duration of the DC parameter is greater than or equal to the first time threshold, and the synchronization time of the inverter device is located in the first preset threshold range. The DC parameter is at least one of the following: a DC input power, a DC input voltage, and a DC input current; if the result of the determination is that the inverter meets the first switching condition, the inverter will The operating state of the inverter is switched from the first state to a first switching state; in a case where the preset state is a first switching state, the inverter device is turned off Determining a DC input maximum power tracking function of the inverter device, adjusting a DC input voltage of the inverter device according to an open circuit voltage of the inverter device, and disconnecting a DC contactor of the inverter device, according to the a bus voltage regulation value that regulates a bus voltage of the inverter device; when the bus voltage voltage is regulated at a duration of the first bus voltage greater than or equal to a first switching time threshold, the inverter device The first switching state is switched to the second state; in a case where the preset state is the second state, the inverter device determines whether the inverter meets a second switching condition, where The second switching condition is that a DC parameter for identifying a DC output of the inverter device is greater than or equal to a second preset threshold, and a duration of the DC parameter is greater than or equal to a second time threshold, or Determining a DC parameter of the DC output of the inverter device is greater than or equal to a first preset threshold, where a duration of the DC parameter is greater than or equal to a second time threshold, and The synchronization time of the inverter device is within a second preset threshold range, and the DC parameter is at least one of: a DC input power, a DC input voltage, and a DC input current; and the determination result is that the inverter meets the In the case of the second switching condition, the inverter device switches the operating state of the inverter from the second state to the second switching state; the second state is the second state In the case of the switching state, the inverter device tracks the DC voltage of the inverter device by the bus voltage of the inverter device, and attracts the DC contactor of the inverter device to start the device. The DC input maximum power tracking function of the inverter device switches the second switching state to the first state.

Optionally, the receiving, by the inverter device, the control instruction comprises: communicating with a power station controller of the photovoltaic power station system by using a Modbus transmission control protocol/network protocol TCP/IP communication protocol or a power carrier PLC, and receiving the power station controller The control command sent.

According to still another embodiment of the present disclosure, a power control method is provided, including: acquiring state information of a point to be compensated in a photovoltaic power station system; determining, according to the acquired state information, and a preset allocation rule, a reactive power compensation component allocated by the inverter device for compensating the reactive power of the point to be compensated by the inverter device and/or for the inverter device to harmonize the point to be compensated The wave compensates the harmonic compensation component; the determined reactive compensation component and/or the harmonic compensation component is transmitted to the corresponding inverter device.

Optionally, determining, according to the acquired state information, and the preset allocation rule, the foregoing, for the inverter device, the The reactive power compensation component that compensates for the work power and/or the harmonic compensation component that is used by the inverter device to compensate the harmonic of the point to be compensated includes: according to each of the inverters a first remaining capacity of the device, and a second remaining capacity of all of the inverter devices in the photovoltaic power plant system, respectively determining a distribution coefficient of each of the inverter devices, wherein the first remaining capacity is a root mean square value of a power difference between the rated power of the inverter device and the output active power and the compensated reactive power, wherein the second remaining capacity is the first remaining capacity of all the inverter devices And determining, according to the determined distribution coefficient, and the total amount of reactive power to be compensated of the point to be compensated, respectively, the reactive compensation component allocated for each of the inverter devices; and/or, according to the determined The distribution coefficient to Harmonic of the total amount to be compensated point to be compensated, are determined as the allocation of each harmonic compensation component of the inverter device.

Optionally, in the process of transmitting the determined reactive compensation component and/or the harmonic compensation component to the corresponding inverter device, the method further includes: being used for the photovoltaic power station system The synchronization time of the time synchronization between the power station controller and each of the inverter devices is sent to the corresponding inverter device.

According to still another embodiment of the present disclosure, a power control apparatus is provided, including: a receiving module, configured to receive, by an inverter device, a control instruction, where the control instruction carries a pair for determining the inverter device The first parameter of the reactive power compensation amount for compensating the reactive power of the photovoltaic power plant system and/or the harmonic compensation for determining the harmonics of the photovoltaic power plant system in which the inverter device is located a second parameter of the quantity; the first determining module is configured to determine, according to the first parameter, a reactive power compensation amount that the inverter device performs reactive power compensation on the photovoltaic power station system according to the first parameter; And/or determining, according to the second parameter, a harmonic compensation amount of the inverter device for performing harmonic compensation on the photovoltaic power station system; and a compensation module configured to set the inverter device according to the determined The working power compensation amount compensates the reactive power of the photovoltaic power station system; and/or compensates the harmonics of the photovoltaic power station system according to the harmonic compensation amount.

Optionally, the compensation module includes: a first determining unit, configured to determine a preset state of the inverter device when the inverter device is in an operating state The preset state is a state in a predetermined state machine; a compensation unit configured to the inverter device according to the determined reactive power compensation amount, and the preset state, to the photovoltaic power station The reactive power of the system is compensated; and/or the harmonics of the photovoltaic power plant system are compensated according to the determined amount of harmonic compensation and the predetermined state.

Optionally, the receiving module includes: a receiving unit configured to communicate with a power plant controller of the photovoltaic power station system by using a Modbus transmission control protocol/network protocol TCP/IP communication protocol or a power carrier PLC, and receiving the power station controller The control command sent.

According to still another embodiment of the present disclosure, an inverter device is provided, the inverter device including any of the above devices.

According to still another embodiment of the present disclosure, there is provided a power control apparatus, comprising: an acquisition module configured to acquire state information of a point to be compensated in a photovoltaic power plant system; and a second determining module configured to be according to the acquired state Information, and preset allocation rules, respectively determined as each inverter Reactive power compensation component allocated by the device for compensating the reactive power of the point to be compensated by the inverter device and/or for the inverter device to perform harmonics of the point to be compensated The compensated harmonic compensation component; the transmitting module is configured to send the determined reactive compensation component and/or the harmonic compensation component to the corresponding inverter device.

Optionally, the second determining module includes: a second determining unit, configured to: according to a first remaining capacity of each of the inverter devices, and a second remaining of all inverter devices in the photovoltaic power station system a capacity, respectively determining a distribution coefficient of each of the inverter devices, wherein the first remaining capacity is a mean square of a squared difference between the rated power of the inverter device and the output active power and the compensated reactive power a root value, the second remaining capacity being a sum of the first remaining capacities of all the inverter devices; a third determining unit configured to determine the allocation coefficient according to the determination, and the absence of the point to be compensated The total amount of compensation to be compensated is determined as the reactive compensation component allocated to each of the inverter devices; and/or, according to the determined distribution coefficient, and the total amount of harmonic compensation to be compensated And determining the harmonic compensation component allocated for each of the inverter devices.

Optionally, the sending module is further configured to send a synchronization time of the power plant controller of the photovoltaic power station system and each of the inverter devices to a corresponding one of the inverter devices.

According to still another embodiment of the present disclosure, a power plant controller is provided, the power plant controller comprising the device of any of the above.

According to still another embodiment of the present disclosure, a storage medium is also provided. The storage medium includes a stored program, wherein the program is executed while performing the method of any of the above.

According to still another embodiment of the present disclosure, there is also provided a processor for running a program, wherein the program is executed to perform the method of any of the above.

Through the present disclosure, since the inverter device is used to compensate the reactive power of the photovoltaic power station system or the harmonics of the photovoltaic power station system according to the received control command, without additionally introducing reactive power compensation equipment and/or harmonic compensation equipment, Therefore, it is possible to solve the problem of reactive power or harmonics in the related art by increasing the power quality monitoring and management system unit. The problem of capital cost and operation and maintenance cost, so as to reduce the cost of building stations and operation and maintenance costs of photovoltaic power plants.

DRAWINGS

The drawings described herein are provided to provide a further understanding of the present disclosure, which is a part of the present disclosure, and the description of the present disclosure and the description thereof are not intended to limit the disclosure. In the drawing:

1 is a block diagram of a hardware structure of an inverter device of a power control method according to an embodiment of the present disclosure;

2 is a flowchart 1 of a power control method according to an embodiment of the present disclosure;

3 is a schematic structural diagram of a photovoltaic inverter device in accordance with a preferred embodiment of the present disclosure;

4 is a block diagram showing the structure of a photovoltaic inverter device operating state machine in accordance with a preferred embodiment of the present disclosure;

5 is a flowchart 1 of a power control method in accordance with a preferred embodiment of the present disclosure;

6 is a second block diagram of a hardware structure of a power plant controller of a power control method according to an embodiment of the present disclosure;

7 is a second flowchart of a power control method in accordance with an embodiment of the present disclosure;

8 is a schematic structural diagram of a power plant controller according to an embodiment of the present disclosure;

9 is a schematic structural diagram 1 of a photovoltaic power plant system according to an embodiment of the present disclosure;

10 is a second schematic diagram of a photovoltaic power plant system according to an embodiment of the present disclosure;

11 is a second flowchart of a power control method in accordance with a preferred embodiment of the present disclosure;

12 is a block diagram 1 of a power control apparatus according to an embodiment of the present disclosure;

FIG. 13 is a block diagram showing the structure of a compensation module 126 of a power control device according to an embodiment of the present disclosure;

FIG. 14 is a structural block diagram of a receiving module 132 of a power control device according to an embodiment of the present disclosure;

15 is a structural block diagram of an inverter device according to an embodiment of the present disclosure;

16 is a structural block diagram 2 of a power control device according to an embodiment of the present disclosure;

17 is a block diagram showing the structure of a second determining module 164 of a power control device according to an embodiment of the present disclosure;

18 is a structural block diagram of a plant controller in accordance with an embodiment of the present disclosure.

detailed description

The present disclosure will be described in detail below with reference to the drawings in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict.

It is to be understood that the terms "first", "second", and the like in the specification and claims of the present disclosure are used to distinguish similar objects, and are not necessarily used to describe a particular order or order.

Example 1

The method embodiment provided by Embodiment 1 of the present application can be executed in an inverter device or the like. Taking the operation on the inverter device as an example, FIG. 1 is a block diagram of a hardware structure of an inverter device of a power control method according to an embodiment of the present disclosure. As shown in FIG. 1, inverter device 10 may include one or more (only one shown) first processor 102 (first processor 102 may include, but is not limited to, a microprocessor MCU or a programmable logic device) A processing device such as an FPGA, a first memory 104 for storing data, and a first transmission device 106 for communication functions. It will be understood by those skilled in the art that the structure shown in FIG. 1 is merely illustrative and does not limit the structure of the above electronic device. For example, inverter device 10 may also include more or fewer components than those shown in FIG. 1, or have a different configuration than that shown in FIG.

The first memory 104 can be used to store software programs and modules of the application software, such as program instructions/modules corresponding to the power control method in the embodiment of the present disclosure, by the first processor 102 running the software program stored in the first memory 104 and The module, thus performing various functional applications and data processing, implements the above method. The first memory 104 can include a high speed random access memory, and can also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or His non-volatile solid-state memory. In some examples, the first memory 104 optionally includes memory remotely located relative to the first processor 102, which may be connected to the inverter device 10 over a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The first transmission device 106 is configured to receive or transmit data via a network. The network optional examples described above may include a wireless network provided by a communication provider of the inverter device 10. In one example, the first transmission device 106 includes a Network Interface Controller (NIC) that can be connected to other network devices through a base station to communicate with the Internet. In one example, the first transmission device 106 can be a Radio Frequency (RF) module for communicating with the Internet wirelessly.

In this embodiment, a power control method running on the inverter device is provided. FIG. 2 is a flowchart 1 of a power control method according to an embodiment of the present disclosure. As shown in FIG. 2, the process includes the following steps:

Step S202, the inverter device receives a control instruction, where the control instruction carries a first parameter and/or a reactive power compensation amount for determining that the inverter device compensates the reactive power of the photovoltaic power station system in which the inverter device is located. a second parameter for determining a harmonic compensation amount for the inverter device to compensate for harmonics of the photovoltaic power plant system in which it is located;

Step S204, the inverter device determines, according to the first parameter, a reactive power compensation amount for the reactive power compensation of the photovoltaic power station system by the inverter device; and/or, determining, according to the second parameter, the inverter device to perform the photovoltaic power station system Harmonic compensation amount of harmonic compensation;

Step S206, the inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and/or compensates the harmonics of the photovoltaic power station system according to the harmonic compensation amount.

Through the above steps, the inverter device is used to compensate the reactive power and/or harmonics of the photovoltaic power plant system according to the received control command, without additionally introducing reactive power compensation equipment and/or harmonic compensation equipment, and solving the related technology. Solving the problem of reactive power or harmonics by increasing the power quality monitoring and management system unit, there is a problem of increasing the investment cost and operation and maintenance cost of the PV station. The construction cost and operation and maintenance cost of the photovoltaic power station are low.

Optionally, in step S206, in a case that the inverter device is in an operating state, the inverter device may determine a preset state in which the inverter device is located, where the preset state is a predetermined state machine. The state of the inverter; the inverter device compensates the reactive power of the photovoltaic power plant system according to the determined reactive power compensation amount and the determined preset state; and/or, according to the determined harmonic compensation amount And the determined preset state to compensate for the harmonics of the photovoltaic power plant system in which it is located.

Through the above technical solutions of the embodiments of the present disclosure, the operating state of the inverter is refined by nesting a predetermined state machine in an operating state, thereby improving the accuracy of power control of the inverter device.

Optionally, the predetermined state machine may include multiple states, and the switching between the multiple states may be periodic or aperiodic. For the case of non-periodic switching, the state threshold may be set in advance, for example, according to an output state or an operating state of the inverter device, compared with a predetermined state threshold, and if the switching condition is satisfied, switching between states is performed. It is also possible to switch to the state corresponding to the switching instruction according to the corresponding switching instruction received by the power station controller or other control device. For the case of periodic switching, the inverter device can determine the switching between states according to the pre-configuration information (which may be determined by the pre-operation configuration or the control command sent by the plant controller or other control device). The period, and the time point at which the switching is made between different states, performs periodic switching between states. When switching between states, a corresponding transition state may also be included. When the inverter is in various states, the DC output power, active power, reactive power, etc. of the inverter can be set as needed.

Optionally, the predetermined state machine may include: a first state, a first switching state, a second state, and a second switching state; wherein, the first state is that the DC output power output by the inverter device is greater than zero, and the active power output is The preset value, the reactive power compensation amount is a state in which the determined reactive power compensation amount and/or the harmonic compensation amount is the determined harmonic compensation amount; the first switching state is a transition state in which the first state switches to the second state The second state is that the DC output power and the active power output of the inverter device are zero, and the reactive power compensation amount is determined by the determined reactive power compensation amount and/or the harmonic compensation amount is determined. The state of the harmonic compensation amount; the second switching state is a transition state in which the second state is switched to the first state; and the first state, the first switching state, the second state, and the second switching state are cyclically cycled in a 24-hour period.

With the above technical solution of the embodiment of the present disclosure, the inverter device performs the first state, the first switching state, the second state, and the second switching state in a 24-hour period, and realizes smooth switching of the state of the inverter device every day. The operation efficiency of the inverter device caused by the long-term in the same state is avoided, and the smooth switching between the states can be realized without stopping the operation, thereby ensuring the reliability of the operation of the inverter device.

Optionally, the workflow of the predetermined state machine may include:

When the preset state is the first state, the inverter device determines whether the inverter meets the first switching condition, where the first switching condition is that the DC parameter for identifying the DC output of the inverter device is smaller than the first The preset threshold, and the duration of the DC parameter is greater than or equal to the first time threshold, and the DC parameter may be one of DC input power, DC input voltage, DC input current, or two or three of them. combination. Optionally, the synchronization time of the inverter device may be used as an auxiliary condition for the handover determination, for example, determining whether the synchronization time of the inverter device is within a first preset threshold range (may also be greater than a certain time point). When the result of the determination is that the inverter satisfies the first switching condition, the inverter switches the operating state of the inverter from the first state to the first switching state.

When the preset state is the first switching state, the inverter device can turn off the DC input maximum power tracking function of the inverter device, according to the open circuit voltage of the inverter device (the photovoltaic device of the inverter device is open when the device is open) The voltage difference between the two ends of the negative pole) adjusts the DC input voltage of the inverter device (may adjust the DC input voltage of the inverter device to the open circuit voltage), and disconnects the DC contactor of the inverter device according to the first bus bar The voltage regulation value is used to regulate the bus voltage of the inverter device. When the bus voltage of the inverter device is regulated, the duration of the first bus voltage is greater than or equal to the first switching time threshold, the inverter device will be A switching state is switched to the second state.

In a case where the preset state is the second state, the inverter device determines whether the inverter device is full The second switching condition may be that the DC parameter used to identify the DC output of the inverter device is greater than or equal to a second preset threshold, and the DC parameter may be: DC input power, DC input voltage, DC. One of the input currents may also be a combination of two or three of them. Optionally, the synchronization time of the inverter device may be used as an auxiliary condition for the handover determination, for example, determining whether the synchronization time of the inverter device is within a second preset threshold range (may also be greater than a certain time point). In a case where the result of the determination is that the inverter satisfies the second switching condition, the inverter device switches the operating state of the inverter from the second state to the second switching state.

When the preset state is the second switching state, the inverter device tracks the DC voltage of the inverter device by the bus voltage of the inverter device, sucks the DC contactor of the inverter device, and starts the inverter. DC input maximum power tracking function of the device. After starting the DC input maximum power tracking function, the inverter device switches the second switching state to the first state.

With the above technical solution of the embodiment of the present disclosure, the inverter device performs the state switching after satisfying the condition by performing the judgment of whether the state is switched in the specific state, thereby realizing the intelligent switching between the different states, and improving the different states. The flexibility of switching.

Alternatively, the inverter device can receive control commands in a variety of ways, for example, a control command input by an administrator can be received through the interface. For example, a Modbus Transmission Control Protocol/Internet Protocol (TCP/IP) communication protocol or a Power Line Carrier (PLC) can be used to communicate with a power plant controller of a photovoltaic power plant system. The control command sent by the plant controller is received through a corresponding interface (physical interface or logical interface).

Through the above technical solution of the embodiment of the present disclosure, the inverter device communicates with the power station controller of the photovoltaic power station system by using the Modbus TCP/IP communication protocol or the PLC, and receives the control command, thereby realizing the inverter device by the power station controller. Unified control.

Based on the foregoing embodiment and the optional implementation manner, in order to explain the entire process interaction of the solution, in the preferred embodiment, a power control method is provided, which can be run in the inverter device, and can realize 24h all-weather reactive power. And harmonic compensation. It should be noted that, in the power control method, the inverter device is described by taking a photovoltaic inverter device as an example.

3 is a schematic structural diagram of a photovoltaic inverter device according to a preferred embodiment of the present disclosure. As shown in FIG. 3, the photovoltaic inverter device 30 includes a DC input terminal 302, a DC input control module 304, and a bus capacitor 306. The inverter bridge 308, the AC grid-connected control module 310, the inverter control module 312, and the monitoring module 314. At the same time, the photovoltaic inverter device 30 also includes components that are inconvenient to be illustrated in the drawings, including but not limited to: sampling circuits, driving circuits, and the like.

The inverter control module 312 obtains inverter state parameters through the sampling unit on one hand, including but not limited to: DC input voltage and current, DC contactor state, bus capacitance voltage, AC grid voltage and grid-connected current, AC contactor The state, the inverter bridge changes the switching temperature; on the other hand, the C communication unit (not shown) interacts with the S communication unit (not shown) of the monitoring module 314 to control parameters, including but not limited to: voltage threshold, Current threshold, temperature threshold, power threshold, power factor or reactive power compensation command, harmonic compensation command, function enable command, voltage and current, fault alarm. The C processing unit of the inverter control module 312 utilizes state parameters and control parameters to implement DC input maximum power tracking, bus voltage control, inverter grid-connected power generation, grid reactive power compensation, and grid harmonic compensation. Interactions include sending and receiving.

CAN communication or SCI serial communication is used between the C communication unit of the inverter control module 312 and the S communication unit of the monitoring module 314.

The monitoring module 314 exchanges control parameters with the C communication unit of the inverter control module 312 through the S communication unit, including but not limited to: voltage threshold, current threshold, temperature threshold, power threshold, power factor or reactive power compensation command. Harmonic compensation command, function enable command, voltage current, fault alarm; on the other hand, the S communication unit interacts with the power station controller D communication unit (not shown) in the following embodiments, including but It is not limited to: active power component, reactive power compensation component, and harmonic compensation component. The S processing unit of the monitoring module 314 uses the control parameters and scheduling parameters to implement functions such as fault alarm and reporting, power statistics, and human-computer interaction. Interactions include sending and receiving.

Modbus TCP/IP protocol communication is used between the S communication unit of the monitoring module 314 and the D communication unit of the power station controller.

There are many possible implementations for the photovoltaic inverter device 30.

The first possible implementation is that the hardware structure adopts the whole machine mode. The rated power of the whole machine is M kVA, among which the active power output capacity is M1kW, the reactive power compensation capacity is M2kvar, and the harmonic compensation capacity is M3kVA. Among them, it satisfies 0 ≤ M1 ≤ M, 0 ≤ M2 ≤ M, and 0 ≤ M3 ≤ M. The values of M, M1, M2 and M3 are selected according to the actual situation of the power station. At the same time, the values of M1, M2 and M3 can also be adjusted according to the preset rules of the plant controller during the operation of the power station.

The second possible implementation is that the hardware structure adopts a modular mode. The rated power of a single module is m kVA, the number of modules is N, N>1 and is an integer, m>0; the rated power of the inverter is N*m kVA.

For the second possible implementation manner, the first possible working mode is: the rated power of the whole machine is M kVA, wherein the active power output capacity of the inverter is N1*m kW, that is, the N1 modules realize the active power output; Reactive power compensation capacity N2*m kvar, that is, N2 modules realize reactive power compensation; harmonic compensation capacity N3*m kVA, that is, N3 modules realize harmonic compensation. Wherein, 0 ≤ N1 ≤ N, 0 ≤ N2 ≤ N, 0 ≤ N3 ≤ N and is an integer, and N = N1 + N2 + N3. The values of N, N1, N2, and N3 are selected according to the actual situation of the power station. At the same time, the values of N1, N2, and N3 can also be adjusted by the power station controller according to preset rules during power plant operation.

For the second possible implementation, the second possible working mode is: the rated power of the whole machine is M kVA, wherein the active power output capacity of the inverter is M1kW, the reactive power compensation capacity is M2kvar, and the filter compensation capacity is M3kVA; Module active power output capacity M1/N kW, reactive power compensation capacity M2/N kvar, harmonic compensation capacity M3/N kVA. Among them, it satisfies 0 ≤ M1 ≤ M, 0 ≤ M2 ≤ M, and 0 ≤ M3 ≤ M. The values of N, M1, M2, and M3 are selected according to the actual situation of the power station. At the same time, the values of M1, M2, and M3 can also be adjusted by the power station controller according to the preset rules during power plant operation.

A state machine is operated in the photovoltaic inverter device 30. As shown in FIG. 4, the operating state machine includes: a first state machine and a second state machine (acting similar to the aforementioned predetermined state machine). The two state machines are described below.

The first state machine includes a shutdown state 402, a standby state 404, an operational state 406, and a fault state 408.

Shutdown state 402: In the shutdown state 402, the photovoltaic inverter does not operate. Shutdown state 402 Can be converted to standby state 404. The condition that the shutdown state 402 is converted to the standby state 404 is that the monitoring module 314 of the photovoltaic inverter device 30 issues an instruction (power-on command) to the inverter control module 312, and the trigger mode includes manual or automatic, and the command is used for the photovoltaic inverse. The transformer device 30 transitions from the off state 402 to the standby state 404.

Standby state 404: A transition ready state between the inactive state and the operating state of the photovoltaic inverter device 30, the standby state 404 can be converted to a shutdown state 402, an operating state 406, and a fault state 408, respectively. The condition that the standby state 404 is switched to the shutdown state 402: the monitoring module 314 of the photovoltaic inverter device 30 issues an instruction (shutdown command) to the inverter control module 312, and the trigger mode includes manual or automatic, and the command is used for the photovoltaic inverter. The device 30 transitions from the standby state 404 to the shutdown state 402. The condition in which the standby state 404 transitions to the operating state 406: the photovoltaic inverter device 30 meets the operating conditions in the standby state 404. The condition in which the standby state 404 transitions to the fault state 408: the photovoltaic inverter device 30 detects a fault occurrence in the standby state 404.

The operating state 406: on the one hand, the photovoltaic inverter device 30 outputs the active power according to the maximum output capacity of the photovoltaic array (the night output is 0); on the other hand, according to the distribution issued by the monitoring module 314 of the photovoltaic inverter device 30 The power compensation component and each harmonic compensation component command output the reactive power and the harmonic compensation power to realize the power quality control at the power station level. The operational state 406 can be converted to a standby state 404 and a fault state 408. The condition that the operating state 406 is converted to the standby state 404: the monitoring module 314 of the photovoltaic inverter device 30 issues an instruction (eg, a shutdown command, a standby command, etc.) to the inverter control module 312, and the trigger mode includes manual or automatic. For a shutdown command, the command is used for the photovoltaic inverter device 30 to transition from the operational state 406 through the standby state 404 to the shutdown state 402. The condition in which the operating state 406 transitions to the fault state 408: the photovoltaic inverter device 30 detects a fault occurrence in the operating state 406.

Fault state 408: The fault alarm module (ie, the module in which the fault alarm occurs) stops working, and the non-faulty module works normally. The fault state 408 can be converted to a shutdown state 402 and a standby state 404. The condition that the fault state 408 is converted to the shutdown state 402: the system emergency shutdown command is issued. The condition that the fault state 408 transitions to the standby state 404: all fault alarms of the corresponding module are eliminated.

The second state machine is nested in the operating state 406 of the first state machine. Any of the second state machines It is possible that one state can jump out of the second state machine and enter the standby state 404 or the fault state 408 of the first state machine. The second state machine includes a Day state 410 (acting similar to the first state described above), a first switching state 412, a Night state 414 (the aforementioned second state is similar), and a second switching state 416. The working logic of the second state machine is as follows: Day state -> first switching state -> Night state -> second switching state -> Day state. The working state of the second state machine is related to time, 24h working around the clock, and a day and night alternate with a second state machine state rotation. Next, the states of the second state machine and the switching between the states will be described.

Day state 410: daytime state, daytime, the DC input power of the photovoltaic inverter device 30 is greater than 0, combined with the possible implementation of the photovoltaic inverter device 30 operating 24 hours a day, the inverter active power output P1kW, no The power compensation capacity Q1kvar, the filter compensation capacity F1kVA; the reactive power compensation amount and the harmonic compensation amount can be determined by the power plant controller in the following embodiment. The instructions issued by the power station controller may be sent to the inverter control module 312 via the monitoring module 314. The Day state 410 can be converted to a first switching state 412.

When the system satisfies the first switching condition, the second state machine transitions from the Day state 410 to the first switching state.

The first switching condition is established (satisfying the first switching condition) and there are many possible determination manners. The first possible determination manner is: the DC input power is less than the first input power threshold, and the duration is greater than or equal to the first time threshold, and the synchronization time can be used as an auxiliary condition to confirm that the current time is an evening period. The second possible determination manner is: the DC input voltage is less than the first input voltage threshold, and the duration is greater than or equal to the first time threshold, and the synchronization time can be used as an auxiliary condition to confirm that the current time is the evening period. The third possible determination manner is: the DC input current is smaller than the first input current threshold, and the duration is greater than or equal to the first time threshold, and the synchronization time can be used as an auxiliary condition to confirm that the current time is the evening period. The fourth possible way of determining is to use two or three combinations of the above three possible determination methods.

The first switching state 412: the photovoltaic inverter device 30 turns off the DC input maximum power tracking function, adjusts the DC input voltage to the open circuit voltage (the potential difference between the positive and negative terminals of the photovoltaic cell when the circuit is disconnected), and disconnects the DC contactor. The bus voltage is regulated to the first bus voltage regulation value. The first mentioned above Bus voltage regulation value, you can choose the maximum power point tracking (MPPT) operating voltage range upper limit. The first switching state 412 can be converted to a Night state 414. The condition that the first switching state 412 transitions to the Night state 414: the bus capacitance voltage is stabilized at the first bus voltage regulation value and the duration is greater than or equal to the second time threshold.

For the first switching state 412, the second state machine transitions from the first switching state 412 to the Night state 414 if the bus voltage is regulated to the first bus voltage regulation value and the duration is greater than or equal to the second time threshold.

Night state 414: night mode, at night, the DC contactor of the photovoltaic inverter device 30 remains disconnected, combined with the possible implementation of the photovoltaic inverter device 30 operating 24 hours a day, the inverter has an active power output of 0 kW. Reactive power compensation capacity Q2kvar, filter compensation capacity F2kVA; reactive power compensation amount and each harmonic compensation amount can be determined by the power plant controller in the following embodiment. The instructions issued by the power station controller may be sent to the inverter control module 312 via the monitoring module 314. The Night state 414 can be switched to the second switching state 416.

When the system satisfies the second switching condition, the second state machine is switched from the Night state 414 to the second switching state 416.

The foregoing second switching condition is established (satisfying the first switching condition) and there are many possible determination manners. For example, the DC input voltage is not less than the second DC input voltage threshold and the duration is greater than or equal to the second time threshold. The synchronization time can be used as an auxiliary condition to confirm that the current time is the morning time.

The second switching state 416: the photovoltaic inverter device 30 tracks the current DC input voltage value of the bus voltage, pulls in the DC contactor, and starts the DC input maximum power tracking function. The second switching state 416 can be converted to the Day state 410.

For the second switching state 416, the photovoltaic inverter device 30 initiates a DC input maximum power tracking function, and the second state machine transitions from the second switching state 416 to the Day state 410.

The operating state of the second state machine is related to the synchronization time, and the second state machine state rotation is accompanied by one day and night. The aforementioned time periods of day, evening, night, and early morning may be set according to experience values, and the set time periods may be changed according to control instructions.

Through the switching of the states of the second state machine, during the day, the photovoltaic inverter device 30 operates in the Day state 410, on the one hand, the active power is transmitted to the power grid, and the clean energy is converted into the network, and on the other hand, the power plant controller is dispatched. Output reactive power compensation power and harmonic compensation power to achieve power quality monitoring and treatment at the power station level. At night, the photovoltaic inverter device 30 can seamlessly switch to the Night state 414, without stopping, accepting power plant controller scheduling, outputting reactive power compensation power and harmonic compensation power, and realizing power quality monitoring and treatment at the power station level. Photovoltaic power plant system, according to the design of the required power output capacity P, reactive power compensation capacity Q and harmonic compensation capacity F (where the active capacity is F _p , the reactive capacity is F _q ), determine the appropriate PV inverter equipment The capacity M of 30 is:

Obviously M<P+Q+F. The way in which the photovoltaic power plant system operates (ie, the operation mode of the photovoltaic inverter device 30), on the one hand, the photovoltaic inverter device 30 outputs active power according to the maximum output capacity of the photovoltaic array (the night output is 0), on the other hand, The power station controller analyzes and processes the voltage and current signals of the nodes to be compensated, and allocates reactive compensation components and harmonic compensation components to each 24h all-weather PV inverter device according to the remaining capacity rules to realize the power station level. Power quality monitoring and treatment, without the need to introduce additional reactive power compensation equipment and harmonic compensation equipment, thereby effectively reducing the cost of building stations and operation and maintenance costs of photovoltaic power plants.

The power control method in the preferred embodiment will be described in conjunction with the structure, possible implementation, and working machine of the photovoltaic inverter device 30 described above. FIG. 5 is a flowchart 1 of a power control method according to a preferred embodiment of the present disclosure. As shown in FIG. 5, the flow includes the following steps:

Step S502, receiving a control instruction sent by the power station controller;

Step S504, determining a reactive power compensation amount and each harmonic compensation amount according to the received control instruction;

Step S506, determining, in a case where the photovoltaic inverter device is in an operating state, an operating state in the second state machine in which the photovoltaic inverter device is located;

Step S508, performing power output according to the determined reactive power compensation amount, each harmonic compensation amount, and the working state.

Through the above technical solutions of the embodiments of the present disclosure, it is not necessary to additionally introduce a reactive power compensation device and a harmonic compensation device, thereby effectively reducing the cost of establishing a station and an operation and maintenance cost of the photovoltaic power station.

As an alternative, PV inverters operating 24 hours a day can also perform reactive power compensation or harmonic compensation only, reducing the additional power quality management equipment (including reactive power compensation equipment and harmonic compensation equipment). Thereby effectively reducing the cost of building stations and operating and maintenance costs of photovoltaic power plants.

Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, by hardware, but in many cases, the former is A better implementation. Based on such understanding, portions of the technical solutions of the present disclosure that contribute substantially or to the prior art may be embodied in the form of a software product stored in a storage medium (eg, ROM/RAM, disk, The optical disc includes a number of instructions for causing a terminal device (which may be a cell phone, a computer, a server, or a network device, etc.) to perform the methods described in various embodiments of the present disclosure.

Example 2

The method embodiment provided by Embodiment 2 of the present application can be executed in an inverter device or the like. Taking the operation on the inverter device as an example, FIG. 6 is a block diagram of the hardware structure of the power station controller of a power control method according to an embodiment of the present disclosure. As shown in FIG. 6, power plant controller 60 may include one or more (only one shown) second processor 602 (second processor 602 may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA) A processing device, etc., a second memory 604 for storing data, and a second transmission device 606 for communication functions. It will be understood by those skilled in the art that the structure shown in FIG. 6 is merely illustrative and does not limit the structure of the above electronic device. For example, the plant controller 60 may also include more or fewer components than shown in FIG. 6, or have a different configuration than that shown in FIG.

The second memory 604 can be used to store software programs and modules of the application software, such as program instructions/modules corresponding to the power control method in the embodiment of the present disclosure, and the second processor 602 runs the software program stored in the second memory 604 and Modules to perform various functional applications to And data processing, that is, to achieve the above method. The second memory 604 can include a high speed random access memory, and can also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid state memory. In some examples, the second memory 604 optionally includes memory remotely located relative to the second processor 602, which may be connected to the plant controller 60 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The second transmission device 606 is configured to receive or transmit data via a network. The network optional examples described above may include a wireless network provided by a communication provider of the plant controller 60. In one example, the second transmission device 606 includes a Network Interface Controller (NIC) that can be connected to other network devices through the base station to communicate with the Internet. In one example, the second transmission device 606 can be a Radio Frequency (RF) module for communicating with the Internet wirelessly.

In this embodiment, a power control method running on the power station controller is provided. FIG. 7 is a second flowchart of a power control method according to an embodiment of the present disclosure. As shown in FIG. 7, the flow includes the following steps:

Step S702, acquiring state information of a point to be compensated in the photovoltaic power station system;

Step S704, determining, according to the acquired state information, and the preset allocation rule, a reactive compensation component for each inverter device to compensate the reactive power of the inverter device to be compensated, and/or for a harmonic compensation component for compensating the harmonics of the compensation point to be compensated by the inverter device;

Step S706, transmitting the determined reactive compensation component and/or harmonic compensation component to the corresponding inverter device.

Through the above steps, the reactive power and/or harmonics for assigning the points to be compensated to the inverter device are compensated without additional introduction of the reactive power compensation device and/or the harmonic compensation device, thereby solving the related art. Increasing the power quality monitoring and management system unit to solve the problem of reactive power or harmonics increases the investment cost and operation and maintenance cost of photovoltaic construction stations, and reduces the cost of building stations and operation and maintenance costs of photovoltaic power plants.

Optionally, in step S704, the reactive compensation component and/or the harmonic compensation component allocated to each inverter device may be determined in various manners, for example, may be proportionally allocated according to the rated power of each inverter device. Reactive compensation component and / or harmonic compensation component. For another example, a predetermined number of inverter devices may be pre-determined to distribute the reactive compensation component and/or the harmonic compensation component in an equal manner. For another example, the allocation coefficient of each inverter device may be respectively determined according to a first remaining capacity of each inverter device and a second remaining capacity of all inverter devices in the photovoltaic power station system, wherein the first remaining capacity The root mean square value of the sum of the rated power of the inverter device and the output active power and the compensated reactive power, the second remaining capacity being the sum of the first remaining capacities of all the inverter devices, according to the determined allocation The coefficient, and the total amount of reactive power to be compensated for the point to be compensated, are respectively determined as reactive power compensation components allocated to each inverter device; and/or, according to the determined distribution coefficient, and the total amount of harmonic compensation to be compensated , respectively, determine the harmonic compensation component assigned to each inverter device.

According to the above technical solution of the embodiment of the present disclosure, according to the remaining capacity of each inverter device and the total remaining capacity of each inverter device in the photovoltaic power station system, reactive power is allocated to each inverter device according to the ratio of the remaining capacity. The compensation amount and/or harmonic compensation component fully exploits the reactive power compensation and/or harmonic capability of each inverter device, thereby avoiding waste of capacity.

Optionally, the time of each inverter device may be synchronized, and the synchronization time may be controlled by a time control device in each inverter, or may be used by the power station controller for the photovoltaic power station in the process of step S706. The synchronization time of the time synchronization of the power plant controller of the system with each inverter device is sent to the corresponding inverter device to synchronize the time of each inverter device.

Through the above technical solution of the embodiment of the present disclosure, the synchronization time of the time synchronization of the power station controller for the photovoltaic power station system and each inverter device is transmitted to the corresponding inverter device, thereby ensuring the inverter device confirmation. The accuracy of the working hours.

Optionally, the power plant controller can transmit the determined reactive power compensation component and/or the harmonic compensation component in various manners, for example, can be sent through the interface for the inverter device to determine the reactive power compensation component and/or the harmonic compensation component. Component control instructions. It can communicate with each inverter device of the PV power plant system by Modbus TCP/IP communication protocol or PLC, through the corresponding interface (physical connection The port or logical interface) sends control commands.

Through the above technical solution of the embodiment of the present disclosure, the inverter device uses the Modbus TCP/IP communication protocol or the PLC to communicate with the inverter device of the photovoltaic power station system, and sends a control command to realize the inverter device through the power station controller. Unified control.

Based on the above embodiments and alternative embodiments, in order to illustrate the entire process interaction of the solution, in the preferred embodiment, a power control method is provided. The power control method can be operated in a power plant controller as shown in FIG. 8. As shown in FIG. 8, the power station controller 80 includes an electric meter unit 802, a processing unit 804, a communication unit 806, and a time synchronization unit 808.

The meter unit 802 is an input end of the power station controller 80 for detecting the state quantity of the sampling connection point, and may be selected as the state quantity of the power station reactive power and the harmonic component to be compensated, including but not limited to voltage, current, and active power. Total power, power factor, total amount of reactive power to be compensated, and total amount of harmonics to be compensated. The meter unit 802 is coupled to the processing unit 804.

The processing unit 804 reads the sampling data of the meter unit 802, including but not limited to the voltage, current, and total amount of active power, the power factor, the total amount of reactive power to be compensated, and the total amount of harmonics to be compensated, and is allocated according to a preset rule. Reactive power compensation component and each harmonic compensation component of each inverter. The reactive power compensation component and each harmonic compensation component are respectively represented by equivalent current components. The synchronization time of the time synchronization unit 808 is read. The processing unit 802 sends the reactive compensation component, the harmonic compensation component, and the synchronization time of each inverter device to the communication unit 806.

The preset allocation rule of the processing unit 806: the reactive power component and the harmonic compensation component are represented by the equivalent current component, according to the formula:

The reactive power compensation component of the nth inverter and the equivalent d, q-axis current command increment value of each harmonic compensation component are allocated. Wherein, M _n is the n-th power rating of the inverter, the n-th stage P _n is the inverter output active power, Q _n is the n inverters to compensate reactive power, K is the partition coefficient _n,

The active current corresponding to the ith harmonic,

For the reactive current corresponding to the ith harmonic,

The amount of active current compensation corresponding to the ith harmonic of the nth inverter,

For the reactive compensation amount assigned to the nth inverter,

The amount of reactive current compensation corresponding to the i-th (i ≥ 2)th harmonic assigned to the nth inverter. The nth inverter is in operation, and the inverter device is a photovoltaic inverter operating 24 hours a day; n is a positive integer and is not greater than the number m of inverters, and i and m are positive integers.

It should be noted here that p in the above formula corresponds to the p-axis, that is, active, q corresponds to reactive power in the q-axis, h represents harmonics, and represents reactive power compensation, that is,

For the reactive compensation amount assigned to the nth inverter,

with

For each harmonic compensation amount, among them,

The amount of reactive current compensation corresponding to the i-th (i ≥ 2)th harmonic assigned to the nth inverter.

I _fq ,

It can be determined according to the status information of the point to be compensated.

The communication unit 806 is an interaction interface between the power station controller and each of the inverter devices for data interaction with the monitoring unit 314 of each of the photovoltaic inverter devices 30. The data transmitted by the communication unit 806 to the inverter device includes, but is not limited to, a reactive compensation component corresponding to the inverter device, each harmonic compensation component, and a synchronization time. The communication unit 806 receives data from the inverter device, including but not limited to: corresponding inverter rated power, active power, reactive power, inverter number, inverter operating state (including in the first state machine and the first The operating state in the second state machine).

The communication mode between the communication unit 806 and each inverter device can be Modbus TCP/IP communication or PLC power carrier communication.

The time synchronization unit 808, optionally, uses a Global Positioning System (GPS) satellite synchronization technology to output a synchronization time to ensure stable reliability of the power station system; meanwhile, the synchronization time is sent to the power station through the communication unit 806. For each PV inverter device, the PV inverter device can confirm the working period according to the synchronization time.

The power plant controller 80 can be associated with the photovoltaic power plant system in which the photovoltaic inverter device 30 is located. Various forms are described below with reference to FIGS. 9 and 10.

The photovoltaic power station system shown in Figure 9 includes but is not limited to: PV module array, DC combiner box, PV inverter equipment for 24h 24 hours, AC combiner box, low voltage isolation transformer, grid common connection point (Point of Common) Coupling, referred to as PCC), plant controller, local load. Where X is a positive integer. It should be noted that the photovoltaic power station system shown in FIG. 9 does not include an additional reactive power compensation device and a harmonic compensation device. The photovoltaic module array is connected to the input side of the DC combiner box, and the output side of the DC combiner box is connected with the corresponding DC input end of the photovoltaic inverter device 30 working 24 hours a day, and the inverter AC grid control module is connected with the input port of the AC combiner box. The output of the AC combiner box is connected to the primary side of the low-voltage isolating transformer, and the secondary side of the low-voltage isolating transformer is connected to the local load and the PCC of the power grid. The input end of the power plant controller is the local load connection point of the power station to be compensated, and the output end of the power station controller 80 is The monitoring unit 314 of each photovoltaic inverter device 30 is respectively connected, and adopts Modbus TCP/IP communication protocol or PLC power carrier communication.

Alternatively, an isolation transformer can be added between the photovoltaic inverter device 30 and the AC combiner box operating 24 hours a day in FIG.

10 is a second photovoltaic power plant system using the 24h all-weather photovoltaic inverter device shown in FIG. 3 according to an embodiment of the present disclosure, including but not limited to: photovoltaic module array, DC combiner box, 24h working around the clock. Photovoltaic inverter equipment X, AC combiner box, low voltage isolation transformer, main transformer, grid common connection point PCC, power station controller. Where X is a positive integer. It should be noted that the photovoltaic power station system in FIG. 10 does not include an additional reactive power compensation device and a harmonic compensation device. The photovoltaic module array is connected to the input side of the DC combiner box, and the output side of the DC combiner box is connected with the corresponding DC input end of the photovoltaic inverter device 30 working 24 hours a day, and the inverter AC grid control module is connected with the input port of the AC combiner box. The output of the AC combiner box is connected to the primary side of the low-voltage isolating transformer, the secondary side of the low-voltage isolating transformer is connected to the input end of the main transformer, the output end of the main transformer is connected to the PCC of the power grid, and the input end of the power station controller 80 is the power station to be compensated for the main transformer output. The endpoint, the output of the power plant controller 80 is connected to the monitoring unit 314 of each photovoltaic inverter device 30, respectively, using Modbus TCP/IP communication protocol or PLC power carrier communication.

Optionally, in Figure 10, an isolation transformer can be added between the photovoltaic inverter device and the AC combiner box operating 24 hours a day.

The power control method in the preferred embodiment will be described in conjunction with the structure of the above-described power plant controller 80 and the photovoltaic power plant system. 11 is a second flowchart of a power control method according to a preferred embodiment of the present disclosure. As shown in FIG. 11, the flow includes the following steps:

Step S1102: Obtain status information of a point to be compensated of the photovoltaic power station;

The power station controller of the photovoltaic power station system obtains the state information of the photovoltaic power station to be compensated. Optionally, in combination with the photovoltaic power station system shown in FIG. 9, the photovoltaic power plant to be compensated point is a local load connection point; in combination with the photovoltaic power station system shown in FIG. 10, the photovoltaic power plant to be compensated point is the output terminal of the main transformer. The state information of the point to be compensated is sampled and analyzed by the meter unit of the power station controller, including but not limited to: voltage, current and total amount of active power, power factor, total amount of reactive power to be compensated, and total amount of harmonics to be compensated.

Step S1104: Allocating a reactive compensation component and each harmonic compensation component for each inverter in the running state according to a preset rule;

The power station controller allocates a reactive compensation component and each harmonic compensation component to each inverter in the running state according to a preset rule. Optionally, the allocation rules may be as shown in the aforementioned formulas (1)-(3).

Step S1106, the reactive compensation component and each harmonic compensation component allocated to each inverter in the running state in the power station are sent to the corresponding inverter.

The photovoltaic inverter outputs active power, reactive power and harmonic compensation power to the grid according to the command of the power plant controller and the output capability of the component.

The PV inverter device provided in accordance with the above preferred embodiment according to the reactive power compensation command and the harmonic compensation command of the power station controller and the actual output capability of the photovoltaic module in each operating 24h all-weather photovoltaic inverter The state machine logic is run to deliver active power, reactive power, and harmonic compensation power to the AC grid side to achieve power management.

The power plant controller provided by the preferred embodiment combines the 24 h all-weather photovoltaic inverter operating state machine provided by the above embodiments to realize power quality monitoring and treatment at the power station level. No need to lead Into additional power quality management equipment (including reactive power compensation equipment and harmonic compensation equipment), thereby effectively reducing the cost of photovoltaic power station construction and operation and maintenance costs.

As an alternative, reactive power compensation or harmonic compensation can be performed only by PV inverters operating 24 hours a day, reducing the additional power quality management equipment (including reactive power compensation equipment and harmonic compensation equipment). Therefore, the photovoltaic station construction cost and operation and maintenance cost are effectively reduced.

Example 3

In the present embodiment, a power control device is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and has not been described again. As used below, the term "module" may implement a combination of software and/or hardware of a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware, or a combination of software and hardware, is also possible and contemplated.

FIG. 12 is a structural block diagram 1 of a power control apparatus according to an embodiment of the present disclosure. As shown in FIG. 12, the apparatus includes:

The receiving module 122 is configured to receive, by the inverter device, a control instruction, where the control instruction carries a first parameter of determining a reactive power compensation amount for the inverter device to compensate the reactive power of the photovoltaic power station system in which the inverter device is located And/or used to determine the photovoltaic power of the inverter device a second parameter of the harmonic compensation amount of the harmonics of the station system;

The first determining module 124 is connected to the receiving module 122, and is configured to determine, by the inverter device, a reactive power compensation amount for the reactive power compensation of the photovoltaic power station system by the inverter device according to the first parameter; and/or according to the first The second parameter determines the harmonic compensation amount of the harmonic compensation of the photovoltaic power station system by the inverter device;

The compensation module 126 is connected to the first determining module 124, and is configured to compensate the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and/or, according to the harmonic compensation amount, the photovoltaic power station The harmonics of the system are compensated.

FIG. 13 is a structural block diagram of a compensation module 126 of a power control device according to an embodiment of the present disclosure. As shown in FIG. 13, the compensation module 126 includes:

The first determining unit 132 is configured to determine, in the case that the inverter device is in an operating state, the preset state of the inverter device, wherein the preset state is a state in the predetermined state machine;

The compensation unit 134 is connected to the first determining unit 132, and is configured to compensate the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount and the preset state; and/or, according to the determination The harmonic compensation amount and the preset state compensate the harmonics of the photovoltaic power station system.

FIG. 14 is a structural block diagram of a receiving module 132 of a power control apparatus according to an embodiment of the present disclosure. As shown in FIG. 14, the receiving module 132 includes:

The receiving unit 142 is configured to communicate with the power station controller of the photovoltaic power station system by using a Modbus transmission control protocol/network protocol TCP/IP communication protocol or a power carrier PLC, and receive a control instruction sent by the power station controller.

It should be noted that each of the above modules may be implemented by software or hardware. For the latter, the foregoing may be implemented by, but not limited to, the foregoing modules are all located in the same processor; or, the above modules are in any combination. The forms are located in different processors.

Example 4

An inverter device is also provided in this embodiment. FIG. 15 is a structural block diagram of an inverter device according to an embodiment of the present disclosure. As shown in FIG. 15, the system includes the first power control in the above embodiment. Device 152.

Example 5

16 is a structural block diagram 2 of a power control apparatus according to an embodiment of the present disclosure. As shown in FIG. 16, the apparatus includes:

The obtaining module 162 is configured to obtain state information of a point to be compensated in the photovoltaic power station system;

The second determining module 164 is connected to the obtaining module 162, and is configured to determine, according to the acquired state information and the preset allocation rule, the reactive power allocated to each inverter device for the inverter device to be compensated. a reactive compensation component for compensating and/or a harmonic compensation component for compensating for harmonics of the device to be compensated by the inverter device;

The sending module 166 is connected to the second determining module 164, and is configured to send the determined reactive compensation component and/or harmonic compensation component to the corresponding inverter device.

FIG. 17 is a structural block diagram of a second determining module 164 of a power control apparatus according to an embodiment of the present disclosure. As shown in FIG. 17, the second determining module 164 includes:

The second determining unit 172 is configured to determine a distribution coefficient of each inverter device according to a first remaining capacity of each inverter device and a second remaining capacity of all the inverter devices in the photovoltaic power station system, where The first remaining capacity is a root mean square value of a squared difference between the rated power of the inverter device and the output active power and the compensated reactive power, and the second remaining capacity is a sum of the first remaining capacities of all the inverter devices;

The third determining unit 174 is connected to the second determining unit 172, and is configured to determine each inverter device according to the determined allocation coefficient and the total amount of reactive power to be compensated for the point to be compensated. The distributed reactive compensation component; and/or, according to the determined distribution coefficient and the total amount of harmonics to be compensated of the point to be compensated, respectively determine the harmonic compensation component allocated for each inverter device.

Optionally, the sending module 166 is further configured to send a synchronization time of the power plant controller of the photovoltaic power station system and each inverter device to the corresponding inverter device.

Optionally, the sending module 166 is further configured to communicate with the inverter device of the photovoltaic power station system by using a Modbus transmission control protocol/network protocol TCP/IP communication protocol or a power carrier PLC, and the transmitted component is allocated to each inverter device. The control command of the reactive compensation component and/or the harmonic compensation component.

Example 6

In the present embodiment, a power plant controller is also provided. FIG. 18 is a structural block diagram of a power plant controller according to an embodiment of the present disclosure. As shown in FIG. 18, the system includes the second power control device 182 in the above embodiment. .

Example 7

Embodiments of the present disclosure also provide a storage medium including a stored program, wherein the program described above executes the method of any of the above.

Optionally, in the embodiment, the foregoing storage medium may be configured to store program code for performing the following steps:

S1. The inverter device receives a control instruction, where the control instruction carries a first parameter and/or a used reactive power compensation amount for determining that the inverter device compensates the reactive power of the photovoltaic power station system in which the inverter device is located. a second parameter for determining a harmonic compensation amount for the inverter device to compensate for harmonics of the photovoltaic power plant system in which the inverter device is located;

S2. The inverter device determines, according to the first parameter, a reactive power compensation amount that the inverter device performs reactive power compensation on the photovoltaic power station system; and/or determines the light of the inverter device according to the second parameter. The harmonic compensation amount of the harmonic compensation system of the power plant system;

S3. The inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and/or compensates the harmonics of the photovoltaic power station system according to the harmonic compensation amount.

Optionally, the storage medium is further arranged to store program code for performing the following steps:

The inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and/or compensates the harmonics of the photovoltaic power station system according to the harmonic compensation amount, including:

S1. In the case that the inverter device is in an operating state, the inverter device determines a preset state in which the inverter device is located, where the preset state is a state in the predetermined state machine;

S2, the inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount and the preset state; and/or, according to the determined harmonic compensation amount, and the preset state, the photovoltaic The harmonics of the power station system are compensated.

The predetermined state machine includes: a first state, a first switching state, a second state, and a second switching state;

The first state is that the DC output power output by the inverter device is greater than zero, the active power output is a preset value, and the reactive power compensation amount is the determined reactive power compensation amount and/or the harmonic compensation amount is a determined harmonic. The state of the wave compensation amount; the first switching state is a transition state of the first state to the second state switching; the second state is that the DC output power and the active power output of the inverter device are zero, and the reactive power compensation amount is determined. The reactive power compensation amount and/or the harmonic compensation amount is a state of the determined harmonic compensation amount; the second switching state is a transition state of the second state to the first state switching; the first state, the first switching state, the second state The state and the second switching state are cyclically cycled in a 24-hour period.

The workflow of the scheduled state machine includes:

S1. In a case where the preset state is the first state, the inverter device determines whether the inverter device meets the first switching condition, where the first switching condition is a DC for identifying the inverter device. The output DC parameter is smaller than the first preset threshold, and the duration of the DC parameter is greater than or equal to the first time threshold, or the DC parameter used to identify the DC output of the inverter device is less than the first preset threshold, and the DC parameter is The duration of the duration is greater than or equal to the first time threshold, and the synchronization time of the inverter device is within the first preset threshold range, and the DC parameter is at least one of the following: DC input power, DC input voltage, DC input current; When the inverter meets the first switching condition, the inverter switches the working state of the inverter from the first state to the first switching state;

S2, in a case where the preset state is the first switching state, the inverter device turns off the DC input maximum power tracking function of the inverter device, and adjusts the DC input voltage of the inverter device according to the open circuit voltage of the inverter device, Disconnecting the DC contactor of the inverter device, and stabilizing the bus voltage of the inverter device according to the first bus voltage regulation value; the duration of the bus voltage voltage regulation at the first bus voltage is greater than or equal to the first switching time threshold When the inverter device switches the first switching state to the second state;

S3, in a case where the preset state is the second state, the inverter device determines whether the inverter meets the second switching condition, wherein the second switching condition is that the DC parameter for identifying the DC output of the inverter device is greater than Or equal to the second preset threshold, and the duration of the DC parameter is greater than or equal to the second time threshold, or the DC parameter used to identify the DC output of the inverter device is greater than or equal to the first preset threshold, and the DC parameter is continued. The duration is greater than or equal to the second time threshold, and the synchronization time of the inverter device is within the second preset threshold range, and the DC parameter is at least one of the following: DC input power, DC input voltage, DC input current; When the inverter meets the second switching condition, the inverter device switches the working state of the inverter from the second state to the second switching state;

S4, in the case that the preset state is the second switching state, the inverter device tracks the DC voltage of the inverter device by the bus voltage of the inverter device, and sucks the DC contactor of the inverter device to start The DC input maximum power tracking function of the inverter device switches the second switching state to the first state.

The inverter device receiving control instructions includes:

The Modbus transmission control protocol/network protocol TCP/IP communication protocol or power carrier PLC is used to communicate with the power plant controller of the photovoltaic power station system, and the control command sent by the power station controller is received.

Optionally, in this embodiment, the foregoing storage medium may include, but not limited to, a USB flash drive, a Read-Only Memory (ROM), a Random Access Memory (RAM), a mobile hard disk, and a magnetic memory. A variety of media that can store program code, such as a disc or a disc.

Optionally, in this embodiment, the processor executes, according to the stored program code in the storage medium, the inverter device receives the control instruction, where the control instruction carries the photovoltaic power station for determining the pair of the inverter device a first parameter of the reactive power compensation amount of the reactive power of the system and/or a second parameter for determining a harmonic compensation amount for the inverter device to compensate for the harmonic of the photovoltaic power plant system; The transformer device determines, according to the first parameter, a reactive power compensation amount for the reactive power compensation of the photovoltaic power station system by the inverter device; and/or determines, according to the second parameter, the harmonic compensation of the photovoltaic device system by the inverter device. Harmonic compensation amount; the inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and/or compensates the harmonics of the photovoltaic power station system according to the harmonic compensation amount.

Optionally, in this embodiment, the processor executes according to the stored program code in the storage medium: the inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and/or, Compensating for the harmonics of the photovoltaic power station system according to the harmonic compensation amount includes: when the inverter device is in the running state, the inverter device determines a preset state in which the inverter device is located, wherein the preset state a state in the predetermined state machine; the inverter device compensates the reactive power of the photovoltaic power plant system according to the determined reactive power compensation amount and the preset state; and/or, according to the determined harmonic compensation amount, and The preset state compensates for the harmonics of the photovoltaic power plant system.

Optionally, in this embodiment, the processor executes according to the stored program code in the storage medium: the predetermined state machine includes: a first state, a first switching state, a second state, and a second switching state The first state is that the DC output power output by the inverter device is greater than zero, the active power output is a preset value, and the reactive power compensation amount is determined by determining the reactive power compensation amount and/or the harmonic compensation amount. The state of the harmonic compensation amount; the first switching state is a transition state of the first state to the second state switching; the second state is that the DC output power and the active power output of the inverter device are zero, and the reactive power compensation amount is The determined reactive power compensation amount and/or the harmonic compensation amount is a state of the determined harmonic compensation amount; the second switching state is a transition state in which the second state is switched to the first state; the first state, the first switching state, The second state and the second switching state are cyclically cycled in a 24-hour period.

Optionally, in this embodiment, the processor executes according to the stored program code in the storage medium: the workflow of the predetermined state machine includes: when the preset state is the first state, the inverter device determines the inverter Whether the device meets the first switching condition, wherein the first switching condition is that the DC parameter for identifying the DC output of the inverter device is less than the first preset threshold, and the duration of the DC parameter is greater than or equal to the first time threshold, Or the DC parameter used to identify the DC output of the inverter device is smaller than the first preset threshold, the duration of the DC parameter is greater than or equal to the first time threshold, and the synchronization time of the inverter device is in the first preset threshold range. The DC parameter is at least one of the following: DC input power, DC input voltage, and DC input current; when the judgment result is that the inverter meets the first switching condition, the inverter operates the inverter by the first Switching to a first switching state; in the case where the preset state is the first switching state, the inverter device turns off the inverter device The flow input maximum power tracking function adjusts the DC input voltage of the inverter device according to the open circuit voltage of the inverter device, disconnects the DC contactor of the inverter device, and stabilizes the inverter device according to the first bus voltage regulation value. Bus voltage; the inverter device switches the first switching state to the second state when the duration of the bus voltage voltage regulation is greater than or equal to the first switching time threshold; the preset state is the second state The inverter device determines whether the inverter meets the second switching condition, wherein the second switching condition is that the DC parameter for identifying the DC output of the inverter device is greater than or equal to a second preset threshold, and the DC The duration of the parameter is greater than or equal to the second time threshold, or the DC parameter used to identify the DC output of the inverter device is greater than or equal to the first preset threshold, and the duration of the DC parameter is greater than or equal to the second time threshold, and Synchronization time bit of the inverter device Within the second preset threshold range, the DC parameter is at least one of the following: DC input power, DC input voltage, DC input current; if the result of the determination is that the inverter meets the second switching condition, the inverter device will The working state of the inverter is switched from the second state to the second switching state; in the case that the preset state is the second switching state, the inverter device tracks the bus voltage of the inverter device to track the DC input of the inverter device The voltage value, the DC contactor of the inverter device is activated, and the DC input maximum power tracking function of the inverter device is started, and the second switching state is switched to the first state.

Optionally, in this embodiment, the processor executes according to the stored program code in the storage medium: the inverter device receives the control instruction, including: using a Modbus transmission control protocol/network protocol TCP/IP communication protocol or a power carrier PLC and The power plant controller of the photovoltaic power plant system communicates and receives control commands sent by the power plant controller.

Embodiments of the present disclosure also provide a processor for running a program, wherein the program executes the steps of any of the above methods when executed.

For an alternative example in this embodiment, reference may be made to the examples described in the foregoing embodiments and the optional embodiments, and details are not described herein again.

Example 8

Embodiments of the present disclosure also provide a storage medium. Optionally, in the embodiment, the foregoing storage medium may be configured to store program code for performing the following steps:

S1, obtaining state information of a point to be compensated in the photovoltaic power station system;

S2. Determine, according to the acquired state information, and the preset allocation rule, a reactive compensation component for each inverter device to compensate the reactive power of the inverter device to be compensated, and/or for The harmonic compensation component that the transformer device compensates for the harmonics of the compensation point;

S3. Send the determined reactive compensation component and/or harmonic compensation component to the corresponding inverter device.

According to the obtained status information and the preset allocation rule, respectively determined as each inverter device The distributed reactive compensation component for the reactive power of the inverter device to be compensated for the compensation and/or the harmonic compensation component for compensating the harmonics of the device to be compensated for the inverter device include:

S1. Determine a distribution coefficient of each inverter device according to a first remaining capacity of each inverter device and a second remaining capacity of all inverter devices in the photovoltaic power station system, where the first remaining capacity is inverse The root mean square value of the rated power of the transformer device and the squared difference between the output active power and the compensated reactive power, and the second remaining capacity is the sum of the first remaining capacities of all the inverter devices;

S2, determining, according to the determined distribution coefficient and the total amount of reactive power to be compensated, the reactive compensation component allocated to each inverter device; and/or, according to the determined distribution coefficient, and the point to be compensated The total amount of harmonics to be compensated is determined as the harmonic compensation component assigned to each inverter device.

In the process of transmitting the determined reactive power compensation component and/or the harmonic compensation component to the corresponding inverter device, the method further includes:

The synchronization time of the power plant controller for the photovoltaic power plant system and each inverter device is time-synchronized and transmitted to the corresponding inverter device.

Optionally, in this embodiment, the processor performs: acquiring state information of a point to be compensated in the photovoltaic power station system according to the stored program code in the storage medium; determining, according to the acquired state information, and a preset allocation rule, respectively A reactive compensation component for each inverter device that compensates for reactive power of the inverter device to be compensated for and/or a harmonic compensation component for compensation of harmonics of the device to be compensated for the inverter device And transmitting the determined reactive compensation component and/or harmonic compensation component to the corresponding inverter device.

Optionally, in this embodiment, the processor executes according to the stored program code in the storage medium. Line: determining the reactive compensation component for each inverter device to compensate the reactive power of the compensation point to be compensated according to the obtained state information and the preset allocation rule, and/or for the inverse The harmonic compensation component for compensating the harmonics of the compensation point to be compensated includes: determining, according to the first remaining capacity of each inverter device and the second remaining capacity of all the inverter devices in the photovoltaic power plant system, respectively a distribution coefficient of the inverter device, wherein the first remaining capacity is a root mean square value of a squared difference between the rated power of the inverter device and the output active power and the compensated reactive power, and the second remaining capacity is all inverters The sum of the first remaining capacity of the device; determining the reactive compensation component assigned to each inverter device according to the determined distribution coefficient and the total amount of reactive compensation to be compensated; and/or, according to the determined The distribution coefficient, and the total amount of harmonics to be compensated for the point to be compensated, are respectively determined as harmonic compensation components allocated to each inverter device.

Optionally, in this embodiment, the processor performs, according to the stored program code in the storage medium: in the process of transmitting the determined reactive compensation component and/or harmonic compensation component to the corresponding inverter device. The method further includes: synchronizing the time synchronization of the power plant controller for the photovoltaic power station system with each inverter device, and transmitting the synchronization time to the corresponding inverter device.

It will be apparent to those skilled in the art that the various modules or steps of the present disclosure described above can be implemented by a general-purpose computing device that can be centralized on a single computing device or distributed across a network of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps thereof are fabricated as a single integrated circuit module. As such, the disclosure is not limited to any specific combination of hardware and software.

The above description is only a preferred embodiment of the present disclosure, and is not intended to limit the disclosure, Various changes and modifications of the present disclosure are possible to those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and scope of the present disclosure are intended to be included within the scope of the present disclosure.

Industrial applicability

The present disclosure relates to the field of communications, and provides a power control method, device, inverter device and power station controller, which uses an inverter device to react to a reactive power of a photovoltaic power plant system or a harmonic of a photovoltaic power plant system according to a received control command. The wave is compensated without additional introduction of reactive power compensation equipment and/or harmonic compensation equipment, which solves the problem of increasing the investment cost of photovoltaic construction by solving the problem of reactive power or harmonics by increasing the power quality monitoring and management system unit in the related art. The problem of operation and maintenance cost reduces the cost of building and operating costs of photovoltaic power plants.

Claims

A power control method includes:

The inverter device receives a control command, wherein the control command carries a first parameter for determining a reactive power compensation amount for the inverter device to compensate for reactive power of the photovoltaic power plant system in which the inverter device is located Or a second parameter for determining a harmonic compensation amount for the inverter device to compensate for harmonics of the photovoltaic power plant system in which the inverter device is located;

Determining, by the inverter device, a reactive power compensation amount for reactive power compensation of the photovoltaic power station system by the inverter device according to the first parameter; and/or determining, according to the second parameter, the The harmonic compensation amount of the harmonic compensation of the photovoltaic power station system by the inverter device;

The inverter device compensates reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and/or, according to the harmonic compensation amount, pairs the harmonics of the photovoltaic power station system Make compensation.
The method of claim 1 wherein said inverter device compensates said reactive power of said photovoltaic power plant system based on said determined amount of reactive power compensation; and/or, according to said harmonic The wave compensation amount compensates for the harmonics of the photovoltaic power plant system including:

In the case that the inverter device is in an operating state, the inverter device determines a preset state in which the inverter device is located, wherein the preset state is a state in a predetermined state machine;

The inverter device compensates the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount and the preset state; and/or according to the determined harmonic The amount of compensation, and the predetermined state, compensates for the harmonics of the photovoltaic power plant system.
The method of claim 2, wherein the predetermined state machine comprises: a first state, a first switching state, a second state, and a second switching state;

The first state is that the DC output power output by the inverter device is greater than zero, the active power output is a preset value, and the reactive power compensation amount is the determined reactive power compensation amount and/or harmonic. The compensation amount is a state of the determined harmonic compensation amount; the first switching state is a transition state in which the first state is switched to the second state; and the second state is a state of the inverter device The DC output power and the active power output are zero, and the reactive power compensation amount is a state in which the determined reactive power compensation amount and/or the harmonic compensation amount is the determined harmonic compensation amount; the second switching state a transition state for switching the second state to the first state; the first state, the first switching state, the second state, and the second switching state are cyclically cycled in a 24-hour period.
The method of claim 3 wherein the workflow of the predetermined state machine comprises:

When the preset state is the first state, the inverter device determines whether the inverter device meets the first switching condition, where the first switching condition is used to identify the inverter The DC parameter of the DC output of the device is less than the first preset threshold, and the duration of the DC parameter is greater than or equal to the first time threshold, or the DC parameter used to identify the DC output of the inverter device is smaller than the first parameter. a preset threshold, the duration of the DC parameter is greater than or equal to the first time threshold, and the synchronization time of the inverter device is within a first preset threshold range, and the DC parameter is at least one of the following: DC Input power, DC input voltage, DC input current; if the result of the determination is that the inverter meets the first switching condition, the inverter will operate the inverter by the first The state is switched to the first switching state;

In a case where the preset state is a first switching state, the inverter device turns off a DC input maximum power tracking function of the inverter device, and adjusts the inverse according to an open circuit voltage of the inverter device. a DC input voltage of the transformer device, disconnecting the DC contactor of the inverter device, and regulating a bus voltage of the inverter device according to a first bus voltage regulation value; When the duration of a bus voltage is greater than or equal to a first switching time threshold, the inverter device switches the first switching state to the Second state

If the preset state is the second state, the inverter device determines whether the inverter meets a second switching condition, where the second switching condition is used to identify the inverter The DC parameter of the DC output of the device is greater than or equal to the second preset threshold, and the duration of the DC parameter is greater than or equal to the second time threshold, or the DC parameter used to identify the DC output of the inverter device is greater than Or equal to the first preset threshold, the duration of the DC parameter is greater than or equal to the second time threshold, and the synchronization time of the inverter device is within a second preset threshold range, and the DC parameter is at least a DC input power, a DC input voltage, and a DC input current; if the result of the determination is that the inverter meets the second switching condition, the inverter device sets the working state of the inverter by Switching the second state to a second switching state;

In the case that the preset state is the second switching state, the inverter device tracks the DC voltage value of the inverter device by the bus voltage of the inverter device, and pulls the inverter The DC contactor of the device activates a DC input maximum power tracking function of the inverter device to switch the second switching state to the first state.
The method according to any one of claims 1 to 4, wherein the receiving, by the inverter device, the control instruction comprises:

The control command sent by the power station controller is received by using a Modbus transmission control protocol/network protocol TCP/IP communication protocol or a power carrier PLC to communicate with a power plant controller of the photovoltaic power station system.
A power control method includes:

Obtaining state information of a point to be compensated in the photovoltaic power plant system;

Determining, according to the obtained state information, and a preset allocation rule, a reactive compensation component for each inverter device to compensate the reactive power of the to-be-compensated point for the inverter device / or for the inverter device to the point to be compensated Harmonic compensation component for harmonic compensation;

The determined reactive compensation component and/or the harmonic compensation component are transmitted to a corresponding inverter device.
The method according to claim 6, wherein the inverter device is allocated to each of the inverter devices according to the acquired state information and the preset allocation rule. The reactive compensation component that compensates for the reactive power of the point to be compensated and/or the harmonic compensation component that is used by the inverter device to compensate for the harmonic of the point to be compensated includes :

Determining, respectively, a distribution coefficient of each of the inverter devices according to a first remaining capacity of each of the inverter devices and a second remaining capacity of all inverter devices in the photovoltaic power plant system, wherein The first remaining capacity is a root mean square value of a squared difference between the rated power of the inverter device and the output active power and the compensated reactive power, where the second remaining capacity is all of the inverter devices Describe the sum of the first remaining capacity;

Determining, according to the determined allocation coefficient, and the total amount of reactive power to be compensated of the point to be compensated, the reactive compensation component allocated for each of the inverter devices; and/or, according to the determined And a distribution coefficient, and a total amount of harmonics to be compensated of the point to be compensated, respectively determined as the harmonic compensation component allocated by each of the inverter devices.
The method according to claim 6 or 7, wherein, in the process of transmitting the determined reactive compensation component and/or the harmonic compensation component to the corresponding inverter device, the method further includes:

A synchronization time for time synchronization of the power plant controller for the photovoltaic power plant system with each of the inverter devices is transmitted to the corresponding inverter device.
A power control device comprising:

a receiving module, configured to receive, by the inverter device, a control command, wherein the control command carries a reactive power compensation amount for determining that the inverter device compensates for reactive power of the photovoltaic power station system in which the inverter device is located First parameter and/or for determining the inverter a second parameter of the harmonic compensation amount that the device compensates for the harmonics of the photovoltaic power plant system in which it is located;

a first determining module, configured to determine, according to the first parameter, a reactive power compensation amount that the inverter device performs reactive power compensation on the photovoltaic power station system according to the first parameter; and/or, according to the Determining, by the second parameter, a harmonic compensation amount for harmonic compensation of the photovoltaic power station system by the inverter device;

a compensation module, configured to: the inverter device compensates reactive power of the photovoltaic power station system according to the determined reactive power compensation amount; and/or, according to the harmonic compensation amount, the photovoltaic power station The harmonics of the system are compensated.
The apparatus of claim 9 wherein said compensation module comprises:

a first determining unit, configured to determine, in a case where the inverter device is in an operating state, the inverter device determines a preset state in which the inverter device is located, wherein the preset state is a predetermined State in the state machine;

a compensation unit, configured to compensate the reactive power of the photovoltaic power station system according to the determined reactive power compensation amount and the preset state; and/or, according to determining The harmonic compensation amount, and the preset state, compensates for the harmonic of the photovoltaic power station system.
The apparatus according to claim 9 or 10, wherein the receiving module comprises:

The receiving unit is configured to communicate with the power station controller of the photovoltaic power station system by using a Modbus Transmission Control Protocol/Network Protocol TCP/IP communication protocol or a power carrier PLC, and receive the control instruction sent by the power station controller.
An inverter device comprising the device of any one of claims 9 to 11.
A power control device comprising:

Obtaining a module, configured to obtain state information of a point to be compensated in the photovoltaic power station system;

The second determining module is configured to determine, according to the acquired state information, and the preset allocation rule, the reactive power allocated to each inverter device for the inverter device to the point to be compensated a compensated reactive compensation component and/or a harmonic compensation component for the inverter device to compensate for harmonics of the point to be compensated;

And a sending module, configured to send the determined reactive compensation component and/or the harmonic compensation component to a corresponding inverter device.
The apparatus of claim 13, wherein the second determining module comprises:

a second determining unit, configured to determine, according to a first remaining capacity of each of the inverter devices, and a second remaining capacity of all inverter devices in the photovoltaic power station system, respectively, determining each of the inverter devices a distribution coefficient, wherein the first remaining capacity is a root mean square value of a squared difference between a rated power of the inverter device and an output active power and a compensated reactive power, wherein the second remaining capacity is all Said sum of said first remaining capacity of said inverter device;

a third determining unit, configured to determine, according to the determined allocation coefficient, and the reactive power to be compensated total of the to-be-compensated point, the reactive compensation component allocated to each of the inverter devices; and Or determining, according to the determined distribution coefficient, and the total amount of harmonics to be compensated of the point to be compensated, the harmonic compensation component allocated for each of the inverter devices.
The apparatus according to claim 13 or 14, wherein the transmitting module is further configured to send a synchronization time of the power plant controller of the photovoltaic power station system and each of the inverter devices to a corresponding location. Said inverter equipment.
A plant controller comprising the apparatus of any one of claims 13 to 15.
A storage medium, the storage medium including a stored program, wherein The method of any one of claims 1 to 8 is performed while the program is running.
A processor for running a program, wherein the program is executed to perform the method of any one of claims 1 to 8.