CN115882476A - Photovoltaic power distribution network three-phase imbalance management circuit, method, terminal and storage medium - Google Patents
Photovoltaic power distribution network three-phase imbalance management circuit, method, terminal and storage medium Download PDFInfo
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- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B10/00—Integration of renewable energy sources in buildings
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- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
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Abstract
The invention relates to the field of photovoltaic grid-connected regulation, in particular to a photovoltaic power distribution network three-phase imbalance management circuit, a method, a terminal and a storage medium. According to the method and the device for controlling the three-phase imbalance of the photovoltaic power system, the output and the load in the next time period are determined, so that the electric energy of the light load phase can be stored when the output is surplus, the photovoltaic maximum consumption is achieved, and the three-phase imbalance is controlled. When more output is exerted, the interphase electric energy transfer or the energy storage device is selected to release electric energy, the three-phase imbalance is treated, the effect of peak clipping and valley filling is achieved, the capacity of a main power supply is reduced, and the problem of three-phase imbalance caused by photovoltaic is treated.
Description
Technical Field
The invention relates to the field of photovoltaic grid-connected regulation and control, in particular to a photovoltaic power distribution network three-phase imbalance management circuit, method, terminal and storage medium.
Background
Photovoltaic power generation grid connection, distributed photovoltaic power distribution networks and other terms are well known to more and more people. Therefore, there is often a question of: the household photovoltaic grid-connected power station can generate more or less electricity. Because it is difficult to popularize the household photovoltaic power station in the city at present, most households in the city do not have roof resources for photovoltaic power generation, and the popularization of the photovoltaic power station in independent house types or villas in villages and towns is only suitable. Relatively speaking, what is the maximum installed capacity of a 60-square meter roof, if any, is the effective area of 60-square meter roof in each home, which is a very large margin? How much electricity can be generated per hour?
At present, monocrystalline silicon components and polycrystalline silicon components are commonly adopted in household photovoltaic power stations, the specification is generally 36V280W, and the area of a single block is about 1.8 square meters. The photovoltaic module square matrix is connected with different group cluster parallel mode, must select correct daylighting orientation with reasonable inclination during the installation, and certain distance will stagger between every group array moreover to appear stacking upon each other sheltering from when avoiding sunshine to shine. Meanwhile, in order to be convenient to clean and maintain, a passageway needs to be reserved between the photovoltaic square matrixes. Thus, a roof of 60 square meters suggests a reasonable installation of photovoltaic modules of 20 blocks, a installed capacity of 5.6KW, and a total photovoltaic module area of 36 square meters.
The algorithm is a theoretical value obtained by calculation on the premise of ensuring enough installation space of the photovoltaic panel and enough illumination, and actually, the actual output power of most household photovoltaic power stations does not exceed 3.5KW by considering factors such as installation space, conversion efficiency, illumination intensity and the like.
On the other hand, the photovoltaic power generation of the low-voltage distribution network is accessed to the public power grid by two different grid-connected schemes of alternating current single-phase 220V or three-phase 380V. If the grid connection is carried out by single-phase 220V, the power series of the optional grid-connected inverter is generally 3KW and 5KW; if the grid connection is carried out at 380V three-phase, the power series of the optional grid-connected inverter is generally more than 10 KW. In consideration of the resource input of the three-phase grid-connected line which is reconstructed and expanded in reality and the actual output power ratio of the photovoltaic power stations, most household photovoltaic power stations select the alternating current single phase for grid-connected power generation.
When single-phase grid-connected power generation is adopted, three-phase imbalance of a low-voltage distribution area can be caused frequently due to the fluctuation of photovoltaic power generation and the time-space inconsistency of distribution area load distribution. In order to manage three-phase imbalance, the scheme adopted in the prior art is to transfer a part of load through a load transfer switch or limit the output power of a part of photovoltaic power stations when three-phase imbalance occurs. When the load switch is used for transferring the load, the fluctuation of the user side is large, the fluctuation can bring the consequences of restarting and stopping the equipment, and the load switch is used for switching, so that the fluctuation capability of the load switch following the photovoltaic power station is weak, and the response speed is low. However, the mode of limiting the output power of the photovoltaic power station has the phenomenon of energy abandoning, which damages the benefit of the owner of the photovoltaic power station.
Based on the method, a photovoltaic power distribution network three-phase imbalance treatment method needs to be developed and designed.
Disclosure of Invention
The embodiment of the invention provides a photovoltaic power distribution network three-phase imbalance treatment circuit, a photovoltaic power distribution network three-phase imbalance treatment method, a photovoltaic power distribution network three-phase imbalance treatment terminal and a storage medium, and aims to solve the problem that in the prior art, the photovoltaic power distribution network three-phase imbalance fluctuation is strong and difficult to treat.
In a first aspect, an embodiment of the present invention provides a three-phase imbalance management circuit for a photovoltaic power distribution network, including:
the control unit, a three-phase rectifier bridge formed by thyristors, a three-phase inverter bridge formed by switching elements and an isolation transformer;
the three-phase rectifier bridge converts three-phase alternating voltage at the input end into direct voltage and outputs the direct voltage through the output end;
the input end of the three-phase inverter bridge is electrically connected with the output end of the three-phase rectifier bridge, and the output end of the three-phase inverter bridge is electrically connected with the input end of the isolation transformer;
the three-phase inverter bridge inverts the direct-current voltage into alternating-current voltage in a pulse width modulation mode;
the isolation transformer couples the alternating voltage at the input end to the output end;
and the control unit generates a trigger signal indicating the trigger angle of the three-phase rectifier bridge and a pulse width signal indicating the output pulse width of the three-phase inverter bridge according to the received three-phase voltage waveform.
In a possible implementation manner, the photovoltaic power distribution network three-phase imbalance treatment circuit further includes: the filter capacitor is connected with the output end of the three-phase rectifier bridge in parallel;
the primary side of the isolation transformer is in angular connection, and the secondary side of the isolation transformer is in star connection;
the control unit generates a trigger signal indicating the trigger angle of the three-phase rectifier bridge and a pulse width signal indicating the output pulse width of the three-phase inverter bridge according to the received three-phase voltage waveform, and the control unit comprises:
the control unit generates a delay trigger signal for a thyristor corresponding to a phase with a low effective voltage value in the received three-phase voltage waveform;
the control unit generates a pulse width signal for widening a pulse width for the switching element corresponding to the phase with a low effective voltage value in the received three-phase voltage waveform, and the control unit generates a pulse width signal for turning off the switching element corresponding to the phase with a high effective voltage value in the received three-phase voltage waveform.
In a possible implementation manner, the photovoltaic power distribution network three-phase imbalance management circuit further includes: further comprising: the energy storage unit is electrically connected with the output end of the three-phase rectifier bridge and is used for storing electric energy from the three-phase rectifier bridge or outputting the stored electric energy through the three-phase inverter bridge;
the control unit also receives an external indication signal to generate an energy conversion indication signal which indicates the energy storage unit to store energy or output electric energy.
In a second aspect, an embodiment of the present invention provides a photovoltaic power distribution network, where the photovoltaic power distribution network includes an energy storage unit in the first aspect, and a three-phase rectifier bridge input end and an isolation transformer output end of the photovoltaic power distribution network three-phase imbalance management circuit are respectively electrically connected to three-phase lines of the photovoltaic power distribution network.
In a third aspect, an embodiment of the present invention provides a method for treating three-phase imbalance of a photovoltaic power distribution network, where the method is applied to the photovoltaic power distribution network described in the second aspect, and the method for treating three-phase imbalance of the photovoltaic power distribution network includes:
the method comprises the steps of obtaining a plurality of target output data sets and a plurality of target load data sets, wherein the target output data sets comprise output data corresponding to a plurality of time nodes in a current time period, the target output data sets are obtained based on class centers of a plurality of photovoltaic power stations in a photovoltaic power distribution network, the photovoltaic power stations in the photovoltaic power stations have similar output curves, the target load data sets comprise load data corresponding to the time nodes in the current time period, the target load data sets are obtained based on the class centers of a plurality of load classes in the photovoltaic power distribution network, and the loads in the load classes have similar load curves;
determining total output data and total load data of the photovoltaic power distribution network in the next time period based on the target output data sets and the target load data sets, wherein the total output data represents total output of a plurality of photovoltaic power stations in the photovoltaic power distribution network, and the total load data represents total load of a plurality of loads in the photovoltaic power distribution network;
and determining a strategy for carrying out unbalance management on the photovoltaic power distribution network according to the total output data and the total load data.
In one possible implementation manner, the determining, based on the plurality of target output data sets and the plurality of target load data sets, total output data and total load data of the photovoltaic power distribution network in a next time period includes:
for each of the plurality of target contribution data sets and the plurality of target load data sets, performing the steps of:
acquiring a plurality of historical data sets, wherein the historical data sets comprise a plurality of historical data of a class center;
according to the quantity of data in a data set, respectively selecting a plurality of historical data from a plurality of historical data sets to construct a plurality of historical vectors;
arranging a plurality of data in a data set according to a time sequence to construct a data vector;
respectively constructing a unit vector of the data vector and a unit vector of the plurality of history vectors according to the data vector and the plurality of history vectors;
determining a target history vector according to a first formula, a unit vector of the data vector and a unit vector of the plurality of history vectors, wherein the target history vector is a vector with the maximum proximity value obtained by calculation according to the first formula, and the first formula is as follows:
in the formula, neighbor is a proximity value, N is the total number of elements in the data vector, adata (N) is the nth element of the data vector, and Ah () is the nth element of the history vector;
scaling data in a historical data set corresponding to the target vector according to the ratio of the modulus of the data vector to the modulus of the target vector;
and determining total output data or total load data according to the historical data set corresponding to the target vector.
In a possible implementation manner, the determining, according to the total output data and the total load data, a strategy for performing imbalance management on the photovoltaic power distribution network includes:
if the total output data is larger than the total load data, storing the electric energy of the light load phase into an energy storage unit to treat three-phase imbalance;
if the total output data is smaller than the total load data and the output of the main power supply of the photovoltaic power distribution network is lower than the set output of the main power supply, transferring the electric energy of the light load phase to the heavy load phase through a three-phase rectifier bridge and a three-phase inverter bridge to control three-phase imbalance;
and if the total output data is smaller than the total load data and the output of the main power supply of the photovoltaic power distribution network is not lower than the set output of the main power supply, the electric energy of the energy storage unit is output to the heavy load phase through a three-phase inverter bridge so as to control three-phase imbalance.
In a fourth aspect, an embodiment of the present invention provides a photovoltaic power distribution network three-phase imbalance management device, which is used to implement the photovoltaic power distribution network three-phase imbalance management method according to any one possible implementation manner of the third aspect or the third aspect, where the photovoltaic power distribution network three-phase imbalance management device includes:
the system comprises an output and load data acquisition module, a data acquisition module and a data acquisition module, wherein the output and load data acquisition module is used for acquiring a plurality of target output data sets and a plurality of target load data sets, the target output data sets comprise output data corresponding to a plurality of time nodes in the current time period, the target output data sets are acquired based on class centers of a plurality of photovoltaic power stations in a photovoltaic power distribution network, the photovoltaic power stations in the photovoltaic power stations have similar output curves, the target load data sets comprise load data corresponding to the time nodes in the current time period, the target load data sets are acquired based on the class centers of a plurality of load classes in the photovoltaic power distribution network, and a plurality of loads in the load classes have similar load curves;
the output and load prediction module is used for determining total output data and total load data of the photovoltaic power distribution network in the next time period based on the target output data sets and the target load data sets, wherein the total output data represents the total output of a plurality of photovoltaic power stations in the photovoltaic power distribution network, and the total load data represents the total load of a plurality of loads in the photovoltaic power distribution network;
and the number of the first and second groups,
and the three-phase unbalance treatment module is used for determining a strategy for carrying out unbalance treatment on the photovoltaic power distribution network according to the total output data and the total load data.
In a fifth aspect, an embodiment of the present invention provides a terminal, which includes a memory and a processor, where the memory stores a computer program operable on the processor, and the processor executes the computer program to implement the steps of the method according to the first aspect or any possible implementation manner of the first aspect.
In a sixth aspect, the present invention provides a computer-readable storage medium, which stores a computer program, and the computer program, when executed by a processor, implements the steps of the method as described in the first aspect or any one of the possible implementations of the first aspect.
Compared with the prior art, the implementation mode of the invention has the following beneficial effects:
according to the embodiment of the photovoltaic power distribution network three-phase imbalance treatment circuit, the three-phase imbalance caused by photovoltaic output difference and load difference of the photovoltaic power distribution network can be subjected to electric energy transfer at the phases through the power electronic element, so that three-phase imbalance treatment is completed.
The invention relates to an implementation mode of a three-phase imbalance management method for a photovoltaic power distribution network, which comprises the steps of firstly obtaining a plurality of target output data sets and a plurality of target load data sets, wherein the target output data sets comprise output data corresponding to a plurality of time nodes in the current time period, the plurality of target output data sets are obtained based on class centers of a plurality of photovoltaic power stations in the photovoltaic power distribution network, the plurality of photovoltaic power stations in the photovoltaic power stations have similar output curves, the target load data sets comprise load data corresponding to the plurality of time nodes in the current time period, the plurality of target load data sets are obtained based on the class centers of a plurality of load classes in the photovoltaic power distribution network, and a plurality of loads in the load classes have similar load curves; then, based on the target output data sets and the target load data sets, determining total output data and total load data of the photovoltaic power distribution network in the next time period, wherein the total output data represents total output of a plurality of photovoltaic power stations in the photovoltaic power distribution network, and the total load data represents total load of a plurality of loads in the photovoltaic power distribution network; and finally, determining a strategy for treating the unbalance of the photovoltaic power distribution network according to the total output data and the total load data. When the output is more, the interphase electric energy transfer or the energy storage device can be selected to release electric energy, the three-phase imbalance is treated, the effect of peak clipping and valley filling is achieved, the capacity of the main power supply design is reduced, and the problem of three-phase imbalance caused by photovoltaic is treated.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.
Fig. 1 is a schematic diagram of a photovoltaic power distribution network to which a three-phase imbalance management circuit is applied according to an embodiment of the present invention;
fig. 2 is a flow chart of a photovoltaic power distribution network three-phase imbalance management method provided by an embodiment of the invention;
fig. 3 is a functional block diagram of a photovoltaic power distribution network three-phase imbalance management device provided by the embodiment of the invention;
fig. 4 is a functional block diagram of a terminal according to an embodiment of the present invention.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following description is made with reference to the accompanying drawings.
The following is a detailed description of the embodiments of the present invention, which is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.
Fig. 1 is a schematic diagram of a photovoltaic power distribution network to which a three-phase imbalance management circuit is applied according to an embodiment of the present invention.
As shown in fig. 1, a schematic diagram of a photovoltaic power distribution network applied with a three-phase imbalance suppression circuit according to a first aspect of the embodiment of the present invention is shown, and is detailed as follows:
the utility model provides a photovoltaic distribution network unbalanced three phase administers circuit, includes:
the control unit, three-phase rectifier bridge 101 formed by thyristors, three-phase inverter bridge 102 formed by switching elements and isolation transformer 103;
the three-phase rectifier bridge 101 converts three-phase alternating voltage at the input end into direct voltage and outputs the direct voltage through the output end;
the input end of the three-phase inverter bridge 102 is electrically connected with the output end of the three-phase rectifier bridge 101, and the output end of the three-phase inverter bridge 102 is electrically connected with the input end of the isolation transformer 103;
the three-phase inverter bridge 102 inverts the dc voltage into an ac voltage in a pulse width modulation manner;
the isolation transformer 103 couples the alternating voltage at the input end to the output end;
the control unit generates a trigger signal indicating a trigger angle of the three-phase rectifier bridge 101 and a pulse width signal indicating an output pulse width of the three-phase inverter bridge 102 according to the received three-phase voltage waveform.
Illustratively, the photovoltaic power distribution network three-phase unbalance treatment circuit comprises a three-phase rectifier bridge 101, a three-phase inverter bridge 102, an isolation transformer 103 and a control unit for outputting a working signal indicating the three-phase rectifier bridge 101 and outputting a working signal indicating the three-phase inverter bridge 102.
The three-phase rectifier bridge 101 is formed by thyristors, and when the firing angles of the thyristors are controlled, the input-output relationship between the three-phase rectifier bridge 101 and the three-phase line 100 of the distribution network can be controlled, for example, when the firing angles of the thyristors connected to the second phase are controlled to be triggered in a delayed manner, the output of the second phase will be reduced, and at the same time, the output of the corresponding first phase or third phase will be increased.
The three-phase inverter bridge 102 outputs a sine waveform by pulse width modulation, and when the output pulse width of the switching element of the corresponding phase is increased, the effective value of the sine waveform is increased, and when the output pulse width is connected to the corresponding phase through the isolation transformer 103 and output to the corresponding phase, the voltage of the phase is increased accordingly.
That is, by controlling the delay of the firing angle of the thyristors connected to the three phases, the output of one or two of the three phases is controlled to be increased or decreased, and the switching pulse width of the switching element is controlled, thereby adjusting the grid-connected phase voltage of the isolation transformer 103.
According to the embodiment of the invention, through the power electronic element, the three-phase output imbalance caused by the photovoltaic output imbalance and the load imbalance of the photovoltaic distribution network 105 can be transferred among phases, so that the treatment of the three-phase imbalance is completed.
In some embodiments, the photovoltaic distribution network three-phase imbalance management circuit further comprises: the filter capacitor 106 is connected in parallel with the output end of the three-phase rectifier bridge 101;
the primary side of the isolation transformer 103 is connected in an angular manner, and the secondary side of the isolation transformer 103 is connected in a star manner;
the control unit generates a trigger signal indicating a trigger angle of the three-phase rectifier bridge 101 and a pulse width signal indicating an output pulse width of the three-phase inverter bridge 102 according to the received three-phase voltage waveform, and the control unit includes:
the control unit generates a delay trigger signal for a thyristor corresponding to a phase with a low effective voltage value in the received three-phase voltage waveform;
the control unit generates a pulse width signal for widening a pulse width for the switching element corresponding to the phase with a low effective voltage value in the received three-phase voltage waveform, and the control unit generates a pulse width signal for turning off the switching element corresponding to the phase with a high effective voltage value in the received three-phase voltage waveform.
In some embodiments, the photovoltaic distribution network three-phase imbalance management circuit further comprises: further comprising: the energy storage unit 107, the energy storage unit 107 is electrically connected to the output end of the three-phase rectifier bridge 101, and the energy storage unit 107 is configured to store electric energy from the three-phase rectifier bridge 101 or output the stored electric energy through the three-phase inverter bridge 102;
the control unit also receives an external indication signal to generate an energy conversion indication signal indicating the energy storage unit 107 to store energy or output electric energy.
For example, in some application scenarios, the output end of the three-phase rectifier bridge 101 is connected in parallel with the filter capacitor 106, and the primary side of the isolation transformer 103 is connected in an angular manner, and the secondary side of the isolation transformer 103 is connected in a star manner.
In other application scenarios, the energy storage unit 107 is arranged at the output end of the rectifier bridge, for example, a storage battery, when the output of the photovoltaic power generation station 104 is large, the electric energy can be consumed through the storage battery, for example, the electric energy of the light-load phase is stored, so that the problem of unbalanced three phases is solved while photovoltaic consumption is achieved.
Embodiments of the present invention are discussed in detail from a second aspect for photovoltaic absorption and remediation of three-phase imbalance.
Fig. 2 is a flowchart of a photovoltaic power distribution network three-phase imbalance management method provided by the embodiment of the invention.
As shown in fig. 2, it shows an implementation flowchart of a method for treating three-phase imbalance of a photovoltaic power distribution network according to a second aspect of the embodiment of the present invention, which is detailed as follows:
in step 201, a plurality of target output data sets and a plurality of target load data sets are obtained, where a target output data set includes output data corresponding to a plurality of time nodes in a current time period, the target output data sets are obtained based on class centers of a plurality of photovoltaic power stations in a photovoltaic power distribution network, the plurality of photovoltaic power stations in the photovoltaic power stations have similar output curves, a target load data set includes load data corresponding to a plurality of time nodes in the current time period, the target load data sets are obtained based on class centers of a plurality of load classes in the photovoltaic power distribution network, and a plurality of loads in the load classes have similar load curves.
In step 202, total output data and total load data of the photovoltaic power distribution network in a next time period are determined based on the target output data sets and the target load data sets, wherein the total output data represents total output of a plurality of photovoltaic power stations in the photovoltaic power distribution network, and the total load data represents total load of a plurality of loads in the photovoltaic power distribution network.
In some embodiments, the step 202 comprises: for each of the plurality of target contribution data sets and the plurality of target load data sets, performing the steps of:
acquiring a plurality of historical data sets, wherein the historical data sets comprise a plurality of historical data of a class center;
according to the quantity of data in a data set, respectively selecting a plurality of historical data from a plurality of historical data sets to construct a plurality of historical vectors;
arranging a plurality of data in a data set according to a time sequence to construct a data vector;
respectively constructing a unit vector of the data vector and a unit vector of the plurality of history vectors according to the data vector and the plurality of history vectors;
determining a target history vector according to a first formula, a unit vector of the data vector and a unit vector of the plurality of history vectors, wherein the target history vector is a vector with the maximum proximity value obtained by calculation according to the first formula, and the first formula is as follows:
in the formula, neighbor is a neighbor value, N is the total number of elements in the data vector, adata (N) is the nth element of the data vector, and Ah () is the nth element of the history vector;
scaling data in the historical data set corresponding to the target vector according to the ratio of the modulus of the data vector to the modulus of the target vector;
and determining total output data or total load data according to the historical data set corresponding to the target vector.
Illustratively, the embodiment of the invention determines the photovoltaic output data and the load data of the next time period through the photovoltaic output data and the load data of the current time period. Due to the large number of photovoltaic power stations, the output data of several representative photovoltaic power stations are generally selected as the basis for determining the output in the next time period, and the same is true for the load.
One way to determine representative photovoltaic power plants is to cluster the photovoltaic power plants according to the similarity of the output curves of the photovoltaic power plants to obtain a plurality of classes, wherein the clustering algorithm is of various types, such as a K-means clustering algorithm, and the clustering result is to obtain several classes, and the photovoltaic power plants in the classes have similar output curves at the same time. And the data of the photovoltaic power station of the class center is generally taken as photovoltaic output data. The load data processing conditions are the same, loads are classified into several types according to the similarity of load curves through a clustering algorithm, and representative loads are selected to obtain the load data.
The output data and the load data are obtained by intercepting the historical data according to the proximity of the historical data to be used as the photovoltaic output of the next time period.
Specifically, the embodiment of the invention adopts a first formula to determine the proximity to the historical data:
where neighbor is a neighbor value, N is the total number of elements in the data vector, adata (N) is the nth element of the data vector, and Ah () is the nth element of the history vector.
Specifically, the data segment adjacent to the contribution data or the coincidence data of the current time interval in the historical data is found, and the data of the next time interval next to the adjacent data segment is used as the contribution data of the current time interval.
In step 203, a strategy for performing imbalance management on the photovoltaic power distribution network is determined according to the total output data and the total load data.
In some embodiments, the step 203 comprises:
the determining a strategy for carrying out imbalance management on the photovoltaic power distribution network according to the total output data and the total load data comprises the following steps:
if the total output data is larger than the total load data, storing the electric energy of the light load phase into an energy storage unit to treat three-phase imbalance;
if the total output data is smaller than the total load data and the output of the main power supply of the photovoltaic power distribution network is lower than the set output of the main power supply, transferring the electric energy of the light load phase to the heavy load phase through a three-phase rectifier bridge and a three-phase inverter bridge to control three-phase imbalance;
and if the total output data is smaller than the total load data and the output of the main power supply of the photovoltaic power distribution network is not lower than the set output of the main power supply, the electric energy of the energy storage unit is output to the heavy load phase through a three-phase inverter bridge so as to control three-phase imbalance.
Illustratively, for the three-phase imbalance management strategy, if the output in the next time period is determined to be greater than the load, energy storage needs to be performed in advance to avoid photovoltaic waste, and therefore, during energy storage, a phase with light load is selected for energy storage.
If the output in the next time period is less than the load, and the output of the main power supply (such as a distribution transformer) is less at the time and does not reach the set output value (for example, does not reach the set peak value), the voltage of the heavy load phase can be increased by transferring the electric energy from the light load phase to the heavy load phase in the manner described above, so as to realize three-phase balance.
If the output in the next time period is smaller than the load, and the output of the main power supply (such as a distribution transformer) is more at the time and reaches a set output value (such as a set peak value), the electric energy of the energy storage unit can be used for outputting a heavy load phase through the three-phase inverter bridge, so that the voltage of the heavy load phase is improved, and the three-phase balance is realized.
The invention relates to an implementation mode of a three-phase imbalance management method for a photovoltaic power distribution network, which comprises the steps of firstly obtaining a plurality of target output data sets and a plurality of target load data sets, wherein the target output data sets comprise output data corresponding to a plurality of time nodes in the current time period, the plurality of target output data sets are obtained based on class centers of a plurality of photovoltaic power stations in the photovoltaic power distribution network, the plurality of photovoltaic power stations in the photovoltaic power stations have similar output curves, the target load data sets comprise load data corresponding to the plurality of time nodes in the current time period, the plurality of target load data sets are obtained based on the class centers of a plurality of load classes in the photovoltaic power distribution network, and a plurality of loads in the load classes have similar load curves; then, based on the target output data sets and the target load data sets, determining total output data and total load data of the photovoltaic power distribution network in the next time period, wherein the total output data represents total output of a plurality of photovoltaic power stations in the photovoltaic power distribution network, and the total load data represents total load of a plurality of loads in the photovoltaic power distribution network; and finally, determining a strategy for treating the unbalance of the photovoltaic power distribution network according to the total output data and the total load data. When the output is more, the interphase electric energy transfer or the energy storage device can be selected to release electric energy, the three-phase imbalance is treated, the effect of peak clipping and valley filling is achieved, the capacity of the main power supply design is reduced, and the problem of three-phase imbalance caused by photovoltaic is treated.
It should be understood that the sequence numbers of the steps in the above embodiments do not mean the execution sequence, and the execution sequence of each process should be determined by the function and the inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.
The following are embodiments of the apparatus of the invention, and for details not described in detail therein, reference may be made to the corresponding method embodiments described above.
Fig. 3 is a functional block diagram of a photovoltaic power distribution network three-phase imbalance management device according to an embodiment of the present invention, and referring to fig. 3, the photovoltaic power distribution network three-phase imbalance management device 3 includes: the system comprises an output and load data acquisition module 301, an output and load prediction module 302 and a three-phase imbalance management module 303, wherein:
an output and load data obtaining module 301, configured to obtain a plurality of target output data sets and a plurality of target load data sets, where a target output data set includes output data corresponding to a plurality of time nodes at a current time period, the plurality of target output data sets are obtained based on class centers of a plurality of photovoltaic power stations in a photovoltaic power distribution network, the plurality of photovoltaic power stations in the photovoltaic power stations have similar output curves, a target load data set includes load data corresponding to the plurality of time nodes at the current time period, the plurality of target load data sets are obtained based on class centers of a plurality of load classes in the photovoltaic power distribution network, and a plurality of loads in the load classes have similar load curves;
an output and load prediction module 302, configured to determine total output data and total load data of the photovoltaic power distribution network in a next time period based on the target output data sets and the target load data sets, where the total output data represents total output of a plurality of photovoltaic power stations in the photovoltaic power distribution network, and the total load data represents total load of a plurality of loads in the photovoltaic power distribution network;
and the three-phase imbalance management module 303 is configured to determine a strategy for performing imbalance management on the photovoltaic power distribution network according to the total output data and the total load data.
Fig. 4 is a functional block diagram of a terminal according to an embodiment of the present invention. As shown in fig. 4, the terminal 4 of this embodiment includes: a processor 400 and a memory 401, said memory 401 having stored therein a computer program 402 executable on said processor 400. The processor 400 executes the computer program 402 to implement the above-mentioned three-phase imbalance management method and steps of the embodiments of the photovoltaic power distribution network, such as the steps 202 to 203 shown in fig. 2.
Illustratively, the computer program 402 may be partitioned into one or more modules/units, which are stored in the memory 401 and executed by the processor 400 to implement the present invention.
The terminal 4 may be a desktop computer, a notebook, a palm computer, a cloud server, or other computing devices. The terminal 4 may include, but is not limited to, a processor 400, a memory 401. It will be appreciated by those skilled in the art that fig. 4 is only an example of a terminal 4 and does not constitute a limitation of the terminal 4, and that it may comprise more or less components than those shown, or some components may be combined, or different components, for example, the terminal 4 may further comprise input and output devices, network access devices, buses, etc.
The Processor 400 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 401 may be an internal storage unit of the terminal 4, such as a hard disk or a memory of the terminal 4. The memory 401 may also be an external storage device of the terminal 4, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), etc. provided on the terminal 4. Further, the memory 401 may also include both an internal storage unit and an external storage device of the terminal 4. The memory 401 is used for storing the computer program 402 and other programs and data required by the terminal 4. The memory 401 may also be used to temporarily store data that has been output or is to be output.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit, and the integrated unit may be implemented in a form of hardware, or may be implemented in a form of software functional unit. In addition, specific names of the functional units and modules are only used for distinguishing one functional unit from another, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the above embodiments, the description of each embodiment is focused on, and for parts that are not described or illustrated in detail in a certain embodiment, reference may be made to the description of other embodiments.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/terminal and method may be implemented in other manners. For example, the above-described apparatus/terminal embodiments are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method according to the above embodiments may be implemented by a computer program, which may be stored in a computer readable storage medium and used for implementing the steps of the method and apparatus embodiments when executed by a processor. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U.S. disk, removable hard disk, magnetic diskette, optical disk, computer Memory, read-Only Memory (ROM), random Access Memory (RAM), electrical carrier wave signal, telecommunications signal, and software distribution medium, etc.
The above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may be modified or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.
Claims (10)
1. The utility model provides a photovoltaic distribution network unbalanced three phase administers circuit which characterized in that includes:
the control unit, a three-phase rectifier bridge formed by thyristors, a three-phase inverter bridge formed by switching elements and an isolation transformer;
the three-phase rectifier bridge converts three-phase alternating voltage at the input end into direct voltage and outputs the direct voltage through the output end;
the input end of the three-phase inverter bridge is electrically connected with the output end of the three-phase rectifier bridge, and the output end of the three-phase inverter bridge is electrically connected with the input end of the isolation transformer;
the three-phase inverter bridge inverts the direct-current voltage into alternating-current voltage in a pulse width modulation mode;
the isolation transformer couples the alternating voltage at the input end to the output end;
and the control unit generates a trigger signal indicating the trigger angle of the three-phase rectifier bridge and a pulse width signal indicating the output pulse width of the three-phase inverter bridge according to the received three-phase voltage waveform.
2. The photovoltaic distribution network three-phase imbalance management circuit of claim 1, further comprising: the filter capacitor is connected with the output end of the three-phase rectifier bridge in parallel;
the primary side of the isolation transformer is connected in an angular mode, and the secondary side of the isolation transformer is connected in a star mode;
the control unit generates a trigger signal indicating the trigger angle of the three-phase rectifier bridge and a pulse width signal indicating the output pulse width of the three-phase inverter bridge according to the received three-phase voltage waveform, and the control unit comprises:
the control unit generates a delay trigger signal for the thyristor corresponding to the phase with the low effective voltage value in the received three-phase voltage waveform;
the control unit generates a pulse width signal for widening a pulse width for the switching element corresponding to the phase with a low effective voltage value in the received three-phase voltage waveform, and the control unit generates a pulse width signal for turning off the switching element corresponding to the phase with a high effective voltage value in the received three-phase voltage waveform.
3. The three-phase imbalance management circuit for the photovoltaic power distribution network according to any one of claims 1-2, further comprising: the energy storage unit is electrically connected with the output end of the three-phase rectifier bridge and is used for storing electric energy from the three-phase rectifier bridge or outputting the stored electric energy through the three-phase inverter bridge;
the control unit also receives an external indicating signal to generate an energy conversion indicating signal which indicates the energy storage unit to store energy or output electric energy.
4. A photovoltaic power distribution network, characterized in that the photovoltaic power distribution network three-phase imbalance management circuit according to claim 3 is provided, and the three-phase rectifier bridge input end and the isolation transformer output end of the photovoltaic power distribution network three-phase imbalance management circuit are respectively and electrically connected with three-phase lines of the photovoltaic power distribution network.
5. A photovoltaic power distribution network three-phase imbalance management method is applied to the photovoltaic power distribution network according to claim 4, and comprises the following steps:
the method comprises the steps of obtaining a plurality of target output data sets and a plurality of target load data sets, wherein the target output data sets comprise output data corresponding to a plurality of time nodes in a current time period, the target output data sets are obtained based on class centers of a plurality of photovoltaic power stations in a photovoltaic power distribution network, the photovoltaic power stations in the photovoltaic power stations have similar output curves, the target load data sets comprise load data corresponding to the time nodes in the current time period, the target load data sets are obtained based on the class centers of a plurality of load classes in the photovoltaic power distribution network, and the loads in the load classes have similar load curves;
determining total output data and total load data of the photovoltaic power distribution network in the next time period based on the target output data sets and the target load data sets, wherein the total output data represents total output of a plurality of photovoltaic power stations in the photovoltaic power distribution network, and the total load data represents total load of a plurality of loads in the photovoltaic power distribution network;
and determining a strategy for carrying out unbalance management on the photovoltaic power distribution network according to the total output data and the total load data.
6. The method according to claim 5, wherein the determining total output data and total load data of the photovoltaic power distribution network for the next time period based on the target output data sets and the target load data sets comprises:
for each of the plurality of target contribution data sets and the plurality of target load data sets, performing the steps of:
acquiring a plurality of historical data sets, wherein the historical data sets comprise a plurality of historical data of a class center;
according to the quantity of data in a data set, respectively selecting a plurality of historical data from a plurality of historical data sets to construct a plurality of historical vectors;
arranging a plurality of data in a data set according to a time sequence to construct a data vector;
respectively constructing a unit vector of the data vector and a unit vector of the plurality of history vectors according to the data vector and the plurality of history vectors;
determining a target history vector according to a first formula, a unit vector of the data vector and a unit vector of the plurality of history vectors, wherein the target history vector is a vector with the maximum proximity value obtained by calculation according to the first formula, and the first formula is as follows:
wherein neighbor is a neighbor value, N is the total number of elements in the data vector, adata (N) is the nth element of the data vector, and Ahistory (N) is the nth element of the history vector;
scaling data in the historical data set corresponding to the target vector according to the ratio of the modulus of the data vector to the modulus of the target vector;
and determining total output data or total load data according to the historical data set corresponding to the target vector.
7. The method for three-phase imbalance management of a photovoltaic power distribution network according to any one of claims 5 to 6, wherein the determining a strategy for imbalance management of the photovoltaic power distribution network according to the total output data and the total load data includes:
if the total output data is larger than the total load data, storing the electric energy of the light load phase into an energy storage unit to treat three-phase imbalance;
if the total output data is smaller than the total load data and the output of the main power supply of the photovoltaic power distribution network is lower than the set output of the main power supply, transferring the electric energy of the light load phase to the heavy load phase through a three-phase rectifier bridge and a three-phase inverter bridge to control three-phase imbalance;
and if the total output data is smaller than the total load data and the output of the main power supply of the photovoltaic power distribution network is not lower than the set output of the main power supply, the electric energy of the energy storage unit is output to the heavy load phase through a three-phase inverter bridge so as to control three-phase imbalance.
8. A photovoltaic power distribution network three-phase imbalance management device used for realizing the photovoltaic power distribution network three-phase imbalance management method according to any one of claims 5 to 7, wherein the photovoltaic power distribution network three-phase imbalance management device comprises:
the system comprises an output and load data acquisition module, a load analysis module and a load analysis module, wherein the output and load data acquisition module is used for acquiring a plurality of target output data sets and a plurality of target load data sets, the target output data sets comprise output data corresponding to a plurality of time nodes in a current time period, the target output data sets are acquired based on class centers of a plurality of photovoltaic power stations in a photovoltaic power distribution network, the photovoltaic power stations in the photovoltaic power stations have similar output curves, the target load data sets comprise load data corresponding to the time nodes in the current time period, the target load data sets are acquired based on the class centers of a plurality of load classes in the photovoltaic power distribution network, and a plurality of loads in the load classes have similar load curves;
the output and load prediction module is used for determining total output data and total load data of the photovoltaic power distribution network in the next time period based on the target output data sets and the target load data sets, wherein the total output data represents the total output of a plurality of photovoltaic power stations in the photovoltaic power distribution network, and the total load data represents the total load of a plurality of loads in the photovoltaic power distribution network;
and the number of the first and second groups,
and the three-phase unbalance treatment module is used for determining a strategy for carrying out unbalance treatment on the photovoltaic power distribution network according to the total output data and the total load data.
9. A terminal comprising a memory and a processor, the memory having stored therein a computer program operable on the processor, wherein the processor, when executing the computer program, performs the steps of the method according to any of claims 5 to 7.
10. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 5 to 7.
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