KR102272948B1 - Distributed Module-Level Photovoltaic Solar Power Generation Monitoring and Control System using Decentralised Wireless Mesh Network - Google Patents

Abstract

The present invention relates to a distributed module level solar power generation monitoring and control system based on a decentralized wireless mesh network, capable of rapid maintenance, which comprises: a voltage and current detection unit; an arc fault detection unit for detecting a DC arc fault; an on/off switch for opening and closing a power generation output; a control processing unit; a bypass circuit unit including a bypass circuit; and a wireless communication unit having a Bluetooth wireless mesh network.

Description

Distributed Module-Level Photovoltaic Solar Power Generation Monitoring and Control System using Decentralized Wireless Mesh Network

The present invention relates to a distributed module-level solar power generation monitoring and control system based on a centralized wireless mesh network, and more particularly, to a voltage and current detection unit for measuring the voltage and current generated by individual solar module panels, and An arc fault detector for detecting a DC arc fault occurring between the photovoltaic module panel itself or the photovoltaic module panel, and the voltage and current values measured by the voltage detecting section and the current detecting section are less than or exceeding a preset reference value, or the arc fault detecting section An on/off switch that opens and closes the power generation output of a corresponding individual photovoltaic module panel according to occurrence or release of an abnormal condition in which a DC arc fault is detected, and a control processing unit for controlling the on/off switch according to occurrence or release of the abnormal condition And, when the on/off switch is turned off and the power generation output of the individual solar module panel is cut off, a bypass circuit part configured as a bypass circuit to bypass the individual solar module panel, and adjacent individual solar module panels A module-level monitoring and control device comprising a wireless communication unit constituting a Bluetooth wireless mesh network to configure a short-range network or a large-scale long-distance network for relaying messages or to communicate with a gateway device is provided in each individual solar module panel to provide a central control type Based on this distributed wireless mesh network, individual photovoltaic module panels are configured to autonomously detect abnormalities, switch on/off, and bypass, so that photovoltaic power generation continues with normal efficiency and operation. It relates to a distributed module-level solar power generation monitoring and control system based on a wireless mesh network.

2. Description of the Related Art In general, a photovoltaic power generation system is a power generation system that converts sunlight into direct current electricity to produce current, and uses solar energy to produce electricity by expanding a photovoltaic module panel to which several solar cells are attached on a large scale.

Such a photovoltaic system is typically, as shown in [Fig. 1], a plurality of photovoltaic module panels (Panel) (1) are connected in series and in parallel to form a photovoltaic array (Array) (2), connection It is configured to include a Junction box (3), an inverter (4), at this time, as shown in [Fig. 2], the solar module panel (Panel) (1) is a plurality of solar cells Consisting of cells, the solar module panels are connected in series in plurality to constitute a solar string, and the solar strings are connected in parallel in plurality An array (2) is constituted.

Here, the solar module panel (Panel) (1) generates DC power from sunlight and transmits it to an inverter (4) through a junction box (3), and the inverter (4) It serves to convert the DC power generated through each solar module panel 1 into AC power to supply the grid load.

The power generated from the photovoltaic module panel 1 of the photovoltaic power generation system generates DC DC power. In order to generate commercial AC power in the inverter 3, it is usually at a level in a predetermined range (eg, DC 400 ~ 700V). DC input voltage of must be input to inverter (3).

However, at sunrise or sunset, the output voltage of the solar module panels 1 connected in series is lowered because the amount of sunlight is relatively low, so at this time, the DC input voltage input to the inverter 3 is low and commercial AC Since normal power generation is not performed, there is a problem in that power generation efficiency is lowered.

In addition, in a state in which each string connected in series is connected in parallel, the surface of each solar module panel 1 constituting any one string or a plurality of strings is contaminated or shading occurs Or, when an electrical fault such as a short circuit or an arc fault occurs in the solar module panel 1, the voltage of the corresponding string drops and power generation efficiency decreases or a fire occurs, etc. There is a problem in that actual power production is impossible. .

In order to solve the above problems, Korean Patent No. 10-1465764 (registration date November 20, 2014) discloses that in a solar power generation system having an external environment adaptive solar module monitoring function, Diagnosis unit for performing diagnosis on each of at least one solar module - The diagnosis unit determines whether a voltage value of a solar module to be diagnosed included in the solar array is less than or equal to a first reference value, When it is determined that the voltage value of the module is equal to or less than the first reference value, it is determined whether the voltage value of the solar module to be diagnosed is less than or equal to the overall average value of the solar array, and the voltage value of the solar module to be diagnosed is the sunlight If it is determined that it is less than or equal to the average value of the entire array, it is determined that there is an abnormality in the solar module to be diagnosed, and when it is determined that the voltage value of the solar module to be diagnosed exceeds the average value of the entire solar array, the solar module to be diagnosed It is determined that this is normal, and the first reference value is the following equation, first reference value = basic reference voltage value * (1 + voltage increase rate according to increase or decrease of temperature) * (1 + voltage increase rate according to increase or decrease of illuminance), in The basic reference voltage value is the output voltage of the solar module in the reference state, and when the voltage increase rate according to the increase or decrease of the illuminance is calculated, by the illuminance sensor attached to each of the four corners of the solar array It is calculated using the maximum illuminance value among the detected illuminance values, and the temperature of the photovoltaic module for determining the increase or decrease of the temperature and the illuminance of the photovoltaic module for determining the increase or decrease of the illuminance are the voltage of the solar module to be diagnosed A photovoltaic system characterized in that it is sampled with a value has been developed.

In addition, Korean Patent Application Laid-Open No. 10-2020-0113877 (published on October 07, 2020) discloses a solar power generation system 100 including a solar cell array unit 110 , a connection board 140 and an inverter 150 . In the above, the solar cell array unit 110 includes a plurality of solar cell module strings 120, wherein a plurality of solar cell modules 114 in which a plurality of cells 112 are connected in series are connected in series with each other, Each of the plurality of solar cell module strings 120 is connected in parallel to each other, and the photovoltaic power generation system 100 is provided between the output terminal of each of the solar cell module strings 120 and the connection panel 140 to each A first voltage detection unit 160 for detecting a voltage output from the solar cell module string 120 of the; Each solar cell module 131 (hereinafter referred to as an auxiliary solar cell module 131) constituting at least one string 130 (hereinafter referred to as an auxiliary string 130) among the solar cell module strings 120 is referred to as an auxiliary solar cell module 131. ) provided at the output terminal of the second voltage detection unit 132 for detecting the voltage output from each of the auxiliary solar cell module 131; The auxiliary string 130 is provided between a first voltage detection unit 133 (hereinafter referred to as an auxiliary first voltage detection unit 133) for detecting a voltage output from the auxiliary string 130 and a connection panel 140 . and a first switch unit 134 for turning on/off the connection of the connection panel 140; a second switch unit 135 for turning on/off the series connection between the auxiliary solar cell modules 131; The auxiliary solar cell module 131 to selectively connect each of the auxiliary solar cell modules 131 in series to each of the remaining strings 125 (hereinafter, referred to as the main string 125) excluding the auxiliary string 130 . a third switch unit 136 for turning on/off the series connection of each and the main string 125; and the first switch unit 134 , the second switch unit 135 , and the third switch unit 136 according to the voltages detected by the first voltage detection unit 160 and the second voltage detection unit 132 . A photovoltaic system is known, comprising a control unit 170 for controlling the

However, since the Korean Patent No. 10-1465764 and Korean Patent Publication No. 10-2020-0113877 patents monitor the total generated voltage and current of the solar cell array unit or monitor the generated voltage and current of each solar cell string, many When an abnormality occurs in any one of the solar cell modules of , it is not easy to determine which module has an abnormal state, so there is a problem that maintenance of the solar cell array unit takes a lot of time and money.

In order to solve the above problems, Korean Patent Registration No. 10-1266346 (registration date May 15, 2013) discloses a plurality of solar cell modules for generating electricity by collecting energy from sunlight, and a voltage applied to the solar cell module. In the photovoltaic power generation system comprising a power sensor unit for measuring overcurrent, a communication unit for transmitting data from the power sensor unit, and monitoring a power generation state through a data collector for collecting data from the communication unit, the solar cell module includes: Recording the voltage of individual solar cell modules in the state of exceeding the operating reference power considered to have reached a stable power generation process, calculating an error rate for the average of the voltages, and determining that the voltage is abnormal if the reference error rate is exceeded, Recording the current of individual solar cell modules, calculating the error rate for the average of the currents, and determining that the current is abnormal when the reference error rate is exceeded. A solar cell module failure determination method including the step of determining is known.

In addition, Korean Patent No. 10-1409774 (registration date June 13, 2014) in a solar cell panel monitoring device for individually monitoring the state of each of a plurality of solar cell panels applied to a photovoltaic power generation facility, the solar cell a voltage detection unit and a current detection unit respectively detecting a current and a voltage output from the panel; a controller configured to calculate the current and voltage values detected by the voltage detector and the current detector; and an RF wireless communication unit for wirelessly transmitting data including the magnitudes of current and voltage calculated by the control unit, wherein the solar cell panel monitoring device has a sequence number for identification, and the RF wireless communication unit uses a bridge protocol to receive the data transmitted from the RF wireless communication unit of the other solar cell panel monitoring device and re-transmit the data received from the RF wireless communication unit of the other solar cell panel monitoring device, but to the data including the magnitude of the current and voltage Combines and transmits the sequence number of the included solar cell panel monitoring device, and after receiving the combined data with a sequence number one higher or one lower than the sequence number of the included solar cell panel monitoring device, the included solar cell The RF wireless communication unit included in the solar cell panel monitoring device having the lowest sequence number or the highest sequence number is combined and transmitted again by combining the sequence numbers of the cell panel monitoring devices. Connection for collecting data from the plurality of solar cell panel monitoring devices In half, an individual solar cell panel monitoring device applied to a solar power facility monitoring system, characterized in that it transmits data received from another solar cell panel monitoring device, is known.

However, the solar cell module failure determination of the photovoltaic power generation system for monitoring the power generation state of the Korea Patent No. 10-1266346 and the individual solar cell panel monitoring device of the Korea Patent No. 10-1409774 are the failures or voltages of each solar cell module. Since the data is transmitted by judging an abnormality, in order to repair or replace the solar cell module in which the failure or abnormality has occurred, there is a fatal problem in that the entire series-connected string to which the failure or abnormality occurs is impossible to generate power.

In order to solve the above conventional problems, Korean Patent Registration No. 10-1526271 (registration date, June 01, 2015) discloses an array in which at least one solar power module is connected in series; a data acquisition unit for acquiring an abnormality detection signal from the array; a failure array display unit for processing the abnormal detection signal acquired from the array to display the array in which a failure has occurred to the user; And when an abnormality or failure of the solar power module is detected and displayed, and when an abnormality or failure occurs in the photovoltaic module, the electricity flowing from the solar power module of the previous stage connected in series is bypassed. Including, but the module monitoring and bypass unit, the module monitoring and bypass unit, when an abnormality or failure occurs in the photovoltaic module of the previous stage, a bypass diode for bypassing the faulty solar power module and allowing electricity flowing from the photovoltaic module to flow; a relay that excites a solenoid by electricity flowing through the bypass diode and allows electricity to flow through the solenoid to a next stage solar power module; and a light emitting device connected in parallel to the bypass diode and the relay and lit by electricity flowing by bypassing the failed solar power module, wherein the bypass diode and the solenoid of the relay are connected in series, and the The relay is implemented so that an abnormality detection signal flows through the B contact, the B contact is normally in an on state, and is a contact that is switched to an off state when the solenoid is excited, and the relay, when electricity flows through the bypass diode, Health diagnosis of a solar power module, characterized in that by exciting the solenoid of the relay connected in series to the bypass diode to turn off the B contact to which the abnormality detection signal line is connected to block the abnormality detection signal from flowing The device is known.

In addition, in Korea Patent Registration 10-1743908 (registration date May 31, 2017), in the PV failure and defective module bypass system of the photovoltaic device, a photovoltaic device composed of a plurality of PV modules connected in series ; a bypass module installed in each of the PV modules and configured with a bypass circuit bypassing the PV module; A power sensor that is installed in each of the PV modules, a power sensor that measures the power of the PV module, a temperature sensor that measures the temperature generated by the PV module, and a TEV that detects a transient grounding voltage (TEV) generated in the PV module a sensor module composed of a sensor; And, receiving the detection value from the sensor module, calculating the power of the PV module with the detection value of the power, obtaining the probability distribution of the detected power, temperature, and transient ground voltage, power, temperature, and transient If the detected value of the ground voltage falls within a predetermined range in the probability distribution, a command is transmitted to the bypass module to bypass and exclude the bypass module, and the detected power value is determined in the probability distribution of the electric power. and a control device that bypasses when the range is below the range, and bypasses when the detected values of the temperature and the transient ground voltage are above a predetermined range, wherein the control device includes an average value and standard of power, temperature, and TEV voltage of all PV modules The deviation is obtained, the probability density function according to a normal distribution is obtained using the average value and the standard deviation, and the failure and defect ranges having a predetermined value or less in the normal distribution curve expressed by the probability density function are obtained, and the failure and The PV module detected by the power, temperature, and TEV voltage entering the defective range is determined as a defective or defective module, and the control device determines that the power Pi of the PV module enters the failure and failure range, and the power Pi of the PV module is the average value of If it is less than half mp/2, the PV module is judged as faulty or defective, the temperature Ti or TEV voltage Ui of the PV module falls within the above fault and fault range, and the temperature Ti or TEV voltage Ui of the PV module is half of the average value If it is less than mt/2 or half mu/2 of the average value, the PV module is determined to be faulty or defective, and the control device determines that the PV module power Pi, temperature Ti, and TEV voltage Ui satisfy the following Equation 1, respectively. A PV failure and defective module bypass system of a photovoltaic device, characterized in that it is determined to be within a defective range, is known.

[Formula 1]

However, mp, mt, and mu are the average values of the power, temperature, and TEV voltage of all PV modules, respectively, σp, σt, and σu are the standard deviations of the power, temperature, and TEV voltage of all PV modules, respectively, and k is greater than 0 constant.

In addition, Korean Patent Registration No. 10-1958941 (registration date March 11, 2019) discloses that a plurality of photovoltaic modules that generate photovoltaic power are connected in series to photovoltaic modules arranged in at least two or more rows and columns; node control units for measuring voltage, current, and power data produced from the solar modules, respectively, and switching off and switching off the connected solar module when the measured data falls short of control-set current, voltage, and power control data; a gateway unit receiving voltage, current, and power measurement data measured from photovoltaic modules from the node controllers, parsing the measurement data, and storing the measurement data; a real-time control module that receives the parsed data from the gateway, processes classification, collation, and analysis, stores it in a database, and transmits a control command for setting control data for controlling node controllers to the gateway unit; And the real-time control module is connected to the Internet or communication network to monitor the photovoltaic power generation device and data including the photovoltaic module, learn the data transmitted from the real-time control module based on machine learning, and to control the photovoltaic power generation A machine learning server that extracts functional data to perform modeling and provides control service data according to the modeling result to a real-time control module, wherein the machine learning server includes: an interface unit for transmitting and receiving data in real time from the machine learning server; a monitoring unit for monitoring by analyzing, classifying, collating, and converting photovoltaic data transmitted from a photovoltaic power generation device including a photovoltaic module, a node control unit, a gateway unit, and a real-time control module according to characteristics; a determination unit for determining whether machine learning processing is necessary according to the profile information of the integrated processed data transmitted from the monitoring unit; a learning module for performing new learning on data requiring new learning according to the determination unit; a modeling unit extracting data using the learned result and performing modeling; a learning database for storing the learning result and the modeling performance result; a control unit that fetches modeling data for solar power generation control from the learning database and transmits it to a service unit for solar power generation control together with data not determined by learning by the determining unit; a service unit for defining solar control service data by selecting from among the reference models transmitted from the control unit and transmitting it to a real-time control module through an interface; And a machine learning-based photovoltaic power generation control system is known, comprising a service management module for managing by deleting or adding and updating the modeling data list transmitted to the service unit.

However, the health diagnosis device of the solar power generation module of the Korean Patent No. 10-1526271, the PV failure and defective module bypass system of the solar power generation device of the Korean Patent No. 10-1743908, and the machine learning of the Korean Patent No. 10-1958941 Although the solar power generation control system has a stable power generation effect by monitoring individual photovoltaic modules and bypassing the photovoltaic module that has an abnormality, both transmit the abnormal data of each photovoltaic module to the centralized control device and Since it bypasses with an operation algorithm by , there is an advantage that there is no significant effect on the entire solar module string power generation, but the control device is centrally managed and controlled as an integrated system and the control is processed by a complex control algorithm. There was a problem such as excessive, and when an abnormality occurred in the control device, there was a problem that an abnormality of an individual solar module could not be detected. Therefore, the structure by distributed control rather than centralized control is simple and installation cost is reduced. There is an urgent need to develop a distributed monitoring and control system that applies anomaly detection blocking and bypass of individual solar modules.

[Patent Document 001] Korean Patent Registration 10-1465764 (Registration Date: November 20, 2014) [Patent Document 002] Korean Patent Publication No. 10-2020-0113877 (published on October 07, 2020) [Patent Document 003] Korean Patent 10-1266346 (Registration Date: May 15, 2013) [Patent Document 004] Korean Patent Registration 10-1409774 (Registration Date June 13, 2014) [Patent Document 005] Korean Patent Registration 10-1526271 (Registration Date: June 01, 2015) [Patent Document 006] Korean Patent 10-1743908 (Registration Date: May 31, 2017) [Patent Document 007] Korean Patent No. 10-1958941 (Registration Date March 11, 2019)

In order to solve the above conventional problems, the present invention provides a voltage detection unit and a current detection unit for measuring the voltage and current generated in an individual solar module panel, and a DC arc generated between the individual solar module panel itself or the solar module panel. An arc fault detection unit that detects a fault, and the voltage and current values measured by the voltage detection unit and the current detection unit are less than or exceeding preset reference values, or a DC arc fault is detected from the arc fault detection unit. An on/off switch that opens and closes the power generation output of a solar module panel, a control processing unit that controls the on/off switch according to the occurrence or release of the abnormal condition, and the on/off switch of the individual solar module panel When the power generation output is cut off, a bypass circuit part composed of a bypass circuit to bypass the individual solar module panel, and a short-range network or large-scale long-distance network that relays messages between adjacent individual solar module panels, or with a gateway device In order to communicate, a module-level monitoring and control device comprising a wireless communication unit constituting a Bluetooth wireless mesh network is provided in each individual solar module panel, so that individual solar module panels are installed based on a distributed wireless mesh network rather than a central control type. A decentralized, wireless mesh network-based distributed module-level solar power generation monitoring and control system configured to autonomously detect abnormalities, switch on/off, and bypass the photovoltaic power generation to ensure normal efficiency and operation. Make what you provide a challenge to solve.

In order to solve the above problems, the present invention provides a voltage detection unit and a current detection unit for measuring the voltage and current generated by an individual solar module panel, and a DC arc fault occurring between the individual solar module panel itself or the solar module panel. In accordance with the occurrence or cancellation of an abnormal condition in which the voltage and current values measured by the arc fault detection unit and the voltage detection unit and the current detection unit are less than or exceeding preset reference values, or a DC arc fault is detected from the arc fault detection unit, the individual sunlight An on/off switch for opening and closing the power generation output of the module panel, a control processing unit for controlling the on/off switch according to the occurrence or release of the abnormal condition, and the power generation output of an individual solar module panel when the on/off switch is turned off A bypass circuit part configured as a bypass circuit to bypass the respective individual solar module panels when this is blocked, and a short-range network or large-scale long-distance network that relays messages between adjacent individual solar module panels or communicates with a gateway device To this end, a distributed module level solar power generation monitoring and control system based on a centralized wireless mesh network in which a module level monitoring and control device comprising a wireless communication unit constituting a Bluetooth wireless mesh network is provided in each individual solar module panel. do it as a solution.

The control processing unit applies an emergency stop or operation restart control command to the on/off switch and the bypass circuit to open and close the on/off switch and switch the bypass circuit according to the occurrence or release of the abnormal condition. as a means of solving the problem.

When the occurrence of the abnormal condition is released, the control processing unit applies a control command to resume operation after a predetermined period of time to control the operation as a means of solving the problem.

The arc fault detection unit extracts a fundamental component and a harmonic component by Fast Fourier Transform (FFT) on the DC current detected by the current detection unit, and the ratio of a specific harmonic component is greater than or equal to a preset ratio compared to the extracted fundamental component In the case of an arc fault, the Fast Fourier Transform (FFT) and the arc fault detection algorithm are performed by the control processing unit to cut off the on/off switch as a means of solving the problem.

The bypass circuit unit includes a bypass circuit connected in series with an adjacent individual photovoltaic module panel, and a MOSFET or IGBT switch for operating the bypass circuit switching, wherein the MOSFET or IGBT switch operates by itself by energizing a diode, or The means of solving the problem is to operate according to the emergency stop or operation restart control command applied from the control processing unit.

The control processing unit and the wireless communication unit use a Bluetooth wireless mesh between individual solar module panels by a distributed control protocol that relays messages of voltage and current measurement data or arc fault detection data of individual solar module panels to adjacent individual solar module panels. Establishing a network is a means of solving the problem.

The control processing unit and the wireless communication unit assign a group address of a string or array to which the respective individual solar module panels are connected, and transmit an emergency stop or operation restart control command to the group address to autonomously control individual strings or arrays. as a means of solving the problem.

The decentralized wireless mesh network-based distributed module-level solar power generation monitoring and control system of the present invention includes a voltage detection unit and a current detection unit that measure the voltage and current generated by an individual solar module panel, and the individual solar module panel itself or An arc fault detection unit that detects a DC arc fault occurring between the solar module panels, and the voltage and current values measured by the voltage detection unit and the current detection unit are less than or exceeding preset reference values, or a DC arc fault is detected from the arc fault detection unit An on/off switch that opens and closes the power generation output of a corresponding individual photovoltaic module panel according to the occurrence or release of an abnormal condition, and a control processing unit for controlling the on/off switch according to the occurrence or release of the abnormal condition, and the on/off A short-distance network that relays messages between a bypass circuit unit composed of a bypass circuit to bypass the individual photovoltaic module panel when the power generation output of an individual photovoltaic module panel is cut off because the switch is turned off, and a message between adjacent individual photovoltaic module panels Alternatively, a module-level monitoring and control device comprising a wireless communication unit constituting a Bluetooth wireless mesh network to configure a large-scale long-distance network or to communicate with a gateway device is provided in each individual solar module panel, so that a distributed wireless mesh rather than a central control type is provided. Based on the network, individual solar module panels are configured to autonomously detect abnormalities, switch on/off, and bypass individual PV module panels to identify faulty modules through monitoring of individual PV module panels, enabling rapid maintenance and arc fault It has an excellent effect of preventing fire caused by arcs by shutting off self-output through centralized autonomous control in emergency situations such as and ground faults and preventing electric shock accidents of on-site maintenance personnel due to short circuits.

1 is a schematic diagram of a conventional general solar power generation system;
2 is a conventional general photovoltaic module panel, string, array configuration diagram
3 is an overall configuration diagram of an abnormal detection, on/off switching and bypass autonomous control system of an individual solar module panel of the present invention;
4 is a schematic diagram of the operation of an autonomous control system for abnormal detection, on/off switching and bypass of individual solar module panels of the present invention
5 is a bypass circuit diagram of an abnormal detection, on/off switching and bypass autonomous control system of an individual solar module panel of the present invention;
6 is a wireless communication configuration diagram of an individual solar module panel of the present invention for abnormal detection, on/off switching and bypass autonomous control system

The present invention provides a voltage detection unit and a current detection unit for measuring the voltage and current generated by an individual solar module panel, and an arc fault detection unit for detecting a DC arc fault occurring between the individual solar module panel itself or the solar module panel; , In accordance with the occurrence or cancellation of an abnormal condition in which the voltage and current values measured by the voltage detection unit and the current detection unit are less than or exceeding preset reference values, or a DC arc fault is detected from the arc fault detection unit, the power generation output of the individual solar module panel An on/off switch that opens and closes, a control processing unit that controls the on/off switch according to occurrence or release of the abnormal condition, and a corresponding individual when the on/off switch is turned off and the power generation output of an individual solar module panel is blocked A bypass circuit part composed of a bypass circuit to bypass the solar module panel, and a short-range network or a large-scale long-distance network that relays messages between adjacent individual solar module panels, or a Bluetooth wireless mesh network to communicate with a gateway device It features a technology configuration of a distributed module level solar power generation monitoring and control system based on a centralized wireless mesh network in which a module level monitoring and control device configured including a constituting wireless communication unit is provided on each individual solar module panel.

The control processing unit applies an emergency stop or operation restart control command to the on/off switch and the bypass circuit to open and close the on/off switch and switch the bypass circuit according to the occurrence or release of the abnormal condition. It is characterized by the technical composition.

The control processing unit is characterized in that when the occurrence of the abnormal condition is released, after a predetermined period of time, the control processing unit applies an operation restart control command to control the operation.

The arc fault detection unit extracts a fundamental component and a harmonic component by Fast Fourier Transform (FFT) on the DC current detected by the current detection unit, and the ratio of a specific harmonic component is greater than or equal to a preset ratio compared to the extracted fundamental component The technical configuration is characterized in that the Fast Fourier Transform (FFT) and the arc fault detection algorithm are performed by the control processing unit so as to detect an arc fault and cut off the on/off switch.

The bypass circuit unit includes a bypass circuit connected in series with an adjacent individual photovoltaic module panel, and a MOSFET or IGBT switch for operating the bypass circuit switching, wherein the MOSFET or IGBT switch operates by itself by energizing a diode, or It is characterized in that it is operated according to an emergency stop or operation restart control command applied from the control processing unit.

The control processing unit and the wireless communication unit use a Bluetooth wireless mesh between individual solar module panels by a distributed control protocol that relays messages of voltage and current measurement data or arc fault detection data of individual solar module panels to adjacent individual solar module panels. The configuration of the network is characterized by the technical configuration.

The control processing unit and the wireless communication unit assign a group address of a string or array to which the respective individual solar module panels are connected, and transmit an emergency stop or operation restart control command to the group address to autonomously control individual strings or arrays. It is characterized by the technical composition.

Hereinafter, embodiments and/or drawings of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms, and is not limited to the embodiments and/or drawings described herein.

First, referring to [Fig. 3] to [Fig. 4], the decentralized wireless mesh network-based distributed module level solar power generation monitoring and control system of the present invention, the voltage generated by the individual solar module panel (1) and a voltage detection unit 101 and a current detection unit 102 for measuring current, and an arc fault detection unit 103 for detecting a DC arc fault occurring between the individual solar module panel 1 itself or the solar module panel 1 . ) and the voltage and current values measured by the voltage detection unit 101 and the current detection unit 102 are less than or exceeding the preset reference values, or an abnormal condition in which a DC arc fault is detected from the arc fault detection unit 103. An on/off switch 107 that opens and closes the power generation output of the individual solar module panel 1 according to each other, and a control processing unit 104 that controls the on/off switch 107 according to the occurrence or release of the abnormal condition; , When the on/off switch 107 is turned off and the power generation output of the individual photovoltaic module panel 10 is blocked, the bypass circuit unit configured as a bypass circuit to bypass the individual photovoltaic module panel 1 ( 106) and a wireless communication unit 105 that configures a short-range network or a large-scale long-distance network that relays messages between adjacent individual solar module panels 1 or a Bluetooth wireless mesh network to communicate with a gateway device. Module level monitoring and control device 100 is provided in each individual solar module panel (1) is configured.

Here, the voltage detection unit 101 and the current detection unit 102 measure and collect the voltage and current input from the individual solar module panel 10 and transmit the measured voltage and current data to the control processing unit 104 . send

In addition, the arc fault detection unit 103 extracts the fundamental and harmonic components by Fast Fourier Transform (FFT) on the DC current detected by the current detection unit 102, and the ratio of the specific harmonic component is extracted. The Fast Fourier Transform (FFT) and the arc fault detection algorithm are performed by the control processing unit to detect an arc fault when the ratio is greater than or equal to a preset ratio compared to the fundamental component and block the on/off switch

That is, since the waveform of the DC current in the steady state corresponds to sinusoidal symmetry, only a very small harmonic component is included in the analysis based on the fast Fourier transform. However, when an arc failure occurs, the waveform of the DC current has a different shape for every cycle, so that the magnitude of the harmonic component may increase in the analysis based on the fast Fourier transform.

Accordingly, the arc fault detection unit 103 operates to detect an arc failure by measuring a change in a harmonic component of a specific order, and the arc detection method based on such a harmonic component change is easier than the arc failure detection method in the time domain. arcs can be detected.

At this time, the Fast Fourier Transform (FFT) is a mathematical technique of decomposition of a signal into components of a frequency, that is, a function related to the frequency when a function (signal) with respect to time is Fourier transformed. To generate , these programs or algorithms are already well-known and detailed description will be omitted.

Also, optionally, the DC current detected by the current detector 102 may be input to the FFT process through an analog-to-digital converter (ADC) and various filters, that is, an analog-to-digital converter. Various filters such as finite impulse response (FIR) and infinite impulse response (IIR) can be applied to the current signal measured by an analog-to-digital converter (ADC), where the FIR filter is generally used to remove noise components. It is used to design a moving average filter for , and an IIR filter is used to design a bandpass filter.

As described above, for the signal filtered through the filter, the frequency component is calculated using the fast Fourier transform, the total energy is calculated using the calculated frequency magnitude component, and the arc is detected using the calculated energy magnitude. can

Next, the bypass circuit unit 106 includes a bypass circuit 106-1 connected in series with an adjacent individual solar module panel 1, and a MOSFET or IGBT switch 106- that operates the bypass circuit switching. 2), but the MOSFET or IGBT switch 106-2 is configured to operate by itself by energizing a diode or to be operated by an emergency stop or operation restart control command applied from the control processing unit 104.

That is, the bypass circuit unit 106 is a circuit provided to correspond to the individual photovoltaic module panel 1 as shown in [Fig. 5], and the individual photovoltaic module panel 1 and the individual adjacent to each other It is a circuit for directly connecting or bypassing the solar module panel (1) in series.

The bypass circuit unit 106 may be controlled by the control processing unit to primarily implement a bypass operation without the intervention of the control processing unit (energizing the MOSFET body diode) and reduce the diode forward voltage drop.

That is, [Fig. 5(A)] is a circuit diagram in a normal state (blue solid line open normal circuit, red dotted line bypass circuit cutoff), when there is no abnormal occurrence of individual solar module panel 1, [Fig. 5(B) )] is a circuit diagram in which the on/off switch is blocked and the bypass circuit is operated simultaneously by the emergency stop command applied from the control processing unit 104 when an abnormality occurs in the individual solar module panel 1 (the red dotted line is the normal circuit blocking, blue solid line bypass circuit open).

In particular, the bypass circuit unit 106 operates by itself to selectively control direct connection or bypass connection. Optionally, the control is operated by the MOSFET or IGBT switch 106-2 in response to an emergency stop or operation restart control command applied from the control processing unit 104 .

In addition, the control processing unit 104 determines that the voltage and current values measured by the voltage detection unit 101 and the current detection unit 102 are less than or exceeding a preset reference value, or a DC arc fault is detected from the arc fault detection unit 103. The on/off switch 107 opens and closes the on/off switch 107 that opens and closes the power generation output of the respective solar module panel 1 according to the occurrence or release of an abnormal condition and switches the bypass circuit unit 106 and by applying an emergency stop or operation restart control command to the bypass circuit unit 106 to control the operation.

At this time, it is preferable that the control processing unit 104 controls the operation by applying a control command to resume operation after a certain period of time when the occurrence of the abnormal condition is released.

In addition, as shown in [Fig. 6], the control processing unit 104 and the wireless communication unit 105 transmit the voltage and current measurement data or arc fault detection data of the individual solar module panel 1 to the adjacent individual sunlight. A Bluetooth wireless mesh network between individual solar module panels is configured by a distributed control protocol that relays messages to the module panels.

In particular, the control processing unit 104 and the wireless communication unit 105 allocate a group address of a string or array to which the respective individual solar module panel 1 is connected and depend, and an emergency stop or operation restart control command to the group address. to autonomously control individual strings or arrays.

That is, the control processing unit 104 transmits an emergency stop or operation restart control command to the group address of the subordinate string or array through the wireless communication unit 105 according to the occurrence or release of an abnormal condition, so that detection through distributed abnormal detection Increase accuracy, remove fundamental risk factors by opening and closing the output at the panel level rather than string or array when detecting abnormalities, improve reliability by eliminating single point of failure (ie central controller) through decentralized and distributed autonomous control; By applying a mesh network, a control message can be transmitted in a multi-path manner and resiliency can be improved through this.

In addition, since it is controlled by distributed autonomous control that transmits an emergency stop or operation restart control command to the group address of the string or array as described above, there is a very innovative effect that can be controlled without a separate gateway or Internet-based communication. .

In particular, in the present invention, the module-level monitoring and control device can transmit monitoring data such as voltage, current, power, amount of power, operation status, etc. through a mesh network, and the mesh network is a part of or an extension of the underlying protocol, and the packet delivery priority over the network It implements a quality-of-service (QoS) function that guarantees

In addition, the emergency stop command is delivered with a very high priority in QoS, and the monitoring data is delivered with a low priority, so that the emergency stop command is always delivered with priority over the monitoring data on the mesh network.

At this time, if the network bandwidth is insufficient, the monitoring data message may be dropped (ignored) and not delivered to deliver the emergency stop command.

The above description is merely illustrative of the technical idea of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Accordingly, the embodiments and/or drawings disclosed in the present invention are for explanation rather than limiting the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments and/or drawings. . The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

1: Individual solar module panel 100: Module level monitoring and control device
101: voltage detection unit 102: current detection unit
103: arc fault detection unit 104: control processing unit
105: wireless communication unit 106: bypass circuit unit
107: on/off switch

Claims (7)

a voltage detection unit and a current detection unit for measuring the voltage and current generated by individual solar module panels; an arc fault detection unit for detecting a DC arc fault occurring between individual photovoltaic module panels or between photovoltaic module panels; The voltage and current values measured by the voltage detection unit and the current detection unit are less than or exceeding the preset reference values, or the generation output of the individual solar module panel is opened or closed according to the occurrence or cancellation of an abnormal condition in which a DC arc fault is detected from the arc fault detection unit an on/off switch to; a control processing unit for controlling the on/off switch according to occurrence or release of the abnormal condition; a bypass circuit unit configured as a bypass circuit to bypass the individual solar module panel when the on/off switch is turned off and the power generation output of the individual solar module panel is blocked; A module-level monitoring and control device comprising a; a wireless communication unit configuring a Bluetooth wireless mesh network to configure a short-range network or a large-scale long-distance network that relays messages between adjacent individual solar module panels is provided on each individual solar module panel As a decentralized wireless mesh network-based distributed module level solar power generation monitoring and control system,
The bypass circuit unit includes a bypass circuit connected in series with an adjacent individual photovoltaic module panel, and a MOSFET or IGBT switch for operating the bypass circuit switching, wherein the MOSFET or IGBT switch operates by itself by energizing a diode or the It is operated according to the emergency stop or operation restart control command applied from the control processing unit,
The control processing unit and the wireless communication unit use a Bluetooth wireless mesh between individual solar module panels by a distributed control protocol that relays messages of voltage and current measurement data or arc fault detection data of individual solar module panels to adjacent individual solar module panels. The network is configured, but the control processing unit and the wireless communication unit allocate a group address of a string or array to which the respective individual solar module panels are connected, and send an emergency stop or operation restart control command to the group address through the mesh network. As the control message is transmitted in multi-path, a separate gateway or Internet-based communication is not required, and the mesh network applies a quality-of-service (QoS) protocol that guarantees the priority of packet delivery on the network. Emergency stop command is transmitted with high priority, and monitoring data including voltage, current, power, amount of power, and operation status is transmitted with low priority, so that the emergency stop command is always delivered with priority over the monitoring data on the mesh network. Distributed module-level solar power generation monitoring and control system based on a decentralized wireless mesh network with
According to claim 1,
The control processing unit controls by applying an emergency stop or operation restart control command to the on/off switch and the bypass circuit unit to open and close the on/off switch and switch the bypass circuit unit according to the occurrence or release of the abnormal condition Distributed module-level solar power generation monitoring and control system based on decentralized wireless mesh network
According to claim 1,
The control processing unit applies a control command to resume operation after a certain period of time when the occurrence of the abnormal condition is released, and controls the distributed module level solar power generation monitoring and control system
According to claim 1,
The arc fault detection unit extracts a fundamental component and a harmonic component by fast Fourier transform (FFT) of the DC current detected by the current detection unit, and the ratio of a specific harmonic component is greater than or equal to a preset ratio compared to the extracted fundamental component Decentralized wireless mesh network base, characterized in that the Fast Fourier Transform (FFT) and the arc fault detection algorithm are performed by the control processing unit so as to detect an arc fault and block the on/off switch Distributed module level solar power generation monitoring and control system
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