KR20230092282A - Monitoring system of photovoltaic generation that enables remote control of junction box - Google Patents

Abstract

The present invention relates to a solar power generation monitoring system capable of remote control of a junction box, and more particularly, by checking DC power information of the junction box and AC power information of an inverter to calculate a power conversion rate, determining whether the junction box is faulty, and determining whether the junction box is faulty. It is about a photovoltaic power generation monitoring system capable of remotely controlling a junction box that can predict the replacement time by diagnosing deterioration and protect facilities such as inverters/systems through junction box control according to weather factors.

Description

Photovoltaic generation monitoring system that enables remote control of junction box {Monitoring system of photovoltaic generation that enables remote control of junction box}

The present invention relates to a solar power generation monitoring system capable of remote control of a junction box, and more particularly, by checking DC power information of the junction box and AC power information of an inverter to calculate a power conversion rate, determining whether the junction box is faulty, and determining whether the junction box is faulty. It is about a photovoltaic power generation monitoring system capable of remotely controlling a junction box that can predict the replacement time by diagnosing deterioration and protect facilities such as inverters/systems through junction box control according to weather factors.

Photovoltaic power generation refers to a power generation method that converts sunlight into electrical energy using the photovoltaic effect. DC power is converted into AC power, and the converted AC power is supplied to a system or load through a switchboard.

In the process of continuously performing photovoltaic power generation, if an abnormality occurs in a device (a module constituting a cell array, a junction box, etc.), power supply may be interrupted or an accident such as fire may occur, thereby changing the state of the device. It is important to diagnose and respond promptly, and as described in the following patent literature, a system for monitoring solar power generation has been widely developed.

<Patent Document>

Patent Document 1: Patent Publication No. 10-2016-0078532 (published on July 5, 2016) "System and method for diagnosing abnormalities by solar module"

Patent Document 2: Registered Patent No. 10-1420644 (registered on July 11, 2014) "wired and wireless integrated access panel applied to solar power plant monitoring system"

However, the conventional photovoltaic power generation monitoring system has problems in that the abnormality diagnosis process is complicated, aging prediction is difficult, and response to external weather factors (lightning, strong wind, etc.) is not precise.

The present invention has been made to solve the above problems,

The present invention checks the DC power information of the junction box and the AC power information of the inverter, calculates the power conversion rate, determines whether the junction box is out of order, diagnoses the aging of the junction box, and predicts the replacement time. Its purpose is to provide a photovoltaic monitoring system.

In addition, an object of the present invention is to provide a photovoltaic power generation monitoring system capable of remotely controlling a junction box capable of protecting equipment such as an inverter/system through control of a junction box according to weather factors.

The present invention is implemented by an embodiment having the following configuration in order to achieve the above object.

According to one embodiment of the present invention, the photovoltaic power generation monitoring system according to the present invention includes a first sensor for sensing DC power information of a junction box; a second sensor for sensing AC power information of an inverter that converts DC power output from the junction box into AC power; Monitoring with a condition diagnosis unit that determines the failure of the junction box by checking the information output from the first sensor and the second sensor, calculates the power conversion rate from DC power to AC power, and predicts the replacement time by diagnosing the aging of the junction box It is characterized in that it includes; server.

According to another embodiment of the present invention, in the photovoltaic monitoring system according to the present invention, when the monitoring server checks weather forecast information and predicts a weather factor that may cause a failure of the junction box, the weather factor is predicted It is characterized in that it further comprises a facility protection unit for outputting a control signal to stop the operation of the junction box at the time of being.

According to another embodiment of the present invention, in the photovoltaic monitoring system according to the present invention, the state diagnosis unit checks the information output from the first sensor and the second sensor to determine the power conversion rate of DC power to AC power. A calculation module for calculating; a failure determination module for outputting a signal indicating that a failure has occurred in the junction box when the power conversion rate output from the calculation module is smaller than a preset failure limit value; and a power conversion rate output from the calculation module If the cases belonging to the set abnormal limit range are more than a certain number of times during a certain period, an abnormality determination module that outputs a signal that an abnormality has occurred, although it is not a failure of the junction box, and a unit time change in the power conversion rate output from the calculation module is checked. It is characterized in that it includes an emergency decision module for calculating the slope and outputting a signal indicating that an emergency situation has occurred in the connection box when the slope is out of a preset slope range.

According to another embodiment of the present invention, in the photovoltaic monitoring system according to the present invention, the condition diagnosis module analyzes the power conversion rate output from the calculation module to diagnose aging of the junction box and predicts the replacement time. The lifespan prediction module further includes an absolute evaluation module that calculates the predicted lifespan by matching the currently calculated power conversion rate to a preset lifespan prediction table, and a change in the power conversion rate per unit time is checked and calculated by the absolute evaluation module. It is characterized in that it includes a relative evaluation module for correcting the predicted lifespan.

According to another embodiment of the present invention, in the photovoltaic monitoring system according to the present invention, the facility protection unit calculates the impact level affected by the meteorological factor according to the connection state for each connection, and the specific weather factor It is characterized in that operation stop control is performed only for the junction box having an impact level capable of causing a failure in the event of occurrence.

According to another embodiment of the present invention, in the photovoltaic power generation monitoring system according to the present invention, the facility protection unit is affected by weather factors according to the state of the junction box by using the information of the junction box collected for each period. A standard setting module that creates a standard model to calculate the impact level for each junction box, and inputs the state information of a specific junction box into the standard module created in the standard description module to determine the meteorological factors that may cause failure in the junction box It is characterized by including an impact level module for acquiring and analyzing information and calculating an impact level for the junction box according to the severity of the meteorological factor.

According to another embodiment of the present invention, in the photovoltaic monitoring system according to the present invention, the facility protection unit collects and analyzes weather forecast information and collects weather information for outputting information on weather factors that may cause failures in the access box. module, an accident degree prediction module that determines whether a failure of the junction box is expected by matching the meteorological factor information output from the weather information collection module and the impact grade output to the impact level module for each junction box, and the accident degree prediction module It is characterized in that it further comprises an operation control module for outputting a control signal to stop the operation of the junction box in which failure is expected at the time when the occurrence of the meteorological factor is predicted when information that failure is expected is output.

The present invention can obtain the following effects by combining and using the above embodiments and configurations to be described below.

The present invention has the effect of determining the failure of the junction box by checking the DC power information of the junction box and the AC power information of the inverter, calculating the power conversion rate, and predicting the replacement time by diagnosing the deterioration of the junction box.

In addition, the present invention has an effect of protecting facilities such as inverters/systems through junction box control according to meteorological factors.

1 is a block diagram of a photovoltaic monitoring system according to an embodiment of the present invention.
Figure 2 is a block diagram showing the detailed configuration of the photovoltaic power generation unit of Figure 1;
Figure 3 is a block diagram showing the detailed configuration of the monitoring server of Figure 1;
Figure 4 is a block diagram showing the detailed configuration of the state judgment unit of Figure 3;
5 is a block diagram showing the detailed configuration of the facility protection unit of FIG. 4;

Hereinafter, preferred embodiments of a photovoltaic power generation monitoring system capable of remotely controlling a junction box according to the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Throughout the specification, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated, and also described in the specification. Terms such as "...unit" and "...module" refer to a unit that processes at least one function or operation, and may be implemented as hardware or software or a combination of hardware and software.

Referring to FIGS. 1 to 5, a solar power generation monitoring system capable of remote control of a junction box according to an embodiment of the present invention is described. The solar power generation monitoring system generates and outputs DC power using sunlight. A first sensor 121 for sensing DC power information of the junction box 120 of the photovoltaic unit 100 and a second sensor for sensing AC power information of the inverter 130 of the photovoltaic unit 100 131 and the information output from the first sensor 121 and the second sensor 131 are checked to calculate the power conversion rate from DC power to AC power to determine whether the connection box 120 is out of order and connected. A monitoring server 1 for diagnosing deterioration of the box 120 and predicting a replacement time is included. Prior to a detailed description of the photovoltaic power generation monitoring system, looking at the photovoltaic power generation unit to be monitored by the system, the photovoltaic power generation unit 100 is formed by connecting a plurality of strings to which solar modules are connected in series in parallel A cell array 110, a junction box 12 that collects DC power output from the cell array 110 and protects the connected cell array 110, an inverter 130, etc., and the junction box 120 and an inverter 130 that converts the DC power output from the inverter 130 into AC power, and the AC power converted and output by the inverter 130 is supplied to the load or/and grid through the switchboard 200. The junction box 120 has characteristics of high voltage and high current, so it is easy to fail due to various factors (deterioration, meteorological factors, etc.), and there is a high risk of accidents when a failure occurs. Since it serves to protect devices connected to the rear end, when the junction box 120 fails, the entire photovoltaic power generation unit may be seriously damaged. Accordingly, the present invention diagnoses and predicts the failure of the junction box 120 according to the current state, and controls the junction box 120 according to weather factors predicted in the future to prevent accidents in advance. The junction box 120 may be a conventional junction box, for example, although not shown, a configuration for opening and closing a circuit (relay, etc.), a configuration for preventing reverse current (diode, etc.), a configuration for blocking overcurrent (fuse, etc.) etc. may be included. The first sensor 121 is configured to sense DC power information collected in the junction box 120 at regular intervals, and is a current sensor and a voltage sensor commonly used to sense DC power information of the junction box 120. etc. may be used, and the second sensor 131 is configured to sense information on AC power converted and outputted by the inverter 130 at regular intervals, and is typically used to sense AC power information of the inverter 130. Current sensors, voltage sensors, and the like that are used may be used.

The monitoring server 1 checks the information output from the first sensor 121 and the second sensor 131 and calculates the power conversion rate of DC power to AC power to determine whether the junction box is out of order and determines the aging of the junction box. It is a configuration that predicts the replacement time by diagnosing, and includes a transmission/reception unit 11, a state determination unit 12, a facility protection unit 13, a storage unit 14, a control unit 15, and the like. The storage unit 14 stores information necessary for the operation of the photovoltaic monitoring system and information generated by the system, and the control unit 15 controls the overall operation of the monitoring server 1.

The transceiver 11 is connected to the connection box 120, the inverter 130, a weather information system (not shown), and an operator terminal (not shown) to transmit and receive information.

The state determination unit 12 checks the information output from the first sensor 121 and the second sensor 131 and calculates the power conversion rate of DC power to AC power to determine whether the connection box is faulty and connects As a configuration for diagnosing deterioration and predicting replacement time, it includes a calculation module 121, a failure determination module 122, an abnormality determination module 123, an emergency determination module 124, a life prediction module 125, and the like.

The calculation module 121 checks the information output from the first sensor 121 and the second sensor 131 and calculates the power conversion rate of DC power to AC power. The calculation of the power conversion rate is conventional. Since the method of is used, a detailed description thereof will be omitted.

The failure determination module 122 outputs a signal indicating that a failure has occurred in the connection box 120 and transmits it to the operator terminal when the power conversion rate output from the calculation module 121 is smaller than a predetermined failure limit value, , A control signal for stopping the operation of the junction box 120 is output. The operator terminal is a configuration used by the operator of the photovoltaic monitoring system to exchange information with the monitoring server 1. When the junction box 120 receives a control signal to stop its operation, the operation of the junction box may be stopped by, for example, turning off a circuit by controlling a relay. The failure limit value is a numerical value indicating that the junction box 120 is in a failure state because it does not perform normal operation. For example, by collecting data through repeated experiments and analyzing the data, the power conversion rate immediately before failure occurs It can be set as a failure limit value.

The abnormality determination module 123 outputs a signal indicating that an abnormality has occurred, although it is not a failure of the junction box, when the power conversion rate output from the calculation module 121 falls within a predetermined abnormal limit range at least a certain number of times during a certain period of time. This is a configuration for transmitting to the operator terminal. The abnormal limit range is a numerical value of a case where the junction box 120 is not currently out of order, but a failure may occur in the future, and may be set using data obtained by repeating experiments under specific conditions, for example. The ideal limit range has a higher value than the failure limit value.

The emergency determination module 124 calculates the slope by checking the change in the power conversion rate output from the calculation module 121 per unit time, and sends a signal that an emergency situation has occurred to the connection box when the slope is out of a preset slope range. Outputs and transmits to the operator terminal, and outputs a control signal for stopping the operation of the junction box 120. If the junction box is operating normally, but an external factor such as lightning occurs, a problem occurs in the junction box and the power conversion rate may change rapidly. (If the slope is out of the range, there is a problem with the connection box) is calculated, and the emergency decision module outputs a signal indicating that an emergency situation has occurred when the calculated slope is out of the slope range.

The life prediction module 125 analyzes the power conversion rate output from the calculation module 21 and diagnoses the deterioration of the junction box to predict the replacement time. The currently calculated power conversion rate is matched with a preset life prediction table An absolute evaluation module (not shown) that calculates predicted lifespan and a relative evaluation module (not shown) that corrects the predicted lifespan calculated by the absolute evaluation module by checking the change in power conversion rate per unit time. Information on the predicted lifespan calculated by the relative evaluation module is transmitted to the operator terminal. Since the junction box deteriorates with time, it is not in a faulty state, but if the power conversion rate is high, it has a lot of life left, and if the power conversion rate is low, it can be determined that the lifespan is short. And, the remaining life of the junction box can be predicted by matching the current power conversion rate to the life prediction table. However, since the life prediction table is set on an absolute basis and can deteriorate rapidly and gently unlike the average depending on the state of individual junction boxes, the change in power conversion rate per unit time is checked to correct the previously calculated life expectancy. . For example, when the power conversion rate is 70%, the remaining life is set to 2 months in the life prediction table, and it is set that the average power conversion rate decreases by 5% per cycle. At this point, the power conversion rate is 70% and the previous cycle When the power change rate of is 72%, the absolute evaluation module outputs a remaining lifespan of 2 months, and the relative evaluation module determines that aging is progressing slowly and corrects the remaining lifespan to obtain a residual lifespan greater than 2 months (eg, , 3 months, etc.)

The equipment protection unit 13 checks the weather forecast information and outputs a control signal to stop the operation of the junction box at the time when the weather factor is predicted when a meteorological factor that may cause a failure of the junction box is predicted. As such, it includes a standard setting module 131, an impact level module 132, a weather information collection module 133, an accident degree prediction module 134, an operation control module 135, and the like. As described above, the junction box 120 has characteristics of high voltage and high current, so it is easy to fail during operation due to weather factors such as lightning and strong wind. However, since each junction box has a different state and the meteorological factors that cause failure are not the same (e.g., junction box A is in good condition, it may not fail even if 5 lightning strikes occur for a certain period of time, Junction box B is in poor condition (deterioration is progressing, etc.), and even if two lightning strikes occur during a certain period of time, a failure can occur), all junction boxes stop operating just because lightning or strong winds are expected. In this case, even junction boxes that are not likely to fail are stopped, resulting in reduced efficiency. Therefore, the present invention calculates the impact level affected by weather factors for each junction box according to the state of the junction boxes, and prevents failures when specific meteorological factors occur. Operation stop control is performed only for the junction box with the impact level that can occur.

The standard setting module 131 is a configuration for generating a standard model for calculating the impact level affected by weather factors for each access box according to the state of the access box by using the information of the access box collected at regular intervals. The standard model accumulates and analyzes the failure cases of the junction box according to the state of the junction box and meteorological factors, that is, the state information of the junction box (inspection time information stored in the storage unit, remaining life information predicted in the life prediction module, capacity of parts) It can be created by finding a non-linear relationship and calculating weights by performing machine learning with the failure occurrence information of connecting information, period of use of parts, etc.) and meteorological factor information (lightning occurrence frequency, rainfall, etc.) as input values. there is. Through the standard model, it is possible to check information on meteorological factors that cause failures when the junction box is in a specific state.

The influence class module 132 inputs state information of a specific junction box into the standard module generated by the standard description module to obtain and analyze information on meteorological factors that may cause failures in the junction box, and determine the severity of the meteorological factors. It is a configuration for calculating the impact level of the junction box according to. For example, a strong wind strength of A value is set as impact class 1, a strong wind strength of B value is set as impact class 2, and a strong wind strength of C value is set as impact class 3. If the information is a strong wind strength of C value, it is calculated as impact level 3.

The weather information collection module 133 connects to the weather information system, collects and analyzes weather forecast information, and outputs information on meteorological factors (lightning, strong wind, etc.) that may cause a failure of the connection box. The system may be a system operated by the Korea Meteorological Administration or a company providing weather information. Since various and sophisticated weather forecast information such as lightning strikes and strong winds are generated by government agencies and private companies, the weather information collection module 133 collects the weather forecast information to determine whether there are meteorological factors that may cause failure of the junction box. do.

The accident degree prediction module 134 matches the meteorological factor information output from the weather information collection module 133 and the impact grade output from the impact rating module 132 for each junction box to determine whether failure of the junction box is expected is a composition For example, if one connection box has an impact level of 3, and the meteorological factor information output from the meteorological information collection module 133 has information on a strong wind having an intensity greater than the C value, the accident degree prediction module 134 information that a failure is expected is output, and other access boxes have an impact level of 2, and the meteorological factor information output from the weather information collection module 133 is information on strong winds having a strength lower than the B value. If there is, the accident degree prediction module 134 does not output information in which a failure is expected.

The operation control module 135 controls to stop the operation of the junction box in which failure is expected at the time when the occurrence of the meteorological factor is predicted, when information that a failure is expected is output from the accident degree prediction module 134. It is a configuration for outputting a signal to the connection box 120.

In the above, the applicant has described various embodiments of the present invention, but such embodiments are only one embodiment for implementing the technical idea of the present invention, and any changes or modifications are made according to the present invention as long as the technical idea of the present invention is implemented. should be construed as falling within the scope of

1: monitoring server 11: transmission and reception unit 12: state determination unit
13: facility protection unit 14: storage unit 15: control unit
121: calculation module 122: fault determination module 123: abnormality determination module
124: emergency judgment module 125: life prediction module 131: standard setting module
132: Impact rating module 133: Weather information collection module 134: Accident degree prediction module
135: operation control module 100: photovoltaic power generation unit 200: switchboard
110: cell array 120: connection box 130: inverter
121: first sensor 131: second sensor

Claims (7)

a first sensor for sensing DC power information of the junction box; a second sensor for sensing AC power information of an inverter that converts DC power output from the junction box into AC power; Monitoring with a condition diagnosis unit that determines the failure of the junction box by checking the information output from the first sensor and the second sensor, calculates the power conversion rate from DC power to AC power, and predicts the replacement time by diagnosing the aging of the junction box A solar power generation monitoring system comprising a; server. According to claim 1,
The monitoring server checks the weather forecast information and when a meteorological factor that can cause a failure of the junction box is predicted, a facility protection unit outputting a control signal to stop the operation of the junction box at the time when the weather factor is predicted A solar power monitoring system comprising: According to claim 2,
The state diagnosis unit checks the information output from the first sensor and the second sensor and calculates a power conversion rate from DC power to AC power, and a power conversion rate output from the calculation module is greater than a predetermined fault limit If the junction box is small, if the power conversion rate output from the failure determination module and the calculation module outputs a signal indicating that a failure has occurred in the junction box falls within a predetermined abnormal limit range a certain number of times or more over a certain period of time, it is not a failure of the junction box. An abnormality determination module that outputs a signal that an abnormality has occurred, and a change in the power conversion rate output from the calculation module per unit time are checked to calculate the slope, and if the slope is out of the preset slope range, an emergency situation has occurred in the connection box A photovoltaic power generation monitoring system comprising an emergency judgment module for outputting a signal. According to claim 3,
The state diagnosis unit further includes a life prediction module for predicting a replacement time by diagnosing aging of the junction box by analyzing the power conversion rate output from the calculation module,
The lifespan prediction module includes an absolute evaluation module that calculates the predicted lifespan by matching the currently calculated power conversion rate to a preset lifespan prediction table, and a change in the power conversion rate per unit time to correct the predicted lifespan calculated by the absolute evaluation module. A solar power generation monitoring system comprising a relative evaluation module. According to claim 4,
The facility protection unit calculates the impact level affected by weather factors according to the condition of the connection box for each connection box, and controls the operation of only the connection box with the impact level that can cause a failure when a specific weather factor occurs A solar power monitoring system characterized in that. According to claim 4,
The facility protection unit uses the information of the junction boxes collected at regular intervals, a standard setting module for generating a standard model for calculating the impact level affected by weather factors according to the state of the junction box for each junction box, and a specific connection By inputting the condition information of the box into the standard module generated by the standard description module, obtaining and analyzing information on meteorological factors that may cause failure in the junction box, and calculating the impact grade of the junction box according to the severity of the meteorological factor A photovoltaic power generation monitoring system comprising an impact rating module. According to claim 6,
The facility protection unit collects and analyzes weather forecast information and outputs information on meteorological factors that may cause failures in the junction box, and weather factor information output from the weather information collection module for each junction box and the impact grade An accident degree prediction module that determines whether a failure of the junction box is expected by matching the impact grade output to the module, and if information that a failure is expected is output from the accident degree prediction module, the failure occurs at the time when the occurrence of the meteorological factor is predicted The photovoltaic power generation monitoring system, characterized in that it further comprises an operation control module for outputting a control signal to stop the operation of the expected connection box.

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