Intelligent switching strategy for regional distributed photovoltaic power generation system cluster

Abstract

The invention discloses a regional distributed photovoltaic power generation system cluster intelligent switching-out strategy, and belongs to the technical field of distributed photovoltaic power generation system optimization operation. According to the invention, meteorological monitoring station data and distributed photovoltaic power generation system cluster operation state data are collected at a set time resolution by using a communication system; according to the meteorological monitoring station data and the distributed photovoltaic power generation system cluster operation state data, the distributed photovoltaic power generation system cluster operation state data is acquired. Constructing a distributed photovoltaic power generation system cluster cut-out calculation model based on the operation duration; constructing a distributed photovoltaic power generation system cut-out calculation model based on the operation state of the power distribution network; and constructing a distributed photovoltaic power generation system health state analysis model. A cut-out calculation model based on the health state of the distributed photovoltaic power generation system is constructed; and fusing the constructed cut-out calculation model to obtain the distributed photovoltaic power generation system cluster intelligent cut-out decision model. And the problem of how to reasonably switch out the distributed photovoltaic power generation system and the like which troubles the optimized operation of the power grid is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of optimized operation of distributed photovoltaic power generation systems, and in particular relates to an intelligent cluster switching strategy for regional distributed photovoltaic power generation systems. Background Art

[0002] By September 2023, the installed capacity of distributed photovoltaic power generation reached 225 million kilowatts, accounting for 43.27% of the total installed photovoltaic power generation capacity. Distributed photovoltaic power generation is characterized by small units, large numbers, low voltage, and irregular distribution. The massive amount of distributed photovoltaic power generation connected to the power grid poses serious challenges to the safe and stable operation of the power grid. To ensure safe and stable operation, the power grid needs to disconnect some distributed photovoltaic power generation systems within the region. However, how to properly disconnect these distributed photovoltaic power generation systems has become a problem that hinders the optimal operation of the power grid. Summary of the Invention

[0003] The purpose of the present invention is to address the problem of unsafe and unstable power grid operation caused by unreasonable switching of distributed photovoltaic power generation systems in the prior art. This solution constructs multiple switching calculation models by comprehensively considering the influencing factors of the distributed photovoltaic power generation system, such as operating time, line voltage, line frequency, photovoltaic panel temperature, and converter temperature, and then healthily and actively switches out some distributed photovoltaic power generation systems in the area, solving the problem of unsafe and unstable power grid operation caused by unreasonable switching of distributed photovoltaic power generation systems in the prior art, and ensuring the safe and stable operation of the distribution network.

[0004] Specifically, the present invention provides a cluster intelligent switch-out strategy for a regional distributed photovoltaic power generation system, comprising the following steps: S1. Using the communication system to collect meteorological monitoring station data and distributed photovoltaic power generation system cluster operating status data at a set time resolution; S2. Based on the relationship between the continuous operation time of the distributed photovoltaic power generation system cluster and the switch-out decision, a distributed photovoltaic power generation system cluster switch-out calculation model based on the operation time is constructed; S3. Constructing a distributed photovoltaic power generation system cut-out calculation model based on the distribution network operation status according to the voltage and frequency of the line at the access point of the distributed photovoltaic power generation system; S4. Constructing a health status analysis model based on the distributed photovoltaic power generation system according to the photovoltaic panel temperature and the converter temperature, and then constructing a cut-out calculation model based on the health status of the distributed photovoltaic power generation system; S5: Integrate the switch-out calculation models constructed in S2, S3, and S4 to obtain a distributed photovoltaic power generation system cluster intelligent switch-out decision model.

[0005] Preferably, the distributed photovoltaic power generation system cluster operating status data includes photovoltaic system continuous operation time, photovoltaic system power, photovoltaic system current, voltage and frequency of the line at the access point of the distributed photovoltaic power generation system, photovoltaic panel temperature and converter temperature.

[0006] As a preference, in said S2, the distributed photovoltaic power generation system cluster cut-out calculation model based on the running time Specifically expressed as: ; Where, For the The operating time of a distributed photovoltaic power generation system, the time unit is hours, is the number of power generation systems in the distributed photovoltaic power generation system cluster, is the average operating time of the distributed photovoltaic power generation system cluster, The first The cut-out value of the distributed photovoltaic power generation system, is the time cut-out factor of the distributed photovoltaic power generation system.

[0007] As a preference, in said S3, the distributed photovoltaic power generation system cut-out calculation model based on the distribution network operation state Specifically expressed as: ; Where, According to the The cut-out value is calculated based on the frequency and voltage values ​​at the access point of the distributed photovoltaic power generation system. Indicates the The frequency value at the access point of the distributed photovoltaic power generation system is Indicates the The voltage value at the access point of the distributed photovoltaic power generation system, According to the The cut-out value is calculated based on the frequency and voltage values ​​at the access point of the distributed photovoltaic power generation system. When the voltage of the distribution network line is in the yellow warning state, the voltage deviation value is in the range of -10% to -5% and 5% to 10% when the cut-out coefficient is When the distribution network line voltage is in red warning, the voltage deviation value exceeds the cut-out coefficient of 10%; When the frequency of the distribution network line is in yellow warning, the frequency deviation value is in the range of -2% to -1% and 1% to 2%. When the distribution network line frequency is in red warning, the frequency deviation value is less than -2% or greater than 2% of the cut-out coefficient.

[0008] Preferably, the S4 comprises the following steps: S41. Based on the temperature of the photovoltaic panels of the distributed photovoltaic power generation system, a photovoltaic panel health status analysis model is constructed using the temperature distribution characteristics; S42. Based on the converter temperature of the distributed photovoltaic power generation system, a converter health status analysis model is constructed using temperature distribution characteristics; S43. Construct a switch-out calculation model based on the health status of the distributed photovoltaic power generation system according to the photovoltaic panel health status analysis model and the converter health status analysis model.

[0009] Preferably, the photovoltaic panel health status analysis model is specifically expressed as: ; ; In the formula, expectation Represents the average temperature of photovoltaic panels in the distributed photovoltaic power generation system cluster, Indicates the Distributed photovoltaic power generation system The temperature of each photovoltaic panel, Indicates the The degree to which the photovoltaic panel temperature of a distributed photovoltaic power generation system deviates from the average value, represents the number of distributed photovoltaic power generation systems, Indicates the number of photovoltaic panels in a distributed photovoltaic power generation system.

[0010] Preferably, the converter health status analysis model is specifically expressed as: ; ; In the formula, expectation represents the average converter temperature of the distributed photovoltaic power generation system cluster, Indicates the Distributed photovoltaic power generation system The temperature of the converter, Indicates the The degree to which the converter temperature of a distributed photovoltaic power generation system deviates from the average value, represents the number of distributed photovoltaic power generation systems, Indicates the number of converters in a distributed photovoltaic power generation system.

[0011] As a preference, the switch-out calculation model based on the health status of the distributed photovoltaic power generation system Specifically expressed as: ; Where, According to the The cut-out value is calculated based on the photovoltaic panel temperature and converter temperature of the distributed photovoltaic power generation system. 、 、 and is the cut-out coefficient of the photovoltaic panels and converters in the distributed photovoltaic power generation system. The size of the cut-out coefficient needs to be determined through fault experiments of the photovoltaic panels and converters. No. Set of photovoltaic panel temperature values ​​of distributed photovoltaic power generation system, No. Set of temperature values ​​of the converter of the distributed photovoltaic power generation system.

[0012] Preferably, in S5, the specific expression of the distributed photovoltaic power generation system cluster intelligent switching decision model is: ; Where, For the distributed photovoltaic power generation system to be cut out, For the Set of distributed photovoltaic power generation system cut-out function values, for The weight of for The weight of for The weight of .

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. This scheme proposes a distributed photovoltaic power generation system cluster cut-out calculation model based on the running time according to the relationship between the continuous running time of the distributed photovoltaic power generation system cluster and the cut-out decision. At present, the method for cutting out the distributed photovoltaic power generation system cluster is mainly done manually by the staff. In the process of cutting out the distributed photovoltaic power generation system, the staff did not consider the system operation time, the safe and stable operation status of the distribution network line and the operation status of the distributed photovoltaic power generation system itself, which makes the manual cutting out method extremely unreasonable and unfair; Model In the process, the longer the distributed photovoltaic power generation system has been running, the greater the possibility of being cut out. This ensures that all distributed photovoltaic power generation systems are cut out in turn, ensuring the economy of the distributed photovoltaic power generation system cluster.

[0014] 2. The voltage and frequency state parameters of the distributed photovoltaic power generation system connected to the distribution network line in this scheme are proposed, and a distributed photovoltaic power generation system cut-out calculation model based on the operating status of the distribution network line is proposed. In the process of switching off, the existing distributed photovoltaic power generation system does not take into account the voltage, frequency and other state parameters of the access line, so that the distributed photovoltaic power generation system on the distribution line with excessive voltage and frequency is not switched off in time, which brings great challenges to the safe and stable operation of the distribution network. In this model, the probability of a distributed photovoltaic system being disconnected is determined by the degree to which the voltage and frequency of the distribution network lines exceed the standard values. The greater the degree to which the voltage and frequency of the distribution network lines exceed the standard values, the greater the probability that the distributed photovoltaic system on that line will be disconnected, thereby ensuring the safe and stable operation of the distribution network.

[0015] 3. This solution proposes a switch-out calculation model based on the health status of distributed photovoltaic power generation system based on the health status analysis model of distributed photovoltaic power generation system. At present, the disconnection of distributed photovoltaic power generation systems is completed by staff. The staff has a certain degree of randomness and subjectivity in the process of disconnecting distributed photovoltaic power generation systems, and does not consider the health status of the distributed photovoltaic power generation systems themselves, so that some distributed photovoltaic power generation systems in a fault state are not disconnected in time, affecting the safe and stable operation of the distributed photovoltaic power generation systems; Model In the process of cutting out the distributed photovoltaic power generation system, the model considers the degree to which the temperature of the photovoltaic panels and the converter deviates from the healthy state value. The greater the deviation, the greater the possibility of the distributed photovoltaic power generation system being cut out. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a system flow diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of a cut-out strategy interface according to an embodiment of the present invention; Figure 3 A schematic diagram of a calculation procedure for a cut-out strategy according to an embodiment of the present invention; Figure 4 This is a diagram of the cut-out calculation results of an embodiment of the present invention. DETAILED DESCRIPTION

[0017] Example 1: Figure 1 - Figure 4 As shown, a cluster intelligent switch-out strategy for a regional distributed photovoltaic power generation system includes: Figure 1 The figure shows a flow chart of a regional distributed photovoltaic power generation system cluster intelligent switching-out strategy proposed in this embodiment. The specific steps of the regional distributed photovoltaic power generation system cluster intelligent switching-out strategy are: (1) The grid communication system is used to collect data from meteorological monitoring stations and the operating status data of distributed photovoltaic power generation system clusters (distributed photovoltaic power generation system continuous operation time, power, current, voltage, frequency, photovoltaic panel temperature and converter temperature, etc.). The data collection time resolution is 1 minute.

[0018] On the one hand, the present invention proposes a device for a regional distributed photovoltaic power generation system cluster intelligent cut-out strategy, which adopts an independent operating system, including communication equipment, a distributed photovoltaic power generation system cluster intelligent cut-out model operating platform and a distributed photovoltaic power generation system cluster intelligent cut-out model.

[0019] Among them, the communication equipment is responsible for obtaining meteorological data and photovoltaic system operating status data from meteorological monitoring stations and distributed photovoltaic power generation system clusters. The communication equipment is usually a dedicated power communication network or 5G communication equipment; the distributed photovoltaic power generation system cluster intelligent cut-out model operation platform provides support for the operation of the distributed photovoltaic power generation system cluster intelligent cut-out model; the distributed photovoltaic power generation system cluster intelligent cut-out model intelligently decides the distributed photovoltaic power generation system that needs to be cut out based on the operating time of the distributed photovoltaic power generation system, the voltage and frequency status parameters of the access line and the health status of the distributed photovoltaic power generation system.

[0020] (2) Based on the relationship between the continuous operation time of distributed photovoltaic power generation system clusters and the switch-out decision, a calculation model for the switch-out probability of distributed photovoltaic power generation system clusters based on the operation time is proposed. .

[0021] For the model , when the operating time of the distributed photovoltaic power generation system is less than the regional average operating time, the model The output value of is small, indicating that the probability of the distributed photovoltaic power generation system being cut out is small; when the operating time of the distributed photovoltaic power generation system is greater than the regional average operating time, the model The output value of should increase rapidly with the increase of running time, indicating that the probability of the distributed photovoltaic power generation system being cut out increases rapidly. According to the relationship between the continuous running time of the distributed photovoltaic power generation system cluster and the probability of being cut out, the model The calculation formula is shown in formula (1).

[0022] (1) In formula (1), For the The operating time of a distributed photovoltaic power generation system, in hours; is the number of power generation systems in the distributed photovoltaic power generation system cluster; is the average operating time of the distributed photovoltaic power generation system cluster; is the time-switching factor of the distributed photovoltaic power generation system, the time-switching factor The value of is determined by the operating status of the regional distributed photovoltaic power generation system and the power grid, and the value range is generally set between [1,5]. is the first Set of cut-out values ​​for distributed photovoltaic power generation systems.

[0023] This scheme proposes a distributed photovoltaic power generation system cluster cut-out calculation model based on the running time according to the relationship between the continuous running time of the distributed photovoltaic power generation system cluster and the cut-out decision. At present, the method for cutting out the distributed photovoltaic power generation system cluster is mainly done manually by the staff. In the process of cutting out the distributed photovoltaic power generation system, the staff did not consider the system operation time, the safe and stable operation status of the distribution network line and the operation status of the distributed photovoltaic power generation system itself, which makes the manual cutting out method extremely unreasonable and unfair; Model In the process, the longer the distributed photovoltaic power generation system has been running, the greater the possibility of being cut out. This ensures that all distributed photovoltaic power generation systems are cut out in turn, ensuring the economy of the distributed photovoltaic power generation system cluster.

[0024] (3) Based on the voltage and frequency state parameters of the distributed photovoltaic power generation system connected to the distribution network, a distributed photovoltaic power generation system cut-out calculation model based on the distribution network operation status is proposed. .

[0025] In computational models In the data, when the deviations of the voltage and frequency of the distributed photovoltaic power generation system connected to the distribution network from the standard values ​​are within a reasonable range (±5% of the voltage standard value, ±1% of the frequency standard value), the probability of the distributed photovoltaic power generation system being cut out is zero; when the deviations of the voltage and frequency of the distributed photovoltaic power generation system connected to the distribution network from the standard values ​​are in the yellow warning range (voltage deviation values ​​are in the range of -10% to -5% and 5% to 10%, frequency deviation values ​​are in the range of -2% to -1% and 1% to 2%), the probability of the distributed photovoltaic power generation system being cut out increases with the increase of the voltage and frequency deviation amplitude; when the deviations of the voltage and frequency of the distributed photovoltaic power generation system connected to the distribution network from the standard values ​​are in the red warning range (voltage deviation values ​​are less than -10% or greater than 10%, frequency deviation values ​​are less than -2% or greater than 2%), the probability of the distributed photovoltaic power generation system being cut out increases rapidly with the increase of the voltage and frequency deviation amplitude. According to the deviation relationship between the voltage and frequency of the distributed photovoltaic power generation system connected to the distribution network and the standard values, a distributed photovoltaic power generation system cut-out calculation model is constructed. As shown in formula (2).

[0026] (2) In formula (2), According to the The cut-out value is calculated based on the frequency and voltage values ​​at the access point of the distributed photovoltaic power generation system. It is the cut-out coefficient when the distribution network line voltage is in the yellow warning range (voltage deviation value is between -10% and -5%, 5% and 10%). The cut-out coefficient when the distribution network line voltage is in red warning (voltage deviation value exceeds 10%); It is the cut-out coefficient when the distribution network line frequency is in the yellow warning (frequency deviation value is between -2% and -1%, 1% and 2%). It is the cut-out coefficient when the distribution network line frequency is in red warning (frequency deviation value is less than -2% or greater than 2%); No. The voltage deviation value at the access point of the distributed photovoltaic power generation system is No. The frequency deviation value at the access point of the distributed photovoltaic power generation system. To ensure the consistency of the dimensions, all variables in the formula are expressed in per unit. Voltage cut-out coefficient and , frequency cut-out coefficient and The specific value of needs to be analyzed and calibrated based on the actual data during the operation of the distribution network. In addition, the voltage deviation value and the specific division of the voltage deviation value are as follows. According to the power quality evaluation standard of the State Grid Corporation of China, it can be known that: (1) The normal fluctuation range of the distribution network voltage is between ±5%, and the normal fluctuation range of the frequency is between ±1%; (2) When the voltage deviation value of the distributed photovoltaic power generation system connected to the distribution network is within the range of -10% to -5% and 5% to 10%, the distribution network voltage is in a yellow warning state (the distribution network is in an unsafe state); (3) When the frequency deviation value of the distributed photovoltaic power generation system connected to the distribution network line is between -2% and -1% and between 1% and 2%, the distribution network frequency is in a yellow warning state (the distribution network is in an unsafe state); (4) When the voltage deviation of the distributed photovoltaic power generation system connected to the distribution network is less than -10% or greater than 10%, the distribution network voltage is in a red warning state (the distribution network is in an extremely unsafe state); (5) When the frequency deviation value of the distributed photovoltaic power generation system connected to the distribution network line is less than -2% or greater than 2%, the distribution network frequency is in a red warning state (the distribution network is in an extremely unsafe state).

[0027] The distributed photovoltaic power generation system in this scheme is connected to the voltage and frequency state parameters of the distribution network line, and a distributed photovoltaic power generation system cut-out calculation model based on the operating status of the distribution network line is proposed. In the process of switching off, the existing distributed photovoltaic power generation system does not take into account the voltage, frequency and other state parameters of the access line, so that the distributed photovoltaic power generation system on the distribution line with excessive voltage and frequency is not switched off in time, which brings great challenges to the safe and stable operation of the distribution network. In this model, the probability of a distributed photovoltaic system being disconnected is determined by the degree to which the voltage and frequency of the distribution network lines exceed the standard values. The greater the degree to which the voltage and frequency of the distribution network lines exceed the standard values, the greater the probability that the distributed photovoltaic system on that line will be disconnected, thereby ensuring the safe and stable operation of the distribution network.

[0028] (4) According to the temperature of photovoltaic panels and converters, a distributed photovoltaic power generation system health status analysis model based on temperature distribution characteristics is constructed. On this basis, a cut-out calculation model based on the health status of distributed photovoltaic power generation system is proposed. Computational model The detailed construction process is as follows: 1) In a distributed photovoltaic power generation system cluster located in the same area, the photovoltaic panel temperatures are relatively similar. When the temperature of a photovoltaic panel differs significantly from the average temperature of the rest of the photovoltaic panels in the distributed photovoltaic power generation system cluster, it indicates that the photovoltaic panel is in poor health and should be promptly disconnected. To this end, the present invention uses the temperature distribution characteristics to construct a photovoltaic panel health status analysis model based on the deviation between the photovoltaic panel temperature of the distributed photovoltaic power generation system and the average temperature of the photovoltaic panels in the cluster. The calculation formulas of the photovoltaic panel health status analysis model are shown in Equations (3) and (4).

[0029] (3) (4) In equations (3) and (4), it is expected that Represents the average temperature of all photovoltaic panels in the distributed photovoltaic power generation system cluster, Indicates the Distributed photovoltaic power generation system The temperature of each photovoltaic panel, Indicates the The degree to which the photovoltaic panel temperature of a distributed photovoltaic power generation system deviates from the average value, represents the number of distributed photovoltaic power generation systems, Indicates the number of photovoltaic panels in a distributed photovoltaic power generation system.

[0030] For formula (4), The smaller the value, the The smaller the deviation of the photovoltaic panel temperature of a distributed photovoltaic power generation system from the average value, the better the health of the photovoltaic panel; The larger the value, the greater the deviation of the photovoltaic panel temperature from the average value, and the worse the health of the photovoltaic panel.

[0031] 2) The temperatures of the converters in distributed photovoltaic power generation systems in the same area are relatively similar. When the temperature of a distributed photovoltaic power generation system converter differs significantly from the average temperature of the converters in the distributed photovoltaic power generation system cluster, it indicates that the converter is in poor health and should be promptly disconnected. Based on the deviation between the temperature of the distributed photovoltaic power generation system converter and the average temperature of the converters in the distributed photovoltaic power generation system cluster, the temperature distribution characteristics are used to construct a converter health status analysis model. The converter health status analysis model is shown in Equations (5) and (6).

[0032] (5) (6) In the converter temperature distribution characteristics, it is expected that Represents the average temperature of the cluster converter of the distributed photovoltaic power generation system, Indicates the Distributed photovoltaic power generation system The temperature value of each converter, Indicates the The degree to which the converter temperature of a distributed photovoltaic power generation system deviates from the average temperature of the cluster, represents the number of distributed photovoltaic power generation systems, Indicates the number of converters in a distributed photovoltaic power generation system.

[0033] when When the value is large, it indicates that the temperature value of the distributed photovoltaic power generation system converter deviates greatly from the average temperature of the cluster converter, and the health status of the distributed photovoltaic power generation system converter is poor, and the distributed photovoltaic power generation system should be cut off in time; when When the value is small, it indicates that the temperature value of the distributed photovoltaic power generation system converter deviates slightly from the average temperature of the cluster converter, and the distributed photovoltaic power generation system converter is in good health.

[0034] Since photovoltaic panels and converters are the core components of a distributed photovoltaic power generation system and are also the most prone to failure, their health status represents the overall health of the distributed photovoltaic power generation system. This health status can be calculated using a distributed photovoltaic power generation system health analysis model. When a distributed photovoltaic power generation system is healthy, the likelihood of it being disconnected is low. However, when a distributed photovoltaic power generation system is subhealthy or faulty, the likelihood of it being disconnected is high. Therefore, the disconnection value can be calculated based on the health status of the distributed photovoltaic power generation system. The healthier the distributed photovoltaic power generation system, the smaller the disconnection value. Conversely, the worse the health of the distributed photovoltaic power generation system, the greater the likelihood of it being disconnected.

[0035] According to the national standard for determining the health status of distributed photovoltaic power generation systems, the present invention divides the health status of distributed photovoltaic power generation systems into healthy (temperature deviation value in the range of -10% to 10%), yellow warning zone (temperature deviation value in the range of -20% to -10% or 10% to 20%), and red warning zone (temperature deviation value less than -20% or greater than 20%), and assigns different cut-out coefficients according to the health status of the distributed photovoltaic power generation system. The worse the health status of the distributed photovoltaic power generation system, the larger the cut-out coefficient of the distributed photovoltaic power generation system, and the greater the possibility of the distributed photovoltaic being cut out.

[0036] 3) Based on the relationship between the health status of distributed photovoltaics and the possibility of being cut off, and based on the health status analysis model of photovoltaic panels and converters in distributed photovoltaic power generation systems, a cut-off calculation model based on the health status of distributed photovoltaic power generation systems is constructed. .

[0037] Building a computational model The calculation principle is as follows: when the temperature deviation between the photovoltaic panels and converters of the distributed photovoltaic power generation system and the average temperature of the photovoltaic panels and converters of the cluster system is within a reasonable range (the temperature deviation is between -10% and 10%), the photovoltaic panels and converters of the distributed photovoltaic power generation system are in a healthy state; when the temperature deviation between the photovoltaic panels and converters of the distributed photovoltaic power generation system and the average temperature of the photovoltaic panels and converters of the cluster system is in the yellow warning zone (the temperature deviation is between -20% and -10% or between 10% and 20%), the photovoltaic panels and converters of the distributed photovoltaic power generation system are in a sub-healthy state and need to be considered for switching out; when the temperature deviation between the photovoltaic panels and converters of the distributed photovoltaic power generation system and the average temperature of the photovoltaic panels and converters of the cluster system is in the red warning zone (the temperature deviation is less than -20% or greater than 20%), the photovoltaic panels and converters of the distributed photovoltaic power generation system are in a fault state and need to be switched out immediately. According to the above-mentioned switch-out calculation method based on the health status of the distributed photovoltaic power generation system, the switch-out calculation model based on the health status of the distributed photovoltaic power generation system is constructed as shown in formula (7).

[0038] (7) In formula (7), According to the A set of cut-out values ​​obtained by calculating the temperature deviation between the photovoltaic panels and the converter of the distributed photovoltaic power generation system; 、 、 and is the cut-out coefficient of the photovoltaic panels and converters in the distributed photovoltaic power generation system. The size of the cut-out coefficient needs to be determined through fault experiments of the photovoltaic panels and converters. No. Set of photovoltaic panel temperature values ​​of distributed photovoltaic power generation system, No. Set of temperature values ​​of the converter of the distributed photovoltaic power generation system.

[0039] (1) When the temperature deviation between the photovoltaic panels and the converter of the distributed photovoltaic power generation system is within a reasonable range (the temperature deviation is between -10% and 10%), the photovoltaic panels and converter of the distributed photovoltaic power generation system are in a healthy state, and the calculation model is cut out. The expression is: ; (2) When the temperature deviation of the photovoltaic panels of the distributed photovoltaic power generation system is in the yellow warning zone (the temperature deviation is between -20% and -10% or between 10% and 20%), the calculation model is cut out. The expression is: ; (3) When the temperature deviation of the inverter of the distributed photovoltaic power generation system is in the yellow warning zone (the temperature deviation is between -20% and -10% or between 10% and 20%), the calculation model is cut out. The expression is: ; (4) When the temperature deviation values ​​of the photovoltaic panels and the converter of the distributed photovoltaic power generation system are both in the yellow warning zone (the temperature deviation value is between -20% and -10% or between 10% and 20%), the distributed photovoltaic power generation system has a certain possibility of being cut off. The cut-off calculation model The expression is: ; (5) When the temperature deviation of the photovoltaic panel of the distributed photovoltaic power generation system is in the red warning zone (the temperature deviation is less than -20% or greater than 20%), and the inverter temperature is in a healthy state (the temperature deviation is between -10% and 10%), the calculation model is cut out. The expression is: ; (6) When the inverter temperature deviation value of the distributed photovoltaic power generation system is in the red warning zone (the temperature deviation value is less than -20% or greater than 20%), and the photovoltaic panel temperature is in a healthy state (the temperature deviation value is between -10% and 10%), the calculation model is cut out. The expression is: ; (7) When the temperature deviation of the photovoltaic panel of the distributed photovoltaic power generation system is in the red warning zone (the temperature deviation is less than -20% or greater than 20%), and the temperature deviation of the inverter is in the yellow warning zone (the temperature deviation is between -20% and -10% or between 10% and 20%), the calculation model is cut out. The expression is: ; (8) When the temperature deviation of the inverter of the distributed photovoltaic power generation system is in the red warning zone (the temperature deviation is less than -20% or greater than 20%), and the temperature deviation of the photovoltaic panel is in the yellow warning zone (the temperature deviation is between -20% and -10% or between 10% and 20%), the calculation model is cut out. The expression is: ; (9) When the temperature deviation between the photovoltaic panels and the inverter of the distributed photovoltaic power generation system is in the red warning zone (the temperature deviation is less than -20% or greater than 20%), the calculation model is cut out. The expression is: .

[0040] In the above equation, 、 、 and is the cut-out coefficient of the photovoltaic panels and converters in the distributed photovoltaic power generation system. The size of the cut-out coefficient can be determined by the statistical analysis results of the long-term operation status of the distributed photovoltaic power generation system cluster.

[0041] Specifically, according to the national standard for determining the health status of distributed photovoltaic power generation systems, the following interval divisions of distributed photovoltaic power generation systems can be obtained: (1) When the deviation between the temperature of the photovoltaic panels and converters of the distributed photovoltaic power generation system and the average temperature of the photovoltaic panels and converters of the cluster system is within a reasonable range (the temperature deviation is between -10% and 10%), the photovoltaic panels and converters of the distributed photovoltaic power generation system are in a healthy state; (2) When the deviation between the temperature of the photovoltaic panels of the distributed photovoltaic power generation system and the average temperature of the photovoltaic panels of the cluster system is in the yellow warning zone (the temperature deviation is between -20% and -10% or between 10% and 20%), the photovoltaic panels of the distributed photovoltaic power generation system are in a sub-healthy state and need to be considered for disconnection; (3) When the temperature deviation between the inverter of the distributed photovoltaic power generation system and the average temperature of the cluster system inverter is in the yellow warning zone (the temperature deviation is between -20% and -10% or between 10% and 20%), the inverter of the distributed photovoltaic power generation system is in a sub-healthy state and needs to be considered for shutdown; (4) When the deviation between the temperature value of the photovoltaic panels of the distributed photovoltaic power generation system and the average temperature of the photovoltaic panels of the cluster system is in the red warning zone (the temperature deviation is less than -20% or greater than 20%), the photovoltaic panels of the distributed photovoltaic power generation system are in a fault state and need to be cut out as soon as possible.

[0042] (5) When the temperature deviation between the inverter of the distributed photovoltaic power generation system and the average temperature of the cluster system inverter is in the red warning zone (the temperature deviation is less than -20% or greater than 20%), the inverter of the distributed photovoltaic power generation system is in a fault state and needs to be cut out as soon as possible.

[0043] This scheme proposes a switch-out calculation model based on the health status analysis model of distributed photovoltaic power generation system. At present, the disconnection of distributed photovoltaic power generation systems is completed by staff. The staff has a certain degree of randomness and subjectivity in the process of disconnecting distributed photovoltaic power generation systems, and does not consider the health status of the distributed photovoltaic power generation systems themselves, so that some distributed photovoltaic power generation systems in a fault state are not disconnected in time, affecting the safe and stable operation of the distributed photovoltaic power generation systems; Model In the process of cutting out the distributed photovoltaic power generation system, the model considers the degree to which the temperature of the photovoltaic panels and the converter deviates from the healthy state value. The greater the deviation, the greater the possibility of the distributed photovoltaic power generation system being cut out.

[0044] (5) Calculation model for cluster switch-out probability of distributed photovoltaic power generation system based on running time , a distributed photovoltaic power generation system switching calculation model based on the distribution network operation status , and a switch-out calculation model based on the health status of distributed photovoltaic power generation systems , the distributed photovoltaic power generation system cluster intelligent cut-out decision model is obtained by fusion. Specifically, the distributed photovoltaic power generation system cluster intelligent cut-out decision model needs to comprehensively consider three factors: the operating time of the distributed photovoltaic power generation system, the operating status of the distribution network, and the health status of the distributed photovoltaic power generation system. In order to reflect these three factors in the distributed photovoltaic power generation system cluster intelligent cut-out decision model, the above factors are assigned corresponding weights to comprehensively consider the relevant factors. The specific calculation process is shown in Equation (8).

[0045] (8) In formula (8), is the distributed photovoltaic power generation system that is cut out (the distributed photovoltaic power generation system with the largest cut-out value), For the Set of distributed photovoltaic power generation system cut-out function expressions, For the A distributed photovoltaic power generation system cut-out model based on the operating time, The first A distributed photovoltaic power generation system cut-out calculation model, Based on the A set of health status cut-out calculation models for distributed photovoltaic power generation systems, Switching out computational models for runtime The weight of Calculation model for the operation status of distribution network lines The weight of Calculation model for the health status of distributed photovoltaic power generation systems The weight of each model is determined according to the actual operating status of the distributed photovoltaic power generation system, but must meet For example, the health status of the distributed photovoltaic power generation system has a significant impact on the system switching out. In this case, the health status of the distributed photovoltaic power generation system can be switched out of the calculation model. Weight The weights of the other two cut-out models are set to 0.2 and 0.2 respectively. In practice, the specific values ​​of the weights need to be considered according to the actual situation of the project. Here is a simple example.

[0046] The expression of the distributed photovoltaic power generation system's cut-out function combines a cut-out model based on operating time, a cut-out calculation model based on the distribution network's operating status, and a cut-out calculation model based on the distributed photovoltaic power generation system's health status. By assigning different weights to these cut-out models, the cut-out value of the distributed photovoltaic power generation system can be calculated based on the expression of the distributed photovoltaic power generation system's cut-out function.

[0047] According to the above-mentioned distributed photovoltaic power generation system cut-out function expression, the cut-out value of each distributed photovoltaic power generation system can be calculated in real time. By selecting the distributed photovoltaic power generation system with the largest switch-out value in the distributed photovoltaic power generation system cluster for switch-out, an intelligent switch-out decision process of the distributed photovoltaic power generation system cluster can be realized.

[0048] Example 2: The study is conducted on the intelligent switching of a distributed photovoltaic power generation system cluster. The distributed photovoltaic power generation cluster consists of 9 distributed photovoltaic power generation systems. The operating time, health status parameters and distribution network line operating status parameters of each distributed photovoltaic power generation system are shown in Table 1.

[0049] Table 1 Cluster status parameters of distributed photovoltaic power generation system Status parameters Power Station 1 Power Station 2 Power Station 3 Power Station 4 Power Station 5 Power Station 6 Power Station 7 Power Station 8 Power Station 9 Run time 4h 7h 12h 6h 3h 2h 6h 5h 8h Line voltage 0.05 0.1 0 0.2 0.12 0.07 0.09 0.1 0.22 Line frequency 0.01 0.08 0.03 0.1 0.21 0.03 0.08 0.12 0.18 Photovoltaic panel temperature 41 40 41 41 42 40 41 40 49 Converter temperature 52 51 51 51 52 58 51 50 51 According to the distributed photovoltaic power generation system cluster cut-out model calculation formula (8), the distributed photovoltaic power generation system cluster in Table 1 is calculated. During the calculation process, The value is 5, the duration is cut out The value of is 1, and The value of is 10, and The value of is 20, and The value of is 0.5, and The value of is 1, According to the above parameter values, the calculation process of the distributed photovoltaic power generation system cluster cut-out model is as follows: Figure 2 、 Figure 3 and Figure 4 shown.

[0050] in, Figure 2This is the distributed photovoltaic power generation system cluster intelligent cut-out strategy interface. By selecting the "Data Entry" button in the cut-out model interface, the distributed photovoltaic power generation system cluster data can be read into the cluster intelligent cut-out model. Then, clicking the "Intelligent Cut-out Calculation" button in the interface will invoke the proposed method to calculate the distributed photovoltaic power generation system cluster data.

[0051] Figure 3 This is a calculation program for the intelligent switch-out strategy of distributed photovoltaic power generation system clusters. Through this program, the switch-out value of each distributed photovoltaic power station can be accurately calculated, and then the distributed photovoltaics are sorted according to the switch-out value of the distributed photovoltaic power station. The photovoltaic power station with the largest switch-out value is switched out first.

[0052] Figure 4 This is the calculation result diagram of the distributed photovoltaic power generation system cluster intelligent cut-out. Figure 4 The distributed PV power plants are ranked by their cut-out values: Power Plant 9 > Power Plant 3 > Power Plant 5 > Power Plant 6 > Power Plant 4 > Power Plant 2 > Power Plant 8 > Power Plant 7 > Power Plant 1. The distributed PV discovery system with the largest cut-out value is cut out first. The calculation results show that distributed PV power plant 9 is the first to be cut out.

Claims

1. A cluster intelligent cut-out strategy for a regional distributed photovoltaic power generation system, characterized in that: The steps include: S1. Using the communication system to collect meteorological monitoring station data and distributed photovoltaic power generation system cluster operation status data at a set time resolution; S2. According to the relationship between the continuous operation time of the distributed photovoltaic power generation system cluster and the switch-out decision, a distributed photovoltaic power generation system cluster switch-out calculation model based on the operation time is constructed; S3, according to the voltage and frequency of the line at the access point of the distributed photovoltaic power generation system, construct a distributed photovoltaic power generation system cut-out calculation model based on the operating status of the distribution network; S4. According to the temperature of the photovoltaic panel and the temperature of the converter, a health status analysis model based on the distributed photovoltaic power generation system is constructed, and then a cut-out calculation model based on the health status of the distributed photovoltaic power generation system is constructed; S5, integrating the switch-out calculation models constructed in S2, S3 and S4, to obtain the distributed photovoltaic power generation system cluster intelligent switch-out decision model.

2. According to claim 1, a regional distributed photovoltaic power generation system cluster intelligent cut-out strategy is characterized in that: The distributed photovoltaic power generation system cluster operating status data includes the photovoltaic system continuous operation time, photovoltaic system power, photovoltaic system current, voltage and frequency of the line at the access point of the distributed photovoltaic power generation system, photovoltaic panel temperature and converter temperature.

3. According to claim 1, a cluster intelligent switching-out strategy for a regional distributed photovoltaic power generation system is characterized in that: In S2, the distributed photovoltaic power generation system cluster cut-out calculation model based on the operating time Specifically expressed as: ； In the formula, For the The operating time of a distributed photovoltaic power generation system, in hours. is the number of power generation systems in the distributed photovoltaic power generation system cluster, is the average operating time of the distributed photovoltaic power generation system cluster, is the first The cut-out value of the distributed photovoltaic power generation system, is the duration cut-out factor of the distributed photovoltaic power generation system.

4. According to claim 1, a cluster intelligent switching-out strategy for a regional distributed photovoltaic power generation system is characterized in that: In S3, the distributed photovoltaic power generation system cut-out calculation model based on the distribution network operation status Specifically expressed as: ； In the formula, According to The cut-out value is calculated based on the frequency and voltage values ​​at the access point of the distributed photovoltaic power generation system. Indicates The frequency value at the access point of the distributed photovoltaic power generation system, Indicates The voltage value at the access point of the distributed photovoltaic power generation system, According to The cut-out value is calculated based on the frequency and voltage values ​​at the access point of the distributed photovoltaic power generation system. When the voltage of the distribution network line is in yellow warning, the cut-out coefficient is in the range of -10% to -5% and 5% to 10%. When the distribution network line voltage is in red warning, the voltage deviation value exceeds the cut-out coefficient of 10%; When the frequency of the distribution network line is in yellow warning, the frequency deviation value is in the range of -2% to -1% and 1% to 2%. It is the cut-out coefficient when the frequency deviation value is less than -2% or greater than 2% when the distribution network line frequency is in red warning.

5. According to claim 1, a cluster intelligent switching-out strategy for a regional distributed photovoltaic power generation system is characterized in that: The S4 comprises the following steps: S41, constructing a photovoltaic panel health status analysis model based on the photovoltaic panel temperature of the distributed photovoltaic power generation system and utilizing the temperature distribution characteristics; S42, constructing a converter health status analysis model based on the converter temperature of the distributed photovoltaic power generation system and utilizing the temperature distribution characteristics; S43. According to the photovoltaic panel health status analysis model and the converter health status analysis model, a cut-out calculation model based on the health status of the distributed photovoltaic power generation system is constructed.

6. A cluster intelligent cut-out strategy for a regional distributed photovoltaic power generation system according to claim 5, characterized in that: The specific expression of the photovoltaic panel health status analysis model is: ； ； In the formula, expectation Represents the average temperature of photovoltaic panels in the distributed photovoltaic power generation system cluster, Indicates Distributed photovoltaic power generation system The temperature of the photovoltaic panel, Indicates The degree to which the photovoltaic panel temperature of a distributed photovoltaic power generation system deviates from the average value, represents the number of distributed photovoltaic power generation systems, Represents the number of photovoltaic panels in a distributed photovoltaic power generation system.

7. A cluster intelligent cut-out strategy for a regional distributed photovoltaic power generation system according to claim 5, characterized in that: The converter health status analysis model is specifically expressed as: ； ； In the formula, expectation represents the average temperature of the converter of the distributed photovoltaic power generation system cluster, Indicates Distributed photovoltaic power generation system The temperature of the converter, Indicates The degree to which the converter temperature of a distributed photovoltaic power generation system deviates from the average value, represents the number of distributed photovoltaic power generation systems, Represents the number of converters in a distributed photovoltaic power generation system.

8. A cluster intelligent switching-out strategy for a regional distributed photovoltaic power generation system according to claim 6, characterized in that: The switch-out calculation model based on the health status of the distributed photovoltaic power generation system Specifically expressed as: ； In the formula, According to The cut-out value is calculated based on the photovoltaic panel temperature and converter temperature of the distributed photovoltaic power generation system. , , and is the cut-out coefficient of the photovoltaic panels and converters in the distributed photovoltaic power generation system. The size of the cut-out coefficient needs to be determined through fault experiments of the photovoltaic panels and converters. No. Set of photovoltaic panel temperature values ​​of distributed photovoltaic power generation system, No. Set of temperature values ​​of the inverter of the distributed photovoltaic power generation system.

9. The cluster intelligent switching-out strategy of a regional distributed photovoltaic power generation system according to claim 1, characterized in that: In S5, the specific expression of the distributed photovoltaic power generation system cluster intelligent switching decision model is: ； In the formula, For the distributed photovoltaic power generation system to be cut out, For the Set the cut-out function value of the distributed photovoltaic power generation system, for The weight of for The weight of for The weight of .

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