Centralized photovoltaic inverter high and low voltage safety analysis monitoring method

Abstract

This invention discloses a method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters. This invention relates to the field of photovoltaic inverter technology and solves the problem that when an anomaly is detected in a circuit, maintenance personnel need to check each parameter one by one, lacking the ability to accurately pinpoint the abnormal parameter. This invention constructs parameter polygons and area ranges using multi-type circuit data, and combines this with high-low voltage ratio verification to form a quantitative standard, avoiding the limitations of single-parameter monitoring and improving the comprehensiveness and accuracy of benchmark settings. In real-time monitoring, the abnormal circuit is quickly located by comparing the area ratio with the range, clearly identifying whether the anomaly belongs to the high-voltage or low-voltage circuit, reducing misjudgments and omissions. Based on the following characteristics during the trial operation phase and the comparison of parameter trends within the monitoring period, the abnormal parameter is accurately pinpointed, providing maintenance personnel with clear repair directions, shortening fault handling time, ensuring the safe and stable operation of the inverter's high and low voltage circuits, and improving the overall reliability of the photovoltaic system.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic inverter technology, specifically a method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters. Background Technology

[0002] Against the backdrop of the rapid development of the new energy industry, centralized photovoltaic inverters, as the core power conversion equipment of photovoltaic power plants, directly determine the power generation efficiency and safety level of the entire photovoltaic system through their operational stability. Centralized photovoltaic inverters typically involve the coordinated operation of high-voltage circuits (e.g., 1500V DC side) and low-voltage circuits (e.g., 600V AC side). The parameter matching and operational status monitoring of the high and low voltage circuits are crucial for ensuring equipment safety. With the increasing scale and capacity of photovoltaic power plants, the operating environment of the inverter's high and low voltage circuits is becoming increasingly complex. Factors such as voltage fluctuations, load changes, and component aging can all cause circuit parameters to deviate from normal ranges, leading to equipment failures, power generation interruptions, and even safety accidents.

[0003] Currently, the industry primarily uses a single-parameter threshold method for monitoring the high and low voltage circuits of centralized photovoltaic inverters. This involves setting fixed thresholds for independent parameters such as voltage, current, and power, and triggering an alarm when the monitored value exceeds the threshold. However, this monitoring method has significant limitations: Firstly, there is a strong correlation between various parameters during the operation of a photovoltaic inverter, and a single parameter threshold cannot reflect the overall operating status of the circuit, easily leading to false alarms or missed alarms. For example, if one parameter slightly exceeds the standard while other related parameters are normal, it may be misjudged as an anomaly; conversely, if multiple parameters are close to the threshold but not exceeding it, potential risks may be overlooked. Secondly, existing technologies lack quantitative analysis of the synergistic relationship between high and low voltage circuits, making it impossible to determine the overall health of the system through the matching of high and low voltage parameters. When the parameters of the high-voltage and low-voltage circuits are individually within the thresholds but the ratio is abnormal, it is difficult to identify hidden circuit faults or parameter drift problems in a timely manner.

[0004] Furthermore, traditional monitoring methods suffer from inefficiency in fault tracing. When a circuit anomaly is detected, maintenance personnel must check each parameter one by one, lacking the ability to accurately pinpoint the abnormal parameter, resulting in long fault handling cycles and high maintenance costs. Therefore, there is an urgent need for a safety analysis and monitoring method that can comprehensively consider the correlation characteristics of multiple parameters in high and low voltage circuits and achieve accurate anomaly identification and fault tracing to meet the needs of efficient and reliable operation monitoring for centralized photovoltaic inverters. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a centralized photovoltaic inverter high and low voltage safety analysis and monitoring method, which solves the problem that when an abnormal circuit is detected, maintenance personnel need to check each parameter one by one, lacking the ability to accurately pinpoint the abnormal parameter.

[0006] To achieve the above objectives, the present invention provides a method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters, comprising the following steps: Step 1: Confirm the circuit data generated during the trial operation of the high-voltage and low-voltage circuits of the centralized photovoltaic inverter. Based on the confirmed circuit data of different types, generate high-voltage circuit standards and low-voltage circuit standards associated with the associated voltages. Then, verify the ratio of the high-voltage circuit standards and low-voltage circuit standards to confirm the corresponding ratio range of the high-voltage and low-voltage circuits under the associated voltages. The specific method is as follows: Confirm the circuit data associated with the trial operation phase, lock several sets of circuit data associated with the same high voltage, determine the total number of types G in the circuit data, construct a set of reference standards, randomly select a point as the center point, and sort G sets of extension lines in a circular array with the center point as the center point. The starting point of each extension line is the center point, and the length of each set of extension lines is the same. Connect the endpoints of adjacent extension lines to produce the parameter polygons associated with the G sets of extension lines. Within the reference polygon, each set of extension lines is randomly bound to different types of loop data, and a measurement standard is set for each set of extension lines. The measurement standards for each set of extension lines are different. Based on the set measurement standards, the measurement points associated with the corresponding loop data and the corresponding extension lines are confirmed. The measurement points of multiple sets of loop data associated at the same time are confirmed, and the confirmed measurement points are connected to confirm the built-in polygon associated with multiple sets of loop data at the corresponding time. The built-in polygon is a reference standard associated with a set of time. The reference standards associated with different times belonging to the same high voltage state are identified, and the minimum and maximum areas are identified from the identified reference standards to generate the area interval associated with the corresponding high voltage, which is denoted as the high voltage area interval.

[0007] The specific method for confirming the low-voltage circuit standard is as follows: The same low voltage associated with the same high voltage is identified, and the same determination method for the area range of the same high voltage is used to identify the reference standard for several sets of loop data generated by the same low voltage at different times. Combined with the reference polygon, the minimum area and the maximum area associated with the corresponding reference standard are identified. Therefore, the area range associated with the corresponding low voltage is identified and recorded as the low voltage area range.

[0008] The specific method for verifying the ratio between the high-voltage circuit standard and the low-voltage circuit standard is as follows: Determine the high-voltage area intervals [MJ1, MJ2] associated with the same high voltage, and then confirm the low-voltage area intervals [MM1, MM2] associated with the same low voltage corresponding to the same high voltage. Use the ratios (MJ1:MM1), (MJ1:MM2), (MJ2:MM1), and (MJ2:MM2) to confirm four sets of area ratios. From the confirmed four sets of area ratios, determine the minimum and maximum values. Based on the confirmed minimum and maximum values, generate the corresponding high-voltage-low-voltage ratio intervals and record them. The different "high voltage - low voltage" ratio ranges were confirmed and recorded sequentially. Step 2: Monitor the high and low voltage operating parameters of the centralized photovoltaic inverter in real time, and based on the recorded ratio range, assess in real time whether there are any abnormalities in the high and low voltage operation. If an abnormality is found, identify the abnormal circuit; if no abnormality is found, continue monitoring. The specific method is as follows: Determine the different operating parameters associated with different high and low voltage circuits, and in conjunction with the constructed reference polygons, confirm the location of the corresponding operating parameters in real time. Simultaneously confirm the built-in polygon BX1 associated with the high voltage circuit and the built-in polygon BX2 associated with the low voltage circuit at the corresponding time. Then confirm the area parameters MX1 and MX2 of BX1 and BX2. Then perform ratio processing on MX1 and MX2 to confirm the area ratio, where the area ratio = MX1:MX2. Determine the two sets of voltage values ​​for high and low voltage. From the recorded ratio range, confirm the ratio range of the same high and low voltage. Monitor in real time whether the area ratio generated at the corresponding time belongs to the ratio range. If it does, no processing is required. If not, perform anomaly verification. The area parameter MX1 ​​of the high-voltage circuit at the corresponding time is compared and verified with the corresponding high-voltage area interval. Then, the area parameter MX2 of the low-voltage circuit at the corresponding time is compared and verified with the corresponding low-voltage area interval. If MX1 ∈ high-voltage area interval, MX2 ∈ low-voltage area interval. If the low-voltage area is an abnormality, it indicates an anomaly in the low-voltage circuit. The low-voltage circuit will be marked as an abnormal circuit. If MX1... If the high-voltage area range and MX2 ∈ the low-voltage area range, it indicates an anomaly in the high-voltage circuit. The high-voltage circuit is then marked as an abnormal circuit. If MX1 High voltage area range, MX2 In the low-voltage area, both the high-voltage circuit and the low-voltage circuit are marked as abnormal circuits; Step 3: For the marked abnormal loops, confirm the tracking characteristics of the corresponding loops during the trial operation phase from the historical process, then determine a set of monitoring periods. Within this monitoring period, determine the tracking characteristics of various operating parameters of the abnormal loop, and through comprehensive comparison and verification, lock down and display the abnormal parameter items. The specific method is as follows: Based on the identified abnormal circuit, the voltage parameter associated with the abnormal circuit is recorded as the main parameter. The parameter data generated by the circuit during the trial operation phase is determined, the change process of the main parameter is confirmed, and the change trend ZH of adjacent time moments is confirmed from the change process. The parameter value of the main parameter at the previous time moment is denoted as CS1, and the parameter value at the next time moment is denoted as CS2. The change trend ZH = CS2 - CS1 is determined. The change trend BH of other parameter items at the same time moment is confirmed simultaneously. The limit value XD generated at the corresponding adjacent time moment is determined by using ZH ÷ BH = XD. Several sets of limit values ​​XD generated are confirmed in sequence, and the maximum and minimum values ​​are selected from them to generate the following interval associated with the corresponding parameter items. Then, the following intervals generated between different parameter items and the main parameter item are confirmed in sequence. A set of monitoring cycles is defined, which is a preset cycle, generally 10 minutes. The operating parameters of the abnormal circuit are monitored within the monitoring cycle, and the voltage parameter is recorded as the main parameter item. The same confirmation method as the following interval is used to confirm the following interval generated by other parameter items and the main parameter item within the monitoring cycle. The following interval confirmed during the trial operation is recorded as the standard interval, and the following interval confirmed within the monitoring cycle is recorded as the monitoring interval. If the monitoring interval ∈ the standard interval, no processing is required. If the monitoring interval ∉ the standard interval, the corresponding parameter item is recorded as an abnormal parameter item. If the monitoring intervals of all parameter items do not belong to the corresponding standard intervals, the corresponding main parameter item is directly recorded as an abnormal parameter item. The marked abnormal parameter items will then be displayed.

[0009] This invention provides a method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters. Compared with existing technologies, it has the following advantages: The standard is scientifically and accurately constructed: parameter polygons and area ranges are constructed by using multi-type loop data, and quantitative standards are formed by combining high and low voltage ratio verification, which avoids the limitations of single parameter monitoring and improves the comprehensiveness and accuracy of benchmark setting. Highly efficient and accurate anomaly identification: In real-time monitoring, abnormal circuits can be quickly located by comparing area ratios with intervals, clarifying the attribution of high-voltage or low-voltage circuit anomalies, and reducing misjudgments and missed judgments. Clear and convenient fault tracing: Based on the comparison of the characteristics followed during the trial operation phase and the parameter trends within the monitoring period, abnormal parameter items can be accurately identified, providing clear repair directions for operation and maintenance personnel, shortening fault handling time, ensuring the safe and stable operation of the inverter's high and low voltage circuits, and improving the overall reliability of the photovoltaic system. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0011] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] Please see Figure 1 This application provides a method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters, including the following steps: Step 1: Confirm the circuit data generated during the trial operation of the high-voltage and low-voltage circuits of the centralized photovoltaic inverter. Based on the confirmed circuit data of different types, generate high-voltage circuit standards and low-voltage circuit standards associated with the associated voltages. Then, verify the ratio of the high-voltage circuit standards and low-voltage circuit standards to confirm the ratio range of the corresponding high-voltage and low-voltage circuits under the associated voltage. Specifically, the different types of circuit data include voltage data, current data, power data, frequency data, and power factor data. Each type of circuit data is associated with a set of measurement standards. Under normal operating conditions, the high voltage of 1500V corresponds to the low voltage of 600V. The multiple parameters associated with the high voltage fluctuate in a stable state, and the multiple parameters associated with the low voltage also fluctuate in a stable state. By combining the fluctuation characteristics associated with the two, the numerical standards of the two circuits under the associated voltage can be effectively confirmed, thereby confirming the corresponding ratio range. The specific method for confirming the high-voltage circuit standard is as follows: Confirm the circuit data associated with the trial operation phase, lock several sets of circuit data associated with the same high voltage, determine the total number of types G in the circuit data, construct a set of reference standards, randomly select a point as the center point, and sort G sets of extension lines in a circular array with the center point as the center point. The starting point of each extension line is the center point, and the length of each set of extension lines is the same. Connect the endpoints of adjacent extension lines to produce the parameter polygons associated with the G sets of extension lines. Within the reference polygon, each set of extension lines is randomly bound to different types of loop data, and a measurement standard is set for each set of extension lines. The measurement standards for each set of extension lines are different. Based on the set measurement standards, the measurement points associated with the corresponding loop data and the corresponding extension lines are confirmed. The measurement points of multiple sets of loop data associated at the same time are confirmed, and the confirmed measurement points are connected to confirm the built-in polygon associated with multiple sets of loop data at the corresponding time. The built-in polygon is a reference standard associated with a set of time. The reference standards associated with different times belonging to the same high voltage state are identified, and the minimum and maximum areas are identified from the identified reference standards to generate the area range associated with the corresponding high voltage, which is denoted as the high voltage area range. Specifically, the proposed loop data includes voltage data, current data, power data, frequency data, and power factor data. Under the high voltage of 1500V, different loop data are associated with different times. Combined with the corresponding reference polygon, the corresponding measurement points are identified on each set of extension lines. Then, the corresponding measurement points are connected to identify the measurement polygons generated between the corresponding measurement points. The measurement polygons have an area value, so different measurement polygons at different times have different area values. This area range can be simplified into a fluctuation range between multiple values. The comprehensive ratio can be determined based on the corresponding area range, which facilitates subsequent synchronous monitoring on both high and low voltage sides. The specific method for confirming the low-voltage circuit standard is as follows: Confirm the same low voltage associated with the same high voltage (each group of different high voltages is associated with a group of low voltages, and the voltage parameters of this group are all preset values, which are determined in advance by relevant personnel), and use the same determination method for the area range of the same high voltage to confirm the reference standard for several groups of loop data generated by the same low voltage at different times. Combined with the reference polygon, confirm the minimum area and the maximum area associated with the corresponding reference standard. Therefore, confirm the area range associated with the corresponding low voltage, which is recorded as the low voltage area range. The specific method for verifying the ratio between the high-voltage circuit standard and the low-voltage circuit standard is as follows: Determine the high-voltage area intervals [MJ1, MJ2] associated with the same high voltage, and then confirm the low-voltage area intervals [MM1, MM2] associated with the same low voltage corresponding to the same high voltage. Use the ratios (MJ1:MM1), (MJ1:MM2), (MJ2:MM1), and (MJ2:MM2) to confirm four sets of area ratios. From the confirmed four sets of area ratios, determine the minimum and maximum values. Based on the confirmed minimum and maximum values, generate the corresponding high-voltage-low-voltage ratio intervals and record them. The different "high voltage - low voltage" ratio ranges were confirmed and recorded sequentially. Specifically, there is a set standard for both high voltage and low voltage. When the high voltage is 1500V, the low voltage must be 600V for operation. Under the same operating conditions of other high voltages and low voltages, the corresponding ratio ranges can also be confirmed and recorded in turn. Step 2: Monitor the high and low voltage operating parameters of the centralized photovoltaic inverter in real time, and evaluate in real time whether there are any abnormalities in the high and low voltage operation based on the recorded ratio range. If there is an abnormality, identify the abnormal circuit; if there is no abnormality, continue monitoring. The specific methods for assessing whether there are any abnormalities in the operation of high and low voltage systems are as follows: Determine the different operating parameters associated with different high and low voltage circuits, and in conjunction with the constructed reference polygons, confirm the location of the corresponding operating parameters in real time. Simultaneously confirm the built-in polygon BX1 associated with the high voltage circuit and the built-in polygon BX2 associated with the low voltage circuit at the corresponding time. Then confirm the area parameters MX1 and MX2 of BX1 and BX2. Then perform ratio processing on MX1 and MX2 to confirm the area ratio, where the area ratio = MX1:MX2. Determine the two sets of voltage values ​​for high and low voltage. From the recorded ratio range, confirm the ratio range of the same high and low voltage. Monitor in real time whether the area ratio generated at the corresponding time belongs to the ratio range. If it does, no processing is required. If not, perform anomaly verification. The area parameter MX1 ​​of the high-voltage circuit at the corresponding time is compared and verified with the corresponding high-voltage area interval (the area interval associated with high voltage). Then, the area parameter MX2 of the low-voltage circuit at the corresponding time is compared and verified with the corresponding low-voltage area interval (the area interval associated with low voltage). If MX1 ∈ high-voltage area interval, MX2 ∈ low-voltage area interval. If the low-voltage area is an abnormality, it indicates an anomaly in the low-voltage circuit. The low-voltage circuit will be marked as an abnormal circuit. If MX1... If the high-voltage area range and MX2 ∈ the low-voltage area range, it indicates an anomaly in the high-voltage circuit. The high-voltage circuit is then marked as an abnormal circuit. If MX1 High voltage area range, MX2 In the low-voltage area, both the high-voltage circuit and the low-voltage circuit are marked as abnormal circuits; Specifically, within the normal voltage range, the corresponding circuit operates in a relatively stable state during normal operation. That is, after multiple parameters are quantified, they correspond to the corresponding area characteristics. From the corresponding area characteristics, the area range between the corresponding areas is confirmed. Based on the comprehensive verification of the area range, it is possible to effectively identify whether the corresponding circuit belongs to a normal circuit, thereby marking abnormal circuits, evaluating abnormal parameter items based on abnormal states, and outputting the results in a timely manner to facilitate timely maintenance by relevant operators. Step 3: For the marked abnormal loop, confirm the following characteristics of the corresponding loop during the trial operation phase from the historical process, then determine a set of monitoring periods, determine the following characteristics of each operating parameter of the abnormal loop within this monitoring period, and lock the abnormal parameter items and display them by comprehensively comparing and verifying the process. The specific method for locking abnormal parameter items is as follows: Based on the identified abnormal circuit, the voltage parameter associated with the abnormal circuit is recorded as the main parameter. The parameter data generated by the circuit during the trial operation phase is determined, the change process of the main parameter is confirmed, and the change trend ZH of adjacent time moments is confirmed from the change process. The parameter value of the main parameter at the previous time moment is denoted as CS1, and the parameter value at the next time moment is denoted as CS2. The change trend ZH = CS2 - CS1 is determined. The change trend BH of other parameter items at the same time moment is confirmed simultaneously. The limit value XD generated at the corresponding adjacent time moment is determined by using ZH ÷ BH = XD. Several sets of limit values ​​XD generated are confirmed in sequence, and the maximum and minimum values ​​are selected from them to generate the following interval associated with the corresponding parameter items. Then, the following intervals generated between different parameter items and the main parameter item are confirmed in sequence. A set of monitoring cycles is defined, which is a preset cycle, generally 10 minutes. The operating parameters of the abnormal circuit are monitored within the monitoring cycle, and the voltage parameter is recorded as the main parameter item. The same confirmation method as the following interval is used to confirm the following interval generated by other parameter items and the main parameter item within the monitoring cycle. The following interval confirmed during the trial operation is recorded as the standard interval, and the following interval confirmed within the monitoring cycle is recorded as the monitoring interval. If the monitoring interval ∈ the standard interval, no processing is required. If the monitoring interval ∉ the standard interval, the corresponding parameter item is recorded as an abnormal parameter item (excluding the main parameter item). If the monitoring intervals of all parameter items do not belong to the corresponding standard intervals, the corresponding main parameter item is directly recorded as an abnormal parameter item. And display the marked abnormal parameter items; Specifically, based on the comparison of the characteristics followed during the trial operation phase and the parameter trends during the monitoring period, abnormal parameter items can be accurately identified, providing clear maintenance directions for operation and maintenance personnel, shortening fault handling time, ensuring the safe and stable operation of the inverter's high and low voltage circuits, and improving the overall reliability of the photovoltaic system.

[0013] Some of the data in the above formulas are numerical calculations with dimensions removed, and the contents not described in detail in this specification are all prior art known to those skilled in the art.

[0014] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters, characterized in that, Includes the following steps: Step 1: Confirm the circuit data generated by the high-voltage and low-voltage circuits of the centralized photovoltaic inverter during the trial operation phase. Based on the confirmed circuit data of different types, generate high-voltage circuit standards and low-voltage circuit standards associated with the associated voltages. Verify the ratio of the high-voltage circuit standards and low-voltage circuit standards to confirm the ratio range of the corresponding high-voltage circuits and low-voltage circuits under the associated voltages. Step 2: Monitor the high and low voltage operating parameters of the centralized photovoltaic inverter in real time, and evaluate in real time whether there are any abnormalities in the high and low voltage operation based on the recorded ratio range. If there is an abnormality, identify the abnormal circuit; if there is no abnormality, continue monitoring. Step 3: For the marked abnormal loop, confirm the following characteristics of the corresponding loop during the trial operation phase from the historical process, then determine a set of monitoring periods, determine the following characteristics of various operating parameters of the abnormal loop within this monitoring period, and lock down and display the abnormal parameter items through comprehensive comparison and verification process.

2. The method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters according to claim 1, characterized in that, In step one, the specific method for confirming the high-voltage circuit standard is as follows: Confirm the circuit data associated with the trial operation phase, lock several sets of circuit data associated with the same high voltage, determine the total number of types G in the circuit data, construct a set of reference standards, randomly select a point as the center point, and sort G sets of extension lines in a circular array with the center point as the center point. The starting point of each extension line is the center point, and the length of each set of extension lines is the same. Connect the endpoints of adjacent extension lines to produce the parameter polygons associated with the G sets of extension lines. Within the reference polygon, each set of extension lines is randomly bound to different types of loop data, and a measurement standard is set for each set of extension lines. The measurement standards for each set of extension lines are different. Based on the set measurement standards, the measurement points associated with the corresponding loop data and the corresponding extension lines are confirmed. The measurement points of multiple sets of loop data associated at the same time are confirmed, and the confirmed measurement points are connected to confirm the built-in polygon associated with multiple sets of loop data at the corresponding time. The built-in polygon is a reference standard associated with a set of time. The reference standards associated with different times belonging to the same high voltage state are identified, and the minimum and maximum areas are identified from the identified reference standards to generate the area interval associated with the corresponding high voltage, which is denoted as the high voltage area interval.

3. The method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters according to claim 2, characterized in that, In step one, the specific method for confirming the low-voltage circuit standard is as follows: The same low voltage associated with the same high voltage is identified, and the same determination method for the area range of the same high voltage is used to identify the reference standard for several sets of loop data generated by the same low voltage at different times. Combined with the reference polygon, the minimum area and the maximum area associated with the corresponding reference standard are identified. Therefore, the area range associated with the corresponding low voltage is identified and recorded as the low voltage area range.

4. The method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters according to claim 3, characterized in that, In step one, the specific method for verifying the ratio between the high-voltage circuit standard and the low-voltage circuit standard is as follows: Determine the high-voltage area intervals [MJ1, MJ2] associated with the same high voltage, and then confirm the low-voltage area intervals [MM1, MM2] associated with the same low voltage corresponding to the same high voltage. Use the ratios (MJ1:MM1), (MJ1:MM2), (MJ2:MM1), and (MJ2:MM2) to confirm four sets of area ratios. From the confirmed four sets of area ratios, determine the minimum and maximum values. Based on the confirmed minimum and maximum values, generate the corresponding high-voltage-low-voltage ratio intervals and record them. The different "high voltage - low voltage" ratio ranges were confirmed and recorded sequentially.

5. The method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters according to claim 1, characterized in that, In step two, the specific method for assessing whether there are any abnormalities in the operation of high and low voltage systems is as follows: Determine the different operating parameters associated with different high and low voltage circuits, and in conjunction with the constructed reference polygons, confirm the location of the corresponding operating parameters in real time. Simultaneously confirm the built-in polygon BX1 associated with the high voltage circuit and the built-in polygon BX2 associated with the low voltage circuit at the corresponding time. Then confirm the area parameters MX1 and MX2 of BX1 and BX2. Then perform ratio processing on MX1 and MX2 to confirm the area ratio, where the area ratio = MX1:MX2. Determine the two sets of voltage values ​​for high and low voltage. From the recorded ratio range, confirm the ratio range of the same high and low voltage. Monitor in real time whether the area ratio generated at the corresponding time belongs to the ratio range. If it does, no processing is required. If not, perform anomaly verification. The area parameter MX1 ​​of the high-voltage circuit at the corresponding time is compared and verified with the corresponding high-voltage area interval. Then, the area parameter MX2 of the low-voltage circuit at the corresponding time is compared and verified with the corresponding low-voltage area interval. If MX1 ∈ high-voltage area interval, MX2 ∈ low-voltage area interval. If the low-voltage area is an abnormality, it indicates an anomaly in the low-voltage circuit. The low-voltage circuit will be marked as an abnormal circuit. If MX1... If the high-voltage area range and MX2 ∈ the low-voltage area range, it indicates an anomaly in the high-voltage circuit. The high-voltage circuit is then marked as an abnormal circuit. If MX1 High voltage area range, MX2 In the low-voltage area, both the high-voltage circuit and the low-voltage circuit are marked as abnormal circuits.

6. The method for high and low voltage safety analysis and monitoring of centralized photovoltaic inverters according to claim 1, characterized in that, In step three, the specific method for locking the abnormal parameter item is as follows: Based on the identified abnormal circuit, the voltage parameter associated with the abnormal circuit is recorded as the main parameter. The parameter data generated by the circuit during the trial operation phase is determined, the change process of the main parameter is confirmed, and the change trend ZH of adjacent time moments is confirmed from the change process. The parameter value of the main parameter at the previous time moment is denoted as CS1, and the parameter value at the next time moment is denoted as CS2. The change trend ZH = CS2 - CS1 is determined. The change trend BH of other parameter items at the same time moment is confirmed simultaneously. The limit value XD generated at the corresponding adjacent time moment is determined by using ZH ÷ BH = XD. Several sets of limit values ​​XD generated are confirmed in sequence, and the maximum and minimum values ​​are selected from them to generate the following interval associated with the corresponding parameter items. Then, the following intervals generated between different parameter items and the main parameter item are confirmed in sequence. A set of monitoring cycles is defined, with a preset cycle typically set to 10 minutes. Various operating parameters of the abnormal circuit are monitored within these cycles, and the voltage parameter is recorded as the main parameter. Using the same confirmation method as for the following intervals, the following intervals generated by other parameters and the main parameter within the monitoring cycle are confirmed. The following intervals confirmed during the trial operation phase are recorded as the standard intervals, and the following intervals confirmed within the monitoring cycle are recorded as the monitoring intervals. If the monitoring interval ∈ the standard interval, no processing is required; otherwise, the monitoring interval... If the monitoring interval of all parameter items does not belong to the corresponding standard interval, then the corresponding main parameter item is directly recorded as an abnormal parameter item. The marked abnormal parameter items will then be displayed.

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