Method and system for determining the cause of high voltage in a provincial power grid with a high proportion of new energy

Abstract

The application discloses a kind of high proportion new energy provincial power grid voltage is high reason determination method, including obtaining the data information of target high proportion new energy provincial power grid;Transformer gear setting abnormality is judged, reactive compensation link abnormality is judged, lower level power grid reactive power is sent back to abnormality and judged, unit phase lead capability utilization abnormality is judged and the determination of capacitive reactive surplus influence abnormality;According to the obtained determination result is comprehensively considered, completes the voltage of target high proportion new energy provincial power grid is high reason determination.The application also discloses a kind of system for realizing the voltage of high proportion new energy provincial power grid is high reason determination method.The application not only realizes the voltage of high proportion new energy provincial power grid is high reason determination, and higher reliability, better accuracy.

Description

Technical Field

[0001] This invention belongs to the field of electrical automation, specifically relating to a method and system for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources. Background Technology

[0002] With economic and technological development and the improvement of people's living standards, electricity has become an indispensable secondary energy source in people's production and daily life, bringing endless convenience. Therefore, ensuring a stable and reliable supply of electricity has become one of the most important tasks of the power system.

[0003] Currently, an increasing number of new energy power generation systems are being integrated into the power grid and generating electricity; a high proportion of new energy integration has become the norm for provincial power grids. However, during periods of high new energy generation and light grid load, the provincial main power grid frequently experiences persistently high voltage, which not only reduces power quality but also seriously threatens the safe and stable operation of the power grid and power equipment.

[0004] Currently, most solutions for determining the causes of high voltage in provincial power grids focus on transient voltage risk analysis, rather than conducting comprehensive and systematic research on the root causes of high voltage in provincial power grids. Therefore, the reliability and accuracy of existing solutions are relatively poor. Summary of the Invention

[0005] One of the objectives of this invention is to provide a highly reliable and accurate method for determining the cause of high voltage in provincial power grids with a high proportion of new energy sources.

[0006] The second objective of this invention is to provide a system for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources.

[0007] The method for determining the cause of high voltage in a provincial power grid with a high proportion of renewable energy provided by this invention includes the following steps:

[0008] S1. Obtain data information on provincial power grids with a high proportion of new energy sources;

[0009] S2. Based on the data information obtained in step S1, determine the abnormality of transformer tap setting, the abnormality of reactive power compensation link, the abnormality of reactive power backfeed from the lower power grid, the abnormality of unit phase-advancing capacity utilization, and the abnormality of capacitive reactive power surplus influence.

[0010] S3. Based on the judgment results obtained in step S2, a comprehensive assessment is conducted to determine the cause of the high voltage in the provincial power grid with a high proportion of new energy sources.

[0011] Step S1, which involves obtaining data information on the target high-proportion provincial power grid with renewable energy, specifically includes the following steps:

[0012] Acquire data information on provincial power grids with a high proportion of renewable energy.

[0013] The data information includes the theoretical and measured voltages on each side of the transformer, the transformer tap ratio correction coefficient, the rated capacity of the reactor, the actual inductive output value of the reactor, the reactive power flow direction and reactive power transmission amount between each voltage level, and the leading phase operating time and leading phase depth of each unit during operation.

[0014] Step S2, which involves determining abnormalities in transformer tap settings, reactive power compensation, downstream reactive power backfeeding, generator phase-advancing capacity utilization, and capacitive reactive power surplus based on the data obtained in step S1, specifically includes the following steps:

[0015] Analyze the operating status and voltage deviation of the transformer taps to determine abnormal transformer tap settings;

[0016] The inductive reactive power compensation degree and actual output characteristics are calculated to determine the abnormality of the reactive power compensation link.

[0017] Monitor the power flow and reactive power direction of power grids at all levels, and determine the abnormality of reactive power backfeed to lower-level power grids;

[0018] Statistical analysis of the reactive power operation status of various generator sets, and determination of abnormal utilization of the unit's leading phase capacity;

[0019] Based on line parameters and operating voltage, calculate the real-time total charging power of the target high-proportion renewable energy provincial power grid, and determine the abnormal impact of capacitive reactive power surplus.

[0020] The determination of abnormal transformer tap settings specifically includes the following steps:

[0021] The theoretical voltage and voltage deviation on each side of the transformer are calculated using the following formula:

[0022] In the formula The calculated theoretical voltage value on the medium-voltage side of the transformer; This represents the real-time bus voltage value on the high-voltage side of the transformer. This refers to the rated voltage on the medium-voltage side of the transformer. This refers to the rated voltage on the high-voltage side of the transformer. This is the transformer tap ratio correction factor, when the transformer is a 500kV transformer. When the transformer is a 220kV transformer , This is the difference between the actual tap position and the reference tap position of the transformer. The calculated theoretical voltage value on the low-voltage side of the transformer; This refers to the rated voltage on the low-voltage side of the transformer. This represents the voltage difference on the medium-voltage side of the transformer. These are measured values ​​on the medium-voltage side of the transformer. This represents the voltage difference on the low-voltage side of the transformer. These are measured values ​​on the low-voltage side of the transformer.

[0023] If both transformer rule 1 and transformer rule 2 are met, the transformer tap setting is determined to be abnormal; otherwise, the transformer tap setting is determined to be normal.

[0024] Transformer Rule 1: The actual operating tap position of the transformer is not within the set reasonable tap position range;

[0025] Transformer Rule 2: If the target power system is a 500kV power system and If the target power system is a 220kV power system and or .

[0026] The determination of anomalies in the reactive power compensation process specifically includes the following steps:

[0027] The regional inductive reactive power compensation degree and reactor output attenuation rate are calculated using the following formulas:

[0028] In the formula For regional inductive reactive power compensation; This refers to the rated capacity of the reactor; The reactive power of the regional lines at rated voltage; The reactor output attenuation rate; For the actual inductive output of the reactor;

[0029] The following rules are used to determine anomalies in the reactive power compensation process:

[0030] When the regional inductive reactive power compensation degree If the power output is below the set threshold and the reactor output attenuation rate is greater than the set threshold, the reactive power compensation circuit is deemed abnormal.

[0031] The determination of reactive power backfeed anomalies in the lower-level power grid specifically includes the following steps:

[0032] When the provincial power grid with a high proportion of new energy is in operation, the reactive power flow direction and reactive power transmission volume between the 500kV, 220kV and 110kV power grid systems in the region are statistically analyzed respectively.

[0033] If the reactive power transmitted from the 220kV power grid to the 500kV power grid is greater than the total charging power of the lines under rated voltage, the reactive power transmitted from the lower-level distribution network to the upper-level main grid is greater than the total charging power of the lines under rated voltage, and the duration of the reactive power backfeed from the lower-level distribution network to the upper-level main grid exceeds a set value, then the reactive power backfeed of the lower-level power grid is determined to be abnormal.

[0034] The determination of abnormal utilization of the unit's phase advance capability specifically includes the following steps:

[0035] Statistics on reactive power output, phase advance time, and phase advance depth of conventional thermal power units, hydropower units, and new energy power plants;

[0036] The following formula is used to calculate the capacity utilization rate of conventional thermal power units and hydropower units:

[0037] In the formula For the utilization rate of the unit's phase advance capability; This represents the reactive power currently absorbed by the unit. The maximum phase absorption capacity designed for the unit;

[0038] The following rules are used to determine abnormalities in the utilization of the unit's advance phase capacity:

[0039] like If the value is less than the set threshold, the unit's phase advance capability is deemed to be abnormally utilized.

[0040] If a unit fails to absorb reactive power and the duration of reactive power generation exceeds the set threshold during the operation of a provincial power grid with a high proportion of new energy sources and the operating voltage is higher than the set threshold, then the unit's reactive power generation capacity utilization is deemed abnormal.

[0041] The determination of the abnormal impact of capacitive reactive power surplus includes the following steps:

[0042] The total real-time charging power of the entire network is calculated using the following formula:

[0043] In the formula This represents the actual charging coefficient per unit length of line i under the current operating voltage; The reference charging coefficient for line i under rated voltage; Let be the operating bus voltage of line i; The rated voltage of line i; The total charging power of the entire network in real time; Let i be the length of line i;

[0044] During the light-load operation period set by the provincial power grid with a target high proportion of new energy, if If the value exceeds the set threshold, the capacitive reactive power surplus is deemed to have an abnormal impact.

[0045] Step S3, which involves comprehensively considering the judgment results obtained in step S2 to determine the cause of high voltage in the provincial power grid with a high proportion of new energy, specifically includes the following steps:

[0046] The weight for abnormal transformer tap settings is set to The weight of abnormalities in the reactive power compensation process is: The weight of reactive power backfeed anomalies in the lower-level power grid is: The weight of the abnormality in the unit's phase advance capability is: The weight of the abnormal impact of capacitive reactive power surplus is ;

[0047] If the transformer tap setting is determined to be abnormal, then the transformer tap setting factor should be identified. The value is ,otherwise ;

[0048] If the reactive power compensation process is determined to be abnormal, then the factors related to the reactive power compensation process are... The value is ,otherwise ;

[0049] If the problem is determined to be an abnormality in reactive power backfeed from the lower-level power grid, then the factors contributing to the reactive power backfeed from the lower-level power grid are as follows. The value is ,otherwise ;

[0050] If the unit's advance capability utilization is determined to be abnormal, then the factors related to the unit's advance capability utilization will be considered. The value is ,otherwise ;

[0051] If the abnormality is determined to be due to the impact of capacitive reactive power surplus, then the factors affecting capacitive reactive power surplus will be... The value is ,otherwise ; The base score is set;

[0052] The overall risk score is calculated. for ;

[0053] The following rules are used to determine the cause of high voltage in provincial power grids with a high proportion of renewable energy:

[0054] If the overall risk score If the voltage is less than or equal to the set threshold, it is determined that the voltage of the target high-proportion new energy provincial power grid is not too high;

[0055] If the overall risk score If the voltage exceeds the set threshold, the voltage of the target high-proportion renewable energy provincial power grid is determined to be too high; at this time, the values ​​of each factor are output. The value and corresponding reason, and determine the factor value. The higher the voltage, the greater its contribution to the high voltage of provincial power grids with a high proportion of new energy.

[0056] This invention also provides a system for determining the cause of high voltage in a high-proportion renewable energy provincial power grid, comprising a data acquisition module, a factor determination module, and a comprehensive determination module; the data acquisition module, factor determination module, and comprehensive determination module are connected in series; the data acquisition module is used to acquire data information of the target high-proportion renewable energy provincial power grid and upload the data information to the factor determination module; the factor determination module is used to determine, based on the received data information and the acquired data information, abnormalities in transformer tap setting, abnormalities in reactive power compensation, abnormalities in reactive power backfeeding from the lower-level power grid, abnormalities in the utilization of unit phase-advancing capacity, and abnormalities in the impact of capacitive reactive power surplus, and upload the data information to the comprehensive determination module; the comprehensive determination module is used to comprehensively consider, based on the received data information and the obtained determination results, to complete the determination of the cause of high voltage in the target high-proportion renewable energy provincial power grid.

[0057] The method and system for determining the cause of high voltage in a provincial power grid with a high proportion of renewable energy provided by this invention acquires and processes data information of the target provincial power grid with a high proportion of renewable energy, and comprehensively considers five aspects: transformer tap setting, reactive power compensation link, reactive power backfeed from the downstream power grid, utilization of the unit's leading phase capacity, and the impact of capacitive reactive power surplus. This not only achieves the determination of the cause of high voltage in a provincial power grid with a high proportion of renewable energy, but also has higher reliability and better accuracy. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the method flow of the present invention.

[0059] Figure 2 This is a schematic diagram of the functional modules of the system of the present invention. Detailed Implementation

[0060] like Figure 1The diagram shown is a flowchart of the method of the present invention: The method for determining the cause of high voltage in a provincial power grid with a high proportion of new energy disclosed in this invention includes the following steps:

[0061] S1. Obtain data information on the target provincial power grid with a high proportion of renewable energy; specifically including the following steps:

[0062] Acquire data information on provincial power grids with a high proportion of renewable energy.

[0063] The data information includes the theoretical and measured voltages on each side of the transformer, the transformer tap ratio correction coefficient, the rated capacity of the reactor, the actual inductive output value of the reactor, the reactive power flow direction and reactive power transmission amount between each voltage level, and the leading phase operating time and leading phase depth of each unit during operation.

[0064] S2. Based on the data obtained in step S1, determine the following abnormalities: transformer tap setting abnormalities, reactive power compensation abnormalities, downstream power grid reactive power backfeed abnormalities, unit phase-advancing capacity utilization abnormalities, and capacitive reactive power surplus impact abnormalities. Specifically, this includes the following steps:

[0065] Analyze the transformer tap position operation status and voltage deviation values ​​to determine abnormal transformer tap position settings; specifically, this includes the following steps:

[0066] The theoretical voltage and voltage deviation on each side of the transformer are calculated using the following formula:

[0067] In the formula The calculated theoretical voltage value on the medium-voltage side of the transformer; This represents the real-time bus voltage value on the high-voltage side of the transformer. This refers to the rated voltage on the medium-voltage side of the transformer. This refers to the rated voltage on the high-voltage side of the transformer. This is the transformer tap ratio correction factor, when the transformer is a 500kV transformer. When the transformer is a 220kV transformer , This is the difference between the actual tap position and the reference tap position of the transformer. The calculated theoretical voltage value on the low-voltage side of the transformer; This refers to the rated voltage on the low-voltage side of the transformer. This represents the voltage difference on the medium-voltage side of the transformer. These are measured values ​​on the medium-voltage side of the transformer. This represents the voltage difference on the low-voltage side of the transformer. These are measured values ​​on the low-voltage side of the transformer.

[0068] If both transformer rule 1 and transformer rule 2 are met, the transformer tap setting is determined to be abnormal; otherwise, the transformer tap setting is determined to be normal.

[0069] Transformer Rule 1: The actual operating tap position of the transformer is not within the set reasonable tap position range;

[0070] Transformer Rule 2: If the target power system is a 500kV power system and If the target power system is a 220kV power system and or ;

[0071] The inductive reactive power compensation degree and actual output characteristics are calculated to determine any anomalies in the reactive power compensation process; specifically, the following steps are included:

[0072] The regional inductive reactive power compensation degree and reactor output attenuation rate are calculated using the following formulas:

[0073] In the formula For regional inductive reactive power compensation; This refers to the rated capacity of the reactor; The reactive power of the regional lines at rated voltage; The reactor output attenuation rate; For the actual inductive output of the reactor;

[0074] The following rules are used to determine anomalies in the reactive power compensation process:

[0075] When the regional inductive reactive power compensation degree If the reactive power compensation circuit is abnormal, the output attenuation rate of the reactor is greater than the set threshold (120% for urban / small hydropower rich areas and 115% for ordinary areas) and the output attenuation rate of the reactor is greater than the set threshold (preferably 5%).

[0076] Monitor the power flow and reactive power direction of power grids at all levels, and determine any abnormalities in reactive power backfeeding to lower-level power grids; specifically, this includes the following steps:

[0077] When the provincial power grid with a high proportion of new energy is in operation, the reactive power flow direction and reactive power transmission volume between the 500kV, 220kV and 110kV power grid systems in the region are statistically analyzed respectively.

[0078] If the reactive power transmission from the 220kV power grid system to the 500kV power grid system is greater than the total charging power of the lines under rated voltage, the reactive power transmission from the lower-level distribution network to the upper-level main grid is greater than the total charging power of the lines under rated voltage, and the duration of the reactive power back-transmission from the lower-level distribution network to the upper-level main grid exceeds a set value (preferably 1 hour), then the reactive power back-transmission of the lower-level power grid is determined to be abnormal.

[0079] The reactive power operation status of various generator units (including conventional thermal power units, hydropower units, and new energy power plants) is statistically analyzed to determine abnormalities in the utilization of the unit's leading-phase capacity; specifically, the following steps are included:

[0080] Statistics on reactive power output, phase advance time, and phase advance depth of conventional thermal power units, hydropower units, and new energy power plants;

[0081] The following formula is used to calculate the capacity utilization rate of conventional thermal power units and hydropower units:

[0082] In the formula For the utilization rate of the unit's phase advance capability; This represents the reactive power currently absorbed by the unit. The maximum phase absorption capacity designed for the unit;

[0083] The following rules are used to determine abnormalities in the utilization of the unit's advance phase capacity:

[0084] like If the value is less than the set threshold (preferably 15%), the unit's phase advance capability utilization is determined to be abnormal.

[0085] If, during the operation of a provincial power grid with a high proportion of new energy and the operating voltage is higher than the set threshold, the unit (especially small hydropower units without regulation capacity and new energy power stations) fails to absorb reactive power and the duration of reactive power generation exceeds the set threshold, the unit's reactive power utilization is deemed abnormal.

[0086] Based on line parameters and operating voltage, calculate the real-time total charging power of the target high-proportion renewable energy provincial power grid, and determine the anomalies caused by capacitive reactive power surplus; specifically, the following steps are included:

[0087] The total real-time charging power of the entire network is calculated using the following formula:

[0088] In the formula This represents the actual charging coefficient per unit length of line i under the current operating voltage; The reference charging coefficient for line i under rated voltage; Let be the operating bus voltage of line i; The rated voltage of line i; The total charging power of the entire network in real time; Let i be the length of line i;

[0089] During the light-load operation period set by the provincial power grid with a target high proportion of new energy, if If the value exceeds the set threshold (preferably 1.05 times the design charging power), the capacitive reactive power surplus is deemed to have an abnormal impact.

[0090] S3. Based on the judgment results obtained in step S2, a comprehensive assessment is conducted to determine the cause of high voltage in the provincial power grid with a high proportion of new energy sources; specifically, the following steps are included:

[0091] The weight for abnormal transformer tap settings is set to (The preferred value is 0.20), and the weight of abnormalities in the reactive power compensation process is... (The preferred value is 0.35), and the weight of reactive power backfeed anomalies in the lower-level power grid is... (The preferred value is 0.25), and the weight of abnormal utilization of the unit's phase advance capability is... (The preferred value is 0.15) and the weight of the abnormal impact of capacitive reactive power surplus is: (The preferred value is 0.05);

[0092] If the transformer tap setting is determined to be abnormal, then the transformer tap setting factor should be identified. The value is ,otherwise ;

[0093] If the reactive power compensation process is determined to be abnormal, then the factors related to the reactive power compensation process are... The value is ,otherwise ;

[0094] If the problem is determined to be an abnormality in reactive power backfeed from the lower-level power grid, then the factors contributing to the reactive power backfeed from the lower-level power grid are as follows. The value is ,otherwise ;

[0095] If the unit's advance capability utilization is determined to be abnormal, then the factors related to the unit's advance capability utilization will be considered. The value is ,otherwise ;

[0096] If the abnormality is determined to be due to the impact of capacitive reactive power surplus, then the factors affecting capacitive reactive power surplus will be... The value is ,otherwise ; The base score is set;

[0097] The overall risk score is calculated. for ;

[0098] The following rules are used to determine the cause of high voltage in provincial power grids with a high proportion of renewable energy:

[0099] If the overall risk score If the voltage is less than or equal to the set threshold, it is determined that the voltage of the target high-proportion new energy provincial power grid is not too high;

[0100] If the overall risk score If the voltage exceeds the set threshold, the voltage of the target high-proportion renewable energy provincial power grid is determined to be too high; at this time, the values ​​of each factor are output. The value and corresponding reason, and determine the factor value. The higher the voltage, the greater its contribution to the high voltage of provincial power grids with a high proportion of new energy.

[0101] The method of the present invention will be described below with reference to an embodiment:

[0102] First, obtain the data information of the target provincial power grid;

[0103] All 500kV transformers are operating at rated tap 3, which is within a reasonable range. Therefore, the transformer tap position is not the cause of the high voltage. For transformers with a turns ratio of... A standard 220kV transformer has a reasonable tap range of 4 to 8 taps. However, a certain transformer was operating at tap 2, and the calculated voltage value on the 110kV side... Actual measurement , The improper tap setting of the 220kV transformer was determined to be the cause of the high voltage.

[0104] By compiling statistics on the rated voltage and capacity of reactors across the province, and relevant line length parameters, the inductive reactive power compensation at the 500kV level was calculated. The requirements are basically met; the inductive reactive power compensation at the 220kV level... The shortfall is significant; furthermore, based on the theoretical output calculated from the actual operating voltage of the busbar, the 500kV reactor has been operating below its rated voltage for a long time, resulting in an actual output lower than the nameplate value, and the reactor output attenuation rate is high. The insufficient inductive reactive power compensation configuration and the power output reduction of the equipment were determined to be the causes of the high voltage.

[0105] The reactive power flow of the 500kV, 220kV and 110kV power grids was statistically analyzed in layers. The monitoring results showed that during the light load period of the power grid, a large amount of reactive power from the 220kV lower-level power grid was sent upward to the 500kV main grid. The amount of reactive power sent upward far exceeded the normal charging power of the line, and the duration was more than 1 hour. It was determined that the reactive power backflow from the lower-level power grid was the cause of the high voltage.

[0106] Statistical analysis of operational data from various generating units within the province revealed that large thermal and hydropower units operated in a leading-phase mode during periods of high voltage to absorb reactive power from the grid, and the utilization rate of this leading-phase capacity was [not specified]. Small hydropower units lack the ability to advance phase and continuously transmit reactive power. New energy power plants have the ability to advance phase but have not fully utilized it and continuously send reactive power to the grid. It is determined that the ineffective use of the advancing phase capabilities of new energy power plants and small hydropower units and the excessive generation of reactive power are the causes of high voltage.

[0107] The charging power coefficient was adjusted based on the actual operating voltage of the transmission lines to calculate the total charging power of the entire network. The results show that during periods of high voltage, the voltage at the 500kV level reaches 544.8kV, requiring the charging power coefficient to be adjusted from 1.18Mvar / km to 1.22Mvar / km. If the charging power is less than 1.05 times the design charging power, it is determined that the increase in line charging power is not caused by high voltage.

[0108] Finally, by summarizing the results of the above six types of analysis and the basic weights of each dimension, it was determined that the voltage of the provincial power grid with a high proportion of new energy was too high; and the contribution of each influencing factor on the voltage was clarified.

[0109] like Figure 2 The diagram shows the functional modules of the system of the present invention: The system disclosed in this invention for determining the cause of high voltage in a high-proportion renewable energy provincial power grid includes a data acquisition module, a factor determination module, and a comprehensive determination module; the data acquisition module, factor determination module, and comprehensive determination module are connected in series; the data acquisition module is used to acquire data information of the target high-proportion renewable energy provincial power grid and upload the data information to the factor determination module; the factor determination module is used to determine, based on the received data information and the acquired data information, abnormal transformer tap setting, abnormal reactive power compensation, abnormal reactive power backfeed from the lower-level power grid, abnormal utilization of unit phase-advancing capacity, and abnormal impact of capacitive reactive power surplus, and upload the data information to the comprehensive determination module; the comprehensive determination module is used to comprehensively consider, based on the received data information and the obtained determination results, to complete the determination of the cause of high voltage in the target high-proportion renewable energy provincial power grid.

Claims

1. A method for determining the cause of high voltage in a provincial power grid with a high proportion of renewable energy, comprising the following steps: S1. Obtain data information on provincial power grids with a high proportion of new energy sources; S2. Based on the data information obtained in step S1, determine the abnormality of transformer tap setting, the abnormality of reactive power compensation link, the abnormality of reactive power backfeed from the lower power grid, the abnormality of unit phase-advancing capacity utilization, and the abnormality of capacitive reactive power surplus influence. S3. Based on the judgment results obtained in step S2, a comprehensive assessment is conducted to determine the cause of the high voltage in the provincial power grid with a high proportion of new energy sources.

2. The method for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources according to claim 1, characterized in that... Step S1, which involves obtaining data information on the target high-proportion provincial power grid with renewable energy, specifically includes the following steps: Acquire data information on provincial power grids with a high proportion of renewable energy. The data information includes the theoretical and measured voltages on each side of the transformer, the transformer tap ratio correction coefficient, the rated capacity of the reactor, the actual inductive output value of the reactor, the reactive power flow direction and reactive power transmission amount between each voltage level, and the leading phase operating time and leading phase depth of each unit during operation.

3. The method for determining the cause of high voltage in provincial power grids with a high proportion of new energy sources according to claim 2, characterized in that... Step S2, which involves determining abnormalities in transformer tap settings, reactive power compensation, downstream reactive power backfeeding, generator phase-advancing capacity utilization, and capacitive reactive power surplus based on the data obtained in step S1, specifically includes the following steps: Analyze the operating status and voltage deviation of the transformer taps to determine abnormal transformer tap settings; The inductive reactive power compensation degree and actual output characteristics are calculated to determine the abnormality of the reactive power compensation link. Monitor the power flow and reactive power direction of power grids at all levels, and determine the abnormality of reactive power backfeed to lower-level power grids; Statistical analysis of the reactive power operation status of various generator sets, and determination of abnormal utilization of the unit's leading phase capacity; Based on line parameters and operating voltage, calculate the real-time total charging power of the target high-proportion renewable energy provincial power grid, and determine the abnormal impact of capacitive reactive power surplus.

4. The method for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources according to claim 3, characterized in that... The determination of abnormal transformer tap settings specifically includes the following steps: The theoretical voltage and voltage deviation on each side of the transformer are calculated using the following formula: In the formula The calculated theoretical voltage value on the medium-voltage side of the transformer; This represents the real-time bus voltage value on the high-voltage side of the transformer. This refers to the rated voltage on the medium-voltage side of the transformer. This refers to the rated voltage on the high-voltage side of the transformer. This is the transformer tap ratio correction factor, when the transformer is a 500kV transformer. When the transformer is a 220kV transformer , This is the difference between the actual tap position and the reference tap position of the transformer. The calculated theoretical voltage value on the low-voltage side of the transformer; This refers to the rated voltage on the low-voltage side of the transformer. This represents the voltage difference on the medium-voltage side of the transformer. These are measured values ​​on the medium-voltage side of the transformer. This represents the voltage difference on the low-voltage side of the transformer. These are measured values ​​on the low-voltage side of the transformer. If both transformer rule 1 and transformer rule 2 are met, the transformer tap setting is determined to be abnormal; otherwise, the transformer tap setting is determined to be normal. Transformer Rule 1: The actual operating tap position of the transformer is not within the set reasonable tap position range; Transformer Rule 2: If the target power system is a 500kV power system and If the target power system is a 220kV power system and or .

5. The method for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources according to claim 4, characterized in that... The determination of anomalies in the reactive power compensation process specifically includes the following steps: The regional inductive reactive power compensation degree and reactor output attenuation rate are calculated using the following formulas: In the formula For regional inductive reactive power compensation; This refers to the rated capacity of the reactor; The reactive power of the regional lines at rated voltage; The reactor output attenuation rate; For the actual inductive output of the reactor; The following rules are used to determine anomalies in the reactive power compensation process: When the regional inductive reactive power compensation degree If the power output is below the set threshold and the reactor output attenuation rate is greater than the set threshold, the reactive power compensation circuit is deemed abnormal.

6. The method for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources as described in claim 5, characterized in that... The determination of reactive power backfeed anomalies in the lower-level power grid specifically includes the following steps: When the provincial power grid with a high proportion of new energy is in operation, the reactive power flow direction and reactive power transmission volume between the 500kV, 220kV and 110kV power grid systems in the region are statistically analyzed respectively. If the reactive power transmitted from the 220kV power grid to the 500kV power grid is greater than the total charging power of the lines under rated voltage, the reactive power transmitted from the lower-level distribution network to the upper-level main grid is greater than the total charging power of the lines under rated voltage, and the duration of the reactive power backfeed from the lower-level distribution network to the upper-level main grid exceeds a set value, then the reactive power backfeed of the lower-level power grid is determined to be abnormal.

7. The method for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources as described in claim 6, characterized in that... The determination of abnormal utilization of the unit's phase advance capability specifically includes the following steps: Statistics on reactive power output, phase advance time, and phase advance depth of conventional thermal power units, hydropower units, and new energy power plants; The following formula is used to calculate the capacity utilization rate of conventional thermal power units and hydropower units: In the formula For the utilization rate of the unit's phase advance capability; This represents the reactive power currently absorbed by the unit. The maximum phase absorption capacity designed for the unit; The following rules are used to determine abnormalities in the utilization of the unit's advance phase capacity: like If the value is less than the set threshold, the unit's phase advance capability is deemed to be abnormally utilized. If a unit fails to absorb reactive power and the duration of reactive power generation exceeds the set threshold during the operation of a provincial power grid with a high proportion of new energy sources and the operating voltage is higher than the set threshold, then the unit's reactive power generation capacity utilization is deemed abnormal.

8. The method for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources according to claim 7, characterized in that... The determination of the abnormal impact of capacitive reactive power surplus includes the following steps: The total real-time charging power of the entire network is calculated using the following formula: In the formula This represents the actual charging coefficient per unit length of line i under the current operating voltage; The reference charging coefficient for line i under rated voltage; Let be the operating bus voltage of line i; The rated voltage of line i; The total charging power of the entire network in real time; Let i be the length of line i; During the light-load operation period set by the provincial power grid with a target high proportion of new energy, if If the value exceeds the set threshold, the capacitive reactive power surplus is deemed to have an abnormal impact.

9. The method for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources as described in claim 8, characterized in that... Step S3, which involves comprehensively considering the judgment results obtained in step S2 to determine the cause of high voltage in the provincial power grid with a high proportion of new energy, specifically includes the following steps: The weight for abnormal transformer tap settings is set to The weight of abnormalities in the reactive power compensation process is: The weight of reactive power backfeed anomalies in the lower-level power grid is: The weight of the abnormality in the unit's phase advance capability is: The weight of the abnormal impact of capacitive reactive power surplus is ; If the transformer tap setting is determined to be abnormal, then the transformer tap setting factor should be identified. The value is ,otherwise ; If the reactive power compensation process is determined to be abnormal, then the factors related to the reactive power compensation process are... The value is ,otherwise ; If the problem is determined to be an abnormality in reactive power backfeed from the lower-level power grid, then the factors contributing to the reactive power backfeed from the lower-level power grid are as follows. The value is ,otherwise ; If the unit's advance capability utilization is determined to be abnormal, then the factors related to the unit's advance capability utilization will be considered. The value is ,otherwise ; If the abnormality is determined to be due to the impact of capacitive reactive power surplus, then the factors affecting capacitive reactive power surplus will be... The value is ,otherwise ; The base score is set; The overall risk score is calculated. for ; The following rules are used to determine the cause of high voltage in provincial power grids with a high proportion of renewable energy: If the overall risk score If the voltage is less than or equal to the set threshold, it is determined that the voltage of the target high-proportion new energy provincial power grid is not too high; If the overall risk score If the voltage exceeds the set threshold, the voltage of the target high-proportion renewable energy provincial power grid is determined to be too high; at this time, the values ​​of each factor are output. The value and corresponding reason, and determine the factor value. The higher the voltage, the greater its contribution to the high voltage of provincial power grids with a high proportion of new energy.

10. A system for implementing the method for determining the cause of high voltage in a provincial power grid with a high proportion of new energy sources as described in any one of claims 1 to 9, characterized in that... It includes a data acquisition module, a factor determination module, and a comprehensive determination module; the data acquisition module, factor determination module, and comprehensive determination module are connected in series; the data acquisition module is used to acquire data information of the target high-proportion new energy provincial power grid and upload the data information to the factor determination module; The factor determination module is used to determine abnormalities in transformer tap setting, reactive power compensation, reactive power backfeed from the downstream power grid, utilization of unit phase-advancing capacity, and impact of capacitive reactive power surplus based on the received and acquired data information, and uploads the data information to the comprehensive determination module. The comprehensive judgment module is used to comprehensively consider the received data information and the judgment results to determine the cause of high voltage in the provincial power grid with a high proportion of new energy.

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