A new energy power station grid-connected adaptability analysis method and system thereof

Abstract

The application discloses a kind of main station substation coordination's new energy power station grid-connected adaptability analysis method and system, the method of the application includes the following steps: step S1 dispatch main station is calculated task distribution by edge gateway;Step S2 each new energy substation executes computing task asynchronously according to working condition;Step S3 edge gateway collects each substation computing terminal result and section information compression encryption and returns;Step S4 dispatch main station aggregates multiple substation return result and executes grid-connected adaptability analysis.The application extends the current centralized computing mode, by introducing edge computing related technology, fully utilizes the computing resources of new energy power station end, improves the degree of multi-source data fusion.The method of the application combines network computing, data storage and advanced application, can effectively reduce various losses caused by data transmission, has certain engineering application value.

Description

Technical Field

[0001] This invention belongs to the field of new energy grid connection analysis and calculation. This invention relates to a method and system for analyzing the grid connection adaptability of new energy power plants. Background Technology

[0002] Grid-connection adaptability analysis of renewable energy power plants is a crucial means of understanding their grid-connected operational characteristics. As the proportion of renewable energy installed capacity in the power grid continues to rise, the amount of data requiring grid-connection adaptability analysis is increasing. In recent years, the requirements for grid connection standards related to large-scale renewable energy grid integration have been continuously strengthened, placing higher computational demands on various detailed renewable energy grid-connection performance indicators, further increasing the pressure on data processing. Existing grid-connection adaptability analysis systems are mainly deployed at the dispatch master station, collecting data from various renewable energy power plants and performing centralized analysis at the master station. This model, as the number of renewable energy power plants connected to the grid continues to increase, is increasingly limited by transmission channels and speed, and can no longer meet the requirements of large-scale analysis and computation. Furthermore, when using the master station centralized processing mode, due to centralized data storage, the requirement for data redundancy is high. With the increase in renewable energy power plants, the computational resources required for evaluation and analysis increase dramatically, and the data sources acquired by the master station are limited, all of which affect the real-time performance and depth of the grid-connection adaptability analysis results for renewable energy power plants. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method and system for grid-connected adaptability analysis of new energy power plants. By introducing edge computing technologies, it fully utilizes the computing resources at the power plant site to improve the degree of multi-source data fusion. Based on this, a practical master-sub-station collaborative computing model is formed, thereby improving the real-time performance, security, and economy of grid-connected adaptability analysis of new energy power plants.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0005] The present invention provides a method for analyzing the grid-connected adaptability of new energy power plants, the method comprising:

[0006] The scheduling master station distributes computing tasks through the edge gateway;

[0007] Each new energy substation executes the computing task asynchronously according to its operating conditions after receiving the computing task;

[0008] After the calculation task is completed, each new energy substation compresses and encrypts the calculation results and cross-section information through the edge gateway and sends them back to the dispatch master station. The dispatch master station performs grid-connection adaptability analysis based on the returned results.

[0009] A further improvement of the present invention is that the computing task includes a periodic timed task and a randomized triggered task.

[0010] A further improvement of this invention is that: after receiving a computing task, each new energy substation asynchronously executes the computing task according to its operating conditions, and the specific operation is as follows:

[0011] Step a1: Collect the three-phase voltage and three-phase current analog signals of the voltage transformer and current transformer at the grid connection point of the new energy power station. Through analog-to-digital conversion and digital signal processing technology, extract the grid frequency f, the fundamental positive / negative / zero sequence components of the three-phase voltage, the fundamental positive / negative / zero sequence components of the three-phase current, the active power and reactive power of the fundamental positive sequence component, and the active current and reactive current of the fundamental positive sequence component.

[0012] Step a2: Based on the grid frequency, fundamental positive / negative / zero sequence components of the three-phase voltage, fundamental positive / negative / zero sequence components of the three-phase current, fundamental positive sequence active power, reactive power, and active and reactive current of the fundamental positive sequence component extracted in Step 1, calculate various indicators of grid-connected adaptability of new energy power plants, including tolerance-type adaptability indicators and active support-type adaptability indicators.

[0013] A further improvement of this invention regarding the grid connection point of a new energy power plant is as follows: In step a1, the specific steps for extracting the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase voltage, the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase current, the active power and reactive power of the fundamental positive-sequence component, and the active current and reactive current of the fundamental positive-sequence component are as follows:

[0014] Step a11: Extract the fundamental component using Fourier transform. The extraction process is as follows:

[0015] (1)

[0016] Where: t is time. This represents the instantaneous value of phase A voltage. and Phase A voltage The real and imaginary parts of a complex phasor Where is the power frequency, and T is the cycle time window corresponding to the power frequency;

[0017] Similarly, we can obtain , , , , , , , , , Furthermore, the three-phase voltage and three-phase current phasors are synthesized using the following formulas:

[0018] (2)

[0019] Where j is the imaginary unit of the complex phasor, and its value is... ; , These are the complex phasors of the voltages in phases B and C; and Phase B voltage The real and imaginary parts of a complex phasor; and C-phase voltage The real and imaginary parts of a complex phasor; , , These are the complex phasors of the three-phase currents A, B, and C; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor;

[0020] Step a12: Extract the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase voltage and three-phase current through positive-negative-sequence transformation. The expressions are as follows:

[0021] (3)

[0022] Where: a is a basic element of the transformation matrix, and its value , j is the imaginary unit of the complex number, and its value is... ;

[0023] , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase voltage.

[0024] , , These are the three-phase voltage phasors of A, B, and C.

[0025] , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase current.

[0026] , , These are the phasors of the three-phase currents A, B, and C;

[0027] Step a13: Calculate the active and reactive power of the fundamental positive sequence component, as shown in the following expressions:

[0028] (4)

[0029] Where: the subscript "1" represents the fundamental frequency, and the subscript "+" represents positive sequence. and The fundamental positive sequence component of the three-phase voltage The real and imaginary parts, and The fundamental positive sequence component of the three-phase current The real and imaginary parts, P 1+ Q represents the active power of the fundamental positive sequence component. 1+ This represents the reactive power of the fundamental positive sequence component.

[0030] Step a14: Calculate the active and reactive currents of the fundamental positive sequence component, as shown in the following expressions:

[0031] (5)

[0032] in: This represents the active current of the fundamental positive sequence component. This represents the reactive current of the fundamental positive sequence component. It represents the complex modulus of the fundamental positive sequence component of the three-phase voltage.

[0033] A further improvement of the present invention is that: the tolerance-type adaptability index in step a2 includes the voltage tolerance-type adaptability sub-index E. tol_v and frequency tolerance adaptive sub-index E tol_f The specific analysis process is as follows:

[0034] Step a21, targeting the voltage tolerance type adaptability sub-index E tol_v The following five working conditions are determined in sequence:

[0035] Judgment Condition 1: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is between [90% and 110%] of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station are operating normally, then it has voltage deviation tolerance adaptability. At this time, the voltage tolerance adaptability sub-index is E. tol_v_1 E tol_v_1 A value of 1 indicates that the device does not possess voltage deviation tolerance adaptability. tol_v_1 The value is 0;

[0036] Judgment Condition 2: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is as low as 20% of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station can operate continuously for more than 625ms, then it has low voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_2 E tol_v_2 A value of 1 indicates low voltage tolerance capability; otherwise, it lacks this capability. tol_v_2 The value is 0;

[0037] Judgment Condition 3: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [125% and 130%] of the nominal voltage; Corresponding criterion: If all power generation units in the new energy power station can guarantee continuous operation without disconnecting from the grid for 500ms, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_3 E tol_v_3 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_3 The value is 0;

[0038] Judgment Condition 4: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [120%, 125%) of the nominal voltage; Corresponding criterion: If all power generation units in the new energy power station can maintain continuous operation without disconnecting from the grid for 1 second, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_4 E tol_v_4 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_4 The value is 0;

[0039] Condition 5: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [110%, 120%) of the nominal voltage; Corresponding criterion: If all generating units in the new energy power station can maintain continuous operation without disconnecting from the grid for 10 seconds, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_5 E tol_v_5 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_5 The value is 0;

[0040] If any of the above operating conditions fail to meet the corresponding criteria, the new energy power station is deemed to lack voltage withstand adaptability; the voltage withstand adaptability sub-index E is calculated according to formula (6). tol_v value:

[0041] (6)

[0042] In the formula, To analyze the voltage tolerance type adaptability sub-index E tol_v Operating condition number, To analyze the voltage tolerance type adaptability sub-index E tol_v The number of working conditions;

[0043] Step a22, targeting the frequency tolerance adaptive sub-index E tol_f The following four working conditions are determined sequentially:

[0044] Judgment Condition 1: The grid frequency f at the grid connection point of the new energy power station is located in [48.5Hz, 50.5Hz]; Corresponding criterion: If all power generation units in the new energy power station operate continuously, it has frequency deviation tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_1 E tol_f_1 A value of 1 indicates that frequency deviation tolerance is not present. tol_f_1 The value is 0;

[0045] Judgment Condition 2: The grid frequency f at the grid connection point of the new energy power station is located in [48Hz, 48.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 minutes each time the frequency is lower than 48.5Hz, then it has low-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_2 E tol_f_2 A value of 1 indicates low-frequency tolerance; otherwise, it lacks adaptability. tol_f_2 The value is 0;

[0046] Judgment Condition 3: The grid frequency f at the grid connection point of the new energy power station is located in (50.5Hz, 51Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 3 minutes, then it has high-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_3 E tol_f_3 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_3 The value is 0;

[0047] Judgment Condition 4: The grid frequency f at the grid connection point of the new energy power station is located in (51Hz, 51.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 seconds each time the frequency is higher than 50.5Hz, then it has high frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_4 E tol_f_4 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_4 The value is 0;

[0048] If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed to lack frequency tolerance adaptability. The frequency tolerance adaptability sub-index E is then calculated according to formula (7). tol_f value;

[0049] (7)

[0050] In the formula, To analyze the frequency tolerance adaptive sub-index E tol_f Operating condition number, Analysis of frequency tolerance-type adaptive sub-indices E tol_f The number of working conditions.

[0051] A further improvement of the present invention is that: the active support type adaptive index E in a2 tol Including the dynamic active power support sub-indicator E act_p and transient reactive power active support type sub-indicator E act_q The specific calculation process is as follows:

[0052] Step a23, analyze the dynamic active power support sub-index E act_p ;

[0053] The deviation between the actual droop rate and the actual droop rate for the fast frequency response of new energy sources is:

[0054] (8)

[0055] In the formula, k δ% δ% represents the actual droop rate deviation of the new energy fast frequency response, where δ% is the actual droop rate of the new energy fast frequency response. std % represents the droop rate specified for the rapid frequency response of new energy sources, f d The fast frequency response dead zone, measured in Hz, f N The system's rated frequency is in Hz, f is the grid frequency at the new energy power station's grid connection point, and P is the frequency in Hz. N The rated power of the new energy power plant is expressed in MW or P. 1+ 0 The initial value of the active power of the fundamental positive sequence component is given in MW and P. 1+ This represents the active power of the fundamental positive sequence component, expressed in MW.

[0056] Based on the actual droop rate deviation of the fast frequency response of the new energy source, the following two operating conditions are analyzed:

[0057] Judgment Condition 1: The grid frequency f at the grid connection point of the new energy power station is higher than 50.3Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; Corresponding criterion: The active power of the new energy power station can be calculated according to k δ% The active power reduction should not exceed ±5%, at which point the dynamic active power active support sub-index is E. act_p_1 E act_p_1 The value is 1, otherwise E act_p_1 The value is 0;

[0058] Judgment Condition 2: The grid frequency f at the grid connection point of the new energy power station is lower than 49.97Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; corresponding criterion: the active power of the new energy power station is determined according to k δ% The active power is increased by no more than ±5%, at which point the dynamic active power active support sub-index is E. act_p_2 E act_p_2 The value is 1, otherwise E act_p_2 The value is 0;

[0059] If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed to lack dynamic active power support adaptability; the dynamic active power support type sub-index E is calculated according to formula (9). act_p value:

[0060] (9)

[0061] In the formula, To analyze the dynamic active power support sub-index E act_p Operating condition number, To analyze the dynamic active power support sub-index E act_p The number of working conditions;

[0062] Step a24, analyze the transient reactive power active support type sub-index E act_q ;

[0063] The actual deviation of the reactive power support coefficient for new energy sources is calculated as follows:

[0064] (10)

[0065] In the formula, k λ λ represents the actual deviation of the reactive power support coefficient for new energy sources, where λ is the actual reactive power support coefficient. std The recommended value for the reactive power support factor is I. Q1+ I is the reactive current of the fundamental positive sequence component. Q1+ 0 I is the initial value of the reactive current of the fundamental positive sequence component before the fault occurs. N This is the rated value of the fundamental positive sequence reactive current. It represents the complex modulus of the fundamental positive sequence component of the three-phase voltage;

[0066] Based on the actual deviation of the reactive power support coefficient of new energy sources, the following two operating conditions are analyzed:

[0067] Judgment Condition 1: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is [60%, 80%] of the nominal voltage; Corresponding criterion: The actual deviation of the reactive power support coefficient of the new energy power station is 0 ≤ k λ ≤5%, E act_q_1The value is 1, otherwise E act_q_1 The value is 0;

[0068] Judgment Condition 2: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is (110%, 130%) of the nominal voltage; corresponding criterion: the actual deviation of the reactive power support coefficient of the energy power station is 0 ≤ k λ ≤5%, E act_q_2 The value is 1, otherwise E act_q_2 The value is 0;

[0069] If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed not to have the adaptability for transient reactive power active support; the transient reactive power active support type sub-index E is obtained according to formula (11). act_q value;

[0070] (11)

[0071] In the formula, To analyze the transient reactive power active support type sub-index E act_q Operating condition number, To analyze the transient reactive power active support type sub-index E act_q The number of working conditions.

[0072] The present invention provides a grid-connection adaptability analysis system for new energy power plants, comprising a dispatch master station, multiple new energy substations, and an edge gateway, wherein the edge gateway is deployed between the dispatch master station and the new energy substations;

[0073] The scheduling master station distributes computing tasks to multiple new energy substations via the edge gateway, and aggregates the computing results returned by multiple new energy substations to perform grid-connection adaptability analysis.

[0074] The new energy substations execute the assigned computing tasks asynchronously according to the operating conditions;

[0075] The edge gateway distributes the computing tasks assigned by the scheduling master station to each new energy substation, and collects the computing results and cross-sectional information of each new energy substation, compresses and encrypts them, and sends them back to the scheduling master station.

[0076] A further improvement of the present invention is that the new energy substation includes a measurement and control module, a communication module, a high-speed cache module, a storage module, and a computing module;

[0077] The measurement and control module is used to collect the three-phase voltage and three-phase current analog signals of the voltage transformer and current transformer at the grid connection point of the new energy power station. Through analog-to-digital conversion and digital signal processing technology, it extracts the electrical quantity information of the grid connection point of the new energy power station and stores the results in the high-speed cache module. The electrical quantity information of the grid connection point of the new energy power station includes the grid frequency, the fundamental positive sequence / negative sequence / zero sequence components of the three-phase voltage, the fundamental positive sequence / negative sequence / zero sequence components of the three-phase current, the fundamental positive sequence active power, reactive power, and the active current and reactive current of the fundamental positive sequence component.

[0078] The high-speed cache module is used to cache the electrical quantity information of the grid-connected point of the new energy power plant within the calculation cycle output by the measurement and control module. On the one hand, it is used by the calculation module, and on the other hand, it outputs the data to the storage module for long-term storage.

[0079] The calculation module receives electrical quantity information of the grid connection point of the new energy power plant cached in the cache module, and calculates various indicators of the grid connection adaptability of the new energy power plant. These indicators include tolerance-type adaptability indicators and active support-type adaptability indicators. The tolerance-type adaptability indicators include the voltage tolerance-type adaptability sub-indicator E. tol_v and frequency tolerance adaptive sub-index E tol_f Active support-type adaptive indicators include the dynamic active support-type sub-indicator E. act_p and transient reactive power active support type sub-indicator E act_q ;

[0080] The communication module is used for information exchange between the new energy substation and other systems, including monitoring systems, power prediction systems, remote control units (RTUs), and edge gateways.

[0081] A further improvement of this invention at the grid connection point of a new energy power plant is that the measurement and control module performs the following operations:

[0082] Step 1: Extract the fundamental component using Fourier transform. The extraction process is as follows:

[0083] (12)

[0084] Where: t is time. This represents the instantaneous value of phase A voltage. and Phase A voltage The real and imaginary parts of a complex phasor Where is the power frequency, and T is the cycle time window corresponding to the power frequency;

[0085] Similarly, we can obtain , , , , , , , , , Furthermore, the three-phase voltage and three-phase current phasors are synthesized using the following formulas:

[0086] (13)

[0087] Where j is the imaginary unit of the complex phasor, and its value is... ; , These are the complex phasors of the voltages in phases B and C; and Phase B voltage The real and imaginary parts of a complex phasor; and C-phase voltage The real and imaginary parts of a complex phasor; , , These are the complex phasors of the three-phase currents A, B, and C; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor;

[0088] Step 2: Extract the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase voltage and three-phase current through positive-negative-sequence transformation. The expressions are as follows:

[0089] (14)

[0090] Where: a is a basic element of the transformation matrix, and its value , j is the imaginary unit of the complex number, and its value is... ;

[0091] , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase voltage.

[0092] , , These are the three-phase voltage phasors of A, B, and C.

[0093] , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase current.

[0094] , , These are the phasors of the three-phase currents A, B, and C;

[0095] Step 3: Calculate the active and reactive power of the fundamental positive sequence component, as shown in the following expressions:

[0096] (15)

[0097] Where: the subscript "1" represents the fundamental frequency, and the subscript "+" represents positive sequence. and The fundamental positive sequence component of the three-phase voltage The real and imaginary parts, and The fundamental positive sequence component of the three-phase current The real and imaginary parts, P 1+ Q represents the active power of the fundamental positive sequence component. 1+ This represents the reactive power of the fundamental positive sequence component.

[0098] Step 4: Calculate the active and reactive currents of the fundamental positive sequence component, as shown in the following expressions:

[0099] (16)

[0100] in: This represents the active current of the fundamental positive sequence component. This represents the reactive current of the fundamental positive sequence component. It represents the complex modulus of the fundamental positive sequence component of the three-phase voltage.

[0101] A further improvement of the present invention is that the calculation module performs the following calculations:

[0102] For voltage tolerance type adaptive sub-index E tol_v The following five working conditions are determined in sequence:

[0103] Judgment Condition 1: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is between [90% and 110%] of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station are operating normally, then it has voltage deviation tolerance adaptability. At this time, the voltage tolerance adaptability sub-index is E. tol_v_1 E tol_v_1 A value of 1 indicates that the device does not possess voltage deviation tolerance adaptability. tol_v_1 The value is 0;

[0104] Judgment Condition 2: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is as low as 20% of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station can operate continuously for more than 625ms, then it has low voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_2 E tol_v_2 A value of 1 indicates low voltage tolerance capability; otherwise, it lacks this capability. tol_v_2 The value is 0;

[0105] Judgment Condition 3: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [125% and 130%] of the nominal voltage; Corresponding criterion: If all power generation units in the new energy power station can guarantee continuous operation without disconnecting from the grid for 500ms, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_3 E tol_v_3 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_3 The value is 0;

[0106] Judgment Condition 4: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [120%, 125%) of the nominal voltage; Corresponding criterion: If all power generation units in the new energy power station can maintain continuous operation without disconnecting from the grid for 1 second, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_4 E tol_v_4 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_4 The value is 0;

[0107] Condition 5: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [110%, 120%) of the nominal voltage; Corresponding criterion: If all generating units in the new energy power station can maintain continuous operation without disconnecting from the grid for 10 seconds, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_5 E tol_v_5 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_5 The value is 0;

[0108] If any of the above operating conditions fail to meet the corresponding criteria, the new energy power station is deemed to lack voltage tolerance adaptability; the voltage tolerance adaptability sub-index E is calculated according to formula (17). tol_v value:

[0109] (17)

[0110] In the formula, To analyze the voltage tolerance type adaptability sub-index E tol_v Operating condition number, To analyze the voltage tolerance type adaptability sub-index E tol_v The number of working conditions;

[0111] For frequency tolerance-type adaptive sub-index E tol_f The following four working conditions are determined sequentially:

[0112] Judgment Condition 1: The grid frequency f at the grid connection point of the new energy power station is located in [48.5Hz, 50.5Hz]; Corresponding criterion: If all power generation units in the new energy power station operate continuously, it has frequency deviation tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_1 E tol_f_1 A value of 1 indicates that frequency deviation tolerance is not present. tol_f_1 The value is 0;

[0113] Judgment Condition 2: The grid frequency f at the grid connection point of the new energy power station is located in [48Hz, 48.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 minutes each time the frequency is lower than 48.5Hz, then it has low-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_2 E tol_f_2 A value of 1 indicates low-frequency tolerance; otherwise, it lacks adaptability. tol_f_2 The value is 0;

[0114] Judgment Condition 3: The grid frequency f at the grid connection point of the new energy power station is located in (50.5Hz, 51Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 3 minutes, then it has high-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_3 E tol_f_3 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_3 The value is 0;

[0115] Judgment Condition 4: The grid frequency f at the grid connection point of the new energy power station is located in (51Hz, 51.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 seconds each time the frequency is higher than 50.5Hz, then it has high frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_4 E tol_f_4 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_4 The value is 0;

[0116] If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed to lack frequency tolerance adaptability. The frequency tolerance adaptability sub-index E is then calculated according to formula (18). tol_f value;

[0117] (18)

[0118] In the formula, To analyze the frequency tolerance adaptive sub-index E tol_f Operating condition number, Analysis of frequency tolerance-type adaptive sub-indices E tol_f The number of working conditions;

[0119] For the dynamic active power support type sub-indicator E act_p Perform the following operations:

[0120] Calculate the actual droop rate and the actual droop rate deviation of the fast frequency response of new energy sources:

[0121] (19)

[0122] In the formula, k δ% δ% represents the actual droop rate deviation of the new energy fast frequency response, where δ% is the actual droop rate of the new energy fast frequency response. std % represents the droop rate specified for the rapid frequency response of new energy sources, f d The fast frequency response dead zone, measured in Hz, f N The system's rated frequency is in Hz, f is the grid frequency at the new energy power station's grid connection point, and P is the frequency in Hz. N The rated power of the new energy power plant is expressed in MW or P. 1+ 0 The initial value of the active power of the fundamental positive sequence component is given in MW and P. 1+ This represents the active power of the fundamental positive sequence component, expressed in MW.

[0123] Based on the actual droop rate deviation of the fast frequency response of new energy sources, the following two operating conditions are judged:

[0124] Judgment Condition 1: The grid frequency f at the grid connection point of the new energy power station is higher than 50.3Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; Corresponding criterion: The active power of the new energy power station can be calculated according to k δ% The active power reduction should not exceed ±5%, at which point the dynamic active power active support sub-index is E. act_p_1 E act_p_1 The value is 1, otherwise E act_p_1 The value is 0;

[0125] Judgment Condition 2: The grid frequency f at the grid connection point of the new energy power station is lower than 49.97Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; corresponding criterion: the active power of the new energy power station is determined according to k δ% The active power is increased by no more than ±5%, at which point the dynamic active power active support sub-index is E.act_p_2 E act_p_2 The value is 1, otherwise E act_p_2 The value is 0;

[0126] If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed to lack dynamic active power support adaptability; the dynamic active power support type sub-index E is calculated according to formula (20). act_p value:

[0127] (20)

[0128] In the formula, To analyze the dynamic active power support sub-index E act_p Operating condition number, To analyze the dynamic active power support sub-index E act_p The number of working conditions;

[0129] For the transient reactive power active support type sub-index E act_q Perform the following operations:

[0130] Calculate the actual deviation of the reactive power support coefficient for new energy sources:

[0131] (twenty one)

[0132] In the formula, k λ λ represents the actual deviation of the reactive power support coefficient for new energy sources, where λ is the actual reactive power support coefficient. std The recommended value for the reactive power support factor is I. Q1+ I is the reactive current of the fundamental positive sequence component. Q1+ 0 I is the initial value of the reactive current of the fundamental positive sequence component before the fault occurs. N This is the rated value of the fundamental positive sequence reactive current. It represents the complex modulus of the fundamental positive sequence component of the three-phase voltage;

[0133] Based on the actual deviation of the reactive power support coefficient of new energy sources, the following two operating conditions are judged:

[0134] Judgment Condition 1: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is [60%, 80%] of the nominal voltage; Corresponding criterion: The actual deviation of the reactive power support coefficient of the new energy power station is 0 ≤ k λ ≤5%, E act_q_1 The value is 1, otherwise E act_q_1 The value is 0;

[0135] Judgment Condition 2: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is (110%, 130%) of the nominal voltage; corresponding criterion: the actual deviation of the reactive power support coefficient of the energy power station is 0 ≤ kλ ≤5%, E act_q_2 The value is 1, otherwise E act_q_2 The value is 0;

[0136] If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed not to have the adaptability for transient reactive power active support; the transient reactive power active support type sub-index E is obtained according to formula (22). act_q value;

[0137] (twenty two)

[0138] In the formula, To analyze the transient reactive power active support type sub-index E act_q Operating condition number, To analyze the transient reactive power active support type sub-index E act_q The number of working conditions.

[0139] The beneficial effects of this invention are as follows: The system of this invention can analyze the grid-connected adaptability of various grid-connected new energy power stations within the power grid area under the jurisdiction of the master station online. It can perform refined monitoring, analysis, and comprehensive evaluation of passive tolerance-type grid-connected adaptability indicators and active support-type grid-connected adaptability indicators. By combining a distributed computing architecture based on edge computing with the traditional communication architecture of new energy power stations, it effectively solves the problem of large monitoring data volume and difficulty in centralized processing under the grid connection of large-scale new energy power stations. This system has strong engineering practice guidance value, which can greatly improve the grid-connected adaptability analysis capability of existing power grids with large-scale new energy access, provide timely and accurate decision-making information, and assist power grid dispatching and operation personnel in optimizing dispatching. The method of this invention combines network computing, data storage, and advanced applications, which can effectively reduce various losses caused by data transmission and has certain engineering application value. Attached Figure Description

[0140] Figure 1 This is a simplified diagram of the collaborative calculation steps between the scheduling master station and the new energy substation in an embodiment of the present invention;

[0141] Figure 2 This is the gateway-based task distribution and compression return process in this embodiment of the invention;

[0142] Figure 3 This is the information transmission process for a single new energy power station in an embodiment of the present invention;

[0143] Figure 4 This is a schematic diagram of fault ride-through (tolerance-type adaptive index) in an embodiment of the present invention;

[0144] Figure 5 This is a schematic diagram of the high-frequency response (active support type adaptive index) in an embodiment of the present invention;

[0145] Figure 6 This is the calculation process for the active support index in this embodiment of the invention. Detailed Implementation

[0146] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0147] like Figure 1 As shown, the grid-connection adaptability analysis system for new energy power plants of the present invention includes a dispatch master station, multiple new energy substations and an edge gateway, wherein the edge gateway is deployed between the dispatch master station and the new energy substations;

[0148] The scheduling master station distributes computing tasks to multiple new energy substations via the edge gateway, and aggregates the computing results returned by multiple new energy substations to perform grid-connection adaptability analysis.

[0149] The new energy substations execute the assigned computing tasks asynchronously according to the operating conditions;

[0150] The edge gateway distributes the computing tasks assigned by the scheduling master station to each new energy substation, and collects the computing results and cross-sectional information of each new energy substation, compresses and encrypts them, and sends them back to the scheduling master station.

[0151] The grid-connection adaptability analysis method for new energy power plants based on the above system includes the following steps:

[0152] Step S1: The scheduling master station distributes computing tasks via the edge gateway;

[0153] A gateway layer is deployed between the edge computing terminals of the dispatch master station and the new energy substations to distribute tasks. Traditionally, the dispatch master station communicates with the new energy substations using Remote Terminal Units (RTUs). However, due to the large amount of interactive data involved in the grid-connection adaptability analysis of new energy power plants, occupying or changing the communication channels of the original RTUs is costly. Deploying an edge gateway at the new energy aggregation station to relay tasks effectively reduces the management burden on the dispatch master station. Computation tasks include two types: periodic scheduled tasks and randomized triggered tasks. After periodic scheduled tasks are distributed, the edge computing terminals of each new energy substation will periodically report monitoring and analysis results to the background. After randomized triggered tasks are distributed, the edge computing terminals of each new energy substation will immediately enter the corresponding analysis mode, test specific indicators, and report the analysis results.

[0154] In step S2, each new energy substation asynchronously executes calculation tasks according to its operating conditions;

[0155] After receiving a computing task, the edge computing terminal of each new energy substation will execute it according to its characteristics. If it is a periodic, timed task, the edge computing terminal of each new energy substation will start a new computing process service and collect data through the communication module and the measurement and control module for long-term monitoring. If it is a randomized, triggered task, the edge computing terminal will determine whether the operating conditions of each power generation unit in the current power station meet the test conditions. Once the conditions are met, the test will be performed. Since the operating conditions of each new energy substation are not the same, the computing tasks of each new energy substation cannot be guaranteed to be completed simultaneously. That is, the tasks of each new energy substation are generally executed asynchronously.

[0156] The information transmission process of a single new energy power station is as follows: Figure 3 As shown in the figure, the diagram illustrates the communication connections between the edge computing terminal, the on-site dispatching remote control unit (RTU), the on-site power prediction system, the on-site monitoring system, the on-site high-frequency device, and the on-site power unit (PMU) of the new energy substation.

[0157] The edge computing terminal of the new energy substation includes a measurement and control module, a communication module, a cache module, a storage module, and a computing module.

[0158] The measurement and control module is used to acquire the three-phase voltage and three-phase current analog signals of the voltage transformers and current transformers at the grid connection point of the new energy power plant. It extracts the fundamental components and grid frequency of the three-phase voltage and three-phase current by performing Discrete Fourier Transform (DFT) on the instantaneous values ​​of the three-phase voltage and three-phase current. It extracts the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase voltage and three-phase current by performing sequence component transformation on the fundamental components of the three-phase voltage and three-phase current. It obtains the fundamental positive-sequence active power and reactive power by multiplying the fundamental positive-sequence voltage and fundamental positive-sequence current.

[0159] Obtaining electrical quantity information at the grid connection point using a measurement and control module offers higher speed and accuracy than information acquired through a monitoring system. This makes it suitable for calculating indicators requiring high data sampling resolution, such as fault ride-through and fast frequency response. For renewable energy power plants where installing a measurement and control module is not feasible, if the PMU (Power Management Unit) of the renewable energy power plant is clock-synchronized with the edge computing terminal of the renewable energy substation, the PMU can be used instead of the measurement and control module.

[0160] The cache module is used to cache the electrical quantity information of the grid-connected point within the calculation cycle output by the measurement and control module. This information is used by the calculation module and also outputs to the storage module for long-term retention. The cache module can be implemented using large-capacity memory as the hardware carrier, while the storage module can be implemented using a large-capacity solid-state drive.

[0161] The calculation module is used to calculate various indicators of the grid-connected adaptability of new energy power plants, including tolerance-type adaptability indicators and active support-type adaptability indicators, among which: tolerance-type adaptability indicator E tol Including voltage tolerance adaptability sub-index E tol_v and frequency tolerance adaptive sub-index E tol_f Active support-type adaptive index E act Including the dynamic active power support sub-indicator E act_p and transient reactive power active support type sub-indicator E act_q Based on the relevant technical regulations for the connection of new energy power plants to the power system (GB / T 19963 for wind power and GB / T 19964 for photovoltaic power), the operating conditions of new energy power plants (new energy substations) are determined, and various indicators are analyzed through criterion identification. The calculation module can be implemented using a CPU as the hardware carrier.

[0162] The communication module is used for information exchange between the new energy substation and other systems within the substation. Data input for the resilience and active support adaptability indicators includes not only electrical quantity information of the grid connection point obtained through the measurement and control module, but also the operating status of each new energy power generation unit obtained through the monitoring system, the theoretical output of the current power grid obtained through the power prediction system, and AGC / AVC dispatching commands from the dispatching master station obtained through the remote control unit (RTU). Additionally, the communication module sends the calculation results to the edge gateway. The communication module must support multiple industrial communication protocols, including IEC104, Modbus, and PMU.

[0163] The measurement and control module is one of the key modules of the edge computing terminal, and its output accuracy largely determines the accuracy of the grid-connection adaptability analysis results of new energy power plants. The measurement and control module can acquire the three-phase instantaneous voltage and current analog signals at the grid connection point, generate digital signals through analog-to-digital conversion, and then extract the basic electrical quantity information of the grid connection point through digital signal processing algorithms such as Fourier transform and ordinal matrix transform. The specific implementation process is as follows:

[0164] The steps for calculating the fundamental positive sequence component are as follows:

[0165] Step 1: Extract the fundamental component using Fourier transform, as shown in the formula below:

[0166] (1)

[0167] Where: t is time. This represents the instantaneous value of phase A voltage. and Phase A voltage The real and imaginary parts of a complex phasor; , where is the power frequency (i.e., 50Hz), and T is the cycle time window corresponding to the power frequency (i.e., 0.02 seconds).

[0168] Similarly, we can obtain , , , , , , , , , Then, the three-phase voltage and three-phase current phasors are synthesized, as shown in the following formulas:

[0169] (2)

[0170] Where j is the imaginary unit of the complex phasor, and its value is... ; , For the complex phasors of the three-phase voltages B and C; and Phase B voltage The real and imaginary parts of a complex phasor; and C-phase voltage The real and imaginary parts of a complex phasor; , , These are the complex phasors of the three-phase currents A, B, and C; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor.

[0171] Step 2: Extract the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase voltage and three-phase current through positive-negative-sequence transformation. The expressions are as follows:

[0172] (3)

[0173] Where: a is a basic element of the transformation matrix, and its value , j is the imaginary unit of the complex number, and its value is... ;

[0174] , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase voltage.

[0175] , , These are the three-phase voltage phasors of A, B, and C.

[0176] , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase current.

[0177] , , These are the phasors of the three-phase currents A, B, and C;

[0178] Generally, measurement and control modules collect a large amount of data. When performing index analysis, the computational efficiency can be improved by downsampling. In particular, a sampling rate of 1000-2000Hz can well meet the analysis accuracy requirements while significantly improving computational efficiency.

[0179] Step 3: Calculate the active and reactive power of the fundamental positive sequence component, as shown in the formula below:

[0180] (4)

[0181] Where: the subscript "1" represents the fundamental frequency, and the subscript "+" represents positive sequence. and The fundamental positive sequence component of the three-phase voltage The real and imaginary parts, and The positive sequence component of the three-phase current The real and imaginary parts, P 1+ Q represents the active power of the fundamental positive sequence component. 1+ This represents the reactive power of the fundamental positive sequence component.

[0182] Step 4: Calculate the active and reactive currents of the fundamental positive sequence component, as shown in the following expressions:

[0183] (5)

[0184] Among them: I P1+ I is the active current of the fundamental positive sequence component. Q1+ This represents the reactive current of the fundamental positive sequence component. It is the complex modulus of the positive-sequence voltage phasor.

[0185] The computing module is another key module of the edge computing terminal, and its tolerance indicators include the voltage tolerance adaptability sub-indicator E. tol_v and frequency tolerance adaptive sub-index E tol_f The voltage tolerance adaptability sub-index E tol_vTaking this as an example, it can be further divided into steady-state voltage deviation adaptability index and transient voltage adaptability index. The steady-state voltage deviation adaptability index refers to the ability of a new energy power station to operate normally for a long time within a range of ±10% of the rated voltage deviation; the transient voltage adaptability index refers to whether a new energy power station can maintain operation without disconnecting from the grid for a short period of time when the voltage transiently drops or rises, that is, it should have a certain fault voltage ride-through capability. Figure 4 This means that new energy power plants must be able to operate continuously without disconnecting from the grid for at least 625ms when a voltage drop is caused by a grid fault. The specific analysis of the tolerance and adaptability indicators is as follows:

[0186] For voltage tolerance type adaptive sub-index E tol_v The following five working conditions are determined in sequence:

[0187] Judgment Condition 1: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is between [90% and 110%] of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station are operating normally, then it has voltage deviation tolerance adaptability. At this time, the voltage tolerance adaptability sub-index is E. tol_v_1 E tol_v_1 A value of 1 indicates that the device does not possess voltage deviation tolerance adaptability. tol_v_1 The value is 0;

[0188] Judgment Condition 2: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is as low as 20% of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station can operate continuously for more than 625ms, then it has low voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_2 E tol_v_2 A value of 1 indicates low voltage tolerance capability; otherwise, it lacks this capability. tol_v_2 The value is 0;

[0189] Judgment Condition 3: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [125% and 130%] of the nominal voltage; Corresponding criterion: If all power generation units in the new energy power station can guarantee continuous operation without disconnecting from the grid for 500ms, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_3 E tol_v_3 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_3 The value is 0;

[0190] Judgment Condition 4: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [120%, 125%) of the nominal voltage; Corresponding criterion: If all power generation units in the new energy power station can maintain continuous operation without disconnecting from the grid for 1 second, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_4 E tol_v_4A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_4 The value is 0;

[0191] Condition 5: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [110%, 120%) of the nominal voltage; Corresponding criterion: If all generating units in the new energy power station can maintain continuous operation without disconnecting from the grid for 10 seconds, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_5 E tol_v_5 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_5 The value is 0;

[0192] If any of the above operating conditions fail to meet the corresponding criteria, the new energy power station is deemed to lack voltage withstand adaptability; the voltage withstand adaptability sub-index E is calculated according to formula (6). tol_v value:

[0193] (6)

[0194] In the formula, To analyze the voltage tolerance type adaptability sub-index E tol_v Operating condition number, To analyze the voltage tolerance type adaptability sub-index E tol_v The number of working conditions;

[0195] For frequency tolerance-type adaptive sub-index E tol_f The following four working conditions are determined sequentially:

[0196] Judgment Condition 1: The grid frequency f at the grid connection point of the new energy power station is located in [48.5Hz, 50.5Hz]; Corresponding criterion: If all power generation units in the new energy power station operate continuously, it has frequency deviation tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_1 E tol_f_1 A value of 1 indicates that frequency deviation tolerance is not present. tol_f_1 The value is 0;

[0197] Judgment Condition 2: The grid frequency f at the grid connection point of the new energy power station is located in [48Hz, 48.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 minutes each time the frequency is lower than 48.5Hz, then it has low-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_2 E tol_f_2 A value of 1 indicates low-frequency tolerance; otherwise, it lacks adaptability. tol_f_2 The value is 0;

[0198] Judgment Condition 3: The grid frequency f at the grid connection point of the new energy power station is located in (50.5Hz, 51Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 3 minutes, then it has high-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_3 E tol_f_3 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_3 The value is 0;

[0199] Judgment Condition 4: The grid frequency f at the grid connection point of the new energy power station is located in (51Hz, 51.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 seconds each time the frequency is higher than 50.5Hz, then it has high frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_4 E tol_f_4 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_4 The value is 0;

[0200] If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed to lack frequency tolerance adaptability. The frequency tolerance adaptability sub-index E is then calculated according to formula (7). tol_f value;

[0201] (7)

[0202] In the formula, To analyze the frequency tolerance adaptive sub-index E tol_f Operating condition number, Analysis of frequency tolerance-type adaptive sub-indices E tol_f The number of working conditions.

[0203] Analysis of dynamic active support sub-indicator E act_p :

[0204] New energy (photovoltaic power plants, wind farms) power plants utilize corresponding active power control systems, single units, or additional independent control devices to achieve active power-frequency droop characteristic control, enabling them to participate in rapid grid frequency adjustment at the grid connection point. Their active power injection support capability is reflected by the droop rate, which is calculated using formula (8) to obtain the droop rate of rapid frequency response:

[0205] (8)

[0206] k δ% The deviation of the actual droop rate for the rapid frequency response of new energy sources;

[0207] δ% represents the actual droop rate of the fast frequency response of new energy sources;

[0208] δ std% is the regulation rate for rapid frequency response of new energy (3% for photovoltaic power plants and 2% for wind farms).

[0209] f d To ensure a fast frequency response dead zone, Hz (±0.06Hz for photovoltaic power plants and ±0.10Hz for wind farms);

[0210] f N The system's rated frequency, in Hz;

[0211] P N The rated power of the new energy power plant is expressed in MW.

[0212] P 1+ 0 Let be the initial value of the active power of the fundamental positive sequence component, in MW;

[0213] P 1+ Let be the active power of the fundamental positive sequence component, expressed in MW.

[0214] Specifically, two working conditions are involved:

[0215] Judgment Condition 1: The grid frequency at the grid connection point of the new energy power station is higher than 50.3Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; Corresponding criterion: The active power of the new energy power station can be adjusted according to a certain droop rate (k δ% (No more than ±5%) Fast (response lag time t) hx No more than 2 seconds; response time t 0.9 Wind power should not exceed 12 seconds, and solar power should not exceed 5 seconds; regulation time t s Reduce active power (within 15 seconds), E act_p_1 The value is 1, otherwise E act_p_1 The value is 0;

[0216] Judgment Condition 2: The grid frequency at the grid connection point of the new energy power station is below 49.97Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; Corresponding criterion: The active power of the new energy power station is adjusted according to a certain droop rate (k δ% (No more than ±5%) Fast (response lag time t) hx No more than 2 seconds; response time t 0.9 Wind power should not exceed 12 seconds, and solar power should not exceed 5 seconds; regulation time t s Increase active power (within 15 seconds), E act_p_2 The value is 1, otherwise E act_p_2 The value is 0; if any of the above conditions are not met, the new energy power station is deemed not to have dynamic active power support adaptability; according to formula (9), the dynamic active power support type sub-index E is obtained. act_p value:

[0217] (9)

[0218] In the formula, To analyze the dynamic active power support sub-index E act_p Operating condition number, To analyze the dynamic active power support sub-index E act_p The number of working conditions.

[0219] Analysis of the transient reactive power active support type sub-index E act_q :

[0220] When a power system fault occurs and the three-phase voltage at the grid connection point drops, and the fundamental positive sequence component of the three-phase voltage is at [60%, 80%] or [110%, 130%] of the nominal voltage, the renewable energy power generation station has dynamic reactive power support capability.

[0221] (10)

[0222] k λ The actual deviation of the reactive power support coefficient for new energy sources;

[0223] λ is the actual coefficient of reactive power support;

[0224] λ std The recommended value for the reactive power support coefficient is generally between 1.5 and 3.

[0225] I Q1+ This is the fundamental positive sequence reactive current;

[0226] I Q1+ 0 The initial value of the fundamental positive sequence reactive current before the fault occurs;

[0227] I N This is the rated value of the fundamental positive sequence reactive current.

[0228] Specifically, two working conditions are involved:

[0229] Judgment Condition 1: The fundamental positive sequence voltage at the grid connection point of the new energy power station is [60%, 80%] of the nominal voltage; Corresponding criterion: The actual deviation of the reactive power support coefficient of the new energy power station is 0 ≤ k λ ≤5%, E act_q_1 The value is 1, otherwise E act_q_1 The value is 0;

[0230] Judgment Condition 2: The fundamental positive sequence voltage at the grid connection point of the new energy power station is [110%, 130%] of the nominal voltage; Corresponding criterion: The actual deviation of the reactive power support coefficient of the energy power station is 0 ≤ k λ ≤5%, E act_q_2 The value is 1, otherwise Eact_q_2 The value is 0;

[0231] If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed not to have the adaptability for transient reactive power active support; the transient reactive power active support type sub-index E is obtained according to formula (11). act_q value;

[0232] (11)

[0233] In the formula, To analyze the transient reactive power active support type sub-index E act_q Operating condition number, To analyze the transient reactive power active support type sub-index E act_q The number of working conditions.

[0234] Dynamic active support type sub-indicator E act_p Taking this as an example, its calculation flowchart is as follows: Figure 6 As shown, specifically:

[0235] First, the scheduling master station generates a frequency test sequence f to simulate power grid frequency disturbances. moc Frequency test sequence f moc The computation task is sent to the new energy substation via the edge gateway. After receiving the computation task, the new energy substation adjusts the control mode of the high-frequency device within the station to the test state through the communication module, and sends the frequency test sequence f. moc The signal is sent to the high-frequency control device within the station, triggering high-frequency control and recording the trigger time. This information is subsequently fed back to the dispatch master station via a 104 message. On the other hand, the active power of the fundamental positive-sequence component is obtained through the measurement and control module (as shown in Equation 3), and based on... Figure 5 Dynamic active power support type sub-indicator E act_p analyze, Figure 5 This includes the response lag time t hx : The time required from the start of frequency crossing the frequency regulation dead zone of the new energy power plant until the power generation output reliably begins to change in the frequency regulation direction; response time t 0.9 The adjustment time t is the time required from the start of frequency exceeding the frequency modulation dead zone until the active power adjustment reaches 90% of the difference between the frequency modulation target value and the initial power. s This includes the shortest time from when the frequency exceeds the frequency regulation dead zone until the active power stabilizes (power fluctuation does not exceed ±5% of rated output). Simultaneously, the analysis requires power prediction information from new energy power plants and AGC (Automatic Generation Control) instructions from the power grid dispatching system, which need to be obtained through communication modules interacting with the station's remote control unit (RTU) and the station's power prediction system.

[0236] When analyzing tolerance-type adaptability indicators online, it is necessary to monitor the operation of the new energy substations over a long period of time and analyze their adaptability by statistically analyzing the monitoring data under various operating conditions. In addition to long-term operational monitoring, active support-type adaptability indicators can also be analyzed and evaluated periodically through detection by the main dispatch station. Figure 6 In the mode of main station detection, online analysis and calculation are achieved through interaction with new energy substations.

[0237] Step S3: The edge gateway collects the computing terminal results and cross-sectional information of each substation, compresses and encrypts them, and sends them back.

[0238] The edge gateway is located between the new energy substation and the dispatch master station, providing a convenient and fast data transmission mode. Due to the introduction of the edge gateway, the entire system architecture is divided into three layers: the new energy substation, the edge gateway, and the dispatch master station as a centralized data processing center.

[0239] Each renewable energy substation packages its grid-connection adaptability analysis calculation results and key operational characteristics (including total active power, total reactive power, theoretical power prediction data, voltage and frequency at the main transformer's high-voltage side grid connection point, and operational status of each generating unit) into a data package and sends it to the edge gateway. The edge gateway waits for the results from all renewable energy substations within a calculation task cycle before compressing and transmitting the data from its multiple substations back. This data aggregation at the aggregation station level effectively reduces the data aggregation pressure on the main dispatch station. The edge computing terminals at the renewable energy substations store raw data at the power station level, effectively reducing the data storage pressure on the main dispatch station. The raw data is not transmitted on a large scale over the network, reducing communication transmission pressure and providing data security protection.

[0240] To ensure the comprehensiveness and convenience of the data, while distinguishing it from other data in the power grid and guaranteeing the safe operation of the power grid, the real-time operating data of each new energy power station needs to be compressed and encrypted through the gateway before being transmitted to the main station to meet information security requirements. Data encryption transmission needs to be completed in the form of keys to avoid information leakage or tampering.

[0241] Step S4: The scheduling master station aggregates the backhaul results from multiple substations and performs a grid-connected adaptability analysis.

[0242] The dispatch master station interacts with each edge gateway to perform grid-connection adaptability analysis on each renewable energy substation within its jurisdiction. The dispatch master station obtains calculation results from each edge gateway and PMU monitoring data from each substation via the master dispatch WAMS system. PMU data typically has a longer retention period than data collected by the measurement and control module. After identifying substations with poor adaptability through online monitoring at the edge gateways, the dispatch master station performs a post-evaluation by reviewing the PMU data stored in the WAMS system, which improves the accuracy of grid-connection adaptability analysis for renewable energy power plants.

[0243] The dispatching master station aggregates the calculation results sent from the edge computing terminals of multiple renewable energy substations within its jurisdiction via the edge gateway, and performs classification and statistical analysis of various sub-indicators of grid connection adaptability. It sorts the grid connection adaptability calculation results of different power stations at the renewable energy base level, identifies and marks power stations with poor adaptability based on the sorting results, and implements targeted emergency measures for different renewable energy power stations if anomalies are detected, thereby improving the grid frequency control level. It also provides auxiliary decision-making suggestions for dispatching and operation personnel.

[0244] The task distribution and compressed data transmission process based on the edge gateway is as follows: Figure 2 As shown, the dispatch master station distributes computing tasks to the edge computing terminals of each new energy substation through the edge gateway. The edge computing terminals of the new energy substations perform grid-connection adaptability monitoring and analysis based on the computing tasks and the current operating conditions of the power station, and send the computing results back to the edge gateway. Since the operating conditions of each new energy power station are different, the tasks may not be completed at the same time. Therefore, the gateway needs to collect all the computing tasks in this round, compress and encrypt the data in a unified manner, and finally send the computing results back to the dispatch master station for comprehensive evaluation.

[0245] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0246] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims.

Claims

1. A method for analyzing the grid-connected adaptability of new energy power plants, characterized in that: The method includes: The scheduling master station distributes computing tasks through the edge gateway; Each new energy substation executes the computing task asynchronously according to its operating conditions after receiving the computing task; After the calculation task is completed, each new energy substation compresses and encrypts the calculation results and cross-section information through the edge gateway and sends them back to the dispatch master station. The dispatch master station performs grid-connection adaptability analysis based on the returned results. The specific operations of each new energy substation asynchronously executing the computing task according to its operating conditions after receiving the computing task are as follows: Step a1: Collect the three-phase voltage and three-phase current analog signals of the voltage transformer and current transformer at the grid connection point of the new energy power station. Through analog-to-digital conversion and digital signal processing technology, extract the grid frequency f, the fundamental positive / negative / zero sequence components of the three-phase voltage, the fundamental positive / negative / zero sequence components of the three-phase current, the active power and reactive power of the fundamental positive sequence component, and the active current and reactive current of the fundamental positive sequence component. Step a2: Based on the grid frequency, fundamental positive / negative / zero sequence components of the three-phase voltage, fundamental positive / negative / zero sequence components of the three-phase current, fundamental positive sequence active power, reactive power, and active and reactive current of the fundamental positive sequence component extracted in Step 1, calculate various indicators of grid-connected adaptability of new energy power plants, including tolerance-type adaptability indicators and active support-type adaptability indicators. The active support type adaptive index E in a2 tol Including the dynamic active power support sub-indicator E act_p and transient reactive power active support type sub-index E act_q The specific calculation process is as follows: Step a23, analyze the dynamic active power support sub-index E act_p ; The deviation between the actual droop rate and the actual droop rate for the fast frequency response of new energy sources is: （8） In the formula, k δ% δ% represents the actual droop rate deviation of the new energy fast frequency response, where δ% is the actual droop rate of the new energy fast frequency response. std % represents the droop rate specified for the rapid frequency response of new energy sources, f d The fast frequency response dead zone, measured in Hz, f N The system's rated frequency is in Hz, f is the grid frequency at the new energy power station's grid connection point, and P is the frequency in Hz. N The rated power of the new energy power plant is expressed in MW or P. 1+ 0 The initial value of the active power of the fundamental positive sequence component is given in MW and P. 1+ This represents the active power of the fundamental positive sequence component, expressed in MW. Based on the actual droop rate deviation of the fast frequency response of the new energy source, the following two operating conditions are analyzed: Judgment Condition 1: The grid frequency f at the grid connection point of the new energy power station is higher than 50.3Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; Corresponding criterion: The active power of the new energy power station can be calculated according to k δ% The active power reduction should not exceed ±5%, at which point the dynamic active power active support sub-index is E. act_p_1 E act_p_1 The value is 1, otherwise E act_p_1 The value is 0; Judgment Condition 2: The grid frequency f at the grid connection point of the new energy power station is lower than 49.97Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; corresponding criterion: the active power of the new energy power station is determined according to k δ% The active power is increased by no more than ±5%, at which point the dynamic active power active support sub-index is E. act_p_2 E act_p_2 The value is 1, otherwise E act_p_2 The value is 0; If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed to lack dynamic active power support adaptability; the dynamic active power support type sub-index E is calculated according to formula (9). act_p value: （9） In the formula, To analyze the dynamic active power support type sub-index E act_p Operating condition number, To analyze the dynamic active power support type sub-index E act_p The number of working conditions; Step a24, analyze the transient reactive power active support type sub-index E act_q ; The actual deviation of the reactive power support coefficient for new energy sources is calculated as follows: （10） In the formula, k λ λ represents the actual deviation of the reactive power support coefficient for new energy sources, where λ is the actual reactive power support coefficient. std The recommended value for the reactive power support factor is I. Q1+ I is the reactive current of the fundamental positive sequence component. Q1+ 0 I is the initial value of the reactive current of the fundamental positive sequence component before the fault occurs. N This is the rated value of the fundamental positive sequence reactive current. It represents the complex modulus of the fundamental positive sequence component of the three-phase voltage; Based on the actual deviation of the reactive power support coefficient of new energy sources, the following two operating conditions are analyzed: Judgment Condition 1: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is [60%, 80%] of the nominal voltage; Corresponding criterion: The actual deviation of the reactive power support coefficient of the new energy power station is 0 ≤ k λ ≤5%, E act_q_1 The value is 1, otherwise E act_q_1 The value is 0; Judgment Condition 2: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is (110%, 130%) of the nominal voltage; corresponding criterion: the actual deviation of the reactive power support coefficient of the energy power station is 0 ≤ k λ ≤5%, E act_q_2 The value is 1, otherwise E act_q_2 The value is 0; If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed not to have the adaptability for transient reactive power active support; the transient reactive power active support type sub-index E is obtained according to formula (11). act_q value; （11） In the formula, To analyze the transient reactive power active support type sub-index E act_q Operating condition number, To analyze the transient reactive power active support type sub-index E act_q The number of working conditions.

2. The grid-connection adaptability analysis method for new energy power plants according to claim 1, characterized in that: The computational tasks include periodic timed tasks and randomized triggering tasks.

3. The grid-connection adaptability analysis method for new energy power plants according to claim 1, characterized in that: In step a1, the specific steps for extracting the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase voltage, the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase current, the active power and reactive power of the fundamental positive-sequence component, and the active and reactive current of the fundamental positive-sequence component are as follows: Step a11: Extract the fundamental component using Fourier transform. The extraction process is as follows: （1） Where: t is time. This represents the instantaneous value of phase A voltage. and Phase A voltage The real and imaginary parts of a complex phasor Where is the power frequency, and T is the cycle time window corresponding to the power frequency; Similarly, we can obtain , , , , , , , , , Furthermore, the three-phase voltage and three-phase current phasors are synthesized using the following formulas: （2） Where j is the imaginary unit of the complex phasor, and its value is... ; , These are the complex phasors of the voltages in phases B and C; and Phase B voltage The real and imaginary parts of a complex phasor; and C-phase voltage The real and imaginary parts of a complex phasor; , , These are the complex phasors of the three-phase currents A, B, and C; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor; Step a12: Extract the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase voltage and three-phase current through positive-negative-sequence transformation. The expressions are as follows: （3） Where: a is a basic element of the transformation matrix, and its value , j is the imaginary unit of the complex number, and its value is... ; , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase voltage. , , These are the three-phase voltage phasors of A, B, and C; , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase current. , , These are the phasors of the three-phase currents A, B, and C; Step a13: Calculate the active and reactive power of the fundamental positive sequence component, as shown in the following expressions: （4） Where: the subscript "1" indicates the fundamental frequency of the power frequency, and the subscript "+" indicates positive sequence. and The fundamental positive sequence component of the three-phase voltage The real and imaginary parts, and The fundamental positive sequence component of the three-phase current The real and imaginary parts, P 1+ Q represents the active power of the fundamental positive sequence component. 1+ This represents the reactive power of the fundamental positive sequence component. Step a14: Calculate the active and reactive currents of the fundamental positive sequence component, as shown in the following expressions: （5） in: This represents the active current of the fundamental positive sequence component. This represents the reactive current of the fundamental positive sequence component. for The complex modulus of the fundamental positive sequence component of the three-phase voltage.

4. The grid-connection adaptability analysis method for new energy power plants according to claim 1, characterized in that: The tolerance-type adaptability index in step a2 includes the voltage tolerance-type adaptability sub-index E. tol_v and frequency tolerance adaptive sub-index E tol_f The specific analysis process is as follows: Step a21, targeting the voltage tolerance type adaptability sub-index E tol_v The following five working conditions are determined in sequence: Judgment Condition 1: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is between [90% and 110%] of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station are operating normally, then it has voltage deviation tolerance adaptability. At this time, the voltage tolerance adaptability sub-index is E. tol_v_1 E tol_v_1 A value of 1 indicates that the device does not possess voltage deviation tolerance adaptability. tol_v_1 The value is 0; Judgment Condition 2: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is as low as 20% of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station can operate continuously for more than 625ms, then it has low voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_2 E tol_v_2 A value of 1 indicates low voltage tolerance capability; otherwise, it lacks this capability. tol_v_2 The value is 0; Condition 3: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [125% and 130%] of the nominal voltage; Corresponding criterion: If all power generation units in the new energy power station can maintain continuous operation without disconnecting from the grid for 500ms, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_3 E tol_v_3 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_3 The value is 0; Condition 4: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [120% and 125%] of the nominal voltage; corresponding criterion: if all power generation units in the new energy power station can maintain continuous operation without disconnecting from the grid for 1 second, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_4 E tol_v_4 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_4 The value is 0; Judgment Condition 5: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [110%, 120%) of the nominal voltage; Corresponding criterion: If all generating units in the new energy power station can maintain continuous operation without disconnecting from the grid for 10 seconds, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_5 E tol_v_5 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_5 The value is 0; If any of the above operating conditions fail to meet the corresponding criteria, the new energy power station is deemed to lack voltage withstand adaptability; the voltage withstand adaptability sub-index E is calculated according to formula (6). tol_v value: （6） In the formula, To analyze the voltage tolerance type adaptability sub-index E tol_v Operating condition number, To analyze the voltage tolerance type adaptability sub-index E tol_v The number of working conditions; Step a22, targeting the frequency tolerance adaptive sub-index E tol_f The following four working conditions are determined sequentially: Judgment Condition 1: The grid frequency f at the grid connection point of the new energy power station is located in [48.5Hz, 50.5Hz]; Corresponding criterion: If all power generation units in the new energy power station operate continuously, it has frequency deviation tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_1 E tol_f_1 A value of 1 indicates that frequency deviation tolerance is not present. tol_f_1 The value is 0; Judgment Condition 2: The grid frequency f at the grid connection point of the new energy power station is located in [48Hz, 48.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 minutes each time the frequency is lower than 48.5Hz, then it has low-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_2 E tol_f_2 A value of 1 indicates low-frequency tolerance; otherwise, it lacks adaptability. tol_f_2 The value is 0; Judgment Condition 3: The grid frequency f at the grid connection point of the new energy power station is located in (50.5Hz, 51Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 3 minutes, then it has high-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_3 E tol_f_3 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_3 The value is 0; Judgment Condition 4: The grid frequency f at the grid connection point of the new energy power station is located in (51Hz, 51.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 seconds each time the frequency is higher than 50.5Hz, then it has high frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_4 E tol_f_4 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_4 The value is 0; If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed to lack frequency tolerance adaptability. The frequency tolerance adaptability sub-index E is then calculated according to formula (7). tol_f value; （7） In the formula, To analyze the frequency tolerance adaptive sub-index E tol_f Operating condition number, Analysis of frequency tolerance adaptive sub-indices E tol_f The number of working conditions.

5. A new energy power plant grid-connection adaptability analysis system based on the method of any one of claims 1 to 4, characterized in that: It includes a dispatch master station, multiple new energy substations and an edge gateway, wherein the edge gateway is deployed between the dispatch master station and the new energy substations; The scheduling master station distributes computing tasks to multiple new energy substations via the edge gateway, and aggregates the computing results returned by multiple new energy substations to perform grid-connection adaptability analysis. The new energy substations execute the assigned computing tasks asynchronously according to the operating conditions; The edge gateway distributes the computing tasks assigned by the scheduling master station to each new energy substation, and collects the computing results and cross-sectional information of each new energy substation, compresses and encrypts them, and sends them back to the scheduling master station.

6. The grid-connection adaptability analysis system for a new energy power plant according to claim 5, characterized in that: The new energy substation includes a measurement and control module, a communication module, a high-speed cache module, a storage module, and a computing module; The measurement and control module is used to collect the three-phase voltage and three-phase current analog signals of the voltage transformer and current transformer at the grid connection point of the new energy power station. Through analog-to-digital conversion and digital signal processing technology, it extracts the electrical quantity information of the grid connection point of the new energy power station and stores the results in the high-speed cache module. The electrical quantity information of the grid connection point of the new energy power station includes the grid frequency, the fundamental positive sequence / negative sequence / zero sequence components of the three-phase voltage, the fundamental positive sequence / negative sequence / zero sequence components of the three-phase current, the fundamental positive sequence active power, reactive power, and the active current and reactive current of the fundamental positive sequence component. The high-speed cache module is used to cache the electrical quantity information of the grid-connected point of the new energy power plant within the calculation cycle output by the measurement and control module. On the one hand, it is used by the calculation module, and on the other hand, it outputs the data to the storage module for long-term storage. The calculation module receives electrical quantity information of the grid connection point of the new energy power plant cached in the cache module, and calculates various indicators of the grid connection adaptability of the new energy power plant. These indicators include tolerance-type adaptability indicators and active support-type adaptability indicators. The tolerance-type adaptability indicators include the voltage tolerance-type adaptability sub-indicator E. tol_v and frequency tolerance adaptive sub-index E tol_f Active support-type adaptive indicators include the dynamic active power active support sub-indicator E. act_p and transient reactive power active support type sub-index E act_q ; The communication module is used for information exchange between the new energy substation and other systems, including monitoring systems, power prediction systems, remote control units (RTUs), and edge gateways.

7. The grid-connection adaptability analysis system for a new energy power plant according to claim 6, characterized in that: The measurement and control module performs the following operations: Step 1: Extract the fundamental component using Fourier transform. The extraction process is as follows: （12） Where: t is time. This represents the instantaneous value of phase A voltage. and Phase A voltage The real and imaginary parts of a complex phasor Where is the power frequency, and T is the cycle time window corresponding to the power frequency; Similarly, we can obtain , , , , , , , , , Furthermore, the three-phase voltage and three-phase current phasors are synthesized using the following formulas: （13） Where j is the imaginary unit of the complex phasor, and its value is... ; , These are the complex phasors of the voltages in phases B and C; and Phase B voltage The real and imaginary parts of a complex phasor; and C-phase voltage The real and imaginary parts of a complex phasor; , , These are the complex phasors of the three-phase currents A, B, and C; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor; and Phase A current The real and imaginary parts of a complex phasor; Step 2: Extract the fundamental positive-sequence / negative-sequence / zero-sequence components of the three-phase voltage and three-phase current through positive-negative-sequence transformation. The expressions are as follows: （14） Where: a is a basic element of the transformation matrix, and its value , j is the imaginary unit of the complex number, and its value is... ; , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase voltage. , , These are the three-phase voltage phasors of A, B, and C; , , These are the fundamental positive-sequence component, negative-sequence component, and zero-sequence component of the three-phase current. , , These are the phasors of the three-phase currents A, B, and C; Step 3: Calculate the active and reactive power of the fundamental positive sequence component, as shown in the following expressions: （15） Where: the subscript "1" indicates the fundamental frequency of the power frequency, and the subscript "+" indicates positive sequence. and The fundamental positive sequence component of the three-phase voltage The real and imaginary parts, and The fundamental positive sequence component of the three-phase current The real and imaginary parts, P 1+ Q represents the active power of the fundamental positive sequence component. 1+ This represents the reactive power of the fundamental positive sequence component. Step 4: Calculate the active and reactive currents of the fundamental positive sequence component, as shown in the following expressions: （16） in: This represents the active current of the fundamental positive sequence component. This represents the reactive current of the fundamental positive sequence component. for The complex modulus of the fundamental positive sequence component of the three-phase voltage.

8. The grid-connection adaptability analysis system for a new energy power plant according to claim 7, characterized in that: The calculation module performs the following calculations: For voltage tolerance type adaptive sub-index E tol_v The following five working conditions are determined in sequence: Judgment Condition 1: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is between [90% and 110%] of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station are operating normally, then it has voltage deviation tolerance adaptability. At this time, the voltage tolerance adaptability sub-index is E. tol_v_1 E tol_v_1 A value of 1 indicates that the device does not possess voltage deviation tolerance adaptability. tol_v_1 The value is 0; Judgment Condition 2: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is as low as 20% of the nominal voltage; Corresponding criterion: If all new energy power generation units in the new energy power station can operate continuously for more than 625ms, then it has low voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_2 E tol_v_2 A value of 1 indicates low voltage tolerance capability; otherwise, it lacks this capability. tol_v_2 The value is 0; Condition 3: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [125% and 130%] of the nominal voltage; Corresponding criterion: If all power generation units in the new energy power station can maintain continuous operation without disconnecting from the grid for 500ms, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_3 E tol_v_3 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_3 The value is 0; Condition 4: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [120% and 125%] of the nominal voltage; corresponding criterion: if all power generation units in the new energy power station can maintain continuous operation without disconnecting from the grid for 1 second, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_4 E tol_v_4 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_4 The value is 0; Judgment Condition 5: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station rises to between [110%, 120%) of the nominal voltage; Corresponding criterion: If all generating units in the new energy power station can maintain continuous operation without disconnecting from the grid for 10 seconds, then it has high voltage withstand adaptability. At this time, the voltage withstand adaptability sub-index is E. tol_v_5 E tol_v_5 A value of 1 indicates high pressure tolerance; otherwise, the device lacks adaptability. tol_v_5 The value is 0; If any of the above operating conditions fail to meet the corresponding criteria, the new energy power station is deemed to lack voltage withstand adaptability; the voltage withstand adaptability sub-index E is calculated according to formula (17). tol_v value: （17） In the formula, To analyze the voltage tolerance type adaptability sub-index E tol_v Operating condition number, To analyze the voltage tolerance type adaptability sub-index E tol_v The number of working conditions; For frequency tolerance-type adaptive sub-index E tol_f The following four working conditions are determined sequentially: Judgment Condition 1: The grid frequency f at the grid connection point of the new energy power station is located in [48.5Hz, 50.5Hz]; Corresponding criterion: If all power generation units in the new energy power station operate continuously, it has frequency deviation tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_1 E tol_f_1 A value of 1 indicates that frequency deviation tolerance is not present. tol_f_1 The value is 0; Judgment Condition 2: The grid frequency f at the grid connection point of the new energy power station is located in [48Hz, 48.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 minutes each time the frequency is lower than 48.5Hz, then it has low-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_2 E tol_f_2 A value of 1 indicates low-frequency tolerance; otherwise, it lacks adaptability. tol_f_2 The value is 0; Judgment Condition 3: The grid frequency f at the grid connection point of the new energy power station is located in (50.5Hz, 51Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 3 minutes, then it has high-frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_3 E tol_f_3 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_3 The value is 0; Judgment Condition 4: The grid frequency f at the grid connection point of the new energy power station is located in (51Hz, 51.5Hz); Corresponding criterion: If all power generation units in the new energy power station have the ability to operate for at least 30 seconds each time the frequency is higher than 50.5Hz, then it has high frequency tolerance adaptability. At this time, the frequency tolerance adaptability sub-index is E. tol_f_4 E tol_f_4 A value of 1 indicates high-frequency tolerance; otherwise, it lacks adaptability. tol_f_4 The value is 0; If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed to lack frequency tolerance adaptability. The frequency tolerance adaptability sub-index E is then calculated according to formula (18). tol_f value; （18） In the formula, To analyze the frequency tolerance adaptive sub-index E tol_f Operating condition number, Analysis of frequency tolerance adaptive sub-indices E tol_f The number of working conditions; For the dynamic active power support type sub-indicator E act_p Perform the following operations: Calculate the actual droop rate and the actual droop rate deviation of the fast frequency response of new energy sources: （19） In the formula, k δ% δ% represents the actual droop rate deviation of the new energy fast frequency response, where δ% is the actual droop rate of the new energy fast frequency response. std % represents the droop rate specified for the rapid frequency response of new energy sources, f d The fast frequency response dead zone, measured in Hz, f N The system's rated frequency is in Hz, f is the grid frequency at the new energy power station's grid connection point, and P is the frequency in Hz. N The rated power of the new energy power plant is expressed in MW or P. 1+ 0 The initial value of the active power of the fundamental positive sequence component is given in MW and P. 1+ This represents the active power of the fundamental positive sequence component, expressed in MW. Based on the actual droop rate deviation of the fast frequency response of new energy sources, the following two operating conditions are judged: Judgment Condition 1: The grid frequency f at the grid connection point of the new energy power station is higher than 50.3Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; Corresponding criterion: The active power of the new energy power station can be calculated according to k δ% The active power reduction should not exceed ±5%, at which point the dynamic active power active support sub-index is E. act_p_1 E act_p_1 The value is 1, otherwise E act_p_1 The value is 0; Judgment Condition 2: The grid frequency f at the grid connection point of the new energy power station is lower than 49.97Hz and the fundamental positive sequence voltage is between [90% and 110%] of the nominal voltage; corresponding criterion: the active power of the new energy power station is determined according to k δ% The active power is increased by no more than ±5%, at which point the dynamic active power active support sub-index is E. act_p_2 E act_p_2 The value is 1, otherwise E act_p_2 The value is 0; If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed to lack dynamic active power support adaptability; the dynamic active power support type sub-index E is calculated according to formula (20). act_p value: （20） In the formula, To analyze the dynamic active power support type sub-index E act_p Operating condition number, To analyze the dynamic active power support type sub-index E act_p The number of working conditions; For the transient reactive power active support type sub-index E act_q Perform the following operations: Calculate the actual deviation of the reactive power support coefficient for new energy sources: （21） In the formula, k λ λ represents the actual deviation of the reactive power support coefficient for new energy sources, where λ is the actual reactive power support coefficient. std The recommended value for the reactive power support factor is I. Q1+ I is the reactive current of the fundamental positive sequence component. Q1+ 0 I is the initial value of the reactive current of the fundamental positive sequence component before the fault occurs. N This is the rated value of the fundamental positive sequence reactive current. It represents the complex modulus of the fundamental positive sequence component of the three-phase voltage; Based on the actual deviation of the reactive power support coefficient of new energy sources, the following two operating conditions are judged: Judgment Condition 1: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is [60%, 80%] of the nominal voltage; Corresponding criterion: The actual deviation of the reactive power support coefficient of the new energy power station is 0 ≤ k λ ≤5%, E act_q_1 The value is 1, otherwise E act_q_1 The value is 0; Judgment Condition 2: The fundamental positive sequence component of the three-phase voltage at the grid connection point of the new energy power station is (110%, 130%) of the nominal voltage; corresponding criterion: the actual deviation of the reactive power support coefficient of the energy power station is 0 ≤ k λ ≤5%, E act_q_2 The value is 1, otherwise E act_q_2 The value is 0; If any of the above operating conditions fail to meet the criteria, the new energy power station is deemed not to have the adaptability for transient reactive power active support; the transient reactive power active support type sub-index E is obtained according to formula (22). act_q value; （22） In the formula, To analyze the transient reactive power active support type sub-index E act_q Operating condition number, To analyze the transient reactive power active support type sub-index E act_q The number of working conditions.

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