A wind farm high voltage ride-through capability simulation test method and device

Abstract

This invention relates to a simulation testing method and apparatus for the high-voltage ride-through capability of wind farms, comprising: adjusting the three-phase symmetrical fault voltage or the two-phase asymmetrical fault voltage at the wind farm grid connection point in a wind farm simulation system to simulate fault scenarios at the wind farm grid connection point; acquiring electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point in each fault scenario; and determining the high-voltage ride-through capability of the wind farm in each fault scenario based on the electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point. The high-voltage ride-through capability simulation testing method and apparatus provided by this invention offers an effective technical means to determine whether a wind farm possesses high-voltage ride-through capability, ensuring the grid operation safety after large-scale wind power integration into the DC near-area system and improving the wind power transmission capacity of the UHVDC system.

Description

Technical Field

[0001] This invention relates to the field of power system simulation and verification, specifically to a simulation test method and apparatus for the high voltage ride-through capability of wind farms. Background Technology

[0002] During power transmission, ultra-high voltage direct current (UHVDC) systems frequently experience faults such as commutation failure and DC blocking. These faults cause a drop in system voltage and a surge in current, reducing the reactive power consumed by the converter station. This results in a large influx of surplus reactive current into the AC system, causing a sharp rise in AC voltage. When the overvoltage amplitude exceeds the protection threshold of near-field wind turbines in the DC system, it can trigger a large-scale wind turbine disconnection accident, leading to system instability. To avoid the cascading disconnection of numerous wind turbines caused by transient overvoltages resulting from DC commutation failures and DC blocking, near-field wind turbines / wind farms in the DC system must possess high-voltage ride-through capability.

[0003] The standard GB / T 36995-2018 "Test Procedure for Fault Voltage Ride-through Capability of Wind Turbine Generators" and the energy industry standard NB / T 31111-2017 "Test Procedure for High Voltage Ride-through Capability of Wind Turbine Generators" have been released and implemented. At present, whether a wind turbine generator has high voltage ride-through capability can be verified by on-site testing. However, the presence of high voltage ride-through capability in a wind turbine generator does not necessarily indicate that the wind farm has high voltage ride-through capability. Therefore, it is urgent to study the testing method for the high voltage ride-through capability of wind farms. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a simulation test method and apparatus for the high voltage ride-through capability of wind farms. This provides an effective technical means to determine whether a wind farm has high voltage ride-through capability, ensuring the safe operation of the power grid after large-scale wind power is connected to the DC near-area system, and improving the wind power transmission capacity of the UHVDC system.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] This invention provides a simulation test method for the high voltage ride-through capability of wind farms, the improvement of which is that the method includes:

[0007] Step 1: Adjust the three-phase symmetrical fault voltage or two-phase asymmetrical fault voltage at the wind farm grid connection point in the wind farm simulation system to simulate the fault scenario at the wind farm grid connection point.

[0008] Step 2: Obtain the electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point in each fault scenario;

[0009] Step 3: Determine the high voltage ride-through capability of the wind farm in each fault scenario of the wind turbine terminal bus and the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point.

[0010] Preferably, step 1 includes:

[0011] In the wind farm simulation system, the output of the wind turbine is set to its rated output, the wind turbine operates at unity power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm is zero. The three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is increased to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Alternatively, the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is increased to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively.

[0012] In the wind farm simulation system, the output of the wind turbine is set to its rated output, the wind turbine operates at its maximum leading power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm is set to its maximum capacitive reactive power output. The three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Alternatively, the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively.

[0013] In the wind farm simulation system, the output of the wind turbine is set to its rated output, the wind turbine operates at its maximum lagging power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm is set to the maximum inductive reactive power output. The three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Alternatively, the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively.

[0014] Preferably, the electrical data of the wind turbine terminal bus includes the terminal bus voltage, active power, reactive power, reactive current and their corresponding simulated waveforms for all wind turbines;

[0015] The electrical data of the wind farm grid connection point includes the voltage, active power, reactive power, reactive current and their corresponding simulated waveforms at the wind farm grid connection point.

[0016] Furthermore, step 3 includes:

[0017] Step 3-1: Determine the test data for each fault scenario of the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point in each fault scenario.

[0018] Step 3-2: Detect the high voltage ride-through capability of the wind farm in various fault scenarios at the wind farm grid connection point based on the test data of each fault scenario at the wind farm grid connection point.

[0019] The test data includes: the grid-connected operation status of all wind turbines in the wind farm, the active power recovery time of the wind farm, the response time of dynamic inductive reactive current injection in the wind farm, the adjustment time of dynamic inductive reactive current injection in the wind farm, and the average value of dynamic inductive reactive current injection in the wind farm.

[0020] Furthermore, step 3-1 includes:

[0021] If the terminal bus voltage of all wind turbines in the i-th fault scenario at the wind farm grid connection point is lower than the overvoltage protection setting value, then the grid-connected operation status of all wind turbines in the wind farm in the i-th fault scenario at the wind farm grid connection point is grid-connected operation; otherwise, the grid-connected operation status of all wind turbines in the wind farm in the i-th fault scenario at the wind farm grid connection point is grid-off operation.

[0022] The active power recovery time t of the wind farm in the i-th fault scenario at the grid connection point is determined by the following formula. reci :

[0023] t reci =t a2i -t a1i ;

[0024] The response time t of the dynamic inductive reactive current injection of the wind farm in the i-th fault scenario at the grid connection point of the wind farm is determined by the following formula. resi ;

[0025] t resi =t r1i -t 0i ;

[0026] The dynamic inductive reactive current injection adjustment time t of the wind farm in the i-th fault scenario at the wind farm grid connection point is determined by the following formula. tsi ;

[0027] t tsi =t r2i -t 0i ;

[0028] The average value of dynamic inductive reactive current injection I in the i-th fault scenario at the wind farm grid connection point is determined by the following formula. qi ;

[0029]

[0030] In the formula, i∈[1,N], N is the total number of fault scenarios at the grid connection point of the wind farm, and t a1i Let t be the fault clearing time in the i-th fault scenario at the wind farm's grid connection point. a2i Let t be the starting point when the active power of the wind farm continuously exceeds 90% P0 in the i-th fault scenario at the wind farm's grid connection point, where P0 is the active power at the wind farm's grid connection point before the fault. 0i Let t be the starting moment when the voltage at the wind farm's grid connection point rises to 110% of the rated voltage in the i-th fault scenario at the wind farm's grid connection point. r1i For the first time, during the voltage rise period of the i-th fault scenario at the wind farm grid connection point, the reactive current injection of the wind farm reaches I. Q2 At that moment, I Q2 To inject 90% of the steady-state current value into the dynamic reactive current of the wind farm, t r2i Let t be the starting time when the reactive current of the wind farm enters and remains within the allowable error band of the steady-state value during the voltage rise period in the i-th fault scenario at the wind farm's grid connection point. r3i The allowable error x is the end time when the reactive current of the wind farm enters and remains within the allowable error band during the voltage rise at the grid connection point of the wind farm in the i-th fault scenario. The allowable error x is ±5%|ΔI Q |,ΔI Q =I Q1 -I Q0 , I qi (t) represents the reactive current of the wind farm at time t in the i-th fault scenario at the wind farm's grid connection point. Q0 I represents the reactive current value at the wind farm's grid connection point before the fault. Q1 ΔI is the steady-state value of the dynamic reactive current injection into the wind farm during a fault. Q This is the difference between the steady-state value of the dynamic reactive current injection into the wind farm during the fault and the reactive current value at the wind farm's grid connection point before the fault.

[0031] Furthermore, step 3-2 includes:

[0032] If, in each fault scenario at the wind farm's grid connection point, all wind turbines within the wind farm can maintain grid-connected operation, the active power recovery time of the wind farm does not exceed 100ms, the response time of the wind farm's dynamic inductive reactive current injection does not exceed 50ms, the adjustment time of the wind farm's dynamic inductive reactive current injection does not exceed 150ms, the average value of the wind farm's dynamic inductive reactive current injection is within the limit range of the wind farm's dynamic inductive reactive current injection value, and the wind farm can continuously inject dynamic inductive reactive current during the fault period, then the wind farm is determined to have high voltage ride-through capability in each fault scenario at the wind farm's grid connection point; otherwise, the wind farm does not have high voltage ride-through capability in each fault scenario at the wind farm's grid connection point.

[0033] Among them, the limit range I of the dynamic inductive reactive current injection value of the wind farm required by the standard is determined by the following formula. TL :

[0034] I TL =K×(U T -1.1)I n , (1.1≤U T ≤1.3);

[0035] In the formula, K is the dynamic inductive reactive current proportionality coefficient of the wind farm, and K takes a value of 1 to 2. T I is the per-unit value of the voltage rise at the grid connection point of the wind farm. n This is the rated current value of the wind farm.

[0036] The present invention also provides a simulation test device for high voltage ride-through capability of wind farms, wherein the improvement is that the device comprises:

[0037] The simulation module is used to adjust the three-phase symmetrical fault voltage or two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system to simulate the fault scenarios at the grid connection point of the wind farm.

[0038] The acquisition module is used to acquire electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point in various fault scenarios.

[0039] The determination module is used to determine the high voltage ride-through capability of the wind farm in each fault scenario of the wind turbine terminal bus and the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point in each fault scenario of the wind farm grid connection point.

[0040] Compared with the closest existing technology, the present invention has the following advantages:

[0041] This invention provides a simulation test method and apparatus for high-voltage ride-through capability of wind farms, eliminating many irrelevant simulation conditions, greatly reducing the simulation workload, improving simulation efficiency, and facilitating the engineering application of high-voltage ride-through capability evaluation for wind farms. Furthermore, the simulation test method and apparatus for high-voltage ride-through capability of wind farms provided by this invention can evaluate and monitor the high-voltage ride-through capability of operating and planned wind farms, providing an effective technical means to determine whether a wind farm possesses high-voltage ride-through capability. This can ensure the safe operation of the power grid after large-scale wind power is integrated into the DC near-area system and improve the wind power transmission capacity of the UHVDC system. Attached Figure Description

[0042] Figure 1 A flowchart of a simulation test method for high voltage ride-through capability of wind farms provided by the present invention;

[0043] Figure 2 A detailed electrical model diagram of a wind farm is provided by the present invention.

[0044] Figure 3 A schematic diagram of a wind farm high voltage ride-through capability simulation test device provided by the present invention. Detailed Implementation

[0045] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] This invention provides a simulation test method for the high voltage ride-through capability of wind farms, such as... Figure 1 As shown, the method includes:

[0048] Step 1: Adjust the three-phase symmetrical fault voltage or two-phase asymmetrical fault voltage at the wind farm grid connection point in the wind farm simulation system to simulate the fault scenario at the wind farm grid connection point.

[0049] Step 2: Obtain the electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point in each fault scenario;

[0050] Step 3: Determine the high voltage ride-through capability of the wind farm in each fault scenario of the wind turbine terminal bus and the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point.

[0051] The electrical data of the wind turbine terminal bus includes the voltage, active power, reactive power, reactive current and corresponding simulated waveforms of all wind turbine terminal bus data; the electrical data of the wind farm grid connection point includes the voltage, active power, reactive power, reactive current and corresponding simulated waveforms of the wind farm grid connection point.

[0052] Specifically, step 1 includes:

[0053] In the wind farm simulation system, the output of the wind turbine is set to its rated output, the wind turbine operates at unity power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm is zero. The three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is increased to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Alternatively, the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is increased to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively.

[0054] In the wind farm simulation system, the output of the wind turbine is set to its rated output, the wind turbine operates at its maximum leading power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm is set to its maximum capacitive reactive power output. The three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Alternatively, the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively.

[0055] In the wind farm simulation system, the output of the wind turbine is set to its rated output, the wind turbine operates at its maximum lagging power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm is set to the maximum inductive reactive power output. The three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Alternatively, the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively.

[0056] For example, taking the detailed electrical model structure diagram of a wind farm provided by this invention as an example, such as... Figure 2 As shown, a detailed electrical model of the wind farm is established based on the validated wind turbine model and dynamic inductive reactive power compensation device model.

[0057] After simulating fault scenarios at the wind farm grid connection point by adjusting the three-phase symmetrical fault voltage or two-phase asymmetrical fault voltage at the wind farm grid connection point in the wind farm simulation system, it is necessary to obtain the electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point in each fault scenario. Then, based on the electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point in each fault scenario, the high-voltage ride-through capability of the wind farm in each fault scenario at the wind farm grid connection point is determined. Therefore, step 3 includes:

[0058] Step 3-1: Determine the test data for each fault scenario of the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point in each fault scenario.

[0059] Step 3-2: Detect the high voltage ride-through capability of the wind farm in various fault scenarios at the wind farm grid connection point based on the test data of each fault scenario at the wind farm grid connection point.

[0060] The test data includes: the grid-connected operation status of all wind turbines in the wind farm, the active power recovery time of the wind farm, the response time of dynamic inductive reactive current injection in the wind farm, the adjustment time of dynamic inductive reactive current injection in the wind farm, and the average value of dynamic inductive reactive current injection in the wind farm.

[0061] Specifically, step 3-1 includes:

[0062] Step 3-1-1: Based on the bus voltage at the turbine terminals of the wind turbines and their corresponding simulation waveforms in the i-th fault scenario at the wind farm's grid connection point, determine the grid-connected operation status of all wind turbines in the i-th fault scenario at the wind farm's grid connection point:

[0063] If the terminal bus voltage of all wind turbines in the i-th fault scenario at the wind farm grid connection point is lower than the overvoltage protection setting value, then the grid-connected operation status of all wind turbines in the wind farm in the i-th fault scenario at the wind farm grid connection point is grid-connected operation; otherwise, the grid-connected operation status of all wind turbines in the wind farm in the i-th fault scenario at the wind farm grid connection point is grid-off operation.

[0064] Step 3-1-2: Determine the active power recovery time t of the wind farm in the i-th fault scenario at the wind farm grid connection point according to the following formula. reci :

[0065] t reci =t a2i -t a1i ;

[0066] Step 3-1-3: Determine the dynamic inductive reactive current injection response time t of the wind farm in the i-th fault scenario at the wind farm grid connection point according to the following formula. resi ;

[0067] t resi =t r1i -t 0i ;

[0068] Step 3-1-4: Determine the dynamic inductive reactive current injection adjustment time t of the wind farm in the i-th fault scenario at the wind farm grid connection point according to the following formula. tsi ;

[0069] t tsi =t r2i -t 0i ;

[0070] Step 3-1-5: Determine the average value I of the dynamic inductive reactive current injection of the wind farm in the i-th fault scenario at the wind farm grid connection point according to the following formula. qi ;

[0071]

[0072] In the above formula, i∈[1,N], N is the total number of fault scenarios at the wind farm grid connection point, and t a1i Let t be the fault clearing time in the i-th fault scenario at the wind farm's grid connection point. a2i Let t be the starting point when the active power of the wind farm continuously exceeds 90% P0 in the i-th fault scenario at the wind farm's grid connection point, where P0 is the active power at the wind farm's grid connection point before the fault. 0i Let t be the starting moment when the voltage at the wind farm's grid connection point rises to 110% of the rated voltage in the i-th fault scenario at the wind farm's grid connection point. r1i For the first time, during the voltage rise period of the i-th fault scenario at the wind farm grid connection point, the reactive current injection of the wind farm reaches I. Q2 At that moment, I Q2 To inject 90% of the steady-state current value into the dynamic reactive current of the wind farm, t r2i Let t be the starting time when the reactive current of the wind farm enters and remains within the allowable error band of the steady-state value during the voltage rise period in the i-th fault scenario at the wind farm's grid connection point. r3i The allowable error x is the end time when the reactive current of the wind farm enters and remains within the allowable error band during the voltage rise at the grid connection point of the wind farm in the i-th fault scenario. The allowable error x is ±5%|ΔI Q |,ΔI Q =I Q1 -I Q0 , I q i (t) represents the reactive current of the wind farm at time t in the i-th fault scenario at the wind farm's grid connection point. Q0 I represents the reactive current value at the wind farm's grid connection point before the fault. Q1ΔI is the steady-state value of the dynamic reactive current injection into the wind farm during a fault. Q This is the difference between the steady-state value of the dynamic reactive current injection into the wind farm during the fault and the reactive current value at the wind farm's grid connection point before the fault.

[0073] Specifically, step 3-2 includes:

[0074] If, in each fault scenario at the wind farm's grid connection point, all wind turbines within the wind farm can maintain grid-connected operation, the active power recovery time of the wind farm does not exceed 100ms, the response time of the wind farm's dynamic inductive reactive current injection does not exceed 50ms, the adjustment time of the wind farm's dynamic inductive reactive current injection does not exceed 150ms, the average value of the wind farm's dynamic inductive reactive current injection is within the limit range of the wind farm's dynamic inductive reactive current injection value, and the wind farm can continuously inject dynamic inductive reactive current during the fault period, then the wind farm is determined to have high voltage ride-through capability in each fault scenario at the wind farm's grid connection point; otherwise, the wind farm does not have high voltage ride-through capability in each fault scenario at the wind farm's grid connection point.

[0075] Among them, the limit range I of the dynamic inductive reactive current injection value of the wind farm required by the standard is determined by the following formula. TL :

[0076] I TL =K×(U T -1.1)I n , (1.1≤U T ≤1.3);

[0077] In the formula, K is the dynamic inductive reactive current proportionality coefficient of the wind farm, and K takes a value of 1 to 2. T I is the per-unit value of the voltage rise at the grid connection point of the wind farm. n This is the rated current value of the wind farm.

[0078] Based on the same concept as the above control method, the present invention also provides a simulation test device for the high voltage ride-through capability of wind farms, such as... Figure 3 As shown, the device includes:

[0079] The simulation module is used to adjust the three-phase symmetrical fault voltage or two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system to simulate the fault scenarios at the grid connection point of the wind farm.

[0080] The acquisition module is used to acquire electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point in various fault scenarios.

[0081] The determination module is used to determine the high voltage ride-through capability of the wind farm in each fault scenario of the wind turbine terminal bus and the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point in each fault scenario of the wind farm grid connection point.

[0082] Preferably, the simulation module includes:

[0083] The first regulating unit is used to set the output of the wind turbine generator in the wind farm simulation system to its rated output, the wind turbine generator to operate at a unity power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm to zero. It also regulates the three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, or the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively.

[0084] The second adjustment unit is used to set the output of the wind turbine in the wind farm simulation system to its rated output, the wind turbine to operate at the maximum leading power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm to the maximum capacitive reactive power output. It adjusts the three-phase symmetrical fault voltage of the wind farm grid connection point in the wind farm simulation system to 120%, 125%, or 130% of the rated voltage of the wind farm grid connection point, respectively, or the two-phase asymmetrical fault voltage of the wind farm grid connection point in the wind farm simulation system to 120%, 125%, or 130% of the rated voltage of the wind farm grid connection point, respectively.

[0085] The third adjustment unit is used to set the output of the wind turbine in the wind farm simulation system to its rated output, the wind turbine to operate at the maximum lagging power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm to the maximum inductive reactive power output. It adjusts the three-phase symmetrical fault voltage of the wind farm grid connection point in the wind farm simulation system to 120%, 125%, or 130% of the rated voltage of the wind farm grid connection point, respectively, or the two-phase asymmetrical fault voltage of the wind farm grid connection point in the wind farm simulation system to 120%, 125%, or 130% of the rated voltage of the wind farm grid connection point, respectively.

[0086] The electrical data of the wind turbine terminal bus includes the voltage, active power, reactive power, reactive current and corresponding simulated waveforms of all wind turbine terminal bus data; the electrical data of the wind farm grid connection point includes the voltage, active power, reactive power, reactive current and corresponding simulated waveforms of the wind farm grid connection point.

[0087] Furthermore, the determining module includes:

[0088] The first determining unit is used to determine the test data of each fault scenario of the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point in each fault scenario of the wind farm grid connection point.

[0089] The second determining unit is used to detect the high voltage ride-through capability of the wind farm in each fault scenario at the wind farm grid connection point based on the test data of each fault scenario at the wind farm grid connection point.

[0090] The test data includes: the grid-connected operation status of all wind turbines in the wind farm, the active power recovery time of the wind farm, the response time of dynamic inductive reactive current injection in the wind farm, the adjustment time of dynamic inductive reactive current injection in the wind farm, and the average value of dynamic inductive reactive current injection in the wind farm.

[0091] Furthermore, the first determining unit includes:

[0092] The first determining subunit is used to determine the grid-connected operation status of all wind turbine units in the wind farm in the first fault scenario of the wind farm grid connection point if the terminal bus voltage of all wind turbine units in the wind farm is lower than the overvoltage protection setting value; otherwise, the grid-connected operation status of all wind turbine units in the wind farm in the first fault scenario of the wind farm grid connection point is disconnected from the grid.

[0093] The second determining subunit is used to determine the active power recovery time t of the wind farm in the i-th fault scenario at the wind farm grid connection point according to the following formula. reci :

[0094] t reci =t a2i -t a1i ;

[0095] The third determining subunit is used to determine the dynamic inductive reactive current injection response time t of the wind farm in the i-th fault scenario at the wind farm grid connection point according to the following formula. resi ;

[0096] t resi =t r1i -t 0i ;

[0097] The fourth determining subunit is used to determine the dynamic inductive reactive current injection adjustment time t of the wind farm in the i-th fault scenario at the wind farm grid connection point according to the following formula. tsi ;

[0098] t tsi =t r2i -t 0i ;

[0099] The fifth determining subunit is used to determine the average value I of the dynamic inductive reactive current injection of the wind farm in the i-th fault scenario at the wind farm grid connection point according to the following formula. qi ;

[0100]

[0101] In the formula, i∈[1,N], N is the total number of fault scenarios at the grid connection point of the wind farm, and t a1i Let t be the fault clearing time in the i-th fault scenario at the wind farm's grid connection point. a2i Let t be the starting point when the active power of the wind farm continuously exceeds 90% P0 in the i-th fault scenario at the wind farm's grid connection point, where P0 is the active power at the wind farm's grid connection point before the fault. 0i Let t be the starting moment when the voltage at the wind farm's grid connection point rises to 110% of the rated voltage in the i-th fault scenario at the wind farm's grid connection point. r1i For the first time, during the voltage rise period of the i-th fault scenario at the wind farm grid connection point, the reactive current injection of the wind farm reaches I. Q2 At that moment, I Q2 To inject 90% of the steady-state current value into the dynamic reactive current of the wind farm, t r2i Let t be the starting time when the reactive current of the wind farm enters and remains within the allowable error band of the steady-state value during the voltage rise period in the i-th fault scenario at the wind farm's grid connection point. r3i The allowable error x is the end time when the reactive current of the wind farm enters and remains within the allowable error band during the voltage rise at the grid connection point of the wind farm in the i-th fault scenario. The allowable error x is ±5%|ΔI Q |,ΔI Q =I Q1 -I Q0 , I qi (t) represents the reactive current of the wind farm at time t in the i-th fault scenario at the wind farm's grid connection point. Q0 I represents the reactive current value at the wind farm's grid connection point before the fault. Q1 ΔI is the steady-state value of the dynamic reactive current injection into the wind farm during a fault. Q This is the difference between the steady-state value of the dynamic reactive current injection into the wind farm during the fault and the reactive current value at the wind farm's grid connection point before the fault.

[0102] Furthermore, the second determining unit is used for:

[0103] If, in each fault scenario at the wind farm's grid connection point, all wind turbines within the wind farm can maintain grid-connected operation, the active power recovery time of the wind farm does not exceed 100ms, the response time of the wind farm's dynamic inductive reactive current injection does not exceed 50ms, the adjustment time of the wind farm's dynamic inductive reactive current injection does not exceed 150ms, the average value of the wind farm's dynamic inductive reactive current injection is within the limit range of the wind farm's dynamic inductive reactive current injection value, and the wind farm can continuously inject dynamic inductive reactive current during the fault period, then the wind farm is determined to have high voltage ride-through capability in each fault scenario at the wind farm's grid connection point; otherwise, the wind farm does not have high voltage ride-through capability in each fault scenario at the wind farm's grid connection point.

[0104] Among them, the limit range I of the dynamic inductive reactive current injection value of the wind farm required by the standard is determined by the following formula. TL :

[0105] I TL =K×(U T -1.1)I n , (1.1≤U T ≤1.3);

[0106] In the formula, K is the dynamic inductive reactive current proportionality coefficient of the wind farm, and K takes a value of 1 to 2. T I is the per-unit value of the voltage rise at the grid connection point of the wind farm. n This is the rated current value of the wind farm.

[0107] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0108] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0109] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0110] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0111] 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 protection of the claims of the present invention.

Claims

1. A simulation test method for the high voltage ride-through capability of wind farms, characterized in that, The method includes: Step 1: Adjust the three-phase symmetrical fault voltage or two-phase asymmetrical fault voltage at the wind farm grid connection point in the wind farm simulation system to simulate the fault scenario at the wind farm grid connection point. Step 2: Obtain the electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point in each fault scenario; Step 3: Determine the high voltage ride-through capability of the wind farm in each fault scenario of the wind turbine terminal bus and the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point. Step 1 includes: In the wind farm simulation system, the output of the wind turbine is set to its rated output, the wind turbine operates at unity power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm is zero. The three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is increased to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Alternatively, the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is increased to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. In the wind farm simulation system, the output of the wind turbine is set to its rated output, the wind turbine operates at its maximum leading power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm is set to its maximum capacitive reactive power output. The three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Alternatively, the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. In the wind farm simulation system, the output of the wind turbine is set to its rated output, the wind turbine operates at the maximum lagging power factor, and the reactive power output of the reactive power compensation device corresponding to the wind farm is set to the maximum inductive reactive power output. The three-phase symmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Alternatively, the two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system is adjusted to 120%, 125%, or 130% of the rated voltage at the grid connection point of the wind farm, respectively. Step 3 includes: Step 3-1: Determine the test data for each fault scenario of the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point in each fault scenario. Step 3-2: Detect the high voltage ride-through capability of the wind farm in various fault scenarios at the wind farm grid connection point based on the test data of each fault scenario at the wind farm grid connection point. The test data includes: the grid-connected operation status of all wind turbines in the wind farm, the active power recovery time of the wind farm, the response time of dynamic inductive reactive current injection in the wind farm, the adjustment time of dynamic inductive reactive current injection in the wind farm, and the average value of dynamic inductive reactive current injection in the wind farm. Step 3-2 includes: If, in each fault scenario at the wind farm's grid connection point, all wind turbines within the wind farm can maintain grid-connected operation, the active power recovery time of the wind farm does not exceed 100ms, the response time of the wind farm's dynamic inductive reactive current injection does not exceed 50ms, the adjustment time of the wind farm's dynamic inductive reactive current injection does not exceed 150ms, the average value of the wind farm's dynamic inductive reactive current injection is within the limit range of the wind farm's dynamic inductive reactive current injection value, and the wind farm can continuously inject dynamic inductive reactive current during the fault period, then the wind farm is determined to have high voltage ride-through capability in each fault scenario at the wind farm's grid connection point; otherwise, the wind farm does not have high voltage ride-through capability in each fault scenario at the wind farm's grid connection point. Among them, the limit range I of the dynamic inductive reactive current injection value of the wind farm required by the standard is determined by the following formula. TL : I TL =K×(U T -1.1)I n ,(1.1≤U T ≤1.3); In the formula, K is the dynamic inductive reactive current proportionality coefficient of the wind farm, and K takes a value of 1 to 2. T I is the per-unit value of the voltage rise at the grid connection point of the wind farm. n This is the rated current value of the wind farm.

2. The method as described in claim 1, characterized in that, The electrical data of the wind turbine terminal bus includes the terminal bus voltage, active power, reactive power, reactive current and their corresponding simulation waveforms for all wind turbines. The electrical data of the wind farm grid connection point includes the voltage, active power, reactive power, reactive current and their corresponding simulated waveforms at the wind farm grid connection point.

3. The method as described in claim 1, characterized in that, Step 3-1 includes: If the terminal bus voltage of all wind turbines in the i-th fault scenario at the wind farm grid connection point is lower than the overvoltage protection setting value, then the grid-connected operation status of all wind turbines in the wind farm in the i-th fault scenario at the wind farm grid connection point is grid-connected operation; otherwise, the grid-connected operation status of all wind turbines in the wind farm in the i-th fault scenario at the wind farm grid connection point is grid-off operation. The active power recovery time t of the wind farm in the i-th fault scenario at the grid connection point is determined by the following formula. reci : t reci =t a2i -t a1i ; The response time t of the dynamic inductive reactive current injection of the wind farm in the i-th fault scenario at the grid connection point of the wind farm is determined by the following formula. resi ; t resi =t r1i -t 0i ; The dynamic inductive reactive current injection adjustment time t of the wind farm in the i-th fault scenario at the wind farm grid connection point is determined by the following formula. tsi ; t tsi =t r2i -t 0i ; The average value of dynamic inductive reactive current injection I in the i-th fault scenario at the wind farm grid connection point is determined by the following formula. qi ; In the formula, i∈[1,N], N is the total number of fault scenarios at the grid connection point of the wind farm, and t a1i Let t be the fault clearing time in the i-th fault scenario at the wind farm's grid connection point. a2i Let t be the starting point when the active power of the wind farm continuously exceeds 90% P0 in the i-th fault scenario at the wind farm's grid connection point, where P0 is the active power at the wind farm's grid connection point before the fault. 0i Let t be the starting moment when the voltage at the wind farm's grid connection point rises to 110% of the rated voltage in the i-th fault scenario at the wind farm's grid connection point. r1i For the first time, during the voltage rise period of the i-th fault scenario at the wind farm grid connection point, the reactive current injection of the wind farm reaches I. Q2 At that moment, I Q2 To inject 90% of the steady-state current value into the dynamic reactive current of the wind farm, t r2i Let t be the starting time when the reactive current of the wind farm enters and remains within the allowable error band of the steady-state value during the voltage rise period in the i-th fault scenario at the wind farm's grid connection point. r3i The allowable error x is the end time when the reactive current of the wind farm enters and remains within the allowable error band during the voltage rise at the grid connection point of the wind farm in the i-th fault scenario. The allowable error x is ±5%|ΔI Q |,ΔI Q =I Q1 -I Q0 , I qi (t) represents the reactive current of the wind farm at time t in the i-th fault scenario at the wind farm's grid connection point. Q0 I represents the reactive current value at the wind farm's grid connection point before the fault. Q1 ΔI is the steady-state value of the dynamic reactive current injection into the wind farm during a fault. Q This is the difference between the steady-state value of the dynamic reactive current injection into the wind farm during the fault and the reactive current value at the wind farm's grid connection point before the fault.

4. A simulation testing device suitable for the high-voltage ride-through capability simulation testing method of wind farms as described in claim 1, characterized in that, The device includes: The simulation module is used to adjust the three-phase symmetrical fault voltage or two-phase asymmetrical fault voltage at the grid connection point of the wind farm in the wind farm simulation system to simulate the fault scenarios at the grid connection point of the wind farm. The acquisition module is used to acquire electrical data of the wind turbine terminal busbars and the electrical data of the wind farm grid connection point in various fault scenarios. The determination module is used to determine the high voltage ride-through capability of the wind farm in each fault scenario of the wind turbine terminal bus and the wind farm grid connection point based on the electrical data of the wind turbine terminal bus and the electrical data of the wind farm grid connection point in each fault scenario of the wind farm grid connection point.

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