Method and system for testing multi-feature fault ride-through capability of wind turbine generator

Abstract

The invention provides a multi-feature fault ride-through capability test method and system for a wind turbine generator. The method comprises the following steps: determining a fault ride-through test type according to test content; according to a setting requirement corresponding to the fault ride-through test type, calculating a regulation quantity of parameters related to the setting requirement; testing the voltage fault ride-through capability of the wind turbine generator based on the regulation and control quantity and a fault voltage generation system simulation test working condition; wherein the fault voltage generation system is a fault voltage generation system adopting low short circuit ratio simulation, and the fault voltage generation system simulates a test working condition by controlling the access of short circuit impedance and boost impedance. The control quantity of the related parameters is determined according to the fault ride-through test type, the voltage fault ride-through capability of the wind turbine generator is tested based on the test working condition simulated by the fault voltage generation system, and safe and stable operation of a new energy power system is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of new energy access and control, and in particular to a method and system for testing the multi-feature fault ride-through capability of a wind turbine generator set. Background Art

[0002] Renewable energy represented by wind power and photovoltaic power is connected to the grid through power electronic converters. It is very easy to trip off the grid when the power system is disturbed or faulty. In recent years, with the promotion and application of fault ride-through control technology and testing technology, the problem of fault tripping of new energy in strong or relatively strong power grids has been solved to a large extent, ensuring the safe operation of the system. However, with the continuous increase in the proportion of new energy access, the short-circuit ratio of the power system has decreased, the regulation capacity has significantly decreased, and the risk of voltage faults has increased. Compared with the strong power grid environment, the stable operation level of wind turbines in the low short-circuit ratio of the power grid is low, the disturbance is frequent, and the transient characteristics of wind turbines are worse when the system voltage fails. Therefore, it is urgent to standardize the transient behavior of wind turbines under the low short-circuit ratio of the system, test and verify their fault ride-through capabilities, and ensure the safe and stable operation of the current and future higher proportion of new energy power systems. The existing technologies do not involve the fault ride-through test methods and steps of wind turbines with low short-circuit ratios, and do not consider the comprehensive impact of the output power of wind turbines on the terminal voltage and network loss level under low short-circuit ratios. Summary of the invention

[0003] In order to solve the problem that the prior art does not involve a wind turbine fault ride-through test method and steps with a low short-circuit ratio, and does not consider the comprehensive influence of the wind turbine output power on the terminal voltage and network loss level under a low short-circuit ratio, the present invention proposes a fault voltage generation system for low short-circuit ratio simulation, including: system impedance, flow limiting impedance, short-circuit impedance, boost impedance, a first bypass switch, a second bypass switch, a first short-circuit switch, and a second short-circuit switch;

[0004] The system impedance is connected in parallel with the first bypass switch;

[0005] The current limiting resistor is connected in parallel with the second bypass switch;

[0006] The short-circuit impedance is connected in series with the first short-circuit switch to form a first branch;

[0007] The boost impedance and the second short-circuit switch are connected in series to form a second branch;

[0008] One end of the system impedance is connected to the power grid, and the other end is connected to one end of the flow-limiting resistor, and the other end of the flow-limiting resistor is connected to the wind turbine;

[0009] The first branch and the second branch are connected in parallel and then connected between the flow-limiting reactor and the wind turbine generator set.

[0010] Optionally, the system impedance includes: a resistance and an inductance connected in series;

[0011] One end of the resistor is connected to the power grid, and the other end is connected to one end of the inductive reactance, and the other end of the inductive reactance is connected to the current limiting reactance.

[0012] In another aspect, the present invention further discloses a method for testing the multi-feature fault ride-through capability of a wind turbine generator set, comprising:

[0013] Determine the fault ride-through test type based on the test content;

[0014] Calculate the control amount of the parameters related to the setting requirements according to the setting requirements corresponding to the fault ride-through test type;

[0015] Based on the control quantity and the fault voltage generation system simulation test condition, the voltage fault ride-through capability of the wind turbine is tested;

[0016] Wherein, the fault voltage generating system is a fault voltage generating system using the low short-circuit ratio simulation described above.

[0017] Optionally, determining the fault ride-through test type according to the test content includes:

[0018] When the test content is a low voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a low voltage ride-through test type;

[0019] When the test content is a high voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a high voltage ride-through test type;

[0020] When the test content is a low-high voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a low-high voltage ride-through test type;

[0021] When the test content is a high-low voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a high-low voltage ride-through test type.

[0022] Optionally, the step of calculating the control amount of the parameter according to the setting requirement corresponding to the fault ride-through test type includes:

[0023] When the fault ride-through test type is a low voltage ride-through test type, the current limiting impedance adjustment amount and the short-circuit impedance adjustment amount are calculated respectively according to the short-circuit ratio setting requirement and the voltage setting requirement of the low voltage ride-through test type;

[0024] When the fault ride-through test type is a high voltage ride-through test type, the flow limiting impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the short circuit ratio setting requirement and the voltage setting requirement of the high voltage ride-through test type;

[0025] When the fault ride-through test type is a low-high voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirement of the low-high voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the voltage drop and rise values;

[0026] When the fault ride-through test type is a high-low voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirements of the high-low voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance value adjustment amount are calculated respectively according to the voltage rise and drop values.

[0027] Optionally, the flow-limiting resistance regulating amount is calculated according to the following formula:

[0028]

[0029] Where, X sr is the limiting resistance adjustment, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively, R V is the resistance, X V For inductive resistance.

[0030] Optionally, the short-circuit impedance adjustment amount is calculated as follows:

[0031]

[0032] In the formula, Z sc is the short-circuit impedance adjustment value, U set is the voltage setting value, U N is the rated voltage of the wind turbine, X sr To limit the amount of influenza resistance regulation, X V is the inductive reactance, R V For resistance.

[0033] Optionally, the boost impedance adjustment amount is calculated as follows:

[0034]

[0035] In the formula, Z c is the boost impedance adjustment value.

[0036] Optionally, the voltage fault ride-through capability of the wind turbine generator set is tested based on the control variable and the fault voltage generation system simulation test condition, including:

[0037] The low voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to generate low voltage working conditions under low short circuit ratio;

[0038] The high voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to generate high voltage working conditions under low short circuit ratio;

[0039] The low-high voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to generate low-high voltage working conditions under low short-circuit ratio;

[0040] The high-low voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to produce high-low voltage conditions under low short-circuit ratio.

[0041] Optionally, the method of generating a low voltage condition under a low short-circuit ratio by combining a fault voltage generation system with a control amount to test the low voltage fault ride-through capability of the wind turbine generator system includes:

[0042] The current limiting impedance and the short-circuit impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The first short-circuit switch is closed to put the system impedance, the current limiting impedance and the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the low voltage condition under low short circuit and test the low voltage fault ride-through capability of the wind turbine.

[0043] Optionally, the method of generating a high voltage condition under a low short-circuit ratio by combining a fault voltage generation system with a control amount to test the high voltage fault ride-through capability of the wind turbine generator system includes:

[0044] The current limiting impedance and the boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the second short-circuit switch is closed, and the system impedance, the current limiting impedance and the boost impedance are put into operation, and a voltage increase is generated at the test point to simulate the high voltage condition under low short circuit and test the high voltage fault ride-through capability of the wind turbine.

[0045] Optionally, the method of generating a low-high voltage working condition under a low short-circuit ratio by combining a fault voltage generation system with a control amount to test the low-high voltage fault ride-through capability of the wind turbine generator includes:

[0046] The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the first short-circuit switch is closed, and the system impedance, the current limiting impedance and the short-circuit impedance are put into operation, and a voltage drop is generated at the test point. After a set time period, the first short-circuit switch is disconnected to take the short-circuit impedance out of operation, and the second short-circuit switch is closed to put the boost impedance into operation, and a voltage increase is generated at the test point to simulate the low-high voltage condition under low short circuit, and test the low-high voltage fault ride-through capability of the wind turbine.

[0047] Optionally, the method of generating a high-low voltage condition under a low short-circuit ratio by combining a fault voltage generation system with a control amount to test the high-low voltage fault ride-through capability of the wind turbine generator includes:

[0048] The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The second short-circuit switch is closed to put the system impedance, the current limiting impedance and the boost impedance into operation, and a voltage increase is generated at the test point. After a set time interval, the second short-circuit switch is disconnected to stop the short-circuit impedance from operating. The first short-circuit switch is closed to put the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the high-low voltage condition under low short circuit and test the high-low voltage fault ride-through capability of the wind turbine.

[0049] In another aspect, the present invention further provides a multi-feature fault ride-through capability test system for a wind turbine generator set, comprising:

[0050] A test type determination module, used to determine the fault ride-through test type according to the test content;

[0051] A control quantity calculation module, used to calculate the control quantity of parameters related to the setting requirements according to the setting requirements corresponding to the fault ride-through test type;

[0052] A simulation test module, used to test the voltage fault ride-through capability of the wind turbine generator set based on the control quantity and the fault voltage generation system simulation test condition;

[0053] Wherein, the fault voltage generating system is a fault voltage generating system using a low short circuit ratio simulation as described above.

[0054] Optionally, the test type determination module is specifically used to:

[0055] When the test content is a low voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a low voltage ride-through test type;

[0056] When the test content is a high voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a high voltage ride-through test type;

[0057] When the test content is a low-high voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a low-high voltage ride-through test type;

[0058] When the test content is a high-low voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a high-low voltage ride-through test type.

[0059] Optionally, the control amount calculation module is specifically used for:

[0060] When the fault ride-through test type is a low voltage ride-through test type, the current limiting impedance adjustment amount and the short-circuit impedance adjustment amount are calculated respectively according to the short-circuit ratio setting requirement and the voltage setting requirement of the low voltage ride-through test type;

[0061] When the fault ride-through test type is a high voltage ride-through test type, the flow limiting impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the short circuit ratio setting requirement and the voltage setting requirement of the high voltage ride-through test type;

[0062] When the fault ride-through test type is a low-high voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirement of the low-high voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the voltage drop and rise values;

[0063] When the fault ride-through test type is a high-low voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirements of the high-low voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance value adjustment amount are calculated respectively according to the voltage rise and drop values.

[0064] Optionally, the flow-limiting resistance regulating amount is calculated according to the following formula:

[0065]

[0066] In the formula, X sr is the limiting resistance adjustment, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively, R V is the resistance, X V For inductive resistance.

[0067] Optionally, the short-circuit impedance adjustment amount is calculated as follows:

[0068]

[0069] In the formula, Z sc is the short-circuit impedance adjustment value, U set is the voltage setting value, U N is the rated voltage of the wind turbine, X sr To limit the amount of influenza resistance regulation, X V is the inductive reactance, R V For resistance.

[0070] Optionally, the boost impedance adjustment amount is calculated as follows:

[0071]

[0072] In the formula, Z c is the boost impedance adjustment value.

[0073] Optionally, the simulation test module includes:

[0074] The low voltage ride-through submodule is used to generate a low voltage condition with a low short-circuit ratio by combining the fault voltage generation system with the control quantity to test the low voltage fault ride-through capability of the wind turbine;

[0075] The high voltage ride-through submodule is used to generate a high voltage condition with a low short-circuit ratio by combining the fault voltage generation system with the control quantity to test the high voltage fault ride-through capability of the wind turbine;

[0076] The low-high voltage ride-through submodule is used to generate low-high voltage working conditions under low short-circuit ratio by combining the fault voltage generation system with the control quantity to test the low-high voltage fault ride-through capability of the wind turbine;

[0077] The high-low voltage ride-through submodule is used to generate high-low voltage conditions under low short-circuit ratio through the fault voltage generation system combined with the control quantity to test the high-low voltage fault ride-through capability of the wind turbine.

[0078] Optionally, the low voltage ride through submodule is specifically used for:

[0079] The current limiting impedance and the short-circuit impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The first short-circuit switch is closed to put the system impedance, the current limiting impedance and the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the low voltage condition under low short circuit and test the low voltage fault ride-through capability of the wind turbine.

[0080] Optionally, the high voltage ride through submodule is specifically used for:

[0081] The current limiting impedance and the boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the second short-circuit switch is closed, and the system impedance, the current limiting impedance and the boost impedance are put into operation, and a voltage increase is generated at the test point to simulate the high voltage condition under low short circuit and test the high voltage fault ride-through capability of the wind turbine.

[0082] Optionally, the low-high voltage ride through submodule is specifically used for:

[0083] The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the first short-circuit switch is closed, and the system impedance, the current limiting impedance and the short-circuit impedance are put into operation, and a voltage drop is generated at the test point. After a set time period, the first short-circuit switch is disconnected to take the short-circuit impedance out of operation, and the second short-circuit switch is closed to put the boost impedance into operation, and a voltage increase is generated at the test point to simulate the low-high voltage condition under low short circuit, and test the low-high voltage fault ride-through capability of the wind turbine.

[0084] Optionally, the high-low voltage ride-through submodule is specifically used for:

[0085] The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The second short-circuit switch is closed to put the system impedance, the current limiting impedance and the boost impedance into operation, and a voltage increase is generated at the test point. After a set time interval, the second short-circuit switch is disconnected to stop the short-circuit impedance from operating. The first short-circuit switch is closed to put the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the high-low voltage condition under low short circuit and test the high-low voltage fault ride-through capability of the wind turbine.

[0086] In another aspect, the present application further provides an electronic device, comprising: at least one processor and a memory; the memory and the processor are connected via a bus;

[0087] The memory is used to store one or more programs;

[0088] When the one or more programs are executed by the at least one processor, a multi-feature fault ride-through capability testing method of a wind turbine generator system as described above is implemented.

[0089] On the other hand, the present application also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed, a method for testing the multi-feature fault ride-through capability of a wind turbine set as described above is implemented.

[0090] Compared with the prior art, the present invention has the following beneficial effects:

[0091] The present invention provides a fault voltage generation system for low short-circuit ratio simulation, including: system impedance, flow-limiting impedance, short-circuit impedance, boost impedance, first bypass switch, second bypass switch, first short-circuit switch and second short-circuit switch; the system impedance is connected in parallel with the first bypass switch; the flow-limiting impedance is connected in parallel with the second bypass switch; the short-circuit impedance is connected in series with the first short-circuit switch to form a first branch; the boost impedance is connected in series with the second short-circuit switch to form a second branch; one end of the system impedance is connected to the power grid, and the other end is connected to one end of the flow-limiting impedance, and the other end of the flow-limiting impedance is connected to a wind turbine; the first branch is connected in parallel with the second branch and connected between the flow-limiting impedance and the wind turbine. The present invention, by involving the fault voltage generation system, can flexibly adjust the voltage increase and decrease, simulate fault conditions, and provide technical support for the multi-feature fault ride-through capability test of wind turbines.

[0092] The present invention provides a method for testing the multi-feature fault ride-through capability of a wind turbine, comprising: determining the fault ride-through test type according to the test content; calculating the control amount of the parameters related to the setting requirements according to the setting requirements corresponding to the fault ride-through test type; testing the voltage fault ride-through capability of the wind turbine based on the control amount and the fault voltage generation system simulation test conditions; wherein the fault voltage generation system is a fault voltage generation system with a low short-circuit ratio simulation as described above. The present invention determines the control amount of the relevant parameters according to the fault ride-through test type, and tests the voltage fault ride-through capability of the wind turbine based on the test conditions simulated by the fault voltage generation system, thereby ensuring the safe and stable operation of the new energy power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 It is a schematic diagram of the low voltage ride-through test of the wind turbine generator set of the present invention under a low short circuit ratio of the system;

[0094] Figure 2 A flow chart of a method for testing multi-feature fault ride-through capability of a wind turbine generator system according to the present invention;

[0095] Figure 3 It is a schematic diagram of a continuous low-high voltage fault ride-through test curve of a wind turbine generator set under a low short-circuit ratio of the present invention;

[0096] Figure 4 It is a schematic diagram of a continuous high-low voltage fault ride-through test curve of a wind turbine generator set under a low short-circuit ratio of the present invention;

[0097] Figure 5 The figure is a schematic diagram of the structure of an electronic device of the present invention. DETAILED DESCRIPTION

[0098] In view of the current problems, it is urgent to establish a test method for fault ride-through of wind turbines under low short-circuit ratio, standardize the operating characteristics of wind turbines under low short-circuit ratio of the system, improve the transient operation capability of the unit, and ensure the safe and reliable operation of wind turbines connected to the system. This paper proposes a test method for the fault ride-through capability of wind turbines under low short-circuit ratio of the system, including test equipment, test content, and test steps, aiming to provide a fault ride-through test detection method under low short-circuit ratio of the system.

[0099] In order to better understand the present invention, the content of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0100] Example 1

[0101] A fault voltage generation system with low short circuit ratio simulation, such as Figure 1 As shown, including: system impedance Z v , Limited Flu Anti-X sr , short circuit impedance Z sc, boost impedance Z L , a first bypass switch CB1, a second bypass switch CB2, a first short-circuit switch CB3, and a second short-circuit switch CB4;

[0102] The system impedance Z v connected in parallel with the first bypass switch CB1;

[0103] The limited influenza anti-X sr connected in parallel with the second bypass switch CB2;

[0104] The short-circuit impedance Z sc Connected in series with the first short-circuit switch CB3 to form a first branch;

[0105] The boost impedance Z L connected in series with the second short-circuit switch CB4 to form a second branch;

[0106] The system impedance Z v One end is connected to the power grid, and the other end is connected to the limited flow anti-X sr One end is connected to the limited flu anti-X sr The other end is connected to the wind turbine;

[0107] The first branch and the second branch are connected in parallel and then connected to the flow limiting anti-X sr and between the wind turbine generator set.

[0108] The fault ride-through test of wind turbines under low short-circuit ratio includes low voltage ride-through, high voltage ride-through and continuous fault ride-through, among which continuous fault ride-through is further subdivided into continuous low-high voltage ride-through and continuous high-low voltage ride-through.

[0109] Test equipment:

[0110] In addition to conventional data acquisition equipment such as voltage and current sensors, the fault ride-through test of wind turbines under low short-circuit ratio requires the use of a fault voltage generation system with low short-circuit ratio simulation, which can generate low voltage, high voltage, continuous low-high voltage and high-low voltage changes, such as the attached Figure 1 shown.

[0111] Carry out low voltage ride-through test of wind turbines under low short circuit ratio of the system, according to the attached Figure 1 Connect the test equipment to the wind turbine to be tested. v is the system impedance (consisting of resistor R V With inductive reactance X V Composition), X sr To limit influenza resistance, Z sc is the short-circuit impedance, Z L is the boost impedance.

[0112] The present invention proposes a fault voltage generation system with low short-circuit ratio simulation. The system takes into account the network loss characteristics under low short-circuit ratio and the influence of the active / reactive power of the unit on the machine-end voltage, and can simulate the system "low short-circuit ratio + low / high voltage fault" and "low short-circuit ratio + continuous voltage fault"; the system short-circuit ratio simulation is realized by matching the system impedance with the amplitude of the limiting flow impedance, and the system network loss characteristic conditions are simulated by the impedance ratio setting, and a calculation formula is given, which is simple and easy to use; the test content of the wind turbine under the low short-circuit ratio of the system is proposed, including test conditions, test points and test curves, and detailed test steps are given.

[0113] Example 2

[0114] A multi-feature fault ride-through capability testing method for a wind turbine generator system, such as Figure 2 As shown, including:

[0115] Step S1: Determine the fault ride-through test type according to the test content;

[0116] Step S2: calculating the control amount of the parameters related to the setting requirements according to the setting requirements corresponding to the fault ride-through test type;

[0117] Step S3: testing the voltage fault ride-through capability of the wind turbine generator system based on the control variable and the fault voltage generation system simulation test condition;

[0118] The fault voltage generating system is a low short-circuit ratio simulated fault voltage generating system as described in Example 1.

[0119] Before further introducing each step in the present invention, the low short circuit ratio in the present invention is first introduced:

[0120] Short circuit ratio selection:

[0121] First, wind power exhibits different response characteristics under different short-circuit ratios, so the short-circuit ratio value is the main scenario of current concern; secondly, under the same short-circuit ratio, the ratio of different inductances to resistances directly affects the level of influence of the active power and reactive power output of the wind turbine on the terminal voltage or the level of network loss, so extra attention should be paid to the ratio of inductance to resistance.

[0122] According to the characteristics of the power grid, the level of network loss can be characterized by the impedance-to-inductance ratio X / R, that is, the ratio of inductive reactance to resistance. X / R can be set to two ranges: greater than 10 and less than or equal to 10, that is

[0123]

[0124] Considering that the short-circuit ratio of the power grid is below 3, it is a weak power grid range, and the continuous operation capacity of the new energy units is limited below 1.5, no special requirements are required, and the short-circuit ratio range is selected as 1.5~3. The short-circuit ratio value can be calculated by the following formula:

[0125]

[0126] In the formula, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively.

[0127] The following is a further description of each step:

[0128] Step S1: Determining the fault ride-through test type according to the test content includes:

[0129] When the test content is a low voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a low voltage ride-through test type;

[0130] When the test content is a high voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a high voltage ride-through test type;

[0131] When the test content is a low-high voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a low-high voltage ride-through test type;

[0132] When the test content is a high-low voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a high-low voltage ride-through test type.

[0133] Step S1 specifically includes:

[0134] Test content:

[0135] Test power range: The fault ride-through test of wind turbines under low short-circuit ratio of the system should cover the high power output of wind turbines (P ≥ 0.8P N ) and low power output (0.1P N ≤P≤0.3P N ).

[0136] The voltage fault ride-through capability of the wind turbine generator set is tested under the above two test power ranges and the short-circuit ratio of SCR=1.5-3, that is, under the four test conditions shown in Table 1. The test points of low voltage ride-through, high voltage ride-through, continuous low-high fault voltage ride-through, and continuous high-low fault voltage ride-through of the wind turbine generator set under each condition are shown in Table 2, Table 3, Table 4, and Table 5 respectively.

[0137] Table 1 Wind turbine test conditions under low short circuit ratio

[0138]

[0139] Table 2 Low voltage ride-through test points under low short circuit ratio

[0140] Serial number <![CDATA[Voltage amplitude U set (p.u.)]]> Voltage drop duration (ms) 1 0.20 625 2 0 250

[0141] Table 3 High voltage ride-through test points under low short circuit ratio

[0142] Serial number <![CDATA[Voltage amplitude U set (p.u.)]]> Voltage rise duration (ms) 1 1.25 1000 2 1.30 500

[0143] Table 4 Continuous low-high fault voltage ride-through test points under low short circuit ratio

[0144]

[0145] Table 5 Continuous high-low fault voltage ride-through test points under low short circuit ratio

[0146]

[0147]

[0148] Step S2: Calculate the control amount of the parameters related to the setting requirements according to the setting requirements corresponding to the fault ride-through test type, including:

[0149] When the fault ride-through test type is a low voltage ride-through test type, the current limiting impedance adjustment amount and the short-circuit impedance adjustment amount are calculated respectively according to the short-circuit ratio setting requirement and the voltage setting requirement of the low voltage ride-through test type;

[0150] When the fault ride-through test type is a high voltage ride-through test type, the flow limiting impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the short circuit ratio setting requirement and the voltage setting requirement of the high voltage ride-through test type;

[0151] When the fault ride-through test type is a low-high voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirement of the low-high voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the voltage drop and rise values;

[0152] When the fault ride-through test type is a high-low voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirements of the high-low voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance value adjustment amount are calculated respectively according to the voltage rise and drop values.

[0153] Step S3: Based on the control variable and the fault voltage generation system simulation test condition, the voltage fault ride-through capability of the wind turbine is tested, including:

[0154] The low voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to generate low voltage working conditions under low short circuit ratio;

[0155] The high voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to generate high voltage working conditions under low short circuit ratio;

[0156] The low-high voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to generate low-high voltage working conditions under low short-circuit ratio;

[0157] The high-low voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to produce high-low voltage conditions under low short-circuit ratio.

[0158] Furthermore, the low voltage operating condition under low short circuit ratio is generated by the fault voltage generation system in combination with the control amount to test the low voltage fault ride-through capability of the wind turbine generator, including:

[0159] The current limiting impedance and the short-circuit impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The first short-circuit switch is closed to put the system impedance, the current limiting impedance and the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the low voltage condition under low short circuit and test the low voltage fault ride-through capability of the wind turbine.

[0160] Furthermore, the high voltage operating condition under low short circuit ratio is generated by the fault voltage generation system in combination with the control amount to test the high voltage fault ride-through capability of the wind turbine generator, including:

[0161] The current limiting impedance and the boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the second short-circuit switch is closed, and the system impedance, the current limiting impedance and the boost impedance are put into operation, and a voltage increase is generated at the test point to simulate the high voltage condition under low short circuit and test the high voltage fault ride-through capability of the wind turbine.

[0162] Furthermore, the low-high voltage operating condition under low short-circuit ratio is generated by the fault voltage generation system in combination with the control amount to test the low-high voltage fault ride-through capability of the wind turbine generator, including:

[0163] The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the first short-circuit switch is closed, and the system impedance, the current limiting impedance and the short-circuit impedance are put into operation, and a voltage drop is generated at the test point. After a set time period, the first short-circuit switch is disconnected to take the short-circuit impedance out of operation, and the second short-circuit switch is closed to put the boost impedance into operation, and a voltage increase is generated at the test point to simulate the low-high voltage condition under low short circuit, and test the low-high voltage fault ride-through capability of the wind turbine.

[0164] Furthermore, the high-low voltage fault ride-through capability of the wind turbine generator set is tested by generating a high-low voltage working condition under a low short-circuit ratio by combining the fault voltage generation system with the control amount, including:

[0165] The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The second short-circuit switch is closed to put the system impedance, the current limiting impedance and the boost impedance into operation, and a voltage increase is generated at the test point. After a set time interval, the second short-circuit switch is disconnected to stop the short-circuit impedance from operating. The first short-circuit switch is closed to put the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the high-low voltage condition under low short circuit and test the high-low voltage fault ride-through capability of the wind turbine.

[0166] Steps S2 and S3 specifically include:

[0167] ① The low voltage ride-through test of wind turbines under low short-circuit ratio of the system adopts the following steps:

[0168] a) According to the attached Figure 1 Connect the test equipment;

[0169] b) Calculate the limit flow resistance X according to the short circuit ratio setting requirements sr Adjustment amount:

[0170]

[0171] c) Calculate the short-circuit impedance value Z according to the voltage setting requirements in Table 2 sc Adjustment amount:

[0172]

[0173] Where U set is the voltage setting value.

[0174] d) Disconnect the bypass switch CB1, switch on the system impedance, disconnect the bypass switch CB2, and switch on the flow-limiting impedance;

[0175] e) Close the short-circuit switch CB3, input the short-circuit impedance, and generate a voltage drop at the test point;

[0176] f) Disconnect the short-circuit switch CB3 to exit the short-circuit impedance;

[0177] g) Close the bypass switch CB2 to exit the flow-limiting impedance, and open the bypass switch CB1 to exit the system impedance.

[0178] ② The high voltage ride-through test of wind turbines under low short-circuit ratio of the system adopts the following steps:

[0179] a) According to the attached Figure 1 Connect the test equipment;

[0180] b) Calculate the limit flow resistance X according to the short circuit ratio setting requirements sr Adjustment amount:

[0181]

[0182] c) Calculate the boost impedance value Z according to the voltage setting requirements in Table 3 c Adjustment amount:

[0183]

[0184] d) Disconnect the bypass switch CB1, switch on the system impedance, disconnect the bypass switch CB2, and switch on the flow-limiting impedance;

[0185] e) Close the short-circuit switch CB4, put the boost branch into operation, and generate a voltage increase at the test point;

[0186] f) Disconnect the short-circuit switch CB4 and exit the boost branch;

[0187] g) Close the bypass switch CB2 to exit the flow-limiting impedance, and open the bypass switch CB1 to exit the system impedance.

[0188] ③Continuous low-high voltage ride-through test of wind turbines under low short-circuit ratio of the system

[0189] During the test, set the voltage drop and rise amplitude and duration according to Table 4. The test curve is shown in the attached Figure 3 , the specific test steps are as follows:

[0190] a) According to the attached Figure 1 Connect the test equipment;

[0191] b) Calculate the limit flow resistance X according to the short circuit ratio setting requirements sr Adjustment amount:

[0192]

[0193] In the formula, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively.

[0194] c) Calculate the short-circuit impedance value Z according to the voltage drop and rise values ​​in Table 4. sc , Capacitive reactance Zc adjustment amount:

[0195]

[0196] Where U 1 is the voltage drop setting value, U 2 Set the value for the voltage boost.

[0197] d) Disconnect the bypass switch CB1, switch on the system impedance, disconnect the bypass switch CB2, and switch on the flow-limiting impedance;

[0198] e) Close the short-circuit switch CB3, input the short-circuit impedance, and generate a voltage drop at the test point;

[0199] f) Disconnect the short-circuit switch CB3 to exit the short-circuit impedance;

[0200] g) Close the short-circuit switch CB4, input the boost branch, and generate a voltage increase at the test point;

[0201] h) Disconnect the short-circuit switch CB4 and exit the boost branch;

[0202] i) Disconnect the bypass switch CB2 to exit the flow-limiting impedance, and disconnect the bypass switch CB1 to exit the system impedance.

[0203] ④Continuous high-low voltage ride-through test of wind turbines under low short-circuit ratio of the system

[0204] During the test, set the voltage rise and drop amplitude and duration according to Table 5. The test curve is shown in the attached Figure 4 , the specific steps are as follows:

[0205] a) According to the attached Figure 1 Connect the test equipment;

[0206] b) Calculate the limit flow resistance X according to the short circuit ratio setting requirements sr Adjustment amount:

[0207]

[0208] In the formula, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively.

[0209] c) Calculate the short-circuit impedance value Z according to the voltage rise and drop values ​​in Table 5. sc 、Capacitive reactance Z c Adjustment amount:

[0210]

[0211] Where U 1 is the voltage drop setting value, U 2 Set the value for the voltage boost.

[0212] d) Disconnect the bypass switch CB1, switch on the system impedance, disconnect the bypass switch CB2, and switch on the flow limiting impedance;

[0213] e) Close the short-circuit switch CB4, put the boost branch into operation, and generate a voltage increase at the test point;

[0214] f) Disconnect the short-circuit switch CB4 and exit the boost branch;

[0215] g) Close the short-circuit switch CB3, input the short-circuit impedance, and generate a voltage drop at the test point;

[0216] h) Disconnect the short-circuit switch CB3 to exit the short-circuit impedance;

[0217] i) Disconnect the bypass switch CB2 to exit the flow-limiting impedance, and disconnect the bypass switch CB1 to exit the system impedance.

[0218] The present invention proposes to adopt a fault voltage generating system with low short-circuit ratio simulation, realize the system low short-circuit ratio simulation through impedance amplitude matching setting, and simulate the network loss characteristics under different short-circuit ratios through resistance-inductance ratio setting, and utilize the voltage drop and voltage increase generated by the short-circuit branch and the boost branch of the fault voltage generating system to realize single and continuous fault voltage simulation under low short-circuit ratio, thereby providing a means for fault ride-through testing of wind turbines under low short-circuit ratio.

[0219] Embodiment 3:

[0220] The present invention based on the same inventive concept also provides a multi-feature fault ride-through capability test system for a wind turbine generator set, comprising:

[0221] A test type determination module, used to determine the fault ride-through test type according to the test content;

[0222] A control quantity calculation module, used to calculate the control quantity of parameters related to the setting requirements according to the setting requirements corresponding to the fault ride-through test type;

[0223] A simulation test module, used to test the voltage fault ride-through capability of the wind turbine generator set based on the control quantity and the fault voltage generation system simulation test condition;

[0224] Wherein, the fault voltage generating system is a fault voltage generating system using a low short circuit ratio simulation as described above.

[0225] Optionally, the test type determination module is specifically used to:

[0226] When the test content is a low voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a low voltage ride-through test type;

[0227] When the test content is a high voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a high voltage ride-through test type;

[0228] When the test content is a low-high voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a low-high voltage ride-through test type;

[0229] When the test content is a high-low voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a high-low voltage ride-through test type.

[0230] Optionally, the control amount calculation module is specifically used for:

[0231] When the fault ride-through test type is a low voltage ride-through test type, the current limiting impedance adjustment amount and the short-circuit impedance adjustment amount are calculated respectively according to the short-circuit ratio setting requirement and the voltage setting requirement of the low voltage ride-through test type;

[0232] When the fault ride-through test type is a high voltage ride-through test type, the flow limiting impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the short circuit ratio setting requirement and the voltage setting requirement of the high voltage ride-through test type;

[0233] When the fault ride-through test type is a low-high voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirement of the low-high voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the voltage drop and rise values;

[0234] When the fault ride-through test type is a high-low voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirements of the high-low voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance value adjustment amount are calculated respectively according to the voltage rise and drop values.

[0235] Optionally, the flow-limiting resistance regulating amount is calculated according to the following formula:

[0236]

[0237] In the formula, X sr is the limiting resistance adjustment, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively, R V is the resistance, X V For inductive resistance.

[0238] Optionally, the short-circuit impedance adjustment amount is calculated as follows:

[0239]

[0240] In the formula, Z sc is the short-circuit impedance adjustment value, U set is the voltage setting value, U N is the rated voltage of the wind turbine, X sr To limit the amount of influenza resistance regulation, X V is the inductive reactance, R V For resistance.

[0241] Optionally, the boost impedance adjustment amount is calculated as follows:

[0242]

[0243] In the formula, Z c is the boost impedance adjustment value.

[0244] Optionally, the simulation test module includes:

[0245] The low voltage ride-through submodule is used to generate a low voltage condition with a low short-circuit ratio by combining the fault voltage generation system with the control quantity to test the low voltage fault ride-through capability of the wind turbine;

[0246] The high voltage ride-through submodule is used to generate a high voltage condition with a low short-circuit ratio by combining the fault voltage generation system with the control quantity to test the high voltage fault ride-through capability of the wind turbine;

[0247] The low-high voltage ride-through submodule is used to generate low-high voltage working conditions under low short-circuit ratio by combining the fault voltage generation system with the control quantity to test the low-high voltage fault ride-through capability of the wind turbine;

[0248] The high-low voltage ride-through submodule is used to generate high-low voltage conditions under low short-circuit ratio through the fault voltage generation system combined with the control quantity to test the high-low voltage fault ride-through capability of the wind turbine.

[0249] Optionally, the low voltage ride through submodule is specifically used for:

[0250] The current limiting impedance and the short-circuit impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The first short-circuit switch is closed to put the system impedance, the current limiting impedance and the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the low voltage condition under low short circuit and test the low voltage fault ride-through capability of the wind turbine.

[0251] Optionally, the high voltage ride through submodule is specifically used for:

[0252] The current limiting impedance and the boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the second short-circuit switch is closed, and the system impedance, the current limiting impedance and the boost impedance are put into operation, and a voltage increase is generated at the test point to simulate the high voltage condition under low short circuit and test the high voltage fault ride-through capability of the wind turbine.

[0253] Optionally, the low-high voltage ride through submodule is specifically used for:

[0254] The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the first short-circuit switch is closed, and the system impedance, the current limiting impedance and the short-circuit impedance are put into operation, and a voltage drop is generated at the test point. After a set time period, the first short-circuit switch is disconnected to take the short-circuit impedance out of operation, and the second short-circuit switch is closed to put the boost impedance into operation, and a voltage increase is generated at the test point to simulate the low-high voltage condition under low short circuit, and test the low-high voltage fault ride-through capability of the wind turbine.

[0255] Optionally, the high-low voltage ride-through submodule is specifically used for:

[0256] The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The second short-circuit switch is closed to put the system impedance, the current limiting impedance and the boost impedance into operation, and a voltage increase is generated at the test point. After a set time interval, the second short-circuit switch is disconnected to stop the short-circuit impedance from operating. The first short-circuit switch is closed to put the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the high-low voltage condition under low short circuit and test the high-low voltage fault ride-through capability of the wind turbine.

[0257] Example 4

[0258] The fault ride-through test of wind turbines under low short-circuit ratio includes low voltage ride-through, high voltage ride-through and continuous fault ride-through.

[0259] (1) Test equipment

[0260] In addition to conventional data acquisition equipment such as voltage and current sensors, the fault ride-through test of wind turbines under low short-circuit ratio requires the use of a fault voltage generation system with low short-circuit ratio simulation, which can generate low voltage, high voltage, continuous low-high voltage and high-low voltage changes, such as the attached Figure 1 shown.

[0261] Carry out low voltage ride-through test of wind turbines under low short circuit ratio of the system, according to the attached Figure 1 Connect the test equipment to the wind turbine to be tested. v is the system impedance (consisting of resistor R V With inductive reactance X V Composition), X sr To limit influenza resistance, Z sc is the short-circuit impedance, Z L is the boost impedance.

[0262] (2) Short-circuit ratio selection

[0263] First, wind power exhibits different response characteristics under different short-circuit ratios, so the short-circuit ratio value is the main scenario of current concern; secondly, under the same short-circuit ratio, the ratio of different inductances to resistances directly affects the level of influence of the active power and reactive power output of the wind turbine on the terminal voltage or the level of network loss, so extra attention should be paid to the ratio of inductance to resistance.

[0264] According to the characteristics of the power grid, the level of network loss can be characterized by the impedance-to-inductance ratio X / R, that is, the ratio of inductive reactance to resistance. X / R can be set to two ranges: greater than 10 and less than or equal to 10, that is

[0265]

[0266] Considering that the short-circuit ratio of the power grid is below 3, it is a weak power grid range, and the continuous operation capacity of the new energy units is limited below 1.5, no special requirements are required, and the short-circuit ratio range is selected as 1.5~3. The short-circuit ratio value can be calculated by the following formula:

[0267]

[0268] In the formula, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively.

[0269] (3) Test content

[0270] Test power range: The fault ride-through test of wind turbines under low short-circuit ratio of the system should cover the high power output of wind turbines (P ≥ 0.8P N ) and low power output (0.1P N ≤P≤0.3P N ).

[0271] The voltage fault ride-through capability of the wind turbine generator set is tested under the above two test power ranges and the short-circuit ratio of SCR=1.5-3, that is, under the four test conditions shown in Table 1. The test points of low voltage ride-through, high voltage ride-through, continuous low-high fault voltage ride-through, and continuous high-low fault voltage ride-through of the wind turbine generator set under each condition are shown in Table 2, Table 3, Table 4, and Table 5 respectively.

[0272] Table 1 Wind turbine test conditions under low short circuit ratio

[0273]

[0274] Table 2 Low voltage ride-through test points under low short circuit ratio

[0275] Serial number <![CDATA[Voltage amplitude U set (p.u.)]]> Voltage drop duration (ms) 1 0.20 625 2 0 250

[0276] Table 3 High voltage ride-through test points under low short circuit ratio

[0277] Serial number <![CDATA[Voltage amplitude U set (p.u.)]]> Voltage rise duration (ms) 1 1.25 1000 2 1.30 500

[0278] Table 4 Continuous low-high fault voltage ride-through test points under low short circuit ratio

[0279]

[0280] Table 5 Continuous high-low fault voltage ride-through test points under low short circuit ratio

[0281]

[0282] (4) Test steps

[0283] ① The low voltage ride-through test of wind turbines under low short-circuit ratio of the system adopts the following steps:

[0284] a) According to the attached Figure 1 Connect the test equipment;

[0285] b) Calculate the limit flow resistance X according to the short circuit ratio setting requirements sr Adjustment amount:

[0286]

[0287] c) Calculate the short-circuit impedance value Z according to the voltage setting requirements in Table 2 sc Adjustment amount:

[0288]

[0289] Where U set is the voltage setting value.

[0290] d) Disconnect the bypass switch CB1, input the system impedance, disconnect the bypass switch CB2, and input the flow limiting impedance; e) Close the short-circuit switch CB3, input the short-circuit impedance, and generate a voltage drop at the test point;

[0291] f) Disconnect the short-circuit switch CB3 to exit the short-circuit impedance;

[0292] g) Close the bypass switch CB2 to exit the flow-limiting impedance, and open the bypass switch CB1 to exit the system impedance.

[0293] ② The high voltage ride-through test of wind turbines under low short-circuit ratio of the system adopts the following steps:

[0294] a) According to the attached Figure 1 Connect the test equipment;

[0295] b) Calculate the limit flow resistance X according to the short circuit ratio setting requirements sr Adjustment amount:

[0296]

[0297] c) Calculate the boost impedance value Z according to the voltage setting requirements in Table 3 c Adjustment amount:

[0298]

[0299] d) Disconnect the bypass switch CB1, switch on the system impedance, disconnect the bypass switch CB2, and switch on the flow limiting impedance;

[0300] e) Close the short-circuit switch CB4, put the boost branch into operation, and generate a voltage increase at the test point;

[0301] f) Disconnect the short-circuit switch CB4 and exit the boost branch;

[0302] g) Close the bypass switch CB2 to exit the flow-limiting impedance, and open the bypass switch CB1 to exit the system impedance.

[0303] ③Continuous low-high voltage ride-through test of wind turbines under low short-circuit ratio of the system

[0304] During the test, set the voltage drop and rise amplitude and duration according to Table 4. The test curve is shown in the attached Figure 3 , the specific test steps are as follows:

[0305] a) According to the attached Figure 1 Connect the test equipment;

[0306] b) Calculate the limit flow resistance X according to the short circuit ratio setting requirements sr Adjustment amount:

[0307]

[0308] In the formula, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively.

[0309] c) Calculate the short-circuit impedance value Z according to the voltage drop and rise values ​​in Table 4. sc , Capacitive reactance Zc adjustment amount:

[0310]

[0311] Where U 1 is the voltage drop setting value, U 2 Set the value for the voltage boost.

[0312] d) Disconnect the bypass switch CB1, switch on the system impedance, disconnect the bypass switch CB2, and switch on the flow limiting impedance;

[0313] e) Close the short-circuit switch CB3, input the short-circuit impedance, and generate a voltage drop at the test point;

[0314] f) Disconnect the short-circuit switch CB3 to exit the short-circuit impedance;

[0315] g) Close the short-circuit switch CB4, input the boost branch, and generate a voltage increase at the test point;

[0316] h) Disconnect the short-circuit switch CB4 and exit the boost branch;

[0317] i) Disconnect the bypass switch CB2 to exit the flow-limiting impedance, and disconnect the bypass switch CB1 to exit the system impedance.

[0318] ④Continuous high-low voltage ride-through test of wind turbines under low short-circuit ratio of the system

[0319] During the test, set the voltage rise and drop amplitude and duration according to Table 5. The test curve is shown in the attached Figure 4 , the specific steps are as follows:

[0320] a) According to the attached Figure 1 Connect the test equipment;

[0321] b) Calculate the limit flow resistance X according to the short circuit ratio setting requirements sr Adjustment amount:

[0322]

[0323] In the formula, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively.

[0324] c) Calculate the short-circuit impedance value Z according to the voltage rise and drop values ​​in Table 5. sc 、Capacitive reactance Z c Adjustment amount:

[0325]

[0326] Where U 1 is the voltage drop setting value, U 2 Set the value for the voltage boost.

[0327] d) Disconnect the bypass switch CB1, switch on the system impedance, disconnect the bypass switch CB2, and switch on the flow limiting impedance;

[0328] e) Close the short-circuit switch CB4, put the boost branch into operation, and generate a voltage increase at the test point;

[0329] f) Disconnect the short-circuit switch CB4 and exit the boost branch;

[0330] g) Close the short-circuit switch CB3, input the short-circuit impedance, and generate a voltage drop at the test point;

[0331] h) Disconnect the short-circuit switch CB3 to exit the short-circuit impedance;

[0332] i) Disconnect the bypass switch CB2 to exit the flow-limiting impedance, and disconnect the bypass switch CB1 to exit the system impedance.

[0333] Example 5

[0334] like Figure 5 As shown, the present invention also provides an electronic device, which may be a computer device, a single-chip device, an intelligent mobile device, etc. The electronic device in this embodiment may include a processor, a memory, a transceiver component, etc. The memory, the processor, and the transceiver component are connected via a bus; the memory may be used to store an execution program, and an exemplary execution program may include instructions; the processor is used to execute the instructions stored in the memory. The memory may also be used to store data, which may be called and / or modified when the instructions are executed.

[0335] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in a storage medium to implement corresponding method processes or corresponding functions, so as to implement the steps of a multi-feature fault ride-through capability test method for a wind turbine set in the above-mentioned embodiment.

[0336] Example 6

[0337] Based on the same inventive concept, the present invention also provides a readable storage medium, specifically an electronic device readable storage medium (Memory), which is a memory device in the electronic device for storing programs and data. It can be understood that the storage medium here can include both the built-in storage medium in the electronic device and the extended storage medium supported by the electronic device. The storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more execution programs (including program codes). It should be noted that the storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor loads and executes one or more instructions stored in the storage medium, which can implement the steps of a multi-feature fault crossing capability test method of a wind turbine in the above embodiment.

[0338] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented 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.

[0339] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0340] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0341] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0342] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A low short-circuit ratio simulated fault voltage generation system, characterized in that: include: System impedance, current limiting impedance, short-circuit impedance, boost impedance, first bypass switch, second bypass switch, first short-circuit switch and second short-circuit switch; The system impedance is connected in parallel with the first bypass switch; The current limiting resistor is connected in parallel with the second bypass switch; The short-circuit impedance is connected in series with the first short-circuit switch to form a first branch; The boost impedance and the second short-circuit switch are connected in series to form a second branch; One end of the system impedance is connected to the power grid, and the other end is connected to one end of the flow-limiting resistor, and the other end of the flow-limiting resistor is connected to the wind turbine; The first branch and the second branch are connected in parallel and then connected between the flow-limiting reactor and the wind turbine generator set.

2. The system according to claim 1, characterized in that The system impedance includes: resistance and inductance connected in series; One end of the resistor is connected to the power grid, and the other end is connected to one end of the inductive reactance, and the other end of the inductive reactance is connected to the current limiting reactance.

3. A method for testing the multi-feature fault ride-through capability of a wind turbine generator system, characterized in that: include: Determine the fault ride-through test type based on the test content; Calculate the control amount of the parameters related to the setting requirements according to the setting requirements corresponding to the fault ride-through test type; Based on the control quantity and the fault voltage generation system simulation test condition, the voltage fault ride-through capability of the wind turbine is tested; Wherein, the fault voltage generating system is a low short-circuit ratio simulated fault voltage generating system as described in any one of claims 1 to 2.

4. The method according to claim 3, characterized in that Determining the fault ride-through test type according to the test content includes: When the test content is a low voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a low voltage ride-through test type; When the test content is a high voltage ride-through test of a wind turbine under a low short circuit ratio, the fault ride-through test type is a high voltage ride-through test type; When the test content is a low-high voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a low-high voltage ride-through test type; When the test content is a high-low voltage ride-through test of a wind turbine under a low short-circuit ratio, the fault ride-through test type is a high-low voltage ride-through test type.

5. The method according to claim 4, characterized in that The calculating, according to the setting requirements corresponding to the fault ride-through test type, the control amount of the parameters related to the setting requirements includes: When the fault ride-through test type is a low voltage ride-through test type, the current limiting impedance adjustment amount and the short-circuit impedance adjustment amount are calculated respectively according to the short-circuit ratio setting requirement and the voltage setting requirement of the low voltage ride-through test type; When the fault ride-through test type is a high voltage ride-through test type, the flow limiting impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the short circuit ratio setting requirement and the voltage setting requirement of the high voltage ride-through test type; When the fault ride-through test type is a low-high voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirement of the low-high voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance adjustment amount are calculated respectively according to the voltage drop and rise values; When the fault ride-through test type is a high-low voltage ride-through test type, the current limiting impedance adjustment amount is calculated according to the short-circuit ratio setting requirements of the high-low voltage ride-through test type, and the short-circuit impedance adjustment amount and the boost impedance value adjustment amount are calculated respectively according to the voltage rise and drop values.

6. The method according to claim 5, characterized in that The limiting flow resistance adjustment amount is calculated according to the following formula: Where, X sr is the limiting resistance adjustment, SCR is the short circuit ratio, U N , P N are the rated voltage and rated power of the wind turbine respectively, R V is the resistance, X V For inductive resistance.

7. The method according to claim 5, characterized in that The short-circuit impedance adjustment amount is calculated as follows: In the formula, Z sc is the short-circuit impedance adjustment value, U set is the voltage setting value, U N is the rated voltage of the wind turbine, X sr To limit the amount of influenza resistance regulation, X V is the inductive reactance, R V For resistance.

8. The method according to claim 7, characterized in that The boost impedance adjustment amount is calculated as follows: In the formula, Z c is the boost impedance adjustment value.

9. The method according to claim 3, characterized in that The voltage fault ride-through capability of the wind turbine generator set is tested based on the control amount and the fault voltage generation system simulation test condition, including: The low voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to generate low voltage working conditions under low short circuit ratio; The high voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to generate high voltage working conditions under low short circuit ratio; The low-high voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to generate low-high voltage working conditions under low short-circuit ratio; The high-low voltage fault ride-through capability of the wind turbine is tested by combining the fault voltage generation system with the control quantity to produce high-low voltage conditions under low short-circuit ratio.

10. The method according to claim 9, characterized in that The method of generating a low voltage working condition under a low short circuit ratio by combining a fault voltage generation system with a control amount to test the low voltage fault ride-through capability of the wind turbine generator system includes: The current limiting impedance and the short-circuit impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The first short-circuit switch is closed to put the system impedance, the current limiting impedance and the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the low voltage condition under low short circuit and test the low voltage fault ride-through capability of the wind turbine.

11. The method according to claim 9, characterized in that The method of generating a high voltage working condition under a low short circuit ratio by combining a fault voltage generation system with a control amount to test the high voltage fault ride-through capability of the wind turbine generator system includes: The current limiting impedance and the boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the second short-circuit switch is closed, and the system impedance, the current limiting impedance and the boost impedance are put into operation, and a voltage increase is generated at the test point to simulate the high voltage condition under low short circuit and test the high voltage fault ride-through capability of the wind turbine.

12. The method according to claim 9, characterized in that The method of generating a low-high voltage working condition under a low short-circuit ratio by combining a fault voltage generation system with a control amount to test the low-high voltage fault ride-through capability of the wind turbine generator includes: The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected, and the first short-circuit switch is closed, and the system impedance, the current limiting impedance and the short-circuit impedance are put into operation, and a voltage drop is generated at the test point. After a set time period, the first short-circuit switch is disconnected to take the short-circuit impedance out of operation, and the second short-circuit switch is closed to put the boost impedance into operation, and a voltage increase is generated at the test point to simulate the low-high voltage condition under low short circuit, and test the low-high voltage fault ride-through capability of the wind turbine.

13. The method according to claim 9, characterized in that The high-low voltage fault ride-through capability of the wind turbine generator set is tested by generating a high-low voltage working condition under a low short-circuit ratio by combining the fault voltage generation system with the control amount, including: The current limiting impedance, short-circuit impedance and boost impedance are regulated according to the regulation amount, and the first bypass switch and the second bypass switch are disconnected. The second short-circuit switch is closed to put the system impedance, the current limiting impedance and the boost impedance into operation, and a voltage increase is generated at the test point. After a set time interval, the second short-circuit switch is disconnected to stop the short-circuit impedance from operating. The first short-circuit switch is closed to put the short-circuit impedance into operation, and a voltage drop is generated at the test point to simulate the high-low voltage condition under low short circuit and test the high-low voltage fault ride-through capability of the wind turbine.

14. A multi-feature fault ride-through capability test system for a wind turbine generator set, characterized in that: include: A test type determination module, used to determine the fault ride-through test type according to the test content; A control quantity calculation module, used to calculate the control quantity of parameters related to the setting requirements according to the setting requirements corresponding to the fault ride-through test type; A simulation test module, used to test the voltage fault ride-through capability of the wind turbine generator set based on the control quantity and the fault voltage generation system simulation test condition; Wherein, the fault voltage generating system is a low short-circuit ratio simulated fault voltage generating system as described in any one of claims 1 to 2.

15. An electronic device, characterized in that: include: at least one processor and memory; The memory and the processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, a multi-feature fault ride-through capability testing method for a wind turbine set as described in any one of claims 3 to 13 is implemented.

16. A readable storage medium, characterized in that: An execution program is stored thereon, and when the execution program is executed, a multi-feature fault ride-through capability testing method for a wind turbine set according to any one of claims 1 to 13 is implemented.

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