A wind turbine grid-connected test device

Abstract

The present application discloses a wind turbine grid-connected test device, including: a grid disturbance generating device connected to the grid side; a grid fault simulation generating device connected to the wind turbine to be tested and the grid disturbance generating device respectively; a test device integrated monitoring system connected to the grid disturbance generating device and the grid fault simulation generating device respectively; the grid disturbance generating device is used to test the grid adaptability of the wind turbine to be tested; the grid disturbance generating device and the grid fault simulation generating device are combined to test the fault voltage ride-through capability of the wind turbine to be tested; the test device integrated monitoring system is used to monitor and remotely control the grid disturbance generating device and the grid fault simulation generating device. The present application can better optimize the performance of the test device, improve the test efficiency, reduce the overall cost of the device, and improve the reliability of the device by integrating the grid disturbance generating device and the grid fault simulation generating device.

Description

Technical Field

[0001] The present application relates to the technical field of wind turbine testing, and in particular to a wind turbine grid-connected testing device. Background Art

[0002] There have been many wind turbine disconnection accidents in China caused by low voltage and low ride-through of wind turbines and insufficient adaptability of the power grid. In order to avoid wind turbine disconnection accidents, test and detection methods are often used to ensure that wind turbines connected to the power grid meet the operation requirements of the power grid, reduce the risk of abnormal disconnection of wind turbines / wind farms, and improve the safe operation of power grids with large-scale wind farms. The grid-connected test device of wind turbines is a key equipment for realizing the grid-connected performance test of wind turbines, and has received extensive attention from scholars and equipment manufacturers at home and abroad.

[0003] In the existing scheme, a grid disturbance generator is generally used to test the grid adaptability of wind turbines, and a grid fault simulation device is used to test the fault voltage ride-through capability of wind turbines. The grid disturbance generator and the grid fault simulation device are currently generally implemented separately through two sets of devices, which are relatively independent in design and tested separately during the test process, resulting in high equipment cost, slow test speed and low efficiency. Summary of the invention

[0004] The embodiment of the present application provides a wind turbine grid-connected testing device, which optimizes the performance of the testing device, improves the testing efficiency, reduces the overall cost of the device, and improves the reliability of the device.

[0005] In view of this, the present application provides a wind turbine grid-connected testing device, the device comprising:

[0006] A grid disturbance generating device connected to the grid side;

[0007] A power grid fault simulation generating device connected to the wind turbine set under test and the power grid disturbance generating device respectively;

[0008] A test device integrated monitoring system respectively communicatively connected to the power grid disturbance generating device and the power grid fault simulation generating device;

[0009] The grid disturbance generating device is used to test the grid adaptability of the wind turbine being tested;

[0010] The power grid disturbance generating device and the power grid fault simulation generating device are combined to test the fault voltage ride-through capability of the wind turbine under test;

[0011] The test device integrated monitoring system is used to perform status monitoring and remote control on the power grid disturbance generating device and the power grid fault simulation generating device.

[0012] Optionally, the grid adaptability includes wind turbine voltage deviation adaptability, frequency deviation adaptability, three-phase voltage imbalance adaptability, flicker adaptability, and harmonic voltage adaptability.

[0013] Optionally, the fault voltage ride-through capability includes low voltage ride-through, high voltage ride-through and voltage cascading fault tests of the wind turbine set.

[0014] Optionally, the power grid disturbance generating device includes a first circuit breaker, an AC / DC / AC power electronic power converter and a second circuit breaker connected in series in sequence, and also includes a first bypass circuit breaker connected in parallel at both ends of the first circuit breaker and the AC / DC / AC power electronic power converter connected in series in sequence.

[0015] Optionally, the AC / DC / AC power electronic power converter includes a first connection transformer, three first phase units connected to the three-phase output of the first connection transformer, and the three first phase units are connected in parallel;

[0016] It also includes a second connection transformer, three second phase units and a smoothing reactor. The three-phase input ends of the second connection transformer are respectively connected to the three second phase units, the three second phase units are connected in parallel, the first phase unit is connected to the smoothing reactor, and the other end of the smoothing reactor is connected to the second phase unit.

[0017] Optionally, the phase unit includes several submodules.

[0018] Optionally, the submodule is a half-bridge submodule or a full-bridge submodule or a clamped dual submodule circuit.

[0019] Optionally, the power grid fault simulation generating device includes:

[0020] The third circuit breaker, the current limiting reactor and the fourth circuit breaker connected in series in sequence;

[0021] A second bypass circuit breaker connected in parallel to the third circuit breaker, the current limiting reactor and two ends of the fourth circuit breaker which are sequentially connected in series.

[0022] Optionally, one end of the current-limiting reactance is connected to the fifth circuit breaker and the sixth circuit breaker;

[0023] The other end of the fifth circuit breaker is connected to a short-circuit reactance, and the other end of the short-circuit reactance is grounded;

[0024] The sixth circuit breaker, the boost branch capacitor and the boost branch resistor are connected in series in sequence, and the other end of the boost branch resistor is grounded.

[0025] Optionally, the output of the grid side is connected to the other end of the first circuit breaker, the other end of the second circuit breaker is connected to the other end of the third circuit breaker, and the other end of the fourth circuit breaker is connected to the wind turbine set under test.

[0026] It can be seen from the above technical solutions that this application has the following advantages:

[0027] In an embodiment of the present application, a wind turbine grid-connected test device is provided, comprising a grid disturbance generating device connected to a grid side; a grid fault simulation generating device respectively connected to the wind turbine to be tested and the grid disturbance generating device; a test device integrated monitoring system respectively communicatively connected to the grid disturbance generating device and the grid fault simulation generating device; the grid disturbance generating device is used to test the grid adaptability of the wind turbine to be tested; the grid disturbance generating device and the grid fault simulation generating device are combined to test the fault voltage ride-through capability of the wind turbine to be tested; the test device integrated monitoring system is used to perform status monitoring and remote control of the grid disturbance generating device and the grid fault simulation generating device.

[0028] The present application integrates the power grid disturbance generating device and the power grid fault simulation generating device into an integrated design, which can better optimize the performance of the test device, improve the test efficiency, reduce the overall cost of the device, and improve the reliability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural schematic diagram of an embodiment of a wind turbine grid-connected testing device of the present application;

[0030] Figure 2 This is a circuit diagram of a grid disturbance generating device in one embodiment of a wind turbine grid-connected testing device of the present application;

[0031] Figure 3 This is a circuit diagram of an AC / DC / AC power electronic power converter in one embodiment of a wind turbine grid-connected test device of the present application;

[0032] Figure 4 A circuit diagram of a submodule of the AC / DC / AC power electronic power converter of this application;

[0033] Figure 5 This is a circuit diagram of a power grid fault simulation device in this application;

[0034] Figure 6 A schematic diagram of the connection between the power grid disturbance generating device and the power grid fault simulation generating device in this application;

[0035] Figure 7This is a flow chart of the main circuit parameter design method of the grid-connected test device in this application. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] See also Figure 1 , Figure 1 FIG. 1 is a schematic diagram of a wind turbine grid-connected test device according to an embodiment of the present invention. Figure 1 As shown, Figure 1 middle:

[0038] A grid disturbance generating device connected to the grid side.

[0039] It should be noted that the power grid disturbance generating device may include a first circuit breaker, an AC / DC / AC power electronic power converter and a second circuit breaker connected in series in sequence, and also includes a first bypass circuit breaker connected in parallel to both ends of the first circuit breaker and the AC / DC / AC power electronic power converter connected in series in sequence. The AC / DC / AC power electronic power converter is a multi-level power converter that can realize AC / DC / AC two-level conversion, specifically Figure 2 As shown, the circuit breaker QF11 is the first circuit breaker, the circuit breaker QF12 is the second circuit breaker, and the bypass circuit breaker QF13 is the first bypass circuit breaker.

[0040] In a specific embodiment, Figure 3 It is one of the implementation schemes based on modular multilevel converter (MMC). Among them, the AC / DC / AC power electronic power converter may include: a first connection transformer, three first phase units connected to the three-phase output of the first connection transformer, and the three first phase units are connected in parallel; it also includes a second connection transformer, three second phase units and a smoothing reactor, the three-phase input ends of the second connection transformer are respectively connected to the three second phase units, the three second phase units are connected in parallel, the first phase unit is connected to the smoothing reactor, and the other end of the smoothing reactor is connected to the second phase unit. Figure 3 The connection transformer on the left side is a first connection transformer, and the phase unit connected to the first connection transformer is a first phase unit; Figure 3The connection transformer on the right side is the second connection transformer, and the phase unit connected to the second connection transformer is the second phase unit. It should also be noted that the AC / DC / AC power electronic power converter of the power grid disturbance generating device is not limited to Figure 3 The modular multi-level structure can replace all power electronic power converter circuits that can realize the AC / DC / AC power conversion function as long as it can realize the grid adaptability test function of the wind turbine.

[0041] In a specific embodiment, the phase unit in the AC / DC / AC power electronic power converter includes several submodules, and the submodules can be half-bridge submodules, full-bridge submodules, or clamped dual submodule circuits. Figure 4 As shown, Figure 4 (a) is a half-bridge submodule, Figure 4 (b) is a full-bridge submodule, Figure 4 (c) is a clamping type dual module circuit.

[0042] A power grid fault simulation generating device is respectively connected to the wind turbine set under test and the power grid disturbance generating device.

[0043] It should be noted that the power grid fault simulation device may include: a third circuit breaker, a current limiting reactor and a fourth circuit breaker connected in series in sequence; and a second bypass circuit breaker connected in parallel to both ends of the third circuit breaker, the current limiting reactor and the fourth circuit breaker connected in series in sequence. One end of the current limiting reactor is connected to the fifth circuit breaker and the sixth circuit breaker; the other end of the fifth circuit breaker is connected to the short-circuit reactor, and the other end of the short-circuit reactor is grounded; the sixth circuit breaker, the boost branch capacitor and the boost branch resistor are connected in series in sequence, and the other end of the boost branch resistor is grounded. Among them, circuit breaker QF21 is the third circuit breaker, circuit breaker QF22 is the fourth circuit breaker, circuit breaker QF24 is the fifth circuit breaker, circuit breaker QF25 is the sixth circuit breaker, and bypass circuit breaker QF23 is the second bypass circuit breaker. The main circuit structure of the power grid fault simulation device is as follows: Figure 5 shown.

[0044] The design of the parameters of the current limiting reactance, short-circuit reactance, and boost branch capacitor in the circuit of the power grid fault simulation device is the most critical and complex. The main reason is that the short-circuit capacity parameters on the power grid side vary greatly in different test environments. Some wind farms are located in remote areas with weak systems and short-circuit capacity of only tens of MVA, while some wind farms are connected to stronger systems and short-circuit capacity may reach hundreds of MVA. Therefore, when testing the fault voltage ride-through capability of the wind turbine, the power grid disturbance generator and the power grid fault simulation generator are connected at the same time, such as Figure 6As shown, since the power grid fault simulation generating device is connected to the power grid through the power grid disturbance generating device, the AC / DC / AC power electronic power converter of the power grid disturbance generating device realizes the isolation between the power grid and the power grid fault simulation generating device, that is, the AC / DC / AC power electronic power converter can be regarded as a voltage source with a fixed short-circuit capacity for the power grid fault simulation generating device, and the power grid fault simulation generating device will no longer be affected by the short-circuit capacity on the power grid side, thereby greatly simplifying the parameter design of the current limiting reactance, short-circuit reactance, and boost branch capacitor of the power grid fault simulation generating device.

[0045] In a specific embodiment, the output of the grid side is connected to the other end of the first circuit breaker, the other end of the second circuit breaker is connected to the other end of the third circuit breaker, and the other end of the fourth circuit breaker is connected to the wind turbine set under test.

[0046] A comprehensive monitoring system for a test device which is communicatively connected to a power grid disturbance generating device and a power grid fault simulation generating device respectively.

[0047] It should be noted that the comprehensive monitoring system of the test device can monitor the electrical signals in the power grid disturbance generating device and the power grid fault simulation generating device in real time, and can analyze the electrical signals and remotely control the power grid disturbance generating device and the power grid fault simulation generating device.

[0048] The grid disturbance generator is used to test the grid adaptability of the wind turbine under test.

[0049] It should be noted that the grid disturbance generator can be designed between the grid side and the grid fault simulation generator to isolate the grid side from the grid fault simulation generator, and can also be used to measure the adaptability of the wind turbine. The grid adaptability can include the voltage deviation adaptability, frequency deviation adaptability, three-phase voltage unbalance adaptability, flicker adaptability, and harmonic voltage adaptability of the wind turbine.

[0050] The combination of a power grid disturbance generator and a power grid fault simulation generator is used to test the fault voltage ride-through capability of the wind turbine under test.

[0051] It should be noted that the combination of the power grid disturbance generator and the power grid fault simulation generator can better optimize the performance of the test device, improve the test efficiency, reduce the overall cost of the device, and improve the reliability of the device by integrating the power grid disturbance generator and the power grid fault simulation generator into an integrated design. The fault voltage ride-through capability can include low voltage ride-through, high voltage ride-through and voltage cascading fault tests for wind turbines.

[0052] The test device integrated monitoring system is used for status monitoring and remote control of power grid disturbance generating devices and power grid fault simulation generating devices.

[0053] It should be noted that the comprehensive monitoring system of the test device can be communicatively connected with the power grid disturbance generating device and the power grid fault simulation generating device, and the input interface of the comprehensive monitoring system of the test device can be connected between the power grid side and the power grid disturbance generating device, and the output interface of the comprehensive monitoring system of the test device can be connected between the wind turbine set under test and the power grid fault simulation generating device, so as to realize status monitoring and remote control of the power grid disturbance generating device and the power grid fault simulation generating device.

[0054] The present application integrates the design of a power grid disturbance generating device and a power grid fault simulation generating device, thereby being able to better optimize the performance of the test device, improve the test efficiency, reduce the overall cost of the device, and improve the reliability of the device.

[0055] This application also includes a main circuit parameter design method for the grid-connected test device, which can be referenced Figure 7 . Specifically, it includes: designing the main circuit parameters of the grid disturbance generating device according to the type and maximum capacity of the wind turbines that need to be tested by the grid-connected test device, as well as the grid adaptability test function and performance index requirements, and calculating the short-circuit impedance parameters at the output end of the grid disturbance generating device. Designing the main circuit parameters of the grid fault simulation generating device according to the type and maximum capacity of the wind turbines that need to be tested by the grid-connected test device, the short-circuit impedance parameters at the output end of the grid disturbance generating device, and the fault voltage ride-through capability test function and performance index requirements. The main circuit parameters of the integrated wind turbine grid-connected test device can be finally obtained based on the main circuit parameters of the grid disturbance generating device and the main circuit parameters of the grid fault simulation generating device.

[0056] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0057] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0058] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0059] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A wind turbine grid-connected test device, characterized in that: include: A grid disturbance generating device connected to the grid side; A power grid fault simulation generating device connected to the wind turbine set under test and the power grid disturbance generating device respectively; A test device integrated monitoring system respectively communicatively connected to the power grid disturbance generating device and the power grid fault simulation generating device; The grid disturbance generating device is used to test the grid adaptability of the wind turbine being tested; The power grid disturbance generating device and the power grid fault simulation generating device are combined to test the fault voltage ride-through capability of the wind turbine under test; The test device integrated monitoring system is used to monitor and remotely control the power grid disturbance generating device and the power grid fault simulation generating device; The power grid disturbance generating device comprises a first circuit breaker, an AC / DC / AC power electronic power converter and a second circuit breaker connected in series in sequence, and also comprises a first bypass circuit breaker connected in parallel to both ends of the first circuit breaker and the AC / DC / AC power electronic power converter connected in series in sequence; The power grid fault simulation generating device comprises: The third circuit breaker, the current limiting reactor and the fourth circuit breaker connected in series in sequence; A second bypass circuit breaker connected in parallel to the third circuit breaker, the current limiting reactor and both ends of the fourth circuit breaker which are sequentially connected in series; One end of the current limiting reactor is connected to the fifth circuit breaker and the sixth circuit breaker; The other end of the fifth circuit breaker is connected to a short-circuit reactance, and the other end of the short-circuit reactance is grounded; The sixth circuit breaker, the boost branch capacitor and the boost branch resistor are connected in series in sequence, and the other end of the boost branch resistor is grounded; The output of the grid side is connected to the other end of the first circuit breaker, the other end of the second circuit breaker is connected to the other end of the third circuit breaker, and the other end of the fourth circuit breaker is connected to the wind turbine set under test.

2. The wind turbine grid-connected testing device according to claim 1, characterized in that: The grid adaptability includes voltage deviation adaptability, frequency deviation adaptability, three-phase voltage imbalance adaptability, flicker adaptability and harmonic voltage adaptability of wind turbines.

3. The wind turbine grid-connected testing device according to claim 1, characterized in that: The fault voltage ride-through capability includes low voltage ride-through, high voltage ride-through and voltage cascading fault tests of wind turbines.

4. The wind turbine grid-connected test device according to claim 1, characterized in that: The AC / DC / AC power electronic power converter comprises a first connection transformer, three first phase units connected to the three-phase output of the first connection transformer, and the three first phase units are connected in parallel; It also includes a second connection transformer, three second phase units and a smoothing reactor. The three-phase input ends of the second connection transformer are respectively connected to the three second phase units, the three second phase units are connected in parallel, the first phase unit is connected to the smoothing reactor, and the other end of the smoothing reactor is connected to the second phase unit.

5. The wind turbine grid-connected testing device according to claim 4, characterized in that: The phase unit includes several submodules.

6. The wind turbine grid-connected test device according to claim 5, characterized in that: The submodule is a half-bridge submodule or a full-bridge submodule or a clamped dual submodule circuit.

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