Converter testing device
By designing a converter test device that includes grid voltage and motor voltage simulation modules, the problem of adapting the converter test device to low-frequency operating conditions was solved, realizing low-cost converter performance verification and protection, and reducing the cost of building a motor-to-drive test bench.
Patent Information
- Application Number
- CN202423227879.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2034-12-25
AI Technical Summary
Existing converter testing equipment is insufficient to meet the testing requirements under low-frequency operating conditions, and the construction of motor-driven test benches is costly and cannot be adapted to low-frequency AC power grid and generator voltage characteristic testing.
Design a converter testing device, including a grid voltage simulation module and a generator voltage simulation module. By simulating grid voltage and generator voltage of different frequencies and amplitudes, the device enables performance testing of the converter's grid-side and generator-side terminals under different operating conditions. Furthermore, the device isolates the current loop through a power circulation module, thereby reducing construction costs.
It enables low-cost simulation of the field operation conditions of the converter, and can verify the performance of the internal power devices of the converter at different frequencies and amplitudes, prevent the short-circuit current of the power circuit from amplifying, and protect the devices from damage.
Smart Images
Figure CN223711736U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of power conversion technology, and more particularly to a converter testing device. Background Technology
[0002] Currently, the wind turbine converter under test is connected to the power grid on the grid side and to the motor on the turbine side. The AC voltage frequencies and amplitudes on the turbine and grid sides of the wind turbine converter under test are inconsistent. Therefore, to accurately simulate the actual operating conditions of the wind turbine converter and test its performance, a motor-to-motor test bench is needed. However, as the power rating of wind turbine generators increases, the construction cost of such a test bench is rising. Furthermore, as offshore wind power development moves towards deeper waters, the transmission method of wind power has changed. Flexible low-frequency AC output is one such method, meaning the grid connected to the wind turbine converter is no longer the power frequency grid but a low-frequency AC grid. However, existing converter testing equipment is insufficient to meet the testing requirements under low-frequency conditions. Utility Model Content
[0003] This disclosure provides a converter testing device to simulate the field operating conditions of a converter at low cost, and to provide the converter with grid voltage and generator voltage of different frequencies and amplitudes to fully verify the performance of the power devices inside the converter.
[0004] This disclosure provides a converter testing device, which includes a grid voltage simulation module, a motor voltage simulation module, and a power cycling module.
[0005] The first end of the power circulation module and the first end of the power grid voltage simulation module are both connected to the power frequency grid. The first end of the motor voltage simulation module is connected to the second end of the power circulation module. The power circulation module is used to isolate the current loop between the power frequency grid and the power grid voltage simulation module and the motor voltage simulation module.
[0006] The second end of the grid voltage simulation module is used to connect to the grid side of the converter, and the second end of the motor voltage simulation module is used to connect to the generator side of the converter. The grid voltage simulation module is used to simulate grid voltages of different frequencies and amplitudes, and the motor voltage simulation module is used to simulate generator voltages of different frequencies and amplitudes, so that the grid side and generator side of the converter can be tested under AC voltages of different frequencies and amplitudes.
[0007] Optionally, the grid voltage simulation module includes a first test converter and a first filter unit;
[0008] The grid-side terminal of the first auxiliary converter serves as the first terminal of the grid voltage simulation module, the machine-side terminal of the first auxiliary converter is connected to the first terminal of the first filter unit, and the second terminal of the first filter unit serves as the second terminal of the grid voltage simulation module.
[0009] Optionally, the first test converter includes a first AC-DC-AC converter;
[0010] The first input / output terminal of the first AC-DC-AC converter serves as the grid-side terminal of the first auxiliary converter, and the second input / output terminal of the first AC-DC-AC converter serves as the machine-side terminal of the first auxiliary converter.
[0011] Optionally, the first filtering unit includes a first LCL-type filter;
[0012] The first end of the first LCL filter serves as the first end of the first filtering unit, and the second end of the first LCL filter serves as the second end of the first filtering unit.
[0013] Optionally, the motor voltage simulation module includes a second test converter and a second filter unit;
[0014] The first end of the second filter unit serves as the second end of the motor voltage simulation module. The second end of the second filter unit is connected to the machine side end of the second auxiliary converter. The grid side end of the second auxiliary converter serves as the first end of the motor voltage simulation module.
[0015] Optionally, the second test converter includes a second AC-DC-AC converter;
[0016] The first input / output terminal of the second AC-DC-AC converter serves as the grid-side terminal of the second auxiliary converter, and the second input / output terminal of the second AC-DC-AC converter serves as the machine-side terminal of the second auxiliary converter.
[0017] Optionally, the second filtering unit includes a second LCL-type filter;
[0018] The first end of the second LCL filter serves as the first end of the second filtering unit, and the second end of the second LCL filter serves as the second end of the second filtering unit.
[0019] Optionally, the power circulation module includes a power circulation transformer;
[0020] The first end of the power circulation transformer serves as the first end of the power circulation module, and the second end of the power circulation transformer serves as the second end of the power circulation module.
[0021] Compared to related technologies, this disclosure utilizes a grid voltage simulation module to convert AC power input from the power frequency grid into AC power of different frequencies and amplitudes, thereby simulating grid voltages of different frequencies and amplitudes to provide the converter's grid-side terminal with grid voltages of different frequencies and amplitudes. Similarly, a motor voltage simulation module converts AC power input from the power frequency grid, converted by a power circulation module, into AC power of different frequencies and amplitudes, thereby simulating generator voltages of different frequencies and amplitudes to provide the converter's grid-side terminal with generator voltages of different frequencies and amplitudes. Therefore, this disclosure can simulate the converter's field operating conditions at low cost, providing the converter with grid voltages and generator voltages of different frequencies and amplitudes to fully verify the performance of the converter's internal power devices. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 A schematic diagram of a converter production and testing platform provided for related technologies;
[0024] Figure 2 This is a schematic diagram of the structure of a converter testing device provided in an embodiment of the present disclosure;
[0025] Figure 3 A schematic diagram of another converter testing device provided in an embodiment of this disclosure. Detailed Implementation
[0026] To enable those skilled in the art to better understand the present disclosure, the technical solutions of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present disclosure, and not all embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present disclosure.
[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0028] Figure 1 A schematic diagram of a converter production and testing platform provided for related technologies, such as... Figure 1 As shown, the converter production test platform includes a power circulation transformer 11 and an external filter 12. The first terminal of the power circulation transformer 11 and the power frequency grid 20 are both connected to the grid-side terminal of the converter 21. The machine-side terminal of the converter 21 is connected to the second terminal of the power circulation transformer 11 via the external filter 12. Energy exchange between the grid-side and machine-side terminals of the converter 21 can be achieved through the power circulation transformer 11, thereby enabling full-power load testing of the converter 21 to verify whether its performance indicators before leaving the factory meet the requirements and whether there are any abnormalities in the power circuit components.
[0029] However, wind turbine converters are connected to the power grid on the grid side and to the motor on the turbine side. The AC voltage frequencies and amplitudes on the turbine and grid sides of the wind turbine converter under test are inconsistent. Therefore, to accurately simulate the actual operating environment of the wind turbine converter, a motor-to-motor test bench is needed. As the power rating of wind turbine generators increases, the construction cost of such test benches is rising. Furthermore, as offshore wind power development moves towards deeper waters, the transmission of offshore wind power is increasingly dominated by flexible low-frequency AC output. This means that the grid connected to the wind turbine converter is no longer the power frequency grid, but a low-frequency AC grid. Existing converter manufacturing plants often only have power frequency grids, and the grid voltage amplitude cannot be adjusted over a wide range. Therefore, the production and testing process cannot adapt the wind turbine converter under test to a low-frequency grid, and with limited budget, it is impossible to fully verify the variable frequency motor voltage characteristics on the turbine side of the wind turbine converter under test.
[0030] To address the aforementioned issues, this disclosure provides a converter testing device that can simulate the on-site operating conditions of a converter at low cost, providing the converter with grid voltages and generator voltages of different frequencies and amplitudes to fully verify the performance of the power devices inside the converter.
[0031] Figure 2 This is a schematic diagram of the structure of a converter testing device provided in an embodiment of this disclosure, as shown below. Figure 2 As shown, the converter testing device includes a grid voltage simulation module 110, a motor voltage simulation module 120, and a power circulation module 130.
[0032] The first end of the power circulation module 130 and the first end of the grid voltage simulation module 110 are both connected to the power frequency grid 20. The first end of the motor voltage simulation module 120 is connected to the second end of the power circulation module 130. The power circulation module 130 is used to isolate the current loop between the power frequency grid 20 and the grid voltage simulation module 110 and the motor voltage simulation module 120.
[0033] The second terminal of the grid voltage simulation module 110 is used to connect to the grid side of the converter 21, and the second terminal of the motor voltage simulation module 120 is used to connect to the generator side of the converter 21; 2121; The grid voltage simulation module 110 is used to simulate grid voltages of different frequencies and amplitudes, and the motor voltage simulation module 120 is used to simulate generator voltages of different frequencies and amplitudes, so that the grid side and generator side of the converter 21 can be tested under AC voltages of different frequencies and amplitudes.
[0034] The grid voltage simulation module 110 can convert the AC power input from the power frequency grid 20 into AC power of different frequencies and amplitudes, thereby simulating grid voltages of different frequencies and amplitudes to provide grid voltages of different frequencies and amplitudes to the grid side of the converter 21. Therefore, the grid voltage simulation module 110 can be used to adapt the grid side of the converter 21 to a low-frequency grid.
[0035] Since the AC voltage frequencies and amplitudes at the first terminals of the power grid voltage simulation module 110 and the motor voltage simulation module 120 are inconsistent, the power circulation module 130 can isolate the current loops between the power frequency power grid 20 and the power grid voltage simulation module 110 and the motor voltage simulation module 120, based on the energy interaction between the power frequency power grid 20 and the power grid voltage simulation module 110 and the motor voltage simulation module 120.
[0036] The motor voltage simulation module 120 can convert the AC power input from the power frequency grid 20 through the power circulation module 130 into AC power of different frequencies and amplitudes, thereby simulating generator voltages of different frequencies and amplitudes to provide generator voltages of different frequencies and amplitudes to the grid side of the converter 21. Therefore, compared to establishing a motor-to-torque test bench to simulate generator voltage using the motor voltage simulation module 120, the construction cost is lower, the range of generator voltages that can be simulated is wider, and the construction cost does not increase with the power level of the wind turbine generator set.
[0037] Therefore, this disclosure enables the grid-side terminal of the simulated converter 21 to be connected to the grid voltage that can provide different frequencies and amplitudes, and the generator-side terminal of the converter 21 to be connected to the generator voltage that can provide different frequencies and amplitudes. This allows for the simulation of the field operating conditions of the converter 21 at low cost, and can fully verify the performance of the power devices inside the converter.
[0038] In addition, during the current production and testing of converters, if a power device fails, i.e. a short circuit occurs in the power circuit, the power semiconductor device will be subjected to a large short-circuit current for a certain period of time due to the time delay protection of devices such as circuit breakers or fuses. This will cause the failure range of power semiconductor devices with limited current overload capacity to expand, meaning that in addition to the failure of the faulty device, normal semiconductor power devices will also be damaged.
[0039] To address the aforementioned issues, the grid voltage simulation module 110 and motor voltage simulation module 120 used in this disclosure can both detect the current output by the converter 21 in real time. When an overcurrent is detected in the current output by the converter 21, the power input circuit of the power frequency grid 20 is quickly cut off, thereby forcing the converter 21 to stop operating. This reduces the short-circuit current borne by the short circuit in the power circuit of the converter and prevents the scope of device failure from expanding.
[0040] Based on the above embodiments, optionally, Figure 3 A schematic diagram of another converter testing device provided in an embodiment of this disclosure. Figure 3 As shown, the grid voltage simulation module 110 includes a first test converter 111 and a first filter unit 112; the grid-side end of the first test converter 111 serves as the first end of the grid voltage simulation module 110, the machine-side end of the first test converter 111 is connected to the first end of the first filter unit 112, and the second end of the first filter unit 112 serves as the second end of the grid voltage simulation module 110.
[0041] Specifically, the grid-side terminal of the first auxiliary converter 111 is connected to the power frequency grid 20 and the first terminal of the power circulation module 130, and the second terminal of the first filter unit 112 is connected to the grid-side terminal of the converter 21. The grid-side portion of the first auxiliary converter 111 employs a control strategy to stabilize the DC bus voltage, thereby achieving the function of stabilizing the DC bus voltage. The generator-side portion of the first auxiliary converter 111 employs a variable-frequency output control strategy to achieve the output of variable-frequency AC voltage, that is, to enable the first auxiliary converter 111 to output AC power of different frequencies and amplitudes.
[0042] The first auxiliary converter 111 can convert the AC power input from the power frequency grid 20 into AC power of different frequencies and amplitudes, thereby simulating grid voltages of different frequencies and amplitudes to provide grid voltages of different frequencies and amplitudes to the grid side of converter 21. The first filter unit 112 can filter the grid voltages of different frequencies and amplitudes converted by the first auxiliary converter 111 to filter out voltage harmonics that do not meet the requirements of the grid voltage, so as to ensure that the harmonics of the grid voltage input to converter 21 meet the operating requirements of converter 21.
[0043] Based on the above embodiments, optionally, the first test converter 111 includes a first AC-DC-AC converter;
[0044] The first input / output terminal of the first AC-DC-AC converter serves as the grid-side terminal of the first test converter 111, and the second input / output terminal of the first AC-DC-AC converter serves as the machine-side terminal of the first test converter 111.
[0045] The first AC-DC-AC converter can collect the first current output from the grid side of the converter 21. When the first AC-DC-AC converter detects that the first current exceeds the set current threshold (the maximum current that the power devices of the AC-DC-AC converter can withstand), it will stop operating, thereby quickly disconnecting the power input circuit of the power frequency grid 20, thereby reducing the short-circuit current that the power circuit of the converter is subjected to and preventing the failure range of the devices from expanding.
[0046] Based on the above embodiments, optionally, the first filtering unit 112 includes a first LCL type filter; the first end of the first LCL type filter serves as the first end of the first filtering unit 112, and the second end of the first LCL type filter serves as the second end of the first filtering unit 112.
[0047] Based on the above embodiments, alternatively, refer to the following: Figure 3The motor voltage simulation module 120 includes a second test converter 121 and a second filter unit 121; the first end of the second filter unit 121 serves as the second end of the motor voltage simulation module 120, the second end of the second filter unit 121 is connected to the machine side end of the second test converter 121, and the grid side end of the second test converter 121 serves as the first end of the motor voltage simulation module 120.
[0048] Specifically, the grid-side terminal of the second auxiliary converter 121 is connected to the second terminal of the power circulation module 130, and the first terminal of the second filter unit 121 is connected to the machine-side terminal of the converter 21. The grid-side portion of the second auxiliary converter 121 employs a control strategy to stabilize the DC bus voltage, thereby achieving the function of stabilizing the DC bus voltage. The machine-side portion of the second auxiliary converter 121 employs a variable-frequency output control strategy to achieve the output of variable-frequency AC voltage, that is, to enable the second auxiliary converter 121 to output AC power of different frequencies and amplitudes.
[0049] The second auxiliary converter 121 can convert the AC power input from the power frequency grid 20 through the power circulation module 130 into AC power of different frequencies and amplitudes, thereby simulating generator voltages of different frequencies and amplitudes to provide generator voltages of different frequencies and amplitudes to the grid side of converter 21. The second filter unit 121 can filter the generator voltages of different frequencies and amplitudes converted by the second auxiliary converter 121 to filter out unacceptable voltage harmonics mixed in the generator voltage, so as to ensure that the harmonics of the generator voltage input to converter 21 meet the operating requirements of converter 21.
[0050] Based on the above embodiments, optionally, the second test converter 121 includes a second AC-DC-AC converter 1211;
[0051] The first input / output terminal of the second AC-DC-AC converter 1211 serves as the grid-side terminal of the second auxiliary converter 121, and the second input / output terminal of the second AC-DC-AC converter 1211 serves as the machine-side terminal of the second auxiliary converter 121.
[0052] The second AC-DC-AC converter can collect the second current output from the machine side of the converter 21. When the second AC-DC-AC converter detects that the second current exceeds the set current threshold (the maximum current that the power devices of the AC-DC-AC converter can withstand), it will stop operating, thereby quickly cutting off the power input circuit of the power frequency grid 20, thereby reducing the short-circuit current that the power circuit of the converter is subjected to and preventing the failure range of the devices from expanding.
[0053] Optionally, based on the above embodiments, the second filtering unit 121 includes a second LCL-type filter; the first end of the second LCL-type filter serves as the first end of the second filtering unit 121, and the second end of the second LCL-type filter serves as the second end of the second filtering unit 121.
[0054] Optionally, based on the above embodiments, the power circulation module 130 includes a power circulation transformer;
[0055] The first end of the power circulation transformer serves as the first end of the power circulation module 130, and the second end of the power circulation transformer serves as the second end of the power circulation module 130.
[0056] Among them, the power circulating transformer can isolate the current loop between the power frequency grid 20 and the grid voltage simulation module 110 and the motor voltage simulation module 120, based on the energy interaction between the power frequency grid 20 and the grid voltage simulation module 110 and the motor voltage simulation module 120.
[0057] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this disclosure can be achieved, and this is not limited herein.
[0058] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.
Claims
1. A converter testing device, characterized in that, This includes a power grid voltage simulation module, a motor voltage simulation module, and a power cycling module; The first end of the power circulation module and the first end of the power grid voltage simulation module are both connected to the power frequency grid. The first end of the motor voltage simulation module is connected to the second end of the power circulation module. The power circulation module is used to isolate the current loop between the power frequency grid and the power grid voltage simulation module and the motor voltage simulation module. The second end of the grid voltage simulation module is used to connect to the grid side of the converter, and the second end of the motor voltage simulation module is used to connect to the generator side of the converter. The grid voltage simulation module is used to simulate grid voltages of different frequencies and amplitudes, and the motor voltage simulation module is used to simulate generator voltages of different frequencies and amplitudes, so that the grid side and generator side of the converter can be tested under AC voltages of different frequencies and amplitudes.
2. The converter testing device according to claim 1, characterized in that, The power grid voltage simulation module includes a first test converter and a first filter unit; The grid-side terminal of the first auxiliary converter serves as the first terminal of the grid voltage simulation module, the machine-side terminal of the first auxiliary converter is connected to the first terminal of the first filter unit, and the second terminal of the first filter unit serves as the second terminal of the grid voltage simulation module.
3. The converter testing device according to claim 2, characterized in that, The first auxiliary converter includes a first AC-DC-AC converter; the first input / output terminal of the first AC-DC-AC converter serves as the grid-side terminal of the first auxiliary converter, and the second input / output terminal of the first AC-DC-AC converter serves as the machine-side terminal of the first auxiliary converter.
4. The converter testing device according to claim 2, characterized in that, The first filtering unit includes a first LCL type filter; The first end of the first LCL filter serves as the first end of the first filtering unit, and the second end of the first LCL filter serves as the second end of the first filtering unit.
5. The converter testing device according to claim 1, characterized in that, The motor voltage simulation module includes a second test converter and a second filter unit. The first end of the second filter unit serves as the second end of the motor voltage simulation module. The second end of the second filter unit is connected to the machine side end of the second auxiliary converter. The grid side end of the second auxiliary converter serves as the first end of the motor voltage simulation module.
6. The converter testing apparatus according to claim 5, characterized in that, The second auxiliary converter includes a second AC-DC-AC converter; the first input / output terminal of the second AC-DC-AC converter serves as the grid-side terminal of the second auxiliary converter, and the second input / output terminal of the second AC-DC-AC converter serves as the machine-side terminal of the second auxiliary converter.
7. The converter testing apparatus according to claim 5, characterized in that, The second filtering unit includes a second LCL-type filter; The first end of the second LCL filter serves as the first end of the second filtering unit, and the second end of the second LCL filter serves as the second end of the second filtering unit.
8. The converter testing apparatus according to claim 1, characterized in that, The power circulation module includes a power circulation transformer; The first end of the power circulation transformer serves as the first end of the power circulation module, and the second end of the power circulation transformer serves as the second end of the power circulation module.