GB/T 25387.2-2021Wind turbines generator system—Full-power converter—Part 2:Test method (English PDF)

3.1 Test environment conditions

The test conditions of the converter are as follows.

a) Temperature. 15°C~35°C;

b) Relative humidity. 45%~75%;

c) Air pressure. 86kPa~106kPa; d) Altitude. <=2000m.

3.2 Measuring instruments

Measuring instruments and meters should meet the following requirements.

a) Instrument and meter verification. The measuring instruments, meters, and sensors used in the test should be verified by the metrological department and within the validity period. And meet the accuracy requirements within the sampling frequency range;

b) Instrumentation requirements. The accuracy of the electrical measuring instruments used in the test should not be less than 0.5 (except for megohmmeters), current mutual inductance The accuracy of the sensor should not be less than 0.2, the accuracy of the power transmitter should not be less than 0.5, and the error of the thermometer should not be greater than ±1°C, the accuracy of other non-electrical measuring instruments is equivalent to class 1.0 and should comply with relevant standards. If the product The test requires a higher level of test instruments, which should be clearly stipulated in the product technical agreement.

4.1 Test platform

The converter test should be carried out under electrical conditions equivalent to actual work, as much as possible to simulate wind farm conditions. For example, the test platform can be The motive-generator drive unit is composed to simulate the power characteristics of the wind generator. The drive unit consists of a motor and a motor-side adaptive transformer Converters, motor drive converters, generators, generator-side adapter transformers, converters under test, consoles, power grid simulators and related power distribution equipment Considering that some grid adaptability tests are required for the converter, this part of the test cannot affect the control of the drag motor, so it is The external power grid of the measuring converter should be decoupled from the external power grid of the drive motor. The recommended test platform is shown in Appendix A.

4.2 Test items and content

4.2.1 Electrical safety test

4.2.1.1 Insulation strength measurement test

Short-circuit the input and output ports on the main circuit, the main contacts of the switch and the contactor, and the anode and cathode terminals on the semiconductor device, and disconnect the protection Mine, grounding cable. The input circuit of the converter is to the ground and the output circuit is to the ground, and the test shall be carried out in accordance with the provisions of GB/T 25387.1. Type test The duration of the test voltage in the test shall not be less than 1min, and the duration of the test voltage in the factory test shall not be less than 1s. Test voltage can be increased (Or drop) the ramp voltage, but it should be maintained at its full value for the specified duration.

4.2.1.2 Insulation resistance measurement test

One minute after the completion of the dielectric strength test, a 1000V DC voltage should be applied for testing in accordance with the technical requirements in GB/T 25387.1.

If liquid is used as the cooling medium, the water circuit should be maintained in a normal state and its insulation resistance should be measured.

4.2.1.3 Grounding resistance measurement test

The tested converter needs to disconnect all external terminals, including the ground terminal. The test point is the ground terminal of the measured converter and the measured converter Any contactable conductor position shall be judged in accordance with the technical requirements of GB/T 25387.1.

4.2.1.4 Capacitor discharge time test

After the converter stops and the main circuit breaker is disconnected, measure the time it takes for the voltage of the capacitor inside the converter to drop to 60V.

4.2.2 Loading test

The type test needs to be tested and verified according to the following steps, and the factory test can be adjusted according to the actual situation.

The test is carried out on the simulated test platform recommended in Appendix A, and the steps are as follows. The provisions of 7.4.2 in GB/T 3859.1-2013 shall be implemented.

The test should be carried out under the specified rated current operating conditions and the most unfavorable cooling conditions. The temperature measuring element should adopt the temperature during the test Meter, thermocouple, thermal element, infrared thermometer or other effective methods.

For semiconductor devices of the main circuit, the measurement should include the devices with the worst cooling conditions, and record the temperature rise and meter of the specified parts of the semiconductor device.

Calculate the equivalent junction temperature. The temperature rise limit of a semiconductor device can be the highest temperature rise at a specified point (such as the case) or the equivalent junction temperature. The factory decides.

4.2.20 Protection function test

4.2.20.1 Type 1 fault protection

4.2.20.1.1 Grid power failure protection

Refer to the test platform in Appendix A, turn on the main power of the system, and start the grid-connected operation of the converter.

Disconnect the simulated power grid, the tested converter should be able to stop immediately. After the shutdown is completed, the converter should be able to report the correct fault information without any responsibility.

What is abnormal. After the fault is eliminated and reset, the normal grid-connected state can be restored.

4.2.20.1.2 Short-circuit protection to ground

Refer to the test platform in Appendix A. Under the shutdown state, the hardware protection threshold is modified to lower the short-circuit hardware protection threshold. Value threshold.

Start the converter to complete the grid connection, and adjust the AC terminal current of the grid-side converter and the machine-side converter respectively, so that the operating current triggers the short-circuit protection threshold Value, the tested converter should be able to stop immediately. After the shutdown is completed, the converter should be able to report the correct fault information without any abnormalities. Fault elimination After removing and resetting, the normal grid-connected state can be restored.

Refer to the test platform in Appendix A, start the converter to complete the grid connection, and simulate the feedback signal inversion method of the protection device, and the tested transformer The flow device should be able to stop immediately. After the shutdown is completed, the converter should be able to report the correct fault information without any abnormalities. The fault is cleared and reset After that, the normal grid-connected state can be restored.

4.2.20.1.3 Phase loss protection

Refer to the test platform in Appendix A, and disconnect one of the phase wires of the AC terminal on the grid side and the machine side in the shutdown state.

When the main power of the system is connected, the converter should be able to report correct fault information, and it is forbidden to start the machine without any abnormality. After the fault is eliminated and reset, it can be restored Return to the normal grid-connected state.

4.2.20.1.4 Phase sequence error protection

Refer to the test platform in Appendix A, and switch the two-phase cable on the grid side or the machine side when the power is off.

When the main power of the system is connected, the converter should be able to report correct fault information, and it is forbidden to start the machine without any abnormality. After the fault is eliminated and reset, it can be restored Return to the normal grid-connected state.

4.2.20.1.5 Instantaneous overcurrent protection test

Refer to the test platform in Appendix A. Under the shutdown state, the hardware protection threshold can be modified to reduce the instantaneous overcurrent hardware Protection threshold threshold.

Start the converter to complete the grid connection, and adjust the AC terminal current of the grid-side converter and the machine-side converter respectively, so that the working current triggers an instantaneous overcurrent For the protection threshold, the tested converter should be able to stop immediately. After the shutdown is completed, the converter should be able to report the correct fault information without any abnormality.

After the fault is eliminated and reset, the normal grid-connected state can be restored.

4.2.20.1.6 DC overvoltage protection

Refer to the test platform in Appendix A. Under the shutdown state, the hardware protection threshold can be modified to reduce the DC overvoltage hardware protection. Protection threshold threshold.

Start the converter to complete the grid connection, so that the DC bus voltage is higher than the threshold threshold, triggering a DC overvoltage fault, and the tested converter should be able to immediately Downtime. After the shutdown is completed, the converter should be able to report the correct fault information without any abnormality. After the fault is eliminated and reset, it can return to normal Grid-connected status.

4.2.20.1.7 DC undervoltage protection

Refer to the test platform in Appendix A. In the shutdown state, the hardware protection threshold can be modified to increase the DC undervoltage hardware protection. Protection threshold threshold.

Start the converter to complete the grid connection, so that the DC bus voltage is lower than the threshold threshold, triggering a DC undervoltage fault, and the tested converter should be able to immediately Downtime. After the shutdown is completed, the converter should be able to report the correct fault information without any abnormality. After the fault is eliminated and reset, it can return to normal Grid-connected status.

4.2.20.1.8 UPS output power failure protection

Refer to the test platform in Appendix A, turn on the main power of the system, and start the grid-connected operation of the converter.

After disconnecting the UPS output, the tested converter should be able to stop immediately. After the shutdown, there was no abnormality. After the fault is eliminated and reset, you can Restore the normal grid-connected state.

4.2.20.2 Type 2 fault protection

4.2.20.2.1 Voltage unbalance protection

Refer to the test platform in Appendix A, turn on the main power of the system, and start the grid-connected operation of the converter.

Adjust the output voltage of the power grid simulator so that the voltage negative sequence unbalance degree exceeds the software protection threshold, and the tested converter should be able to follow the set Slow shutdown strategy, load shedding and shutdown. After the shutdown is completed, the converter should be able to report the correct fault information without any abnormality. The fault is eliminated and restored After the position, the normal grid-connected state can be restored.

4.2.20.2.2 Power grid over-frequency protection

Refer to the test platform in Appendix A, turn on the main power of the system, and start the grid-connected operation of the converter.

Adjust the output grid frequency of the grid simulator so that the grid frequency exceeds the software protection threshold, and the tested converter should be able to slow down according to the set Machine strategy, load shedding and shutdown. After the shutdown is completed, the converter should be able to report the correct fault information without any abnormality. After the fault is eliminated and reset, It can be restored to normal grid-connected state.

4.2.20.2.3 Grid under-frequency protection

Refer to the test platform in Appendix A, turn on the main power of the system, and start the grid-connected operation of the converter.

Adjust the output grid frequency of the grid simulator so that the grid frequency is lower than the software protection threshold, and the tested converter should be able to slow down according to the set Machine strategy, load shedding and shutdown. After the shutdown is completed, the converter should be able to report the correct fault information without any abnormality. After the fault is eliminated and reset, Can be restored to normal grid-connected state.

4.2.20.2.4 Overcurrent protection

Refer to the test platform in Appendix A, under the shutdown state, by modifying the software protection threshold method, reduce the overcurrent software protection Threshold threshold.

Start the converter to complete the grid connection, and adjust the AC terminal current of the grid-side converter and the machine-side converter respectively, so that the working current triggers overcurrent protection Threshold, the tested converter should be able to reduce load and stop according to the set slow shutdown strategy. After the shutdown is completed, the converter should be able to report the correct fault message Information, and there is no abnormality. After the fault is eliminated and reset, the normal grid-connected state can be restored.

4.2.20.2.5 Generator over-speed protection

Refer to the test platform in Appendix A, turn on the main power of the system, and start the grid-connected operation of the converter.

When adjusting the generator speed to exceed the overspeed protection threshold, the tested converter should be able to reduce load and stop according to the set slow shutdown strategy. Shutdown After completion, the converter should be able to report correct fault information without any abnormalities. After the fault is eliminated and reset, the normal grid-connected state can be restored.

4.2.20.2.6 Communication fault protection

Refer to the test platform in Appendix A, connect the main power of the system, and start the grid-connected operation of the converter by simulating the main control.

Disconnect the communication between the tested converter and the analog main control. The tested converter should be able to reduce load and stop according to the set slow shutdown strategy. Shutdown is complete After that, the converter should be able to report the correct fault information without any abnormality. After the fault is eliminated and reset, the normal grid-connected state can be restored.

4.2.20.2.7 Cooling system failure protection

Refer to the test platform in Appendix A, turn on the main power of the system, and start the grid-connected operation of the converter.

Stop the cooling system operation of the tested converter, the tested converter should be able to reduce load and stop according to the set slow shutdown strategy. Shutdown complete After that, the converter should be able to report the correct fault information without any abnormality. After the fault is eliminated and reset, the normal grid-connected state can be restored.

4.2.20.2.8 Over temperature protection

Refer to the test platform in Appendix A. Under the shutdown state, the over-temperature protection threshold can be lowered by modifying the software protection threshold. Threshold.

Start the converter to complete the grid connection, so that the ambient temperature, coolant temperature, device temperature, etc. exceed the corresponding temperature protection threshold, and the tested converter It should be able to reduce load and stop according to the set slow stop strategy. After the shutdown is completed, the converter should be able to report the correct fault information without any abnormality.

After the fault is eliminated and reset, the normal grid-connected state can be restored.

4.2.20.2.9 UPS input power failure protection

Refer to the test platform in Appendix A, turn on the main power of the system, and start the grid-connected operation of the converter.

Disconnect the UPS front stage air switch to simulate the UPS front stage power failure. The tested converter should be able to reduce load and stop according to the set slow shutdown strategy.

After the shutdown is completed, the converter should be able to report the correct fault information without any abnormality. After the fault is eliminated and reset, normal grid connection can be restored status.

4.2.20.2.10 Surge over-voltage protection

Refer to the test platform in Appendix A to remove the surge protection device or absorption device of the tested converter, and the tested converter should be able to identify correctly And prompt an alarm.

4.2.21 Immunity test

4.2.21.1 Electrostatic discharge immunity test

The converter can be operated under light load, in accordance with the provisions of GB/T 17626.2-2018 and tested under the following conditions.

a) Test voltage. contact discharge 6kV, air discharge 8kV;

b) Test port. the whole shell;

c) The number of discharges at each sensitive point test point. 10 times for each of the positive and negative polarity, and the interval between each discharge is at least 1s;

d) Performance criterion level. Class B.

4.2.21.2 Radio frequency electromagnetic field radiation immunity test

The converter can be operated under light load, in accordance with the provisions of GB/T 17626.3-2016 and tested under the following conditions.

a) Frequency range. 80MHz~1000MHz;

b) Test field strength. 10V/m;

c) 1kHz sine wave, 80% amplitude modulation;

d) Test port. the whole shell;

e) Antenna polarization direction. horizontal and vertical direction;

f) Performance criterion level. A level.

4.2.21.3 Electric fast pulse group immunity test

The converter can be operated under light load conditions, in accordance with the provisions of GB/T 17626.4-2018 and tested under the following conditions.

a) Test voltage. ±2kV (power line), ±1kV (signal line);

b) Test port. input and output power port, signal line;

c) Repetition frequency. 5kHz/100kHz;

d) Duration. 1min;

e) Performance criterion level. Class B.

4.2.21.4 Surge voltage immunity test

The converter can be operated under light load, in accordance with the provisions of GB/T 17626.5-2019 and tested under the following conditions.

a) Test voltage. ±2kV (common mode), ±1kV (differential mode);

b) Test port. input and output power port, signal line;

c) Polarity. positive and negative;

d) Test times. 5 times for positive and negative polarity;

e) Repetition rate. once per minute;

f) Performance criterion level. Class B.

4.2.21.5 Conducted disturbance immunity test

The converter can be operated under light load, in accordance with the provisions of GB/T 17626.6-2017 and tested under the following conditions.

a) Frequency range. 0.15MHz~80MHz;

b) Test field strength. 10V (modulation);

c) 1kHz sine wave, 80% amplitude modulation;

d) Test port. external port;

e) Injection method. CDN or current clamp, electromagnetic clamp;

f) Performance criterion level. A level.

4.2.22 Electromagnetic emission test

4.2.22.1 Conducted emission test

The converter should be operated under normal full load or light load, in accordance with the provisions of GB/T 12668.3-2012 and under the following conditions test.

a) Test frequency band. 150kHz~30MHz;