GB/T 25389.2-2018Wind turbines—Permanent magnet synchronous generator—Part 2: Testing methods (English PDF)

4.1 Safety measures

Since the test process involves dangerous currents, voltages, magnetic fields and mechanical forces, safety precautions shall be taken for all tests; and all tests shall be performed by professionals with relevant qualifications.

4.2 Instruments and meters for measurement

The instruments and meters for measurement shall meet the following requirements. […]

4.3 Preparation for test

Before the test, the generator under test shall be in a normal state; the wiring shall be correct; and the test circuit and equipment shall meet the requirements of the test.

5.1 Determination of insulation resistance

5.1.1 Determination of insulation resistance of winding against casing, and between windings

5.1.1.3 Measurement method

The measurement of the insulation resistance of the winding against the casing shall be carried out in accordance with the provisions of GB/T 1029. The insulation resistance of the stator winding and components shall be measured separately. Before the measurement, the external components shall be reliably disconnected to avoid damage.

5.1.2 Determination of other insulation resistance

The methods for measuring other insulation resistances are as follows. […]

5.2 Measurement of DC resistance of winding in actual cold state

5.3 Interturn withstand voltage test

The interturn withstand voltage test shall be carried out according to the methods specified in GB/T 22715, GB/T 22719.1 and GB/T 22719.2.

5.4 Voltage withstand test

5.4.1 Test requirements

The withstand voltage test is carried out when the generator is at rest. Before the test, the insulation resistance of the winding shall be measured. If overspeed and short-time overcurrent tests are required, the test shall be performed after these tests. During the type test, the withstand voltage test shall be carried out after the heat test and when the generator is close to the hot state.

5.4.2 Test method

The withstand voltage test shall be carried out according to the method specified in GB/T 1029.

Other windings and embedded temperature detection components not participating in the test shall be electrically connected to the iron core or the casing, and the casing shall be grounded.

If the neutral point of the winding is not easy to separate, the voltage shall be applied to the winding at the same time.

5.5 Phase sequence check

5.5.1 Generator method

The motor under test operates as a generator, and the direction of rotation complies with the design provisions. The motor line under test is connected to the phase sequence indicator to determine the phase sequence of the motor under test.

5.5.2 Motor method

Use the calibrated power supply to drive the tested motor for motor operation, and the direction of rotation shall comply with the design provisions.

5.9 No-load test

5.9.1 Determination of no-load characteristic curves of generators in cold state and hot state (generator method)

5.10.5 Measurement of cooling medium temperature during heat test

5.10.5.1 Air-cooled motors

For motors cooled by ambient air, the embedded temperature detectors or several thermometers distributed in the cooling air to enter the generator can be used for measurement. The thermometer shall be placed 1m~2m away from the generator, and its spherical part (temperature measuring part) shall be on the horizontal plane above the center of the generator shaft; and shall prevent the influence of external radiation heat source and airflow, and take the average value of the temperature value as the cooling medium temperature.

5.18 Determination of starting resistance torque

5.18.1 Disk method

A disc with a known diameter is fixedly installed on the shaft extension of the generator; and a force is applied in the tangential direction of the disc. The value of the applied force when the disc starts to rotate is measured by a torque sensor. When the disc is rotated for one circle, the product of the maximum reading and the disc radii is the starting resistance torque. There shall be no less than 3 measuring points within a week.

5.18.2 Leverage method

A torque lever is fixedly installed in the vertical direction of the shaft extension of the generator.

The end of the lever is connected to a crane connected to a dynamometer or a spring balance.

Apply force in the tangential direction until the shaft extension starts to rotate; and read the value of the applied force when it starts to rotate. The product of the maximum reading and the effective length of the lever is the starting resistance torque.

5.19 Casing protection level test

The casing protection level test shall be carried out according to the test method specified in GB/T 4942.1.

5.20 Damp heat test

The damp heat test shall be carried out according to the test method specified in GB/T 12665.

5.21 Salt spray test

The salt spray test shall be carried out according to the test method specified in GB/T 2423.17.

5.22 Mold test

The mold test shall be carried out according to the test method specified in GB/T 2423.16.

A.1 Test purpose

Measure the relationship curve between permanent magnet and temperature.

A.2 Test method

The generator is driven by the tractor through the coupling to run at no-load and at the rated speed, and the stator winding is open-circuited. Simulate the winding temperature theta from the cold state of the generator to the stable state of temperature-rise; the temperature is no less than 5 points, including the reference temperature. Use a voltage measuring instrument to measure the m-phase voltage U at the output terminal of the generator; and draw the no-load voltage curve of the generator at different winding temperatures (see Figure A.1). […]