The stator of a motor is the stationary part of the motor. The stator is mainly composed of the stator core, winding, and machine base. The testing items for AC motor stator and DC motor stator are partially different. Below are the stator testing items:
1、 Test items for stator of AC motor
1. AC withstand voltage: Test the ability of stator insulation to withstand power frequency voltage, and detect whether the stator will experience breakdown or surface flashover;
2. Insulation resistance: Apply a certain value of DC voltage between the stator winding and the iron core, measure its insulation resistance value, and detect whether there is leakage or short circuit between the coil and the iron core.
3. Inter turn withstand voltage: Apply continuous inter turn pulses at the beginning and end of each winding or between phases to test for insulation defects or short circuits between the inner turns or between the windings of each phase. At the same time, it can detect whether the number of coil turns is within the qualified range, whether there are coil unit reverse embedding and wiring errors, etc.:
4. DC resistance: Test the DC resistance value of each phase coil, which can detect whether the wire diameter and number of coils are incorrect, whether there is a short circuit, and other problems;
5. Inter phase insulation: Testing the insulation between phase windings and the insulation of the entire winding to iron can identify defective windings;
6. Steering test: The steering can be determined based on the test waveform;
8. Magnetic pole test: It can perform stator magnetic pole testing on special AC motors such as pole setting motors and series excited motors.
2、 DC motor stator testing items
1. Inductance test: Setting the test frequency and level can test the true inductance value of the stator under working conditions. Virtual values can also be derived by inverting the high-frequency components of the inter turn waveform;
2. Hall test: Rotate a magnet around a motor to sense the Hall element, and evaluate the high and low levels, frequency, and other parameters of the Hall element to evaluate the quality of the product;
3. Reverse electromotive force test: When the magnetic field changes, the line coil will generate induced electromotive force. Under normal circumstances, the waveform can be observed with an oscilloscope, and the reverse electromotive force constant can be calculated through voltage and speed to meet the requirements. The Aipu tester can convert Hall and reverse electromotive force data, without the need for manual judgment of the waveform. Only the upper and lower limits need to be set, and an automatic unqualified alarm can be triggered, reducing the manual skill requirements.
