Method for diagnosing demagnetization fault of permanent-magnet synchronous motor

Abstract

The invention, which belongs to the technical field of motor fault diagnosis, discloses a method for diagnosing a demagnetization fault of a permanent-magnet synchronous motor. The method comprises the following steps: carrying out current signal sampling; calculating an instantaneous value; calculating an absolute value; automatically locating a fault phase; determining a characteristic frequencyof a demagnetization fault; determining demagnetization fault occurrence; determining a severity degree of a fault; establishing a fault model for analysis; and perfecting a solution. According to the intelligent fault diagnosis method for a permanent magnet synchronous motor, no extra equipment is needed, so that the cost is reduced; the computing is done simply; the inter-turn short circuit fault can be diagnosed in real time and the fault phase can be located automatically; defects of the existing diagnosis method can be overcome and the real-time performance, effectiveness and reliabilityof the diagnosis are enhanced; the sampling time is short; the anti-interference ability is powerful; and the demagnetization fault of the permanent-magnet synchronous motor at different rotating speeds under different loads can be determined.

Description

technical field [0001] The invention belongs to the technical field of motor fault diagnosis, and in particular relates to a method for diagnosing a demagnetization fault of a permanent magnet synchronous motor. Background technique [0002] The permanent magnet synchronous motor used for driving electric vehicles is a new type of motor. Its operating environment is complex (such as vibration, high and low temperature, humidity, dust, etc.), frequent starting, acceleration, deceleration, braking, etc., which are not conducive to the safe operation of the motor , may induce engine failure. Permanent magnet synchronous motors used in electric vehicles mostly use frequency converters as drive power sources to achieve energy saving and increase the range of motor speed variation. The magnetomotive force will have a large demagnetization effect on the permanent magnet; in order to obtain a sinusoidal air gap flux density waveform, the permanent magnet should be chamfered when de...

AI Technical Summary

Problems solved by technology

[0003] To sum up, the problems existing in the existing technology are: the current motor fault analysis needs to add additional equipment, the cost is high, the calculation is simple and complicated, and the diagnosis is inaccurate; at the same time, it is difficult to diagnose under different speeds and different loads

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