A Fault Diagnosis Method for Turn-to-turn Short Circuit of Permanent Magnet Synchronous Motor Based on Flux Linkage Observation

Abstract

The invention discloses a permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis method based on flux linkage observation, and the method comprises the following steps: S1, estimating three-phase voltages (shown in the description) of a permanent magnet synchronous motor through employing a flux linkage observer of a current model; S2, comparing the three-phase voltages (shown in the description) obtained at step S1 and reference values (shown in the description) of the three-phase voltage, and obtaining the deviations delta ua, delta ub and delta uc of the three-phase voltages; S3, judging whether there is a turn-to-turn short circuit fault or not, and defining FI=<|delta ua|+|delta ub|+|delta uc|>: judging that there is a stator winding turn-to-turn short circuit fault if the FI is greater than thr, or else, judging that there is no stator winding turn-to-turn short circuit fault, wherein FI is a fault characteristic value, <> represents a mean value, and thr is a threshold value.

Description

technical field [0001] The invention relates to the technical field of fault diagnosis, in particular to a method for diagnosing a short-circuit fault between turns of a permanent magnet synchronous motor based on flux linkage observation. Background technique [0002] Permanent magnet synchronous machine (Permanent magnet synchronous machine, PMSM) has the advantages of high power density, high efficiency, large torque inertia ratio, and wide speed range. In recent years, it has been widely concerned and used in electric vehicles and wind power generation. [0003] Permanent magnet synchronous motor is composed of electrical system and mechanical system such as stator, rotor and bearing. When the motor is working, it has a complex electromechanical energy conversion process. In the long-term operation, affected by the power supply, load conditions and operating environment, some components will gradually fail or be damaged. Common failure modes are excessive motor vibrati...

AI Technical Summary

Problems solved by technology

Among the stator winding faults, the turn-to-turn short-circuit fault of the stator winding is the most common. A large amount of eddy current will be generated in the short-circuit circuit if the turn-to-turn short circuit of the stator winding of the motor occurs. If this fault is not detected, the fault will be aggravated and will Cause ground short circuit or short circuit between phases, so that the temperature of the motor continues to increase, and finally lead to complete damage to the motor, so it is necessary to diagnose the inter-turn short circuit fault of the permanent magnet synchronous motor in time

At present, the most commonly used methods are analysis methods based on current, voltage, and vibration signals. The signal analysis techniques used include fast Fourier transform, short-time Fourier transform, Wigner-Ville distribution, wavelet transform, and empirical mode decomposition. and order ratio analysis, etc.; these signal analysis techniques require a relatively large amount of calculation, and it is difficult to realize online fault diagnosis

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