PMSM stator winding resistor asymmetric fault diagnosis method

Abstract

The invention discloses a PMSM stator winding resistor asymmetric fault diagnosis method comprising the following steps: firstly injecting a DC signal into a linkage control loop in a PMSM direct torque control system, thus forming dc components in the three-phase stator winding current; secondly, measuring the three-phase stator winding current and zero sequence voltage and calculating the mean value thereof, and using the obtained three-phase stator winding current and zero sequence voltage mean value to estimate a three-phase stator winding resistor offset amount; finally, using the three-phase stator winding resistor offset amount to diagnose and position stator winding resistor asymmetric faults. The method is small in computational complexity, simple in operation, high in reliability, can accurately diagnose the PMSM stator winding resistor asymmetric faults, can position a fault phase, can reflect the fault level, and is not affected by the stator winding turn-to-turn short circuit fault.

Description

technical field [0001] The invention relates to the technical field of fault diagnosis, in particular to a method for diagnosing the asymmetrical fault of the stator winding resistance of a permanent magnet synchronous motor. Background technique [0002] Permanent magnet synchronous machine (PMSM) is an environmentally friendly and low-carbon motor with high efficiency, high moment-to-inertia ratio, and high energy density. In recent years, it has been widely concerned and used in electric vehicles and wind power generation. [0003] The permanent magnet synchronous motor itself is an electromechanical coupling system. It usually works in a small space, high temperature, vibration and other harsh environmental conditions. Subject. Due to the complex operating conditions of permanent magnet synchronous motors, narrow installation space and poor heat dissipation environment, the probability of failure of permanent magnet synchronous motors is high. According to the compone...

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Problems solved by technology

When the fault occurs initially, the motor can continue to run, but if it runs for a long time under the fault condition, it will cause a series of other types of motor faults. When the fault is aggravated, the motor will be forced to stop, and even cause irreversible damage.

At present, some methods have been proposed to diagnose the asymmetric fault of the stator winding resistance of the permanent magnet synchronous motor, but there are still some deficiencies in the existing diagnostic methods and technologies, such as diagnosing the asymmetric fault of the stator winding resistance according to the relationship between the stator current and the zero-sequence voltage The method is affected by the inter-turn short circuit fault of the stator winding, which leads to the low reliability of this fault diagnosis technique.

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