Current sensor fault diagnosis method, device and frequency converter for synchronous motor

Abstract

The invention provides a synchronous motor current sensor fault diagnosis method and device and a frequency converter. The synchronous motor current sensor fault diagnosis method comprises the following steps: obtaining a sampling value of current of a synchronous motor; establishing a Lenberg observer model according to a current state equation of the synchronous motor, and obtaining an observed value of the current through a Lenberg observer; and when the deviation of the observed value and the sampling value exceeds a preset difference threshold value, judging that the current sensor has fault. According to the technical scheme, the synchronous motor current sensor fault diagnosis method and device can judge the fault of the current sensor timely and accurately, facilitate workers to carry out trouble removal and improve system operation reliability.

Description

technical field

[0001] The invention relates to the technical field of motors, in particular to a current sensor fault diagnosis method, device and frequency converter for synchronous motors. Background technique

[0002] When the frequency converter adopts vector control, it usually needs to use the current sensor. Sensors are very precise and susceptible to interference. In the factory environment, due to factors such as noise, vibration, surge voltage and inrush current, the performance of the sensor will degrade, malfunction and fail, and then affect the normal operation of the system. According to statistics, in the automation system, the number of false alarms due to sensor failure accounts for about half of the total failure. It can be seen that it is very necessary to diagnose the fault of the sensor. However, in the prior art, it is not easy to detect the failure of the current sensor, and it is also difficult for the staff to troubleshoot, resulting in poor relia...

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