Online monitoring method and system for motor on the basis of instantaneous three-phase voltage and current unbalance degree

Abstract

The invention discloses an online monitoring method for motor on the basis of an instantaneous three-phase voltage and current unbalance degree. The online monitoring method comprises the following steps that: collecting the three-phase voltage and the three-phase current of a three-phase alternating current motor to obtain the original three-phase voltage signal and the original three-phase current signal of the three-phase alternating current motor; establishing a band-pass filter which takes fundamental frequency as the center to carry out filtering processing on the original three-phase voltage signal and the original three-phase current signal to obtain the filtered three-phase voltage signal and three-phase current signal; independently obtaining an instantaneous three-phase voltageunbalance degree and an instantaneous three-phase current unbalance degree unbalance degree; and independently comparing the instantaneous three-phase voltage unbalance degree and the instantaneous three-phase current unbalance degree with a corresponding threshold value to obtain a comparison result, and on the basis of the comparison result, judging whether an alarm motion is triggered or not. By use of the online monitoring method, on the basis of the instantaneous three-phase voltage unbalance degree and the instantaneous three-phase current unbalance degree, a motor insulation state is evaluated in real time so as to realize online monitoring. A three-phase voltage and current signal is high in data resolving power, and a status alarm which has higher accuracy than an alarm strategy based on temperatures can be realized.

Description

technical field [0001] The invention relates to the technical field of on-line motor monitoring, in particular to an on-line motor monitoring method and system based on instantaneous three-phase voltage and current unbalance. Background technique [0002] The reliability and life of motor operation are largely determined by its insulation performance. Therefore, the development of insulation state assessment technology to accurately evaluate the health status of traction motor insulation will help improve the safety of motor operation, reduce the risk of train operation, and reduce Reduce maintenance costs and improve maintenance efficiency. [0003] The motor insulation state evaluation technology is divided into offline detection technology and online monitoring technology. The off-line detection technology has developed maturely, and related detection products such as insulation resistance and capacitance test equipment have been very mature, and are widely used in motor...

AI Technical Summary

Problems solved by technology

Although the current online monitoring technology for motor insulation based on temperature is low in cost and high in cost performance, it has a high rate of false alarms and poor timeliness, which can no longer meet the current monitoring requirements for important motors with high real-time, high precision and high accuracy.

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