Method and system for detecting phase failure of motor

Abstract

The invention provides a method and a system for detecting phase failure of a motor. The method comprises the following steps of collecting current value of each phase of the motor, and determining the maximum current value and minimum current value of the current value of each phase; judging whether the maximum current value is greater than the maximum threshold value of the preset current or not and the ratio of the maximum current value and minimum current value is greater than the specific threshold value of the preset current or not; when the maximum current value is greater than the maximum threshold value of the preset current, and the ratio of maximum current value and minimum current value is greater than the specific threshold value of the preset current, outputting a phase failure fault signal. The maximum threshold value of the preset current is greater than the maximum current value of the phase-failure phase of the motor, and is smaller than the minimum current value of each phase in the normal idle running process of the motor; the specific threshold value of the preset current is smaller than 1. The method has the advantage that the phase failure of the motor is detected when the motor works at small current.

Description

technical field [0001] The invention relates to the technical field of motor equipment fault detection, in particular to a method and system for motor phase loss detection. Background technique [0002] Motor phase loss detection is one of the necessary fault detection items for motor equipment. In the traditional phase loss detection method, by calculating the maximum value of each phase current in each detection cycle, the three maximum current values ​​obtained are divided into two phases. Calculate the absolute value after subtraction, and judge whether the motor is out of phase by judging the number of times the absolute value of the current difference is greater than the current difference threshold. [0003] After research, it is found that if the motor is under no-load or light-load conditions, the current of each phase of the motor is small, which will cause the current of each phase itself to be smaller than the current difference threshold, resulting in the failur...

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Problems solved by technology

[0003] After research, it is found that if the motor is under no-load or light-load conditions, the current of each phase of the motor is small, which will cause the current of each phase itself to be smaller than the current difference threshold, resulting in the failure to detect the lack of phase of the motor, resulting in The motor can still run, which brings serious safety hazards to the production and work process

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