Default phase detection method and device for motor

Abstract

The invention discloses a default phase detection method for a motor. The method includes the following steps that when the phase current of the motor is zero, a first current variable and a first digital variable which correspond to a current digital quantity D<0> are acquired; through controlling the d-axis preset current shown in the specification, of the motor, a minimal phase current peak value in the motor operating process is the first current variable; a phase current digital quantity D of the motor is detected in real time, and an absolute value of the phase current digital amount D is compared with the first digital variable; if the absolute value of the phase current digital quantity D is smaller than the first digital variable and duration is larger than a time threshold value T<D0>, it is judged that the motor is in a default phase state. The default phase detection method for the motor can detect whether the motor is in the default phase state or not before the motor is operated and when the motor is operated in real time and can accurately detect whether any phase of the motor is a default phase or not; compared with a control method making the d-axis current be zero, the output torque performance of a salient pole of the motor can be improved, and the output torque performance of a non-salient pole of the motor is not affected. The invention further discloses a default phase detection device for the motor.

Description

technical field [0001] The invention relates to the technical field of motors, in particular to a motor phase loss detection method and a motor phase loss detection device. Background technique [0002] When the motor controller is used to detect the phase current of the motor, the phase current signal of the collected motor is generally converted into a voltage analog signal through the current-voltage conversion module, and then the voltage analog signal is converted into a digital quantity through the analog-to-digital conversion module , and finally the program in the motor controller controls the motor through digital quantities. [0003] When the motor controller is used to detect the lack of phase of the motor, the motor controller collects the phase current of the motor in real time, and compares the converted phase current digital quantity with the converted phase current digital quantity when the motor is no-load. If the final phase current digital value is less t...

AI Technical Summary

Problems solved by technology

However, due to the noise interference of the voltage analog signal and the resolution problem of the analog-to-digital conversion module, the converted digital quantity superimposes the amount of noise, resulting in misjudgment of motor phase loss, especially for controlling the d-axis current to be zero (I d =0) for the permanent magnet motor, in the motor deceleration process, when the required torque to maintain the command deceleration is equal to the load torque, the output torque of the motor is zero, and now the q-axis current is zero (I q =0), while the d-axis current is also zero (I d =0), that is, the phase current of the motor is zero, which will lead to misjudgment of phase loss

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