Single-current-sensor-based current loop control method and apparatus of moto

Abstract

The invention discloses a single-current-sensor-based current loop control method and apparatus of a motor. The single-current sensor is used for detecting a current of a direct-current bus. The method comprises: a starting time of a current PWM half cycle is detected, and a first AD sampling trigger time and a second AD sampling trigger time of the current PWM half cycle are obtained when the starting time of the current PWM half cycle is detected; according to the first AD sampling trigger time and the second AD sampling trigger time, a first direct-current bus sampling current and a second direct-current bus sampling current are sampled correspondingly; and after completion of second-time sampling, a three-phase PWM waveform is outputted based on the first direct-current bus sampling current and the second direct-current bus sampling current to carry out current loop controlling on a motor, and a PWM phase-shift parameter of a next PWM half cycle, a first AD sampling trigger time, and a second AD sampling trigger time are generated according to the outputted three-phase PWM waveform. Therefore, the delay of the current loop can be reduced to be within a half PWM cycle and thus the current loop delay time is shortened.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a current loop control method for a motor based on a single current sensor and a current loop control device for a motor based on a single current sensor. Background technique [0002] In recent years, commonly used motors, including induction motors, permanent magnet synchronous motors, and brushless DC motors, mostly use vector control methods to improve control performance. In the related art, the current closed-loop control of the motor vector control is generally performed once every or multiple PWM (pulse-width modulation) cycles, that is, the output voltage is calculated according to the feedback current and 6 PWM driving signals are output through the SVM technology. However, the disadvantage of the related control method is that when the carrier frequency is low, the lag of the current loop will be too large, resulting in a low bandwidth of the current loop, which ...

AI Technical Summary

Problems solved by technology

However, the disadvantage of the related control method is that when the carrier frequency is low, the lag of the current loop will be too large, resulting in a low bandwidth of the current loop and affecting the adjustment performance of the speed loop.

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