Phase current reconstruction method and device

The invention discloses a three-phase current reconstruction method. The method comprises the steps of calculating a three-phase duty ratio of a current PWM period according to a three-phase current value of a previous PWM period; judging whether the current PWM period enters a non-observation area or not according to the three-phase duty ratio, and determining a non-observation phase and an observable phase; when the current PWM period enters a non-observation area, acquiring the phase current of the non-observation phase by adopting a current increment model according to the duty ratio of the current PWM period of the non-observation phase, the duty ratio of the previous PWM period, the duty ratio of the previous PWM period, the phase current of the previous PWM period and the phase current of the previous PWM period; reconstructing the phase current of the current PWM period according to the phase current of the non-observation phase and the phase current of the observable phase; the non-observation area m