Patent ID: 9698721
Date: 2017-07-04
CPC Classifications: H02M,H02P,Y02B,Y02P

Claim:
1. An AC motor driving method, comprising: rectifying a mains supply to a first DC voltage via a three-phase full-wave rectifier circuit; supplying the first DC voltage to a step-up/step-down circuit and a voltage controller, wherein the step-up/step-down circuit is controlled by the voltage controller to generate a second DC voltage having a semi-sinusoidal waveform; supplying the second DC voltage to the voltage controller; generating an electrical angle by an AC motor controller, wherein the electrical angle is supplied to a voltage command generator; generating a voltage command by the voltage command generator, and supplying the voltage command to the voltage controller; and comparing the second DC voltage with the voltage command by the voltage controller, wherein if the second DC voltage and the voltage command are different, the voltage controller generates a plurality of signals to drive the step-up/step-down circuit for adjusting the second DC voltage to approach the voltage command; wherein the step-up/step-down circuit comprises a first power transistor and a second power transistor; when the voltage command is greater than or equal to the first DC voltage, the step-up/step-down circuit is operated in a step-up mode, the first power transistor is turned on, and the second power transistor is controlled to perform a pulse width modulation for adjusting the second DC voltage to approach the voltage command in accordance with a compensation result calculated by the voltage controller; when the voltage command is less than the first DC voltage, the step-up/step-down circuit is operated in a step-down mode, the second power transistor is turned off, and the first power transistor is controlled to perform a pulse width modulation for adjusting the second DC voltage to approach the voltage command in accordance with the compensation result calculated by the voltage controller.