Patent ID: 8410744

Claim:
A motor driving apparatus comprising: a PWM converter which, under PWM control, converts AC power supplied from a power source into DC power and vice versa; a PWM inverter which converts the DC power output from said PWM converter into variable-frequency AC power and vice versa, and which drives a motor with said variable-frequency AC power; a power storage device, provided between said PWM converter and said PWM inverter, that can store electric power in an amount capable of driving said motor; and a control circuit which turns on and off said PWM control in said PWM converter, and wherein the voltage of said power storage device is controlled by said PWM converter to a voltage higher than a supply voltage during the period that said PWM control is turned on by said control circuit, and power less than the power required by said motor during an acceleration control period is supplied, and at least a portion of a regenerative power occurring in said motor during a deceleration control period is recovered by said power storage device when said control circuit turns off said PWM control from the time a current or power supplied from said power source has exceeded a predetermined limit value during said acceleration control period of said motor until said deceleration control period ends.