Patent ID: 8384335

Claim:
A motor driving apparatus comprising: an AC/DC converter which converts an AC voltage supplied from a power source into a DC voltage through PWM switching control of a power device; and a DC/AC converter which converts said DC voltage into a variable-frequency AC voltage for driving a motor in a controlled manner, and wherein said AC/DC converter includes: a control unit which generates, based on an error between said DC voltage and a DC voltage command value, a PWM signal for the PWM switching control of said power device; and a frequency/gain varying unit which sets the frequency of said PWM signal to be generated by said control unit and a control gain in said control unit higher than normal levels during a period that a load for said DC/AC converter varies, wherein said frequency/gain varying unit sets said frequency and said gain higher than said normal levels prior to starting acceleration or deceleration of said motor whose driving is controlled by said DC/AC converter, and sets said frequency and said gain back to said normal levels upon completion of said acceleration or deceleration.