Patent ID: 7495410

Claim:
A motor drive system, comprising: a switching rectifier including a first set of switching devices coupled with an AC input and operable according to a first set of switch control signals to selectively couple the AC input with an intermediate DC link to provide a DC link current; an inverter including a second set of switching devices coupled with the DC link and operable according to a second set of switch control signals to provide an AC output current to a motor; and a controller operatively coupled with the switching rectifier and with the inverter to provide the first and second sets of switch control signals, the controller comprising: a motor control component determining a required motor control current value according to motor feedback and a setpoint or profile, a power factor control component determining a required power factor compensation current value corresponding to input capacitors associated with the AC input, a rectifier control component operative to provide the first set of switch control signals to the switching rectifier to provide an increased DC link current over at least a portion of a motor speed range according to the required motor control current value and the required power factor compensation current value to control the power factor of the motor drive system, and an inverter control component operative to provide the second set of switch control signals to the inverter to provide the AC output according to the required motor control current.