Phase distortion compensating apparatus and method for reducing torque ripple in 3-phase motor

Abstract

Disclosed are a phase distortion compensating apparatus and method for reducing a torque ripple in a 3-phase motor using four switching elements, which are capable of adjusting respective switching times of phase voltages, to be supplied to the 3-phase motor by an inverter including the switching elements, based on a voltage difference between upper and lower DC link capacitors respectively adapted to supply voltages to the inverter, thereby reducing a torque ripple generated in the motor. The apparatus includes a rectifier unit, upper and lower DC link capacitors connected in parallel to the rectifier unit, each of the capacitors serving to conduct charge and discharge operations for a DC voltage outputted from the rectifier unit, an inverter connected in parallel to the capacitors and adapted to generate a 3-phase voltage adapted to rotate the motor, based on voltages respectively discharged from the capacitors along with a switching signal, and a voltage command generator for calculating compensation components for respective switching operations of switching elements of A and B phases included in the inverter, based on a voltage difference between the capacitors, a difference between an actual motor speed and a command speed, and a rotor position, and providing respective switching times including the calculated compensation components, thereby controlling a rotating speed of the motor.

Dependencies are inferred from the claim text.