Restraint Method of Torque Ripple with d-q Transformation and Torque Current Feedback in Power Converter System for AC Electric Cars

Abstract

In Power converter system for AC Electric cars, DC voltage contains a ripple component with a frequency twice as high as the line voltage frequency, because of the single-phase voltage source. Therefore, an inverter current ripple and a torque ripple of motors connected with the inverter in the power converter occur. The feedfoward beatless control can restrain the current ripple and the toque ripple has been proposed. It compensates the inverter frequency based on the ripple component of DC voltage. However, it is difficult to minimize the ripple component of the inverter and torque with the beatless control, because optimal compensation gain and phase depend on inverter frequency and other parameters. This paper proposes a feedback beatless control can minimize the torque ripple of the motors with the d-q transformation and the torque current ripple feedback and shows the effectiveness of the beatless control with an experimental result. © 2001, The Institute of Electrical Engineers of Japan. All rights reserved.