Ripple Current Reduction in DC Link Capacitor by Harmonic Control of DC/DC Converter and PWM Inverter

Abstract

A novel technique for reducing the ripple current in a DC link capacitor by harmonic control of the DC/DC converter and PWM inverter is proposed in this paper. The proposed technique synchronizes the switching frequencies of the PWM inverter and the DC/DC converter and optimizes the phase difference of the carrier waveforms between them. The effectiveness of our technique is shown by simulation and an experiment conducted with a 10-kW PM motor drive system. In comparison to the conventional technique, the proposed technique reduces the ripple current in the DC link capacitor by 20-40% in a PWM inverter drive system with a DC/DC converter.