Simplified generic on-line PWM technique for single phase grid connected current source inverters

Abstract

Mandatory restrictions for a current source inverter's (CSI's) proper operation, like continuity of the DC link current, complicate the corresponding PWM generation especially in the case of single phase systems. Classical modulation techniques for single phase CSIs suffer from either complexity or unsymmetrical gate signals distribution for the inverter switches. In this paper, a PWM generation technique suitable for single phase CSI's is presented. The proposed technique ensures CSI's adequate operation with the advantages of: (i) Simple generic on-line implementation, (ii) Better utilization of the carrier frequency and (iii) Symmetrical distribution of the inverter's gate signals that ensures equal loss sharing, conduction and switching, among the inverter power semiconductors. System results, using simulations in addition to experimental setup, are utilized to validate the effectiveness of the proposed technique.