A new space vector modulation strategy for three-switch three-phase delta inverter

Abstract

The three-switch three-phase inverter (TSTPI) also referred to as delta inverter is a three-phase dc/ac converter that needs only three two-quadrant power switches. This reduced power conversion structure is widely considered in many industrial applications, especially the electrical traction thanks to its costly-effectiveness, compactness, lower complexity and lower switching losses. This paper presents a new space vector modulation method (SVPWM) of the TSTPI. The proposed method uses at any switching period the three largest active vectors to synthesize the reference output voltage vector. It compares also two distribution strategies of the gate signals. Computer simulations carried out on a numerical model of the converter feeding an RL load confirm the validity of the proposed SVPWM method. The correct operation of the converter controlled with the SVPWM method is also emphasized through experimental tests realized on a laboratory prototype of the inverter.