This paper presents a geometric approach for PWM modulation of three-leg inverters driving two-phase induction machines (TPIM). The main contribution of proposed scheme is the low computational effort to obtain symmetrical and asymmetrical line voltages suitable to fed two-phase induction machines. It is demonstrated that the amplitudes of line voltages can to vary from zero until 0.707 pu of DC-link for symmetrical output, while one of the voltages can overcome 0.707 pu of DC-link voltage in the asymmetrical case. The results obtained with the proposed modulation technique are similar to those obtained with space vector modulation, however, the implementation of the proposed modulation technique is much more simpler than the implementation of space vector modulation. Experimental results that validate the theoretical analysis are presented and they demonstrate the good performance and simplicity of the proposed modulation method.
Three-leg voltage source inverter; Two-phase induction machine; PWM modulation
