Published By: Blue Eyes Intelligence Engineering

Abstract — This paper presents a simplified advanced Pulse width Modulation algorithms for reduced common mode voltage variations. These algorithms have been developed by using the concept of imaginary switching times and hence did not use angle and sector information. Thus, the proposed algorithms reduce the complexity involved in the existing PWM algorithms. In the conventional SVPWM method, two adjacent states with two zero voltage vectors are utilized to program the output voltage. Every 600 degrees the active voltage vectors change, but the zero state locations are retained. In the AZSPWM methods, the choice and the sequence of active voltage vectors are the same as in conventional SVPWM. However, instead of the real zero voltage vectors (V0 and V7), two active opposite voltage vectors with equal duration are utilized. In the NSPWM algorithm, in each sector any one of the phases is clamped to either positive or negative DC bus for a total of 120o over a fundamental cycle. Hence, it reduces the switching losses of the inverter and switching frequency of the inverter by 33.33%. Among the proposed algorithms, the NSPWM algorithm gives superior performance with reduced switching losses of the inverter. Index Terms—Common mode voltage, induction motor drive