Implementation and Analysis of Five-Level inverter with Space Vector PWM Algorithm

Multilevel inverter has become integral part of all commercial equipments. The more attention is going towards further development of multilevel inverters. By increasing number of levels output voltage reaches close to sinusoidal waveform. In conventional two level inverter the switching loss increases with increase in switching frequency in order to obtain optimized harmonic profile. But switching frequency is restricted by switching losses. This paper also presents generalized space vector PWM technique for five-level inverter. With the help of this algorithm the location of reference vector and dwelling times of corresponding space vectors can be easily found out for any level of inverter. In order to obtain smooth switching and to reduce the complexity of redundant states selection (RSS), the middle vector is selected for odd redundancy and two centered vectors selected for even redundancy. The main advantage offered by this method gives reduced total harmonic distortion (THD) with less switching losses. By increasing levels of output voltage electromagnetic interference (EMI) effect also reduced. The simulation results of output voltage and line currents supporting this algorithm are also presented.