Novel single-state PWM technique in multilevel inverter for unbalanced dc sources

Single-state PWM technique (SS PWM) presents an optimised switching losses PWM scheme to be applied for multilevel inverter for possible reducing number of switchings in a sampling period. Nonlinear control characteristics and harmonic distortion factor can be significantly improved if the number of levels is high. To implement a single-state PWM control with minimised voltage error on condition of unbalance dc sources, a compensating technique is required. The paper will propose a possible solution for implementing the SS PWM with minimised voltage error, using carrier based approach. This again demonstrates the utilisation of carrier based and space vector PWM relationship in solving various optimised PWM problems in multilevel inverters.