Carrier based two-state PWM method for optimising voltage error in multilevel inverters

In the paper, a carrier based two-state PWM technique will be proposed. This method is advantageous for reducing switching losses compared with conventional PWM techniques. Compared with single-state PWM method, it can achieve a better linear control characteristic and harmonic distortion performance. The carrier based PWM approach of the proposed method justifies a flexibility of carrier techniques for achieving various PWM performances in practice. Even for three-level inverter, the harmonic content is low for medium and high modulation index and more improved if the number of levels is high. The proposed method is mathematically formulated and demonstrated by simulation and experimental results.