Floating source multilevel inverter uses hybrid double switching frequencies

In most of the power electronics inverters it is desired to produce clean sinusoidal waves without the use for any filtration in the output. This topic gathered the attentions of many researchers because it helps reduce the cost of the inverters. This paper presents floating source multilevel inverters that utilize double switching frequency modulation technique. This modulation method consists of inverse sinusoidal wave with two frequencies as a carrier. The modulation scheme uses hybrid method where one pair of the switches operates at high frequency using this carrier while the other switches are operated at the line frequency. This technique generated more steps in the inverter output while maintain the same number of switching devices. Besides, it reduces the total harmonic distortion because of the double frequency modulation technique by increasing the fundamental component of the inverter output waveform. The proposed method was verified by simulation using PSCAD/EMTPS.