Hybrid Carrier Frequency Based Modulation Strategy to Improve Efficiency of Voltage Source Inverter

Rapid advancement of high-speed power switching devices lead to widespread usage of Voltage Source Inverter (VSI) in variable speed drive systems. The quality of the power delivered by a VSI is highly dependent on the modulation strategy. Pulse Width Modulation (PWM) is the traditional modulation strategy for VSIs. PWMs are generated mostly based on fixed frequency carrier waveform. These classical modulation strategies suffer from the high total harmonic distortion in low carrier frequency (CF) and high-power loss in high CF. To diminish the THD (Total Harmonic Distortion) and power loss of the VSI, this paper proposes a hybrid carrier frequency (HCF) method. The performance of the proposed method has been tested on an experimental setup for a validation and the results are compared with the classical approach. The experimental results demonstrate that the proposed approach increases the efficiency by reducing the switching losses without increasing the complexity of the PWM.