Power quality enhancement in asymmetrical cascaded multilevel inverter using modified carrier level shifted pulse width modulation approach
Arun Vijayakumar, Albert Alexander Stonier, Geno Peter, Ashok Kumar Loganathan, Vivekananda Ganji
Abstract
Abstract New modified carrier‐based level shifted pulse width modulation approaches for single‐phase trinary dc source fed cascaded H‐bridge inverters are proposed in this article. In order to suppress the lower order harmonics, the carrier frequency is often tuned higher. However, switching and electromagnetic interference (EMI) problems have a significant influence on the functioning and controlling of the inverter at higher carrier frequency ranges. A new carrier is designed to address the aforementioned issues. To prove the effectiveness of the proposed carrier, this paper provides comparison results of conventional triangular carrier and a new developed carrier. Furthermore, utilizing the most popular phase disposition (PD) level shifted pulse width modulation approach with a new carrier with the similar modulation indices and switching frequency, to improve the fundamental voltage magnitude and shift the dominant harmonics into three times that of the existing traditional carrier‐based level shifted pulse width modulation approaches. The effectiveness and feasibility of the proposed new modified carrier‐based level shifted pulse width modulation approach have been proven by using MATLAB simulation and prototype results.