A new boost type cascaded inverter with single DC source

摘要

Cascaded multilevel inverters with Y-connection or Delta-connection have been proposed for high voltage applications. However, these topologies always require isolated transformers for each inverter cell, which makes cost high and wiring complex. Furthermore, system weight and volume also increase accordingly. This paper presents two new types of boost type delta-connection cascaded inverters with only a single DC source. Based on it, a suitable voltage control with PWM modulation is also proposed to improve the inverter control performance and DC capacitors voltage fluctuation. Verification has been carried out by simulation with MATLAB.