Abstract—This paper presents a 5-level three-phase cascaded hybrid multilevel inverter that consists of a standard 3-leg (one leg for each phase) and H-bridge in series with each inverter leg with separate DC voltage sources, 24V and 48V. The control signals for this hybrid multilevel inverter are implemented by a FPGA controller using PWM signal modulated technique and digital technique. A 5-level three-phase cascaded hybrid multilevel inverter model based on PSCAD/EMTDC is presented in this paper. The proposed hybrid multilevel inverter is described in detail that it is verified experimentally in three types of load; 18W fluorescent lamp-ballast, RL, and 1HP 3-phase induction motor; without filtering. Results of the experiment; the output waveform of line-line and phase voltages has 5 levels that percent of THD is between 15.6% and 18.3%, the output waveform of phase current is close to sinusoidal that percent of THD is between 2.7% and 4.2%.

Index Terms—Hybrid multilevel inverter, PSCAD/EMTDC, FPGA controller, h-bridge

P. Thongprasri is with the Department of Electrical Engineering, Faculty of Engineering at Si Racha, Kasetsart University Si Racha Campus, Chonburi, Thailand (e-mail: sfengprt@ src.ku.ac.th).

Cite: P. Thongprasri, "A 5-Level Three-Phase Cascaded Hybrid Multilevel Inverter," International Journal of Computer and Electrical Engineering vol. 3, no. 6, pp. 789-794, 2011.