A 5-Level Three-Phase Cascaded Hybrid Multilevel Inverter

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%.

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