A Modular Three-Phase Diode Rectifier with High-Frequency Isolation and Sinusoidal Input Currents

This paper proposes a modular three-phase diode rectifier with high frequency isolation and sinusoidal input currents. The proposed system consists of modular AC-AC converters with 20 kHz transformer isolation on the primary side. A new hybrid pulse width modulation scheme is proposed that combines the high frequency 20kHz with a low frequency selective elimination of 5th, 7th, 11th and 13th current harmonics in the input such that the resulting utility current is nearly sinusoidal. The secondary side consists of a standard three-phase diode rectifier for a high quality dc output voltage suitable for ev-charging/switch mode power supplied in data centers etc. The proposed approach is modular and the output voltage is regulated via simple duty cycle control. Simulation results are discussed in the summary. Experimental results are presented on laboratory 208 V three phase, 1kW prototype hardware.