A discontinuous PWM strategy optimized for high-frequency pulsating-dc link inverters

This paper presents a discontinuous pulse width modulation (PWM) scheme optimized for three-phase high-frequency pulsating-dc link (HFPDCL) inverters. HFPDCL inverters consist of a high-frequency dc/ac converter, high-frequency (HF) transformers, a rectifier, and an output three-phase inverter. HF transformers provide galvanic isolation and reduce the transformer volume in the inverter. HFPDCL inverters do not require bulky DC-link capacitors; therefore, eliminating them from the power stage of the converter increases the power density and reliability of the HFPDCL inverters. The proposed discontinuous PWM scheme is optimized based on the HF pulsating-dc waveform of the dc link of the HFPDCL inverters. It decreases the switching requirement and generates high-quality output waveforms. It clamps one predetermined phase of the output inverter to the dc bus which decreases the switching requirement of the inverter. A 2 kW prototype HFPDCL inverter is implemented to verify the performance of the proposed discontinuous PWM scheme. Using the proposed DPWM scheme for the HFPDCL inverters improves the performance of the inverter.