Double two-switch forward transformer linked soft-switching PWM DC-DC power converter using IGBTs

A double two-switch forward type high-frequency transformer linked zero-voltage and zero-current mode soft-switching (ZVZCS) pulse width modulation (PWM) DC-DC power converter using IGBTs is presented. A new circuit configuration of the isolated type PWM softly switching converter is proposed to reduce idling and circulating currents in the main circuit without using complex additional active auxiliary resonant snubber circuits and power semiconductor devices, and to decrease the peak voltage across power devices, and their peak current stresses. This soft-switching PWM DC-DC power converter has the unique advantages of less power circuit components and power semiconductor devices, high power conversion efficiency, constant frequency duty cycle control scheme, cost-effective and stable soft-switching operating range under wide load variations for high power applications. The basic operating principle of the soft-switching power converter treated here is illustrated using periodic steady-state circuit analysis for each mode equivalent circuit. The effectiveness of the proposed soft-switching DC-DC power converter built and tested as a 500 W-100 kHz breadboard setup using IGBTs is verified and evaluated on the basis of simulation and theoretical circuit analysis.