New DC Rail Side Soft-Switching PWM DC-DC Converter with Voltage Doubler Rectifier for PV Generation Interface

This paper presents a new circuit topology of active edge resonant snubbers assisted half-bridge soft switching PWM inverter type high power dc-dc converter for photovoltaic applications. The proposed step-up DC/DC converters with transformer isolation can obtain high voltage step-up trough turns ratio. The proposed dc-dc power converter is composed of typical voltage source-fed half-bridge high frequency PWM inverter with a high frequency transformer link in addition to input DC busline side power semiconductor switching devices for PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC buslines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, a high switching frequency IGHTs can be actually selected in the frequency range of 60 kHz under principle of soft switching.