A Simplified Lossless Passive Soft-Switching Snubber for PWM Half-Bridge Inverters

This paper presents a simplified lossless passive snubber regenerative circuit to achieve soft-switching purpose. This lossless passive soft-switching snubber(LPSSS) employs a diode and capacitor for each main switch to provide low dv/dt and low switching stresses, achieving ZVS(zero voltage soft-switching) turn-off. This LPSSS further uses an inductor to achieve ZCS(zero current soft-switching) turn-on for both main switches. In addition, the energy regenerative circuit uses a buffer capacitor and a resonant inductor to recover the snubber energy into the DC rail based on a series of resonance, which achieves the combination of snubber technique and resonance technique. This LPSSS circuit has been incorporated into a PWM half-bridge inverter, and the working principle and operating characteristics are described, together with the parameters design and the simulation in saber.