| Abstract |
This paper presents a novel soft switching quasi resonant 3-phase IGBT
inverter capable of operating at high switching frequency for high power applications (up to 100 kW). The circuit enables zero voltage switching with reduced device stresses for all switches. It provides reduced voltage rate of change du/dt and hence low
conducted and radiated emission.
The proposed inverter utilizes an auxiliary zero voltage switching circuit (ZVS) which can be triggered on demand, to create a zero-voltage switching interval for the inverter
switches, thereby ensuring nearly loss less switching. A simple control scheme of the clamp voltage is introduced to ensure the operation of
the circuit under variable load conditions. Experimental results from a 50 kVA, 400 V inverter for 3-phase load verified the expected advantages of the novel inverter concerning the switching frequency and du/dt stresses. The paper concludes with detailed comparison to the conventional hard switching 3-phase PWM IGBT inverter. |
