New lossless turn-on and turn-off (snubber) networks for inverters, including circuits for blocking voltage limitation

Transistorized pulse width modulated (PWM) inverters require careful dimensioning of turn-on and turn-off circuits in order to minimize the switching loss in the power transistors. The paper describes new lossless circuits. Especially the turn-off circuits show a highly reduced part count as compared to circuits known from the literature. Also the turn-on circuits apply energy recovery. Furthermore, due to a special circuit, the voltage across the power transistor is strictly limited. This is very important especially due to the usually low voltage blocking capability of high current power transistors.