Switching Power Converters, 2nd Edition

11	Resonant Three-Phase Converters

11.1    REDUCING SWITCHING LOSSES THROUGH RESONANCE VERSUS ADVANCED PWM DEVICES

It has been shown in the introduction that a switching operation is adopted in high-power converters in order to reduce losses and to improve efficiency. However, the operation of the power semiconductor devices is far from ideal and losses still occur. It has also been shown in Chapter 2 that these losses arise during ON-time and during transient events.

Losses during ON-time are called conduction losses and they depend entirely on the voltage drop across the switching device. Modern MOSFET devices feature very low R_ds(on) [1]. For instance, the CoolMOS devices can switch up to 85 A at 600 V and benefit from an R_ds(on) of 35–70 ...