Zero-voltage-swiching (ZVS) and zero- current-switching (ZCS) are methods for resonant converters used in power supplies. Zero-voltage switches minimize switching losses in the switching transistors, they generate only low electromagnetic interference, reduce the power dissipation of the converters and thus increase its efficiency.
Particularly in power supplies, efficiency plays a decisive role because of the improved energy balance. When switching in zero-crossing, no current flows, making forward losses zero. At the same time, the power density increases and so does the efficiency. A further improvement in power density is possible by increasing the switching frequency.