| Abstract |
The class of resonant converters is very attractive due to its ability to achieve nearly lossless switching by using zero current or zero voltage switching (ZCS/ZVS) for the switching devices in the input bridge. Since most switched-mode power supplies (SMPS) today use MOSFETs as semiconductor devices, a ZVS operation is typically preferred. However, the ongoing trend towards higher switching frequencies makes reaching of ZVS more and more difficult. Thus, a (partial) loss of ZVS might be the consequence, making the need for a reasonable estimation of the occurring losses of vital importance. Due to the half- or full-bridge configuration, this estimation becomes much more complex compared to a traditional hard-switched boost or buck converter. This paper gives a detailed insight into the switching transients of resonant converters and proposes a proper test circuit. A powerful method is presented to estimate the generated switching and driving losses during the turn-on event of the switches in case of incomplete ZVS. This approach is purely based on the semiconductors' datasheet information. No additional knowledge about the internal device structure is necessary. |
