Loss reduction in a medium frequency series resonance converter by forced evacuation

In this paper, a new loss-reduction measure is introduced for operating high voltage IGBTs in medium frequency series-resonant converters. The proposed solution is an additional electronic circuit, dubbed a forced evacuation switch, that assists with the evacuation of storage charge from the n∼-base of the IGBTs during turn-off transients. Advantages of the proposed solution include lower operating losses, in particular at low or no-load, and as a result, the ability to optimize the circuit for a broader range of current and power compared to existing solutions.