One of the most important demands of the today's high power electronics market is the high power density/efficiency. On one hand, power semiconductor manufacturers are developing high power IGBTs with lower commutation losses, where each new generation becomes faster and faster. On other hand, lot of work has been done on improvement of the switching performances of the IGBT by using active gate driving techniques. Every one of those well known solutions has its benefits and drawbacks, some better optimize turn-on, others are better for turn-off transient. Some are more or less complicated and more suitable for specific applications. In order to describe all these control techniques, it would be required to write several papers, but one issue is common for both active and conventional gate drivers-problem with collector-emitter overvoltage. Faster IGBTs achieve better characteristics (power factor) at higher switching frequencies. However, faster switching of the collector current inherently introduces a problem of the turn-off over-voltage. In a case of overload or short circuit fault, the IGBT peak voltage can reach the breakdown voltage and the IGBT can be easily destroyed. This paper is focused on the solution that nowadays becomes a "must", and not "nice to have", feature-active clamping. Benefits of the active clamping of the IGBT, but also some difficulties in implementation are discussed in details. Various experimental results are presented in the paper.
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