A current source based snubber energy recovery circuit for GTO inverters

In a large capacity GTO inverter, the amount of energy stored in the snubber circuit is significant. It is therefore desirable to recover as much of this energy as possible. A snubber energy recovery circuit which is an extension of the basic snubber circuit is presented. It contains no resistive elements so is theoretically lossless. The snubber energy is recovered via a constant current source which limits the peak snubber capacitor discharge current that will flow through the GTO at turn-on. The application of the proposed circuit to a half-bridge GTO inverter and a 2-series GTO inverter are discussed.<>