NEW SNUBBER CIRCUIT WITH PASSIVE ENERGY RECOVERY FOR POWER INVERTERS

The paper proposes a new passive circuit for partial snubber-energy re covery in GTO thyristor high-power voltage-source inverters. The analy sis and simulations show that the proposed bridge-leg snubber circuit can recover greater than sixty five per cent of the total snubber ener gy, as well as the freewheel diode reverse recovery energy. This energ y is recovered back to the DC supply through a closely coupled transfo rmer, without any active devices or associated control circuitry. This snubber circuit, being simple, is particularly suitable for use in GT O thyristor high-power inverters. Design equations, simulations and ex perimental results are given.