A snubber configuration suitable for energy recovery in three level GTO inverters

A simple snubber configuration for three-level GTO inverters is proposed. The proposed snubber has a single resistor per arm for the stored energy dissipation, while the conventional RLD/RCD snubber contains six. This implies that it needs only one chopper circuit per arm for snubber energy recovery; thus it helps in reducing the size, cost, and the number of components. Besides the resistor, the proposed snubber requires two less diodes per arm than the RLD/RCD snubber. Furthermore, the proposed snubber resolves the voltage unbalance problem between inner and outer GTOs without additional components. Here, the authors analyze the proposed circuits and prove their performance through simulation as well as experiments