A Dual-use Snubber Design for Multi-Level Inverter Systems

In this paper a new snubber circuit design for three-level inverter will be presented. The so-called "dual snubber circuit" still comprises most of the positive features as a low number of components, improved efficiency due to the low snubber element and power semiconductor losses, reduced over-voltage across the semiconductor devices and no balancing problems. With these advantages, the new dual-use snubber circuit can be used for high power inverters as well as the so-called flexible AC transmission systems (FACTS). The presented snubber circuit has been analyzed and confronted with different existing converter designs using a simulation environment. The simulation results are compared with the output of a standardized three level converter system to verify the advantages of the new snubber design