Dual-inductive snubber circuit design for three-level inverter

A new circuit design for the protection of e.g. multi level converters will be presented in this paper. The so-called ´dual-inductive snubber circuit design for three-level converter´ will optimize the number of the total snubber circuit elements and the behavior RCD/RLD snubber circuit especially in the direction of over-voltage and over-current, and will be suitable to be used in high power inverters as well as FACTS systems due to its features. The new design comprises most of the advantages of the common snubber circuit as a low number of components, improved efficiency and power semiconductor losses due to the low number of snubber elements, reduced over-voltage across the semiconductor devices and no balancing problems. The presented snubber circuit has been analyzed, compared, and confronted to the output of a standardized three level converter system to verify its advantages.