Three-phase soft-switching voltage source converters for motor drives. I. Overview and analysis

In the last twenty years, industrial and academic research has produced over one hundred new resonant and soft switching voltage source converter topologies. Regrettably, most of the published work has been directed toward a single topology, giving an overall impression of a large number of unconnected, competing techniques. To provide insight into this wide-ranging subject area, an overview of converter topologies is presented. Each topology is classified according to its mode of operation, and a family tree is derived, encompassing all converter types. Selected converters in each class are analysed, normalised performance figures are determined and key operational characteristics identified. Issues associated with the practical implementation of the analysed topologies are discussed in detail. The following topologies are analysed: soft switching DC-link converters, basic resonant DC-link inverter (BRDCL), clamped BRDCL, clamped quasi-resonant DC-link, parallel resonant DC-link inverter, and pole-commutated inverters