Princípio de integração de circuitos de auxílio à comutação: o estudo do caso ZVT

Abstract

The main contribution of this Thesis is the proposition of the integration concept of auxiliary commutation circuits applied to systems with several power conversion stages. Trough this concept, the reactive energy resulting from a commutation is used to assist another one, resulting in a high efficiency system. Another advantage of the integrated auxiliary commutation circuits (iACC) is their reduced cost, once only one iACC is used to achieve soft-commutation in all converters that compose the system. The utilization of the UPSs double conversion to demonstrate the proposed integration concept resulted in several high efficiency and high power density topologies. To make the iACCs creation and utilization easier, it was proposed the general rules to generate new iACCs and the design methodology. By using these integrated circuits, the main switches operate under soft-commutation of iZVT type, and the auxiliary switches, under ZCS or ZVS type. To verify the design methodology, the efficiency and the operation of the new iACCs seven prototypes with power varying between 580W and 1200W were built.