A Family of DC Transformer (DCX) Topologies Based on New ZVZCS Cells With DC Resonant Capacitance

摘要

The series resonant soft-switching topology is widely used in high-density DCX products due to its zero switching loss. But, the conventional series resonant converter is a dual end topology, which results in complex circuit structure and high cost. In order to simplify the resonant DCX topology and reduce the cost, a novel resonant cell named input current fed (ICF) cell is proposed in this paper, which can be applied to single-ended forward topologies. The zero-voltage-switching (ZVS) on and quasi-zero-current-switching (ZCS) off for switch are both achieved. According to the duality theory of circuit, another output current sink cell is derived. Based on the proposed ZVZCS ICF cell, two cells are interleaved to construct several dual end cells, which can be extended to push-pull, full bridge, half bridge, and other dual end topologies. Based on these cells, a new family of ZVZCS resonant DCX is derived, which are suitable for high-frequency and high-efficiency applications with various power levels. The operating principle and characteristics of the cells and topologies are verified by simulations and experimental results.