Single-Phase Full-Power Operable Three-Phase Buck-Boost Y-Rectifier Concepts

Abstract

Future electric vehicle chargers should feature full nominal output power in single-phase (1-Phi) and three-phase (3-Phi) operation, such that they can be employed in the USA as well as in Europe. Further, the converter system should have buck-boost capability to cover a wide DC output voltage range in order to provide compatibility with various nominal battery voltage levels. The phase-modular Y-Rectifier consists of three buck-boost converter modules, features unity power factor operation and allows for an ultra-compact and highly efficient converter realization, where so far only 3-Phi operation was investigated in literature. In this paper, circuit extensions adapting the Y-Rectifier for both 1-Phi and 3-Phi operation are analyzed and comparatively evaluated, where also a new six-module Y-Rectifier ( 6M-YR) topology is proposed. The required modulation and control techniques of the 6M-YR are presented for 1-Phi and 3-Phi operation. The discussed topologies are then compared by means of a component current conduction stress and a power stage performance analysis for a 6.6kW, 3-Phi 400V (Europe) / 1-Phi 240V (USA) AC, 200V to 750V DC application. Further, EMI filter design guidelines for the 6M-YR are presented. The results indicate the feasibility of a highly compact CISPR 11 Class B compliant 6M-YR with a power density of 10kW/dm(3) (164W/in(3)) and a nominal efficiency of 98.1% in 3-Phi and 97.6% in 1-Phi operation.