A series-connected asymmetrical PWM half-bridge three-level converter with reduced circulating current

Abstract

A novel three-level (TL) converter topology is proposed in this paper. The primary side of the proposed converter consists of two asymmetric half-bridge inverters, which are connected in series. The rectifier stage is composed of two parallel full-bridge-rectifier (FBR) which use the same diodes as the common current path. The asymmetrical-PWM control is employed to regulate output voltage. Compared with the traditional TL converters, the circulating current can be significantly reduced. Moreover, all the switches can achieve ZVS performance with a small leakage inductor over wide load range. The parallel connection of the two FBR also helps to reduce the current ripple of the filter inductor, leading to high density switching converter design. In this paper, a laboratory prototype(480-600 Vdc input, 96Vdc/12A output) based on the proposed converter is built to validate the theoretical analysis.

Modeling and simulation of three level dual active half bridge based on PI control

“…Under SPS modulation, TL-DAHB can change the direction and magnitude of transmission power by adjusting the phase-shift duty cycle between bridges. With the change of voltage transfer ratio, the current stress of the device also changes [5][6] . In order to get the desired output effect, there is a need to establish mathematical models of current stress and transmission power to take proper control measures.…”