一种新型城轨车辆移相全桥变换电路研究

Research on a new phase shift full bridge converter circuit for urban rail vehicles

为了提高传统移相全桥电路在大功率和宽范围输出电压下很难满足半载以下软开关需求,以及电路损耗高的问题,设计了一种新型移相全桥变换电路,即在最难实现软开关的滞后桥臂并联辅助电流源网络,改变移相全桥电路的工作模态,使滞后桥臂在宽范围负载下仍可实现软开关,同时降低电路损耗。对所设计的电路进行仿真和损耗分析,新型移相全桥电路可满足在输出电压77~137.5 V下19%~100%额定负载的软开关需求,相较于传统电路软开关范围提升约15%,同时在软开关范围内,新型移相全桥电路开关器件效率大于96.3%,证明了设计方案的合理性。

In order to improve the traditional phase-shifting full bridge converter circuit which is difficult to meet the demand for soft switching under half load under high power and wide range of output voltage, and the problem of high circuit loss, we have designed a new phase-shifting full bridge converter circuit, that is, the auxiliary current source network is connected in parallel on the lagging leg, which is the most difficult to achieve soft switching, so that change the operating mode of phase-shifting full bridge circuit and the lagging bridge arm can still achieve soft switching under a wide range of load, while reducing circuit loss. The simulation and loss analysis of the designed circuit prove show that the new phase-shift full-bridge circuit can meet the soft switching requirements of 19%~100% of the rated load at the output voltage of 77~137.5 V, which is about 15% higher than the traditional circuit soft switching range. Meanwhile, in the range of soft switching, the efficiency of the new phase-shifting full-bridge circuit switching device is greater than 96.3%. The rationality of the proposed design scheme is proved.