电动汽车车载充电器辅助电源的高效设计

High Efficient Design of Auxiliary Power Supply for Vehicle Charger of Electric Vehicle

为了满足电动汽车车载充电器系统辅助电源要实现宽范围电压输入和多路隔离输出的实际需求,选择单端反激式多路输出作为辅助电源主电路拓扑,详细介绍了其主电路中高频变压器、RCD电路和输出电容设计步骤及参数确定依据.控制系统采用电压外环和电流内环相结合的控制方案,其中电流内环采用峰值电流控制,基于Iw1691控制芯片将自适应多模式控制和谷值开关控制相结合,减少开关管开关损耗,实现系统的高效运行.最后,通过系统仿真测试和样机测试证实设计方案的合理有效性.

To achieve a wide range of input voltage and isolated multi-output of the auxiliary power supply for the on-board charger of EV, the single- ended flyback multi-output converter was chosen as the main circuit topology. The design procedure of circuit parameters including high-frequency transformer, RCD snubber circuit and output capacitor is described in detail. An outer voltage loop and an inner current loop are used in the control system, while the current loop operates in the peak current mode. The controller features the combination of the adaptive multi-mode control and valley switching control to reduce the switching loss of MOSFET based on the control chip Iw1691 to achieve high efficient operation of system. Finally, the system simulation and experimental results provided from the prototype confirm the validity of the proposed design scheme.