高频交流链接技术充电电源输入电流的改善

Improvement on input current character of charging power supply based on HF AC-link technology

基于高频交流链接技术(HF AC-link)的充电电源不仅能够实现常规电源的充电精度,还具有高比功率、内部低储能、输入端低谐波电流、高功率因数的优点;输入端的高性能是AC-link技术追求的目标之一,在控制算法准确的条件下,当前基于高频交流链接技术的充电电源的输入电流仍有较明显畸变。对工作在高链接频率下基于AC-link技术充电电源的电流畸变现象进行分类,并对畸变原因进行了分析,给出了控制策略和控制算法的改进方案,在平均功率20 k W,峰值电压5 k V充电电源上进行实验,实验结果表明,改善方案将输入电流总谐波含量(THD)由22%降低到7.5%,功率因数由0.97提高到0.99。

Not only the same output accuracy of capacitor charging power supply based on HF AC-link could be achieved as the conventional ones, but also high power density, low internal energy storage, low input current harmonic and high power factor were the characters. High input performance was one of the goals of AC-link technology, on the conditions of accurate control algorithm, the input current still had obvious distortion of the charging power supply based on HF AC-link. The phenomenon of input current distortion produced by charging power supply with AC-link technology using high link was firstly classified, and then the reason was analyzed in detail, the modified scheme of control strategy and control algorithm were given. Finally, the experiment on the20 k W,5k V charging module was carried out. The experiment result shows that by using the modified scheme,the total harmonic distortion（THD） decrease to 7.5% from 22% and the power factor（PF） rise to 0.99 from 0.97.