电动汽车充电站中谐波相互抑制的研究

Research of Mitigating Harmonic by Harmonic in Electric Vehicle Chargers

通过建立充电站仿真模型,研究充电机输出功率和变压器接线方式对谐波电流相位的影响.仿真结果表明充电机输出功率相差越大,谐波电流相位差越大;变压器联结方式对高压侧谐波电流相位影响很大.根据仿真结果,通过增大多台充电机输出功率之间的差距,使多台充电机谐波电流之间产生最大可能的相互抑制;在同一母线上连接2台采用Yy0和Yd11联结方式的变压器为2组充电机供电,能使2组6脉波整流充电机产生的5次、7次谐波电流在电源处相互抑制;2组充电机输出功率越接近,谐波抑制效果越好.

In order to mitigate harmonic by harmonic current for the maximum possible in charging sta- tion, a simulation model of chargers is established to study the influence that the output power of charger and the mode of transformer connection have on the harmonic current phase. The results of simulation in- dicate that the bigger the difference of the output power of charger is, the bigger the difference of harmonic current phase is, and that the type of transformer connection has more influence on the harmonic current phase of the high voltage side. Based on the conclusion, the method that increases the gap of the output power of chargers is put forward to achieve the harmonic suppression for the maximum possible between chargers; When two transformers （the connection type are Yy0 and Yd11）are linked to a same bus bar to supply power for two groups of chargers, the most of the 5th, 7th harmonic current produced by 6 pulse rectifier charger can be mitigated at power source. And the closer the output power of chargers is, the bet- ter the effect of harmonic suppression is.