In electric vehicle (EV) charging stations equipped with shunt active power filters (APFs), the operation of the shunt APF may amplify (harmonic amplification) the charging current harmonics at the point of power collection. This paper focuses on an EV charging station with three-phase uncontrolled rectification chargers that produces the most serious harmonic pollution. By analyzing the coupling relationship between harmonic current and voltage of EV charging stations, as well as by defining the total harmonic current amplification factor, this paper proposes an analytical method to quantify the amplification degree of charging current at the point of power collection. On this basis, the variation trends show how the amplification factor changes with key parameters, such as quantity of chargers, compensation rate, and compensation phase difference of APFs are discussed. The results are beneficial to gaining further understanding on capacity correction and control design of APFs in an EV charging station.%电动汽车充电站并联有源滤波器工作时，可能引起流过充电站集电母线的充电电流谐波出现放大效应。针对谐波污染最严重的三相不可控整流充电机，研究充电站各次谐波电流与谐波电压的耦合关系，定义电动汽车充电站总谐波电流放大系数，提出一种充电站集电母线电流谐波放大程度的量化方法。该方法实现了电流谐波放大效应的解析计算且具有较高精度。在此基础上，探讨谐波放大系数随充电机台数、有源滤波补偿率及相位差等因素的变化规律，为有源滤波器容量配置与控制设计提供依据。
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