To cope with the challenge of more photovoltaic (PV) installation, the impact of the distributed PVs on the short-circuit current in distribution grids is analyzed. It is pointed out that the traditional fault location approach based on the fault current is fully adequate in the case that the PVs are installed on the upstream buses. The worst condition in the case of PVs installed on the feeders is given and the adaptability ranges of traditional fault location approach are deduced. Two fault location methods are proposed for the cases of the traditional fault location approach not satisfied, such as, the reclosing based method and the fault direction detection based method. The conclusions are drawn that no more than 1.5 times of the rated current may be seen from the PV whether three phase short-circuit or two-phase short-circuit occur. Almost all of the cable and overhead line based feeders meet the requirements of the traditional fault location approach when the PV installed no more than 25% of the capacity of the feeders. The two proposed fault location methods are feasible.%为了应对分布式光伏接入配电网的挑战，分析了分布式光伏的短路电流特征和分布式光伏接入对配电网短路电流的影响，指出当分布式光伏接入上游母线时，依据故障电流的传统故障定位策略完全适应。给出了分布式光伏接入馈线情形下的最不利条件，并分析了能够满足传统故障定位策略要求的适应范围。为了满足分布式光伏超出适应范围的故障定位要求，论述了两种应对方法，即重合闸与分布式光伏脱网特性配合法和基于方向元件法。研究结果表明：无论配电网发生三相或两相短路，由光伏供出的短路电流都不超过其额定电流的1.5倍；在分布式光伏接入容量不超过馈线载流量25%的条件下，电缆馈线基本都能满足传统故障定位规则要求、架空馈线绝大部分能满足传统故障定位规则要求。论述的两种应对方法能够满足分布式光伏超出适应范围的故障定位要求。
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