中文摘要：

为探讨分布式发电（DG）的并网运行将可能对原变电站的继电保护带来哪些影响，以生物质能发电厂接入110kV终端变电站为例．从故障点是否出现在系统电源进线入手，通过分析DG接入对变电站线路短路电流增量的影响以及线路故障尚未切除时DG能够满足暂态稳定运行时间的长短．进而研究分布式电源的不同容量、不同接入方式对所接入变电站原有三段式电流继电保护的影响，并通过EMTDC／PSCAD仿真加以验证。研究结果表明．在不考虑孤岛运行的前提下，分布式电源可能会对所接入的变电站出线三段式电流保护产生影响：对电流保护的动作电流定值的影响主要取决于DG容量的大小，会对哪些段的动作电流定值产生影响取决于故障时DG失稳时间的长短．

英文摘要：

With a biomass energy power plant connected to 110 kV terminal substation as an example,the impact of DG（Distributed Generation） capacity and connection mode on three-section overcurrent protection of substation is discussed from different aspects：the fault location,the short circuit current increment and the steady running time of DG after fault. Simulative results with EMTDC/PSCAD show that：without islanded operation,DG has impact on the trip current setting depending on its capacity and which section is influenced denending on its steady running time.