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为解决由于分布式电源(distributed generation,DG)助增效应导致传统保护方案难以同时满足选择性和灵敏性要求的难题,从理论上揭示DG接入前后反时限过电流保护动作行为特性随故障点位置移动的变化规律,分析DG接入对反时限过电流保护性能造成的影响,提出一种具有高灵敏性的电压修正反时限过电流(voltage correction based inverse-time overcurrent,VCITO)保护方案,利用故障下电网电压的自然分布与测量电压随故障位置移动的变化规律,构造电压修正因子与电压梯度指数对反时限特性曲线进行修正.VCITO保护方案基于保护本地信息整定动作时间,在确保保护选择性的同时实现速动性最优化.利用PSCAD/EMTDC建立典型35kV含DG电网模型对VCITO保护方案进行验证,仿真结果表明该方案能有效解决传统反时限过电流保护在DG接入场景中存在的选择性失配与速动性弱化问题,且具有较强的灵敏性.“,”To solve the problem that traditional protection scheme can hardly satisfy the requirements of both coordination and sensitivity with distributed generation (DG) infeed effect, the operating behavior characteristics of inverse-time overcurrent protection with the changing of fault location with and without DG connection were revealed. The impacts of DG to the performance of inverse-time overcurrent protection were analyzed. A voltage correction based inverse-time overcurrent (VCITO) protection method with high sensitivity was proposed in this paper. Voltage correction factor and voltage correction gradient exponent, which are constructed based on the voltage natural distribution under fault and the change law of measuring voltage with the changing of fault location, was used to correct the inverse-time characteristic curve. The operating time of VCITO protection was obtained based on local information and it can ensure the coordination meanwhile the optimization of operating speed. A typical 35kV model with DG was established in PSCAD/ EMTDC and the simulation results proved that VCITO protection can solve the coordination and operating speed problems with DG connection and its sensitivity is high.