有源配电网保护整定方法及分布式电源准入容量分析OA

To address the issues of failure to operate or maloperation of traditional three-stage overcurrent protection in distribution networks which are caused by the integration of inverter-interfaced distributed generators represented by photovoltaic sources,a protection setting method for active distribution networks is proposed in this paper,and an analy-sis of the corresponding distributed generation penetration capacity is also performed.First,considering the influences of phase-to-phase short-circuit fault types,fault locations and operation modes,the variation patterns of fault current se-quence components,fault phase current and phase-to-phase current in the fault phase under phase-to-phase short-cir-cuit faults in active distribution networks are analyzed.On this basis,an effective simplification method aggregating mul-tiple distributed generators on the same line is adopted to comprehensively incorporate the output current from distribut-ed generators and their grid-connection locations into the protection setting.In addition,combined with the traditional three-stage overcurrent protection setting methodology,a current protection setting method for active distribution net-works based on phase-to-phase current in the fault phase is put forward.Furthermore,with the combination of selectivity and sensitivity constraints on the protection,the calculation methods for the penetration capacity of distributed genera-tors which locate upstream of the protection,within the protection zone and downstream of the protection are given,re-spectively.Modeling and fault simulation of active distribution networks conducted in PSCAD/EMTDC verify the correct-ness of the fault characteristic analysis results,as well as the effectiveness of the proposed protection setting method.