考虑多DG接入的配电网自适应电流主保护方案

为解决多个分布式电源（DG）接入配电网后保护装置拒动、误动、灵敏度低的问题，提出了一种考虑多DG接入配电网的自适应电流主保护方案。首先建立PQ控制的IIDG模型，分析多DG接入影响。然后根据故障复合序分量的关系，求解在线路不同位置发生两相短路、三相短路故障时各保护安装处的正序电流，提出改进的自适应Ⅰ段电流保护方案；并基于不超过下级线路Ⅰ段电流保护最大保护范围提出改进的自适应Ⅱ段电流保护方案。最后在PSCAD上搭建含多DG的10kV配电网模型，仿真验证了所提方案不仅能够保护线路全长，且具有较高的灵敏度与可靠性。

Adaptive Current Main Protection Scheme of Distribution Network Accessed With Multiple Distributed Generations

In order to solve the problems of maloperation，misoperation and low sensitivity of the protection device after multiple DGs accessing to distribution network，an adaptive main current protection scheme of distribution network accessed with multiple DGs is proposed. Firstly， the IIDG model of PQ control is established to analyze the influences of multiple DGs access. Then， according to the relationship of composite sequence components of faults， the positive sequence current of each protection installation when two-phase short circuit and three-phase short circuit faults occur at different positions of the line is solved， and an improved adaptive current protection scheme in section I is proposed. An improved adaptive section II current protection scheme is proposed based on scope which is no more than the maximum protection range of the lower line section I current protection. Finally， 10kV distribution network model with multiple DGs is built in PSCAD，the simulation results show that the proposed scheme can not only protect the full length of the line，but also has high sensitivity and reliability.