新型充分式含DG配网保护策略研究

Currently, protection methods for distribution system with DG are still inapplicable and unsatisfactory. DG is still isolated if any network fault was detected, which as a strategy has been hindered further development of renewable energy generation technology. In this proposal, the "sufficient criterion protection" is proposed. The purpose of which is to solve protection problems under the existing information missing and communication network limitation in distribution system with DG. The new protection methods work with any accessible state and time-related information, detect fault sufficiently, and cooperate with the new DG isolation technology. The new criterion has characteristcs as follow: sufficent judgement, information adaptivity, optimal proccessing and relaibility, all of which play the significant roles in overcome the adverse condition for protection such as multi-sources and information missing. The keynote of the criterion is to optimize information, and detect fault based on any reliable sufficient characteristic, and works with rigorous selectivity. There would be no need to reconstruct the existing distribution network, but also meet its need of further development. The project will invistigate: sufficient criterion protection; sufficient performance study on current protection methods for distribution system with DG; single ended, double ended, multiple ended information optimal selecting protection method; cooperation mechanism study of sufficient fault detection and DG isolation; information aysnchronously selecting method for sufficient criterion protection; cooperation mechanism study of sufficient protection with microgrids and island.

新能源接入配网后的保护尚未有实用技术，仍采用故障时隔离全部DG的简单方法，配网保护明显滞后新能源的发展。项目提出"充分式"保护理论，针对含DG配网存在大量信息无法获取或缺失，通信网络简单等特点，采用能够得到的有限状态信息和时间相关性信息构成充分式的故障判定条件，并在此基础上配合DG自动隔离技术实现含DG配网保护的一种新原理。项目利用原理所具有的充分、自适应、优选等特点，充分应对多DG接入和信息分散、不全的配网特征。核心特点是能够充分组织所获得信息，针对故障的某一充分特征采用相应判据应对，具有严格的选择性。同时项目的新技术对现有配网没有进行大量改造的客观要求，并完全适应配网未来的发展。 项目将用充分式原理对下列问题进行研究：充分式保护原理研究，现有保护的充分性研究，单端多端充分式保护方案研究，充分式故障划分和DG隔离协调技术研究，充分式条件异步优选方案研究，充分式保护和微网、孤岛协调研究等。

配网存在大量信息无法获取或缺失、通信网络简单等特点使得含DG配网尚无实用保护技术，仍采用故障时隔离全部DG的简单方法，不利于分布式电源的长远发展。本项目提出了应用于含DG配网的充分式保护理论，深入研究了充分式保护原理、多端信息获取、充分式故障划分、充分式条件异步优选、微网孤岛协调保护、DG隔离底限方案等关键技术及其实现方法。通过深度挖掘含DG配网的有限状态信息和时间相关性信息，研究了大量的充分式故障判定条件，在此基础上提出了基于相邻线路电流信息的充分式电流保护、基于充分式方向元件的电流保护、基于电流相位变化量特性的充分式差动保护、基于电流幅值差异特征的充分式纵联保护、基于故障同步识别技术的充分式差动保护、基于电压搜索树原理的故障定位、基于边电压的反时限微网保护方案、基于小波分析的DG自动隔离策略等新型的含DG配网保护策略。本项目提出的新技术无需对现有配网进行大量改造，完全适应含DG配网未来的发展。依托该项目发表了国内核心期刊论文18篇，国内外会议论文17篇，共24篇被EI收录；培养了6名博士研究生以及21名硕士研究生。