基于零序电压柔性控制的配电网接地故障消弧与保护新原理

项目名称： 基于零序电压柔性控制的配电网接地故障消弧与保护新原理

项目编号： No.51277014

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 电工技术

项目作者： 曾祥君

作者单位： 长沙理工大学

项目金额： 82万元

中文摘要： 为解决中性点非有效接地配电网长期存在的过电压、单相接地故障消弧与接地保护难题，借鉴电能质量控制领域的静止同步补偿器（STATCOM）思想，建立零序电压柔性控制及接地故障有源电压消弧与接地保护新理论。揭示注入零序电流对零序电压的作用机理，提出接地故障的动态辨识方法及消弧与保护新原理。发明过电压抑制和接地故障处理新方法：在配电网正常运行时，基于PWM有源逆变注入零序电流，补偿三相不平衡电流，吸收暂态零序能量，抑制零序过电压；在接地故障初始时间，注入零序电流，控制零序电压，强迫故障点电压为零，使故障残流为零，实现瞬时故障100%消弧；接地故障一定延时后，在注入电流中叠加测量信号，优化控制信号大小、频率和相位，精确测量故障特征参数，实现永久性故障的动态感知和保护与定位。并研究零序电压柔性控制及故障保护与定位算法，完成原理样机研制。有望改善配电网电能质量，降低故障建弧率，提高接地保护灵敏度和可靠性。

中文关键词： 配电网；接地故障；接地保护；零序电压调控；有源逆变

英文摘要： In order to solve the problems of over-voltage, arc extinguishing and protection for single-phase grounding faults in distribution networks, a novel zero sequence voltage flexible control method, fault arc extinguishing and ground protection theories with active voltage control are built with the idea reference of static synchronous compensator (STATCOM) in this project. The work mechanism of the injecting zero-sequence current to zero sequence voltage is analyzed; the grounding faults dynamic identification method, arc extinguishing and faults protection principle are proposed; new methods for over-voltage suppression techniques and grounding faults protection are invented. In the normal operation condition of distribution networks, zero sequence current will be injected by PWM inverter to compensate the unbalanced three-phase current, absorb the transient zero-sequence energy and suppress the zero-sequence over-voltage. On the initial stage of grounding faults, zero sequence current will be injected to control the zero sequence voltage and restrain the fault point voltage to zero, and the fault point current will also be restrained to zero, the ground fault arc can thus be 100% extinguished. After a delay, the injection current is superposed with a measurement signal. The magnitude, frequency and phase of the

英文关键词： Distribution networks；Grounding faults；Ground protection；Zero sequence voltage control；Active Inverter