电网技术Issue(1)：3850-3856,7.DOI:10.13335/j.1000-3673.pst.2014.01.039
变压器后备保护拒动原因分析与改进
Analysis and Improvement on Mal-Operation of Transformer Backup Protection
摘要
Abstract
Based on a case of mal-operation of backup protection for transformer phase-to-phase faults, this study calculates and analyzes the protection range of low-voltage component, negative-voltage component and overcurrent component. It is pointed out that the sensitivity of overcurrent protection with composite start-up voltage is not enough to reliably clear the fault when a short circuit fault occurs at the remote terminal of a close-in line. To tackle the problem, a method of transformer backup protection based on positive component of compensating voltage is presented. Fault point location is judged with the amplitude and polarity of positive component of compensating voltage, obtained by real-time calculation, and protection scope is automatically adjusted depending on the line length. Installing protection of this kind on the load side of transformers to replace the traditional overcurrent protection with composite start-up voltage can protect the adjacent bus and the whole line. Analysis shows the method is correct and reliable without effect from operational mode of power system, line length, fault point location and transient resistance.关键词
变压器后备保护/复合电压起动的过电流保护/低电压元件/负序电压元件/过电流元件/补偿电压正序分量Key words
transformer backup protection/overcurrent protection with composite start-up voltage/low-voltage component/negative-voltage component/overcurrent component/positive component of compensating voltage分类
信息技术与安全科学引用本文复制引用
姚创,李永丽,张卫正,李仲青,杜丁香,周泽昕..变压器后备保护拒动原因分析与改进[J].电网技术,2014,(1):3850-3856,7.基金项目
国家电网公司重大专项资助项目(SGCC-MPLG028-2012)。@@@@Project Supported by State Grid Corporation of China, Major Projection Planning and Operation Control of Large Scale Grid (SGCC-MPLG028-2012) （SGCC-MPLG028-2012）
