适用于超高压紧凑型线路的突变量保护新方案

A new scheme of variation protection for EHV compact transmission lines

紧凑型线路具有自然功率大、线路走廊小的特点,经济和社会效益显著,是未来输电技术的重要发展方向。超高压紧凑型线路给传统突变量保护带来的一些特殊的技术问题。分析了超高压紧凑型线路的一些特点及其给传统突变量保护带来的影响,提出了适用于紧凑型线路的突变量保护新方案。新方案采用贝瑞隆模型的波动方程精确计算补偿电压,并利用基于小矢量算法的自适应短窗以检测故障和反映故障暂态特征。在此基础上,提出了综合利用自适应短窗和浮动门槛的突变量保护判据。仿真表明,新方案应用于超高压紧凑型线路上是有效的。

The compact transmission line has big natural power and compressed transmission corridor, so it has significant social and economic benefits and is the development trend of transmission technology. As the EHV compact transmission lines on the same tower are quite different from those of conventional lines, their influence on variation distance protection is analyzed. This paper proposes a new scheme of variation distance protection for compact transmission lines. Bergeron model is used in the new scheme to accurately calculate the fault component of compensation voltage. The adaptive short window based on phaselet algorithm is used to detect failures and to reflect the fault feature. Based on that finding, a new algorithm using adaptive short window and floating threshold is proposed. The results of simulations and tests prove that this algorithm possesses excellent performance and is suitable for EHV compact transmission line protection. This work is supported by State Key Laboratory Independent Research Project of Power Transmission Equipment ＆ System Security and New Technology （No. 2007DA 10512712205）.