摘要
传统的直流输电线路行波保护易受故障电阻的影响,作为后备保护的纵联差动保护动作速度慢,而且需两端数据同步,对此提出一种基于S变换的高压直流线路纵联保护新方法。理论分析表明,当故障发生在保护安装处的正方向时,保护检测到的电压和电流突变量的极性相反,而反方向故障时,二者的极性相同。根据此特征,提出利用S变换相角差的方法来识别两者的极性,进而判断故障的方向。此外,对于双极输电系统的单极接地故障类型,可根据两极电压突变量的S变换零频暂态能量和的比值差异实现故障选极。仿真结果表明,所提方法在各种故障情况下都能够有效地识别区内外故障、故障极以及雷击干扰,灵敏度高,可靠性强。
The effectiveness and reliability of traditional traveling wave protection of HVDC line is affected by fault resistance, while the current differential protection as backup protection has the disadvantages of slow operation speed and dependance on data synchronization. This paper proposed a pilot protection method for HVDC transmission lines based on S transform. Theoretical analysis shows, for a fault occurring on the forward direction of the protection, the polarities of the fault components of voltage and current detected are opposite, but for a backward direction fault, they are the same. According to such characteristics, a new method based on S transform angle differences to identify the polarities of the fault components of voltage and current to distinguish the fault direction was proposed. In addition, for a pole-earth fault in a bipolar HVDC system, the faulted line can be determined by ratio differences of the sum of S transform zero frequency transient energies of the fault component of voltage on two lines. The simulation results show that the proposed method can effectively identify the internal and external faults, the faulted line and lightning disturbance in different fault conditions with high sensitivity and reliability.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2016年第5期1228-1235,共8页
Proceedings of the CSEE
基金
国家自然科学基金项目(51277114)~~
关键词
高压直流输电线路
电压电流突变量
S变换
故障极
纵联保护
high voltage direct current （HVDC）transmission line
fault components of voltage and current
Stransform
faulted line
pilot protection
