随着静态同步串联补偿器(static synchronous series compensator,SSSC)的不断发展及应用,其构成和控制的复杂化对传统超高压输电线路保护提出了挑战,需对含SSSC的输电线路保护原理进行深入的研究。为此,运用串补输电线路的频域模型,分析了串补输电线路故障时故障电流的频率特征。分析结果表明,当串补线路区内、外发生故障时,保护安装处获得的频率分量的含量明显不同。对串补线路区内、外故障时的暂态高频信号频率成分的复杂度进行仿真分析,根据信号复杂度的变化特征,提出一种适应于串补线路的单端暂态量保护新方案。仿真结果表明,该方案性能不受故障类型、故障位置、过渡电阻、故障初始相角和串补度的影响,且具有良好的适应性和灵敏性。
With the continuous development and application of static synchronous series compensator (SSSC), the complication of its structure and control becomes a challenge to the conventional extra-high-voltage transmission line protection, which we have to study further. The paper applies frequency domain model of the series compensated transmission line to analyze the frequency characteristics of the fault current. Analysis results show that the frequency components at the relay-installed place of an internal fault are different from that of an external fault. So the frequency complexity of the transient high frequency signals is studied. According to the changes of the signals complexity, a non-unit transient-based protection for the series compensated transmission line is put forward. The simulation results show that the performance of the proposed scheme is not affected by fault type, fault position, fault resistance, fault inception angle and series compensation degree, and has good adaptability and sensitivity.