基于多频带能量的高压直流输电线路单端暂态电流保护

分析高压直流输电(High Voltage Direct Current，HVDC)线路边界和线路的频率特性，直流线路边界和直流线路对故障暂态电流信号高频分量都具有衰减作用。一些文献据此利用高频分量作为单端暂态保护的判据，但是对于长线路来说，直流线路对于高频分量的衰减可能会大于直流线路边界对高频分量的衰减作用，这样可能会造成保护误动作。进一步分析发现，直流线路边界对于低频分量具有放大作用，直流线路对于低频分量具有衰减作用。因此提出一种基于多频带能量的HVDC线路单端暂态电流保护新原理。利用0~1.25 kHz低频带能量、高频带和低频带能量比来区分区内、区外短路故障，故障性雷击和非故障性雷击，利用正极和负极的能量比判别故障极。

HVDC transmission line protection based on single-ended transient current using multiband energy

The frequency characteristics of HVDC transmission line and line boundary are analyzed, the fault transient high-frequency current signal will be weakened through line boundary and DC line. The high-frequency components are used as a criterion for single ended transient protection in some literature, but for long lines, DC line for attenuation of high frequency components may be larger than line boundary, which may cause malfunction protection. Further analysis shows that physical boundary has an amplification effect on low frequency components, and DC line has an attenuation effect on low frequency components. Based on multiband energy, a new principle of single ended transient current protection for HVDC transmission line is proposed. The identification criterion of internal and external faults, lightning stroke fault and non lightning stroke fault are based on the energy of 0~1.25 kHz low frequency, energy ratio of high frequency and low frequency, the fault line is selected by the energy ratio of the two lines.