基于暂态功率的高压直流线路单端量保护

Aiming at the problem of low reliability of traditional single-ended protection for high-voltage direct current (HVDC) lines, by considering the influence of DC boundary, line parameter frequency variation and other factors, this paper studies the transient power fault characteristics of HVDC lines, and puts forward a scheme of single-end protection based on transient power. According to the difference in the frequency band of fault transient power in and out of the positive direction, using the ratio of transient energy between high and low frequency bands, a boundary protection element is built. Considering the limitation of using frequency attenuation characteristics of transient power to distinguish positive and negative direction faults, a directional auxiliary criterion is constructed by using transient power polarity. Combined with the actuating element and the fault pole element, the single-end protection scheme based on transient power is constructed. The simulation results show that the scheme can distinguish the internal and external faults of DC line area rapidly and effectively, with certain resistance to transition resistance and anti-interference ability, and have high reliability.