【摘要】 柔性直流电网故障特征复杂，快速可靠识别直流线路故障具有挑战性，为此，文中提出一种基于虚拟功率的柔性直流电网故障保护方案。首先，分析了直流线路在不同故障下线路上限流电抗器虚拟功率变化规律；其次，针对不同故障下限流电抗器虚拟功率的差异性，通过计算限流电抗器虚拟功率变化率识别区内、外故障，并计算正、负极限流电抗器功率积分的比值确定故障极。最后，实验结果表明，所提出的保护方案能准确区分区内、外故障以及故障极，对通信要求低且无需复杂的数据处理，在不同工况下均能够可靠工作，满足柔性直流电网对保护的要求。更多还原

【Abstract】 It is challenging to identify DC line faults quickly and reliably due to the complext fault characteristics of VSC DC power network. Therefore,in this paper a fault protection scheme for VSC DC power gri based on virtual power is proposed. First,the variation of the virtual power of the upper limit current reactor of the DC line under different faults is analyzed;Then,in view of the differences in the virtual power of current-limiting reactors with different faults,faults inside and outside the zone are identified by calculating the variation rate of the virtual power of the current-limiting reactor,and the ratio of the power integrations of the positive and negative current-limiting reactors is calculated to determine the faulty pole. Finally,the experimental results show that the proposed protection scheme can accurately distinguish inside and outside as well as faulty poles,has low communication requirements and does not need complex data processing. It can work reliably under different working conditions and meet the protection requirements of the VSC DC grid.更多还原