含逆变型分布式电源的配电网正序和商阻抗纵联保护

逆变型分布式电源(inverter interfaced DG，IIDG)的接入，改变了原配电网保护动作特性。基于此，提出一种基于正序和商阻抗的纵联保护新原理，利用故障时线路两端电压正序分量之和与电流正序分量之和的比值，来判断线路上是否发生故障。在区外发生故障时，该比值反映输电线路对地的容抗值，其模值较大；区内故障时，忽略线路阻抗时，该比值反映2倍过渡电阻或4倍过渡电阻，其模值相对较小:据此可以区分线路上的区内与区外故障。仿真结果表明，新原理特征量明显，容易整定，不受分布式电源的控制策略及出力的影响，抗过渡电阻能力强。

Pilot Protection of Positive Sequence Summation Quotient Impedance for Distribution Network with Inverter Interfaced Distributed Generator

Due to the introduce of the inverter interfaced distributed generations (IIDG), the original protection of the distribution network has been changed. Based on the ratio between the sum of two terminals positive sequence voltage phasor of the transmission line and the sum of two terminals positive sequence current phasor of the same line, which is defined as positive sequence summation quotient impedance, a new positive sequence line pilot protection principle is proposed. When an outer fault occurs, the positive sequence summation quotient impedance reflects the capacitance impedance of the line, and its value is large. When an internal fault occurs, if the line impedance is ignored, the ratioreflects 2 times the transition resistance or 4 times the transition resistance, and its value is relative small. When the faults occurs in outer or internal, the amplitude of the positive sequence component integrated impedance varies obviously and therefore, the internal and outer faults on the line can be distinguished. Simulative results show the new principle has strong resistance to transition resistance and obvious characteristics and is easy to tun and is not affected by the control strategy and the generated power of the distributed power supply.