Abstract The phasor information of busbars other than the busbar linked to the relay is now available by means of phasor measurement unit(PMU). Therefore, it is a significant issue on utilizing this type of information to improve the operating performance of protection. To overcome the problems caused by the conventional fault-component based distance relay, such as when a external earth fault occurred while the phase of both power system varied greatly, a novel implementation of fault-component based distance protection by adjusting the threshold based on the real-time parameters of the power system is put forward. The limitations of the conventional solutions are discussed at first Then, the boundary conditions of the existing criteria are determined and proved in theory. A floating threshold based novel criterion is therefore proposed to sovle this problem. It is verified with ATP simulation tests that this criterion is stable when experiencing the external faults. Meanwhile, it can discriminate the internal faults under the extreme conditions. Further, the new criterion and the existing criteria are compared with each other, and their advantages and disadvantages are highlighted. These criteria can reinforce with each other in terms of protection performance. Finally, an effective comprehensive scheme to improve the reliability of fault-component based distance relay is proposed.
Lu Wenjun,Lin Xiangning,Huang Xiaobo等. A Scheme of Adaptive Fault Component Distance Protection Using Float Threshold[J]. Transactions of China Electrotechnical Society, 2009, 24(6): 160-165.
2009, Vol. 24 
