Simulation Study on Line Backup Protection Fixed Value Optimization of Multi-Infeed DC Transmission System

摘要

Shandong power grid is a typical uhv ac/dc mixed power grid, is also a typical feed in HVDC system, in order to be complicated working condition, the shandong company by optimizing the way of backup protection setting to prevent refusing action, the main cause of multiple dc commutation failure in a row, causing more HVDC pole blocking collapse, leading to power grid in this paper, mainly aimed at distance zero sequence backup protection backup protection period of matching principle and matching principle to carry out the simulation analysis. Simulation results show that de where access will not bring communication relay protection backup segment with the new problems, from a backup using simplified setting principle, when a line of all the main protection loses, may cause the line fault line distance II at the next higher level and at the corresponding level line distance II action conditions at the same time, due to the delay, as possible match problem, the follow-up to carry out special study for this problem.