Research on Automatic Adjustment Algorithm of Line Protection Setting

With the changing of power system operation state, line protection setting should be renewed in time. However, the changing of protection setting in large quantities will increase the mismatch possibility of protections. In order to farthest avoid it from being a hidden fault source which threats the stable operation of power system and improve reliability of relay protection, an automatic adjustment algorithm of line protection setting is proposed. The algorithm is easy to be implemented by computer. Through setting applicability judgment and setting optimization, protection setting can be adjusted automatically on the premise of meeting the requirement of selectivity and sensitivity. Examples show that the proposed algorithm can greatly reduce the number of protections whose setting should be changed in comparison with traditional method, and improve the performance of protection setting, which can solve the problem of setting adjustment well after power system operation state changes, and has good application value.