Application of Linear Programming to Relay Coordination in Transmission Power System

• Main Authors: chu, wen shyan, 朱文賢
• Other Authors: Cheng-Fa Yang
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/48077642346132591241

碩士 === 國立台灣工業技術學院 === 電機工程技術研究所 === 85 === During planning the coordination of integer electrical system, all directional overcurrent relays'' settings of network transmission power system not only the direction and coordination of primary and backuprelays, but also relays trip time in the connection of radial systemsthat should be considered. The application of linear programming in this research is to get the settings of overcurrent directional relaysin the network power system. The first step is to digitalize relays'' Time-Current characteristiccurve data in order to be analyzed easily in the computer program. Anequation is simulated by the least square error method. The trip time ofrelays is always expressed by the equation for making use of the linearprogramming to get optimal settings of relays. All overcurrent primary/backup relay pairs in network systems are gotten by graph theorem. A constraint condition in linear programmingis the coordination time between the primary and backup relay, the orderis that the trip time of the backup relay in far bus is larger than thecoordination time plus maximum trip time of all relays to isolate thefault part in radial systems of the bus. The objective function of linearprogramming is the minimum summation of all primary relays'' trip time.Two different network transmission power systems use the above methodsin this research. The results are all the primary relays can trip within0.25 second and all coordination time is between 0.3 second and 1 second.They satisfy the integer protective coordination of network transmissionpower system.