Construction of high-reliability distribution network of urban demonstration in Chongqing

Power supply reliability means the power system's ability of sustainable power supply, which is a main index in evaluating the quality of power supply system. In order to improve the reliability of urban distribution network and quality of service, Chongqing Power Corporation made urban core area of 31.5 square kilometers as demonstration area on power supply high-reliability, with the acceptance of the State Grid Corporation in 2014. The average interruption duration is reduced lower than five minutes, which reached the international advanced level. The construction of this demonstration area mainly include reliability evaluation on distribution grid, reliability planning on grid structure, cable non-blackout work, reconstruction on distribution grid, risk analysis on distribution grid operation, production and command platform construction, condition based maintenance technology, construction of standard operation and management system on regional distribution with high reliability, etc. Remote loop closing operation is achieved by data interaction between distribution automation system and the loop closing operation device. Through the information exchange bus, distribution automation system, production management system (PMS), 95598 system, geographic information system (GIS), reliability risk assessment system, online-monitoring system and condition-based maintenance system are integrated together. By using PMS mobile operating platform to process work orders, the efficiency of rushing repair is improved significantly. With the widely application of infrared radiation thermometer and Oscillation Wave Test System (OWTS), not only Condition-based maintenance of distribution network equipment is carried out, but the process of distribution grid maintenance and recovery can be monitored. After the construction of high reliability demonstration area, the average shut down time decreased from 33 min. to 4.557 min., the reliability index (RS-3) increased from 99.96% to 99.9915%, and service quality on power supply and customers' satisfaction also increased significantly, and consequently good society and commercial benefit were made.