The demand for electric load in recent years has been growing consistently in Taiwan. Besides supplying the load demand, the electricity service of distribution systems has to be reliable to meet the power quality of high tech industry. For a fault contingency in distribution systems, the fault location has to be identified and isolated by operating the boundary line switches. The electricity service for the un-faulted but outaged area has to be restored by transfering the loading to the neighboring feeders. The service reliability of distribution systems, a comprehensive distribution automation system DAS is implemented by integrating the computer master station, the communication system and the remote controlling equipments. The master station of DAS system to perform the function of fault detection, isolation and restoration (FDIR) can accelerate the process of service restoration for fault contingency. To support the topology process of distribution system network, the outage management system (OMS), which has also been installed in all Taipower districts to store the attributes of distribution components, has been applied in this study. The operating mapping system is created to support distribution system operation by retrieving the static data from the OMS system and the dynamic data of line switch status from the real time database (RTDB). By this way, the distribution system network is updated by executing the network topology processor according to the operation of line switches. In this thesis, a rule-based expert system is developed for fault restoration of distribution systems. To assure the proposed switch operation plan for fault restoration can comply with the distribution system operation regulation in Taipower, all of the feeders with open the switch to each feeder are formulated as a supporting group. The reserve capacity of each supporting feeders is used to compare the loading of unfaulted but outaged sections for downstream restoration. Based on the embeded rule base in the application program, the op line switch plan for fault restoration can therefore be derived for dispatchers engineers to restore the service in a short time period. Besides the FDIR function, the application software can also be used to derive the optimal switching operation for loading balance of distribution feeders to enhance the operation efficiency of distribution systems.

With the application of high tech equipments in the industrial, commercial, and residential areas, the enhancement of power quality has become a very critical issue for power utilities. Distribution automation and customer automation will be the most important functions to be implemented. Distribution automation consists of control center, communication system, remote terminal units, and feeder terminal units. The currents, voltages, phase angles, and switch status will be collected by the real time SCADA system. Based on the switch status and connectivity analysis, the distribution network configuration can be identified by executing the topology process. The distribution system planning and optimal operation strategy can be achieved by various application software functions. A multiagent-based distribution automation system is developed for fault detection, isolation, and restoration (FDIR) of distribution systems with JADE platform in this thesis. Remote terminal unit (RTU) agents, main transformer (MTR) agents, feeder circuit breaker (FCB) agents, and feeder terminal unit (FTU) agents of the multiagent system (MAS) are proposed to derive a proper restoration plan after a faulted location has been identified and isolated. To ensure the fault restoration plan can comply with the operation regulation, heuristic rules based on the standard operation procedures of Taipower distribution system are included in the best first search of the MAS. For the fault contingency during summer peak season, the load shedding may be executed and the MAS are designed to restore service to as many key customers and loads as possible. The priority indices of each feeder and service zone are determined according to the key customers within the service territory. A Taipower distribution system with 43 feeders is selected for computer simulation to demonstrate the effectiveness of the proposed methodology in this thesis. It is found that the service restoration of distribution system can be obtained very efficiently by applying the proposed multiagent-based MAS.