Short-circuit level control through a multi-objective feeder reconfiguration using fault current limiters in the presence of distributed generations

摘要

Despite the advantages of distributed generations (DGs) in electrical networks, they make some unwanted changes in network short-circuit levels which make new security risks arise. This imposes several new scenarios on the network operation in the presence of DGs. In addition to the mentioned security concerns, reducing network loss is among the objectives constantly sought by system operators. Therefore, this study discusses both the reconfiguration of a distribution network for efficient operation and protection coordination in the form of a multi-objective optimisation problem. The aforementioned objectives include reducing losses and maintaining short-circuit levels under several utilisation scenarios of DGs. Thus, the optimal reconfiguration of the network is simultaneously considered along with the optimal planning of fault current limiters through a two-stage stochastic programming. A fuzzy system is utilised to solve the multi-objective problem and a fuzzy imperialism competitive algorithm is proposed to reach the global optimum. The proposed model is implemented on IEEE 69-bus and a real life 77-bus system. Simulation results confirm that implementing the proposed technique not only reduces power losses, but also maintains a short-circuit level of the network under probable utilisation scenarios which in turn the protection coordination of system is improved.