Optimal scheduling method of Distributed Generators and plug-in electric vehicle for reconfigurable distribution systems

Distributed Generators (DGs) have a huge economical and environmental potential, especially if based on Renewable Energy Sources (RESs). However, high penetration of DGs into distribution systems can cause voltage deviations beyond the statutory range, and can reverse power flow toward the substation transformer. Consequently, DGs can increase energy losses if not well controlled. Coincidentally, the demand on Plug-in Electric Vehicles (PEVs) is increasing and will be well-spread in distribution systems in the near future. Thus, the aggregated power of the PEVs will play an important role in the power system. However, the mismanagement of this potential power may cause serious losses. Thus, a power scheduling method of DGs, PEVs and tap transformers is proposed in this paper to reduce the total energy losses in the distribution systems. In order to achieve the lowest possible total loss, reconfiguration of the distribution system is considered every hour during the optimization. To show the effectiveness of the proposed method, a one day-ahead power and configuration schedule is generated using Particle Swarm Optimization and based on the weather and load demand predictions. The total energy loss expected from the generated optimal schedule considering the system reconfiguration is then compared to other losses obtained from optimal schedules generated for different fixed configurations. Other important objectives are also considered such as keeping the voltage within the statutory range and prevention of reverse power flow to protect the substation transformer.