Integrated optimization of distribution network incorporating microgrid based on co-evolutionary game algorithm

Previous studies of distribution network (DN) and microgrid focused mainly on the optimization of either the microgrid dispatch or DN power loss. Microgrid economic dispatch approach normally does not support DN, and DN usually does not take microgrid into consideration. However, microgrid and DN have mutual influences and restraints in grid-connected operation. This paper proposes an integrated optimal method that takes care of both microgrid and DN. Microgrid and DN, as two objectives that need to be optimized at the same time, have some conflicts of benefit. In order to solve the problem, a co-evolutionary game algorithm (CGA) is proposed in which microgrid and DN are modeled as game participants. Benefit models for microgrid and DN are established respectively and fuzzy mathematics method is applied to generalize the functions. Moreover, a maximum risk rate based dynamic optimal sub-model considering the randomness of distributed energy is established to make dynamic adjustments in CGA. The simulation results show that the final optimal stable strategy (OSS) allows the entire network to achieve the best operation. Comparison with multi-objective optimization method is also carried out.