Optimal Scheduling Models And Algorithms Of Integrated Microgrids

The microgrid is a distribution system that integrates the increasing number of renewable energy resources, storage systems and controllable loads to support a flexible and reliable renewable energy distribution. Currently, microgrids can be used for a broader range of applications in the rural area and disaster restoration efforts, and enable higher efficiency in managing uncontrollable renewable energy resources such as wind and solar. However, there are operational and technological problems using the microgrids that need to be resolved so that the entire electrical community will receive benefits of having clean and high-quality power with lower cost. We have identified three optimization problems in this dissertation: 1) a operational problem to find optimal electrical power price and quantity when microgrids should trade (sell/buy) surplus/lacking power with distribution system, 2) a technological problem to use the minimum cost to deal with operation uncertainties such as generators’ output and operation mode change when the operator schedules a microgrid, and 3) a managerial problem to co-optimize the energy and ancillary service interaction between microgrids and power system. This work will provide insights into these problems and give some practical solutions. First, we provide a solution of designing a competitive decentralized distribution system. In addition, we identify a clear definition of the role that microgrids can play in this electrical market so that the microgrid operators can achieve maximum benefits. Second, we provide a stability opportunity risk index to evaluate the effects of microgrid operator managing the scheduling uncertainties. Then, a co-optimization scheme is developed for microgrid operator to schedule ancillary service from external resources (distribution system) and internal resources (disputable units). Third, a transactive management scheme provides a decentralized solution by constructing a boundary between the responsibility of microgrid and distribution system. By having a bi-directional energy and ancillary service scheme between two entities, the efficiency of market operation is improved.