Sizing Optimization And Energy Management Of Microgrid

Rational energy structure is the foundation of economic and social sustainable development. Duo to the serious pollution and decreasing amount of traditional energy resources, there is rapid expansion of distributed generation (DG) especially renewable energy resources (RES), aiming at energy sustainability and harmonious development of society. As the management and access means of DGs, Microgrid has been a focus in electric power research area. The main work of this dissertation is configuration optimization and energy management of Microgrid with emphases on the difference of grid-connected and stand-alone modes as follows:1. A novel configuration optimization method is proposed based on expert system with multi-objectives including life-cycle cost, RES utilization, pollution emission, and stepped safe factor, which represent the economic, environmental and reliable benefits of stand-alone Microgrid respectively. The proposed method is solved by advanced genetic algorithm with the benefit evaluation based on life-cycle simulation. And the optimal configuration is obtained through sensitivity analysis of objectives.2. A novel configuration optimization method is proposed with the objective of life-cycle cost, considering the performance of grid-connected Microgrid such as self-balancing level, power-redundancy level, and tieline and RES utilization. For the RES intermittency, the configuration is progressing gradually by optimization based on stochastic scenarios generated by Latin Hypercube Sampling and Simultaneous Backward Reduction.3. A novel energy management system is proposed based on multi-agent system, including forecast layer, dispatch layer and control layer, to achieve the different goals and tasks in different time scales. Under the proposed EMS, some specific methods such as virtual bidding and dynamic dispatch, and implementation approach of MAS are given according to the PV-Battery-Hydro-Diesel Hybird Microgrid and verified on the PXI-RTDS joint real-time simulation platform.4. A novel energy management system is proposed based on tieline control with the emphasis on the dispatch of energy storage system. The power compensation is firstly obtained by tieline power optimization model or tieline control strategies to smooth the power fluctuation of tieline. And then it is subdivided into segments for energy storage units based on the multi-storage-unit coordinated control strategy to improve the utilization and life-time of energy storage system.5. A novel multi-time-scales coordinated control approach is proposed, which consists of the schedule layer and the dispatch layer, to achieve the coordination and cooperation in long-time scale, and voltage and power flow optimization in real-time scale. Through the coordination of two layers, reserve power is optimized and allocated to eliminate the impact of forecast error. Considering the difference of two operation modes, price incentive is a key point in grid-connected mode aiming at the economic benefit, and load control model is introduced in stand-alone mode to guarantee the safe and stable operation of Microgrid.