Research And Evaluation On Economic Planning Methods Of Hybrid Energy Micro-Grid

In recent years, the smart grid concept has gotten a rapid development in China. As a major component of the smart grid, micro-grid attracts increasing attention. However, some key techniques are in need of urgent study, such as micro-grid planning, control and protection, energy management, optimal operation and control, and micro-grid evaluation. Among them, micro-grid planning and evaluation are the most important micro-grid techniques.Currently, micro-grid planning includes location planning and volume planning. The researches on location planning have already been mature in China. Whereas the volume planning of micro-grid still has many problems, such as considering only the power supply side, ignoring consumer side, and considering all the micro-grids are AC micro-grid. Based on the above issues, this dissertation proposes a micro-grid planning method based on direct load control and micro-grid type, so a further study on the economical efficiency of micro-grid can be made. And then an evaluation method based on environmentally friendly micro-grid evaluation system is proposed. The main contents of this dissertation are as follows:(1) A micro-grid planning method based on direct load control is proposed. Load side is considered in micro-grid planning, and power supply side and load side are equally managed and bound. The objective function is the optimal solution in economy of the micro-grid while constraints are the safe and reliable operation of the system. CPLEX 12.6 is used as a computational tool to compute the micro-grid planning results and to explore the influence of increasing upper limit of the controlled load on the results. Simulations prove that direct load control can save investment cost of micro-grid considerably.(2) A micro-grid planning method based on micro-grid type is proposed. During the planning process, the type of micro-grid(DC micro-grid or AC micro-grid) is considered. The objective function is the optimal solution in economy of the micro-grid. CPLEX 12.6 is used to study the influence of ratio of DC loads to total load, ratio of critical loads to total load, network loss, and time-of-use price on micro-grid type, installed capacity of the distributed energy, and investment cost under the proposed objective function. The corresponding micro-grid planning is also presented.(3) A micro-grid evaluation index system based on environmental protection is proposed. The difference among different micro-grid locations is removed by using preprocessing indicators. On the basis of entropy weight method, anti-entropy weight method is proposed to assess the established micro-grid.