The Study Of Power Network Planning And Uncertain Factor Processing

Transmission expansion planning plays a critical role in power system planning. According to the growth of future generation and load demand in the planning period studied, the goal of transmission expansion planning is to select new transmission lines based on existing transmission network to ensure the secure and economical operation of power system. A reasonable transmission structure is the basis of operating safely, reliably and economically. With the rapid development of nationwide transmission network, new criteria and approaches are required for transmission expansion planning.In this dissertation, the present status of transmission planning is reviewed from various viewpoints and the new requirements of transmission planning resulting from development of electricity markets are discussed. The thesis points out that the security and flexibility of transmission system should be considered in the objective function except for the economy. With systemic research, transmission expansion planning models and the methods to solve them are put forward.The heuristic method is used wildly because of its simplicity, visualization and easy for people to take part in optimization decision. In this thesis, it gives samples to testify the availability of this classical arithmetic and then points out a heuristic method of transmission network planning which takes into account N-1 security, in this method, it combines heuristic method and N-1 security principle, adopting DC Power Flow model to add and delete line to transform network configuration automatically and creating final network expansion planning. It is simple and rapid, at last this thesis uses a sample to testify this method and the result shows it can give a planning which meets practical engineering needs.The significance of the flexibility network planning research is given, according to the characters of the uncertain factors. This thesis sets forth the feasibility and the advantage of the unascertained number in the aspect of solving the problem of the uncertain factors. On the base of it, this thesis attempts to use unascertained number to describe and deal with the uncertain information then found the model for transmission expansion planning.