The Optimal Strategy Research Of Distribution Network Reconfiguration Considering Interval Uncertainty Of Renewable Energy And Loads

With the changing of global environment, renewable and clean energy resources including wind and solar energy are getting more and more attention in power system. But the output of wind and solar energy is greatly influenced by the weather and environment and has great volatility, which brings about lots of problems to the control and operation of power system. As an important measure to optimize the operation of power system, network reconfiguration is widely applied to improve the reliability and economy of the power system. With the access of renewable energy, it is difficult for the traditional methods of network reconfiguration to get the optimal solution. Thus, it is of great practical meaning to study the strategy for network reconfiguration considering the uncertainty of renewable energy. The specific work is as follows:Interval power flow is used in distribution network considering the uncertainty o f renewable energy, which provides fundamental basis for interval optimization model of distribution network reconfiguration. Forward-backward sweep method is adopted in interval power flow, and the uncertainty of renewable energy is included using int erval arithmetic. The values of transmission loss and voltage of it are compared to tha t of the repeated power flow which simulates the uncertainty of renewable energy by choosing random value. The result of the simulation shows that it is valid to include the uncertainty of renewable energy in power flow using interval arithmetic.The interval optimization model of distribution network reconfiguration which aims at reducing the cost is built. The objective function of the model is the cost of power loss and switch operation, which is optimized by DE algorithm. As the increase of the uncertainty of renewable energy, the center point of cost can keep stable, while the radius of voltage and cost interval is not efficiently reduced in the single objective model, which provides the background and theoretical foundation for the multi-objective interval optimization model.The multi-objective interval optimization model of distribution network reconfiguration and an adapted algorithm are proposed. The objective functions of this model include economy and voltage quality of the power system. By the multi-objective optimization method, the robustness and expected mean value are both improved, which minimize the effectiveness of the volatility of inputs. And it meets the requirements of economy and safety of the power system and satisfies diverse preferences. The model is optimized by the improved Multi-Objective Differential Evolution, and the improved multi-objective differential evolution shows superiority in convergence and distribution.In conclusion, the research is focused on optimizing the strategy for network reconfiguration considering the uncertainty of renewable energy. Two interval optimization model of distribution network reconfiguration are proposed and established, and the Multi-Objective Differential Evolution is adapted to optimize the multi-objective problem, which provides references for distribution network optimization under backgrounds of uncertain inputs.