Research on the Optimization Method of Capacity Configuration of DC Microgrid

摘要

For the uncertainty brought by the connection of new energy to the grid, the research on the optimization of the capacity allocation of the DC microgrid becomes very important. The optimal configuration of DC micro-grid is the key to ensure the stable and economic operation of microgrid. This paper takes multi-layer optimization as the main idea to optimize the capacity configuration of the micro-grid. Firstly, the economic optimal solution of the system is obtained by enumeration method. With the lowest total cost of the project as the objective function, and the sensitivity analysis conditions of diesel price and new energy efficiency are taken as the sensitivity analysis conditions to obtain the economic optimal scheme and conduct preliminary analysis. Secondly, by taking the first-layer optimization results as the initial solution, particle swarm algorithm (PSO) is adopted to calculate and find the optimal scheme of system performance by taking economic conditions, new energy utilization rate as the constraint conditions, and the minimum sum of load power shortage rate and energy surplus rate as the objective function. The multiobjective problem is transformed into a single-objective problem by the weighted average method, and used to obtain the optimal solution. Finally, droop control method is introduced for the system to verify the stability of the system. This shows that the system can maintain power balance and provide correct guidance for stand-alone DC microgrid capacity design.