Mid-long term optimal dispatching method of power system with large-scale wind-photovoltaic-hydro power generation

Wind power, photovoltaic power and hydro power have been used as clean energy power generation widely around the world for low generation costs and considerable environmental benefits. However, the strong random fluctuations of new energy make the pressure of system peaking and frequency modulation increase, and the safety and reliability of the system decline when large-scale wind-photovoltaic-hydro power integrated to the grid. It's even more difficult to predict wind-photovoltaic power output especially in the mid-long term optimal dispatching. This paper analyses the output characteristics of wind power, photovoltaic power and hydro power in mid-long periods, and generates power output curve of typical day in every month from historical data. Then we establish the mid-long term optimization model of power system with wind-photovoltaic-hydro power which aims to make the total cost of the system operation optimal. It can determine the optimal working position and capacity of each power plant in the daily load curve basis of taking the characteristics of various types of power plants into account and making full use of renewable energy resources. The result of the test system verifies the rationality and feasibility of this model, and gives guidance to the mid-long term dispatching of wind-photovoltaic-hydro power system.