Multitime Scale Coordinated Scheduling for the Combined System of Wind Power, Photovoltaic, Thermal Generator, Hydro Pumped Storage, and Batteries

Grid connection of intermittent renewable energy, such as wind power and photovoltaic, results in challenges of keeping power balance for power system operation. In order to solve this problem, this article proposed a multitime scale coordinated scheduling model for the combined system of wind power-photovoltaic-thermal generator-hydro pumped storage-battery (WPTHB) by taking advantages of their complementary operation characteristics. The scheduling model is composed of three time scales: the day-ahead scheduling, the 1-h ahead scheduling, and 15-min ahead scheduling. 1) In the day-ahead scheduling, based on the 24-h ahead forecast data of wind-photovoltaic power and load demand (WPL), the optimal power outputs of thermal power units are solved from a mixed-integer linear programming model to achieve the minimal operation cost of thermal units. 2) In the 1-h ahead scheduling, based on power output of thermal units optimized in the day-ahead scheduling and the hourly forecasted WPL, the hydro-pumped unit power outputs are optimally dispatched to minimize their operation cost. 3) In the 15-min ahead scheduling, based on day-ahead optimal power outputs of thermal units and the 1-h ahead optimal outputs of pumped storage, the battery optimal power generation is obtained from an ac optimal power flow model solved by MATPOWER. The simulation of the New England system has validated that the proposed multitime scale coordinated scheduling model could fully explore the distinguished power regulation speed and capacities of thermal power units, hydro-pumped storage, and batteries to effectively track WPL variations and achieve system economic operation simultaneously.