The grid connection of intermittent energy sources such as wind power and photovoltaic power generation brings new challenges for the economic and safe operation of renewable power systems. To address these challenges, a multi-time-scale active power coordinated operation method, consisting of day-ahead scheduling, hour-level rolling corrective scheduling, and real-time corrective scheduling, is proposed for the combined operation of wind-photovoltaic-thermal-hydro power and battery (WPTHB) to handle renewable power fluctuations. In day-ahead scheduling, the optimal power outputs of thermal power units, hydro-pumped storage units, and batteries are solved with the purpose of minimizing the total power generation cost. In hour-level rolling corrective scheduling, the power output plan of thermal power units and pumped storage units is modified to minimize the correction cost based on the on-off state of thermal power units determined in day-ahead scheduling. In real-time corrective scheduling stage, the feedback correction and rolling optimization-based model predictive control algorithm is adopted to modify the power output of thermal power units, hydro-pumped storage units, and batteries optimized in hour-level rolling correction scheduling, so as to ensure the economy of the correction plan and the static security of system operation. Finally, simulation results demonstrated that the proposed method can accurately track system power fluctuations, and ensure the economic and security operation of a multi-energy-generation system.
IntroductionRenewable energy sources such as wind and photovoltaic power generation have experienced explosive growth, and their natural intermittence brings new challenges for the economic and safe operation of renewable power systems. To handle uncertainties of renewable energy sources [1,2], an effective scheduling method for a multi-energy complementary generation system [3,4] is pressingly needed to alleviate the volatility of renewable power generation [5].At present, there are a few studies for the combined operation of a multiple-source power generation system [6][7][8]. A hybrid scheduling optimization model was proposed in [9] to manage the demand response for cascaded hydropower and wind-photovoltaic power stations. An integrated dispatch model with a multi-objective function was presented in [10] for optimizing the wind-photovoltaic-storage power generation output under generalized load fluctuations. In [11], a wind-hydro-thermal unit combination model was established for a day-ahead scheduling plan, and afterward the model was solved by variables separation and a piecewise linear strategy to manage the hydraulic production capacity curve. An optimal operation model for a large-scale