Energy Storage Allocation of Thermal Power Plants to Improve Second Frequency Regulation Performance

With the large-scale integration of renewable energy sources, the demanding of secondary frequency regulation task has been increasing. As a result, conventional thermal power plants that bear the secondary frequency regulation task are no longer able to meet the requirements of the power grid. Energy storage system (ESS) has become a suitable source for frequency regulation, which can effectively assist thermal power plants in frequency regulation. This paper establishes a thermal power plant-energy storage integrated system and propose a coordinated control strategy for improving the secondary frequency regulation performance. With proposed control strategy, the numerical characteristics of AGC signal, power and state of charge of ESS are calculated based on the theory of stochastic signal, according to which the rated power and capacity of ESS are allocated. Finally, MATLAB/Simulink is used for simulation to verify the effectiveness of the control strategy and the rationality of the allocation results.