Multi-constrained optimal control of energy storage combined thermal power participating in frequency regulation based on life model of energy storage

Abstract

The integration of renewable energy into the power grid at a large scale presents challenges for frequency regulation. Balancing the frequency regulation requirements of the system while considering the wear of thermal power units and the life loss of energy storage has become an urgent issue that needs to be addressed. This paper proposes a multi-constrained optimization strategy for coordinating the energy storage combined thermal power frequency regulation (ESCTPFR) control based on the life model of energy storage. Firstly, the paper constructs a multi-dimensional life loss model of energy storage based on charging/discharging times and available capacity. Additionally, a simplified model for the wear of thermal power units is also presented. Based on the fast response time and high response accuracy of energy storage, the frequency regulation loss resistance coefficient of energy storage and thermal power is constructed to improve the enthusiasm of energy storage. Secondly, a two-layer model is proposed to allocate power between thermal power and energy storage, taking into account the frequency regulation cost of the system and State of Charge (SOC) planning. The priority constraints are the system's frequency regulation capacity and the related SOC function with the SOC deviation coefficient used to constrain energy storage power for SOC recovery. Finally, the proposed strategy's cost-effectiveness and effectiveness in reducing frequency regulation loss are validated through simulation experiments based on historical data, along with its ability to recover SOC.