A real-time load response method for thermo-electrical energy storage systems based on internal-external attribute matching and frequency division

To address the real-time load response bottlenecks caused by the inherent thermal inertia of thermal energy storage (TES), this paper proposes an innovative power response method by matching internal energy storage processes with external power loads. The response time of a TES system to electrical load variations is reduced from minute-scale scheduling to the 5-s-scale response. First, a second-scale dynamic response model of thermo-electrical energy storage system is established, which accurately captures the dynamic changes of both internal and external characteristics of the energy storage system. Second, a comprehensive performance comparison map is developed. This map reveals the diverse energy storage performance of multi-type energy storage systems under varying external power and guides the rational matching of external power loads. Third, a frequency-division method based on Fourier transform is proposed to precisely match real-time power fluctuations. This allows the inherently large-inertia thermal storage to effectively respond to low frequency components of real-time load. Finally, the effectiveness of the proposed method is validated through simulation and virtual-real integrated microgrid experiments. The results demonstrate that the system achieves real-time response within 5 s, while effectively maintaining the high-efficiency operating range of energy storage and reducing the microgrid voltage deviation by 2.38%. This work provides a valuable reference for the high-efficiency integration of TES into modern power systems, breaking the barrier that limited TES's poor support capability to microgrid.