Research on Control Strategy of Supercapacitor-Lithium Iron Phosphate Battery-Flywheel Hybrid Energy Storage System for Mitigating Wind Power Fluctuations Across Multiple Time Scales

Shaobo Yan

doi:10.54097/wzv0sk67

Authors

Shaobo Yan

DOI:

https://doi.org/10.54097/wzv0sk67

Keywords:

Hybrid energy storage system; Wind power fluctuation mitigation; Empirical Mode Decomposition; MATLAB/Simulink simulation

Abstract

Aiming at the problems of reduced power quality and insufficient grid absorption capacity caused by power fluctuations in traditional wind power grid connection, this paper proposes a multi-element hybrid energy storage system composed of supercapacitors, lithium iron phosphate batteries, and flywheel energy storage to mitigate wind power fluctuations across multiple time scales. Firstly, based on the principle of Empirical Mode Decomposition (EMD), the wind power signal is decomposed into three types of fluctuation components with different time scales: high-frequency, medium-frequency, and low-frequency. Secondly, combined with the response characteristics of the three types of energy storage devices (supercapacitors with fast response, flywheel energy storage with high power density, and lithium iron phosphate batteries with excellent energy density), the high-frequency components are allocated to supercapacitors for mitigation, the medium-frequency components are processed by flywheel energy storage, and the low-frequency components are regulated by lithium iron phosphate batteries, forming a multi-time scale coordinated control strategy. Finally, a simulation model is built in the MATLAB/Simulink environment, with 24-hour actual power data of a 20MW wind farm as input, to compare and analyze the mitigation effect and economy of different energy storage combinations. The simulation results show that the proposed hybrid energy storage system can achieve full-time scale coverage of wind power fluctuations, the fluctuation range of the grid-connected power after mitigation is controlled within ±2%, and the life-cycle cost is reduced by 18.3% compared with the traditional "battery-supercapacitor" combination, verifying the effectiveness of the hybrid system in improving the stability and economy of wind power grid connection.

References

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