Study on the Hierarchical Control Algorithm of SMES-BESS Hybrid Energy Storage Based on VMD and Fuzzy Control

In China, the installed capacity of renewable energy sources such as wind and photovoltaic power has ranked first in the world for consecutive years, and new energy has become a core driver of energy structure transition. However, the strong volatility and intermittency of new energy output seriously affect the safe and stable operation of the power system, and high-efficiency energy storage technology is the key to solving this problem. Focusing on the short-term high-power charging and discharging characteristics of high-temperature superconducting magnets (SMES), this study proposes a Hybrid Energy Storage System (HESS) that combines SMES with Battery Energy Storage Systems (BESS) to enhance the short-term power support capability of electrochemical energy storage. Variational Mode Decomposition (VMD) is introduced to establish a multi-level power allocation method, which addressing issues such as mode mixing, end effects, and low decomposition efficiency that are prone to occur in traditional Empirical Mode Decomposition (EMD), and optimizes the internal power allocation of HESS and the State of Charge (SOC) management of energy storage units. A PI controller architecture with power outer loop and current inner loop for SMES and BESS is designed to enabling hierarchical complementary regulation of power and energy between the two components. A simulation model is built using MATLAB/Simulink to verify the feasibility and effectiveness of the proposed algorithm. Taking the power fluctuation suppression of wind farms as an example, the practicality of the scheme is further confirmed, demonstrating its promotion potential in multiple application scenarios.