Research on Power Distribution of Hybrid Energy Storage for Direct Drive Wave Power Generation System to Stabilize Power Fluctuations

The power in the direct-drive wave power generation system is intermittent and fluctuating, and the electric energy it generates cannot meet the power quality requirements of the load directly. In order to stabilize the output of the wave generator, hybrid energy storage can be added to its output side to achieve voltage and power stability. A perfect control strategy of the hybrid energy storage device can reduce the number of charging and discharging of the energy storage device, so as to effectively extend the service life of the energy storage device. This paper proposed a hybrid energy storage power distribution strategy for the wave power system to stabilize power fluctuations, built a miniature direct-drive wave power DC system model, and used the hybrid energy storage to stabilize its output voltage. In this paper, based on the EMD (Empirical Mode Decomposition) method, the Hilbert transform was introduced to obtain the real-time frequency domain relationship of the power signal, and the minimum frequency aliasing method was adopted for power distribution accordingly. After that, for the purpose of stabilizing the DC bus voltage, an energy management strategy considering the state of charge (SOC) of the energy storage device and a reasonable crossover point was designed, and a simulation model was built in Matlab\Simulink to verify and analyze it.