Research on the optimal configuration of hybrid energy storage

摘要

The randomness and volatility of intermittent energy will make the power grid unstable. And energy storage is connected to the PCC (Point of Common Coupling) in order to stabilize the fluctuations, so that the impact caused by intermittent energy is reduced. The energy density of energy-type storage like battery is high, but the service life will be reduced fast if the storage is charged and discharged frequently. The energy density of power-type storage like super-capacitor is low, but its power density is high and the times of charging and discharging are large. This paper focuses on the optimal configuration of the hybrid energy storage system constructed of batteries and super-capacitors. FFT (Fast Fourier Transform) is for the spectral analysis of intermittent energy output during a control period and the output of the hybrid energy storage is calculated. Taking the cost and service life of batteries and super-capacitors into consideration, the optimization model with the target of minimum annual cost is established. At last the model is solved by PSO (Particle Swarm Optimization) algorithm and is verified in the study case.