基于自适应小波变换与HHT的混合储能容量配置

Hybrid Energy Storage Capacity Allocation Based on Adaptive Wavelet Transform and HHT

混合储能系统能有效缓解风电输出功率强波动性与随机性造成电网频率不稳定问题。本文以蓄电池和超级电容组成的混合储能系统为研究对象,提出了一种混合储能容量配置方法。该方法首先采用自适应小波变换对风电输出功率进行功率一次分配,得到满足条件的并网功率和储能功率。然后采用HHT变换对储能功率进行分解,得到一系列波动功率分量以及各分量的瞬时频率。再根据瞬时频率确定分界频率,将高于分界频率的功率分量分配给超级电容,剩余的功率分量分配给蓄电池。最后根据蓄电池与超级电容各自的储能功率,对储能系统的额定容量与额定功率进行配置。该仿真结果表明,本文采用自适应小波变换与HHT变换能够有效地将风电输出功率进行分解,实现风电输出功率的平抑与混合储能系统的容量与功率配置。

The hybrid energy storage system can effectively alleviate the frequency instability caused by the strong fluctuation and randomness of wind power output.In this paper,a hybrid energy storage system composed of batteries and super capacitors is taken as the research object,and a hybrid energy storage capacity allocation method is proposed.First,adaptive wavelet transform is adopted to perform a primary distribution of the wind power output,and the grid-connected power and energy storage power satisfying the requirements are obtained.Second,HHT transform is used to decompose the energy storage power,and a series of fluctuating power components and the instantaneous frequency of each component are obtained.Third,the cutoff frequency is determined according to the instantaneous frequency,the power components with a frequency higher than the cutoff frequency are allocated to super capacitors,and the rest are allocated to batteries.Finally,the rated capacity and rated power of the energy storage system are configured according to the energy storage power of batteries and super capacitors,respectively.Simulation results show that adaptive wavelet transform and HHT transform can effectively decompose the wind power output,thus realizing the stabilization of wind power output,as well as the capacity and power allocation of hybrid energy storage system.