平抑风光功率波动的混合储能功率分配策略

Hybrid Energy Storage Power Distribution Strategy for Smoothing Wind-Photovoltaic Power Fluctuation

为保证微电网可靠并网,针对风光随机出力引起的有功功率波动问题,利用混合储能系统(hybrid energy storage system, HESS)进行有效平抑。为充分发挥不同类型储能的特性,实现HESS功率的精确分配,提出一种基于鲸鱼优化算法-变分模态分解算法(whale optimization algorithm-variational mode decomposition, WOA-VMD)双层分解的混合储能功率分配策略。采用移动平均算法确定并网功率和HESS所需平抑的波动功率,并利用WOA-VMD分解风光波动功率。考虑到VMD分解余量可能含有丰富信息,再对余量进一步分解,完成HESS的初级功率分配。采用模糊控制优化储能设备的荷电状态(state of charge, SOC),完成HESS功率的二次修正。算例分析表明,所提策略能够对风光波动功率进行自适应分解,实现HESS功率的合理分配,有效平抑风光功率波动,保证微电网可靠并网;并且维持储能SOC处于理想范围,避免储能设备过度充放电,确保HESS安全稳定运行。

In order to ensure reliable connection of microgrid,a hybrid energy storage system was used to effectively suppress the active power fluctuation caused by random output of wind-photovoltaic.In order to give full play to the characteristics of different types of energy storage and achieve accurate power distribution of hybrid energy storage system(HESS),a hybrid energy storage power distribution strategy based on whale optimization algorithm-variational mode decomposition(WOA-VMD)two-layer decomposition was proposed.The moving average algorithm was used to determine the grid-connected power and the fluctuation power required by HESS,and WOA-VMD was used to decompose the fluctuation power of wind-photovoltaic.Considering that the decomposition allowance of VMD may contain rich information,the allowance was further decomposed to complete the primary power allocation of HESS.Fuzzy control was adopted to optimize the state of charge(SOC)of energy storage equipment and complete the second modification of HESS power.Example analysis shows that the proposed strategy can adaptively decompose the fluctuation power of wind-photovoltaic,realize the reasonable distribution of HESS power,effectively suppress the power fluctuation of wind-photovoltaic,and ensure the reliable grid connection.In addition,the SOC of energy storage is kept in an ideal range to avoid excessive charge and discharge of energy storage equipment and ensure safe and stable operation of HESS.