考虑频率特性及储能电池状态的电化学储能参与一次调频控制策略

Electrochemical energy storage participation in primary frequency regulation control strategy considering frequency characteristics and energy storage battery state

针对新能源富集电力系统频率波动的问题和储能电站内部锂电池状态不一致的问题,本文首先分析了储能电站参与电力系统一次调频的控制模型;随后,研究了电化学储能针对不同频率变化特征的虚拟下垂控制模式和虚拟惯性控制模式;接着,基于频率特征和模糊控制,提出了储能控制模式自适应调节方法;为了抑制各储能单元电池健康状态(state of health,SOH)的差异化,本文通过SOH的大小对储能单元进行分组,而后基于各电池组荷电状态(state of charge,SOC)及SOH提出了储能参与一次调频的出力分配方法;基于此,提出了考虑频率特性及储能电池状态的电化学储能参与一次调频综合控制策略;最后,在阶跃负荷扰动和连续负荷扰动工况下,搭建系统模型,进行考虑频率特性及储能电池状态的电化学储能参与一次调频综合控制策略的有效性仿真验证。结果表明,本文所提控制策略在一次调频效果方面优于传统的控制策略,在电池组状态方面,本文所提策略可以减小SOH较差的储能单元的动作深度,提高各储能单元电池SOH的一致性,增加储能电站电池的整体使用寿命。

Herein,the control model of an energy storage power plant participating in the primary frequency regulation of a power system is analyzed to address the frequency fluctuation problem of a new energy-rich power system and the inconsistent lithium battery state inside the energy storage power plant.The virtual sag and inertia control modes of the electrochemical energy storage for different frequency variation characteristics are investigated.An adaptive regulation method of the energy storage control mode is then proposed based on frequency characteristics and fuzzy control.In relation to this,the energy storage units are grouped by SOH size to suppress the differentiation of the battery health state(i.e.,state of health(SOH)) of each energy storage unit.Next,a method of allocating the power output of the energy storage participation in the primary frequency regulation based on the state of charge and the SOH of each battery pack is suggested.Consequently,an integrated control strategy for the electrochemical energy storage participation in the primary frequency regulation considering frequency characteristics and the state of the energy storage cells is presented.The system model is built under the step load and continuous load perturbation conditions.The effectiveness of the integrated control strategy of the electrochemical energy storage in the primary frequency regulation considering the frequency characteristics and the energy storage battery state is verified through a simulation.In terms of battery group state,the proposed strategy can reduce the action depth of energy storage units with a poor SOH,improve the SOH consistency of each energy storage unit battery,and increase the overall service life of an energy storage power plant battery.