基于动态任务系数的储能辅助风电一次调频控制策略

Control Strategy for Dynamic Task Coefficient Based Primary Frequency Regulation of Wind Power Assisted by Energy Storage

针对高风电渗透率下的频率恶化问题,提出一种基于动态任务系数的储能参与一次调频的综合控制策略。首先,在惯性响应阶段采用虚拟惯性控制和虚拟下垂控制;在一次调频阶段采用虚拟下垂控制和虚拟负惯性控制。其次,基于双曲正切函数分别构建适应于惯性响应阶段和一次调频阶段的动态任务系数模型,根据频率偏差变化率和频率偏差的变化,动态调整一次调频过程中虚拟惯性控制、虚拟负惯性控制及虚拟下垂控制所承担的调频任务比例。根据储能荷电状态(SOC)和系统最大频差来调整负惯性控制单位调节功率,从而加速频率恢复;在虚拟下垂控制的基础上,提出变虚拟下垂控制单位调节功率方案,使虚拟下垂控制单位调节功率随SOC自适应变化。最后,以某区域电网为例,在阶跃负荷扰动和连续负荷扰动工况下验证了所设计策略的有效性。

Aiming at the frequency deterioration caused by the high penetration of wind power,a comprehensive control strategy based on dynamic task coefficients is proposed for energy storage to participate in the primary frequency regulation.Firstly,virtual inertia control and virtual droop control are used in the inertia response stage,while virtual droop control and virtual negative inertia control are used in the primary frequency regulation stage.Secondly,based on the hyperbolic tangent function,the dynamic task coefficient models suitable for the inertia response stage and the primary frequency regulation stage are constructed,respectively.According to the frequency deviation change rate and the change of frequency deviation,the proportion of frequency regulation tasks undertaken by virtual inertia control,virtual negative inertia control and virtual droop control during the primary frequency regulation process is adjusted dynamically.The unit adjustment power of negative inertia control is adjusted according to the state of charge(SOC)of energy storage and the maximum frequency difference of the system to accelerate frequency recovery.Based on the virtual droop control,a scheme with variable unit adjustment power of virtual droop control is proposed to make the unit adjustment power of virtual droop control change adaptively with the SOC.Finally,taking a certain regional power grid as an example,the effectiveness of the designed strategy is verified under the conditions of step load disturbance and continuous load disturbance.