风-储孤岛微电网的虚拟同步电机模型预测频率波动抑制

随着我国风力发电系统装机容量的增加，其在电网中的比重也越来越高，高渗透率带来了并网系统频率稳定性问题，对此提出一种虚拟同步电机的多目标预测控制策略。虚拟同步电机控制在频率波动时往往通过设置虚拟旋转方程提供频率支撑，难以达到很好的频率波动抑制效果。为进一步减小频率波动对电网稳定性威胁，考虑到模型预测控制的诸多优点，提出一种基于模型预测控制思想的连续控制集多目标优化方法。该方法利用虚拟同步电机旋转方程建立功率预测模型，可在频率波动情况下预测功率变化。通过设计成本函数和考虑输出约束条件，求解得到最优功率增量，将其用于修改功率指令，使储能电池组在公共接入点处提供更多有功功率，减小系统频率变化。半实物仿真实验证明，该方法可有效降低系统频率波动，提高风-储孤岛微电网系统频率稳定性。

Model predictive control for suppressing frequency fluctuations in virtual synchronous generators for wind-storage island microgrid

With the increasing installed capacity of wind power systems in China,their proportion in the power grid is also growing.However,the high penetration rate of wind power brings about the issue of frequency stability in the grid.To address this,a multi-objective predictive control strategy using virtual synchronous machines (VSMs) is proposed.Currently,VSM control typically provides frequency support by setting virtual rotation equations,but it is difficult to achieve effective suppression of frequency fluctuations.To further reduce the threat of frequency fluctuations to grid stability,this paper proposes a continuous control set multi-objective optimization method based on model predictive control (MPC) principles.This method utilizes the virtual synchronous machine rotation equations to establish a power prediction model,which can predict power changes during frequency fluctuations.By designing a cost function and con-sidering output constraints,the optimal power increment is obtained.This increment is then used to modify the power command,allowing the energy storage battery system to provide more active power at the point of common coupling,thereby reducing system frequency variations.Semi-physical simulation experiments demonstrate that this method effectively reduces system frequency fluctuations and enhances the frequency stability of wind-storage island microgrid systems.