【摘要】 针对并网虚拟同步发电机(VSG)在功率指令和电网频率变化时输出有功功率存在超调和振荡的问题，提出基于有功功率偏差前馈的改进阻尼策略.首先，建立VSG并网小信号模型，分析了传统VSG方案振荡问题，并介绍了有功功率微分阻尼方案；然后，在传统VSG摇摆方程输出处引入有功功率偏差前馈环节，通过前馈增益单独调节系统阻尼，并利用闭环极点分布分析了前馈增益对系统稳定性的影响.在此基础上，给出了前馈增益的设计方法.最后，搭建了仿真和实验平台，对所提阻尼策略进行验证.仿真和实验结果表明，该方案提高了系统阻尼，减小了在功率参考和电网频率变化时VSG输出功率超调，改善了系统动态性能，同时不影响稳态下垂特性.更多还原

【Abstract】 To solve the problem of overshoot and oscillation of active power output of grid-connected virtual synchronous generator(VSG) when the power command and the grid frequency change, an improved damping strategy based on active power deviation feedforward is proposed. First, a grid-connected VSG small-signal model is established to analyze the oscillation issue of the traditional VSG scheme and an active power differential damping scheme is described. Then, the active power deviation feedforward loop is introduced at the swing output of the conventional VSG control. The system damping is individually adjusted by the feedforward gain. And the influence of the feedforward gain on system stability is analyzed by a close-loop pole distribution. On this basis, the design method for the feedforward gain is given. Finally, the damping strategy is validated by the simulation and the experiment. Simulation and experimental results show that the method improves the system damping, reduces the VSG output power overshoot when the power reference and the grid frequency change, and improves the system dynamic performance without affecting the steady-state droop characteristics.更多还原