基于功频下垂控制的光伏并网发电系统惯量阻尼机理研究

针对光伏以低惯量、弱阻尼的特征大规模接入电网，给电网稳定性带来不利影响的问题，基于功频下垂控制的光伏并网发电系统，借鉴经典电气转矩分析法，从物理机制层面上分析影响系统惯量、阻尼以及同步能力的作用规律。研究结果表明对于控制参数的影响规律而言，惯量特性主要受功率环的比例系数Kp影响，且随Kp的增大而增强；阻尼特性受频率下垂系数Dp影响比较明显，且随Dp的增大而减弱；同步特性只受功率环的比例积分系数Ki影响，且随Ki的增大而增强。通过仿真验证了理论分析的正确性。

Research on Inertia and Damping Mechanism of Grid-tied Photovoltaic Power Generation System Based on Power Frequency Droop Control

Photovoltaic system with the characteristics of low inertia and weak damping is connected to power grid on a large scale， resulting in adverse effects on the grid stability. Based on grid-tied photovoltaic power generation system with power frequency droop control， the paper analyzes the influence law on the system inertia，damping and synchronization capability according to physical mechanism by using classical electric torque analysis method. The results show that， for the influence law of the control parameters， the inertia characteristics are mainly affected by the proportional coefficient Kp of the power loop and increases with increasing Kp； The damping characteristics are obviously affected by the frequency droop coefficient Dp and weakens with increasing Dp； The synchronization characteristics are only affected by the proportional integral coefficient Ki of the power loop and enhances with increasing Ki. The correctness of the above theoretical analysis is verified by simulation.