新型虚拟同步发电机分布式主动支撑控制策略

Novel virtual synchronous generator based distributed active-supporting control strategy

面向新能源分布式发电变流器主动支撑控制,提出了一种新型虚拟同步发电机控制策略,来实现有功-频率和无功-电压动态支撑,能够为电网的稳定提供必要的惯量和阻尼,并具备更好的多变流器协同工作能力和对电网的接入能力。首先建立同步发电机的电磁模型,提出虚拟定子绕组概念来调整变流器输出阻抗以满足微网功率解耦条件并实现多变流器间负荷分配,从而设计励磁器来实现无功-电压动态调整。同时结合转子运动方程设计调频器来实现有功-频率动态调整,并提出了虚拟励磁补偿和二次调频策略以消除电压和频率调整静差。最后,利用PSCAD/EMTDC仿真结果以及实验结果验证了所提控制策略的正确性和有效性。

A novel virtual synchronous generator control strategy is proposed for the active-supporting control of renewable distributed generation converters,aiming to achieve the dynamic support of active power-frequency(P-f)and reactive power-voltage(Q-V),so as to provide the necessary inertia and damping for power grid stability,and have better co-operation capability of multi-inverters and access to the power grid.Firstly,based on the electromagnetic model of synchronous generator,a novel concept of the virtual stator winding is proposed to adjust the output impedance of inverters to satisfy the power decoupling conditions of micro-grid and achieve load sharing between converters,and flux controller is designed to achieve Q-V dynamic adjustment.Based on the rotor motion equation,synchronous controller is designed to achieve P-f dynamic adjustment.Meanwhile,virtual excitation compensation and secondary frequency regulation strategy are adopted to eliminate the voltage and frequency adjustment static error.Finally,the PSCAD/EMTDC simulation and experimental results have verified the correctness and effectiveness of the proposed control strategy.