虚拟同步机并网系统功率动静态耦合特性分析及解耦方法OA

There is a coupling phenomenon between active power control and reactive power control in a grid-connected system controlled by virtual synchronous generator(VSG)technology,which increases the oscillation amplitude and settling time of the system's dynamic response.In severe cases,shutdowns may be triggered due to voltage and current limit violations.To resolve the problem,the power coupling matrix model in the dq reference frame and the power balance equations for the VSG grid-connected system are first established,which are employed to analyze the dynamic and static coupling characteristics of the system power.Then,for the dynamic coupling characteristics in the main circuit of the system,the voltage and power angle feed-forward decoupling terms are designed and used for dynamic compensation in the form of decoupling functions,thereby effectively eliminating the dynamic coupling phenomenon caused by power adjustment.Secondly,the virtual electromotive force variation component caused by active power adjustment is calculated to compensate for the voltage droop feedback,reducing its static coupling effect on reactive power.Finally,simulation and experimental results show that the proposed decoupling control method can achieve effective decoupling under the operating conditions of power reference step changes,grid frequency disturbance,grid voltage disturbance,and large power angle,improving the dynamic and static response performance of the system.