Analysis and Optimization of System Stability Considering DFIG and PV Connection Methods

The form of connection of wind power and photovoltaic in a grid-connected power generation system affects the stability of the system. In order to ensure the stability of the system, different connection forms should be studied. In this paper, small-signal modeling of wind power and photovoltaics(PV) is developed. Then, the effect of different wiring methods on the small-signal model is analyzed. Equating the effects of the connection method to the corresponding model using a coordinate transformation, the corresponding small-signal models are derived. Based on these models, the impacts of the interactions between wind and photovoltaic are analyzed for different connection methods and the impacts are quantified. The interaction magnitude and eigenvalue sensitivity under different connection forms are utilized to adjust the system parameters and improve the system stability. Finally, the proposed method is tested by the MATLAB/Simulink, which shows that the form of connection affects system stability and the effectiveness of reconciliation methods. In the case of constant wind and PV output, the system small-signal analysis and time-domain simulation demonstrate the effect of the connection method on the system.