Study on Power Angle Stability of Wind-fire Hybrid Transmission System Controlled by Virtual Synchronous Machine

Abstract

Wind-fire hybrid transmission system stability has always been a research hot spot, and as the wind turbine control strategy is more and more complex, the stability is more complicated. In recent years, the idea of virtual synchronous machine applied to the control scheme of wind turbines has been popularized, so it is necessary to discuss the power angle stability of wind-fire hybrid system considering the additional control of the wind turbines with the virtual synchronous machine. In this paper, a typical wind-fire hybrid transmission system model is established, and the operating characteristics of the wind turbine are analyzed and the wind turbine model is established. Then, a control strategy of virtual synchronous machine is proposed. At last, the power equivalence function of wind-fire hybrid transmission system is analyzed by Extended Area Equity Criterion (EEAC), and the simulation results in PSASP show that when the receiver is a strong system, the higher the wind-fire ratio, the better the system's angle stability is. The control of the virtual synchronous machine has less effect on the stability of the power angle. When the receiver is a weak system, with the increase of wind power ratio, the power angle stability first increases and then decreases, there is an optimal ratio, and the application of the virtual synchronous machine control can effectively enhance the system's power angle stability, thereby improving the optimal wind-fire ratio.