Study on Voltage Stability and Control Strategy of Grid-Connected Wind Farm

Abstract

Aiming at the Low voltage ride through capability of doubly-fed wind farm when it is merged into a weak grid, this paper researches the theory of rotor excitation control and proposed an additional control model of DFIG grid-connected rotor flux based on structure decentralization theory. In this model, the Low voltage ride through capability of the doubly-fed wind farm is enhanced by designing the d-Axis and q-Axis adaptive terminal sliding mode controllers for the synchronous rotating coordinate system. Simulation results show that the proposed control model not only can better realize the rapid regulation of reactive power of doubly-fed wind farms, but also improve the ability of the system to resist grid voltage fluctuations, and improve the transient stability of power systems. It has certain theoretical significance and practical application value.