Wind Turbine Mechanical Characteristics and Grid Parameters Influence on the Transient Voltage Stability of a Fixed Speed Wind Turbine

Abstract

This paper describes the effect of wind turbine mechanical characteristic of construction and grid parameters on the transient voltage stability of a fixed speed wind turbine (FSWT) connected to a simple grid. The model of FSWT has been developed in Matlab/Simulink. Using this model, a three-phase fault is applied close to the wind turbine (WT) and cleared by disconnecting the faulted line. The effects of mechanical construction of WT and of grid parameters on the voltage stability of this simple case are evaluated and discussed. The considered parameters are the inertia coefficient of the WT, the short-circuit power at the connection bus, the hub-generator resonant frequency, the wind speed and the reactive power compensation. For each parameter, the terminal voltage and the generator rotor speed for different fault-clearing time are drawn. At last, the terminal voltage and the generator rotor speed obtained for a fifth-order model of the induction generator are compared with those obtained for a third order model. The differences between the two models are discussed. The obtained results will help to understand the transient stability phenomena in wind farms.