Combined system for reactive power control in wind farms

Operation of wind turbine installations may affect the steady-state voltage in the connected network. The voltage fluctuations imposed by the wind farm will depend on the characteristics of the grid. This paper presents a combined system of a capacitor, a thyristor controlled reactor (TCR) and a small-rated active filter (PWM-VSI) whose goal is to obtain a regulation of reactive power in wind farms with a generation of harmonic currents very reduced. The electrical analysis and filtering characteristics are discussed theoretically and several situations are simulated.