Voltage Sensitivity to Capacitor Switching on an Existing Fixed Speed Induction Generator Wind Farm

Switched capacitors at wind farms employing fixed speed induction generators are intended to provide reactive power support to control and maintain the voltage at the point of common coupling (PCC) within acceptable operational values. Malfunction of the capacitor switching control may lead to voltage depression and, subsequently, to tripping of turbines which could create additional transient power quality disturbances. This paper presents results of simulations of voltage regulation problems of an existing wind farm on the Bonneville power administration (BPA) system where voltage regulation problems have led to the study of possible dynamic voltage compensation schemes to minimize the problem. SCADA data for real and reactive powers and voltage have been analyzed against results from simulation models to verify the behavior and confirm the mechanisms associated with the voltage regulation problems. Other aspects associated with the high fidelity modeling of the wind farm and issues about the sizing of a possible dynamic voltage controller are investigated.