Secondary voltage control based on a robust multivariable PI controller

Abstract

Based on the use of a robust multivariable proportional-integral (PI) control algorithm, a new secondary voltage and reactive power control strategy is described. It permits the coordination of discrete and continuous type of reactive power sources to regulate the voltage profile of each region or ‘zone’. Through this coordination, it is able to drive the continuous type of reactive power sources to work near the unity power factor. Results are presented that show the good performance behaviour of this secondary voltage control strategy when it is employed to control the desired voltage profile of the EHV network of IBERDROLA S.A.