The application of the direct self-tuning technique in designing a nodal voltage regulator in power systems

The design of a power system nodal voltage regulator based on the direct self-tuning technique is presented. The approach consists of writing a parameterized model in the regulator polynomials which are determined once the model parameters have been estimated by a constrained recursive least-squares (RLS) algorithm with variable forgetting factor. With this aim in mind a discrete-time linear model which approximates the system dynamics from the regulated node is built-up. The performance of the proposed direct self-tuning control scheme has been analyzed by a accurate numerical time simulation study both in the case of step change in the set-point, and unpredictable unknown load variations.