This paper reports the results of a detailed study of on-line voltage/var control performed on the Ontario Hydro system. The first part of the study is an asenment of active transmission loss savings obtained by optimizing generator voltages and transformer tape with an Optimal Power Flow program using data from a state estimator. In the second part of the study, the question is addressed of how frequently the generator voltages and transformer tape should be optimized in order to achieve a large percentage of the loss savings indentified in the first part. The study showed that the reduction in active losses is sufficient to justify further effort toward implementing voltage control. The results of the second part showed that for the load curve studied, most of the savings could be achieved with voltage control cycle times of about one hour. A new quadratic programming-based optimal power flow algorithm is also presented which exhibits execution times suitable for real-time applications. Sample execution times are given for various systems which confirm that exact optimal power flow solutions can be obtained in a fraction of the control cycle times suggested in the second part of the study.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.