Optimal control of capacitors on distribution feeders

Capacitors have long been used on distribution feeders for, among other things, voltage profile management, power factor correction and loss reduction. The basic choice has been: fixed banks; or switched banks with a variety of local controls. Centralized Volt/VAR control allows for “optimal” feeder conditioning for loss reduction and demand reduction. To be effective, both local and centralized control strategies must incorporate the right types and settings to produce the most benefit over the load cycle. To address this issue, the distribution utilities of the DSTAR consortium recently commissioned a comprehensive study of capacitor control strategies for distribution feeders. This paper presents the study approach and discusses some findings from the work. The field data leveraged simulation method used in this study is also suitable for assessing the impact of a variety of load and generation technologies (such as solar PV) on distribution operation.