Dispatch of main transformer ULTC and capacitors in a distributionsystem

摘要

This paper presents a dynamic programming method for solvingnreactive power/voltage control problem in a distribution system. Thenobjective of this paper is to properly dispatch main transformer undernload tap changer, substation capacitor and feeder capacitors basednforecast hourly loads of each feeder section and primary bus voltagensuch that the total feeder loss can be minimized, voltage profile can benimproved, and the reactive power flow into main transformer can benrestrained. The constraints that must be considered include maximumnallowable number of switching operations in a day for under load tapnchanger and each capacitor, the voltage limit on the feeder, and limitednsecondary bus voltage. To demonstrate the usefulness of the proposednapproach, reactive power/voltage control in a distribution system withinnthe service area of Yunlin District Office of Taiwan Power Company isnperformed. It is found that a proper dispatching schedule for eachncapacitor and under load tap changer can be reached by the presentednmethod