Novel strategy of updating Volt/VAr control set-points for eliminating interactions between different voltage regulating devices and DG units

Abstract

In modern medium voltage distribution grids, voltage and reactive power (Volt/VAr) control can effectively be achieved using the time delayed responses of on-load tap changer, line voltage regulators, capacitor banks and distributed generation (DG) units. The timely coordination among different Volt/VAr control (VVC) devices can be assured through online control processes and updating the control parameters (i.e. set-points) of VVC devices. This is essential for efficient operation of the distribution grids while achieving steady-state voltage recovery and other control objectives such as loss minimisation; as the control interactions among VVC devices and Volt/VAr support DG units caused by poor coordination can lead to operational conflicts. In this article, a novel control approach is proposed for updating VVC set-points for eliminating operational interactions between different voltage regulating devices; thereby, minimising power losses in a network. The proposed strategy has been tested on a practical distribution system derived from the state of New South Wales, Australia, and the simulation results are reported. The results have demonstrated that the interactions among VVC devices and Volt/VAr support DG units can be avoided while minimising power losses, with the implementation of the proposed strategy.