Examining the Interactions between DG Units and Voltage Regulating Devices for Effective Voltage Control in Distribution Systems

Voltage regulation by means of coordinated voltage control is one of the challenging aspects in an active distribution system operation. Integration of distributed generation (DG), which can also be operated in Volt/VAr control mode, may introduce adverse effects including control interactions, operational conflicts, steady-state voltage variations, and oscillations. Therefore, examining and analyzing the phenomenon (both steady state and dynamic) of the control interactions among multiple Volt/VAr support DG units and voltage regulating devices such as tap changers and capacitor banks would be essential for effective voltage control in active distribution systems. In this paper, the interactions among DG units and voltage regulating devices are identified using their simultaneous and nonsimultaneous responses through time-domain simulations. For this task, an analytical technique is proposed and small signal modeling studies have been conducted. The proposed methodology could be beneficial to distribution network planners and operators to ensure seamless network operation from voltage control perspective with increasing penetration of DG units.