Design and Implementation of Power Plant High-Side Voltage Controller for Coordinated Voltage Control

Abstract

This paper describes the design and implementation of the Power Plant Voltage Controller (PPVC) with an adaptive control which equips at the power plant level with the local high side voltage control. The Power Plant Voltage Controller is part of the hierarchical voltage control system which consists of Tertiary Voltage Control (TVC) at the higher control level and then followed by Secondary Voltage Control (SVC) as a regional controller and Primary Voltage Control (PVC) at the lowest control level to perform the control command. In this control approach, PPVC participates in the lowest control level in the Coordinated Voltage Control (CVC) system. The Power Plant Voltage Control regulators are autonomous controllers that regulate the high-side bus of the power plant while maintaining balanced VAR generation of the individual units and avoiding the dynamic interaction among multiple controlled generators. This paper presents a method of controlling the terminal voltage of the generators at the power plant by utilizing a quasi-steady-state sensitivity to get a control parameter for the PPVC. Using a simple control strategy, an adaptive control can be achieved by periodically calculating the quasi-steady-state sensitivity to update the control parameter, in such a way the PPVC control parameter not only can adapt to the variation of the interconnected network but also with the fluctuation of the load demands.