Robust fallback sheme for the Danish automatic voltage control system

Voltage Control in the Future Power Transmission Systems

“…Fallback scheme As the function of REPORTs in Italian AVC system [40], a fallback scheme is expected to be implemented in the Danish AVC system, in case a certain substation loses the telecommunication to the control center or several stations are isolated from the main grid [52]. Local fallback controllers are expected to be operated autonomously without telecommunications.…”

“…In the final stage, the AVC system is able to be operated in the closed loop. In addition, the reliability can be enhanced with, so called fallback scheme [52], to automatically control the assigned shunts to maintain the voltage in case the telecommunication between control center and the stations are malfunctioning. …”

“…The fallback scheme is designed to be slower but more aggressive than the relay functions to control the passive shunts for maintaining the voltage [52]. It can be specified to two operational modes.…”

“…The ITC of triggering shunt switches for correcting the voltage violation can be expressed in (7.1) to (7.3) [52].…”

Automatic voltage control (AVC) system under uncertainty from wind power

“…Consequently, an automatic voltage control (AVC) system is required to minimize the operational cost, i.e. consisting of the power loss, the switching cost of shunts, the cost of tap changes of transformers, while maintaining the system voltage profile within an acceptable band [3]- [5]. Typically, in an AVC system, setpoints for reactive power components, obtained from an optimal reactive power flow (ORPF) algorithm, are dispatched periodically, e.g.…”