Coordinated Agent-Based Control for On-line Voltage Instability Prevention

Service interruptions have a significant impact on society and therefore the main objective of power system planning and operation is to ensure that they do not happen. Because voltage instability is one of the dynamic phenomena that may result in a system-wide blackout, this type of stability problem has been an important research topic for many years. Grid developments, like the increase of Renewable and Distributed Generation (RDG) and the impact of deregulation, in combination with the steadily increasing electricity demand, will have its impact on the vulnerability of the power system to voltage stability problems. On the other hand, developments in power system monitoring and control such as the use of accurate Phasor Measurement Units and the development of Smart Grid control concepts, introduce new possibilities for voltage instability prevention. In this work the impact of having a large share of RDG capacity on voltage stability is investigated and a new Hierarchical Agent-Based Voltage Instability Prevention (HABVIP) system for online voltage instability emergency control is proposed. The control philosophy uses the maximum loadability index to determine the amount of active and reactive power load relief necessary to restore stability. The intelligence for this control is provided by agents located in the substations: the substation agents. The load relief is obtained by: increase of local generation, virtual load shedding via adjusting the load tap changers set point, intelligent load control and increasing the reactive power output of Static Var Compensators. The control of the actuators is provided by agents located in the actuators: the actor agents. Verification of the system is done by off-line simulations and by building a real-time hardware in the loop demonstration model