New selective control strategy of power system properties

This paper presents a new technique to coordinate distributed load switching in order to restore the voltage during disturbed conditions. The technique of today is mainly based on load shedding, but the restoration of the load is manually controlled. With increased and intelligent signal analysis in the distribution and transmission systems it is possible to switch load automatically, both on and off, without jeopardizing the system constraints. The technique is based on strategic distributed load switching indicators, LSI-units, coordinated by master LSI-units in the transmission system. This paper focuses on voltage restoration control during distributed condition, when normal voltage control has failed. The LSI-units are used to guide the amount of the load to be manipulated in order to change the voltage to a certain value at a nod. Particular when the system is under restoration after a severe fault, these indicators can and support the operators.