Upon noticing a voltage decrease at key stations, what should a System Operator's first action be?

The first action a System Operator should take upon noticing a voltage decrease at key stations is to place capacitors in service. Capacitors are used in power systems to provide reactive power support, which assists in maintaining voltage levels within acceptable limits. By placing capacitors in service, the operator can quickly increase the reactive power supply, which in turn helps to stabilize the voltage.

When voltage decreases occur, this typically indicates a need for reactive power; placing capacitors in service is often the most immediate and effective way to address this issue. It allows for a reactive power boost to counteract the demand and maintain the voltage stability in the system.

Other approaches, such as directing generators to produce more reactive power or re-dispatching, may take longer to implement or may not address the immediate voltage issue as directly as placing capacitors does. Reducing interchange may also not effectively mitigate the voltage decrease at key stations. Thus, placing capacitors in service represents the quickest and most efficient response to a voltage drop scenario.