Voltage stability of the Puget Sound system under abnormally cold weather conditions

The potential for voltage collapse in the Puget Sound area is analyzed. Shunt and series compensation schemes, as well as undervoltage load shedding, are evaluated. Twenty-five-minute time simulations of the Puget Sound area system are presented, showing interaction of load dynamics with load tap changers (LTCs), switched compensation and protective equipment. The behavior of the system in response to severe loading and critical disturbances under a range of conditions and proposed remedial measures was examined. A detailed discussion of the system behavior is presented