Performance index and classifier approaches to real-time, discrete-event control

This paper has two parts. Section 1 reviews aspects of transient stability analysis and control with emphasis on how to exploit computation capability for improved off-line, online, and real-time decision making. It also surveys advanced transient stability controls, As an example of a complex instability that is challenging to control, it describes the December 14, 1994 breakup of the western North America interconnection. Section 2 proposes a form of real-time, wide-area, discontinuous transient stability control using decision trees computed on-line as operating conditions change. Input to decision trees are predictor indices measured during a short window following a severe disturbance. Measurements and computations for these variables, mostly taken or computed at generating plants, can include synchronized voltage angles, relative rotor-angle estimates, generator relative speed estimates, electrical positive sequence power as proxy for accelerating power, accelerating energy, etc. Discontinuous control can include generator tripping, fast HVDC power changes, series or shunt capacitor insertion, and dynamic braking. The study system is a relatively small (176-bus) equivalent of the western North American synchronous interconnection.