ABSTRACT
Transient is a subcycle disturbance in the AC waveform that is discernible as a sharp discontinuity of the waveform. Subcycle transients are some of the most difficult anomalies to detect and treat. Their occurrence can be random, and they can vary in degree depending on the operating environment at the time of occurrence. Steady-state systems are the opposite of transient systems. The circuit model of a transient electrical system will appear considerably different from the steady-state model. Transients are disturbances that occur for a very short duration, and the electrical circuit is quickly restored to original operation provided no damage has occurred due to the transient. The chapter focuses on some of the more common causes of transients: atmospheric phenomena, switching loads on or off, interruption of fault currents, switching of power lines, and switching of capacitor banks. During fault conditions, large currents are generated in an electrical system.
