Switching transients on overhead transmission lines and the effect of a cable upon them

The subject of electrical transients is a very important one, embracing as it does a study of the conditions prevailing whenever the steady amount of stored energy la a circuit is changed. Therefore any operation such as switching, lightning disturbances, etc., which produce a change in the circuit conditions, resulting in a decrease or increase in the amount of stored energy will produce a transient. The energy may be present in one or more different form's and the resulting transient is known as a single-energy or dougle-energy transient respectively. The two common types of energy storage when dealing with electrical phenomena are the dielectric and magnetic fields, as exemplified by the simple condenser and choke coil.