Sources of Transient Overvoltages

There are two main sources of transient overvoltages on utility systems:capacitor switching and lightning. These are also sources of transient overvoltages as well as a myriad of other switching phenomena within end-user facilities. Some power electronic devices generate significant transients when they switch. As described in Chap. 2, transient overvoltages can be generated at high frequency (load switching and lightning), medium frequency (capacitor energizing), or low frequency.