This paper describes a computer model for calculating the surge propagation in the winding of electrical machines. The model considers the winding as a combination of a multiconductor transmission line and a network of lumped parameters. The frequency dependence of the winding electrical parameters is calculated and incorporated into the analysis by means of Foster and Cauer circuits. The multiconductor transmission line provides the surge propagation characteristics for the winding model and its parameters are calculated from machine design characteristics. Finally, this hybrid model is validated by a comparison of calculated and measured results inside a high-voltage machine winding.