Features of switching parameters of frequency avalanche diodes and modeling of their application in the electric schemes of protection are considered. Efficiency of protection against of the overvaulting are formed at switching in the course of transients, by means of electric schemes with application of avalanche diodes and there are using clearing of the impulses of overvaulting by initiation of the avalanche discharge. Modeling of work of the electronic power devices was spent in the system MATLAB+Simulink with simultaneous there is application of the package SimPowerSystems.