Methods of calculation of reliability of protective relay devices

A technique which accounts for the hardware reliability of devices and systems of protective relay of power systems is described. The model developed by the authors to account for reliability takes into account the work of functional and test diagnostic devices, and also checks of the serviceability of devices of protection after their refusal to function. It is remarked that the introduction of automatic and automated diagnostic devices has resulted in the necessity for an estimation of parameters of reliability of protection in "transitional" modes between regular checks of serviceability. Algorithms of simulating modeling of protective relays with the purpose of accounting its parameters of reliability are described.