Effect of Switchgear Failures in Calculations of Structural Reliability of Power Supply Circuits at Industrial Facilities

We have analyzed the states of switchgear from the standpoint of power supply system reliability. We have found out that the circuit breaker is one of the most complex switchgear elements, which is why switch failures should be taken into account in industrial power supply circuits. The existing failure states classification is refined by adding new element failure types for which we introduce four new classes. The classes are thoroughly described with formulas for calculating the contribution of the cut-sets of additional classes to the system failure probability, as well as the average system failure flow. The invented methodology thus helps to evaluate and analyze the structural reliability of industrial power supply circuits with the account of switchgear failures, to compare various circuitry options and to choose the most optimal one.