The independent hidden failure model of CBTMs prevents
considering common mode failures that involve simultaneous
hidden failures of two or more CBTMs as the result of a single
outage event. For example, a loss of the power resource,
which supplies power to twoormoretrip
which supplies power to two or more trip coils, can cause
multiple circuit breakers the enter hidden failure status
simultaneously. When considering common mode hidden
failures of CBTMs in the substation shown in Figure 1,
differential equations that govern the transitions among
substation states, initial conditions, and sum of probabilities
are given below: