A new family eugenics based evolution (FEBE) theory is presented to estimate the faulty section in power systems. To apply the FEBE method to solving the fault diagnosis problem

an orthogonal design technique is then introduced into the course of offspring’s breeding inside a family

so as to enhance the behavior amelioration of individuals against pre-maturity and thus quicken the convergence of the low converging speed in the last period. The method proposed is versatile and can deal with uncertainties in fault section diagnosis of such complicated cases as failure operations of relays and circuit breakers

or multiple faults at the same time. The feasibility and efficiency of the FEBE approach developed for fault-section diagnosis has been verified with the result of a sample power system.