In this paper, a new method is proposed for fault location using minimum number of phasor measurement units (PMUs) in a power network. In this method, all possible fault points over transmission lines are rep- resented as virtual buses, and corresponding bus impedance matrices are calculated. Because capacitive property at the virtual buses is neglected, resulting impedance matrices are linear with respect to fault point distance. Using voltage data provided by PMUs and applying superposition theorem, potential fault points on every single transmission line are extracted, each by solving linear equations, and then, exact fault loca- tion is obtained using two prede fi ned rules. In addition, fault type and fault impedance are determined by some criteria involving symmetrical components. Merits of the proposed method include simpli fi ed equa- tions, thanks to linearity provided by omitting capacitive effect, as well as minimum required PMUs to be installed in the network. Besides, a set of fundamental rules describing PMU placement constraints, according to required voltage data of different points in the network, are introduced. Employing these rules ends up to a fewer number of required PMUs in comparison with other proposed methods. At the end of this paper, the accuracy of the suggested method has been evaluated by applying it on three test systems, namely Institute of Electrical and Electronics Engineers (IEEE) 30-bus, IEEE 39-bus, and IEEE 118-bus. Simulations, performed by MATLAB Simulink (MathWorks, Natick, MA, USA), indicate high accuracy and consistent results of the proposed method.

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