This paper introduces a new equivalent circuit for linear direct current
networks consisting of independent voltage and current sources, and
resistors, which represents all the power dissipated internally in the
resistors. It is demonstrated that the internal losses of any network
have two components. One is variable and dependent on the internal
resistances of the actual circuit and the power transferred to the pair
of accessible terminals. The other is constant and dependent only on the
internal voltage and current sources and the resistances of the actual
network. It is also demonstrated theoretically and validated by
numerical simulation that the traditional Thevenin and Norton equivalent
circuits are particular cases of the proposed equivalent circuit in this
paper. The proposed equivalent circuit can be used to analyze power and
efficiencies of the actual network.