In the third decade of this century

a set of transformation formulas of electrical networks was proposed by G. Kron basing on the assumption of invariance of power between the primitive and actual networks [LI]. It has been pointed out by some authors that Kron’s assumption is incorrect but his formulas give correct results. The problem of the contradiction between the incorrect assumption and the correct results has not yet been well solved. In this paper

the transformation formulas of electrical networks are derived with intermediate network and its primitive intermediate network without basing on the assumption of power. By means of matrix method

it is proved that the total power of primitive network is equal to the sum of the powers in the actual mesh network and the actual node network.