A general method is presented for generating the directed k-tree polynomial of the directed graph associated to an active electrical network by means of its multi-level vertex tearing and its corresponding directed k-hypertree polynomial. Using it the scale of electrical networks which can be topologically analysed by a computer will be increased

and the result expressions are terse. Furthermore

for the special case k=l

e = 2

the recursive formulas are presented for generating the directed hypertree polynomials of a hypergraph having two hyperedges. Using it the directed tree polynomial of a directed graph G can be found conveniently and efficiently. Its expansion gives all directed trees of the graph G.