This paper presents a new method of the harmonic currents reference identification. The principle is based on the transformation of the voltage and current of the electrical supply network in the per unit system. For this proposed solution we suppose that the voltage supply is sinusoidal and the load current is polluted. The harmonic current of nonlinear load is then obtained by the difference between both signals; per unit current and voltage where per unit voltage signal represent the fundamental of the load current. This new method is compared with that of named pq theory. Interesting results were obtained with a very satisfactory filtered current THD.