Measurement of power effects caused by the deterioration of the neutral conductor in three-phase distribution networks

Abstract

[EN] The expressions of the powers that measure the effects of the energies manifested by the deterioration of the neutral conductor in low-voltage distribution networks are developed in this paper with the name of neutral-displacement powers. The expressions of these powers have been obtained by applying the Principle of Energy Conservation to the entire three-phase system and the use of Buchholz's apparent source and load powers. Contrary to the traditional apparent powers of the neutral conductor, these new powers are not affected by the neutral currents and, therefore, their expressions can be applied to analyze the effects of the neutral conductor even though this conductor has been accidentally broken or disconnected. In the application example, based on the three-phase distribution network of a real industrial estate, it has been verified that the neutral-displacement powers reach a maximum value when the neutral conductor has been broken, while the traditional apparent powers of the neutral conductor are worth zero under those conditions. This result confirms that the neutral-displacement powers are more adequate quantities than the traditional ones to measure the impact that the deterioration and disconnection of the neutral conductor can cause in three-phase distribution networks.