DEVICE THAT ABSORBS ZERO-SEQUENCE HARMONICS IN LOW-VOLTAGE ELECTRICITY DISTRIBUTION NETWORKS.

摘要

The invention relates to a device, autotransformer and system for eliminating zero-sequence harmonics for unbalanced three-phase systems with non-linear loads, which comprises a siliceous steel core equipped with plates for reducing losses caused by parasite currents; terminals in terminal blocks suitable for each value of current and a metal cabinet with forced ventilation and an air louvre suitable for the thermal flow that it is desired to evacuated, the siliceous steel core comprising three C-shaped legs disposed one in front of the other at 120° intervals, forming a three-pointed star; three windings of copper insulated according to the power or current circulating through the windings, with taps for making the phase connections or crossings. According tot he invention, the distribution of flows being is distributed in the three legs of the siliceous steel core in a proportion of 50% in the first leg, 25% in the second leg and 25% in the third leg, for each phase, the polarity of the second and third legs being reversed, causing the flows in the second and third legs to be summed with a sign opposite to that of the flow of the first leg, giving a result of zero. The neutral current is thereby absorbed and the residual current is re-injected into the phases in a balanced manner.