Investigations of transients in the novel semiconductor device of forced control of the vacuum contactor monostable electromagnet

Abstract

The analysis of the disadvantages of the existing systems of forced control with buster and holding windings, in which the opening internal control contacts are used, which commute large starting currents, is carried out. The analysis is led to the search for new technical solutions related to improving the reliability of such systems by eliminating the indicated control contacts. A novel semiconductor device of forced control of the vacuum contactor monostable electromagnet is proposed, in which a simple electronic circuit is used instead of an unreliable internal control contact. The experimental investigations of the operating features of the novel semiconductor device of forced control of the КВТн-250/1,14 vacuum contactor monostable electromagnet produced by the Electrodynamics Company are carried out. Two series of experiments are conducted: the first series of experiments was conducted for the semiconductor device of forced control, in which there is no closing internal control contact, and the second series of experiments – for a forced control system in which the closing internal control contacts which commutes the insignificant current in the control circuit is used. The oscillograms of current and voltage in the buster and holding windings are obtained at various voltage values U = 220, 180, 150 V, and when powered from a source of constant voltage, and then from a source of alternating voltage. The conclusions are made and it is recommended to use a closing internal control contact in the forced control system of the vacuum contactor monostable electromagnet, which will operate when the moving part ends moving before the control device triggers, which will not allow a large starting current to flow through the starting windings. The novel semiconductor device of forced control of the monostable electromagnet is used in the products of the Electrodynamics Company and is successfully operating since October 2017 and still at several mining enterprises (mines, processing plants).