Improving the reliability of electric motors during startup using electroosmotic drying of insulation

Abstract

<jats:p>The article considers the actual problem of electric motors (EM) operation associated with wetting of winding insulation. The condition of wet insulation is getting worse due to aggressive environment of premises of agro-industrial complex, and some workshops in industry. It is noted that together with humidification, the effect of insulation “steaming” occurs after EM is put into operation. In this case, the insulation resistance R sharply decreases and its breakdown may occur, after which a major overhaul of EM is required. A new method for EM drying based on the electrokinetic phenomenon of electroosmosis has been developed. Under the influence of electric field forces, moisture is extruded from insulation capillaries onto the surface of EM winding and stator iron. R increases, and EM becomes ready to turn on. Under further operation, EM is heated and moisture evaporates into the environment. It is shown how electroosmotic drying (EOD) and the developed device (DEOD) help to get rid of the effect of insulation “steaming” and thereby ensure trouble-free EM operation.</jats:p>

Destruction of electrical insulating structures of electric motors during various drying techniques

“…One of the main reasons for failure of electric motors is moisturization of winding insulation. For this reason, up to 20-30% of electric motors fail annually [1][2][3][4][5][6][7]. Our studies show that for air humidity of 100% and temperature of 35 °C, the insulation resistance R drops to a critical value of 0.5 MΩ within 9-10 days.…”