Upgrading of induction motors with energy efficiency enhancement at the electrical repair shops and sites of the running industrial companies

Abstract

It is demonstrated that the main disadvantage of induction motors is a relatively low power factor. In order to enhance energy efficiency of the electric drives, it is proposed to use an innovative technology of their upgrading in the course of overhauls. A distinctive feature of the proposed overhaul is the recalculation of the stator winding considering the real state of the stator steel and uses the phenomenon of current ferro-resonance in the machine's electromagnetic system. This makes it possible to create an induction motor with the desired power factor, even equal to one. Upgrading allows increasing the efficiency factor and reducing the active power losses by 3-7% in the electric drive system and in the power supply system. Additional expenses for upgrading costs amount to 23-30% of the conventional overhaul costs. However, these additional expenses can be justified within 0.25-0.8 years due to energy savings. The results of this R&D project can be recommended for review to the power departments of the running industrial companies, electrical repair shops and energy saving centers. © Published under licence by IOP Publishing Ltd.