Forming the equivalent rotor current for post repair test of asynchronous motor

Abstract

Modern economic conditions set special tasks to ensure the reliability and durability of the equipment to be used. It is particularly true for such a group of electrical products as induction motors used at almost every enterprise. At present, the accident rate of induction motors at enterprises is high; meanwhile, only up to 25% of the motor base is reequipped annually. One of the main reasons of such a condition is the low quality of repair and the lack of the devices to examine the repaired induction motors thoroughly taking into account the specific “accidental” technical parameters of a tested machine. Based on the fact that asynchronous motors frequently fail for any reasons (overloads, adverse environmental conditions, low quality of power supply etc.) was determined a need for conducting complex repair and maintenance. As a result, it makes possible to re-exploit the engine for a long time. The major weakness of electric motor during the repair works was identified. Consequently, several solutions are proposed for motor windings electromagnetic energy change that help to load the motor excluding the mechanical influence on the shaft. These circumstances are substantiated by the formulas of the frequency, voltage and torque change. Thus, there is an urgent need to create a new equipment type to test the repaired induction motors under load conditions without increasing the testing time period, whose results will allow to estimate the real condition of a motor, namely, to reveal hot spots, loading capacity, etc.