Diagnostics of windings of a three-phase induction motor with a square rotor

The issues of technical operation, diagnostics and repair of electrical equipment are always relevant, especially for merchant ships, because to achieve an economic result from the activities of shipping companies, the uninterrupted operation of ship mechanisms, devices and systems is important. To ensure uninterrupted operation, proper technical operation of shipboard electrical equipment, prevention of typical malfunctions, reliable diagnostics of electrical equipment and timely repairs are necessary. The diagrams of the connection of the stator winding of an asynchronous motor with a short-circuited rotor “Star” are given. A method for diagnosing the technical condition of the stator windings of a three-phase asynchronous motor with a short-circuited rotor, which does not involve disassembling the motor, by alternately measuring the resistances between the phases of the motor, is considered. In this case, a three-phase asynchronous motor with a phase rotor is considered as part of a simple system in which there are no restrictions on starting currents, reverse, changing engine speed, switching windings. To analyze this method, a set of educational and laboratory equipment “Three-phase asynchronous motor with fault simulator” was used, with which it is possible to set typical faults for a three-phase asynchronous motor. Variants of fault combinations are being considered. It is noted that the conclusion on the technical condition of the engine should be made, in particular, according to the values of the ohmic resistance of the engine windings. The necessary measurements were carried out for various types of malfunctions; based on the obtained measurement results, a conclusion was made about the proposed method.