Діагностування електрифікованих робочих машин в експлуатаційних умовах

Abstract

UA: роботі отримано метод діагностування робочих машин з електроприводом. Він полягає у визначенні відносних втрат потужності в електродвигуні й механічній частині робочої машини за допомогою дослідів холостого ходу та короткого замикання. Ці досліди запропоновано проводити без застосування регулятора напруги, пристрою для загальмовування ротору і графічної побудови залежностей. Експериментальна перевірка встановила, що він здатен виявляти несправності, які можуть виникати в процесі експлуатації робочих машин. При цьому його технічна реалізація порівняно з існуючими є більш простою і не потребує специфічного обладнання і проведення значних розрахунків. EN: The work considers the control of the functional state of electrified working machines, which are driven by asynchronous motors. It is shown that they are the most widespread due to the high structural reliability of the drive electric motors. However, in practice, many cases of their failure are observed due to the presence of certain operational influences that are difficult to predict during design. One of the ways to correct this situation is to use periodic diagnostics of these working machines. Analysis of existing diagnostic methods revealed their imperfection, which complicates the application of these methods in production operation. Therefore, the paper substantiates rational diagnostic parameters relative power losses in the asynchronous motor and the mechanical part of the working machine, changes in which are caused by their malfunctions. These parameters allow assessing the functional state of the specified elements of the working machine during its periodic control under operating conditions. It is proposed to determine the specified diagnostic parameters using idling and short-circuit experiments. For the drive electric motor, both experiments are conducted, for the mechanical part of the working machine an idle test. The work proposes an original method for conducting the specified experiments, which allows you to get rid of the voltage regulator and the device for braking the rotor. The method of calculating diagnostic parameters based on the results of the specified experiments makes it possible not to perform graphical constructions of the characteristics of the electric motor. The work consists of block diagrams for detecting faults in the drive electric motor and the mechanical part of the working machine. Using the specified diagnostic parameters, the method of their determination and the block diagram for detecting faults, a method for diagnosing working machines with an electric drive based on asynchronous motors has been developed. Its technical implementation, in comparison with existing methods, is simpler and does not require specific equipment and significant calculations. Experimental verification of this diagnostic method has shown its ability to detect the most common faults in working machines. The disadvantage of the method is that it can be used only for asynchronous motors with six output terminals.