RESEARCH OF STARTING MODES OF ASYNCHRONOUS MOTORS AND DEVELOPMENT OF A SOFT START DEVICE

Study of starting modes of asynchronous electric motors. The growth of their demand in industry and everyday life requires an increase in the intensity of use of new systems of the industry existing in the agricultural sector. Currently, there is an aspiration to make the technological process the most automated, as well as to create the most functional and accessible equipment for an ordinary user to understand. Electric drives consume more than 60% of the produced electricity, increasing their energy efficiency is significantly achieved by switching from an unregulated asynchronous electric drive to a regulated one, which contributes to the improvement of the quality characteristics of technological processes, provides the opportunity to automate production, and increases the level of energy and resource conservation. Recently, systems of automated control of technological processes created on the basis of advanced microprocessor equipment have been actively developed, improved and implemented. Nowadays, the method of controlling the start of engines using a frequency converter is becoming more and more common. Until recently, the method of frequency regulation of the electric drive was considered expensive and was used only for a large range of speed regulation, but with the decrease in price and improvement of frequency converters, this control system becomes an almost ideal technical solution from the point of view of controlling the operation of the pump both in the start/stop period and in normal modes. Modernization of traditional control and start-up systems can become a frequency converter with an open software platform, which allows users to refine the software, optimize it for their tasks, including developing and adding their own software modules both at the power inverter control level and at the software-logic level controller for solving local automation tasks. The wide use of asynchronous motors is explained by their advantages compared to other motors: high reliability, ease of repair, small number of structural elements, the possibility of operation from an alternating current network, ease of maintenance. Various methods are used to solve the problems that appear during the uncontrolled start of an asynchronous motor, which to one degree or another ensure the acceleration of the asynchronous motor with a given value of current, which is significantly lower than with a direct (uncontrolled) start [1]. This makes it possible to prevent the premature failure of the asynchronous motor (AD) and driven mechanisms, to increase the resource of the switching equipment, to ensure the possibility of controlling the electric drive using modern automation tools. In addition, the use of modern controlled start-up allows you to reduce the active power consumption, significantly reduce the reactive power consumption, reduce the noise level, and reduce the vibration of the electric motor. The start of asynchronous short-circuited motors by direct connection to the network is usually accompanied by a large starting current, which exceeds the nominal value by several times.