CHARACTERISTICS OF CONTROL SYSTEMS IN ELECTROMECHANICAL DEVICES

Abstract

Electromechanical devices, control systems convert alternating current of one frequency into alternating current of another frequency, and are also used to control the speed and torque of alternating current motors by changing the frequency and supply voltage. Modern electromechanical devices are used in various industries to ensure continuous process control. The main elements of the control system of electromechanical devices are the power unit and the control device. In most cases, electromechanical systems occupy a central place in technical systems. Their main defining function is the conversion of electrical energy into controlled mechanical energy, i.e. they provide the ability to control the parameters (speed, acceleration, angular or linear displacement, power, torque, etc.) of the mechanical movement of control objects. Usually this function is carried out automatically. The use of various machines, mechanisms and installations in industry, science, everyday life facilitates human activities, increases productivity and quality, improves safety and comfort level. At present, the development and production of various electromechanical installations and elements that perform the same function, but differ in the principle of operation, design, control method and other features, are underway. On the basis of electromechanical systems for working with sensors, converters that convert their parameters into frequency in information-measuring systems have found wide application. The advantages of such converters include: resistance to interference, relatively simple application and circuit structure, manufacturability. The development of informa¬tion-measuring systems is characterized by the widespread use of measuring transducers that convert various physical quantities into electrical signals. As part of the information-measuring system, sen¬sors are marked as the first link and its metrological characteristics are determined. The deve¬lopment of modern transistors and thyristor converters is associated with the analysis of volumetric cal¬cu¬lations and research, new control algorithms and new schemes. Currently, such work is usually based on the mathematical modeling of equipment. In many cases, individual nodes of systems are modeled, as far as possible, equipment models are also built. Such models make it possible to analyze elec¬tro¬mag¬netic, electromechanical and thermal processes of numerous interconnected connections and as¬sumptions of elements. Most of the nodes of control systems, according to certain laws, perform the functions of converting and generating electrical signals of the information level. In order to increase the efficiency and reduce the weight and size indicators of the control system, they are aimed at reducing the power of the signals converted and produced on their part. The scheme for generating control pulses primarily depends on the type of control device and its static and dynamic features. Pulse shapers are one of the most widely used components of various electro-mechanical equipment, which are necessary for connecting installations, generating a logic level voltage from active sensors and detecting pulses. Changing the voltage value by the consumer through a pulse converter is called pulse regulation. By means of a non-contact key of the pulse converter, a source of direct or alternating voltage is perio¬dically connected to the load. As a result, voltage pulses are formed at the converter output. Voltage regulation at the load can be carried out by changing the output pulse parameters: duration tu or period T. The most widely used among the regulation methods are: transverse impulse (tu=var, T=const); frequency pulse (tu=const, T=var) and time pulse (tu=var, T=var) . In this case, the relative conduc¬tion time of the control valve is regulated, which leads to a smooth change in the average or effective voltage value. According to a number of features, one can note the classification of pulse converters: in relation to the input and output voltage (step-down, step-up, arbitrary voltage change); by type of key element (in thyristors, field-effect transistors, bipolar transistors). A choke, a capacitor and a battery can serve as an integrating element. Depending on the mode of operation: PWM controllers, relay controllers or on/off controllers. Pulse converters are also divided into reversible and non-rever¬sible. Irreversible converters convert smoothly changing input voltage into pulses of constant ampli¬tude and polarity, but of different duration. Reversing converters convert the input voltage into an alternating voltage (for various half-cycles of duration) or a constant amplitude into a pulsed voltage (for various durations and polarities). In a pulse voltage regulator, the regulating element operates in the key mode. This mode of operation helps to reduce energy losses, improve the weight and overall dimensions. Pulse DC voltage converters have found wide application as a stabilizer, regulator, power source for excitation windings of DC motors, electrical machines and mechanisms. Equipped with modern microprocessor technology, electromechanical converters contribute to the implementation of a wide variety of object control algorithms. Their application allows increasing the level of system automation, implementing energy saving technologies, applying new techno-logies, increasing equipment reliability and service life. Keywords: electromechanical device, electromechanical device, control system, pulse, relay, sensor, power section, power sources, frequency, power supply, output voltage.