Efficient control of AC electric drives using the trigger effect of diode-thyristor circuits

Abstract

Relevance: in recent years, Uzbekistan has been working to introduce modern energy-saving technologies into the energy sector. Due to the widespread automation of production processes and the introduction of automatic control systems in industry, the requirements for reliability, speed and durability of electrical equipment have significantly increased, and at the same time, maintenance of equipment during operation should be minimized. Contactless electrical equipment mainly meets these requirements. The problem of creating reliable and economical start-up and switching devices and apparatuses as elements of electrical equipment for alternating current circuits is of great importance for ensuring uninterrupted operation, accuracy and speed of electric drives and other energy devices. In particular, the use of semiconductor contactless switching devices in difficult climatic conditions, in various industries, in the field of automatic control of electric drives and in power supply systems is considered promising.

Aim: development of a non-contact semiconductor device for starting and trip protection at minimum voltages of AC electric drives.

Methods: experimental and theoretical studies of the proposed device revealed a trigger effect in a diode-thyristor circuit, which was used to start and protect against operation at a minimum voltage of an asynchronous motor.

Results: with the help of these studied circuits, it was found that on their basis it is possible to develop a contactless device for starting AC electric motors and protecting them from operation at minimum voltage. A scheme of a contactless three-phase thyristor starter of an asynchronous electric motor is proposed, which makes it possible to avoid the operation of electric motors with frequent starts and a drop in mains voltage.