КОМУТАЦІЙНИЙ СТРУМ ПЕРВИННОЇ ОБМОТКИ ТРАНСФОРМАТОРА ПРИ ВАРІАЦІЯХ СТРУМУ ЙОГО ХОЛОСТОГО ХОДУ

Abstract

Transformers are an indispensable component of various types of electrical circuits. Various restrictions are imposed on the transformer switching operation, which are caused by the functional purpose of the systems, their configuration, parameters and characteristics of existing or available switching components or devices and associated transient processes. When the power transformer is switched on asynchronously, current surges in its primary winding, including in modes close to the min-imum load, may exceed its nominal current by several times. Such processes are undesirable from the point of view of energy efficiency, electromagnetic compatibility, transformer reliability and the functioning of protection systems. Proper analysis of electromagnetic processes was performed by numerical calculation methods followed by computer modeling using the MATLAB/Simulink software package. The purpose of the study is to highlight the extreme nature of switching current surges of the primary transformer and their dependence on the relative value of the no-load current of the winding. This current, in turn, depends on the slope of the main functional segment of the magnetization curve of the transformer core corresponding to its stationary mode of operation. The research shows that the increase in the idle speed of the transformer causes a directly proportional decrease in the switching current surges of the primary winding of the transformer. At the same time, the difference between the amplitude values of adjacent semi-periodic current surges decreases. It is noted that an increase in the value of the transformer's no-load current is often aimed at stabilizing the burning of the alternating currentarc in electric welding installations. They are characterized by a repeated short-term mode of switching, and therefore the determination of the mag-nitude of switching current surges is relevant here