Mode restrictions in the power supply system of industrial induction equipment

Abstract

The article investigates the frequency features of the power supply of induction heaters designed for aluminum extrusion. Mode regulation is performed by local connection of capacitor banks with the creation of parallel resonance. The scheme of the power supply system is built on the basis of an adjustable frequency converter. To study the induction complex, a mathematical model was created in the frequency and time domains. The calculation showed the possibility of a resonant mode with a deterioration in the frequency regulation of currents with an unsuccessful choice of design. In the course of modeling using a modified nodal analysis, a set of parameters that create a resonance is considered. The frequency characteristics and vector diagrams of the induction device are obtained, which reveal the unfavorable mode. Based on the results of the study, recommendations are proposed for correcting the algorithms for controlling the inverter of the power supply system and overcoming the limitations.