Abstract
The article presents an approach to the development of mathematical models of non-sinusoidal and dual-frequency power supply for a linear induction MHD machine for metallurgical purposes. The issues of construction and numerical modeling of the modes of a three-phase inductor for a liquid aluminum stirrer are considered. Reduction of losses is ensured by the use of a toothless design of the MHD inductor. The absence of steel teeth reduces saturation of the magnetic circuit and current distortion. It is proposed to use the parametric model of the inductor under the furnace in the ANSYS environment to clarify the modes of the complex. To take into account mutual induction, using controlled sources, a circuit model was built, and a numerical calculation of the modes was carried out. The characteristics of instantaneous currents and voltages are obtained when powered from a three-phase source with close frequencies, with pronounced beats. It is shown that the presence of mutual inductance redistributes currents in the delta windings, which must be taken into account when developing the design of linear induction machines. It is proposed to use sources with non-sinusoidal periodic currents in the modeling system. The analysis is carried out and the main types of modulated voltage characteristics in the power supply system of the induction MHD stirrer are shown.
Highlights
Power supply of linear induction machines (LIM) for MHD stirrers of aluminum melt in mixers and furnaces is traditionally performed at a low frequency using frequency converters [1]
Special symbols mark the curve for the first phase alternation in direct sequence
The simplest solution here is to replace the module of an idealized power supply with EMF sources (eu(t), ev(t), ew(t)), with a dual one, built on the basis of series connection of sinusoidal EMF sources (Fig. 5) or parallel connection current sources (ju(t), jv(t), jw(t))
Summary
Power supply of linear induction machines (LIM) for MHD stirrers of aluminum melt in mixers and furnaces is traditionally performed at a low frequency using frequency converters [1]. Stirring of the melt is performed periodically, in cycles of 10-20 minutes during melting, lasting up to several hours. In this cycle, the IGBT transistor converter goes through the stages of start-up, acceleration, reversal, deceleration and shutdown [2]. It is necessary to apply special protection measures that differ from the standard ones in order to limit overvoltages and extreme currents, especially in emergency power shedding modes [4]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
