Three-dimensional electromagnetic field model of an auger electromechanical converter with an external solid rotor

Abstract

Purpose. Creating a three-dimensional mathematical model of the electromagnetic field of an auger electromechanical converter with the external solid rotor, taking into account the geometry peculiarities and the finite length factor. Methods. Calculation of the electromagnetic field distribution has been performed with the use of the computational solving the differential equations by the finite element method in a three-dimensional statement.Findings. It has been set that in the air gap the values of magnetic induction vary in the range of 0.7 -0.8 T, in the flanks of the stator teeth they reach the value of 2 T. Induction in a hollow ferromagnetic rotor varies mainly in the range of 1.3 -2.0 T, and in a thin layer with a thickness of 1.0 -1.5 mm, facing the stator surface, it reaches the value of 2.3 T. Within one pole pitch, the z-component maximum of the eddy currents density is 18ꞏ10 6 A/m 2 on the inner hollow rotor surface. It has been determined that, with the exception of the 'edge' rotor sections, where the transverse component of eddy currents prevails, as well as the sections of the magnetic flux "input" into the rotor, the eddy currents are mainly axial. A comparison of the results of measuring the electric field intensity on the rotor surface evidences a data difference of not more than 4%. The proposed model enables to optimize the design of the converter, in particular, to reduce the magnetic induction in the stator teeth.Originality. Numerical results have been obtained in the form of spatial patterns of distribution and graphical dependences that take into complete account the axial and tangential components of the electromagnetic field. Practical implications.The considered finite element model can be used when analysing the electromagnetic fields in electromechanical converters with a complex secondary part. This will give a possibility to consider the real threedimensional field character, caused by the design peculiarities and the final axial dimensions.

Estimation of Dense Plasma Temperature Formed under Shock Wave Cumulation

“…be noted that under these conditions plasma is obtained only due to the gas-dynamic heating of gas by means of shock waves and due to the shock-free compression of gas [4][5][6][7]. The gas-dynamic method for high-enthalpy plasma obtained in explosive generators is a distinctive feature compared to the prevailing methods of electrical and laser heating [8][9][10].…”

Internal capacitive compensation of the reactive power of the screw electromechanical converter

“…At the same time, all types of dissipative energy component of electromechanical converters are used in the technological process, in particular, for the processing of raw materials. The external massive rotor, for example, of the screw electromechanical converter (SEMC), combined with the executive body -the screw, is in direct contact with the loading and cooling medium and is able to form multiphysics processes of processing raw materials [9]. To increase the power factor of the SEMC, a means of reactive power compensation is required.…”

“…Therefore, the methods of reducing eddy current losses for machines with a solid rotor considered above are associated with the occurrence of current imbalance and additional complications of power electronics devices. But for SEMCs, taking into account the scope of their functional tasks [9,19], the problem of reducing eddy current losses in the rotor is not critical, with the exception of effective control of the power factor.…”