Specific parameters comparison of synchronous reluctance electric drives
The article presents the principles of comparison of different types of synchronous contactless electric drives. The mathematical description of the system is given for comparison. It is shown that classical unregulated synchronous electric drives are inferior to induction electric drives by 30–40%. It is caused by both a decrease in excitation and a decrease in the limiting load angle according to the conditions of static stability. The phase current of electric drives with FRRM has a rectangular shape which allows one to significantly improve the weight and dimensions. In this case, the electric drive with FRRM due to the compensation of the armature transverse response allows improving the system characteristics, so that the induction motor is 10–15% less than the FRRM.
A method of calculating the thermal state of an electric machine using three-dimensional numerical simulation programs
In this article, a procedure for numerical simulation of the temperature of electrical machine components with a combined cooling system is considered: by means of flowing cooling, part of the external surface of a motor housing is cooled with water and the internal area of the electrical machine is cooled with air. A comparison of results of simulation by the provided calculation procedure with the experimental data is given.
A mathematical model of the synchronous reluctance machine with independent control along the excitation line
A mathematical model of a synchronous reluctance machine with independent regulation along the excitation line is presented. The electromechanical converter unit is presented as a system with distributed parameters and designed by the finite element method, while the semiconductor converter is approximated with a continuous dynamic element. The case of regulated induction electric drives is used to show by statistical methods that the results produced by the calculation according to the proposed mathematical model at loads from 0 to MN are close to the figures calculated using common calculation procedures. It is shown that, because of the very roughly considered saturation of the magnetic system, it is incorrect to use common mathematical models in the design of induction electric drives in the critical and supercritical torque regions. For this reason, the developed mathematical model can also be used in the design of common electric drives in the torque overload area.