Applied Mechanics and Materials Vol. 792

Abstract: The models of the synchronous generator for calculating the steady-state and transient regimes including the transients of stator windings of generator without damper windings have been presented. The ability to use different mathematical approximations of the generator models depending on the spatial distance of the disturbance point has been shown. The examples of the generator models without damper windings which is equipped with an automatic stabilizer have been given. To determine the currents and voltages as functions of time the state-space technique and Park – Gorev transformation have been used. Solutions are obtained by means of the program called integrated environment MathCAD Runge-Kutta method.It is possible to use these models in networks containing synchronous generators and also for the design of objects containing generators.

Abstract: Modern development of distributed sources of electricity in Russia is impossible without the development of means to improve its dynamic stability during sudden changes of regime. In this paper a solution of using a pseudo-direct drive is proposed. The relevance of the study is related to the fact that Russia distributed energy sources in isolated power systems have little power. Unfortunately, there are some drawbacks of such power systems in terms of electricity problems associated with the loss of dynamic stability during short circuits.

Abstract: The paper describes finding magnetic system rational geometrical ratios for a linear cylinder electromagnetic motor with the active teeth-slot zone. Rational ratios were found with finite-elements simulation and analytical derivations with respect to motor efficiency. The rational geometrical ratios ranges have been found for the inductor active volume. The investigation results can be widely used in design of electromagnetic motors with various teeth-slot zone configurations.

Abstract: The paper reports on results of studying self-starting capabilities of a commercial machine with fractional slot concentrated windings. The results are obtained by mathematical modeling techniques and experiment.

Abstract: The additional torque caused by the static eccentricity in multipole permanent magnet machines is investigated in the paper. The equation governing the dependence of the additional torque on number of poles and the amount of eccentricity qualitatively is developed. Analytical conclusions are verified by the results of numerical simulation.

Abstract: Permanent magnet synchronous motors for the effective start requires information about an initial position of a rotor. In this regard, most systems use position sensors, which substantially increase a cost of an electrical drive entirely [1-3]. The aim of this article is to develop new method, allowing to determine the absolute angular position of the rotor of the permanent magnet synchronous motors [4,5]. With a certain voltage pulses, in series applied to the motor, stator is magnetized by currents leakage in the windings. This allows, using a special algorithm, to calculate the absolute position of the rotor without using any motor parameters [6]. Simulation results prove the simplicity and efficiency of this method for determining an initial position of the rotor of the permanent magnet synchronous motors. Thus, this method can be widely used in the electrical industry.

Abstract: The paper presents the design peculiarities of the asynchronous motor with an asymmetric magnetic core having ceramic insulation, the motor being designed for the application under severe radiation conditions.

Abstract: A simulation model of a pulse frequency-phase discriminator (PFPD) in the Matlab Simulink application package was developed. The main PFPD modes simulation and the analysis results were carried out. The simulation results are discussed in this paper.

Abstract: The advantages and shortcomings of three-level voltage source inverters to be applied on locomotive traction electric drives are highlighted in relation to two-level ones. To protect wheels from slipping on rails, the control system is designed. The control system with protection from slipping uses system of direct torque control as the subordinated contour to produce control signals on voltage source inverter. The topology and principles of operation of both protections from slipping and direct torque control of traction induction motor with three-level voltage source inverters are described. The simplified structure of mechanical part of traction drive using basic and axle suspension is considered. The adequacy of designed control system is confirmed by means of Matlab, the results of mathematical modeling show a high convergence with the results of physical model of traction drive.

Abstract: The mathematical description of the wear processes of brushes of brush-type motors is described. The actions directed on increase of the lifetime of brushes are offered. The proposed mathematical model of the wear processes of brushes considers the highest number of parameters of a sliding contact, including sparking energy of windings switching and the mechanical condition of a commutator and bearings. The approach for evaluating the optimum pressure on the brush in order to increase its resource is offered. The real and the virtual lifetime tests of the universal motor considering changing of the mechanical state of the commutator and bearings during lifetime were carried-out. The constant force value acting on the brush which provides its lifetime increase by 11% is proposed.