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  • Author: E. Kamolins x
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Substantial improvement of the undercar inductor generator used for supplying power to passenger cars is achievable through increasing its specific power, reliability, reparability, and decreasing the cost of its manufacturing. It is proposed to integrate electrically the armature and excitation windings of the generator thus considerably simplifying its design while reducing its mass and consumption of non-ferrous metals. To gain these advantages a test prototypal generator was made and bench-tested. The results of tests show that a 1.5-fold mass reduction is achievable along with good technical-economic indices of the generator.

Abstract

The control systems for the objects of industry, power generation, transport, etc. are extremely complicated; functional efficiency of these systems determines to a great extent the safe and non-polluting operation as well as convenience of service and repair of such objects. The authors consider the possibility to improve the efficiency of systems for damping oscillations in transport using a combination of electrical (generators of rotational and linear types) and hydraulic means. Better efficiency of functioning is achieved through automatic control over the operational conditions of such a system in order to make it adaptive to variations in the road profile and ambient temperature; besides, it is possible to produce additional electric energy.

Abstract

The authors consider several tens of rotor tooth and slot profiles for the inductor electric machine in order to gain the maximum EMF of the armature winding at the minimum of highest harmonics, owing to which the specific power and efficiency of the machine can be raised.

The research considers usage of analytical methodology and finite element method (FEM), where the latter includes magnetic saturation and actual magnetic field line distribution.

The main data of both calculations are summarised in the results of the study. From the obtained results, it can be concluded that, in most cases, the analytical method is not applicable to the qualitative determination of the highest harmonic content of the EMF, since the plane of the magnetic field lines does not close in parallel and their distribution is directly related to the configuration of the teeth zone.

The possibility of using the inductor generators for direct connection to the grid is demonstrated in the study.

Passenger cars of the railway transport are being constantly improved, thus becoming ever more comfortable for public conveyance. These cars are fitted with air conditioners, installations for heating and forced ventilation, heaters, refrigerators; lighting, radio and TV sets; communication equipment, etc. All the listed fittings need continuous and secure electricity supply from a primary independent source. The paper considers the possibilities of meeting requirements for particular power supply systems - first of all for undercar generators. At operation of such a high-power generator under rugged conditions it should be highly reliable, possessing a reasonable mass and high efficiency. The existing designs of these generators still do not meet the listed requirements in full measure. To improve the efficiency of the undercar generator it is proposed to integrate its excitation winding into the armature one, thus reducing the copper consumption, losses and mass, while - which is the most important - considerably raising reliability of the generator and its availability factor.

Abstract

Application of wind generators opens wide possibilities for raising the efficiency of low- and medium-power wind generators (WGs). The mass of generators in the proposed version is smaller, their reliability higher, while maintenance costs are lower. At the same time, the use of high-energy permanent magnets in generators of enhanced power comes up against some obstacles, which can be overcome through proper orientation of magnetization at creation of a magnetic field in the airgap of electrical machine. In this regard, it might be preferable to use magnets with indirect action on the airgap instead of those with direct action. A convincing example of the former variant is a generator with tangentially oriented magnetization of permanent magnets. In the work, an attempt is done to prove the advantages of such installation in modern low- and medium-power WGs

Abstract

The method considered in the present paper concerns the operational efficiency of the inductor electric machine, which can be improved by placing on the stator and rotor teeth the combs combined from differently shaped teeth and slots. The use on the inductor electric machine stator and rotor teeth of combs as a combination of differently shaped hills (teeth) and valleys (slots) allows raising the specific power of the machine. This effect is determined by the chosen type of a comb element as well as by technological possibilities of the manufacturer. The proposed method could be used moderately in the inductor machines with longitudinally-transversal combing.

Abstract

The authors present a methodology for the calculation and optimisation of regulation laws that apply to electronically commutated synchronous motors with predefined characteristics. It is shown that the synchronous electronically commutated motors can provide predefined characteristics with the maintenance of high energy performance by simultaneously regulating supply voltage, excitation current and load angle.

Abstract

The paper discusses issues related to the optimisation of magnetic couplings used in bioreactors (manufactured by JSC “Biotehniskais Centrs”). The purpose of optimisation was to preserve the maximum breakaway torque of the magnetic coupling while reducing the mass of rare earth elements used in its structure. The paper presents the rationale for the selected optimisation option taking into account the economic aspect. To solve the optimisation problem, the factors affecting the maximum torque of the magnetic coupling, such as the shape and height of the internal and external magnets, the angle of the external and internal magnets, as well as the height of the internal and external yoke, were determined. The design of the existing magnetic coupling was optimised and its prototype was made based on the results of optimisation. The results obtained by means of optimisation were compared with the results obtained experimentally by testing the manufactured prototype.

Abstract

The authors present a small-scale wind turbine emulator based on the AC drive system and discuss the methods for power coefficient calculation. In the work, the experimental set-up consisting of an AC induction motor, a frequency converter, a synchronous permanent magnet generator, a DC-DC boost converter and DC load was simulated and tested using real-life equipment. The experimentally obtained wind turbine power and torque diagrams using the emulator are in a good agreement with the theoretical ones.