Applied Mechanics and Materials Vol. 792

Abstract: The approach to managing the lifecycle of electrical equipment based on genetic algorithms is considered in this paper. The distinction of the approach is in the use of genetic simulation methods regarding the effective maintenance of electrotechnical equipment. The interpretations of genetic operations in such approach are given. The function of the life cycle of electrotechnical equipment is introduced.

Abstract: In this article the method which allows us to perform the calculation of the electromagnetic field in an electrical motor jointly with the calculation of current in a coil and with the rotor rotation under the effect of electromagnetic forces and loads is considered. The possibilities of this method application to the electrical motor design are demonstrated with several tasks. The comparison with the experimental data obtained for the asynchronous motor with two squirrel-cage windings of the rotor is given.

Abstract: Based on the example of forced-draught fans of the GOFHWB-100 series hot water boilers (gas and oil fired hot water boilers) power supply reserves of the electric drive with two-speed asynchronous motor have been determined. The structural chart of the developed control system of the electric drive with winding changeover depending on the boiler performance is provided. The paper considers power consumption of electric drive in the variable frequency speed control mode at the motor operation on the high and low speed windings. It presents methods for calculation of energy performance based on computing the equivalent efficiency of the fluid-handling application. The analysis of the efficiency change has proved that the variable frequency control enables electric power savings at the low speed winding by 5 to 6%. The results obtained are recommended to be widely applied at the change-over of the electric drives with two-speed asynchronous motors to the variable frequency control of performance.

Abstract: Now rotational electrical machines are used mainly for the implementation a reciprocating motion of working mechanisms and also as the electric generators powered by internal combustion engines. It is achieved by means of the kinematic transfers complicating a design and reducing the drive efficiency. The use of linear reciprocating electric machines allows to eliminate these defects. It should be noted that the most effective ones are the cylindrical designs of reciprocating electric machines with permanent magnets, whose efficiency reaches 93 – 95%. However, the rarity and lack of a mass production of this machine type and special recommendations for their design causes the need of research, directed on search of optimum constructive decisions. The article describes the types of linear electrical machines and summarizes the results of numerical modeling of dynamic characteristics for the three versions of the reciprocating cylindrical machine with permanent magnets of 10 kW with the oscillation frequency of the translator 20 Hz and the length of operating cycle of 120 mm. The most effective design parameters of linear electric machine were determined on the basis of its specific characteristics and analysis of the EMF graphics shape, appearing on the stator windings in the generator mode.

Abstract: The electrical and magnetic materials development, as well as the electrical machines principles of design, prepared the base for the research and new designs of high-performance disk-type electric machines development for use, for example, as a high-performance valve gearless electric drive part.

Abstract: This article represents research on fault diagnosis of inverter electric drives. It puts more emphasis on power electronics and drives. The paper begins with the diagnostics of systems with conventional inverter drives, because knowledge of the fault diagnosis in conventional inverter can be used for its applications in other topologies of inverter drives. Therefore, the article describes several methods for troubleshooting.

Abstract: The paper is presented the method of simulation of voltage on the stator winding terminals of induction motor with impaired short-circuit winding of rotor in the running-out mode. This method allows to simulate processes in induction motors with precision to satisfy the requirements of protection equipment.

Abstract: The frequency variable drivers of induction motors are typically used to control mechanical load. In the paper a frequency control method is proposed to affect regime of the grid that feeds these motors. The method provides successful self-starting or restarting after significant power disturbance of group induction motors. The proposed strategies are applicable for smart grid, for example, demand response technology works well for industrial loads. It is can be useful not only for normal regimes but in case of emergency, for instance, dynamic demand provides accurate control of the load. Both technologies (demand response or dynamic demand) are well integrated in smart grid concept.

Abstract: The article presents the results of the synthesis of universal mathematical model of the excitation system of synchronous machines that can adequately reproduce a variety of excitation systems with different regulation laws. The information about the practical verification of the mathematical model is given in the paper.

Abstract: The paper presents the basics of the technology for rapid crystallization of aluminum alloys in electromagnetic field. It is shown that the ingots produced with the stated technology have even microstructure and improved physical and mechanical characteristics.