Synthesis of a fractional-order PIλDμ-controller for a closed system of switched reluctance motor control

The paper presents studies of the system "induction generator-induction motor" with parametric asymmetry on a mathematical model to determine the quality of generated electricity in load operating modes. A mathematical model of the "induction generator-induction motor" system has been developed taking into account losses in steel and parametric asymmetry. The analysis of the transient characteristics of an induction generator when a motor load is connected in symmetrical and asymmetrical modes of operation is carried out. The results of changes in the main characteristics of an induction motor at various degrees of parametric asymmetry in the generator are presented. The quality of the generated electricity was analyzed based on the calculations of the unbalance coefficients for each of the operating modes. The assessment of the thermal state in steady-state conditions was carried out using an equivalent thermal equivalent circuit. Thermal transients were investigated when starting an induction motor from an autonomous energy source based on an induction generator. On a thermal mathematical model, the study of the effect of the output voltage asymmetry on the heating of the connected induction motor was carried out. It is shown that the asymmetry of the output voltage of an induction generator reaches 3–10 % and causes overheating of the windings in excess of the permissible values. A regression model has been developed for studying the operating conditions of an induction motor when powered by an induction generator with an asymmetry of the stator windings. The use of the obtained equations will make it possible to determine the most rational combination of factors affecting the heating of the stator windings of induction machines, in which they will not overheat above the maximum permissible temperature values of the corresponding insulation classes

Three-phase asynchronous motor with a short-circuited rotor has been described with the help of a model convenient for the analysis of changes of its power indices in terms of different values of all the indices of supply voltage quality. Mathematical model of electromechanical converter with the power of 11 kW has been verified based upon the results of industrial experiment in the workshop of “Ukrspetsservis” Ltd. While checking the validity of the model, the obtained values of relative mean square error of modeling make it possible to be used for the purpose of computational studies of asynchronous electric motor energy efficiency.

Preparation and preliminary analysis of data on energy consumption by municipal buildings

The topicality of the research aim is caused by the analysis of the processes of energy conversion taking into account the induction motor particular nonlinearities that reveal the physical properties and phenomena in structural materials under the action of electrical and electromagnetic impacts. Taking into consideration the nonlinearities of the induction motor equivalent circuit influences the accuracy of determination of the electric machine operating characteristics. Most conventional methods for parameter identification do not enable assessment of the induction motor nonlinear characteristics and properties.It is proposed to use resistive impedance and inductance dependences on the rotor current to take into account the rotor nonlinear parameters. To form identification equations, the instantaneous power components for the rotor nonlinear resistive impedance and nonlinear inductance have been obtained. The solution of the identification equations resulted in determination of the equivalent circuit electromagnetic parameters taking into account the rotor nonlinear parameters and the amplitudes of the harmonics of the current cosine and sine components of the rotor and magnetization circuit. The results of identification of the induction motor equivalent circuit parameters taking into account the rotor nonlinear parameters have been obtained with sufficient accuracy. This is confirmed by a low error of determination of the electromagnetic parameters. The adequacy of the identified parameters is determined by comparison of the stator current experimental and calculated curves

The paper analyzes negative impact of poor-quality electricity on the performance of electrical installations. Particular attention is paid to the reasons for the deterioration of the quality of electrical energy in the power supply systems of industrial enterprises since it leads to a decrease in the reliability and efficiency of electrical consumers. Different character modes of consumption and generation of reactive power in the lines with 27.5, 10 and 0.4 kV have been determined. A wide variation in the statistical characteristics of power quality indicators and significant distortion curves current form have been determined that will help elaborate more accurate methodology of measures to improve the quality of electricity networks of non-traction consumers.