A visual identification method with application of partial circuits is developed for characteristic equation coefficients of transients in linear electric circuits. The method is based on interrelationship between the roots of algebraic polynomial and its coefficients. The method is illustrated with an example of a third-order linear electric circuit.

Causes of premature failure of medium-power two-pole induction motor windings after the windings first repair are revealed. Recommendations for the medium-power two-pole induction motor winding reliability improvement are given.

A brief scientific essay on the history of invention of the main welding technologies for metals and other materials is presented.

Behavior of models of three-phase-to-single-phase rotary reversible thyristor converters of brushless synchronous compensators in a circuit simulation system is analyzed. It is shown that combined control mode of opposite-connected thyristors may result in the exciter armature winding short circuits both at the thyristor feed-forward and lagging current delay angles. It must be taken into consideration when developing brushless compensator excitation systems.

The paper presents some principles and results of numerical field calculation and the corresponding harmonic analysis of magnetic field in the active zone of a large turbogenerator under load conditions. In addition to the traditional coordinate function of the magnetic induction, its time functions are considered at fixed points and at rotating rotor linked points in the gap. The stator magnetic flux linkage functions are also examined. It is revealed that these magnetic induction functions, which are different from sine curves, fail to provide the basis for determining time functions of magnetic flux linkage and the stator winding EMF that are close to sine waves.

A technique and results of experimental studies of geomagnetic field (GMF) induction in 195 different rooms in educational institutions, residential buildings, shopping malls and subway are presented. It is shown that in all the buildings there is weakening of the natural GMF. However, the GMF weakening is slight in the most areas and not dangerous to public health. Exceptions are areas of high-rise frame-cast-in-place residential blocks, offices and premises of shopping centers with steel frames and platforms of underground stations. Here, the GMF can be weakened to a dangerous level (less than 25 µT), which requires measures for its normalization.

A field mathematical model of the end zone of a powerful generator type TVV-1000-2U3 in the three-dimensional setting is developed. The modeling of the nominal mode of operation of the turbogenerator is done. The distribution of the electromagnetic field, eddy currents, and the Ampere force appearing in such elements of the end zone of turbogenerator as the pressure plate, push pins and electrically conductive screen.

The paper presents a temperature field calculation technique for a polyfunctional electromechanical transducer with a hollow perforated rotor based on a finite element model of interrelated electromagnetic and thermal processes.

Matlab-models of two converter systems of an 8 MW AC drive are developed, one based on a self-contained current inverter with cut-off diodes, the other based on a multilevel cascade voltage inverter. By applying virtual simulation, qualitative characteristics of these systems are compared.

An experimental study technique for a prototyping system of active screening of power-frequency magnetic field distortions near power station generator buses via controllable magnetic field sources is presented. Results of experimental research on a prototyping active screening system with different control algorithms are given.

In the article, a calculation technique for contact pressure in the axes of mechanical systems based on Comsol Multiphysics package is considered.

A mathematical model of the temperature field of a frequency-controlled asynchronous motor rotor is made out on the basis of differential equations of heat conduction. The model developed is approved in the course of experimental research on the motors examined.

Theoretical aspects of an experimental determination method for residual and inductive magnetic moments of a technical object are considered. As input data, the technical object magnetic induction signatures obtained under its linear movement near a pair of three-component sensors are used. A magnetic signature integration technique based on spatial harmonic analysis of the magnetic field represented by twenty-four multipole coefficients is introduced.