SIMULATION OF REACTIVE POWER COMPENSATION OF SYNCHRONOUS MOTOR

Simulation results of electromagnetic and electromechanical processes of 8.1 kW synchronous motor in transient mode are presented. Simulation was carried out by means of Matlab Simulink for the motor with feedback on power factor to provide compensation of reactive power.

Determination of the magnitude of short-circuit surge current for the construction of relay protection on reed switches and microprocessors

A study of the functioning of reed switches under the influence of a magnetic field created by a current in a conductor in a transient mode with the presence of an aperiodic component has been carried out. A well-known method for determining current using reed switches was implemented. At the same time, it was determined that the originally formulated method did not give the required result within the limits of errors. This is most likely due to the peculiarities of the mechanism of movement of the reed switch contacts. Alternatively, the measurements were taken to take the return currents instead of the pick-up currents and the time between the return times. They are more stable. Simulation is performed, experimental determination of the value of surge current by measuring time is carried out. The main element of the created installation was the power transformer coil with low active and high inductive resistance. As part of the study, the reed switches were placed in a magnetic field with an aperiodic component, as in the transient mode. This study will show the applicability of reed switches for the construction of relay protection devices that will not need current transformers to obtain information about the primary current in the conductor. In the course of the research, it was found that the error in determining the magnitude of current was no more than 10 %. Using microprocessors, it is possible to build relay protection devices with a speed of up to 20 ms. This result makes it possible to build new devices. Since in the well-known developments, it was only said about determining the magnitude of current in a steady state. When building relay protection devices on reed switches, without using current transformers, it will be possible to build backup protections that duplicate not only the devices themselves, but also the primary measuring transformers with other sensitive elements. This will improve the reliability of the power supply.

Investigating the reliability of all-optical switches in transient mode

In this paper the scheme of 8×8 all-optical switch with two duplicating switching elements and the algorithm of its functioning are presented. For calculating the reliability of all-optical switches, the analytical method based on the Markov process theory is presented. This method allows us to calculate reliability indicators of the all-optical switches as downtime coefficient and availability factor in stationary and transient modes and time of transient mode. The results of numerical calculations show that an increase in the number of duplicating elements by one gives decrease in the downtime coefficient by 6 percent, and the time of the transient process is halved in this case.

Transient Behavior of the MAP/M/1/N Queuing System

This paper investigates the characteristics of the MAP/M/1/N queuing system in the transient mode. The matrix method for solving the Kolmogorov equations is proposed. This method makes it possible, in general, to obtain the main characteristics of the considered queuing system in a non-stationary mode: the probability of losses, the time of the transient mode, the throughput, and the number of customers in the system at time t. The developed method is illustrated by numerical calculations of the characteristics of the MAP/M/1/3 system in the transient mode.

STUDY OF THE APERIODIC REGIME DURING THE TRANSIENT PROCESS IN AN OSCILLATING CIRCUIT IN ORDER TO CONVERT THE ENERGY OF AN ELECTRIC CURRENT INTO THE HEAT OF A JOULE

Purpose. Research initiated by revealing the paradox of disturbed energy balance based on the position of the virial theorem and studying examples of the Van de Graaf generator, a capacitor containing a ferroelectric, and a heat pump capable of providing an energy conversion factor greater than 100%, as well as an idealized theoretical known as the Maxwell demon, showed the possibility of increasing the efficiency of converting current energy into Joule heat. Methodology. The results are verified by comparing the relative efficiency of the conversion of current energy into heat in the oscillatory, critical and aperiodic modes of the transient process in a series oscillating circuit. Mathematical modeling in a wide range of parameter changes has shown the advantage of using the aperiodic transient mode of a series oscillating circuit to convert current energy into heat, compared to the power supply of an electric heating system, which is based on the established method. Experimental tests of the experimental sample fully confirm the qualitative results of mathematical modeling. Results. An achievable limit level of conversion efficiency in the active resistance of energy accumulated by inductance and capacitance according to the virial theorem is established. Originality. For the first time, the application of the aperiodic transient mode in a series oscillatory circuit is proposed in order to convert the energy of current to Joule heat. Practical value. As a practical result, a method of converting current energy into pulse energy has been developed, which implements the algorithm of simultaneous energy accumulation by inductance and capacitance, and its simultaneous conversion in a series oscillating circuit, for which a patent has been obtained. Possibilities of application of the developed method for the purpose of induction heating of metals by Foucault currents as replacement of a method of shock excitation of fluctuations are studied. To this end, the conductivity of metals, which causes the flow of Foucault currents, should be considered as the introduction of equivalent active resistance in the oscillating circuit. The introduction of the method will not require changes in the process equipment, except for the power supply scheme, and should eliminate the fundamental disadvantage of the method of shock excitation of powerful oscillations, which is low efficiency.