Combining wind and hydropower facilities makes it possible to solve the problems caused by power supply shortages in areas that are remote from the central energy system. Hydropower plants and highly manoeuvrable hydroelectric units successfully compensate for the uneven power outputs from wind power plants, and the limitations associated with them are significantly reduced when they are integrated into the regional energy system. Such an integration contributes to increasing the efficiency of renewable energy sources, which in turn reduces our dependence on fossil resources and decreases their harmful impact on the environment, increasing the stability of the power supply to consumers. The results of optimisation calculations show that a consumer load security of 95% allows the set capacity of RESs to be used in the energy complex up to 700 MW. It is shown here that the joint operation of HPPs and WPPs as part of a power complex and hydraulic energy storage allows for the creation of a stable power supply system that can operate even in conditions of variable wind force or uneven water flow. The conclusions obtained allow us to say that the combination of hydro- and wind power facilities makes it possible to solve the problem of power supply deficits in the regions of Kazakhstan that are remote from the central power station. At the same time, hydroelectric power plants and highly manoeuvrable hydroelectric units successfully compensate for the uneven power output from wind power plants and significantly reduce the limitations associated with them during their integration into the regional energy system.

This paper is devoted to the study of CMOS IC parameter degradation during reliability testing. The paper presents a review of literature data on the issue of the reliability of semiconductor devices and integrated circuits and the types of failures leading to the degradation of IC parameters. It describes the tests carried out on the reliability of controlled parameters of integrated circuit TPS54332, such as quiescent current, quiescent current in standby mode, resistance of the open key, and instability of the set output voltage in the whole range of input voltages and in the whole range of load currents. The calculated values of activation energies and acceleration coefficients for different test temperature regimes are given. As a result of the work done, sample rejection tests have been carried out on the TPS54332 IC under study. Experimental fail-safe tests were carried out, with subsequent analysis of the chip samples by the controlled parameter quiescent current. On the basis of the obtained experimental values, the values of activation energy and acceleration coefficient at different temperature regimes were calculated. The dependencies of activation energy and acceleration coefficient on temperature were plotted, which show that activation energy linearly increases with increasing temperature, while the acceleration coefficient, on the contrary, decreases. It was also found that the value of the calculated activation energy of the chip is 0.1 eV less than the standard value of the activation energy.

The effective development of modern welding technologies and the improvement of equipment and materials inevitably require deep theoretical knowledge about the physical phenomena occurring in the electric arc column and in the near-electrode region. However, there is still no convincing theoretical description of an arc discharge. This article demonstrates, through the generalization of known experimental facts and studies using a high-speed camera, that the conductive channel of an electric arc has a discrete structure, consisting of a set of thin channels through which the main discharge current passes. The cathode spot of an arc discharge is a highly heated and brightly glowing area on the cathode’s surface. Electron emission occurs from this region, which supports the discharge as well as the removal of the cathode material. We propose a new technique to study the reverse side of the cathode spot, revealing a structure consisting of individual cells or fragments of the cathode spot. For the first time, we present the anode spots captured by a high-speed camera. We carry out an analysis of the spots’ structure. We determine the parameters affecting the mobility of cathode and anode spots. We propose a hypothesis based on the obtained experimental facts about the heterogeneous structure of cathode and anode spots in an arc discharge and the existence of current filaments that affect the mobility of spots during arc combustion.

THE PURPOSE. The relevance of research is that the comprehensive substantiation of issues aimed at ensuring the effective functioning of the electrical complex with the presence of an electric motor load in conditions of low-quality supply voltage. The aim of the work is to study the effect of the asymmetry of the supply voltage on the service life of an asynchronous motor with a short-circuited rotor. The main attention is paid to the dynamics of changes in the service life of low-voltage asynchronous electric motors of various series, depending on the level of voltage asymmetry. Asynchronous electric motors of the classic series (4A, AI) and the upgraded (5A, AI’) are identified as the object of research. As is known, the efficient and reliable operation of electric motors is characterized by the service life of the insulation of the windings. A qualitative assessment of the operational reliability of AM is determined by the accuracy of forecasting the real life of their service. That is why, it becomes obvious, the task of an adequate assessment of the operational reliability of low-voltage asynchronous electric motors operating under conditions of low-quality supply voltage directly depends on the complex of studies of such an external influencing factor as the asymmetry of the supply voltage. METHODS. The realization of the research objectives was carried out using the software package "SimPowerSystems" of the interactive programming environment Matlab/Simulink. RESULTS. The research was carried out on asynchronous motors with a short-circuited rotor: classic series (4A132S4, AIR160S8), upgraded series (5A132M6, AIR132S4) with P_H = 7,5 kW, rated speed n = 1500 rpm. Modeling of the physical processes of the studied electric motors was carried out by changing the voltage asymmetry coefficient in the reverse sequence (K_2U) from 0 to 5% in increments of 1%. Based on the obtained simulation results, diagrams of the change in the service life of AM from the magnitude of the influencing factor are constructed. The studies performed using computer modeling based on the "SimPowerSystems" software package of the Matlab/Simulink system made it possible to predict changes in the service life of AM, estimate the limits of permissible values of the voltage asymmetry coefficient in the reverse sequence, compare the studied electric motors by the level of resistance to an external influencing factor. CONCLUSION. A comprehensive solution to issues related to improving the operational reliability of low-voltage asynchronous electric motors is one of the priority areas, mainly aimed at ensuring the effective functioning of the electrical complex with an electric motor load. In the course of the study, a detailed assessment and analysis of the degree of influence of the asymmetry of the supply voltage on the operational reliability of low-voltage asynchronous electric motors was carried out. The results of the study were discussed, recommendations for the use of asynchronous electric motors in the presence of asymmetry of the supply voltage were formulated.

The paper considers the main issues of increasing the operational reliability of low-voltage asynchronous electric motors based on a set of studies performed using simulations in the Simulink Matlab software environment. The study defines the allowable operation of asynchronous electric motors under the influence of operational factors. We have conducted the analysis and discussion of the research results and suggested measures aiming to increase the operational reliability of asynchronous electric motors.