scholarly journals COMPLEX IMPROVEMENT OF POWER QUALITY AND ENSURE ELECTRICAL SAFETY IN LOCAL POWER SUPPLY SYSTEMS WHEN USING HYBRID FILTER COMPENSATING CONVERTERS

2018 ◽  
Vol 2018 (01) ◽  
pp. 69-77 ◽  
Author(s):  
A.F. Zharkin ◽  
◽  
V.O. Novskyi ◽  
D.O. Malakhatka ◽  
◽  
...  
2021 ◽  
Vol 247 ◽  
pp. 132-140
Author(s):  
Yurii Sychev ◽  
Roman Zimin

The urgency and necessity of choosing and justifying the structures of hybrid filter-compensating devices based on series and parallel active filters to improve the quality of electricity in the power supply systems of enterprises of the mineral resource complex is shown. Mathematical models of hybrid filter compensating devices based on parallel and series active filters have been developed. Based on these mathematical models, computer simulation models of the indicated hybrid structures have been developed. The results of simulation showed the effectiveness of the correction of power quality indicators in terms of reducing the level of higher harmonics of current and voltage, as well as voltage deviations. The degree of influence of filter-compensating devices on the power quality indicators, which determine the continuity and stability of the technological process at the enterprises of the mineral resource complex, have been revealed. It has been established that a hybrid filter-compensating device based on a parallel active filter can reduce the level of higher harmonics of current and voltage by more than 90 and 70 %, respectively, and based on a series active filter, it can reduce the level of higher harmonics of voltage by more than 80 %. Based on the simulation results, the possibility of compensating for the reactive power of a hybrid structure based on parallel active and passive filters has been revealed. The possibility of integrating hybrid filter-compensating devices into more complex multifunctional electrical systems for the automated improvement of the quality of electricity is substantiated, as well as the expediency and prospects of their use in combined power supply systems based on the parallel operation of centralized and autonomous sources of distributed generation.


2018 ◽  
Vol 77 (6) ◽  
pp. 337-346 ◽  
Author(s):  
A. B. Kosarev ◽  
A. V. Barch ◽  
E. N. Rozenberg

Abstract. High-speed railways are fast-growing and promising type of traffic. In Russia development of high-speed railway service is associated with the solution of a number of problems, including infrastructure. Authors propose to use earth connection of the railway catenary with the help of an artificial earthing switch on currently designed high-speed line Moscow—Kazan for 2×25 kV power supply system. Taking into account requirements for electrical safety conditions for maintenance of the track and earthed catenary supports, paper justifies method for calculating allowable voltages of rail—earth points and supports of catenary. Methods takes into account structural features of ballastless track superstructure used for high-speed lines. It is estimated that the voltages admissible under the electrical safety conditions are random in nature and distributed logarithmically normal. When calculating probability of safe operation, one should take into account random nature of both permissible stresses and those actually occurring on the track. It is estimated that the probability of safe operation in traction networks of sections with ballastless track superstructure does not exceed a similar value in electrified sections with the conventional structure of a ballast prism. Feasibility of using a 2×25 kV earth system using an artificial earth connection is confirmed, recommendations on its use are given. Authors substantiate allowable values of the rail—earth voltage and catenary supports, which practically exclude the occurrence of hazardous situations for personnel maintaining the track in sections with ballastless track superstructure.


Author(s):  
S. Denysiuk ◽  
T. Bazyuk

Peculiarities of estimation of total energy losses in electric networks and estimation of nature of electricity consumption in local power supply systems (LES) are given. The structure of additional electricity losses in LES in the presence of higher harmonics of current and voltage is carried out, the generalized schedule of instantaneous functions of current i(t), voltage u(t), and power p(t) on components. The offered indicators of an estimation of the performance of criterion of a minimum of losses of the electric power in LES allow to estimate levels of distortion of power processes at consideration both exchange processes, and at the analysis of additional losses of the electric power. The accuracy of measuring the integrated characteristics of energy exchange depending on the available levels of distortion of voltage and current signals is considered. It is shown that in order to take into account the influence of higher harmonics on the total power consumption, it is necessary to determine the change of Frize QFpower as an indicator of additional electricity losses in the presence of non-sinusoidal currents and voltages in at different ratios between the value of current and voltage of the first and higher harmonics. The evaluation of the efficiency of power consumption regulation using the Frize QF power at an arbitrary time interval, as well as the corresponding current distribution into active and reactive components are considered. The peculiarities of increasing the efficiency of power consumption regulation in LES at the cyclic change of generator parameters and load are analysed.


2019 ◽  
Vol 217 ◽  
pp. 01012
Author(s):  
Igor V. Naumov ◽  
Alexander N. Tretiakov ◽  
Marina N. Yakupova ◽  
Elvira G. Fedurinova ◽  
Dmitriy N. Karamov

The guidelines for the design of rural and urban power supply systems do not consider the issues of reactive power compensation and reduction in additional losses due to unbalanced and non-sinusoidal conditions. At the same time, today’s rural power consumers have a great number of non-linear loads in their residential premises. Moreover, the unbalanced phase currents and voltages are an established fact. The paper aims to demonstrate the extent to which power quality and losses vary in real rural 0.38 kV networks. To this end, the objectives were posed to study the operation of two facilities: 1- switchgear at the cottage (with an installed capacity of 15 kW); 2- switchgear at the communal entrance hallway for 60 apartments in an apartment building (with an installed capacity of 75 kW).


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