scholarly journals IDENTIFICATION AND ASSESSMENT OF THE INFLUENCE OF UNBALANCE VOLTAGE SOURCES IN THREE-PHASE THREE-WIRE ELECTRIC NETWORKS

2019 ◽  
Vol 2019 (6) ◽  
pp. 65-73
Author(s):  
Yu.L. Sayenko ◽  
◽  
D.N. Kalyuzhniy ◽  
V.A. Bolgov ◽  
◽  
...  
Keyword(s):  
Electric Networks ◽  
Three Phase ◽  
Unbalance Voltage

scholarly journals Sistem Proteksi Motor Induksi 3 Fasa Terhadap Bermacam Gangguan Menggunakan Mikrokontroller

2020 ◽  
Vol 10 (1) ◽  
pp. 9-17
Author(s):  
Darmawansyah Darmawansyah ◽  
M Khairul Amri Rosa ◽  
Ika Novia Anggraini
Keyword(s):  
Distribution System ◽  
Induction Motors ◽  
Electrical Equipment ◽  
Electric Power System ◽  
Protection System ◽  
Voltage Unbalance ◽  
Current Voltage ◽  
Three Phase ◽  
Unbalanced Voltage ◽  
Unbalance Voltage

ABSTRACTIn the current era of globalization, various human jobs depend on electrical equipment such as three-phase induction motors. Three-phase induction motors are very important to use according to their roles and functions. The occurrence of voltage variations in the electric power system is due to the magnitude of the voltages between the three phases which are not the same so that there are differences in the angle of the R, S and T phases, which causes an uneven load overload in the electrical distribution system. Among the disturbances that can occur are overvoltage, under voltage, unbalance voltage between phases, overload, and overheating. Based on these problems, a three-phase induction motor protection system was designed, the system uses current, voltage, temperature sensors, which functions to measure the value when a disturbance occurs, a magnetic contactor as a breaker and a liaison when the disturbance is given in accordance with the set point value given to the microcontroller. The results of the research for unbalanced voltage of V1 112 V, V2 114 V, V3 108 V, overvoltage of V1 228 V, V2 207 V, V3 264 V, over current of A1 104 A, A2 107 A, A3 0.77 A , the overload on the resistance source is 333 ?, 250 ?, 200 ?, 167 ?, and the overheating is 40.75 ºC at 6.5 minutes with tripping conditions in each test. The final results of this study indicate that the protection system which is designed is better used for three-phase induction motors.Keywords: unbalaced, disturbances, protection systems, sensors, magnetic contactor, microcontroller.

scholarly journals Experimental study of quality and electricity losses in low voltage rural electric networks

2021 ◽  
Vol 23 (3) ◽  
pp. 209-222
Author(s):  
O. S. Rakhimov ◽  
D. N. Mirzoev ◽  
E. I. Grachieva
Keyword(s):  
Low Voltage ◽  
Experimental Studies ◽  
Digital Information ◽  
Electric Networks ◽  
Daily Consumption ◽  
Measuring Device ◽  
Three Phase ◽  
The Republic ◽  
Information Database

THE PURPOSE. Due to the increase in the number of farms in the Devashtichsky district of the Sughd region of Tajikistan, over the past 3-4 years, a disproportionate distribution of electricity in the 0.4 kV network has been observed. Unbalance currents of phase loads in relation to asymmetric phase voltages at the terminals of consumers of a three-phase network cause additional losses of electricity, which can reach 21% of the standard losses. In the decree of the President of the Republic of Tajikistan dated May 10, 2009 No. 29 “On energy saving and reduction of electricity losses” it is indicated that there is a need to study the quality of electricity in rural 0.4 kV networks and its compliance with GOST 32144. 2013, as well as an assessment of losses electricity in its distribution structure is an important task in the field of rural electricity. METHODS. A single-line diagram of a 0.4 kV network with initial parameters, which were refined during the survey of the network, and the current loads of outgoing lines were investigated. Experimental studies of the quality of electricity and assessment of the level of losses in the low- voltage network were carried out using a complex measuring device «Energotester» PKE - A - C4. RESULTS. The studies allowed obtaining data on the daily consumption of electricity in individual outgoing lines, information on the characteristics of consumers, digital information (database) on indicators of the quality of electricity in low-voltage networks. CONCLUSIONS. It has been established that the main factors influencing the losses of electricity in low-voltage networks are: incommensurability of the power of transformers of transformers and consumers, uneven loading of individual phases, a significant effect of individual converters on the quality of energy. Measures are forecasted to reduce losses and improve the quality of electricity in low-voltage rural networks of 0.4 kV.

scholarly journals On the choosing the installation location the balancing devices in low-voltage distribution electric networks

2021 ◽  
Vol 2094 (5) ◽  
pp. 052012
Author(s):  
I V Naumov ◽  
S V Podyachikh
Keyword(s):  
Power Quality ◽  
Low Voltage ◽  
Experimental Studies ◽  
Distribution Networks ◽  
Electrical Networks ◽  
Process Change ◽  
Electric Networks ◽  
Concentrated Load ◽  
Operating Modes ◽  
Three Phase

Abstract The experimental studies result on the power quality and additional power losses analysis caused by the asymmetric modes occurrence in three-phase four-wire 0.38 kV electrical networks are considered. The operating modes 38 kV networks several types simulation – with power take-off nodes distributed along the power line, and an electric network with a concentrated load is carried out. The programs have been developed that allow to assess the change in indicators characterizing asymmetric modes, as well as programs that allow us to visualize this process change. The most installing special symmetrical devices appropriate places in electric networks with a distributed load (rural electric distribution networks) and concentrated power take-off nodes electric networks (urban electric networks) have been identified to minimize losses and improve the power quality. A numerical studied indicators analysis was performed.

Identification of Power Grid Lines with Increased Power Losses Using Mobile Electric Meters and Timers

2020 ◽  
pp. 31-36
Author(s):  
Aleksandr V. Vinogradov ◽  
Aleksey V. Bukreyev ◽  
Alina V. Vinogradova ◽  
Vadim E. Bol’shev
Keyword(s):  
Single Phase ◽  
Power Grid ◽  
Electricity Consumption ◽  
Electrical Energy ◽  
Research Purpose ◽  
Power Losses ◽  
Electric Networks ◽  
Operating Modes ◽  
Three Phase ◽  
Quality Of Electrical Energy

Identifying sections of 0.4 kilovolt power grid lines with increased power losses is an urgent task, the solution of which will free up some of the funds spent by power grid companies to compensate for power losses and direct them to the reconstruction and modernization of electric networks. It is necessary to monitor electricity consumption on sections of power grid lines and on the connections of consumers, and compare data on consumption. Existing devices that analyze the quality of electrical energy and can control current and power in the network, such as power quality analyzers, do not have the full necessary qualities, since they are intended for other purposes, and they are also very expensive. (Research purpose) The research purpose is in developing technical means for identifying sections of 0.4 kilovolt power grid lines with increased power losses, which also allow performing a survey of operating modes of power grid lines. (Materials and methods) The article presents a review of literary sources and an analysis of statistical data. (Results and discussion) The article presents developed technical tools for inspection of power grid lines of 0.4 kilovolts and identification of areas with increased losses of electrical energy, portable single-phase and three-phase electric meter and timer. The single-phase mobile electric meter and timer can be used for the survey of single-phase connections of consumers, three-phase one can be used for the survey of any sections of power lines. Authors also developed a version of the portable electric meter and timer with up to six independent sensors. (Conclusions) It is most rational to use a version of the mobile meter and timer equipped with Wi-Fi data transmission technology to detect power losses on sections of 0.4 kilovolts power grid lines, since in this case simultaneous monitoring of several sections is provided with the possibility of obtaining information from sensors in real time. The data allow to calculate technological and commercial losses on power line sections and draw conclusions about whether they are overstated.

Consideration of Nonsinusoidal/Unbalanced Operating Conditions of a Municipal Electric Network for Calculating the Current Level through the Neutral Conductor

2021 ◽  
Vol 1 (1) ◽  
pp. 35-43
Author(s):  
Mukhammadzhon М. KAMOLOV ◽  
◽  
Sagid A. АBDULKERIMOV ◽  
Khurshed B. NAZIROV ◽  
Shokhin D. DZHURAEV ◽  
...  
Keyword(s):  
Harmonic Component ◽  
Operating Conditions ◽  
Electric Networks ◽  
Electric Network ◽  
Three Phase ◽  
Zero Sequence ◽  
Flow Through ◽  
Higher Harmonic ◽  
Harmonic Components ◽  
Electric Loads

During the operation of 0.4 kV electric networks, asymmetry of currents and voltages is unavoidable. As is known, unbalanced operation of 0.4 kV networks is stemming from nonuniform distribution of loads between the phases. This results in that a fundamental frequency zero-sequence current will flow through the neutral conductor in a four-wire three-phase electric network. On the other hand, during balanced operation of a four-wire electric network containing loads with a nonlinear volt-ampere characteristic, higher harmonic currents multiple to three are summed in the neutral conductor. Therefore, it is of relevance to analyze unbalanced operating conditions of a four-wire electric network containing loads with a nonlinear volt-ampere characteristic. The article presents the characteristics of a municipal load for analyzing unbalanced/nonsinusoidal conditions of its operation. For carrying out full-valued assessment of unbalanced operating conditions of a four-wire electric network, a simulation model of a 0.4 kV network section containing a nonsinusoidal load is developed. It is shown that during unbalanced operation of an electric network containing electric loads with a nonlinear volt-ampere characteristic it is recommended to take into account zero-sequence current higher harmonic components that are not multiple to three. An algorithm for calculating the neutral conductor current harmonic component for determining the cable temperature rating is developed.

scholarly journals Development of Three-phase Unbalance Voltage Fluctuation Compensating System using Self-commutated Static Var Compensator.

1996 ◽  
Vol 116 (8) ◽  
pp. 826-834 ◽  
Author(s):  
Masatoshi Takeda ◽  
Shotaro Murakami ◽  
Akihiro Iizuka ◽  
Yoshifumi Mochinaga
Keyword(s):  
Static Var Compensator ◽  
Voltage Fluctuation ◽  
Three Phase ◽  
Unbalance Voltage

A Passivity-Based Power Control Strategy of VSR PWM Rectifier under Unbalance Voltage

2012 ◽  
Vol 622-623 ◽  
pp. 1503-1509
Author(s):  
Yu Ling Ma ◽  
Jiu He Wang ◽  
Hao Xiang
Keyword(s):  
Control Strategy ◽  
Positive Sequence ◽  
Pwm Rectifier ◽  
Performance Simulation ◽  
Grid Voltage ◽  
Actual Application ◽  
Component Theory ◽  
Three Phase ◽  
Unbalance Voltage ◽  
Control Research

In actual application the three-phase gird voltage is unbalanced, but the control strategy of PWM rectifier is always based on balance grid voltage. So the control research of rectifier under unbalance voltage is necessary .In view of the mathematical of rectifier is nonlinear, we will adopt a kind of nonlinear control strategy called Passivity-Based Control (PBC).First based on Symmetric component theory we extract positive sequence of unbalance grid voltage, and then establish the standard Euler-Lagrange (EL) model of rectifier under positive sequence, next we design the system controller based on the PBC theory. Based on passivity of rectifier, we can redistribute the system energy, and improve system performance. Simulation results show that PBC method under unbalance grid voltage is practicable.

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