scholarly journals Analysis of the influence of non-sinusoidal and unbalanced network modes on induction motors

2021 ◽  
Vol 289 ◽  
pp. 01002
Author(s):  
Ngo Van Cuong ◽  
Lidiia I. Kovernikova
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Induction Motors ◽  
Electrical Power ◽  
Electrical Energy ◽  
Operating Conditions ◽  
Premature Aging ◽  
Electrical Network ◽  
Electrical Networks ◽  
Electrical Power Systems

The parameters of electrical network modes do not correspond the requirements GOST 32144-2013 of Russian and the National technical regulation of Vietnam. In real operating conditions in electrical networks in non-sinusoidal and unbalanced modes there are harmonic components of voltages and currents as well as voltages and currents of negative sequence. They cause additional losses of active power, which leads to additional heating and causes premature aging of the insulation, and as the result, the reduction in the service life of induction motors. Currently, we see that the process of formation of intelligent electrical power systems is underway. Systems for continuous monitoring of power quality indices and parameters of electrical systems modes are being developed. These systems can be supplemented with programs for calculating characteristics that issue the warning when the unfavorable influence of the parameters of non-sinusoidal and unbalanced modes is detected on various electrical equipment of both electrical power systems and consumers of electrical energy. The paper provides an overview of the characteristics used to analyze, assess and predict the influence of poor power quality associated with non-sinusoidal and unbalanced of currents and voltages on induction motors. A computer program was developed to calculate these characteristics. The program was used to study the influence of non-sinusoidal and unbalanced modes on the induction motors of the coal sorting plant of the Vietnamese company “Cua Ong-Vinacomin”.

scholarly journals Analysis of Internal Overvoltages in Transformer Windings during Transients in Electrical Networks

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2644 ◽  
Author(s):  
Jakub Furgał ◽  
Maciej Kuniewski ◽  
Piotr Pająk
Keyword(s):  
Power Systems ◽  
Electromagnetic Waves ◽  
Power Transformer ◽  
Electrical Power ◽  
Operating Conditions ◽  
Electromagnetic Transients ◽  
Electrical Network ◽  
Electrical Networks ◽  
Insulation Systems ◽  
The Impact

Due to the increasing requirements for the reliability of electrical power supply and associated apparatus, it is necessary to provide a detailed analysis of the overvoltage risk of power transformer insulation systems and equipment connected to their terminals. Exposure of transformer windings to overvoltages is the result of the propagation condition of electromagnetic waves in electrical networks and transformer windings. An analysis of transformer winding responses to transients in power systems is of particular importance, especially when protection against surges by typical overvoltage protection systems is applied. The analysis of internal overvoltages in transformers during a typical transient related to switching operations and selected failures is of great importance, particularly to assess the overvoltage exposure of insulation systems in operating conditions. The random nature of overvoltage phenomena in electrical networks implies the usage of computer simulations for the analysis of overvoltage exposures of electrical devices in operation. This article presents the analysis of the impact of transient phenomena in a model of a medium-voltage electrical network during switching operations and ground faults on overvoltages in the internal insulation systems of transformer windings. The basis of the analysis is simulations of overvoltages in the windings, made in the Electromagnetic Transients Program/Alternative Transients Program (EMTP/ATP) using a model with lumped parameters of transformer windings. The analysis covers the impact of the cable line length and the ground fault resistance value on internal overvoltage distributions.

scholarly journals Predicting the influence of the non-sinusoidal network mode on power transformers

2019 ◽  
Vol 114 ◽  
pp. 04005
Author(s):  
Ngo Van Cuong ◽  
Lidiia I. Kovernikova
Keyword(s):  
Service Life ◽  
Electric Power ◽  
Power Quality ◽  
Electrical Equipment ◽  
Operating Conditions ◽  
Transformer Oil ◽  
Power Transformers ◽  
Electrical Network ◽  
Electrical Networks ◽  
Current Harmonics

The parameters of electrical network modes often do not meet the requirements of Russian GOST 32144-2013 and the guidelines of Vietnam. In the actual operating conditions while there is the non-sinusoidal mode in electrical networks voltage and current harmonics are present. Harmonics result in overheating and damage of power transformers since they cause additional active power losses. Additional losses lead to the additional heat release, accelerating the process of insulating paper, transformer oil and magnetic structure deterioration consequently shortening the service life of a power transformer. In this regard there arises a need to develop certain scientific methods that would help demonstrate that low power quality, for instance could lead to a decrease in the electrical equipment service life. Currently we see a development of automated systems for continuous monitoring of power quality indices and mode parameters of electrical networks. These systems could be supplemented by characteristics calculating programs that give out a warning upon detection of the adverse influence of voltage and current harmonics on various electrical equipment of both electric power providers and electric power consumers. A software program presented in the article may be used to predict the influence of voltage and current harmonics on power transformers.

scholarly journals Using waves to generate electricity

2010 ◽  
pp. 10-12
Author(s):  
Anne Blavette
Keyword(s):  
Power Systems ◽  
Wave Energy ◽  
Energy Supply ◽  
Fossil Fuel ◽  
Electrical Power ◽  
Modern Society ◽  
Well Being ◽  
Electrical Networks ◽  
Electrical Power Systems ◽  
Sea State

In less than a century, electricity has become the cornerstone of our modern society. Thanks to it, living conditions have changed more dramatically in 50 years than in two centuries. However, whereas electricity has provided well-being to billions of people over these past few decades, its ever-growing consumption is more and more threatening us. Climate change, fossil fuel depletion, and security of energy supply are crucial issues to be addressed for our “energy society” to be sustainable. Renewables are considered as a major part of the solution. This article deals with the issues related to integrating wave energy into electrical power systems. The major problem associated with wave energy is its variability. Variability can be observed at several time scales: from the range of seconds (wave-to-wave), to minutes (sea-state to sea-state), to days or months (seasonal variations). However, if wave energy is to be used for generating electricity, electrical networks ...

scholarly journals Steady state stability in electrical power systems considering operation limits in generators, transformers and transmission lines

2021 ◽  
Vol 18 (2) ◽  
Author(s):  
Fredy Estuardo Tamayo Guzmán ◽  
Carlos Andrés Barrera-Singaña
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power System ◽  
Transmission Lines ◽  
Electrical Power ◽  
Operating Conditions ◽  
Electrical Power Systems ◽  
Capacity Curves ◽  
Remedial Actions ◽  
Steady State Stability

Electrical power systems are exposed to several events that can cause unstable operation scenarios. This is due to improper operation of certain components. If an event occurs, the system must be designed to overcome that contingency, thus remaining in a permanent condition that must be evaluated in order to monitor and prevent a possible collapse of the system. An evaluation of steady state stability is proposed at this work based on the capacity curves of generators, transformers and transmission lines. These remarked curves provide information on the operation point of these elements, thus allowing the application of remedial actions. PowerFactory and Matlab are used to carry out the tool for monitoring the operation points after a contingency. The effectiveness of the developed tool is validated at the IEEE 39-bus power system model, where results shows that the functionalaty for different contingencies based on the operating conditions when the components of the power system are varied, cosnquently, the tool identifies cases that require actions at the operational level.

Power Quality of Electrical Power Systems

2019 ◽  
pp. 265-288 ◽  
Author(s):  
Feras Youssef Mahfoud ◽  
Basarab Dan Guzun ◽  
George Cristian Lazaroiu ◽  
H. H. Alhelou
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Electrical Power ◽  
Poor Quality ◽  
Energy Costs ◽  
Electrical Power Systems ◽  
Work Stoppage ◽  
Complete Work ◽  
Single Figure

Power quality problems can cause processes and equipment to malfunction or shut down. And the consequences can range from excessive energy costs to complete work stoppage. Obviously, power quality is critical. There are many ways in which a power feed can be poor quality, and so no single figure can completely quantify the quality of a power feed. In this chapter, the authors present all definitions, classifications, and problems related to power quality. Finally, they do a comparison between the practical measurements and standards related to power quality.

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