scholarly journals The impact of the larger number of non-linear consumers on the quality of electricity

2019 ◽  
Vol 32 (3) ◽  
pp. 369-385
Author(s):  
Enver Agic ◽  
Damir Sljivac ◽  
Bakir Agic
Keyword(s):  
Total Duration ◽  
Harmonic Component ◽  
Simulation Models ◽  
Voltage Level ◽  
Harmonic Content ◽  
Three Phase ◽  
Harmonic Components ◽  
Parallel Filter ◽  
The Impact

Theoretically this paper will explain the formation of higher harmonic components in the electricity network, their causes, consequences on consumers and the ways of their elimination. Transformer role in the Dyg connection will be explained on the concrete example. For a specific example the waveform of primary (R) phase at 10 kV voltage level, the current of the secondary (r) phase and the neutral conductor at the 0.4 kV voltage level will be determined as shown in the concrete example in the work. Harmonic content will be determined up to 15 harmonics and the effective value of all these currents (phases R and r). THD for current of primary (R) phase and secondary (r) fase will be calculated. In this paper, the dimensional three-phase filter is set to eliminate the maximum harmonic component of current of the primary (R) phase on the 10 kV side of the transformer. The waveform, the corresponding harmonic content for the current and THD of primary (R) phase will be determined. Additional measures have been proposed to reduce the THD. Another parallel filter has been realized to eliminate the second by size harmonic components of primary (R) phase current. It will also compare THD for primary (R) phase as in the previous cases. For the total duration of the simulation, the used time is Tstop = 0.1 sec. All of the above simulations will be realized in the MATLAB/PSB program package and simulation models will be displayed.

Regulator Circuit Transformer Voltage-Second Product Analysis

2014 ◽  
Vol 529 ◽  
pp. 501-505
Author(s):  
Chi Zhang ◽  
Ming Zhi He
Keyword(s):  
Power Supply ◽  
Power Electronic ◽  
Product Analysis ◽  
Power Regulator ◽  
Current Voltage ◽  
Three Phase ◽  
The Impact ◽  
Power Electronic Technology ◽  
Primary Current

With the continuous development of power electronic technology, the advantages of thyristor power regulator circuit gradually get more and more applications. It improves the quality of power supply, makes the equipment efficiency and power factor higher and so saves a lot of electricity. Through the calculation of the primary current when thyristor turns off in three-phase power regulator circuit with transformer load, the impact of the thyristors turn-off order on the transformer primary current voltage-second product is analysised, and through simulation the exactness is verified.

Linkage Mechanisms With Cam-Integrated Joints for Controlled Harmonic Content of the Output Motion: Theory and Application

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
L. Yuan ◽  
J. Rastegar ◽  
J. Zhang
Keyword(s):  
Closed Loop ◽  
Vibrational Excitation ◽  
High Harmonic ◽  
Harmonic Component ◽  
Linkage Mechanism ◽  
Mechanism Synthesis ◽  
Cam Mechanism ◽  
Harmonic Content ◽  
Harmonic Components ◽  
Four Bar Linkage

In a recent study, the authors presented a systematic method for the modification of the output motion of linkage mechanisms with closed-loop chains using cams positioned at one or more joints of the mechanism. In this paper, the method is applied to the design of a linkage mechanism with an integrated cam mechanism to eliminate high harmonic component of the output motion. The mechanism may be synthesized using any existing linkage mechanism synthesis technique. In the present study, a cam mechanism is synthesized to eliminate all high harmonic components of the output link motion of a four-bar linkage mechanism to illustrate the potentials of the present approach. The mechanism is then constructed and successfully tested. With the present method, selected ranges of high harmonic motions generated due to the mechanisms kinematics nonlinearity can be eliminated by integrating appropriately designed cams, thereby significantly reducing the potential vibrational excitation that the mechanism can impart on the overall system, including its own structure. Such systems should therefore be capable of operating at higher speeds and with increased precision.

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 ANALYSIS OF EXISTING METHODS AND MODELS WHEN RATIONALE OF ORGANIZATIONAL-TECHNOLOGICAL SOLUTIONS OF CONSTRUCTION OBJECTS

2017 ◽  
pp. 74-80
Author(s):  
A. V. RADKEVICH ◽  
I. A. ARUTYUNYAN ◽  
N. A. DANKEVICH
Keyword(s):  
Simulation Models ◽  
Technological Environment ◽  
Construction Organizations ◽  
Effective System ◽  
Market Relations ◽  
The Impact ◽  
Cost Of Construction ◽  
Technology Of Production ◽  
Construction Works

Purpose. A purpose to analyses methods and models, which ground the organization and technology decisions of building of objects, in particular, bridges and transporting tunnels, is put in the article. Methodology. A normative document which is used presently has whole row failings, conditioned by imperfection of information, arbitrariness of form of presentation of information, besides practically does not take into account the requirements of automation. In modern conditions of construction on the optimality of organizational and technological solutions to a variety of factors, some of which are the causes of risk, and the second arises as measures to reduce the impact of the risk. These circumstances require the development of an effective system that minimizes their impact on the selection of optimal organizational and technological solutions. To minimize the time and cost of construction for a given quality of construction works based on the selected methods of organization and technology of production of construction works. Findings. The creation of modern simulation models based on engineering principles that will allow to create optimal conditions to address the complex issues of the reliability of organizational and technological solutions in the construction of objects, in particular, bridges and transporting tunnels. Originality. Has been proved in the conditions of market relations the optimality of organizational and technological solutions can only be achieved at the account of risks arising from changes in the organizational and technological environment of project and construction organizations and other participants of investment and construction activities. Practical value. A simulation technique, which creates additional possibility at estimation of risk due to that does possible appearance of casual scenarios, has developed.

scholarly journals Sensorless Control for Non-Sinusoidal Five-Phase Interior PMSM Based on Sliding Mode Observer

2021 ◽  
Vol 23 (6) ◽  
pp. 445-454
Author(s):  
Youssouf Mini ◽  
Ngac Ky Ngac Ky ◽  
Eric Semail
Keyword(s):  
Control Strategy ◽  
Sliding Mode ◽  
Sensorless Control ◽  
Harmonic Component ◽  
Sliding Mode Observer ◽  
Third Harmonic ◽  
The Third ◽  
Three Phase ◽  
Interior Permanent Magnet ◽  
Harmonic Components

This paper proposes a sensorless control strategy based on Sliding Mode Observer (SMO) for a Five-phase Interior Permanent Magnet Synchronous Machine (FIPMSM), with a consideration of the third harmonic component. Compared to conventional three-phase machines, the third harmonic of back electromotive force (back-EMF) contains more information. Thus, in this paper, the first and third harmonic components of the five-phase machine are considered to estimate the rotor position which is necessary for the vector control. Simulation results are shown to verify the feasibility and the robustness of the proposed sensorless control strategy.

Transient Analysis and Modelling of 2nd- and 4th-Order LCLC Filter under Non-Symmetrical Control

1970 ◽  
Vol 111 (5) ◽  
pp. 89-94 ◽  
Author(s):  
B. Dobrucky ◽  
M. Benova ◽  
S. Kascak
Keyword(s):  
Transient Analysis ◽  
Harmonic Distortion ◽  
Harmonic Component ◽  
Switching Frequency ◽  
Sinusoidal Voltage ◽  
Higher Harmonic ◽  
Simulation Results ◽  
Harmonic Components ◽  
Lc Filter

The paper shows how it is possible to obtain the harmonic sinusoidal voltage on the load side at non-harmonic periodical supplying from the converters. It can be used either LCLC resonant filter for frequency of fundamental harmonic component, or LC filter tuned for switching frequency. Both filters have to remove higher harmonic components from the supplying voltage to reach the harmonic distortion roughly 5 %. The paper deals mainly with analysis and modelling of 4th order LCLC filter (of the first type) under non-symmetrical supply and with comparing to the other types of filtering. Simulation results as well as experimental verification confirm good quality of output quantities of the filter. Ill. 19, bibl. 10 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.111.5.364

Self-Compassion and Quality of Life in Adults Who Stutter

2020 ◽  
Vol 29 (4) ◽  
pp. 2097-2108
Author(s):  
Robyn L. Croft ◽  
Courtney T. Byrd
Keyword(s):  
Quality Of Life ◽  
Social Connectedness ◽  
The Self ◽  
Future Research ◽  
Self Compassion ◽  
Adults Who Stutter ◽  
And Gender ◽  
Relationship Of ◽  
The Impact

Purpose The purpose of this study was to identify levels of self-compassion in adults who do and do not stutter and to determine whether self-compassion predicts the impact of stuttering on quality of life in adults who stutter. Method Participants included 140 adults who do and do not stutter matched for age and gender. All participants completed the Self-Compassion Scale. Adults who stutter also completed the Overall Assessment of the Speaker's Experience of Stuttering. Data were analyzed for self-compassion differences between and within adults who do and do not stutter and to predict self-compassion on quality of life in adults who stutter. Results Adults who do and do not stutter exhibited no significant differences in total self-compassion, regardless of participant gender. A simple linear regression of the total self-compassion score and total Overall Assessment of the Speaker's Experience of Stuttering score showed a significant, negative linear relationship of self-compassion predicting the impact of stuttering on quality of life. Conclusions Data suggest that higher levels of self-kindness, mindfulness, and social connectedness (i.e., self-compassion) are related to reduced negative reactions to stuttering, an increased participation in daily communication situations, and an improved overall quality of life. Future research should replicate current findings and identify moderators of the self-compassion–quality of life relationship.

Surgery for Lung Cancer and the Consequences for the Swallow

2016 ◽  
Vol 1 (13) ◽  
pp. 162-168
Author(s):  
Pippa Hales ◽  
Corinne Mossey-Gaston
Keyword(s):  
Lung Cancer ◽  
Treatment Options ◽  
Vocal Cord Palsy ◽  
Subsequent Treatment ◽  
Physiological Reserve ◽  
Palliative Phase ◽  
And Function ◽  
The Impact ◽  
Swallow Function

Lung cancer is one of the most commonly diagnosed cancers across Northern America and Europe. Treatment options offered are dependent on the type of cancer, the location of the tumor, the staging, and the overall health of the person. When surgery for lung cancer is offered, difficulty swallowing is a potential complication that can have several influencing factors. Surgical interaction with the recurrent laryngeal nerve (RLN) can lead to unilateral vocal cord palsy, altering swallow function and safety. Understanding whether the RLN has been preserved, damaged, or sacrificed is integral to understanding the effect on the swallow and the subsequent treatment options available. There is also the risk of post-surgical reduction of physiological reserve, which can reduce the strength and function of the swallow in addition to any surgery specific complications. As lung cancer has a limited prognosis, the clinician must also factor in the palliative phase, as this can further increase the burden of an already compromised swallow. By understanding the surgery and the implications this may have for the swallow, there is the potential to reduce the impact of post-surgical complications and so improve quality of life (QOL) for people with lung cancer.

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