harmonics effect to the network practical case
TRANSCRIPT
European International Journal of Science and Technology Vol. 9 No. 11 November 2020
Cite this article: Alkhalifah, A. & Habiballah, I.O. (2020). Harmonics effect to the network – Practical Case. European International Journal of Science and Technology, 9(11), 1-8.
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Harmonics effect to the network – Practical Case
Ayoub Alkhalifah1 and I.O Habiballah
2
1College of Electrical Engineering, KFUPM, Dahran, Saudi Arabia
Email: [email protected] 2College of Electrical Engineering, KFUPM, Dahran, Saudi Arabia
Email: [email protected]
Published: 30 November 2020
Copyright © Alkhalifah et al.
Abstract
This paper shows the effect of harmonics in power quality for the electrical network. Also, it will represent
the problem that can appear in the network because of high harmonics. Moreover, this paper will discuss one
case study and provide the proper solution based on given information from the end user.
Keywords: harmonics, THDV, THDI, AHF.
I. INTRODUCTION
In recent years, power quality become one of the main important topics in power system field because the
poor power quality will lead to lose money from the electricity supplier as well as end user. Power quality is a
major concern for transmission and distribution utilities, industries, and transport and infrastructure sectors.
Poor power quality affects grid reliability, productivity, leads to higher operating costs and penalties for non-
compliance with grid codes.
Poor power quality means any event related to the electrical network that makes end user lose money, there
are three main parameters that cause poor power quality which it will lead to energy losses and high running
costs: harmonics, reactive power, and load imbalance. A poor power factor can be a result of either
significant phase difference between voltage and current at the load terminals, or it can be due to a high
harmonic content. Poor load current phase angle is generally the result of an inductive load such as induction
European International Journal of Science and Technology ISSN: 2304-9693 www.eijst.org.uk
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motors, power transformer, welder, etc. [1]. In this paper the focus will be on harmonics. Harmonics appear
in voltage waveform because of electronic devices that draw current in nonlinear way. Moreover, harmonics
can increase the current in power system which results higher losses (I2R) and increase the heat in neutral
conductor and distribution transformer as well. Nonlinear loads change the nature of sinusoidal wave form of
AC power current and this will lead to AC voltage drop consequently [2-4].
There are two definition for total harmonic distortion (THD), the harmonic existing in the network compared
with fundamental. The other definition, the harmonic content in network compared with waveform’s rms
value [5].
There are a lot of products, systems and services that improve power quality including capacitors and filters,
power electronics-based compensators and software solutions, across the power value chain for low, medium
and high-voltage applications, helping to shape a stronger, smarter and greener grid.
In this paper ABB software called “PQF sizing application“ will be used to provide a solution that will damp
the harmonics in the system network using active harmonics filter (AHF). Using ABB software to get a
solution comply with IEEE 519 standard by damping the harmonics in the system network up to the accepted
value based on IEEE 519 standard [1] as shown in table I and table II.
Table I: VOLTAGE DISTORTION LIMIT BASED ON IEEE 519
Table II: CURRENT DISTORTION LIMIT BASED ON IEEE 519
II. CAUSES OF HARMONIC DISTORTION
Linear load like electrical heater and lighting bulbs will not cause harmonics while nonlinear load like Arc
and induction furnaces, welding machines, LED light, and telecom system will cause harmonics in the
system.
In general, waveform distortion is due to the presence of nonlinear or time variable impedances or because of
bridge rectifiers, whose semiconductor devices carry the current only for a fraction of the complete period,
thus originating discontinuous curves with the consequent introduction of several harmonics.
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III. PROBLEMS CAUSE BY HARMONIC DISTORTION
Harmonic presence in facility can cause a serios problems like:
Unstable operating of generators.
Voltage flicker: which is the rapid change of voltage with high magnitude causing lighting level variations
which are noticeable or annoying to human beings, the effect is called flicker.
Devices overheating.
To illustrate the effect of harmonic in the network, below figures shown how the current wave form will be
distorted because of harmonics.
Fig 1: Fundamental frequency (without harmonics)
Fig 2: Fundamental frequency + fifth harmonic
Fig 3: Fundamental frequency + fifth harmonic + seventh harmonic
Fig 4: Fundamental frequency + fifth harmonic + seventh harmonic + thirteenth harmonic
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Fig 5: Fundamental frequency + fifth harmonic + seventh harmonic + thirteenth harmonic +
twintyfifth harmonic
Previous figures can show that adding more and more harmonics will end up with a step waveform instead of
sinusoidal waveform.
IV. Harmonics Effect On Power Factor
The power factor (PF) as a term may cause some confusion because there are three different type of power
factor: true power factor, displacement power factor, and distortion power factor. The true power factor takes
in the account [2]:
1. Distortion power factor depend on Total Harmonic Distortion Current THDI.
2. Displacement power factor is known as cosϕ, which is cosine the angle between voltage and current.
V. CASE STUDY
Case study will be analyze using ABB software called “PQF sizing application “to provide a solution that
will damp the harmonics in the system network using active harmonics filter (AHF). In this case study the
aim to reduce harmonic distortion contribution of the loads at LV busbar = 5% (THDI loads = 5%):
Fig 6: Customer Installation & Detailed Load Description
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Fig 7: Transformer, cable, and AC drives characteristics
Fig 8: Waveform for current and voltage with and without AHF
Fig 9: Representation THDI and THDV with and without AHF
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Fig 10: Representation THDI and THDV tables
Based on software the best solution to damp the harmonics up to accepted value (less than 5%) by using
active harmonic filter called” PQFS-M10 S10”.
The main technical specification for this product shown in table III.
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TABLE III: THECHNICAL SPECIFICATION FOR AHF (PQFS)
Description Value
Altitude Up to 1000m above sea leve
Minimum temperature -10°C
Maximum temperature +40°C
Degree of protection IP30
Dimensions per enclosure W x D x H: 588 x 310 x 705 mm
CT requirements 3 CTs are required (Class 1.0)
Network voltage ratings 380 V to 415 V between phases
Network frequency 50 Hz or 60 Hz
Current ratings Unit type 7: 100 A
Neutral current ratings 270A
Harmonics that can be filtered
15 harmonics individually selectable in the range
2nd · 50th
harmonic order if the neutral is connected
Degree of filtering Programmable per harmonic in absolute terms
Filtering efficiency Better than 97% of filter rating typically
Response time 40 ms typically (10% - 90% filtering)
VI: CONCLOSION
Finally, case study shows how the harmonic can cause a distortion in both current and voltage waveform.
Also, there are high amount of current losses that cause a poor power quality, high losses, and generate
unnecessary heat that can be avoided by improving the power quality and reduce the harmonic.
In addition, reducing the harmonic will reflect to the power factor and it will improve the power factor in
process with reducing the harmonics.
However, there are no one standard solution can solve all power quality issues. The measurement shall be
taken, and the analysis should be done properly to select the best solution for poor power quality issue.
Acknowledgment
I am grateful for all support from Dr. I.O Habiballah and Electrical Engineering Department at KFUPM for
giving me the resources needed to complete this paper.
References
1) IEEE Power and Energy Society, “IEEE Recommended Practice and Requirements for Harmonics
Control in Electrical Power System” IEEE, 3 Park Avenue, New York, NY 10016-5997, USA. IEEE Std
519TM
-2014.
2) ABB Aplication guid, “Harmonics in HVAC application”, Jumet, Belgium, 2018
3) D. Shmilovitz, “On the Definition od Total Harmonics Distortion and its Effect on Measurement
Interpretion”, IEEE Transaction on power delivary, Vol. 20, No. 1, January 2005.
4) T. Taufik, “Introduction to Harmonics in Power System” ResearchGate, California Polytechnic State
University, San Luis Obispo, August 2018.
European International Journal of Science and Technology ISSN: 2304-9693 www.eijst.org.uk
8
5) A. Bendre, “Harmonics in Modern Electrical Power System”, Transcoil TCI, LLC, Grant Drive,
Germantown, Wi53022.
6) M. Scheidiger, “Power System Harmonics Analysis of High Power Variable Speed Drives”, KTH
Electrical Engineering, XR-EE-E2C 2013:009, Stockholm, Sweden, 2013
7) M. Jawad Ghorbani and H. Mokhtari, “Impact of Harmonics on Power Quality and Losses in Power
Distribution System”, IJECE, Vol. 5, No. 1, pp. 166-174, ISSN: 2088-8708, February 2015.
8) M. Shafiee Rad, M. Kazerooni, M. Jawad, and H. Mokhtari, “Analysis of the Grid Harmonics and Their
Impact on Distribution Transformer”, ResearchGate, DOI: 10.1109/PECI.2012.6184593, February, 2012.
9) W. Mack and Robert J. Gilleskie,”Harmonics and How they relate to Power Factor”, Proc. of the EPRI
Power Quality Issues & Opportunities Conference (PQA’93), San Diego, CA, November 1993.
10) J. Ghorbani, “Nonlinear Loads Effect on Harmonic Distortion and Losses of Distribution Networks”,
DOI: 10.13140/2.1.5047.3288, June, 2011.
11) S.Khalid and B. Dwivedi, “Power Quality Issues, Problems, Standards & Their Effects In Industry With
Corrective Means”, IJAET, ISSN: 2231-1963, I.E.T., Lucknow, India, May, 2011.
12) A. J. Buckley and M. Duncan, “General Application Note, Harmonics Guide”, General Application Note
DDLM014 Rev. A, Drive Dynamics, April, 2009.
13) C. Kocatepe, R. Yumurtaci, O. Arikan, M.Baysal, B. Kekezoglu, A. Bozkurt, and C. Fadil, “Harmonic
Effects of Power System Loads: An Experimental Study”, INTECH, 2013.
14) Prof. Mack Grady, “Understanding Power System Harmonics”, University of Texas, Dept. of Electrical
& Computer Engineering, April, 2012.
15) L&T Electrical and Automation, “Understanding Current & Voltage Harmonics”, L&T Switchgear.
16) Z. Hameed, M. Rafay, A. Yousaf, and M. Usman, “Harmonics in Electrical Power Systems and how to
remove them by using filters in ETAP”, ResearchGate, Superior University, Faculty of Engineering and
Technology, Lahore, Pakistan, February, 2016.
17) R. Arghandeh, A. Onen, J. Jung, D. Cheng, R. P. Broadwater, and V. Centeno, “Phasor-based
assessment for harmonic sources in distribution networks”, ELSEVIER, Electric Power System Research,
116 (2014) 94-105
18) T. M. Blooming, D.J. Carnovale, “Application of IEEE STD 519-1992 Harmonic Limit”, Eaton
Electrical, North Carolina, Pennsylvania, USA
19) D. J. Carnovale, T. J. Dionise, and T. M. Blooming, “Price And Performance Considerations For
Harmonic Solutions”, Power System World Power Quality, Conference, California, USA, 2003.
20) A. Harrison, “The Effect of Harmonics on Power Quality and Engergy Efficiency”, Technological
University Dublin, January, 2010.
21) D. O. Johnson, K. A. Hassan, “Issues of Power Quality in Electrical System”, International Journal of
Energy and Power Engineering. Vol. 5, No. 4, 2016, pp. 148-154, July, 2016
22) R. C. Dugan, M. F. McGranaghan, S. Santoso, and H. W. Beaty, “Electrical Power System Quality”,
Second Edition, McGraw-Hill.