How to cite:
Riza Effendi Wijaya, Adi Sastra P Tarigan, Solly Aryza. (2022). Study
of Current Instability Testing in Andongan In 150 Kva High Voltage
Air Line. Vol 3 (9): Page 1763-1775
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Eduvest Journal of Universal Studies
Volume 2 Number 9, September, 2022
p- ISSN 2775-3735 - e-ISSN 2775-3727
STUDY OF CURRENT INSTABILITY TESTING IN
ANDONGAN IN 150 KVA HIGH VOLTAGE AIR LINE
Riza Effendi Wijaya
1
, Adi Sastra P Tarigan
2
, Solly Aryza
3
Pancabudi Development University, Medan, Indonesia
123
Email: [email protected]
1
2
3
A RTICLE INFO A BSTRACT
Air transmission lines generally use ACSR type conductors. As
the demand for electrical energy increases, the effort to
increase the capacity of the transmission line is carried out by
optimizing the current-carrying capacity of the existing
transmission line, but the problem that arises in this
optimization is the increase in the voltage and slope of the
conductor. This study aims to determine the effect of line
current instability on conductor temperature, conductor
slope, slope angle and conductor voltage, which is then useful
for the construction of transmission line construction
structures in accordance with the mechanical properties of
the conductors used. This study uses the calculation of the
heat balance equation. to calculate the conductor
temperature. The Basic Span Length method is used to
determine the equivalent span length.
KEYWORDS
150 KV Transmission, Air Line, Andongan, ACSR
This work is licensed under a Creative Commons
Attribution-ShareAlike 4.0 International
INTRODUCTION
The rapidly increasing demand for electricity has led to the need for
additional transmission line capacity in line with the expansion of the capacity of
generating centers (Ananda, Hosea, & Chandra, 2006) . The emphasis of the
problem in this study is that increasing the current-carrying ability can cause an
increase in conductor voltage and slope, therefore it is necessary to investigate
mechanical problems as a result of changes in line current. (Widodo, 2018) . In
order to know how the characteristics will be useful in the design of transmission
line construction (Arismunandar & Kuwahara, 1973) . Problems with mechanical
performance include how the influence of line current on temperature, conductor
voltage, and conductor slope (Arismunandar & Kuwahara, 1973) .
Riza Effendi Wijaya, Adi Sastra P Tarigan, Solly Aryza
Study of Current Instability Testing in Andongan In 150 Kva High Voltage Air
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Air transmission lines generally use ACSR (Aluminum Conductor Steel
Reinforced) type conductors which have an allowable working temperature limit
of 90°C. (Dario et al., 2016) (Hidayat, Saiful Jamaan, & Daby Embang, n.d.).
Considering the increasing demand for electricity, efforts to increase the capacity
of the existing transmission line are carried out by optimizing the current-carrying
capacity of the transmission line. When a conductor wire is stretched between two
points, the wire will follow a curved line from the two points which because of its
own weight will bend downwards. (Lovrenčić et al., 2015) . When the weight that
causes the conductor voltage is too large, it will cause the conductor wire to break
or it can also cause the support tower to be damaged and fall. The conductor
voltage that arises is also influenced by the loads on the conductor wire such as
wind, snow, rain water and so on (Margunadi, 1986) (Amairi et al., 2010).
Changes in slope (due to conductor voltage, wire length and temperature) that are
too large, can also pose a danger to all objects that are under it. (McCombe, 1949)
Air line is a transmission line that transmits electric power through wires
that are hung on towers or transmission poles by means of insulators. The design
of the transmission line will depend on several things such as the amount of power
that must be transmitted, the distance and type of field that must be traversed, the
available costs, other considerations, such as urban problems and the possibility of
increasing the load in the future.
In Indonesia, the government has standardized the high voltage series,
namely: Nominal Voltage (kV): 20 – 70 – 150 – 275 – 400 – 500, The main
components of the transmission line are transmission poles or towers, conducting
wires or conductors as energy conductors, and insulator. Transmission tower or
pole is a transmission line supporting structure, which can be steel towers, steel
poles, reinforced concrete poles and wooden poles. Steel, concrete or wood piles
are generally used in lines with relatively low working voltage (below 70 kV)
while steel towers are used for high or extra high voltage transmission lines.
Broadly speaking, according to the shape or construction, transmission towers can
be divided into 3 types, namely: Steel construction towers, Manesman towers,
Wooden towers.
According to their function, transmission towers are divided into the
following types:
1. Tension tower
The transmission tower with this function, in addition to being a weight-
bearer, also resists the tensile force of the High Voltage Air Line (SUTT)
wires.
2. Support pole (suspension tower)
This type of tower serves to support or support and must be strong against
the gravity of the electrical equipment on the pole.
3. Angle tower
This tower is a tension pole that functions to receive tensile forces due to
changes in the direction of the High Voltage Air Line (SUTT).
4. Pole end (dead-end tower)
This type of tower is a tension pole designed in such a way that it is strong
enough to withstand the tensile force of the wires from one direction only.
This final pole is placed at the end of the High Voltage Air Line (SUTT)
which will enter the switch yard of the Substation.
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5. Transposition Pole
A tower with this type of function is a tension pole that functions as a
place to move the phase arrangement of the High Voltage Air Line
(SUTT) wire.
The main parts of the transmission pile are composed of a pile frame,
travers , foundations and sledges. The pole frame is part of the pole to support
electrical equipment which is generally made of steel, wood or concrete which is
designed in such a way that it is strong against the forces acting due to the pull of
the conductor, wind and the gravity of the electrical material on the pole frame.
Figure 1. Transmission tower construction
If a wire is stretched between two tie points A and B (figure 2), the wire
will not follow a straight line AB , but because of its own weight will bend down
and form a julai (sag). The size of this bend depends on the weight and length of
the wire. The tighter the wire pull, the less July will occur.
The weight of the wire will cause a tensile stress (kg/mm2) in the cross
section of the wire. If the tensile stress of this wire is large, it can cause the wire to
break, or it can damage the wire binding poles . Tensile stress depends on the
weight of the wire and other loads acting on the wire (wind, ice, and wire
temperature).
According to Stokes' law, because of this tensile stress, the wire will
increase in length, depending on the modulus of elasticity of the wire, and the
length of the wire itself. Medium due to temperature changes that occur around
the wire will cause expansion and shrinkage depending on the magnitude of the
temperature change, the coefficient of expansion of the wire and the length of the
wire. The length of the wire depends on the length of the goal (the distance
between the two tie points) and the size of the wedge. On the other hand, the slope
depends on the length of the wire, the tension of the wire, and the temperature of
the wire, and these three quantities affect each other.
Since the working voltage (kV) of the wire is generally high, a wire that is
too large can pose a hazard to other objects in the wire itself. According to the
applicable normalization, the height of the wire above the ground ranges from 7 to
8 meters.
Riza Effendi Wijaya, Adi Sastra P Tarigan, Solly Aryza
Study of Current Instability Testing in Andongan In 150 Kva High Voltage Air
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Table 2
Minimum height of conductor from ground
Voltage
Minimum Height
(feet)
Below 66 kV
20
66 kV – 110 kV
21
110 kV – 165 kV
22
Above 165 kV
23
So it has two limits on the values for stretching a wire, namely:
1. The tensile stress shall not exceed the allowable tensile stress under any
circumstances. The maximum tensile stress will occur at the lowest
temperature and there is a wind load.
2. The distance from the wire to the ground must not be less than the smallest
permissible distance. The largest slope will occur at maximum temperature
and at maximum load.
RESEARCH METHOD
A. ACSR conductor specific data used:
Conductor Type : HAWK
Actual cross-sectional area : 291.6 mm2
Nominal conductor diameter : 21.8 mm
Number of wires/ diameter (in mm) :26/3.5 Al
7/2.75Stl
Wire weight per unit length :997.87 kg/km
Resistance (20°C) : 0.2669 ohm/km
Nominal voltage of conductor : 1800 kg
Elastic Modulus : 7700 kg/mm2
Coefficient of Length Expansion : 18.9 x 10-6 /°C
B. As research material is SUTT 150
kV area of Northern Sumatra in
transmission line
using ACSR HAWK conductors along 184 km.
Tools used:
one unit Intel Core 2 Duo T5750 @ 2.00 GHz 2GB RAM and assisted by Matlab 6.1
software.
path :
The stages of the implementation of this research are as follows:
1. Simulating and calculating the use of the ACSR HWK 240mm2 conductor on the
150 kV high voltage overhead line (SUTT) on the Sigli–Banda Aceh line, by
taking a sample tower that has the same structure as the simulation. The
parameters calculated are temperature, conductor tensile stress, maximum
conductor tensile stress, maximum conductor slope and tilt angle
2. Do the same for ACSR conductors on tower poles that are not the same height.
3. Analysis of the calculation results and comparing the two conductors (analysis of
cable data with the actual installed in PLN).
4. Make conclusions from research results.
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RESULTS AND DISCUSSION
A. The conductor is supported by the same high pole
Figure 3. A piece of wire is supported at points A and B of the same height
( source : TS Hutahuruk, Electrical Power Transmission, page: 150)
To calculate the conductor voltage and the slope in the conductor wire can
be obtained from the Chain Line Equation (Catenary Equation).
(7)
(8)
(9)
(10)
With,
= length of conductor wire or span (meters)
= Specific total weight of wire (kg.m
-1
.mm
-2
)
= Modulus of elasticity of wire (kg/ mm
2
)
= Coefficient of wire length expansion
= Change in temperature (°C)
= nominal tensile stress (kg)
= Initial specific tensile stress (kg.mm
-2
)
= factor of safety (2 – 5)
= cross-sectional area of the conductor (mm
2
)
For example, for the minimum temperature
maximum stress has been
determined
. The maximum stress occurs at the minimum temperature
. If
,
, , ,
,
and
is known, then A and B can be searched, and then
can
be calculated.
From figure 3, for example:
= cross-sectional area of the wire (mm
2
)
= = Specific tension of wire (kg/m/mm
2
)
== Specific weight of wire (kg/m/ mm
2
)
= Horizontal tension of wire (kg/m)
= Weight of wire per unit length (kg/m)
= = length of wire (meters)
= Maximum slope or sag (meters)
= Length of goal or span (meters)
Riza Effendi Wijaya, Adi Sastra P Tarigan, Solly Aryza
Study of Current Instability Testing in Andongan In 150 Kva High Voltage Air
Line
1768
Thus, the horizontal tensile stress at temperature can be calculated as follows:
(11)
The conductor voltage at temperature t
2
is:
(12)
The length of the conducting wire at temperature t
2
is:
=
(13)
The slope at temperature t
2
is:
(14)
The slope angle is:
(15)
with :
L = Width of goal (span) (m)
D = Andongan (sag) (m)
w = Weight of conductor per unit length (kg.m
-1
)
T = Tensile tension of conductor (kg)
T
o
= Horizontal tensile stress (kg)
B. The conductor is supported by a pole that is not the same height
If the supporting poles are not the same height, then what is calculated is
the sloping slope (obligue), which is stated by the formula:
(16)
i.e. distance between the line AB and the tangent to the bend of the wire parallel
to the line AB.
The relationship between inclined slope and slope at the supporting points
is expressed by:
(17)
(18)
The voltage across the conductors at the supporting points A and B is given by:
(19)
(20)
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Figure 4. A piece of wire is firmly supported at points A and B which are not the
same height
(source: TS Hutahuruk, Electrical Power Transmission, page: 152)
C. Analysis of Wind Pressure Against Conductors
Wind pressure affects the specific weight of the wire. The weight of the
wire itself works vertically while the wind pressure is considered to be working
horizontally. The vector sum of these two forces is the total specific weight of the
wire. Generally the wind pressure is expressed as,
(21)
With,
= wind pressure (kg)
= form factor
= Specific wind pressure (kg/mm
2
)
= wind speed (meters/second)
= Surface area of the perpendicular wire
wind direction (m
2
)
Because the wind pressure is uneven, the coefficient of inequality ( = 0.75 in
Indonesia) is used, so equation (21) becomes:
(22)
The value depends on the height of the wire above the ground, as follows:
Table 3. Specific wind pressure values
Wire Height
Above Ground (M)
(Kg/M
2
)
(M/Second)
0 – 25
25 – 60
60 – 100
100 – 150
150 – 200
60
70
90
115
130
31
33.5
38
43
43.5
Source: TS Hutauruk, Electrical Power Transmission, p;155
Riza Effendi Wijaya, Adi Sastra P Tarigan, Solly Aryza
Study of Current Instability Testing in Andongan In 150 Kva High Voltage Air
Line
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The value of the form factor depends on the diameter of the wire, and the prices
are:
Table 4. Form factor values
Wire Diameter
(mm)
Form factor
up to 12
12 – 16
above 16
1.2
1.1
1.0
Source: TS Hutauruk, Electrical Power Transmission, p;156
Value taken = wire length x wire diameter.
(23 )
With,
== Specific wind pressure ( kg.m
-1
.mm
-2
)
= W = Specific self weight of wire (kg.m
-1
.mm
-2
)
= Specific total weight of wire (kg.m
-1
.mm
-2
)
D. Calculation of Basic Span Length
The basic span or often called the goal, is usually determined based on the
type of transmission pole construction and consideration of the bearing strength
and conductor distance. However, a mathematical calculation can be used to
determine the length of this goal. The application of this method is sometimes
necessary given the existence of short and varied sections for the goals in a
section.
(22)
With,
L = Equivalent goal length (meters)
a, b, c and d = length of span in a row (mtr)
Then the magnitude of the slope for the equivalent span can be calculated:
(23)
The research was carried out by calculating the temperature, conductor tensile
stress, maximum conductor tensile stress, maximum conductor slope and tilt angle due to
changes in current flowing in the conductor wire using Matlab.6.1 software for ACSR
type HAWK 240mm2 conductors ( Thrash, 1999) (Hidayat et al., n.d.). Calculation of the
ACSR type HAWK 240mm2 conductor with a diameter that is close to the same as the
actual ACSR conductor installed at PLN is carried out with the aim of being a
reference/comparison in the analysis (Migiantoro, 2002) . The method used in this
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research is to use the equation of conductor temperature analysis, to get the relationship
between current-carrying ability and conductor temperature. Meanwhile, to calculate the
mechanical performance of the conductor includes the maximum conductor, maximum
conductor slope and tilt angle using the Catenary Equation method and the Basic Span
Length method (Prasetyono, 2007) (Kwon, 2011).
E. Conductor Temperature Analysis
Figure 6
Graph of the relationship between the increase in line current and the temperature
of the conductor
The heat generated in the conductor is affected by temperature and heat by
electrical losses as a result of the current flowing in the conductor. The calculation in this
study is to use the Hawk type ACSR conductor with specific data in accordance with
those used in the field. It can be seen from the graph that the increase in line current will
be followed by an increase in temperature. If it is considered that the maximum allowable
temperature in this conductor is 90°C, then the maximum allowable current to flow is
698.4 amperes.
F. Analysis of the Effect of Channel Current on the Same Height Transmission
Tower Slope
An increase in line current will result in a change in the slope of the conductor.
When the line current increases, it causes an increase in skew which is then followed by
an increase in the slope angle of the conductor. This can be seen in Figure 7 and Figure 8
below which show a graph of the calculation results of the slope and angle of the
conductor slope. Taking into account the maximum allowable temperature limit for the
ACSR conductor of 90°C, the maximum slope achieved is 13.1510 meters.
0 100 200 300 400 500 600 700 800
20
30
40
50
60
70
80
90
100
110
arus saluran (ampere)
temperatur konduktor (derajat celcius)
Riza Effendi Wijaya, Adi Sastra P Tarigan, Solly Aryza
Study of Current Instability Testing in Andongan In 150 Kva High Voltage Air
Line
1772
Figure 7
Graph of the relationship between the increase in line current and the slope
of the conductor
Figure 8
Graph of the Relationship of the Increase in Line Current to the Slope Angle of the
Conductor
Changes in line current also result in a decrease in the conductor voltage
(Syahputra & Tharo, 2021) . This is because an increase in current causes an increase in
the temperature of the conductor, this temperature increase causes an expansion of the
conductor which then increases the slope of the conductor. This increase in slope of the
conductor causes the conductor voltage between the transmission towers to decrease.
Figure 9
Graph of the relationship between the increase in line current and conductor voltage
Taking into account the maximum allowable temperature limit for the ACSR
conductor, the magnitude of the conductor voltage drop that occurs when the maximum
line current is 698.4 amperes is 906.9936 kilograms.
G. Analysis of the Effect of Channel Current on Unequal Height Transmission
Tower Slopes
The goal distance or span also affects the slope value. The farther the goal
distance, the higher the wedge produced and the greater the stress (DARIO et al., 2016) .
The angle formed on the paddle is even greater if the goal distance between the two
towers is further away (SLAMET, nd) .
Given that the length of the goal (span) of each tower is not the same , then the
span is equivalent (basic span). In the case of calculating this equivalent span, data on the
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length of the inter-tower gates will be taken, namely data on transmission towers
numbered 260 to 273, with the following data:
Table 5. Data span tower 260 to tower 273
Transmission Tower
Goal Length
(m)
260 – 261
385.57
261 – 262
363.98
262 – 263
304.45
263 – 264
294.58
264 – 265
330.00
265 – 266
340.00
266 – 267
340.00
267 – 268
339.99
268 – 269
339.99
269 – 270
326.42
270 – 271
347.91
271 – 272
301.65
272 – 273
306.99
With the data from the existing goal length, it will get the basic span L length of
335.2613 meters using equation (22) above. Then the size of the andongan is (using
equation 23) obtained a value of 15.6955 m.
CONCLUSION
Based on this research, it can be concluded that; The increase in line current
results in an increase in conductor temperature which is then followed by an
increase in the slope value and tilt angle and a decrease in conductor voltage;
Taking into account the maximum permissible temperature limit for the HAWK
240 mm2 type ACSR conductor of 90°C, the following conclusions are obtained:
The maximum conductor line current is 698.4 amperes.
The maximum conductor voltage is 906.9936 kg.
maximum conductor slope is 13,1510 meters.
The maximum tilt angle is 4.9053°.
Changes in the current of the ACSR HAWK type 240 mm2 conductor from 0
amperes to 750 amperes resulted in an increase in conductor temperature of
232.97%; The size of the ACSR HAWK 240 mm2 conductor that is achieved at a
temperature of 90°C is 13.1510 meters. This result is different from the
calculation carried out by PLN, which is 11.16 meters. The difference in the
results of this calculation is caused by differences in the technical data of the
conductors used because PLN uses the ACSR HAWK 291.6 mm2 conductor.
With the increase in the ACSR HAWK 240 mm2 conductor slope from 13.0678
meters to 13.1626 meters, it can be seen that the stretching of the conductors has
become longer even though it is only 0.801%; An increase in line current also
results in a decrease in the conductor voltage. Based on the maximum temperature
of 90°C, the conductor voltage that occurs is 906.9936 kilograms. The results
obtained are also different from the results of calculations carried out by PLN,
Riza Effendi Wijaya, Adi Sastra P Tarigan, Solly Aryza
Study of Current Instability Testing in Andongan In 150 Kva High Voltage Air
Line
1774
which is 1365 kilograms. This difference in results is caused by several things,
including:
The calculation carried out by PLN is in a still water state or in a state without
the influence of wind.
The calculations carried out in this paper are on the ACSR HAWK 240 mm2
conductor, while the calculations carried out by PLN are on the 291.6 mm2
ACSR Hawk conductor.
REFERENCES
Amairi, M., Aoun, M., Najar, S., Abdelkrim, M. N., Fei, Chunguo, Qi, Guoyuan,
Jimoh, Adisa, Rashidinejad, Masoud, Khorasani, Hamid, & Rashidinejad,
Amir. (2010). Modelling And Simulations.
Ananda, Stephanus Antonius, Hosea, Emmy, & Chandra, Vicky. (2006).
Pengaruh Perubahan Arus Saluran Terhadap Tegangan Tarik Dan Andongan
Pada Sutet 500 Kv Di Zona Krian. Jurnal Teknik Elektro, 6(1).
Arismunandar, Artono, & Kuwahara, S. (1973). Teknik Tenaga Listrik, Jilid Ii:
Saluran Transmisi: Buku Pegangan.
Dario, Paolo, Erkmen, Aydan, Siciliano, Bruno, Orin, David E., Volz, Richard D.,
Luh, Peter B., Volz, Richard A., Taylor, Russell H., Bekey, George A., & De
Luca, Alessandro. (2016). The Institute Of Electrical And Electronics
Engineers, Inc.
Hidayat, Dayat, Saiful Jamaan, Saiful, & Daby Embang, Dany. (N.D.). Kajian
Kelayakan Penyambuangan (Power Of Connection) Pembangkit Listrik
Tenaga Mini Hydro (Pltm) 9, 8 Mw Palangai Hulu Kabupaten Pesisir
Selatan.
Kwon, Ogeuk. (2011). A Study Of Evaluation Methods Centered On Reliability
For Renewal Of Aging Hydropower Plants. Arizona State University.
Lovrenčić, Viktor, Gabrovšek, Marko, Kovač, Matej, Gubeljak, Nenad, Šojat,
Zdravko, & Klobas, Zaviša. (2015). The Contribution Of Conductor
Temperature And Sag Monitoring To Increased Ampacities Of Overhead
Lines (Ohls). Periodica Polytechnica Electrical Engineering And Computer
Science, 59(3), 70–77.
Margunadi, A. R. (1986). Pengantar Umum Elektroteknik. Penerbit Pt. Dian
Rakyat, Jakarta.
Mccombe, John. (1949). Overhead Line Practice. Macdonald.
Migiantoro, Bb. (2002). Kajian Kinerja Mekanis Konduktor Acsr Dan Tacsr
Terhadap Perubahan Arus Saluran. Universitas Gadjah Mada.
Prasetyono, Suprihadi. (2007). Analisis Unjuk Kerja Mekanis Konduktor Accr
Akibat Perubahan Arus Saluran. Jurnal Teknik Elektro, 7(1), 18–25.
Slamet, Sugiyanto. (N.D.). Persepsi Konsumen Mengenai Atribut Jasa
Transportasi Ditinjau Dari Jenis Kelamin, Tingkat Pendapatan Dan Tingkat
Pendidikan.
Syahputra, Erwin Syahputra, & Tharo, Zuraidah. (2021). Analisis Pengaruh
Ketidakstabilan Arus Saluran Terhadap Andongan Pada Sutt 150 Kv. Jurnal
Elektro Dan Telkomunikasi, 4(1), 15–24.
Thrash, F. R. (1999). Acss/Tw-An Improved Conductor For Upgrading Existing
Lines Or New Construction. 1999 Ieee Transmission And Distribution
Conference (Cat. No. 99ch36333), 2, 852–857. Ieee.
Eduvest – Journal of Universal Studies
Volume 2, Number 9 , September, 2022
1775
http://eduvest.greenvest.co.id
Widodo, Apriyadi D. W. I. (2018). Evaluasi Kondisi Perkerasan Dan Prediksi
Sisa Umur Perkerasan Lentur Dengan Metode Pavement Condition Index,
Bina Marga Dan Metode Mekanistik-Empirik Dengan Program Kenpave
(Studi Kasus Ruas Jalan Magelang–Yogyakarta Sta 11±000–Sta 12±000).
Universitas Islam Indonesia.
