Power Transformer Noise and Noise Tests
|
E. Doğan, B. Kekezoğlu
|
Abstract— Voltage level must be raised in order to
deliver the produced energy to the consumption zones with less loss and less
cost. Power transformers used to raise or lower voltage are important parts of
the energy transmission system. Power transformers used in switchgear and power
generation plants stay in human's intensive habitat zones as a result of
expanding cities. Accordingly, noise levels produced by power transformers have
begun more and more important and they have established itself as one of the
research field. In this research, the noise cause on transformers has been
investigated, it's causes has been examined and noise measurement techniques
have been introduced. Examples of transformer noise test results are submitted
and precautions to be taken were discussed for the purpose of decreasing of the
noise which will occurred by transformers.
I.
INTRODUCTION
Transformers
which are the important building blocks of the power system should be designed
and operated considering both electrical parameters and environmental effects.
The noise level of the transformers used especially in urban areas must be at a
level that does not threaten human health. Despite that the occurrence of noise
on the transformer is inevitable.
|
Power
transformers, which perform the function of obtaining the desired voltage
level, allow to right power transfer. In this respect, utilization rate of
power transformers which are indispensable of power systems is gradually
increasing.
Transformers
inherently may form noise depending on certain factors. This situation has
reached such dimensions that affect human health particularly in urban areas. Therefore,
it has become a liability which investigates the cause of the noise in the
transformer and determines preventive actions.
In this study,
factors leading to noise in transformers are described with detail. Standards
related to noise levels have been revealed and noise tests which have been
realized on transformers have been examined in the light of standards. Noise
measurements which occurred on three power transformers are also presented and
interpreted. Solution recommendations related to the subject as a result of the
thesis are presented.
Power transformers enable
optimum power transfer by making intended voltage level obtained in energy
systems. In this respect, transformers’ usage rate which is irreplaceable for
energy systems is gradually increasing.
Transformers
intrinsically can make noise depending upon some factors. This case affects
human health especially in urban areas. For this reason, it has become a
responsibility to search noise reasons and take preventive activities.
In this study, noise
factors in power transformers are explained in details. Noise level standards
are determined and noise tests on transformers are scrutinized in consideration of the standards. Besides,
noise measurements of three different power transformers are presented and
construed. As a result of the thesis study, solution offers about the topic are
presented.
The noise can be
occurred based on load and no-load on power transformers. The incidence cause
of core noise which is known as no-load noise is elastic length changes in the
core resulting from the magnetization. Load noise occurs from vibration
generation of magnetic force caused by load currents on windings, tank walls
and magnetic shield. On the other hand, the noise occurs from fan and pump
which are used for power transformers as cooling equipment should be taken into
account.
Case studies made so far about the noises occurred in the
transformers are listed below.
A.Ilo, B.Weiser,
T.Booth, H. Pfützner[1] have been investigated the effects of geometric
parameters on transformers in their works. B.Weiser and H.Pfützner[2] have been
investigated the relationship between magnetostriction and magnetic forces and
acoustic noise occurring in the transformer core. Also the single-step-lap (SSL)
and multistep-lap (MSL) methods have been compared experimentally. Ishida,
Okabe and Sato[3] have been investigated the effects of clamping pressure and
the material used on three-phased transformer which was made from different
materials packaged by SSL and MSL methods. Teeraphon Phophongviwat[4] have been
investigated the effects of magnetostriction and magnetic forces on vibration
and noise which occur in the transformer's core in his work. And he has been
intended to determine appropriate parameters to explain the relationship
between transformer's core vibration and noise. Girgis, Bernesjö and Anger[5]
have been investigated the characteristics of load noise, the impact of the
load noises on the overall noise, the parameters which effect the load noise
and methods that can reduce noise in the work they have done. Ertl and Voss[6]
have investigated the effect of load harmonics on the noise occurred in
transformer in 2014.
The reasons of the noises in transformers were explained in the
chapter 2 of this work. In chapter 3, it was explained how the noise tests
should be done and examples of noise measurements are presented. The study was
terminated in chapter 4.
II.
POWER
TRANSFORMER NOISES
The transformers used in power systems should be designed as not to
harm human health. Therefore, it is necessary to clarify the harmful noise
level for human health.
Noise levels that
humans are unsuitable were described in TS 9315 ISO 1996-1/T1, TS ISO 1996-2/T1
and ISO 1996-1:2003 standards. The noise level classification was given in
Table I.
TABLE I
Classification of Noise Levels [13]
Noise in The
First Degree ( 30-65 dB(A) )
|
Discomfort,
Getting Bored, Anger, Concentration and Sleep Disturbance
|
Noise in The
Second Degree ( 65-90 dB(A) )
|
Physiological
Noise, Change of Heartbeat, Acceleration of The Respiration, Decreased of
Pressure in The Brain
|
Noise in The
Third Degree ( 90-120 dB(A) )
|
Physiological
Noise, Headache
|
Noise in The
Fourth Degree ( 120-140 dB(A) )
|
Hearing Disorders
|
Noise in The
Fifth Degree (
 140 dB(A) ) |
Explosion of The
Eardrum
|
The Power
transformers where used in residential area have to generate noise lower than a
level that affect human health. Transformer noise can be examined under three
headings and these are; “Core Noise”, “Load Noise” and “Fan-Pump Noise”.
A.
Core Noise
“Core Noise” occurs
from voltage. Magnetic forces in core are the cause of magnetostriction and
thus occurs vibration on transformer. Core noise arises from oscillation of
silicon steel sheets. “Core Noise”, generally is seen as the source of dominant
noise. Barely at modern transformers which reduced noise components, were
developed core design. At the modern transformers which are developed core
design, is reduced noise components.
B.
Load Noise
Noise which caused by the current is load noises. The source of the
noise increases proportionally with loading of the transformer. Nowadays harmonic
components increase in the power grid because of the developing power
electronic technologies. As a consequence of that form of the sinusoidal wave
is depraved. Harmonic distortion that occurring higher frequency than the
frequency of the fundamental component, give rise to vibration at transformer
winding. Electro-magnetic forces created by the load current constitute leakage
flux at magnetic shield with winding. And this vibration engenders load noises.
For the development of core design at modern transformers, the source of
dominant noise is seen as load noise. In figure 1, load noise frequency
spectrum of a power transformer is shown.
Fig. 1 - The Frequency Spectrum of the Load Noise of the Power Transformer
[5]
C.
Fan-Pump Noise
The third factor which is effective on the
transformer noise is fan and pump noise. As known magnetic induction that
occurs between the nucleus and the transformer windings in the core, cause to
rise in the heat level. Because of reaching very high level of heat value, the
transformer needs to cooling system. Fan and pumps are used in power
transformers in order to form the cooling apparatus. This pump and fans which
is used to cool the transformer are effective at transformer noise even if just
a bit. According to J. Pan and others fan noise is characteristically
broad-band in nature. Therefore it influences little at noise problem in around
transformers [7].
In figure 2 it is shown that
core noise (noise occurring in the unloaded condition), noise occurring under
load and the noise made by fan's sound according to a 333 kVA transformer's
load conditions.
Fig. 2 - Sound Level of a Modern
Low Core-Noised Transformer under the Load Conditions [5]
III.
Transformer Noıse Tests
Before commissioning of power transformers the
essential noise tests have to be done. First tests have to be done are listed
below and sample test results are presented.
A.
Measurements of Noise
Consisting of sound pressure and sound
intensity, there are two different measurement methods to evaluate the
transformer noise. In the present study, measurements of sound pressure are
described. In this sound pressure measurements are used type-1 sound level
meter which is in accordance with standard IEC 60651 and calibrated with 5.2
article of ISO 3746[8].
According to this, in the condition of forced cooling system is off
the measurement has to be taken 0.3 meters away from the transformer surface.
And the measurement has to be taken 2 meters away from the transformer if the
cooling systems are on. If the tank height is under 2.5
meters the measurement has to be taken from the half of the total tank height. If the tank height is greater than 2.5 meters then the measurement
has to be taken from total tank height's 1/3 and 2/3 heights.
The microphone must be positioned at the stated height and distance.
In addition, a measurement must be taken from at least six microphones. The
horizontal distance between the microphones mustn't be more than 1 meter.
The transformer's A-weighted sound power level and the total of core
noise and load noise under nominal current and voltage is expressed as L_(WA,SN) equivalence 1[8].
L_(WA,SN)=10lg((10)^(0,1L_(WA,UN) )+(10)^(0,1L_(WA,IN) )) (1)
Nominal current, nominal frequency and A-weighted sound power level
of impedance voltage can be calculated with L_(WA,IN) equivalence 2 [8].
L_(WA,IN)≈39+18lg S_r/S_p
(2)
"S" is the area of measurement surface and measured values
gathered from 0.3 meter can be defined with equivalence 3 [8].
S=1,25hl_m (3)
In here "h"
is for the height of the transformer tank and l_m is defined as measurement environment. 1.25
coefficient is a constant derived from experimental observations. Equivalence 4
is used for measurements gathered from 2 meters away[8].
S=(h+2)l_m (4)
Average background noise is defined in L_bg equivalence 5. M is the number of background
measurement point between 1 and 10. L_bgi, i. is the
background sound pressure level measured at the measurement point [9].
(L_bgA ) ̅=10〖log〗_10 (1/M ∑_(i:1)^M▒〖10〗^(0,1L_bgi ) ) (5)
Unadjusted average sound power level is given in L_pAO equivalence 6. N is the number of measurement
points and L_pAi i. is the sound power level in the measurement
point [9].
(L_pAO ) ̅=10〖log〗_10 (1/N ∑_(i:1)^N▒〖10〗^(0,1L_pAi ) ) (6)
After measurement the
second background measurement should be done. If corrected A-weighted sound
pressure level (L_pA ) ̅ , is given in equation 7 [9].
(L_pA ) ̅=10〖log〗_10 (〖10〗^(0,1(L_pAO ) ̅ )-〖10〗^(0,1(L_bgA ) ̅ ) )-K (7)
Finally the
resulting sound power level L_wA , It is defined in equation 8. S, as square meter surface area
measurements and S_0 is reference area. (1m2) [9].
L_wA=(L_pA ) ̅+10〖log〗_10 S/S_0 (8)
B.
Transformers Noise Test Results
In this study, Noise measurement tests which
performed by Turkish Electricity Transmission Company (TEIAŞ), are submitted.
Noise levels are measured as appropriate to international measurement standard(IEC
6006-10). Measurements are performed by with Brüel&Kjaer 2260.
250 MVA autotransformer noise measurements are
given in table III, IV and this transformer’s excitation voltages are chosen 3.675kV
(%100
) and 4.293kV
(%110). Test
frequency is 50 Hz, transformer’s tank height is 3,61 m, microphone heights are
1.2 m and 2.41 m at respectively 1/3 and
2/3 height of the tank. Microphones are placed 2 m away from transformer.
Transformer cooling system is OFAF and during measurement 7 fans and 2 pumps
are service.
) and 4.293kV
(%110). Test
frequency is 50 Hz, transformer’s tank height is 3,61 m, microphone heights are
1.2 m and 2.41 m at respectively 1/3 and
2/3 height of the tank. Microphones are placed 2 m away from transformer.
Transformer cooling system is OFAF and during measurement 7 fans and 2 pumps
are service.
TABLE II
Noıse Pressure of Measurement Area [10]
Position
|
Before the Test
|
After the Test
|
Position
|
Before the Test
|
After the Test
|
1
|
48.3
|
47.3
|
6
|
48.7
|
48.2
|
2
|
49.3
|
47.5
|
7
|
47.1
|
48.2
|
3
|
48.2
|
47.6
|
8
|
47.9
|
48.3
|
4
|
47.4
|
48.0
|
9
|
||
5
|
48.6
|
48.8
|
10
|
||
Arithmetic/Average Energy,
 |
48.2
|
48.0
|
|||
Noise level of
testing environment in before and after of test is measured.
TABLE III
Noise Pressure Levels in 250 MVA
Autotransformer [10]
Sound Pressure Level,
 |
||||||||
Test Voltage: 100%
 ; Measuring Distance, x:
2.0 m; [OFAF, 7 Fans and 2 pumps in service ], MP: Measuring Point |
||||||||
MP
|
Height (h)
|
MP
|
Height (h)
|
MP
|
Height (h)
|
|||
(1/3)
|
(2/3)
|
(1/3)
|
(2/3)
|
(1/3)
|
(2/3)
|
|||
1
|
67.0
|
66.5
|
16
|
67.0
|
66.5
|
31
|
68.7
|
68.3
|
2
|
66.1
|
67.5
|
17
|
66.5
|
66.5
|
32
|
68.5
|
67.5
|
3
|
65.1
|
66.6
|
18
|
65.4
|
65.2
|
33
|
68.7
|
67.4
|
4
|
65.7
|
65.3
|
19
|
65.7
|
66.3
|
34
|
68.2
|
67.8
|
5
|
66.5
|
65.2
|
20
|
66.9
|
66.4
|
35
|
66.9
|
67.6
|
6
|
65.0
|
67.7
|
21
|
66.6
|
66.3
|
36
|
66.5
|
67.8
|
7
|
66.5
|
65.7
|
22
|
67.6
|
67.0
|
37
|
67.6
|
66.4
|
8
|
66.0
|
66.5
|
23
|
68.1
|
67.1
|
38
|
67.4
|
66.7
|
9
|
68.9
|
69.4
|
24
|
68.0
|
67.2
|
39
|
66.4
|
67.5
|
10
|
66.2
|
69.8
|
25
|
67.6
|
67.0
|
40
|
67.3
|
66.1
|
11
|
66.4
|
66.5
|
26
|
66.9
|
66.1
|
41
|
67.3
|
66.5
|
12
|
67.4
|
67.5
|
27
|
67.6
|
66.7
|
42
|
67.5
|
66.7
|
13
|
68.4
|
65.8
|
28
|
67.6
|
66.1
|
43
|
66.4
|
67.2
|
14
|
65.5
|
66.2
|
29
|
68.6
|
67.2
|
44
|
66.4
|
66.5
|
15
|
66.0
|
65.7
|
30
|
68.0
|
67.5
|
|||
Arithmetic/Average
Energy,
 |
67.0 dB(A)
|
|||||||
 (must be greater than 3dB(A)) |
18.9 dB(A)
|
|||||||
Environmental
Correction, K (must be less than 7 dB)
|
6.7 dB
|
|||||||
Corrected
Average Sound Pressure Level,
 |
60.3 dB(A)
|
|||||||
Guaranteed
Sound Pressure Level
|
65.0 dB(A)
|
|||||||
Defined
Peripheral Length
|
44.0
|
|||||||
Area of
the Measurement Surface(OFAF)
|
246.8
 |
|||||||
10lg(S/
 ) |
23.9
|
|||||||
Calculated
Average Noise Power Level,
 |
84.2 dB(A)
|
|||||||
As shown in Table, there is a difference 18.9
dB(A) between total arithmetic average sound pressure and the arithmetic average
sound pressure of test environment. In this transformer 27PHD090 type 0,27 mm thickness
and 30PH105 type 0,30 mm thickness siliceous sheet metals which high
grain oriented (HGO) are used. The magnetic flux density of the relevant
materials is given as (B8[T]) 1,90-1,91 T. With increasing material's B8 value,
magnetostriction acceleration level tends to decrease. It is related to HGO
material to be used and on the reasons of the high B8 value, autotransformer's
core noise is reduced. However, the reason of the noise occurring in
transformer as I mentioned before , with parameters , in addition it may be
remain at high values of no load harmonic currents. Measured no load current
harmonics are given in Table IV.
TABLE IV
Measured
in 250 MVA Autotransformer, No Load Harmonic Currents [10]
Voltage
(kV)
|
Phase
|
Measured (Harmonics)
|
|||
3.
|
5.
|
7.
|
9.
|
||
3.674
|
a1
|
16.8%
|
17.5%
|
10.0%
|
1.0%
|
b1
|
12.1%
|
15.3%
|
8.1%
|
1.8%
|
|
c1
|
23.7%
|
11.3%
|
7.7%
|
3.0%
|
|
In the case of 250 MVA autotransformer’s test voltage %110 , the noise measurements were made in the same
environmental conditions. In this statement, there is a difference 24.8 dB(A)
between the total arithmetic average of sound pressure and the arithmetic
average sound pressure of ambient as it is seen, in case of increasing the test
voltage, approximately 6 dB(A) increase occurred. The measurement results are given in Table V.
, the noise measurements were made in the same
environmental conditions. In this statement, there is a difference 24.8 dB(A)
between the total arithmetic average of sound pressure and the arithmetic
average sound pressure of ambient as it is seen, in case of increasing the test
voltage, approximately 6 dB(A) increase occurred. The measurement results are given in Table V.
TABLE V
In
the case of 250 MVA autotransformer’s test
voltage %110 , occured noise levels[10]
, occured noise levels[10]
Sound Pressure Level,
|
||||||||
Test Voltage: 110%
; Measuring Distance, x:
2.0 m; [OFAF, 7 Fans and 2 pumps in service ], MP : Measuring Point |
||||||||
MP
|
Height (h)
|
MP
|
Height (h)
|
MP
|
Height (h)
|
|||
(1/3)
|
(2/3)
|
(1/3)
|
(2/3)
|
(1/3)
|
(2/3)
|
|||
1
|
71.5
|
72.9
|
16
|
74.0
|
75.8
|
31
|
71.5
|
72.1
|
2
|
70.3
|
72.1
|
17
|
74.1
|
71.7
|
32
|
72.5
|
73.8
|
3
|
71.7
|
71.6
|
18
|
71.7
|
72.6
|
33
|
72.4
|
72.7
|
4
|
71.1
|
72.6
|
19
|
70.7
|
73.1
|
34
|
72.8
|
72.5
|
5
|
72.4
|
74.2
|
20
|
72.7
|
71.5
|
35
|
71.1
|
76.0
|
6
|
72.0
|
74.4
|
21
|
72.1
|
70.2
|
36
|
70.8
|
72.7
|
7
|
75.0
|
74.5
|
22
|
74.0
|
73.6
|
37
|
72.1
|
72.3
|
8
|
74.6
|
74.3
|
23
|
72.6
|
72.6
|
38
|
73.6
|
70.8
|
9
|
75.7
|
76.9
|
24
|
71.0
|
72.1
|
39
|
73.5
|
73.3
|
10
|
73.6
|
72.9
|
25
|
72.9
|
70.8
|
40
|
71.8
|
70.6
|
11
|
73.8
|
77.9
|
26
|
72.1
|
70.3
|
41
|
70.9
|
72.0
|
12
|
75.0
|
74.6
|
27
|
70.6
|
70.9
|
42
|
72.5
|
70.2
|
13
|
74.0
|
72.8
|
28
|
75.0
|
73.3
|
43
|
71.2
|
75.8
|
14
|
71.8
|
76.5
|
29
|
72.6
|
73.0
|
44
|
71.2
|
73.2
|
15
|
71.5
|
70.6
|
30
|
70.8
|
72.6
|
|||
Arithmetic/Average
Energy,
|
72.9 dB(A)
|
|||||||
| (must be greater than 3dB(A)) |
24.8 dB(A)
|
|||||||
Environmental
Correction, K (must be less than 7 dB)
|
6.7 dB
|
|||||||
Corrected
Average Sound Pressure Level,
|
66.2 dB(A)
|
|||||||
Guaranteed
Sound Pressure Level
|
70.0 dB(A)
|
|||||||
Calculated
Average Noise Power Level,
|
90.2 dB(A)
|
|||||||
Rated power which was built by TEIAŞ 50 / 62.5
MVA, the rated voltage of 154 / 33.6 kV and a power transformer cooling system
which is called as ONAN, noise level measurements are taken of the 0.3 m and 2 m distances from the ONAN(cooling
system) are given in Table VI and Table VII.
Noise level of environment which made measurements measured 43.5 dB (A).
TABLE VI
Taken
the Noise Levels in 0.3 m Distance [11]
Sound Pressure of Measurement Area:
43.5 dB(A)
|
|||||||||||
Measuring Distance, x: 0.3 m, MP: Measuring Point
|
|||||||||||
MP
|
Height (h)
|
MP
|
Height (h)
|
MP
|
Height (h)
|
||||||
(1/3)
|
(2/3)
|
(1/3)
|
(2/3)
|
(1/3)
|
(2/3)
|
||||||
1
|
55.4
|
55.4
|
10
|
56.6
|
57.5
|
18
|
55.9
|
55.1
|
|||
2
|
57.0
|
55.7
|
11
|
56.6
|
54.3
|
19
|
53.8
|
54.5
|
|||
3
|
60.0
|
57.7
|
12
|
55.1
|
57.2
|
20
|
57.3
|
54.6
|
|||
4
|
51.0
|
57.1
|
13
|
57.7
|
57.7
|
21
|
59.8
|
55.3
|
|||
5
|
58.7
|
56.4
|
14
|
59.7
|
57.6
|
22
|
56.2
|
54.5
|
|||
6
|
58.2
|
54.2
|
15
|
59.4
|
57.5
|
23
|
54.0
|
54.9
|
|||
7
|
57.1
|
55.8
|
16
|
58.4
|
57.4
|
24
|
58.0
|
54.8
|
|||
8
|
56.5
|
53.2
|
17
|
59.6
|
55.5
|
25
|
53.2
|
53.0
|
|||
9
|
58.7
|
55.5
|
|||||||||
Arithmetic/Average
Energy,
|
1/3h
|
2/3h
|
|||||||||
57.5 dB(A)
|
55.9 dB(A)
|
||||||||||
Environmental
Correction, K (must be less than 7 dB)
|
2.37 dB
|
||||||||||
Corrected
Average Sound Pressure Level,
 |
54.3 dB(A)
|
||||||||||
Guaranteed
Sound Pressure Level
|
60.0 dB(A)
|
||||||||||
Defined
Peripheral Length
|
23.2
|
||||||||||
Area of
the Measurement Surface(OFAF)
|
104.7
 |
||||||||||
10lg(S/
 ) |
20.2
|
||||||||||
Calculated
Average Noise Power Level,
 |
74.5 dB(A)
|
||||||||||
TABLE VII
Taken
the noise levels in 2 m distance [11]
Sound Pressure of Measurement Area:
43.5 dB(A)
|
||||||||||
Measuring Distance, x: 2 m, MP: Measuring Point
|
||||||||||
MP
|
Height (h)
|
MP
|
Height (h)
|
MP
|
Height (h)
|
|||||
(1/3)
|
(2/3)
|
(1/3)
|
(2/3)
|
(1/3)
|
(2/3)
|
|||||
1
|
63.9
|
61.3
|
14
|
62.4
|
62.8
|
26
|
63.8
|
63.3
|
||
2
|
63.4
|
63.1
|
15
|
62.8
|
63.5
|
27
|
63.1
|
63.3
|
||
3
|
63.4
|
63.4
|
16
|
63.8
|
63.3
|
28
|
63.9
|
61.8
|
||
4
|
63.9
|
63.4
|
17
|
63.5
|
63.4
|
29
|
63.4
|
61.4
|
||
5
|
63.8
|
63.5
|
18
|
63.5
|
63.3
|
30
|
63.0
|
61.0
|
||
6
|
63.7
|
63.8
|
19
|
63.5
|
63.4
|
31
|
62.4
|
62.5
|
||
7
|
63.0
|
62.9
|
20
|
63.3
|
63.8
|
32
|
62.2
|
62.9
|
||
8
|
63.9
|
62.3
|
21
|
63.6
|
63.3
|
33
|
61.9
|
63.1
|
||
9
|
62.9
|
61.6
|
22
|
63.0
|
63.3
|
34
|
62.9
|
63.3
|
||
10
|
62.5
|
61.8
|
23
|
63.1
|
63.4
|
35
|
63.7
|
63.4
|
||
11
|
62.0
|
61.7
|
24
|
63.8
|
63.4
|
36
|
63.3
|
63.5
|
||
12
|
63.4
|
61.5
|
25
|
63.2
|
63.1
|
37
|
63.5
|
63.1
|
||
13
|
62.1
|
61.4
|
||||||||
Arithmetic/Average
Energy,
|
1/3h
|
2/3h
|
||||||||
63.2 dB(A)
|
62.9 dB(A)
|
|||||||||
Environmental
Correction, K (must be less than 7 dB)
|
3.86 dB
|
|||||||||
Corrected
Average Sound Pressure Level,
|
59.2 dB(A)
|
|||||||||
Defined
Peripheral Length
|
36.8
|
|||||||||
Area of
the Measurement Surface(OFAF)
|
206.4
|
|||||||||
10lg(S/
) |
23.2
|
|||||||||
Calculated
Average Noise Power Level,
|
82.4 dB(A)
|
|||||||||
IV.
Conclusion
Transformers which are indispensable of power systems are formed on
noise levels should not affect the human health. In this reason, suppression of
noise sources of the transformer constituting the physiological and
psychological effects in humans will play an important role in reducing the
environmental noise. In this study revealed transformer noise sources and
transformer noise measurement methods are described. It was examined and
interpreted noise tests which was given by TEIAŞ.
In the light of detected information, the design
of modern transformers and as a result of the development of materials which is
used core noise (no-load noise) usually ceased to be the dominant noise problem.
Pump and fan noise is not considered as dominant source of noise due to less influence
of noise from no-load condition. Transformer noises' dominant noise source is
usually the load-noise with occurring magnetic leakage flux under load. In this
direction, harmonics which is found in load current must be damped and
transformer mustn’t be overload.
References
[1] A.Ilo, B. Weiser, T. Booth, H. Pfützner,
Influence of Geometric Parameters on the Magnetic Properties of Model
Transformer Cores, 1996
[2] B. Weiser, H. Pfützner, Member, IEEE, and J.
Anger, Relevance of Magnetostriction and Forces for the Generation of Audible
Noise of Transformer Cores, 2000
[3] M. Ishida, S. Okabe, K. Sato, Analysis of
Noise Emitted from Three-Phase-Stacked Transformer Model Core, 1998
[4] Teeraphon Phophongviwat, Wolfson Centre for
Magnetics Cardiff School of Engineering, Investigation of the Influence of
Magnetostriction and Magnetic Forces on Transformer Core Noise and Vibration,
2013
[5] Ramsis S. Girgis, Mats Bernesjö, Jan Anger,
Comprehensive Analysis of Load Noise of Power Transformers
[6] Michael Ertl, Stephan Voss, The Role of Load
Harmonics in Audible Noise of Electrical Transformers, 2014
[7] R.S. Ming, J. Pan, M. P. Norton, S. Wende,
H. Huang, The Sound-Field Characterisation of a Power Transformer, 1999
[8] IEC 60076-10, Power Transformers-Part 10:
Determination of Sound Levels, 2001
[9] Ake Carlson, Jitka Fuhr, Gottfried Schemel,
Franz Wegscheider, Testing of Power Transformers, 2003
[10] TEİAŞ 250 MVA Ototransformatörün Gürültü
Ölçümü, 2012
[11] TEİAŞ 50/62,5 MVA Güç Transformatörünün
Gürültü Ölçümü, 2011
Erdi Dogan was born in Elazıg, Turkey, in
1989. He graduated in electrical and electronic engineering at the Fatih
University, Turkey in 2011. In 2015 he joined Turkish
Electricity Transmission Company(TEİAŞ) in Erzurum, Turkey and he is currently
working as an electrical engineer at the Load Distribution Manager. He is
currently studying master of science in electrical engineering at Yildiz
Technical University, Turkey.
His research interests power
transformes, power transmission system and power quality.
Bedri
Kekezoglu was born in Istanbul, Turkey, in 1982. He
is currently working as an Assistant Professor at the Electrical Engineering
Department of Yildiz Technical University, Turkey.
His research interests include analysis
of power systems, wind energy systems and power quality.
E. Dogan is with Turkish Electricity Transmission Company, Turkey, (corresponding
author to provide phone: +90-0442 242 27 58 e-mail: edoganenerji@ gmail.com).
B. Kekezoglu is with Electrical
Engineering Department, Yildiz Technical University, Istanbul, TURKEY (,
e-mail: bkekez@ yildiz.edu.tr).
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