Sample of EMF for communication equipment vs home appliance
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an informative project on types of transformers and their efficienciesFull description
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This is the Generator section from the July 1956 edition of the DKW 3=6 Spare Parts Catalogue. This would be applicable to the DKW F91 cars
mediciones técnica en contenedores norma IICL6Full description
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Investigatory Project Report on Transformers for Class XII CBSE Including Certificate, Acknowledgement & Index. It possesses all the requirements for a complete project and you can score …Full description
Fi el eld dE Ex x p er erii en ence ce i n SFRA Measurement o n Ge nerat on nera ne ratt o orr Trra rans ansf ans nsforme fformers orm e rrs s EuroDoble Conference 2009 A. Saravanakumar
M. Boltze
S. Markalous
Doble LDIC
Doble LDIC
Doble LDIC
Germany
Germany
Germany
Outline • • Principle of SFRA • Sample results
Diagnostic Testing Method • Monitorin – Sensor development – Data acquisition, noise suppression, filtering • Diagnosis – Interpretation of monitored data • Bene its – Reduced risk of failure, better asset management –
DTCM Methods I nsulat ion Syst em
Winding/ cor e ar r angem ent
Partial discharge
Leakage reactance
Dissolved gas analysis
Low voltage impulse test
Top oil temperature
Transfer function method
Degree of polymerisation
Sweep Frequency Response Analysis
Furan analysis Recovery voltage Insulation resistance tan(δ) or loss factor
-200 Direct f requency domain measurement ( SFRA) 200
0.4
) 100 g e d ( 0 e s a h P-100
0.3
e d u t i n0.2 g a M
0.1 0 0
600
Time domain data deconvoulted in frequency domain (TF method) 200
0.1
V ( f )
900
-5
e d u0.2 t i n g a M
I n( f )
800
Neutral Current (mA)
0.3
H ( f ) =
700
0
-10 0
in(t )
600
500
1000 Frequency (kHz)
1500
2000
-200 0
500
1000 1500 Frequency (kHz)
2000
Principle of SFRA • • • • •
Apply spectrally pure sinusoidal signal Measure excitation and response Compute and store Gain/phase Repeat measurement at next screte requency Direct frequency domain measurement
• • •
interference Sensitive in detecting winding/core movement An Draft on IEEE Guide for performing SFRA exists
Practical difficulties • • • • •
Ensure s ectral urit of source Source harmonics exist & introduce problems Excitation level low; SNR problem for on-site Influence of cable length, bushing capacitance Unshielded connecting leads cause problems
Typical Response of winding Magnitude
+ 90◦
- 90◦
Admittance – Y(f)
SFRA and Natural frequencies Equivalent circuit representation of a two winding single phase transformer
• Several factors affect natural frequency – Winding type, position, arrangement, clearance and termina connection – Terminal connection is the only factor that can be • Some natural frequencies are non-excitable under certain • Knowledge of all natural frequencies indicates highest sensitivit
Influence of Terminal Conditions 1
(a) - Excitation with respect to ground
1
(b) - Excitation with respect to ground HVSC/Y(f)
2
0.8
0.8
3
) u . p0.6 ( g a0.4 M
0.2
1
HVOC/Y(f)
4 2
u . 0.6 p ( g a0.4 M
7 8
5
3 6
0.2
4
6
0 1
0 (c) - Excitation with respect to neutral HVOC/Y(f)
1
0.8
0 0
1
HVSC/(Yf)
0.8
) u . . p ( g a0.4 M
0.2
(d) - Excitation with respect to neutral
3
) . . p ( g a0.4 M
0.2
1
500
1000 1500 Frequency (kHz)
2000
0 0
500
1000 1500 Frequency (kHz)
2000
Fig. 1 Measured amplitude frequency response pertaining to terminal connection where non tested windings are – (a), (c) open circuited and floating (b), (d) shorted and floating
Pole-Zero 5
) s / a r 0 M ( ω
-5 -0.1
) s / d a r
M (
-0.09
-0.08
-0.07
-0.06
-0.05 -0.04 σ (Mneper/s)
-0.03
-0.02
-0.01
0
0.01
-0.09
-0.08
-0.07
-0.06
-0.05 -0.04 σ (Mneper/s)
-0.03
-0.02
-0.01
0
0.01
0
ω
-0.1
.
-
.
All System Function Terminal Condition 1 g a 0.5 M
0 1 g M
2
1
2
1
5
3
4
7 6
4
3
5
9 6
7
. 0 1
g a 0.5 M
0 0
10
8
10
11
Ig( ω )/Ip(ω )
12
11
Vp(ω )/Ip(ω )
1
g a 0.5 M
0 1
8
9
Ip( ω )/Vp(ω ) 2
4
5
6
8
9
10
1 2
100
3
4 200
300
400 500 600 Frequency (kHz)
5 700
800
900
1000
Cable Terminations 1
(a)
1
Vout(f)/Vin(f)
0.8 ) u . 0.6 p ( g a0.4 M
6 2
3
8
5 4
9
7
0.2
10
0 1
(b)
1
0.8
Vout(f)/Vin(f)
) . . p ( g a0.4 M
2
0.2 0 0
3 100
4 200
5
6 300
7 400
500 600 Frequency(kHz)
700
800
900
1000
Measured amplitude frequency response pertaining to terminal connection where non tested windings are open circuited – (a) 50 Ω(b) 1 MΩ termination
Dynamic Range (a)
3
1.5
Vout(f)/Vin(f) ) u . p (
1
1
4
g a M
2
0.5
9
7 0
(b) 3
1.5 ) u . p ( g a M
1
Vout(f)/Vin(f) 1 4
0.5
2 5
0 0
100
200
6 300
8
7 400
9
500 600 Frequency(kHz)
700
800
900
1000
Measured amplitude frequency response from a single phase two winding –
DOBLE SFRA EQUIPMENT • Voltage – 10 V p-p (at 50 Ω im edance • Frequency range – 10 Hz to 10 MHz – • Input/Output impedance – 50 Ω
•
– (logarthmically placed) • Three lead measuring system
Current practice (Doble)
¾Tested
winding - Exciting Phase / Line end - Neutral (1 – phase) - Phase (3 – phase/ ∆ ) - Neutral (3 – phase/ Y) on teste w n ng - Open circuited - Short circuited ¾Non tested terminals are floatin
Test and Analysis • At factory – Before and after any destructive testing (like short circuit strength assesment test) – Routine test Baseline data • At Field – Routine test (after installing) – – After any major event • Analysis – With baseline data – Phase to phase – Sister unit measurements
General Guideline Screen captured from DOBLE SFRA ANALYZER (M5200) SC response
OC response Magnitude
Core Influence Bulk movement (Core/winding)
Phase
Bushing, lead movement and so on
Characterstics of windings Open circuit response measured from 60 MVA, 128.36 / 20 kV transformer
H2 / Middle phase H3 / Outer phase
Comparison of outer phases (H1 and H3)
Comparison of middle phase with outer phase (H2 and H3)
Measurable Parameters Open circuit response Exciting current
Inductance DC winding
Leakage reactance
or c rcu response
Certain type of faults • With and without oil – spectrum remains same with • Bad ground – shows notable differences at high frequencies (f>1 MHz)
