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7UT8x Intro

22

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Sheik Hussain
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0% found this document useful (0 votes)
305 views22 pages

7UT8x Intro

22

Uploaded by

Sheik Hussain
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 22

Overview and Applications

SIPROTEC 5
7UT8x

© Siemens AG 2013 All rights reserved. Answers for infrastructure and cities.
SIPROTEC 5
Transformer differential protection devices

Two winding transformers 7UT82


(2 sides, 2 measuring points)

non expandable HW
ƒ 1 differential protection for standard
and auto transformers

ƒ 2 restricted earth fault protections

ƒ Number of measuring points (MP)


ƒ 2 three phase current MPs
ƒ 2 single phase current MPs

ƒ 1/3 Device with IO103

© Siemens AG 2012. All rights reserved.


Page 2 Energy Automation Sector Infrastructure & Cities
SIPROTEC 5
Transformer differential protection devices

Two winding transformers 7UT85


(2 sides, 4 measuring points)

expandable
ƒ 1 differential protection for standard
and auto transformers

ƒ 2 restricted earth fault protections

ƒ Number of measuring points (MP)


ƒ 4 three phase current MPs
ƒ 3 single phase current MPs
ƒ 2 three phase voltage MPs

© Siemens AG 2012. All rights reserved.


Page 3 Energy Automation Sector Infrastructure & Cities
SIPROTEC 5
Transformer differential protection devices

Three winding transformers 7UT86


(3 sides, 6 measuring points)

expandable
ƒ 1 differential protection for standard
and 2 for autotransformers

ƒ 3 restricted earth fault protections

ƒ Number of measuring points (MP)


ƒ 6 three phase current MPs
ƒ 4 single phase current MPs
ƒ 3 three phase voltage MPs

© Siemens AG 2012. All rights reserved.


Page 4 Energy Automation Sector Infrastructure & Cities
SIPROTEC 5
Transformer differential protection devices

Multiple winding transformers 7UT87


(7 sides, 9 measuring points)

ƒ Multiple winding differential protection


expandable
ƒ 3 differential protections for standard and
autotransformers

ƒ 5 restricted earth fault protections

ƒ Number of measuring points (MP)


ƒ 9 three phase current MPs
ƒ 5 single phase current MPs
ƒ 3 three phase voltage MPs

© Siemens AG 2012. All rights reserved.


Page 5 Energy Automation Sector Infrastructure & Cities
SIPROTEC 5
Transformer differential protection devices

Protection functions
7UT8x
ƒ Transformer Differential protection
ƒ Restraint characteristic and fast trip stage
ƒ Flexible vector group adaptation
ƒ Inrush and over excitation detection
ƒ CT saturation detection

ƒ Motor differential protection

ƒ Restricted earth fault protection

ƒ Thermal overload protection

ƒ Sensitive E/F protection

© Siemens AG 2012. All rights reserved.


Page 6 Energy Automation Sector Infrastructure & Cities
SIPROTEC 5
Transformer differential protection devices

Protection functions
7UT8x
ƒ Directional O/C protection

ƒ Voltage and frequency protection

ƒ Distance protection

ƒ Tap changer

ƒ Voltage regulator

ƒ Adaptive differential protection (considering the tap position)

ƒ Line Differential protection (together with 7SD8, 7SL8, 7UT8)

© Siemens AG 2012. All rights reserved.


Page 7 Energy Automation Sector Infrastructure & Cities
Integrated Line Differential Protection

7UT
8x
87 T

Protection
interface
87 L

7SD
8x

© Siemens AG 2012. All rights reserved.


Page 8 Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Improved restraint algorithm

ƒ High sensitivity also at low fault currents Idiff IMP1 IMP2


requirement
Customer

ƒ Sensitivity at 1,5 CB application with


small power transformers
trip area
ƒ High stability against external faults
IMP3
ƒ 87T uses the conventional restraint
restraint
Siemens
solution

characteristic with modified settings Idiff> Idiff = |Ρ IMP |


area
ƒ New is the calculation of the restraint Irest = Max {ΗMP|
Irest
current (Maximum of the phase currents)

ƒ 87T restraint characteristic has three ƒ Higher sensitivity in 1,5 CB


straight lines application
ƒ Flexible setting of the characteristic ƒ More stability at signal distortion
functions

Benefits
Device

(e.g. CT saturation)
ƒ Increased system availability

⇓ Increased system availability


© Siemens AG 2012. All rights reserved.
Page 9 date Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Improved Idiff- fast stage

ƒ Short tripping time at high internal fault IMP1 IMP2


requirement

Idiff
Customer

currents
ƒ Robust at CT saturation (internal faults) trip area

ƒ Stable at external faults in 1,5 CB appl. Idiff>>

k=0,8 IMP3
ƒ 87T fast stage evaluates instantaneous
values of the differential current i(t)diff = |Ρ iMP(t) |
Siemens
solution

ƒ New: Fast differentiation between i(t)rest = Max {iMP(t)|


internal and external fault based on few Irest
idiff, irest trajectory
samples (proven busbar prot. method) evaluation

ƒ 87T fast stage in addition to the ƒ Fast tripping time at internal faults
standard restraint characteristic also at saturated currents
ƒ Adaptive algorithm for differential ƒ Stable at heavy external faults with
functions

Benefits
Device

current evaluation: first instantaneous CT saturation (transverse currents


values and after 1 cycle filtered values in 1,5 CB application)

⇓ Increased system availability


© Siemens AG 2012. All rights reserved.
Page 10 date Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Improved inrush stabilization

ƒ Stable at inrush currents (switching ON


requirement
Customer

of a transformer)
ƒ Stable at sympathetic inrush currents
(switching ON of a parallel transformer) IMP1 IMP2

Method 1: I2,Harm/I1,Harm > 15%


ƒ Inrush detection function blocks the Method 2: CWA ⇓ Flat area evaluation
Siemens
solution

differential protection
ƒ New is the one out of two decision of
two different inrush algorithms

ƒ Inrush detection function with two ƒ Avoiding of false trip in the case of
different measuring principles an inrush or sympathetic inrush
ƒ Second harmonic evaluation with ƒ Increased system availability
functions

Benefits
Device

the cross block option


ƒ Curve waveform analysis (CWA)
ƒ At high VTR blocking of the differential
protection with the 5th harm. current
⇓ Increased stability at inrush currents
© Siemens AG 2012. All rights reserved.
Page 11 date Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Faster detection of external faults

ƒ Protection must be stable at external Idiff


requirement
Customer

faults with CT saturation


ƒ CT requirements regarding transient CT = ?
trip area
performance must be as low as possible

IMP1 IMP2
ƒ New algorithm based on instantaneous
Siemens
solution

values detects very fast external faults Idiff> Add-on Stabilization

ƒ Missing samples due to saturation are


Irest
predicted via an estimation method

ƒ Add-on stabilization characteristic for ƒ Stable at external faults with CT


external fault detection with CT saturation
saturation ƒ Lower CT requirements
functions

Benefits
Device

ƒ Handling of evolving faults (if after an ƒ Secure handling of evolving faults


external fault an internal occurs) ƒ Increased system availability
ƒ Reduced transient dimensioning factor
(Ktd = 2; SIP4-factor was 3
⇓ Cost reduction through lower CT requirements
© Siemens AG 2012. All rights reserved.
Page 12 date Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Wide range of CT mismatching

ƒ Using of protection on 3-wind. with a low


requirement
Customer

power tertiary winding or 2- wind. transf.


with high ISC on the busbar
ƒ Matching transformers must be avoided I CT
< 10
I OBJECT

ƒ High resolution of the measured phase


Siemens
solution

currents via 24 ADC


ƒ Each measured current can be adapted
ICT
to a reference current < 0,104
I OBJECT

ƒ No limitation regarding CT mismatching ƒ Improved transient CT


performance via lower burden
⇓ No matching transformer
functions

Benefits
Device

ƒ Flexible applications

⇓ Increased application flexibility


© Siemens AG 2012. All rights reserved.
Page 13 date Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Two winding transformer

Requirement
ƒ Two winding transformer differential protection
ƒ additional functions
ƒ Protection with one device only
ƒ Flexible hardware and communication

Solution
ƒ Transformer differential device 7UT85
ƒ Standard hardware (base module)
ƒ Application template: Two winding basic
ƒ Communication modules

Benefit
ƒ One device for different applications, easy adaptation
ƒ Simplified engineering, reduced wiring, shorter
commissioning
© Siemens AG 2012. All rights reserved.
Page 14 Energy Automation Sector Infrastructure & Cities
Application template:
Two winding transformer basic

© Siemens AG 2012. All rights reserved.


Page 15 Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Two winding transformer and REF

Requirement
ƒ Two winding transformer differential protection
ƒ additional functions
ƒ High sensitivity at 1-phase ground faults
ƒ Protection with one device only

Solution
ƒ Transformer differential device 7UT85
ƒ Functions 87T and 87T N
ƒ Standard hardware (base module)
ƒ Application template: Two winding with REF

Benefit
ƒ One device for different applications, easy adaptation
ƒ Simplified engineering, reduced wiring, shorter
commissioning

© Siemens AG 2012. All rights reserved.


Page 16 Energy Automation Sector Infrastructure & Cities
Application template:
Two winding transformer with REF

© Siemens AG 2012. All rights reserved.


Page 17 Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Two winding transformer in 1.5 CB

Requirement
ƒ Two winding transformer differential
protection in 1.5 CB application
ƒ High sensitivity at 1-phase ground faults
ƒ Protection with one device only

Solution
ƒ Transformer differential device 7UT85
ƒ Functions 87T and 87T N
ƒ Standard hardware (base + expansion
module)
ƒ Application template: Two winding for 1,5
CB application

Benefit
ƒ One device for different applications, easy adaptation
ƒ Simplified engineering, reduced wiring, shorter
commissioning
© Siemens AG 2012. All rights reserved.
Page 18 Energy Automation Sector Infrastructure & Cities
Application template:
Two winding transformer 1,5 CB

52 52
B-QA A-QA FG Transformer side 1 FG Circuit breaker A-QA
MP
I-3ph I-3ph 50BF
I-3ph 1
49 87N Ctrl
MP
I-3ph 2 Measured values
BI
CB
BO

FG Transf. neutral point 1 FG Transformer 1 FG Circuit breaker B-QA

I-1ph I-3ph 50BF


MP
50N 51N 87 Ctrl
I-1ph 1
Measured values
BI
CB
BO

FG Transformer side 2 FG Circuit breaker C-QA


MP
I-3ph I-3ph 50BF
I-3ph 3
50 51 Ctrl

52 C-QA Measured values


BI
CB
BO

© Siemens AG 2012. All rights reserved.


Page 19 Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Three winding transformer

Requirement
ƒ Three winding differential protection for different
vector groups
ƒ Protection with one device only
ƒ Flexible hardware and communication

Solution
ƒ Transformer differential device 7UT86
ƒ Standard hardware (base + expansion module)
ƒ Application template: Three winding basic

Benefit
ƒ One device for different applications, easy adaptation
ƒ Simplified engineering, reduced wiring, shorter
commissioning

© Siemens AG 2012. All rights reserved.


Energy Automation Sector Infrastructure & Cities
Transformer differential protection 7UT8
Three winding transformer in 1,5 CB

Requirement
ƒ Three winding differential protection for 1,5 CB
application
ƒ High sensitivity at 1-phase ground faults
ƒ Protection with one device only
ƒ Flexible hardware and communication

Solution
ƒ Transformer differential device 7UT86
ƒ Standard hardware (base + expansion module)
ƒ Application template: Three winding for 1,5 CB
application

Benefit
ƒ One device for different applications, easy adaptation
ƒ Simplified engineering, reduced wiring, shorter
commissioning

© Siemens AG 2012. All rights reserved.


Energy Automation Sector Infrastructure & Cities
7UT86- Application template
Three winding transformer for 1,5 CB application

52 52
B-QA A-QA FG Transformer side 1
MP
I-3ph
I-3ph 1 FG Circuit breaker A-QA
49 87NT
MP I-3ph 50BF
I-3ph 2
V-3ph 59 81 Ctrl
MP
Measured values
V-3ph 1 BI
CB
BO

FG Transf. neutral point 1 FG Circuit breaker B-QA


MP
I-1ph I-3ph 50BF
I-1ph 1
50N 51N Ctrl

Measured values
BI
CB
BO

FG Transformer side 2 FG Transformer 1 FG Circuit breaker C-QA


MP
I-3ph I-3ph 50BF
I-3ph 3
Ctrl
87T
Measured values
BI
CB
BO

FG Transformer side 3 FG Circuit breaker D-QA


MP
I-3ph I-3ph 50BF
I-3ph 4
Ctrl
52 52
Measured values
D-QA C-QA BI
CB
BO

© Siemens AG 2012. All rights reserved.


Page 22 Energy Automation Sector Infrastructure & Cities

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