7UT61X Transformer Protection

Module 10B: Transformer Protection The year of Profitable Growth

Global network of innovation

Power Transmission and Distribution

Commissioning and operating aids (4 of 5) Power Automation Progress. It‘s that simple.

Generator transformer SITRAM+ Siemens Transformer Monitoring System for all voltage levels

Shunt reactor

HVDC

System interconnecting transformer

FACTS Converter transformer

Furnace transformer

System transformer

Oil-immersed distribution transformer

Voltage regulator

GEAFOL cast-resin transformer

TLM50+ Siemens Transformer Life Management Program

Traction transformer

Power Automation

2

Power Transmission and Distribution

575-MVA Phase Angle Regulator (PAR) Transformer Set in the 345 kV Station Power Automation Progress. It‘s that simple.

Power Automation

3

Power Transmission and Distribution

630-kVA Oil-Immersed Distribution Transformers, TUMETIC, TUNORMA Power Automation Progress. It‘s that simple.

Power Automation

4

Power Transmission and Distribution

Transformer Prices Power Automation Progress. It‘s that simple.

>40 MVA 10,-US$ pro kVA => 30MVA = 40.000 kVA *10 US$ = 300.000US$ >200 MVA 8,-US $ pro kVA => 200 MVA 200.000kVA *8 US$ = 1’600.000US$

>1000 MVA 5,-US$ pro kVA => 1000 MVA 1000.000kVA *5 = 5’000.000 US$ Power Automation

5

Power Transmission and Distribution

TLM50+ – Siemens Transformer Life Management Program Power Automation Progress. It‘s that simple.

SIDRY, SMART DRY, SIREC advanced life extension programs

SITRAD Condition assessment program

Traditional heat and vacuum treatment

On-site services and repair SITRAM+ transformer monitoring system Power Automation

6

Power Transmission and Distribution

Transformer Faults Power Automation Progress. It‘s that simple.

Power Automation

7

Power Transmission and Distribution

The 7UT6 Family Power Automation Progress. It‘s that simple.

SIPROTEC 4 7UT6 differential protection relay for transformers, generators, motors and busbars

7UT612: 7UT613: 7UT633: 7UT635:

for two end protection objects for three end protection objects for three end protection objects for five end protection objects

(1/3 x 19’’ housing 7XP20) (1/2 x 19’’ housing 7XP20) (1/1 x 19’’ housing 7XP20) (1/1 x 19’’ housing 7XP20) Power Automation

8

Power Transmission and Distribution

Hardware options Power Automation Progress. It‘s that simple.

*

Device

7UT612

7UT613

7UT633

7UT635

Current Inputs (normal) Current Inputs (sensitive) Voltage Inputs (Uph / UE) Binary Inputs Binary Outputs Life contact LC Display

7 (7)* 1 --3 4 1 4 lines

11 (6)* 1** 3/1 5 8 1 4 lines

11 (6)* 1** 3/1 21 24 1 Graphic

14 (12)* 2** --29 24 1 Graphic

1A, 5A, (1A, 5A, 0.1A) changeable (jumper position)

** changeable normal or sensitive (jumper position)

Power Automation

9

Power Transmission and Distribution

Scope of functions and Protection objects Power Automation Progress. It‘s that simple.

Function

ANSI No.

Protection Objects

Differential

87T/G/M/L

Three-phase transformer

Restricted Earth fault

87 N

Single-phase transformer

Overcurrent-time, phases

50/51

Auto-transformer

Overcurrent-time, 3I0

50N/51N

Generator / Motor

Overcurrent-time, earth

50G/51G

Busbar, 3-phase (Branch point)

Overcurrent-time, single phase

Busbar, 1-phase

Negative sequence

46

Overload IEC 60255-8

49

Overload IEC 60354 (hot spot)

49

Overexcitation V/Hz

24

Breaker failure

50BF

External temperature monitoring

38

Lockout

86

Measured value supervision Trip circuit supervision

74TC

Direct coupling Operational measured values

Power Automation

10

Power Transmission and Distribution

Cross reference - functions and protected objects Power Automation

Protection functions

ANSI No.

Transf. 3-phase

Transf. 1-phase

Autotransf.

Gen. / Motor

Busbar 3-phase

Busbar 1-phase

Differential

87T/G/M/L

X

X

X

X

X

X

Restricted Earth Fault

87 N

X

X

---

X

---

---

Overcurrent-time, phases

50/51

X

X

X

X

X

---

Overcurrent-time, 3I0

50N/51N

X

---

X

X

X

---

Overcurrent-time, earth

50G/51G

X

X

X

X

X

X

X

X

X

X

X

X

Progress. It‘s that simple.

Overcurrent-time, single phase

Negative sequence

46

X

---

X

X

X

---

Overload IEC 60255-8

49

X

X

X

X

X

---

Overload IEC 60354

49

X

X

X

X

X

---

24

X

X

X

X

X

X

Breaker failure

50 BF

X

X

X

X

X

---

External temperature monitoring (thermo-box)

38

X

X

X

X

X

X

Lockout

86

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Direct coupling 1

X

X

X

X

X

X

Direct coupling 2

X

X

X

X

X

X

Operational measured values

X

X

X

X

X

X

Overexcitation V/Hz

*)

Measured value supervision Trip circuit supervision

X Function applicable ;

74TC

--- Function not applicable ;

*) only 7UT613 / 633 Power Automation

11

Power Transmission and Distribution

Communication features Power Automation

Flexibility due to plug in modules

Progress. It‘s that simple.

Compatibility to international standards

RS232/RS485 electrical module

Front interface DIGSI4

WEB Monitor

Service interface (s) Fibre-optic module

Optical double-ring module

DIGSI4 operation modem connection RTD box

System interface IEC60870-5-103 Profibus FMS Profibus DP DNP3.0 Modbus ASCII/RTU

Time synchronising IRIG-B (GPS) DCF77

Power Automation

12

Power Transmission and Distribution

Connection Example M3 L1

Power Automation Progress. It‘s that simple.

side 3

L2

direct connection to the main Ct’s

L3

L1

M2

side 2

side 1

M1 L1

L2

L2

L3

L3

no matching transformers / no matching connections numerical vector group adaptation without zero sequence current correction depending of the type of earthing of the winding. increased sensitivity by 33% by measuring of the zero sequence current (7UT6) for single-pole faults.

IL1M2

IX1

IX3

IL1M1

IL2M2

IL2M1

IL3M2

IL3M1

1A/5A main Ct’s adaptation in the relay

permissible ratio Ct nominal current to transformer nominal current up to 1 : 4

IL1M3

Surface mounting housing

IL2M3

Flush/ cubiclemounting housing

IL3M3

7UT613 Power Automation

13

Power Transmission and Distribution

Application: 3-winding transformer YNd5d11 (1 of 4) Power Automation

IL1M1/I1

Progress. It‘s that simple. M1

IL2M1/I2

M2 400/1A M1 400/1A

IL3M1/I3 IL1M2/I4

M3 400/1A M2

IL2M2/I5 IL3M2/I6 IL1M3/I7

M3

IL2M3/I8 IL3M3/I9

M5 3500/1A

Side 1 200/1A

IL1M4/I10 M4

IL2M4/I11

IL3M4/I12

Side 3

Side 2

IL1M5/Ix1

M5

IL2M5/Ix2

M4 8000/1A

IL3M5/Ix3 Ix4

7UT635 Power Automation

14

Power Transmission and Distribution

Application: 3-winding transformer YNd5d11 (2 of 4) -Device Configuration and Power System Data 1 Power Automation Progress. It‘s that simple.

7UT635

Power Automation

15

Power Transmission and Distribution

Application: 3-winding transformer YNd5d11 (3 of 4) -continue Power System Data 1 Power Automation Progress. It‘s that simple.

7UT635

Power Automation

16

Power Transmission and Distribution

Application: 3-winding transformer YNd5d11 (4 of 4) -continue Power System Data 1 Power Automation Progress. It‘s that simple.

7UT635

Power Automation

17

Power Transmission and Distribution

Application: Autotransformer with ∆ Winding (1 of 2) Power Automation Progress. It‘s that simple.

M1

Side 1

M2

Side 3

M3

Side 2

IL1M2

IL1M3

IL2M2

IL2M3

IL3M2

IL3M3

IL1M1

IL2M1

IL3M1

7UT613 Power Automation

18

Power Transmission and Distribution

Application: Autotransformer with ∆ Winding (2 of 2) - Power System Data 1 Power Automation Progress. It‘s that simple.

7UT613

Power Automation

19

Power Transmission and Distribution

Application: Autotransformer with ∆ Winding (2 of 2) - Power System Data 1 Power Automation Progress. It‘s that simple.

Power Automation

20

Power Transmission and Distribution

Application: Autotransformer (bank) with 3 Ct’s at the star point side available Power Automation Progress. It‘s that simple.

(1 of 2)

M3

M1

Only compensation winding, no external connection!

M2

Increased sensitivity for phase to phase- and phase to ground faults towards the star point!

7UT613 Power Automation

21

Power Transmission and Distribution

Application: Autotransformer (bank) with 3 Ct’s at the neutral side

(2 of 2)

Power Automation Progress. It‘s that simple.

7UT613

Power Automation

22

Power Transmission and Distribution

Application: Single-phase bus bar (1/2) - Phase selective configuration (1 7UT6 for 1 phase) Power Automation Progress. It‘s that simple.

7UT612: 7 currentinputs 7UT613/633: 9 currentinputs 7UT635: 12 currentinputs

7UT612

Power Automation

23

Power Transmission and Distribution

Application: Single-phase bus bar (2/2) - Phase selective configuration (1 7UT6 for 1 phase) Power Automation Progress. It‘s that simple.

7UT612

2 more Relays for Phase 2 and 3 are necessary

Power Automation

24

Power Transmission and Distribution

Application: Single-phase bus bar - configuration with Summation Ct’s

(1 of 2)

Power Automation Progress. It‘s that simple.

7UT612: 7 currentinputs 0.1A 7UT613/633: 6 currentinputs 0.1A

7UT635: 12 current inputs 0.1A

*) Summation CT 4AM5120-3DA00-0AN2: 1/0.1A 4AM5120-4DA00-0AN2: 5/0.1A

7UT612

Power Automation

25

Power Transmission and Distribution

Application: Single-phase bus bar - configuration with Summation Ct’s

(2 of 2)

Power Automation Progress. It‘s that simple.

7UT612

Not important in this case

Power Automation

26

Power Transmission and Distribution

General Applications of 2)

(1

Power Automation Progress. It‘s that simple.

Two winding transformer 1 or 3 phases

Three winding transformer 1 or 3 phases

1 ½ C.B. application with two winding transformer

7UT613 7UT633 7UT612 7UM62

Short lines (2 ends)

7UT613 7UT633

Short lines (3 ends)

1 ½ C.B. application on HV and LV side with two winding transformer

7UT635

7UT612

7UT613 7UT633

Power Automation

27

Power Transmission and Distribution

General Applications of 2)

(2

Power Automation

Generator/Motor longitudinal or transversal differential protection

High-impedance Restricted Earth Fault Protection

G/M 3~

7UT612 7UM62

7UT6xx

Unit Protection (Overall Differential)

IEE input of the unit

Y

Progress. It‘s that simple.

7UT635

∆

G 3~

Power Automation

28

Power Transmission and Distribution

Differential functions IDiff> and IDiff>> Power Automation

measured value pre-processing ( vector gr. ,Ct’s )

Progress. It‘s that simple. i1L

Instantaneous values iRest = │i1│ + │i2│

side 1

i2L

iDiff = i1 + i2

side 2

rectified mean value: IRest = iRest fundamental wave: IDiff = rms(iDiff)50Hz

Tripping characteristic, saturation detection IDiff IDiff>

IRest

&

Trip IDiff>

≥1

Trip IDiff>>

Motor start DC off set analysing of harmonics: -block by 2. & 3. or 5.har -cross block iDiff

iRest IRest

IDiff

IDiff I / InO

I / InO

IDiff>>

ms

iDiff 2·IDiff>> ms

IDiff> restrained (biased) differential function, IDiff> = f(IRest) - Ct-saturation detector (add on stabilization) for external faults. IDiff>> fast unrestrained high current differential function, it’s setting therefore should be higher then the maximum possible through flowing current! Example Transformer: IDiff>> > (1/uk)·InO This function will be not blocked by harmonics due to an inrush or Ct-saturation! The IDiff>> stage evaluates the fundamental wave of the currents as well as the instantaneous values. - Fundamental wave processing: fast tripping at the set threshold. - Instantaneous value processing: ensures fast tripping even in case the fundamental wave of the current is strongly reduced by Ct-saturation. Because of the possible DC offset after fault inception, the instantaneous value stage operates only above twice the set threshold. Power Automation

29

Power Transmission and Distribution

Tripping Characteristic Reasons for this shape of characteristic Power Automation Progress. It‘s that simple.

x

I Diff InO 3.0

2.5 Trip

Slope 2 Total

2.0

Block 1.5

CTerror

1.0

Slope 1

Tapchanger

0.5 IDiff> 0

Magnet. current 0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

I Rest InO

Example: Transformer with Tap changer

Power Automation

30

Power Transmission and Distribution

Tripping Characteristic of 2) Power Automation Progress. It‘s that simple.

Tripping Characteristic 7UT6

I Diff InO 1231 IDiff>>

(1

7 1243A SLOPE 2

6 45°

5

Block

Trip 4

*) 3 2

Add-on Stabilization

1241A SLOPE 1

1 1221 IDiff>

0

0

2

4

6

1242A 1256A BASE POINT 1 I-ADD ON STAB 1244A BASE POINT 2

8

10

12

14

16

*) Slope for Add-on Stabilization: 7UT6  Slope 1 ; 7UT5  ½ Slope 1

I Rest InO

flexible adaptation to various transformers, e.g. with tap changer or different Ct’s high stability against external faults with Ct saturation IDiff>>: fast tripping for solid short-circuits within one period Power Automation

31

Power Automation

Tripping Characteristic of 2) - Parameters

Power Transmission and Distribution

(2

Progress. It‘s that simple.

7UT6: settable 7UT5: 0 (fixed) 7UT6 only min. setting: 7UT6: 3 ; 7UT5: 5 7UT613 / 63x

Power Automation

32

Power Transmission and Distribution

Tripping Characteristic - Pickup of differential function Power Automation Progress. It‘s that simple.

For triggering of internal tasks, events and fault records the differential protection function needs a pickup information. This pickup becomes active, if the differential current or the restraint current is over an internal threshold (dotted line). Each external large current leads to a pickup. Pickup doesn‘t always mean internal failure! Power Automation

33

Power Transmission and Distribution

Tripping Characteristic - Add on stabilization during external fault Power Automation Progress. It‘s that simple.

During an external fault which produces a high through-flowing current, causing Ct saturation, a considerable differentialcurrent can be simulated, especially when the degree of saturation is different at the two sides. If the quantities IDiff/IRest result in an operating point which lays in the trip area of the operating characteristic, a trip signal would be the consequence, if there were no special measures

Tripping Characteristic 7UT6

I Diff InO IDiff>>

(1 of 2)

7

Trip 6 45°

Block

5 D C

4 3

Add-on Stabilization

2

1 Saturation inception

B

IDiff>

0 0 A

2

4

6

8

10

12

14

16

I Rest InO

Immediately after fault inception (A) the fault currents increase severely thus producing a high restraint quantity. At the instant of Ct saturation (B) a differential quantity is produced and the restraint quantity is reduced. In consequence, the operating point IDiff/IRest may move into the tripping area (C). In contrast, the operating point moves immediately along the fault characteristic (D) when an internal fault occurs.

When an external fault is detected, the differential stage for this phase is blocked by an adjustable no. of periods. (for 7UT613/63x now also cross block is possible) Power Automation

34

Power Transmission and Distribution

Power Automation

Tripping Characteristic of 2) - Demonstration of add-on stabilization

(2

Progress. It‘s that simple.

Block

45 °

Trip

add-on stabilisati on

Power Automation

35

Power Transmission and Distribution

Tripping Characteristic - Motor Start Power Automation Progress. It‘s that simple.

Typical for motor start is the starting current and the superimposed dc component with a large time constant. The two Ct-sets may transform this dc component differently. The result is a differential current and the risk of an over-function is given. Detection of motor starting: Increases the pick-up values for a settable time Tripping Characteristic 7UT6 for Motor start

I Diff InO 1231 Idiff>>

Criterion: Supervision of restraint current

7 Start-up characteristic 6 5

IRest > I-Restr. Startup (until 2 I/InO)

4

than the Start-Factor (max. 2) is active for the time:

T Start Max (Duration of dynamical increasing of pickup)

Steady-state characteristic

Trip

45°

Increase of pickup

3 2 Block 1 1221 Idiff>

0

0

2

4

6

8

10

12

14

16

Power Automation

I Rest InO 36

Power Transmission and Distribution

Tripping Characteristic DC offset: Increasing of the Characteristic Power Automation Progress. It‘s that simple. increased characteristic (factor 2)

0.24

0.36 Steady state characteristic

0.12 0.18 Minimum setting Add-on stabilization

Setting Add-on stabilization: 5

7UT613/63x only Power Automation

37

Power Transmission and Distribution

Inrush, cross block, over excitation [V/Hz] 2)

(1 of

filter window 1 cycle

Power Automation Progress. It‘s that simple. iRUSH = iDiff

Cross-block = No (phase separate blocking)

Inrush current in one phase

1P

I 2har I Diff

2P

IDiff, L1 > trip blocking

L2-block

IDiff, L2 > trip blocking

L3-block

IDiff, L3 > trip blocking

3P t

Cross-block = Yes (blocking of all phases)

block Setting value

15 %

L1-block

L1-block L2-block

OR ≥1

IDiff > trip blocking for an adjustable time

L3-block

no block 0

0

t

recognise inrush condition by evaluating the ratio 2nd harmonic I2har to basic wave IDiff.

Time limit for cross-block. Reliable reaction to the inrush condition with cross-block. Trip of a short circuit after the set time delay. recognise over excitation [V/Hz] by evaluating the ratio 3rd or 5th harmonic to basic wave Power Automation

38

Power Transmission and Distribution

Inrush, cross block, over excitation [V/Hz] (2 of 2) Demo: Inrush followed by an internal Fault L1-E Power Automation Progress. It‘s that simple.

Internal fault

IDiff>>

Inrush

IDiff>

Add-on stabilizati on

3 cycles

Power Automation

39

Power Transmission and Distribution

Low impedance Restricted Earth Fault (REF) 2)

(1 of

Power Automation Progress. It‘s that simple.

The REF measures the Neutral current of the object ( ISP = 3I0’ ) and, depending on the angle (∆φ) between 3I0’ and the also measured sum of the phase currents ( 3I0’’ = IL1 + IL2 + IL3 ), decides for internal or external fault. The sensitivity of the REF is almost independent from the load of the object. (The sensitivity of the “Differential Function” especially for high ohm faults will be reduced by the load due to the slope of its “Tripping Characteristic” ).

The REF can be stetted to 0.1 I/INO (min. 0.05) and is therefore more sensitive as the “Differential Protection” (even without load).

Power Automation

40

Power Transmission and Distribution

Low impedance Restricted Earth Fault (REF) Power Automation Progress. It‘s that simple.

Tripping Characteristic REF

IREF> = Setting value (Trip Threshold) IRest = Restraint current IREF = │3I0’│

I REF I REF

Char. for ∆φ= 180°

4

1) for basic Trip-Area (0° ≤ ∆φ ≤ 90°): IREF = │3I0’│ and must be ≥ IREF>

Tripping 3

Characteristic_1): IREF / IREF> = 1 (no restraining current IRest effective)

2

2) for extended Trip-Area (90° ≤ ∆φ ≤ 180°):

1

Blocking

Characteristic_2): IREF = IREF> + k·IRest where IRest = (│3I0’-3I0’’│-│3I0’+3I0’’│) IRest includes the direction

(2 of 2)

-0.3

-0.2

-0.1

0.0

180° ≥ ∆φ > 90° extended Trip-Area

+0.1

+0.2

+0.3

3I '0' 3I '0

90° ≥ ∆φ ≥ 0° basic Trip-Area

calculation of the basic wave and the complex vectors of I0' and I0" evaluation of the modulus and angle between I0' and I0" sensitive fault detection starting with 5% transformer nominal current Power Automation

41

Power Transmission and Distribution

CT Requirements Power Automation Progress. It‘s that simple.

(1 of 3)

Request: k ALF

k ALF_N

R ct R ct

Rb R 'b

4

k ALF

k ALF_N

R ct R ct

Rb R 'b

5

IP I NCtPrim IP I NCtPrim

for : TP 100ms for : TP

where: kALF_N = rated Accuracy Limiting Factor Rct = secondary winding resistance Rb = rated resistive burden IP = max. primary symmetrical short circuit current Example: (TP ≤ 100ms)

100ms

kALF = actual Accuracy Limiting Factor R’b = actual resistive burden TP = Primary (Net-) Time constant

Explanation: 5P20:  kALF_N = 20

110 kV 7UT6 200/1A 5P20,15VA Rct = 1Ω

80m , 2.5 mm2

Wind.1 0.1 Ω

38.1 MVA 110/11 kV uk = 10% 2000/1A 10P10, 10VA Rct = 2Ω

11 kV

50m , 4 mm2

Wind.2 0.1 Ω

Power Automation

42

Power Transmission and Distribution

CT Requirements of 3) Power Automation

(2 Side 2 (LV):

Side 1 (HV):

Progress. It‘s that simple.

Nominal transformer current:

SN 3 U N1

InO1

38100kVA 3 110kV

Nominal transformer current:

Maximum through flowing current:

c InO1 100% uk

I P_1

R 'b

k ALF

Sb I

2 NCtS

2 l ρ q

20

15VA 1A 2

1.1 200A 100% 10%

2200A

15Ω

160m 0.0175 2.5mm

Ωmm 2 m 2

0.1Ω 1.22Ω

1Ω 15Ω 144 1Ω 1.22Ω

k ALF 144

4

IP I NCT prim

4

2200A 200A

c InO 2 100% uk

I P_2

2000A

R 'b

Sb I

2 NCtS

2 l ρ q

k ALF 10 44

OK!

1.1 2000A 100% 10%

22000A

where: c = factor for max. possible over voltage

Rb

R Relay

38100kVA 3 11kV

Maximum through flowing current:

where: c = factor for max. possible over voltage

Rb

SN 3 U N2

InO 2

200A

k ALF

10VA 1A 2

10Ω 100m 0.0175

R Relay

2Ω 10Ω 2Ω 0.54Ω

47.2 4

IP I NCT prim

Ωmm 2 m

4mm 2

0.1Ω

0.54Ω

47.2 4

22000A 2000A

44

OK!

Power Automation

43

Power Transmission and Distribution

CT Requirements of 3) Power Automation Progress. It‘s that simple.

(3

5P20, 200/1A, 15VA, Rct = 1Ω, R’b = 1.22Ω, 11·I/INCT ; TP = 100ms

10P10, 2000/1A, 10VA, Rct = 2Ω, R’b = 0.54Ω, 11·I/INCT ; TP = 100ms

Power Automation

44

Power Transmission and Distribution

Power Automation Progress. It‘s that simple.

Commissioning and operating aids 4) WEB-Technology

(1 of

Access to the relay with a WEB Monitor Help system in INTRANET / INTERNET http://www.siprotec.com

1. Serial connection Direct or via modem with a standard DIAL-UP Network

The homepage of the relay is:http://141.141.255.160 IP-address is set with DIGSI 4 on front- or rear service port

WEB server in the relays firmware Server sends it’s HTML-pages and JAVA-code to the WEB Monitor after a DIAL-UP connection

2. HTML page view in a WEB Monitor with the IP-address of the relay http://141.141.255.160 Power Automation

45

Power Transmission and Distribution

Commissioning and operating aids 4)

(2 of

Power Automation Progress. It‘s that simple.

Transformer YNd11d11, 110/11/11kV, 38.1MVA, IL2S2 wrong polarity Power Automation

46

Power Transmission and Distribution

Commissioning and operating aids 4)

(3 of

Power Automation Progress. It‘s that simple.

Transformer YNd11d11, 110/11/11kV, 38.1MVA, IL2S2 wrong polarity Power Automation

47

Power Transmission and Distribution

Commissioning and operating aids 4)

(4 of

Power Automation Progress. It‘s that simple.

Power Automation

48

Power Transmission and Distribution

Benefits for the Customer Power Automation Progress. It‘s that simple.

Protection relay with flexible adaptation to the transformer/generator/motor or short line. Programming of the device data in the relay. Reduced amount of wiring by direct connection to the main Ct’s. No matching transformers and therefore no wiring errors. Zero sequence current can be measured (in the 7UT6). Sensitivity for single-pole faults in the transformer increased by 33% .

Flexible adaptation of the tripping characteristic to various main Ct’s, tapped transformers. Exact discrimination between the short circuit condition and the inrush condition by on-line analysis of the harmonics. Fast tripping for high-current faults. Ct saturation detector for external faults. Thermal monitoring of one transformer winding (including RTD meas.)

Back-up DMTL/IDMTL with reverse blocking for one winding. Sensitive short circuit protection for faults winding against earth. External Trip functions Various commissioning aids. Common DIGSI 4 software Power Automation

49

Power Transmission and Distribution

Comparison of functions/settings between 7UT51- and 7UT6 relays 7UT51

7UT612

7UT613

7UT633

7UT635

Tripping Characteristic: Base point for slope 1 settable

---

X

X

X

X

Tripping Characteristic: Increasing of characteristic at start

---

X

X

X

X

Tripping Characteristic: minimum setting for add-on stabilization I/InO

5

3

3

3

3

Tripping Characteristic: cross block for add-on stabilization

---

---

X

X

X

Tripping Characteristic: slope of add-on stabilization / slope 1

½

1

1

1

1

Tripping Characteristic: Increasing of characteristic due to DC offset in IDiff

---

---

X

X

X

Transformer inrush: Default setting for cross block 2. harmonic [cycles]

0

3

3

3

3

Transformer inrush: Default setting for 5. harmonic [%]

80

30

30

30

30

Negative sequence current protection

---

X

X

X

X

Over excitation protection [V/Hz]

---

---

X

X

---

Overload protection IEC 60354 (hot spot)

---

X

X

X

X

Single phase busbar differential

---

X

X

X

X

High impedance Restricted Earth Fault

---

X

X

X

X

Voltage measurements

---

---

X

X

---

Temperature monitoring (via Thermo-box / RS 485)

---

X

X

X

X

All functions can be enabled at the same time

---

X

X

X

X

WEB Toll (commissioning aid)

---

X

X

X

X

Power Automation Progress. It‘s that simple.

Power Automation

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