1. Sensor presentation

2. Product Scope
A Sensor is a device intended to transmit a signal corresponding to the primary current or voltage to the secondary equipment.
PowerIT Sensors are typically used in MV switchgears and switches for measuring, protection and indication.

3. Sensors vs. Instrument Transformers
. . . but not in transformers!
Trends in electrical engineering
Size
Performance
Standardisation

4. Sensors vs. Instrument Transformers
Reason: The properties of material used
Saturation
Unlinear range
Linear range
Unlinear range
Remedy: Absence of iron

5. Why did ABB choose Rogowski coil
IEC-requirements
Cost effective
Low life cycle cost
Size
Rogowski coil
What is the requirment -> it should work
New technic -> Better than the old
ABB started to look into new technologies in 1990
IEC: ABB involved in taking up the new standard
Cost Effective:
Standardisation
Cost savings for end customer (user friendly)
reliable
Easy to make/logistics

6. Rogowski coil First published in1912 by Rogowski and Steinhous
Uniformly wound coil with non-magnetic core
Output signal is proportional to the derivate of primary current
IEC
Distribute the coil
Note the missing of turn wire to eliminate disturbance

7. Why did ABB choose voltage dividers
IEC-requirements
Cost effective
Safe
Low life cycle cost
Size
Capacitive voltage divider
IEC = Electronic voltage transformers
Cost effective, if no space is forceen in the switchgear special VT’s must be used
Safe = VT faults very common
Size = can be integrated
Resistive voltage divider

8. Voltage divider Resistive divider Capacitive divider IEC 60044-7
Matched resistor pair
1: divider ratio
Today accuracy up to class 1
Capacitive divider
Zc = 1/C
1: divider ratio
Accuracy up to class 3
Small size ideal for bushings
IEC
Possible to achieve accuracy class 0.2 by using resistive divider technology

9. Sensors vs. Instrument Transformers
Rated primary current (CT) 
Ip (log)
Ipr = 240 A

10. Sensors vs. Instrument Transformers
Rated primary current range (sensor) 
Ip (log)
Ipr = 80 A A …1250 A

11. Sensors vs. Instrument Transformers
Accuracy limit factor (Kalf) c
Protection class 10P CS
Ip (log) CT
Ipr

12. Sensors vs. Instrument Transformers
Linearity
Typical error, voltage sensor

13. Sensors vs. Instrument Transformers
Transmitted signal level
Voltage transformer (ku=1,9)
Voltage sensor
1, V, 25 VA
At free potential, must be earthed
Secondary losses = I2R
mV, 80 mVA
Always earthed in the sensor
Secondary losses negligible
Current transformer (Kalf =20)
Current sensor
0, A, 5 VA
At free potential, must be earthed
Secondary losses = I2R
7, mV, 6 mVA
At free potential
Secondary losses negligible
High power
Low power
Low signal
SAFE

14. Sensors vs. Instrument Transformers
Short-circuited secondary
Voltage transformer
Voltage sensor
250 M
Isc
Isc
25 k
Isc/Acu = 160 A/mm2
Temp C
Explosion within 30 s
Isc = Inormal

15. Sensors vs. Instrument Transformers
Open secondary
Current transformer
Current sensor
Uopen
Isc kV
Isc/Acu = 40 mA/mm2

16. Sensors vs. Instrument Transformers
Frequency response
rel CT
F/Hz 10
100
1000
10 000 VS
(Cap.) VS
(Res.) VT CS

17. Sensors vs. Instrument Transformers
Secondary wiring
Terminal blocks
Instr. transf.
IED
Wiring and screw connections
Testing of connections
Sensor
IED
Integrated cable
and connector

18. Secondary cabling of sensors
IED S1 S2

19. Sensors vs. Instrument Transformers
Compactness
Current transformer
Combi Sensor
Voltage transformer
Small size of active parts
Only one core

20. Sensor Technology - CT/VT vs. Sensors
Signal
1/5A / 100/110 V
150mV / 2V
Secondary cables
Excluded
Incl. and tested
Linearity No
Yes
Saturation
Yes No
Ferroresonance
Yes (VT) No
Temperature coefficient No
Incl. in accuracy
EMC No
Shielded
Short-circuited secondary
Destructive (VT)
Safe
Open secondary
Destructive (CT)
Safe
Weight
40-60 kg (CT + VT)
2-25 kg (Combi)
Standardisation possible No
Yes

21. Standards for Sensors Voltage Sensors: IEC 60044-7 (1999-12)
Sensors from ABB are designed, manufactured and tested
according to international standards when applicable.
Voltage Sensors: IEC ( )
Instrument transformers –
Part 7: Electronic voltage transformers
Current Sensors: IEC ( )
Instrument transformers –
Part 8: Electrical current transducers
Combi Sensors: IEC ( )
Instrument transformers –
Part 3: Combined transformers

22. Sensor, type KEVCD_ Current Sensor or Combi Sensor
Measurement and protection by one sensor
Dimensions and primary connections same as DIN-type CTs (DIN 42600)
12, 17.5, 24 kV, two types:
A. </= 1250 A
B. > 1250 A (max A)
Including coupling electrode for voltage indication

23. Selection Guide for KEVCD type Sensors
Nominal
voltage
Rated current range (first row)
Functions included (second row)
< 1250 A A
I + U + Uind
I + Uind
I + U + Uind
I + Uind
Upto 12 kV
KEVCD 12 AE3
KEVCD 12 AG3
KEVCD 12 BE2
KEVCD 12 BG2
Upto 17.5 kV
KEVCD 17.5 AE3
KEVCD 17.5 AG3
KEVCD 17.5 BE2
KEVCD 17.5 BG2
Upto 24 kV
KEVCD 24 AE3
KEVCD 24 AG3
KEVCD 24 BE2
KEVCD 24 BG2

24. Technical Information in KEVCD Sensor
KEVCD 12 AE3
I-sensor
Ipn: A
Ipr (to be advised), options: 80 A (Ir of switchgear: A)
240 A (Ir of switchgear: A), with adapter
640 A (Ir of switchgear: A), with adapter
Output signal: 150 mV (50 Hz), 180 mV (60 Hz)
Accuracy: Class 1* / 3 (*with correction factor)
U-sensor
Division ratio: /1
Accuracy: Class 1/3P
Ith / Idyn: 40 kA, 3s / 100 kA
Insulation level: 12/28/75 kV
Frequency: 50/60 Hz
With ribs on top
Secondary cable (length to be advised), options: 5 m, 6.5 m or 7.5 m
Primary polarity (to be advised), options: Normal or reversed
Coupling electrode for voltage indication included

25. Sensor concept

26. Sensors in use around the world
In use in 56 countries
More than sensors in operation

27. Sensors in use around the world

28. Arguments for Sensors
Safety
Short delivery time
Smart integration