sensor presentation

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Sensor presentation

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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.

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Sensors vs. Instrument Transformers

Trends in electrical engineering

. . . but not in transformers!

Size

Performance

Standardisation

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Reason: The properties of material used

Saturation

Unlinear range

Linear range

Unlinear range

Remedy: Absence of iron

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Why did ABB choose Rogowski coil

IEC-requirements

Cost effective

Low life cycle cost

Size

Rogowski coilRogowski coil

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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 60044-8

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Why did ABB choose voltage dividers

IEC-requirements

Cost effective

Safe

Low life cycle cost

Size

Capacitive voltage dividerCapacitive voltage divider

Resistive voltage dividerResistive voltage divider

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Voltage divider

Resistive divider Matched resistor pair

1:10 000 divider ratio

Today accuracy up to class 1

Capacitive divider Zc = 1/C

1:10 000 divider ratio

Accuracy up to class 3

Small size ideal for bushings

IEC 60044-7

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Rated primary current (CT)

Ipr = 240 A

Ip (log)

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Rated primary current range (sensor)

Ipr = 80 A....240 A.........…1250 A

Ip (log)

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Accuracy limit factor (Kalf)

Ipr

Ip (log)

c Protection class 10P

CT

CS

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Voltage error

-8

-6

-4

-2

0

2

4

6

8

0 50 100 150 200 250 300

U/Un %

%

Error limit, class 3P

Typical error, voltage transformer

Linearity

Typical error, voltage sensor

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Low powerLow signal

High power

Transmitted signal level

1,2 - 110 V, 25 VAAt free potential, must be earthed

Secondary losses = I2R

12 - 1100 mV, 80 mVAAlways earthed in the sensorSecondary losses negligible

0,25 - 100 A, 5 VAAt free potential, must be earthed

Secondary losses = I2R

7,5 - 3000 mV, 6 mVAAt free potential

Secondary losses negligible

Voltage transformer (ku=1,9) Voltage sensor

Current transformer (Kalf =20) Current sensor

SAFE

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Short-circuited secondary

Voltage transformer Voltage sensor

Isc

Isc/Acu = 160 A/mm2

Temp. 500 C

Explosion within 30 s

Isc = Inormal

Isc

250 M

25 k

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Current transformer Current sensor


Uopen

Isc

0 - 10 kV

Isc/Acu = 40 mA/mm2

Open secondary

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Frequency response

F/Hz10 100

1000 10 000

VT

CTrel

CSVS(Res.)

VS(Cap.)

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Secondary wiring

Instr. transf. Terminal blocks IED

Wiring and screw connectionsTesting of connections

Sensor IED

Integrated cableand connector

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Secondary cabling of sensors

Sensor IED

S1S2

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Combi Sensor

Voltage transformer

Current transformer


Small size of active parts

Only one core

Small size of active parts

Only one core

Compactness

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Sensor Technology - CT/VT vs. Sensors

Signal

Secondary cables Incl. and tested

Linearity Yes

Saturation No

Ferroresonance No

Temperature coefficient Incl. in accuracy

EMC Shielded

Short-circuited secondary Safe

Open secondary Safe

Weight 2-25 kg (Combi)

Standardisation possible Yes

150mV / 2V

Sensors1/5A / 100/110 V

CT / VT

Excluded

No

Yes

Yes (VT)

No

No

Destructive (VT)

Destructive (CT)

40-60 kg (CT + VT)

No

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Standards for Sensors

Sensors from ABB are designed, manufactured and testedaccording to international standards when applicable.

Voltage Sensors: IEC 60044-7 (1999-12)Instrument transformers –Part 7: Electronic voltage transformers

Current Sensors: IEC 60044-8 (2002-07) Instrument transformers –

Part 8: Electrical current transducers

Combi Sensors: IEC 60044-3 (1980-01)Instrument transformers –

Part 3: Combined transformers

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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. 3200 A)

Including coupling electrode for voltage indication

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Selection Guide for KEVCD type Sensors

I + U + Uind

Upto 12 kV

Upto 17.5 kV

I + Uind I + U + Uind I + Uind

Upto 24 kV

KEVCD 12 AE3

KEVCD 17.5 AE3

KEVCD 24 AE3

KEVCD 12 AG3

KEVCD 17.5 AG3

KEVCD 24 AG3

KEVCD 12 BE2

KEVCD 17.5 BE2

KEVCD 24 BE2

KEVCD 12 BG2

KEVCD 17.5 BG2

KEVCD 24 BG2

< 1250 A 1600...3200 A

Rated current range (first row)Functions included (second row)Nominal

voltage

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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

Technical Information in KEVCD Sensor

KEVCD 12 AE3

I-sensor

Ipn: 1250 A

Ipr (to be advised), options: 80 A (Ir of switchgear: 80-160 A)240 A (Ir of switchgear: 160-480 A), with adapter640 A (Ir of switchgear: 480-1250 A), with adapter

Output signal: 150 mV (50 Hz), 180 mV (60 Hz)

Accuracy: Class 1* / 3 (*with correction factor)

U-sensor

Division ratio: 10.000/1 Accuracy: Class 1/3P

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Sensors in use around the world

In use in 56 countries

More than 20 000 sensors in operation

In use in 56 countries

More than 20 000 sensors in operation

sensor presentation

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