Sensor presentation Product Scope A Sensor is a device intended to - - PDF document

1/23/2003

Sensor presentation

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.

Sensors vs. Instrument Transformers

Trends in electrical engineering

. . . but not in transformers!

Size Performance Standardisation

Sensors vs. Instrument Transformers

Reason: The properties of material used Saturation Unlinear range Linear range Unlinear range Remedy: Absence of iron

Why did ABB choose Rogowski coil

IEC-requirements Cost effective Low life cycle cost Size

Rogowski Rogowski coil coil

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

Why did ABB choose voltage dividers

IEC-requirements Cost effective Safe Low life cycle cost Size

Capacitive voltage divider Capacitive voltage divider Resistive voltage divider Resistive voltage divider

Voltage divider

Resistive divider

Matched resistor pair

1:10 000 divider ratio

Today accuracy up to class 1

Capacitive divider

Zc = 1/ωC

1:10 000 divider ratio

Accuracy up to class 3 Small size ideal for bushings

IEC 60044-7

Sensors vs. Instrument Transformers

Rated primary current (CT) Ipr = 240 A Ip (log)

ε

Sensors vs. Instrument Transformers

Rated primary current range (sensor) Ipr = 80 A....240 A.........…1250 A Ip (log)

ε

Sensors vs. Instrument Transformers

Accuracy limit factor (Kalf) Ipr Ip (log)

εc

Protection class 10P CT CS

Sensors vs. Instrument Transformers

Voltage error

• 8
• 6
• 4
• 2

2 4 6 8 50 100 150 200 250 300 U/Un % %

Error limit, class 3P Typical error, voltage transformer

Linearity

Typical error, voltage sensor

Sensors vs. Instrument Transformers

Low power Low signal High power Transmitted signal level 1,2 - 110 V, 25 VA

At free potential, must be earthed Secondary losses = I2R

12 - 1100 mV, 80 mVA

Always earthed in the sensor Secondary losses negligible

0,25 - 100 A, 5 VA

At free potential, must be earthed Secondary losses = I2R

7,5 - 3000 mV, 6 mVA

At free potential Secondary losses negligible

Voltage transformer (ku=1,9) Voltage sensor Current transformer (Kalf =20) Current sensor

SAFE

Sensors vs. Instrument Transformers

Short-circuited secondary

Voltage transformer Voltage sensor

Isc

Isc/Acu = 160 A/mm2 Temp. 500 °C Explosion within 30 s Isc = Inormal

Isc

250 MΩ 25 kΩ

Current transformer Current sensor

Sensors vs. Instrument Transformers

Uopen Isc

0 - 10 kV Isc/Acu = 40 mA/mm2

Open secondary

Sensors vs. Instrument Transformers

Frequency response

F/Hz

10 10 1000 10 000

VT CT

εrel

CS VS (Res.) VS (Cap.)

Sensors vs. Instrument Transformers

Secondary wiring

• Instr. transf.

Terminal blocks IED

Wiring and screw connections Testing of connections

Sensor IED

Integrated cable and connector

Secondary cabling of sensors

Sensor IED

S1 S2

Combi Sensor Voltage transformer Current transformer

Sensors vs. Instrument Transformers

Small size of active parts Only one core Small size of active parts Only one core

Compactness

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

Sensors

1/5A / 100/110 V

CT / VT

Excluded No Yes Yes (VT) No No Destructive (VT) Destructive (CT) 40-60 kg (CT + VT) No

Standards for Sensors

Sensors from ABB are designed, manufactured and tested according 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: Electronic current transformers Combi Sensors: IEC 60044-3 (1980-01) Instrument transformers – Part 3: Combined transformers

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

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

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 adapter 640 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

Sensor concept

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

Sensors in use around the world

Arguments for Sensors Safety Short delivery time Smart integration