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 outdoor switches for measuring, protection and indication.

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

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

Rogowski coil First published in1912 by Rogowski and Steinhous Passive element Uniformly wound coil with non-magnetic core Output signal is proportional to the derivate of primary current IEC 60044-8 Distribute the coil Note the missing of turn wire to eliminate disturbance

Requirements for a Current Sensor IEC-requirements Cost effective Low LCA Size Rogowski 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

Sensors vs. Instrument Transformers Rated primary current (CT)  Ip (log) Ipr=80 A

Sensors vs. Instrument Transformers Rated primary current range (sensor)  Ip (log) Ipr = 40 A.......80 A................160 A

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

Voltage Divider IEC 60044-7 Resistive divider Matched resistor pair 1:10 000 divider ratio Accuracy up to class 0.2 Capacitive divider Zc = 1/C 1:10 000 divider ratio Accuracy up to class 3 Small size ideal for bushings IEC 60044-7 Cast in type, gas insulated 10 meters due to capasitances -> phase error

Requirements of a Voltage Sensor IEC-requirements Cost effective Safe Low LCA Size Resistive Voltage divider IEC-60044-7 = 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 Capacitive Voltage divider

Sensors vs. Instrument Transformers Linearity Typical error, sensor

Sensors vs. Instrument Transformers Transmitted signal level Voltage transformer (ku=1,9) Voltage sensor 1,2 - 110 V, 25 VA 12 - 1100 mV, 80 mVA At free potential, must be earthed Always earthed in the sensor Secondary losses = I2R Secondary losses negligible Current transformer (Kalf =20) Current sensor 0,25 - 100 A, 5 VA 7,5 - 3000 mV, 6 mVA At free potential, must be earthed At free potential

Sensors vs. Instrument Transformers Short-circuited secondary (VT) Voltage transformer Voltage sensor 250 M Isc Isc 25 k Isc/Acu = 160 A/mm2 Temp. 500 C Explosion within 30 s Isc = Inormal

Sensors vs. Instrument Transformers Open secondary (CT) Current transformer Current sensor Isc Uopen 0 - 10 kV Isc/Acu = 40 mA/mm2

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

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

Sensors Secondary wiring II, Shielding Sensor IED S1 S2

Sensors vs. Instrument Transformers Compactness Current transformers Combisensor Voltage transformer Size of active parts Number of cores

Sensor Technology - CT/VT vs. Sensors

Standards for Sensors Sensors from ABB are designed, manufactured and tested according to international standards when applicable. n Voltage sensors : IEC 60044-7 (1999-12) n Instrument transformers – n Part 7: Electronic voltage transformers n Current sensors : IEC 60044-8 (2002-07) n Instrument transformers – n Part 8: Electrical current transducers n Combisensors : IEC 60044-3 (1980-01) n Instrument transformers – n Part 3: Combined transformers

Combi Sensor, type KEVCD_ Current and voltage sensors in the same block 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 Sensors

Sensor Concept

Sensors in use around the world In use in 56 countries More than 20 000 sensors in operation

Sensors in use around the world

Sensors Safety Short delivery time Smart integration