Page 10 - Current & voltage sensors catalog

Three technologies for measuring current

3. Open loop
1
Hall effect technology

Principle
ABB current sensors based on open loop Hall effect technology are also electronic Sensor Power supply
transformers. They allow for the measurement of direct, alternating and impulse I P
currents, with galvanic insulation between the primary and secondary circuits. + V A + V A
The primary current I P flowing across the sensor creates a primary magnetic flux. R M
V S
0V
The magnetic circuit channels this magnetic flux. The Hall probe placed in the air gap
V M
of the magnetic circuit provides a voltage V H proportional to this flux, which is itself 0V
proportional to the current I P to be measured. _ V A _ V A G0212DG
The electronic circuit amplifies this Hall voltage (V H) allowing it to be directly exploited
by the operator as a secondary output voltage V S. The secondary output voltage V S is
The current sensor measures instantaneous values. therefore directly proportional to the
primary current. It is an exact replica
of the primary current, generally with a
value of 4 V for a nominal current I PN.

Advantages Applications
The main advantages of this open loop – Good accuracy over a medium frequency Industry
Hall effect technology are as follows: range (from direct to several tens of kHz). Variable speed drives, backups ("UPS"),
– Galvanic insulation between the – High reliability. active harmonic filters, battery chargers,
primary and secondary circuits. – Low power consumption. conveyers, lifts, cranes, solar inverter, etc.
– Measurement of all waveforms is – Reduced weight and volume.
possible: direct current, alternating – Excellent Performance/Cost ratio.
current, impulse, etc.

8 | ABB