Page 11 - Current & voltage sensors catalog

Two technologies for measuring voltage

1. Electronic technology
1

Principle
ABB voltage sensors based on electronic technology only use electronic components. Sensor Power supply
In contrast to closed or open loop Hall effect technology, no magnetic circuits or Hall HT +
+
+ V A
effect probes are used in the sensor.
This allows for the measurement of direct or alternating voltages with electrical
M I s R M
insulation between the primary and secondary circuits. Up 0 V
V M
The primary voltage to be measured is applied directly to the sensor terminals: HT+
(positive high voltage) and HT– (negative high voltage or earth). This voltage is passed
– – V A
through an insulating amplifier and is then converted to a secondary output current I S. HT - G155DG
This secondary current Is is electrically insulated from the primary voltage to which it
is exactly proportional. In the same way as for current sen-
The voltage sensor measures instantaneous values. sors, this secondary current I S can
be then passed through a measuring
resistance R M. The measuring voltage
V M at the terminals of this measuring
resistance R M is therefore also exactly
proportional to the primary voltage U P.
The electrical supply to the sensor is
also insulated from the primary voltage.

Advantages Applications
The main advantages of this fully electronic – Excellent immunity to electromagnetic Railway
technology are as follows: fields. Main converters, auxiliary converters
– Electrical insulation between the – Excellent accuracy. (lighting, air conditioning), battery char-
primary and secondary circuits. – High dynamic performance. gers, choppers, substations, mining, etc.
1SBC140076S0201
– Measurement of all waveforms is – Excellent reliability.
possible: direct voltage, alternating
voltage, impulse, etc.

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