Omicron CPC 100 Reference Manual

CPC 100 V1.41
4 - 38
CT Rogowski (Ratio)
Use the CTRogowski test card to measure a Rogowski coil’s ratio by injecting
current up to 800 A from CPC 100 800A AC output or up to 2000 A using the
CP CB2 current booster connected to the "EXT. BOOSTER" output into the
current-carrying conductor, and by measuring the induced voltage at the end of
the Rogowski coil windings.
A Rogowski coil’s induced voltage is proportional to the conductor current
differentiated with respect to time. Therefore, in order to acquire a direct
equivalent of the conductor’s current, the induced voltage needs to be
integrated. In general, a Rogowski coil’s output signal is either lead via an
integrating amplifier or fed into an electronic protection relay with integrator. The
CTRogowski test card integrates the Rogowski coil’s output signal at the
CPC 100 input V2AC.
Disconnect the Rogowski coil’s output signal from the electronic protection relay,
and plug it into CPC 100 V2AC input.
The CTRogowski test card measures the amplitude of the injected current
Iprim and the Rogowski coil’s output voltage Vsec, integrates this signal, and
calculates the secondary current Isec, its phase angle as well as the actual ratio
and the deviation.
Figure 22:
Setup for a CT ratio test
of a Rogowski coil
Please refer to the note below.
electronic
protection
relay with
integrator
(for
example
150mV at
Shielded cable with
twisted wires.
Shield connected
to Rogowski coil.
P1
P2

Omicron CPC 100 Specifications

General

Brand	Omicron
Model	CPC 100
Category	Test Equipment
Language	English