Subject:  Re (H,T) Transients, explanation
Date:     Wed, 30 Jul 1997 084045 -0500 (CDT)
From:     Rocoil_T@sesame.demon.co.uk (John Clews)
To:       Multiple recipients of list <emf-l@mail.llion.org>
--------------------------------------------------

In message <2.2.32.19970730092100.007662d0@mail.umt.se>
emf-l@mail.llion.org writes:

> At 14:53 1997-07-29 -0500, Drasko wrote:
> >issue, so I hope somebody from the List would respond to this, explaining
> >the TRANSIENTS issue in several sentences.
>
> A transient is a short and fast transition from one state to another, and
often
> back again. Most transients on our power system is due to switching on or
off
> various power loads (devices)... they may carry enough energy to make an
inpact on
> living things, we don't now yet.
>
> The Hydro-Quebec study indicated transients as an important factor to look
at,
> but their way of measuring them has been critized. Exactly how do one
proceed
> to measure transients? No easy task at all.

John Clews adds:

Rogowski Coil Current Transducers (a toroidal winding on a
non-magnetic core) can be used for the measurement of transients in
alternating currents. They can be used in similar circumstances to
current transformers but for many applications they have considerable
advantages. The transducer does not measure direct currents but,
unlike a current transformer, it can make accurate measurements even
when a large dc component is present because there is no iron core to
saturate.

Rogowski Coil Transducers have many advantages over the conventional
current transformer, including:

Wide Dynamic Range (currents from milliamps to hundreds of kiloamps).
Wide Bandwidth - typically 0.1 Hz to over 100 kHz.
Low Phase Error - less than 0.1 in the mid-frequency range.
No danger from open-circuited secondaries.
Cannot be damaged by large overloads.

For further information, send an email to

        Rocoil@sesame.demon.co.uk

with this message:

        SEND ROCOIL.INF

John Clews

--
Rocoil Ltd: David Ward (Technical Director); John Clews (Information
Officer)
   5 Almsford Avenue, Harrogate, North Yorkshire, HG2 8HD, United Kingdom
Rocoil@compuserve.com;  Rocoil@sesame.demon.co.uk;  Tel/Fax: +44 1423 871
792


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