07-08-2012, 12:48 PM
CTDim
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The challenge
The development of the digital protection technology
and the introduction of gas insulated switchgear
(GIS) have lead to a paradigm change in current
transformer dimensioning. As a result, the accuracy
limiting factor of the CT plays an important role,
rather than the nominal burden of the CT. Unfortunately
sometimes specifications regarding CTs have
not been changed and are now in contradiction with
the limited space reserved for CTs in GIS substations.
Therefore, the optimization of CTs regarding both
technical requirements of modern digital relays and
economic aspects is becoming more and more important.
Our solution
CTDim makes CT dimensioning more efficient. It
saves engineering and production costs by optimizing
the current transformer data.
The program CTDim comprises the following features:
• Easy dimensioning of CT electrical data
• Database of specific CT requirements for protection
devices (Siemens and other manufacturers)
• Input of CT data according to the following standards:
IEC class P, PX and TPS, BS and ANSI
Application Examples
In new substations, the process of CT dimensioning
takes place at the beginning of
the project planning for the switchgear. If
the current transformers act as an interface
between primary and secondary system, a
lot of clarification work has to be done at
this stage of the project planning. The function
of CT, which is specified according to
the secondary equipment it will be connected
to, has a straightforward influence
on its size and in consequence on the sizing
of the whole switchgear.