Professional paper

https://doi.org/10.19279/TVZ.PD.2018-6-1-05

TRANSFORMER INRUSH CURRENT

Ivor Marković ; Zagreb, University of Applied Sciences
Tomislav Đuran ; Zagreb University of Applied Sciences, Zagreb, Croatia
Zvonimir Meštrović ; VERTIV CROATIA d.o.o., projektant, Zagreb, Hrvatska

Abstract

This paper describes the phenomena and problems
that arise when connecting the transformer
to the power grid. When connecting the transformer
to the grid (even in idle mode i.e.no load
mode), high transient current flows occur, which
can have various negative consequences. The
transient inrush current can be up to tens of
times higher than the nominal current. As this is
a short-term occurrence, there is usually no permanent
damage to the transformer itself, but protection
of the transformer can be activated, which
makes it difficult to switch on and results in losses.
Also, 3 cases of inrush current were observed:
a) connection of transformer to the grid ina n instant
when voltage is equal to zero and with remanent
magnetic flux
b) connection of transformer to the grid in an instant
when voltage is equal to maximal value and
with remanent magnetic flux
c) connection of transformer to the grid in an instant
when voltage is equal to maximal value and
without remanent magnetic flux
In the end, the usual other industrial methods
used in connection with the grid are briefly
mentioned.

Keywords

transformer; inrush current; lamination demagnetization; magnetic flux

Hrčak ID:

203038

URI

https://hrcak.srce.hr/203038

Publication date:

26.3.2018.

Article data in other languages: croatian

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