Rectifier Systems

For Industrial Application


PT Anugerah Indah Perkasa is here to provide a solution for your rectifier needs in Indonesia with the support of  Friem with their more than 60 years of experience, FRIEM is World Leader in the design and manufacturing of Special Rectifiers and Power Converters for Industrial Applications rated up to 200 kA and 2000 V.
With continuous investments in research and development, FRIEM is capable to provide a complete Conversion System tailored on Customers’ requests, suited with each type of semiconductor (diodes, thyristors or IGBTs) and with the most advanced Digital Regulations and electronics.

Friem Transformer Premagnetization

This unit is specifically designed, case by case, to limit the inrush current during the start-up of the main rectifier transformer by pre-magnetizing the core from an independent power supply.

During the uncontrolled energisation of transformer,
the large transient current due to flux saturation in
the core, which is called inrush current, can reduce the
transformer’s life due to the high mechanical stresses
involved, and can also lead to the unexpected operation
of protective relays and power quality reduction.
This transient current affects costing time and money as
the engineers have to examine closely the transformer
and the protective system, to check for faults.
The large transient current also causes serious
electromagnetic stress impact and shortens the life of
transformer. The over-voltage resulting from the inrush
current may cause damages to other power apparatus.
FRIEM dedicated engineering to provide a solution to
avoid magnetization peak current during start-up of
main rectifier transformer: the Premag unit.
Concept of premagnetization is to pre-magnetize the
transformer core from an independent source in order
not to have a huge voltage variation at the insertion,
thus limiting the inrush current.
The Premag has a specific design for each transformer
or set of transformers.

Technical Features
• Premag is able to operate with transformer
connected to HV or MV networks and at 50Hz or 60Hz
• Premag is suitable for Vacuum or Gas insulated
Circuit Breakers
• Premag is able to operate with OLTC equipped
Transformers as well with OCTC equipped
• The premagnetizing cycle will be managed by
the PLC automatically at the act of commanding
the closure of the MV circuit breaker (operation
of the OPEN/CLOSE key on the rectifier control
• At the act of commanding the closure of the
MV breaker the PLC will receive the request for
closing, will check for all the interlocks and then
implement the premagnetization cycle
• Premag intervention can be inhibited, in case
of need, using a dedicated function on the HMI

+62 21 2252 3689

+62 21 2252 3690

Customer Service

Email :

Green Lake City, Rukan Sentra Niaga Blok G No. 10, Jakarta 11750 – Indonesia

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Please contact us for consultation and quotation