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High Power Transformer Rectifier Systems for Graphite Applications

Added Benefits of Power Electronic Systems Supplied by Neeltran – Robust and Reliable Power to run your 24/7 processes.

At Neeltran, we are uniquely positioned as one of the few companies in the world that designs and manufactures its own rectifier-transformers and rectifiers. This capability allows for combined Full Current and Full Voltage factory testing of the transformer and rectifier in their actual configuration prior to shipment.  Neeltran can build a stationary unit or a unit that moves on a rail car.

An experienced client requires combined testing to eliminate integration problems at the site and to assure the shortest commissioning time, resulting in significant cost savings and the highest quality units.

Neeltran possesses multi-industry, engineering, and manufacturing experience that helps us to be flexible and design products that meet your specific technical and safety requirements.


  • Diode units available
  • Latest safety features
  • Design to all types of environments and contamination
  • Remote monitoring via PLC modem
  • State-of-the-art Neeltran fast response control boards with Microprocessor based controller available
  • All types of PLC's available for easy interface to customer systems
  • Semiconductor Plasma Arc protection available
  • On Load Tap Changer available, in all cases including NLTC tap changer will have its own seaperate oil supply
  • EMF, RFI and Magnetic studies available
  • FEM analysis available
  • Harmonic studies available
  • E House style available
  • Based on specifications we can conform to ANSI, IEC, IEEE,NEMA, CSA, BS, AS, JS, CE etc...
  • Conservative Transformer design (dry, water or oil type)
  • Conservative selection and specially developed water cooled thrysitor system provides unmatched reliability
  • Design to seismic zone
  • Altitude Walk-in metal or aluminum enclosures available with all types of IP or Nema
  • Ratings High Efficiency units with low operating temperatures
  • N-1 SCR's with no need for matched devices
  • Modular and scalable design
  • Modernization and component reduction improvements leads to best MBTF Multi-pulse configurations available
  • Superior short circuit withstand Design to local environment, altitude and cooling conditions with all cooling system types available
  • Mutliple DC current measurement types available
General Specifications Data Sheet PDF Data Sheet PDF (Spanish)
Three-phase supply voltage main by customer V up to 69000
Maximum power kVA up to 70000
Three phase voltage on the secondary V up to 500
Frequency Hz 50-60
NLTC or OLTC No Load and On Load Tap Changers
DC Current A up to 200000
DC Voltage V up to 400
Rectifier Connection ANSI - IEC Bridge or Star
Pulses 6 / 12 / 18 / 24 / 36 and more
Control card type Digital or Analog, hard wired or OPTO
Accuracy of the constant current control system ±0.5%
Transformer Cooling Oil to Water / Oil to Air
Transformer Manufacturer Neeltran
Transformer Oil Type Mineral / FR3 / Silicon
Metering Shunt / LEM / Primary CT
PLC Allen Bradley or Siemens, others available. Dial in Modem or Cellular modem for diagnostics
Rectifier Cooling Deionized Water to Water / Deionized Water to Air
Rectifier Enclosure Type Compact / Semi-walk in / Walk in
Rectifier Manufacturer Neeltran
Rectifier power section material Aluminum or Copper
Rectifying elements Thyristors / Diodes
Redundancy N+X
Line Up Testing Available Combined Test at Neeltran Factory