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Trench Group Special Reactors

Trench is a supplier of specialized electrical products and a recognized world leader in the design and manufacture of dry type air-core reactors for all utility and industrial applications. The reactor range goes from small kvar to large power reactors for variuos applications and includes also special reactors for unique challenges in industrial and utility projects.

For more than 60 years Trench develops together with its customers special reactors for different and unique applications such as reactor for test labs used in the electrochemical industry and the transportation industry on ships and in railway networks. The unique experience combined with an extensive investment into engineering, manufacturing and testing capabilties makes Trench the prefered partner for any special application of reactors.



Tony Trench invented the world’s first dry-type air-core reactor

encapsulated in epoxy-impregnated resin – a design that set the standard for all modern coils worldwide

Main features

  • Reactive power approx. 250 kVAr up to 30 MVAr (50 Hz equivalent)
  • System voltage up to ~24 kV
  • System DC or AC (single- or 3-phase)
  • Installation: indoors or cubicle mounted
  • Cooling: WF, AN, AF, AV (air-ventilated)
  • Core design: dry type, core or shell-type
  • Tailor made based on customer‘s specification
  • Conductor material: Aluminium or copper
  • For WF cooling with integrated hollow conductors

A vaste experience in developping special reactors in air-core technolgoy makes Trench the preferred partner for any special reactor application.

Key Applications

  • Industrial Power Conversion:
    – Large variable-speed drives (e.g. for steel industry, oil pumps and compressors for oil and gas transportation)
    – Electrochemical industry (e.g. galvanotechnics)
  • Naval and Railway Sector
    – Large variable-speed drives for ships
    – Stationary power conversion for railway systems
  • Power System (Energy-)Sector
    – Current limiting and harmonic filtering
    – Di/Dt limiting saturable reactors
  • UPS (uninterruptible power supply)-Systems
    – Especially HV UPS-Systems

Test lab reactors

Test lab reactors are installed in high-voltage and high-power test laboratories. Typical applications include current-limiting, synthetic testing of circuit-breaker, inductive energy storage and artificial lines

International customers count on Trench’s experience when equipping high voltage test laboratories with reactors. The history goes back to the 1960s when Trench supplyed high current and high voltage test reactors for international test laboratories like KEMA in Arnheim/The Netherlands.

Neutral earthing reactors

Neutral earthing reactors limit the line-to-earth fault to specified levels. Specifications should include unbalanced condition, continuous current duration and short-circuit current duration

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