Field coil windings

The field coil winding is, among others, a component of synchronous machines and is typically found on the rotor. The coils are directly wound or plugged onto the pole.

They are available in various designs (made of insulated flat or round wire, edgewise wound from bare copper or soldered from individual copper parts). The individual coils are connected to allow the magnetisation direction change from pole to pole.

Technical parameters

Structure of pole wheels made of separately wound field coils:

  • Total weight up to 32 t
  • Feasibility of other dimensions will be checked

upon request Round-wire field coils:

  • Up to 50 kg net weight
  • Up to 1 m in length
  • Feasibility of other dimensions will be checked

upon request Field coils made of insulated flat wire:

  • Material strand insulation (enamel, enamelled wire insulated with glass yarn, Daglas)
  • Maximum weight: 5 t
  • Maximum length: 4 m
  • Maximum width: 1 m
  • Wire bent over the high edge starting at wire thicknesses of 2 mm with a width of 10 mm
  • Feasibility of other dimensions will be checked

upon request Field coils made of water-jet cut copper parts:

  • Copper parts can be cut using our water-jet cutting system

For synchronous generators in four- and multi-pole design with rated voltages exceeding 15 MVA, poles are manufactured from profiled copper stripes. Each winding consists of four individual copper metal strips soldered or welded together to form a continuous, flat coil winding. Here, the processing and treatment of joints is of particular importance, as these must not exhibit thickening.

Using great pressure and current-generated heat, the coils are then cured to size. A subsequent mechanical processing is performed in the next step in order to place the cutouts for the clamping elements, fastenings and stabilisers of the field coils.

The pole cover plates are screwed onto the rotor shaft. This is performed using a hydraulic wrench with a maximum tightening torque of 44,000 Nm.

Machinery field coil windings

Pole welding machine
  • Minimum coil internal dimension, width: 140 mm
  • Minimum coil internal dimension, length: 1,100 mm
  • Maximum coil external dimension, width: 1,000 mm
  • Maximum coil external dimension, length: 3,000 mm
  • Maximum total height of coil: 320 mm
  • Maximum weight of coil: 1,200 kg
  • Maximum conductor width: 105 mm
  • Conductor height 2 to 7 mm (larger conductor heights must be checked for feasibility using soldering sample)
  • Feasibility of other dimensions will be checked upon request