Roebel bar windings

For generators from about 30 MVA onwards and for special motors, so-called Roebel bar windings are used. These bars, consisting of a large number of individual braided strands, create an improved current distribution within the slot as compared to the skin effect

Additional info

The manufacture of special winding bars requires a special machine park, such as:

  • Insulation cutting and stripping machines, combined with cropping tools for bars up to 10 m in length
  • Hot coil presses for preforming and resin-rich pressing of bars

The finished, pre-cured bars are bent into the required involute shape using a bending robot. Following this procedure, the bars receive soldering lugs for the installation on site.

Our production line is supplemented by a taping robot for the application of the main insulation.

The PARTZSCH Group is able to produce straight bars up to a total length of 10 m and
a rated voltage not exceeding 21 kV. In case of the VPI design, the maximum laminated core length is 8.0 m.

Apart from the manufacturing of individual bars, our production range also includes complete Roebel-bar windings.


Technical parameters
  • Minimum cross section of the insulated conductor: 4 x 1 mm
  • Maximum cross section of the insulated conductor: 16 x 4.5 mm
  • Number of conductors per half-bar: 80
  • Maximum conductor length of cutting: 10,100 mm ± 2 mm
  • Maximum number of crop/stamp locations: 180°; 360°; 540° Special Roebel procedures possible
InsulationProductVoltageTemperature index (TI)Comments
Resin-Rich complete windings ≤13,8 / ≤16 kV 155 (F) insulation tapes, hot-pressed
  diamond coils ≤13,8 / ≤16 kV 155 (F)  
  Roebel bars ≤13,8 / ≤16 / 21 kV 155 (F)  
VPI-Polyester complete windings ≤13,8 / ≤16 kV 180 (F) polyesterimide resin (UP), vacuum-pressure method
VPI-Epoxid complete windings ≤13,8 / ≤16 kV 155 (F) epoxy resin (anhydride)
  Roebel bars ≤13,8 / ≤16 / 21 kV 155 (F) vacuum-pressure method