Generators

We can apply the full suite of inspections both on-site and in our workshop, allowing us to diagnose your machine’s condition:

• Visual and boroscopic inspections.
• Robotic inspection of the air gap, wedge tapping and EL-CID test.
• Diagnostic tests of the winding (Partial Discharges, tan δ, RSO).
• Corona camera inspection for visualization of discharges.
• High Induction test (loop test) with thermography of the stator lamination.
• NDT (dye penetrant, ultrasonic, magnetic particle).
• Modal Analysis (Bump Test).
• Online measurement system installation and online measurement/monitoring of partial discharges.
• Vibration measurement.
• Shaft voltage and shaft current measurement.
• Hydrogen leakage test.

Should something go wrong, then our experts are ready to troubleshoot and recommend how to remediate the situation as fast and cost effectively as possible.

For almost all sizes up to 1000 MVA and from almost all manufacturers, we can take care of all required work in the chain: dismantling, overhaul, repair, testing, reinstallation, and commissioning.

Our repair capabilities include rotor- and stator rewinding , high speed balancing, stator core renewal, coils- and Roebel-bars manufacture and refurbishment of H2-auxiliary systems.

We try to work as much as possible on site, but if required, we have fully equipped workshops to support more complex projects.

Starting from known weaknesses or damages, we provide FEM modelling of machines and their components. We calculate the strength of the concerned components, provide root cause analysis and engineer modifications to achieve enhanced reliability and durability of your generators. Examples of modifications are:

• Long ring- and short-ring modifications of generator rotor body shrink seats for retaining rings
• Modified pole connections of turbogenerator rotors to avoid cracks
• Upgrade of pole coil connections of hydropower generator rotors

We also provide upgrades of the efficiency by use of modern materials with reduced losses and by re-calculation and optimizing the winding data for a rewinding and/or restacking.
 

We are ready to support you with retaining rings, stator- and rotor-wedges, bearings and shafts, hydrogen sealing rings, Roebel bars, stator- and rotor-coils, ventilators and ventilator blades, insulation parts, slip rings and collectors, brush holders and brushes, (flexible) copper straps, coolers and more.

Parts that are not available any more, we can re-engineer and manufacture. We can also provide complete new rotors and stators, sets of coils or Roebel bars and re-wedging sets by reverse engineering.