Generator winding for ExxonMobil

ExxonMobil contacted Karsten Moholt regarding condition monitoring of the offshore generators. An electrical condition monitoring revealed a critical condition for the generator (partial discharge and tan δ measurements). A visual inspection revealed wear on the isolation (corona marks). Repair of the semiconductor layer in the stator was planned, but when the generator was disassembled the wear on the semiconductor layer was too extensive and rewinding the stator became the final solution.