Case study on SliteVind, Isle of Gotland
Slitevind AB owns 29 wind turbines in Sweden where 18 is on the island Gotland in Sweden.
10 wind turbines are located in the park Smöjen in the north part of the island. Smöjen consist of 4 Vestas V66 (1,5 MW), 4 Vestas V47 (0,66 MW) and 2 Enercon 0,5 MW.
The Vestas V66 was built in 1999, and the warranty period ended during 2004. Anders Gahne (owner and technician) wanted to install a system that could prevent the high cost of replacement of damaged gears in the wind park. In Sept 2004, the first SPM monitoring system was installed in mill nr 1504 (Vestas V66). The system VCM20 measuring the running condition on the main shaft, gearbox and the generators with SPM Spectrum online and vibration measurements with EVAM.
The first indication showed a reduced condition in the bearing located on the output shaft from the gear to the main generator during the beginning of 2005. The indication was increased values for the symptom BPFI (inner ring).
Later on the values increased even more and during a period in April with strong wind and high production, the values showed really high peaks (see diagram).
August 16 the team service from Vestas did the work to open the high speed end of the gearbox and replaced the damaged bearing and at the same time the bearings at the rotor end of the shaft. All work was done on site. The bearing showed a broken inner ring and some metal peaces had contaminated the oil that needed to be replaced as well.
The total cost for the repair was 10% of what the cost would have been to replace the gearbox.
3 more V66 wind turbines in Smöjen got their VCM system from SPM installed in July 2005.
- Shock Pulse transducers at main shaft bearings
- Shock Pulse and vibration transducers on gearbox
- Shock Pulse on main generator
- Shock Pulse on secondary generator
- Vibration on a cooling fan for the main generator
Click image to play/pause rotation.