Remote condition monitoring brings big savings for wind farm

For wind farms, any unplanned downtime caused by damaged wind turbine drive train components can have significant economic consequences in terms of lost production and costly repairs. To avoid this, Geolica required a condition monitoring system for its wind turbines, which would detect any signs of damage to drive train components at an early stage, avoiding any unplanned downtime and giving the company an opportunity to plan any necessary remedial or maintenance work.

As Geolica had little experience of condition monitoring systems and analysing vibration data, the company also required a remote monitoring service and technical support from the condition monitoring system supplier. Geolica operates two wind farms in Spain with a total installed power base of 84.8MW. The wind farms, San Juan de Bargas and Santo Cristo de Magallon, are located in Aragon.

At the San Juan de Bargas wind farm, Schaeffler has a total of 56 FAG WiPro s condition monitoring systems installed - one on each wind turbine. The wind turbines are rated at 800kW with a height of between 52m and 59m and a generator speed of 1500rpm. The 8-channel FAG WiPro s system continuously monitors the condition of the main rotor bearings (one sensor), gearbox bearings (three sensors) and generator bearings (two sensors). Schaeffler also provides remote monitoring services on a 24/7 basis. This includes a monthly condition monitoring report, as well as an alarm report if measured values move outside of their normal range.

Schaeffler's FAG WiPro s is an online condition monitoring system that is suitable for the permanent monitoring of wind turbines. The system is compact, offering a high degree of flexibility for end users. The system combines all control modules into a single compact housing, enabling easy installation in control cabinets. The integrated multiplexer enables the recording of signals from up to eight different sensors.

FAG WiPro s monitors vibration conditions, which if left undetected, can cause costly unplanned shutdowns of wind turbines. These conditions include damage to bearings and gears, as well as shaft misalignments. If a specified threshold value or alarm limit is exceeded, the system triggers an alarm. The vibration monitoring data can be analysed directly on site at the central control station or this data can be retrieved via a TCP/IP communications link and analysed by either the end user or by Schaeffler.

Condition-based maintenance strategy

Since installing the FAG WiPro s systems at the San Juan de Bargas wind farm, vibration measurement data is continuously monitored by Schaeffler's Online Monitoring Centre. Schaeffler provides Geolica with detailed information about the wind turbines, which has enabled the company to adopt a condition-based maintenance strategy. Thanks to the FAG WiPro s systems and Schaeffler's online remote monitoring support, costly damage to drive train components has already been prevented on several occasions.

For example, 2 years after installing the condition monitoring systems, early signs of damage were detected to the raceway of the inner ring and rolling elements on an intermediate speed shaft bearing on a wind turbine gearbox. The total cost of replacing this bearing was EUR9500. However, if the damage had not been detected, the cost of a new gearbox would have been around EUR100,000. Therefore, allowing for the annual cost of providing a remote monitoring service for Geolica (EUR9000), the cost savings achieved were EUR81,500.

For more information about FAG WiPro s condition monitoring systems, please email [email protected] or visit the website at www.schaeffler.co.uk.