Maintaining the performance and profit-generating capacity of your wind farm begins with load bank testing and a strong maintenance plan. Wind turbines are complex pieces of equipment that are continuously exposed to the elements. Each individual turbine requires extensive mechanical and electrical maintenance to avoid significant downtime and lost production.This guide will help you build a wind farm maintenance plan design to extend the life of your turbines.
Components of a Wind Turbine
The three main parts of a typical wind turbine include: the tower, rotor, and nacelle.
- Tower Contains cable lifts, ladders, and lighting.
- Rotor Includes blades connected to a hub and pitch drive.
- Nacelle Contains the gear box, low and high-speed shafts, generator, controller, brake, head exchanger, anemometer, wind vane, and yaw drive.
Building a Wind Farm Maintenance Plan
By creating a rigorous maintenance plan and paying special attention to the data produced you can monitor your turbine’s conditions, build a historical timeline for how your equipment is running, avoid failures, and increase energy production.
Start With Load Bank Testing
Load bank testing is not just for commissioning your new wind farm, it is also the first step in conducting a routine maintenance plan. By load testing the generator of your wind turbines you will have a baseline understanding of how effectively your turbines are converting wind into electricity and are able to uncover potential issues. If a disruption is discovered it can be corrected quickly to ensure it does not lead to poor turbine performance, an outage, or expensive repairs.
Work Through The Turbine Components
While each individual element of a wind turbine needs to be inspected on a regular basis, there are a few components that exist in different sections of the turbine that follow similar maintenance practices.
Bearings
- A variety of bearings can be found in the blade pitch, yaw drive, main shaft, and gearbox.
- Most of the bearings in your turbine are designed specifically for your wind farm, making it difficult to create a standardized maintenance plan that will work across all bearing types.
- The bearing manufacture will make recommendations on proper installation and maintenance practices for each variation. When these recommendations are followed, you can avoid any issues outside of typical wear and tear.
Bolts
- Bolts are included in the nacelle, tower, and foundation.
- Bolting is the process of applying a bolt load to tighten these bolts. Bolt loads can be applied by using either torque or tension.
- The bolt manufacturer will recommend the right tools needed to apply either torque or tension to ensure each bolt is properly assembled and maintained.
Cables
- Cables can be found in the tower and in multiple parts in the nacelle.
- Common causes of cable damage include overloaded cables and exposure to external elements, lubricants, and mechanical stress.
- Cables need to be checked for cracks and for hardened conductor material. Cracks in the cable jacket indicate that the cable needs to be replaced by a cable with higher resistance properties.
- If hardened conductor material is found, it indicates that the current carrying capacity has overloaded the cable.
Hydraulics
- On turbines rated over 3 MW, hydraulics are used to pitch the blades. Additionally, hydraulics are used to operate the disk brake in the rotor and drive train.
- Proper maintenance of wind turbine hydraulics includes an inspection of the pistons and rotary joint to gauge wear and tear, and checking hydraulic fluid levels.
- The accumulator, or hydraulic battery, that continues to operate the pitch control in the event of power loss should be load tested on a regular basis to ensure it is retaining enough power supply to work during an outage.
Encoders
- These sensors are located in a variety of areas in the rotor and nacelle.
- Since their data is utilized to determine accurate and reliable blade pitch-control, it is vital to ensure all encoders are functioning properly.
- Heat, vibrations, and hydraulic fluid are the main elements that harm encoders.
- In addition to inspecting each encoder on a regular basis, following the manufacture’s recommended maintenance process and avoiding over-taxing the wind turbine will keep encoders running properly.
Common Issues
Typical reasons for wind turbine failures stem from incomplete maintenance, lack of lubrication, and missing warning signals. During the inspection of each element of the turbine look for proper lubrication of each component, check the cleanliness of filters, and ensure that all seals are properly sealed.As you are working through each component of the wind turbine, complete a vibration analysis, wear analysis, lube sample analysis, and load test. This data will tip you off to any potential problem areas that can be further examined.Wind turbines are exposed to some of the harshest climates and are often located in regions that are difficult to access. A customized wind farm maintenance plan will ensure the longevity of your turbines.As a leader in load bank testing, Comrent offers an expertise in wind farm commissioning and maintenance. Check out our latest case study to find out how we completed load tests for 100+ wind turbines with no grid power.
