When considering safety concerns with wind turbines, two main topics come to the top—technician safety and turbine safety. Technician safety prevention typically revolves around protective clothing, climb-assist technologies, and best practices in the field.
Increasingly, companies are using rope-access techniques to perform work on wind turbines. Rope access technicians are highly-trained individuals providing safe and efficient turbine cleaning, inspections, and blade repairs. The use of heavy cranes and lifts are costly and can often increase turbine down-time due to transportation and set-up limitations. Blade inspections, light blade repairs, and tower cleaning and servicing can be performed more efficiently by a team of qualified rope-access technicians. As this trend continues, suppliers are providing less-expensive and safer products.
While worker safety is the number one concern for turbine operators, it’s also important to keep in mind the safety of the turbine. Turbines typically stand 60m to 80m and are more than likely the highest object for miles. As such, wind turbines are extremely susceptible to lightning strikes. In fact, most turbines will experience multiple lightning strikes during their operating life. When lightning surges through a wind turbines electrical system it can cause severe damage to equipment such as control electronics, power converters and power transformers. Approximately 50% of all electrical failures in a wind turbine are caused by these strikes. Current grounding solutions have been somewhat successful, but as you can see by the high number of electrical failures caused by lightning, innovations are still needed.
A recent lightning receptor developed by ERICO out of Solon, Ohio helps protect wind turbine blades and was recently tested to IEC 61400-24, the conformance required by Germanischer Lloyd for GL Certification. The receptors are also tested for a 20-year estimated service life, exceeding IEC requirements for Arc Entry and Conducted Current Tests.
In addition to lightning protection, emergency braking systems are crucial to safe operations in the case of critical equipment malfunctions. For example, if the generator overheats or is disconnected from the electrical grid, the usual resistance applied to the driveshaft will cease and the rotor can accelerate rapidly within a matter of seconds.
The WBA1-75-SC from Carlisle Industrial Brake and Friction has been specifically designed to meet the requirements of wind turbine rotor braking applications, where guaranteed stopping and holding performance is required in both emergency and routine maintenance situations. This system is designed for gearbox mounting and features a floating brake caliper. This enables the brake to self-center on the brake disc during operation and adjust axial displacements in the drive train.
Filed Under: Safety