After a wind tech identifies an ailing component on a turbine, the natural reaction is to replace it with a recommended version from the OEM. But when they stop supporting a turbine or a complex outsourced component, maintenance crews are forced to look elsewhere. Those OEM business decisions have initiated the rise of repair services.
A growing trend in the larger O&M scheme of things has wind turbine maintenance companies looking for repair services to support their work. Commonly repaired components include printed circuit boards, pitch drive systems, inverters, IGBTs, PLCs, VRCC units, AEBIs, proportional valves, hydraulic pumps, pitch and yaw motors, encoders, slip rings, transducers, and more.
This trend toward rebuilt parts is becoming more pronounced because the independent service providers (ISPs) tend to improve on what turbine OEMs have designed. For instance, one ISP says repair prices are typically half the cost of new parts, a good reason to consider repaired parts. To some extent, OEMs are encouraging the trend when they no longer support their equipment. This encourages repair ISPs to drive other trends, such as:
Rebuild, not just repair
– The companies in this space caution that “repair” is general term implying the repaired part is as good as the old part. More than simply repaired to OEMs specs, the companies say they have taken the time diagnose the problems and improve on original equipment. The most common product upgrade performed, according to the company, is to printed circuit boards. One ISP says that when it is working on a Clipper Xantrex Matrice, the company provides new cables, cleans and machines heat sinks so they adhere tightly to a new waterproof gasket, polishes IGMT mating surfaces for an improved thermal junction with the heat sink, adds fault protection circuitry to the advanced IGBT driver modules, and uses a new generation of IGBTs.
– This is the big trend. One engineering service enhances legacy components with newer, more reliable technology to improve performance and extend the component’s life. The company says it uses the latest diagnostic tools to detect failures down to the microchip.
Two widely used products that get upgrades are the GE 1.5 MW S Series Xantrex Matrix Inverter and the Clipper 2.5 MW Xantrex Inverter. These drop-in replacement designs let wind farms supplement shrinking inventories with more dependable, longer-lasting products, while keeping the turbines online. The effort is to provide comprehensive remanufacturing services for unsalvageable, obsolete components.
Modifications to products can result in universal fits where, for example, left and right hand design were once necessary. And when improved parts run cooler, for instance, they tend to run longer so their spares are unnecessary.
– When components are readily available, O&M crews need not maintain inventories in their own facilities which further trims their costs.
Longer warranties – With improved replacement components, ISPs can warranty more equipment with longer warranties than the original equipment carried. One says it warrants rebuilt parts for 18 months from time of purchase.
– These involve maintaining stock of many surplus parts to help clients get their production equipment back up and running. ISPs offers component repair along with engineering services for GE, Vestas, Siemens, Clipper, and other wind turbines. Furthermore, rebuild services are extending beyond electronic parts to now include hydraulic and precision mechanical components that drive the turbines’ pitch and yaw systems, as well as down-tower electronics.
Article originally appeared on Windpower Enginerring & Development in May 2014.
Paul Dvorak has been editor of Windpower Engineering & Development magazine since its launch in 2009 and has been writing and editing technical magazine for over 28 years. At one time or another he worked on a medical magazine and served as the CAD and CAM editor for a general purpose engineering magazine. Over his career, Dvorak has won several awards for his writing and editorials. He is a degreed mechanical engineer and Air Force veteran. Paul Dvorak resides in Cleveland, Ohio.