Specialized diagnosis equipment let engineers pinpoint failures in wind turbine electronics.
Maintaining a wind farm is a constant, costly operation. For instance, service firm Frontier Pro Services estimates that 60% of U.S. wind turbines may be behind on maintenance. Also, AWEA estimates that more than $40 billion of U.S. wind installations will be out of warranty in 2011, and more than 75% of wind farms in the U.S. will be out of warranty over the next five years.
The good news is there are cost-saving options available for wind-farm operators in the form of turbine component repair. “Component repair from a qualified service provider can slice 30 to 70% off the cost of new OEM components,” says Jay Hollingsworth, spokesman for PSI Repair Services in Livonia, Mich. He adds that repair depots, such as PSI Repair, offer repair services for electronic, hydraulic, and precision mechanical components from all the major manufacturers that drive a wind turbine’s pitch and yaw system, as well as down-tower electronics. “The company has found it possible to repair printed circuit boards, PLCs, thyristors, pitch controls, SCADA, VRCC units, IGBT banks, gearboxes, hydraulic pumps and actuators, pitch motors, encoders and transducers.”
The IGBT on the left appears as it arrives for repair, and on the right, after repair. Every failed part within a GE IGBT can be repaired or replaced by PSI staff.
The component-repair process begins with a field technician removing what is believed to be a faulty component from the wind turbine and shipping it to the repair depot for evaluation. “Our company, for example, offers free evaluations and uses the latest diagnostic tools to detect electronic component failures down to the microchip level,” says Hollingsworth. After the problem has been identified and fixed, the depot tests the repaired component and ships it back to the wind farm. However, there are times when a legacy component is unsalvageable. “In these cases, a company like PSI offers remanufacturing services,” he says. “Such companies can bring the old, broken down components back to life, and, in some cases, improve upon the original design and performance.”
PSI Repair Director of Engineering Ron Fukui suggests companies first understand why components fail so they can track trends and implement corrective actions. “Without effective root cause analysis, it is nearly impossible for a wind farm to run efficiently,” says Fukui. “When wind farm operators have a more complete picture, they can make more informed decisions. That’s why it is important to pick a repair company that offers comprehensive engineering services.”
Fukui says the company repairs electronics most often. “In particular, we see quite a few hub converters – the motor drives on each blade. These drives pitch or twist turbine blades so they capture as much energy as possible from the wind.” Overheating is the most common cause of electronics failures Fukui adds. PSI fixes this issue with upgraded capacitors, which let the unit run cooler, and, ultimately, extends its life. “In cases of catastrophic failure, we can manufacture new bus boards that increase the successful salvage rate to 100%.”
Fukui says other components repaired frequently include IGBTs. “This is an Integrated Gate Bipolar Transistor, a special type used to switch high-power signals. They convert ac from the generator to dc, and then convert back to ac at the line frequency of 60 Hz.
The most common cause of failure for this component is aging and electrical noise. “We can repair or replace every possible failed part within an IGBT. This includes the IGBT itself, AEBM cards, bus bars, insulators, cables and more. We can even provide custom reusable packaging,” says Fukui. WPE
Filed Under: Components
