Suzlon Energy Ltd. has completed its worldwide program to strengthen and reinforce all Suzlon blades of the V2 type on its S88 2.1 MW turbine fleet.
Instances of blade cracks were first discovered in late 2007 during the operation of some of Suzlon's S88 wind turbines in the U.S. As a result, the company launched a detailed root-cause analysis and identification process, followed by extensive testing of the solution and a comprehensive retrofit operation to safeguard and enhance 1,251 S88-V2 blades around the world.
The retrofit process was carried out in a multi-stage process, according to Suzlon. The company worked with its customers and engaged Navigant Consulting to conduct an extensive root-cause analysis (RCA) examining all primary and secondary contributing causes to the blade-crack issue.
The RCA team concluded that the S88-V2 blade design, while designed and tested to industry standard certification guidelines, had a weakness in the transition area – about 6 meters from the root of the blade. The blades measure 43 meters long and weigh 7 tons.
At the completion of the program, 179 blades of the total fleet of 1,251 blades developed cracks. However, Suzlon upgraded the entire fleet.
To resolve the blade-cracking issue, Suzlon added three additional plies of fiberglass to the blade's exterior in the transverse direction. These plies extend over the entire blade surface in the transition area.
According to the company, the new reinforced S88-V2 blade has lower stress and strain level in the transition area, preventing cracks from forming. Suzlon worked with Germany-based Germanischer Lloyd to test and certify the V2 blades according to international standards.
SOURCE: Suzlon Energy Ltd.
