November 5, 2007

Exploding wind turbine transformer

In response to a Nov. 1 query from a concerned citizen for information concerning reports of an explosion in one of the transformers at the "Maple Ridge" wind energy facility on Tug Hill, N.Y., and a truck working in the middle of the night at the base of each turbine, wrote on Nov. 2:
We've checked out the situation and there appears to be no truth to the report.
But (Jack Nasca) wrote on Nov. 5:
We spoke to the operators at the Maple Ridge site and have learned:

On July 4, a single pad mounted grounding transformer located at the Rector Road substation exploded and was rendered inoperative. This was one of ten such transformers in the substation. No cause was determined, and the transformer has been sent back to the manufacturer for an analysis to identify the cause. Lightning was not a factor. None of the other nine grounding transformers at the substation had any problems, and there have been no incidents at turbine base transformers.

Unrelated to the above, a program of annual preventative maintenance of transformers at the base of the turbines was conducted over the summer. This included an analysis of the mineral oil used as a coolant. A gas analysis of the cooling oil was conducted, which indicated elevated levels of certain gases in about 30% of the transformers, one of which was hydrogen. A contractor specializing in purging gases from transformer cooling oil was hired to remove the gases identified in the analysis. Because the contractor was very busy (apparently this occurs with some regularity with transformers in any type of transmission facility), they worked 24/7 for a 2 ½ week period to complete the task. So at some point they were working at "midnight." The process involves withdrawal of the oil from the transformer, piping it to a truck with the purging equipment, capture and collection of the gas for disposal off-site, and returning the oil to the transformer. It was stated that there is no atmospheric release of gases from this process.
wind power, wind energy, wind turbines