The New York Power Authority (NYPA) has successfully piloted a robotic technology that can navigate inside a power transformer to effectively identify any operational issues while reducing unplanned down time and reducing risk to personnel. The new inspection tool marks NYPA’s latest investment in enhancing reliability and cost-effectiveness of its electricity generation assets and transmission network as part of New York State’s growing strength in technological innovation.

The inspection was carried out by NYPA as part of an Electric Power Research Institute (EPRI) project evaluating transformer inspection technologies at NYPA’s Robert Moses Niagara Power Plant in Lewiston.  The remote-controlled inspection submarine – an ABB TXplore robot – was submersed into an oil-filled transformer without requiring the removal of the oil from the transformer or a human inspection.

“Submersible robotic technology provides an unprecedented and time-saving opportunity to evaluate a transformer’s ability to operate reliably and make an educated decision about whether a system needs repair,” said Alan Ettlinger, NYPA’s senior director of Research, Technology Development and Innovation. “This is a good example of responsible asset management that will increase efficiency and reduce costs by identifying any potential issues before they become a problem.”

The project supports Gov. Andrew M. Cuomo’s focus on keeping New York State at the forefront of technological innovation and improving the reliable and cost-effective supply of electricity.

“This specific demonstration focused on the ease and speed of deployment, quality of the visual inspection, and typical inspection times when using robotic inspections of transformers,” said EPRI technical executive Luke Van der Zel, who helped lead the tests. “The results will guide future research on how this technology functions in highly contaminated, and therefore very dark, transformer oils.”

The toaster-sized robot can be used when a power transformer experiences unusual gas accumulation in the insulation oil and requires further investigation inside the tank to determine whether there is an internal defect in the transformer. The technology was developed by ABB and is part of an EPRI collaborative research project helping understand how to specify and apply these new inspection tools.

Conventional internal inspection requires the oil to be drained for an inspector to enter the transformer to verify there are no internal defects. After the inspection, the oil needs to be processed to ensure required quality of the oil – a process that could take several days. Moreover, the activity poses potential safety issues and a rescue team needs to be available in case the inspector faces an unexpected event inside the transformer’s tank.

The alternative approach is to utilize the commercially available submersible robotic technology that is capable of maneuvering inside a transformer and transmitting a live video feed that can be inspected from outside the transformer. The robot also was designed to be retrievable in case communication or power is lost.

At NYPA, a transformer had been operating in a satisfactory manner when it started to develop hot metal gassing in its insulation oil as a response to an unexpected event on the grid. An inspection by the submersible robot revealed an issue involving bits of insulating paper on the tank floor.  Based on the inspection, the transformer was taken out of service for repairs and replaced with a spare transformer so the generating unit could continue its operations.