Power Plants Deploy Robots to Inspect Generators

Building on its recent Alstom acquisition, GE Power Services has been contracted to inspect 19 generators at seven Alinta Energy power plants in Australia and New Zealand.

GE’s recent acquisition of Alstom—its largest industrial acquisition ever, completed in November—figured significantly in the reorganization of GE’s business, including the formation of GE Digital and GE Automaton & Controls. One of the latest projects to come to fruition was one developed through Alstom and now showcasing GE’s expanding predictive maintenance portfolio for power plant operators.

GE’s Power Services business has signed an agreement to deploy advanced robotic inspection tools to inspect Alinta Energy’s gas-fired power plants in Australia and New Zealand. GE’s Diris and TurboRotoscan inspection systems—endorsed by Alinta Energy’s insurance company as a best practice for gas power plants—will alert the utility to potential generator issues to give it time to evaluate its options.

“We worked closely with GE’s team and our insurance company to demonstrate the benefits of the Diris and TurboRotoscan technologies for ensuring effective generator inspections,” said Gareth Williams, manager, engineering services—power generation, Alinta Energy. “Proving the technology’s reliability was important because the generator monitoring system provides the current condition of the generator and indicates any issues or early warnings of failures. It also provides us with greater flexibility as the inspection work can be done while the generator rotor remains in place.”

The robotic systems will enable faster generator inspections because of the ability to perform the inspections without removing the rotors from the machines. But another key benefit for Alinta Energy was the ability to apply the technologies to non-GE units to apply them across the whole fleet, Williams said. “This makes such inspections quicker and easier to perform and is endorsed as a best practice by our insurance company, which indicates that most generator claims arise through rotor removal and replacement activities,” he said.

Under the terms of the inspection agreement, GE will inspect 19 generators manufactured by GE, Alstom, Mitsubishi and Brush at seven of Alinta Energy’s gas-fired power plants.

“Predictive maintenance activities are essential to reduce costs and increase gas power plant reliability and efficiency,” said Anders Maltesen, general manager for GE’s Power Services business for the Asia-Pacific region. “By adding these inspection technologies to our existing services portfolio, we now offer total plant solutions to operators around the world, whether their equipment comes from GE, Alstom or other OEM suppliers.”

The Diris robot will provide Alinta Energy with modern robotic instrumentation and tooling to allow fast and reliable remote inspection of the turbogenerator. It performs critical tests of the generator stator iron core laminations and stator radial wedging system, and conducts a visual (video-type) inspection of the inside surfaces of the rotor and stator. These tests would normally be part of a typical overhaul regime after a lengthy process of removing the rotor and using manual and semi-automated tooling. The low flux test permits the identification of short circuits between the stator iron core laminations, which could otherwise develop into critical hot spots and severely damage the generator. The tightness test of the radial wedging system permits identifying loose wedges, which could otherwise promote movement of the stator bars and damage the stator winding insulation system.

TurboRotoscan will perform inspections of the generator retaining rings while the rotor remains in place and while the retaining rings are mounted on the rotor. The scanner also contains an eddy current probe to check the retaining ring outside surfaces.

The new generator inspections will begin next month and be performed through 2020.

 

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