GE's Power Services business has signed an agreement to deploy its DIRIS and TurboRotoscan robotic tools to inspect utility Alinta Energy's gas-fired power plants in Australia and New Zealand. The inspection systems are designed to alert the utility to potential generator issues and give it time to evaluate its options. The project was developed through GE's Alstom power generation business, which it acquired in November last year.
"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 biggest win for us was the ability to use this technology on non-GE units and apply it across our whole fleet" commented Gareth Williams, manager of engineering services for power generation at Alinta.
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 in Australia and New Zealand
The DIRIS robot will perform critical tests of the generator stator iron core laminations, stator radial wedging system and conduct 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 utilising 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 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 to the stator winding insulation system.
The robot technology 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 in April 2016, and under the present agreement continued until 2020.