Cutting-Edge UV Camera Technology Enhances Electrical Machine Diagnostics
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Add Your Heading Text Using a UV camera as a tool to help assess the condition of high voltage motors and power generatorsHere
Laborelec carries out condition assessment on rotating electrical machines as part of its mission to assist in operating and maintaining power plants and other industrial installations. For this kind of task, ultraviolet (UV) detection of partial discharges is fast, easy to carry out and interpret, and offers a high level of safety in high voltage situations. In short: it’s an investigation tool of choice.
Detecting partial discharges is widespread as a way of estimating the condition of the stator winding insulation in high voltage rotating electrical machines. Measurement can be achieved electrically — in-service or off-line — but alternative complementary methods are also available on the market, such as UV detection. For some years, Laborelec has been using an OFIL-branded UV camera in a wide range of situations involving power generators and motors, in power plants and other industrial sites.
Power generator diagnostic
When increased levels of partial discharge activity are detected (for example through in-service electrical measurement), it is common for additional measurements to be undertaken during an outage to clarify or confirm the diagnosis. Laborelec regularly uses an OFIL UV camera to assess various failure mechanisms. The camera allows immediate and safe localization of the origin of superficial corona discharges on end windings, for example, when generators are disassembled during planned outages.
Quality control after repair
When local repairs are carried out on end-windings, it is useful to compare certain features or measurement results before and after the repair. In a recent case, OFIL’s UV camera was used on a large turbogenerator to verify that corona discharges had decreased and that repairs had been carried out successfully. In addition, the UV camera is able to carry out this verification from a safe distance.
Motor diagnostics
When an HV motor is dismantled to make the stator winding accessible in a workshop setting, the UV camera greatly assists in identifying problems.
In particular, the camera helps locate superficial partial discharge issues from a safe distance. This is important since such tests are carried out in the presence of high voltages. The above images are from a recent case where a clear increasein external partial discharge activity, compared with previous measurements, was detected. In this case, as in the others, the UV camera made it possible to pinpoint the source of the partial discharges on the terminal leads from a safe distance. This improved the reliability of the diagnosis and gave more credibility to the repair recommendation.
Ofil’s UV camera is a very effective way to help identify defects in a wide range of industrial situations
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