On-Site Condition Assessment of High-Voltage Insulation Systems in Rotating Machines
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An unplanned outage of motors or generators can lead to high follow-up costs. To prevent those unexpected occurrences, it is essential to know the condition of the machine. In regards of the insulation system, high voltage tests such as the voltage withstand test, the dissipation factor and the off-line partial discharge (PD) measurement are worldwide accepted methods to determine the insulation status.
Beside the benefits of these tests, an external high voltage source is required which can fulfil the special onsite requirements such as:
- Modularity and portability due to limited space especially in industrial application.
- Fast assembling and dismantling due to short standstill times.
- Accurate measurements under onsite conditions.
The contribution intends to illustrate the possibility to perform reliable condition assessment fulfilling the listed requirements by using a compact and modular parallel resonance circuit. With this approach capacitances up to 1 µF and 12 kV can be tested in compliance with all relevant international standards.
The benefits of measuring partial discharges on rotating machines is shown, considering the critical parameters of the measurement. With practical examples the benefits of the offline tests and their specialities are described.
Concluding the contributions shows several use cases, demonstrating the practical use under onsite conditions with findings of faults.
Fabian Oettl is product manager at OMICRON electronics in Austria. In his role, he is responsible for rotating machines testing and diagnostic equipment. Before he joined OMICRON, Fabian was working in the R&D department of a manufacturer of large generators as high voltage insulation specialist. He received his MSc. Degree from Graz University of Technology in 2011.
He has written many scientific and technical papers and contributes to different working groups of Cigre and IEC.