- Docente: Andrea Cavallini
- Credits: 6
- SSD: ING-IND/33
- Language: English
- Teaching Mode: Traditional lectures
- Campus: Bologna
- Corso: Second cycle degree programme (LM) in Electrical Energy Engineering (cod. 9066)
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from Apr 22, 2024 to May 30, 2024
Learning outcomes
At the end of the course, the student can choose the most appropriate diagnostic techniques for an electrical insulation system and is able to start using the techniques, interpreting measurement results. He knows (a) the typical failure modes of high and medium voltage equipment; (b) the diagnostic techniques most used to identify local defects (weak points in the insulation systems) and bulk degradation, their limitations and interpretation.
Course contents
- Aging: thermal aging, electrical aging, multifactor aging. Probabilistic aging models. Miner’s law. Thermal classes.
- Weak points in electrical insulation systems: stress control systems, interfaces, triple junctions.
- Partial discharge measurement using charge-based and UHF system. Noise rejection and PD source identification.
- Inverter-fed machines: insulation systems, stress factors, partial discharges. Qualification.
- Power cables: typical failure modes. Global diagnostic tools (dissipation factor, dielectric spectroscopy, dissolved gas analysis). Detection of partial discharges. Water trees and their detection.
- Paper/oil insulated systems: characteristics and aging.
- The electrical insulation system of power transformers and its deterioration due to thermal aging in the presence of catalysts. Techniques for transformer drying. Bulk and local diagnostic techniques for transformer, bushings and on-load tap changers.
- Insulation system of rotating machines: resin rich, VPI and global VPI, conductive armor tape, stress control system, bracing systems. Aging mechanisms and typical failure modes. Bulk diagnostic tool and partial discharge detection online and offline.
Readings/Bibliography
Slides and notes provided by the teacher.
The documents are available for download on IOL.
Teaching methods
About 30% of the course consists of lab experiences.
Assessment methods
Oral examination
Teaching tools
The high voltage equipment in the lab. of innovation technology will be used to show how to use diagnostic systems.
Office hours
See the website of Andrea Cavallini
SDGs
This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.