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Research

PhD defence by Bjørn Rannestad on Methods of Monitoring and Reliability Improvement of Wind Turbine Converters

Time

16.05.2019 kl. 13.00 - 16.00

Description

Bjørn Rannestad, Department of Energy Technology, will defend the thesis "Methods of Monitoring and Reliability Improvement of Wind Turbine Converters".

TITLE

Methods of Monitoring and Reliability Improvement of Wind Turbine Converters

PHD DEFENDANT

Bjørn Rannestad

SUPERVISOR

Professor Stig Munk-Nielsen

MODERATOR

Associate Professor Szymon Michal Beczkowski

OPPONENTS

Associate Professor Deszo Sera, Dept. of Energy Technology, Aalborg University (Chairman)
Dr. Suresh Perinpanayagam, Cranfield University, United Kingdom
Senior Specialist Lars Helle, Vestas, Denmark

ABSTRACT

Condition monitoring systems for several of the mechanical and structural components of wind turbines are commercially available, but condition monitoring of the electronic components are not yet commercialized.

Bringing converter monitoring from the R&D laboratories to field wind turbine converters is a major contribution of the work performed in relation to this PhD thesis. A converter monitoring system named Converter Monitoring Unit (CMU) was designed and installed in a multi Mega Watt test wind turbine. Reference data (calibration data) were generated, based on field data alone. The temperature related parameters Virtual Temperature ( T v ), Relative Virtual Temperature ( T vr ) and Relative Virtual Temperature Difference ( Δ T vr ) were calculated based on reference data generated, and a full year of power module monitoring was shown with consistent results.

Inductive coupling between measurement circuitries and current carrying conductors distort the sampled signals, and several compensation strategies were proposed. In addition, a novel statistical method of estimating IGBT switching transition time ( t ˆ tr ), and a novel discontinuous interleaved modulation scheme was proposed. The latter drastically reduces diode switching losses. The methods presented are important steps in bringing cost-effective converter monitoring solutions into the field.

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PhD defence by Bjørn Rannestad on Methods of Monitoring and Reliability Improvement of Wind Turbine Converters

ALL ARE WELCOME. THE DEFENCE WILL BE IN ENGLISH.

AFTER THE DEFENCE THERE WILL BE AN INFORMAL RECEPTION AT PONTOPPIDANSTRAEDE 111 IN ThE COFFEE ROOM.

 

Host

Department of Energy Technology

Address

Pontoppidanstræde 111, auditorium 1.177