J
Johann W. Kolar
Researcher at ETH Zurich
Publications - 1009
Citations - 44219
Johann W. Kolar is an academic researcher from ETH Zurich. The author has contributed to research in topics: Rectifier & Three-phase. The author has an hindex of 97, co-authored 965 publications receiving 36902 citations. Previous affiliations of Johann W. Kolar include Alstom & Infineon Technologies.
Papers
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Journal ArticleDOI
Half-Controlled Boost Rectifier for Low-Power High-Speed Permanent-Magnet Generators
TL;DR: A novel modulation scheme improving the power electronics efficiency is proposed using space-vector analysis and the integration into a compressed-air-to-electric-power system with a generator rotating at 350 000 r/min is presented, and the measurements verify the theoretical results with an efficiency increase of 2% for the novel modulation Scheme.
Proceedings ArticleDOI
Litz wire losses: Effects of twisting imperfections
TL;DR: In this article, the implications of imperfect twisting on the current distribution among the different strands of HF litz wires and the corresponding losses were analyzed by means of a fast 2.5D PEEC (Partial Element Equivalent Circuit) method.
Proceedings ArticleDOI
Electrical shielding of MV/MF transformers subjected to high dv/dt PWM voltages
TL;DR: In this article, the authors analyzed the electric field distribution (in the insulation, at the surface, and in the air) for a ±3.5kV/±400V, 50kHz, 25kW MV/MF transformer employed in a Solid-State Transformer (SST) demonstrator.
Proceedings ArticleDOI
A new switching loss reduced discontinuous PWM scheme for a unidirectional three-phase/switch/level boost-type PWM (VIENNA) rectifier
Johann W. Kolar,U. Drofenik +1 more
TL;DR: In this paper, the applicability of discontinuous modulation for a three-phase/switch/level PWM rectifier system is investigated and the increase of the effective pulse frequency is calculated analytically.
Proceedings ArticleDOI
Analysis of a Smith-predictor-based-control concept eliminating the right-half plane zero of continuous mode boost and buck-boost DC/DC converters
TL;DR: In this article, the authors use a boost converter as an example to show that application of the principle of linear prediction (as originally proposed for the control of systems with dead times) yields the mirror image of the control circuit zero.