Voltage Distribution in the Windings of Medium-Frequency Transformers Operated with Wide Bandgap Devices
| Autor: | Andrea Cremasco, M. Curti, Elena A. Lomonova, Daniel Rothmund |
|---|---|
| Přispěvatelé: | Electromechanics and Power Electronics, Electromechanics Lab, Cyber-Physical Systems Center Eindhoven, EIRES System Integration, EAISI Foundational |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Materials science
Energy Engineering and Power Technology Litz wire 02 engineering and technology engineering.material law.invention law 0202 electrical engineering electronic engineering information engineering 0501 psychology and cognitive sciences Electrical and Electronic Engineering Transformer 050107 human factors medium-frequency transformer (MFT) insulation business.industry solid-state transformer (SST) 020208 electrical & electronic engineering 05 social sciences Electrical engineering wide bandgap (WBG) devices High dv/dt Electromagnetic coil Harmonics Rise time Partial discharge engineering business Pulse-width modulation high-frequency model Voltage |
| Zdroj: | IEEE Journal of Emerging and Selected Topics in Power Electronics, 10(4):9373403, 3587-3602. Institute of Electrical and Electronics Engineers IEEE Journal of Emerging and Selected Topics in Power Electronics |
| ISSN: | 2168-6777 |
| Popis: | The short rise time observed in the PWM voltages generated by ultrafast wide bandgap devices increases the amplitude of voltage harmonics at higher frequencies. These harmonics can excite the resonances of medium-frequency transformers (MFTs), resulting in overvoltages inside the windings during continuous operation. Without further measures, these overvoltages can lead to unexpectedly high electric fields in the insulation material, which can result in partial discharge, accelerated aging, and possible failure of the MFT. To avoid these effects, the mechanism causing the overvoltages has to be understood and quantified during the design process. Based on this, the MFT can be designed in a way that the overvoltages vanish or are tolerable. Therefore, the voltage distribution inside the MFT windings is analyzed by a fully coupled multiconductor transmission line model, which includes the damping effect of electromagnetic losses in the litz wire and the core. This method is verified by measuring the transfer functions of the voltage to ground of individual turns and their voltage waveforms during continuous operation. The waveforms indicate repeating overvoltages inside the windings. A guideline for the design verification and a simplified approach to speed-up the modeling process are presented. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|