Comprehensive Investigation of Promising Techniques to Enhance the Voltage Sharing among SiC MOSFET Strings, Supported by Experimental and Simulation Validations

This paper comprehensively reviews several techniques that address the static and dynamic voltage balancing of series-connected MOSFETs. The effectiveness of these techniques was validated through simulations and experiments. Dynamic voltage-balancing techniques include gate signal delay adjustment methods, passive snubbers, passive clamping...

Aging of oil-impregnated paper at different frequencies

In this work, breakdown strength and lifetime curve of oil-impregnated paper (OIP) are compared at 50Hz and 1500 Hz. For the ramp breakdown tests, sinusoidal voltage ramp of 1 kVp/s is used. The ramp breakdown experiments is conducted on OIP samples made of single and double sheets of OIP. Weibull plots and interpretation of the results are...

Ramp sinusoidal breakdown of epoxy resin under high voltage waveforms at different frequencies

In this study, the immediate time to breakdown for pure epoxy resin is measured by applying a ramp sinusoidal voltage signal at certain frequency (50Hz, 500Hz and 5000Hz) until breakdown occurs. The HV testing procedures, epoxy resin sample and experimental set-up preparation and Weibull analysis of obtained results are elaborated. The...

Experimental study of epoxy surface discharge under different frequencies

With widely use of power electronics in medium voltage level, there is increasing concern about behaviour of insulation material under arbitrary voltage stress. Solid-gas insulation is a general choice in medium voltage level. Therefore, it’s unavoidable to encounter surface discharge problem. In this paper, the surface discharge on epoxy-air...

Impulse voltage distribution on disk winding: Calculation of disk series capacitance using analytical method

Nonlinear voltage distribution along the transformer winding during a lightning overvoltage can cause severe electric stress specially to the area of the winding close to the high voltage terminals. For high voltage transformers different methods such as interleaved winding, electrostatic shield wires, and wound-in shield wires are implemented...