Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Engineering
Thermal Features Vis A Vis Strain Features Of Fracturing Process In Jointed Rock Layer Under Concentrated Load, Haiqing Yang, Bolong Liu, Shivakumar Karekal
Thermal Features Vis A Vis Strain Features Of Fracturing Process In Jointed Rock Layer Under Concentrated Load, Haiqing Yang, Bolong Liu, Shivakumar Karekal
Faculty of Engineering and Information Sciences - Papers: Part B
In case of earthquakes and crustal movement, the concentration of impounding load over a large region of crust can cause disturbances to the stratum. In order to quantitatively investigate crack initiation, propagation and coalescence processes of jointed stratum based on thermal variations caused by concentrated mechanical loading, a series of indention tests were performed on granite specimens. In the experiment, fracture process and resulting infrared radiation fields of specimens were respectively recorded by synchronized digital image correlation system and infrared camera. Then, thermal characteristics of mixed shear-tensile and tensile conical crack were analyzed. Experimental results indicate that the highlighted temperature …
Power Loss And Thermal Impedance Modeling Of Multilevel Power Converter With Discontinuous Modulation, Md Mazharul Islam, Md. Ashib Rahman, Md Rabiul Islam
Power Loss And Thermal Impedance Modeling Of Multilevel Power Converter With Discontinuous Modulation, Md Mazharul Islam, Md. Ashib Rahman, Md Rabiul Islam
Faculty of Engineering and Information Sciences - Papers: Part B
The hard switching operation of the insulated gate bipolar transistor (IGBT)-based multilevel converters (MLCs) in the transformer less direct integration of renewable power plants produces a considerable amount of switching and conduction power loss. This eventually causes higher junction temperature and lower thermal stability. The third harmonic sixty-degree bus-clamped pulse width modulation (BCPWM) technique demonstrates reduced switching losses and better harmonic spectra. In this paper, an analytical model for calculating the average and the rms currents for the hard switching operation of IGBTs and antiparallel diodes (APDs) is proposed. Furthermore, to calculate the device turn-on and turn-off losses, a discrete …