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In this paper, an efficiency and emissions evaluation framework for marine DC hybrid power systems is developed based on the physics- and data-based models of the power components. The proposed framework is tested under the operational profile of a real-case semi-submersible drill rig with all-electric propulsion and a suggetsed DC hybrid power system with batteries. The applied load profile, including propulsion, drilling, auxiliary, and hotel loads, shows high fluctuations, indicating the need for battery hybridization. In addition to the operational profile, the impact of the onboard power system configuration, sectionalized and common bus, on the emissions and efficiency has been studied. The results include the total energy efficiency of the ship powertrain from fuel to propulsion load and total CO2 emissions. For the considered vessel power system and operational profile, it is observed that the sectionalized bus configuration performs slightly better in terms of energy efficiency, and consequently fuel consumption and CO2 emissions.

This paper presents monitoring of ageing in high power insulated gate bipolar transistor (IGBT) modules subjected to sinusoidal loading at nominal power level. On-state voltage for IGBT, diode, and rise in interconnection resistance are used as ageing parameters. These are measured in three different ways: calibration of power modules after 24 h of operation, offline characterization every 5 min of operation, and continuous measurement during normal converter operation. Four power modules are tested, which are cycled to different degradation levels by number of cycles, where one is tested until failure. The characterization at different stages of lifetime indicates that the rise in resistance originates from thermo-mechanical degradation of interconnects. Post-test investigations: four-point probing and micro-sectioning indicate thermo-mechanical induced degradation of the chip topside interconnects as the source for rise in resistance. Major degradations are observed in bond wires and metallization on the low side diode.

An electrical four-point probing approach is used to estimate local degradation in high power insulated gate bipolar transistor modules subjected to power cycling. By measuring electrical parameters of selected units and components the possibility of mapping the degradation is demonstrated. The development of failures is put in accordance with physical phenomena and materials fatigue. These results are directly usable for reliability purposes with a focus on geometry optimization and enhanced lifetime prediction methods.

In this paper, both the main effects and interaction effects of parameters on CO 2 removal efficiency were investigated. Flue gas stream data from a 500MW coal power plant has been used for the model development. The complete removal process is implemented in Aspen Plus with selected operating conditions and parameters using Monoethanolamine as solvent. The base case model is developed in Aspen Plus with specific parameter values to achieve 85% removal efficiency. The CO 2 removal efficiency variation with different parameters; such as number of stages, inlet solvent flow rate, lean loading, temperature of the flue gas and solvent stream, absorber packing height and diameter and absorber pressure are considered as the most important parameters for sensitivity analyses. The data collected from simulations were analysed using Principal Component Analysis, Principal Component Regression and Partial Least Square-regression. The correlation between variables were studied, which indicate that inlet solvent flow rate, absorber packing height and diameter, absorber pressure and temperature of the solvent stream are positively correlated with CO 2 removal efficiency whereas the lean loading and temperature of flue gas are negatively correlated with efficiency.