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Analysis of distributed energy systems (DESs) is more challenging, as multiple energy sources are connected with different loads through power electronics converters. Modeling and simulation become an essential step during the design stage, prior to actual implementation. These DESs comprised numerous converters in various configurations, e.g., parallel and cascade. This paper presents behavioral modeling technique for interconnected converters that can be used to predict dynamics of overall system. First models are developed for two converters in parallel and cascade configuration using direct approach (DA). The model derivation using DA becomes too complex for larger systems. A new transformation-based approach (TBA) is proposed, which, unlike DA, is simple and can easily be extended to model N interconnected converters. In this method, the measured g -parameter set is transformed to another domain, equivalent model is computed simply by the addition or multiplication of transformed g -parameters and then the equivalent model is transformed back to g -parameter set. The modeling techniques are implemented in Matlab/Simulink. The results from DA and TBA are compared, and their close agreement suggests that the new TBA can be used for the analysis of interconnected systems, comprised of multiple parallel and cascade converters. [ABSTRACT FROM AUTHOR]

Despite attractive thermal and electrical characteristics, wide band-gap semiconductor devices such as SiC MOSFET have struggled to penetrate in aircraft applications because of reliability issues in earlier releases. The second and third generation SiC MOSFETs have achieved improved reliability using high quality oxides and innovative fabrication process. This paper presents a failure rate model for SiC MOSFET based on the accelerated test data at a given operating condition. The proposed model enables the system level reliability analysis of second generation SiC MOSFET-based converters. The reliability of SiC two-phase synchronous boost converter has been evaluated at two different operating conditions: 10 and 16 A load condition. To predict the life time of the converter even after a chain of component failures, Markov's reliability model of the converter is developed. The state transition probabilities and mean time to failure (MTTF) of SiC converter are compared against its Si counterpart which shows that second generation SiC MOSFETs are for aircraft applications with high reliability. [ABSTRACT FROM AUTHOR]