We consider the problem of distributed generation and demand control for primary frequency regulation in power networks, such that stability and optimality of the power allocation can be guaranteed. It was shown in [1] that by imposing an input strict passivity condition on the net supply dynamics at each bus, combined with a decentralized condition on their steady state behaviour, convergence to optimality can be guaranteed for broad classes of generation and demand control dynamics in a general network. In this paper we show that by taking into account additional local information, the input strict passivity condition can be relaxed to less restrictive decentralized conditions. These conditions extend the classes of generation and load dynamics for which convergence to optimality can be guaranteed beyond the class of passive systems, thus allowing to reduce the conservatism in the analysis and feedback design.

The cubic form of SiC (βor 3C-) compared to the hexagonal α-SiC polytypes, primarily 4H-and 6H-SiC, has lower growth cost and can be grown heteroepitaxially in large area Silicon (Si) wafers which makes it of special interest. This in conjunction with the recently reported growth of improved quality 3C-SiC, make the development of devices an imminent objective. However, the readiness of models that accurately predict the material characteristics, properties and performance is an imperative requirement for attaining the design and optimization of functional devices. The purpose of this study is to provide and validate a comprehensive set of models alongside with their parameters for bulk 3C-SiC. The validation process revealed that the proposed models are in a very good agreement to experimental data and confidence ranges were identified. This is the first piece of work achieving that for 3C-SiC. Considerably, it constitutes the necessary step for Finite Element Method (FEM) simulations and Technology Computer Aided Design (TCAD).

Technology computer-aided Design (TCAD) is essential for devices technology development, including wide bandgap power semiconductors. However, most TCAD tools were originally developed for silicon and their performance and accuracy for wide bandgap semiconductors is contentious. This chapter will deal with TCAD device modelling of wide bandgap power semiconductors. In particular, modelling and simulating 3C-and 4H-Silicon Carbide (SiC), Gallium Nitride (GaN) and Diamond devices are examined. The challenges associated with modelling the material and device physics are analyzed in detail. It also includes convergence issues and accuracy of predicted performance. Modelling and simulating defects, traps and the effect of these traps on the characteristics are also discussed.

No abstract

No abstract

No abstract

No abstract

Major recent developments in growth expertise related to the cubic polytype of Silicon Carbide, the 3C-SiC, coupled with its remarkable physical properties and the low fabrication cost, suggest that within the next five years, 3C-SiC devices can become a commercial reality. It is therefore important to develop Finite Element Method (FEM) techniques and models for accurate device simulation. Furthermore, it is also needed to perform an exhaustive simulation investigation with scope to identify which family of devices, which voltage class and for which applications this polytype is suited. In this paper, we present a complete set of physical models alongside with our developed set of material parameters for bulk 3C-SiC aiming Technology Computer Aided Design (TCAD) tools. These are compared with that of 4H-SiC, the most well developed polytype of SiC. Thereafter, the newly developed material parameters are used to assess 3C-and 4H-SiC vertical power diodes, PIN and Schottky Barrier Diodes (SBDs), to create trade-off maps relating the on-state voltage drop and the blocking capability. Depending on the operation requirements imposed by the application, the developed trade-off maps set the boundary of the realm for those two polytypes which allows us to predict which applications will benefit from an electrically graded 3C-SiC power diodes.