In this paper, a space vector modulation (SVM) method for indirect matrix converters (IMCs) is proposed to improve the output voltage quality in high modulation index ratios and to reduce the peak common mode voltage (CMV). A novel approach in the rectifier stage modulation, generates a variable dc-link voltage that is controlled to drive the inverter stage on the limit of the linear modulation during each switching period. This allows inherent formation of the output voltage using only two active vectors per sector, which reduces peak CMV and enhances output voltage quality. Analytical and experimental studies are carried out to validate the feasibility and the benefits of the proposed modulation technique.

In many cities that have experienced rapid growth like Abu Dhabi, urban microclimate scenarios evolve rapidly as well and it is important to study the urban thermal dynamics continuously. The Local Climate Zone (LCZ) classification considers factors related to the physical properties like surface cover and surface structure of the city which allow to analyze urban heat flows. Abu Dhabi city is rapidly expanding and is characterized by highly heterogeneous types of built forms that comprise mainly of old mid-rise and modern high-rise buildings with varied degrees of vegetation cover in different parts of the city. The fact that it is a coastal city in a desert environment makes it quite unique. This paper presents an approach of studying urban heat flows in such heterogeneous setup. First, the city is classified into local climate zones using images acquired by Landsat Satellite. Numerical simulations are performed in the designated LCZs using a computational fluid dynamics software, Envi-met. The results of Envi-met are calibrated and validated using in-situ measurements across all four seasons. The calibrated models are then applied to study entire Abu Dhabi island across different seasons. The results indicate a clear presence of urban heat island (UHI) effect when averaged over the full day which is varying in different zones. The zones with high vegetation do not show large average UHI effect whereas the effect is significant in densely built zones. The study also validates previous observations on the inversion of UHI effect during the day and in terms of diurnal response.

Matrix converters (MCs), compared to traditional back-to-back converters, offer a series of advantages for ac-ac power conversion. However, increased realization complexity and cost have restricted the proliferation of MCs to a limited number of commercially available solutions. In this article, an efficient sparse matrix converter realization is presented as a step toward the development of simpler, lower-cost, and reliable realization architectures. In contrast to common practices that utilize a flexible logic fabric, such as a field programmable gate array or a complex programmable logic device, and a digital signal processor, the proposed implementation is based on a single commercial off-the-shelf microcontroller unit. This method is possible due to the novel implementation of a synchronous finite state machine that realizes the four-step commutation strategy required by the current source rectifier stage. Since the complete control scheme is implemented in one IC, it inherently avoids important MC realization issues, such as communication delays and synchronization between controllers. In addition, both software and hardware requirements are reduced and lower the overall development effort and cost.