Abstract

DC electric power distribution systems have higher efficiency, better current carrying capacity and faster response when compared to conventional AC systems. They also provide a more natural interface with many types of renewable energy sources. Furthermore, there are fewer issues with reactive power flow, power quality and frequency regulation, resulting in a notably less complex control system. All these facts lead to increased applications of DC systems in modern power systems. Still, design and operation of these systems imposes a number of specific challenges, mostly related to lack of mature protection technology and operational experience, as well as very early development stage of standards regarding DC based power infrastructure. This book provides an up-to-date overview of recent research activities in the control, protection and architectural design of a number of different types of DC distribution systems and microgrids. Practical requirements and implementation details of several types of DC distribution systems used in the real world industrial applications are also presented. Several types of coordinated control design concepts are shown, with concepts of stabilization being explained in detail. The book reviews the shortcomings and future developments concerning the practical DC system integration issues.

Abstract

While many have advocated for the use of Virtual Local Area Networks (VLANs) as a way to provide scalable traffic management, finding the optimal traffic split (mapping) among VLANs to achieve load balancing has turned out to be a very challenging and combinatorially complex problem to solve. This paper considers the traffic engineering problem in data center networks by studying the joint problem of finding spanning trees for VLANs and optimally selecting the most promising spanning trees to map the traffic flows onto. We mathematically model this problem using Integer Linear Program (ILP) techniques and follow a primal-dual decomposition approach, using column generation, to solve exactly a relaxed mapping version of the problem, as well we present approximate solutions to the original problem. We show through numerical evaluations an outstanding scalability of the decomposed version of the problem and we use our results to study the performance of traffic engineering protocols developed in recent literature for data center networks. NPRP 5-137-2-045 grant from the Qatar National Research Fund (a member of the Qatar Foundation). Scopu