The full-bridge converter with current-doublet synchronous rectifier (FB-CDSR) is a promising topology to implement low-voltage high-current power supplies. This paper proposes a novel control for this converter, whic...
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The full-bridge converter with current-doublet synchronous rectifier (FB-CDSR) is a promising topology to implement low-voltage high-current power supplies. This paper proposes a novel control for this converter, which provides the following features: fast transient response, fixed switching frequency, and high robustness against large-signal disturbances in the input-voltage and the load-current. Furthermore, this controller avoids the use of any current sensor and can be implemented by means of cheap analog circuits, which highlights its low-cost and simplicity. The parallel operation of several HB-CDSR is also discussed Finally, experimental results are provided in order to show the validity of the proposed control technique
In this paper, a method for the parallel operation of inverters in an ac-distributed system is proposed. The paper explores the control of active and reactive power flow through the analysis of the output impedance of...
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In this paper, a method for the parallel operation of inverters in an ac-distributed system is proposed. The paper explores the control of active and reactive power flow through the analysis of the output impedance of the inverters and its impact on the power sharing. As a result, adaptive virtual output impedance is proposed in order to achieve a proper reactive power sharing regardless of the line impedance unbalances. A soft-start operation is also included, avoiding the initial current peak, which results in a seamless hot-swap operation. Active power sharing is achieved by adjusting the frequency in load transient situations only, thanks to which the proposed method obtains constant steady-state frequency and amplitude. As opposed to the conventional droop method, the transient response can be modified by acting on the main control parameters. Linear and nonlinear loads can be properly shared due to the addition of a current harmonic loop in the control strategy. Experimental results are presented from a two 6-kVA parallel-connected inverters system, showing the feasibility of the proposed approach.
We develop a new software layer called the Automatic Parallel Detection Layer (APDL) for the automatic transformation from sequential to parallel code. The main interest, in this research, is the parallelism at loop l...
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We develop a new software layer called the Automatic Parallel Detection Layer (APDL) for the automatic transformation from sequential to parallel code. The main interest, in this research, is the parallelism at loop level, because significant parallelism in programs almost invariably occurs in loops. The proposed APDL has five processes for code transformation: the sequential source code parser, data dependence analysis of this code, partitioning, scheduling both task and data, and generating parallel source code. Many cases have been studied to evaluate the performance of the developed layer. The performance is evaluated depending on the execution time of: the sequential code, the parallel programmer code, and the code output from APDL for the same case study. Performance results show that APDL greatly improves the execution time with respect to sequential execution time, and saves on the high cost of a parallel programmer.
作者：
Kochs, HDDieterle, WDittmar, EProf. Dr.-Ing. Hans-Dieter Kochs (1943)
VDE is head of the Department of Computer Science and Information Processing Systems at the Gerhard Mercator-University of Duisburgl Germany. He received the Dip1.-Ing. degree in Electrical Engineering and the Dr.-Ing. degree from the RWTH Aached Germany in 1972 and 1976 respectively. From 1979 to 1991 he was system engineer and division leader in the areas of R & D of highly-reliable large-scale control and information systems (AEGIDaimler FAG-Kugelfischer). Since 199 1 he has been Professor at the University of Duisburg. His current R & D areas are reliability safety and fault tolerance of technical systems especially automation systems and hybridknowledge based systems including fuzzy-logic and neural networks. (Gerhard-Menxitor-University-GH Duisburg FB 71FG 10 Lotharstr. 1 D-47048 Duisburg T +49203/379-2204 Fax +49203I379-2205) Dipl.-Ing. Werner Dieterle (1966). VDE
received his degree in Electrical Engineering (Dip1.-Ing.) from the Technical University of Karlsruhd Germany in 1991. After having finished his studies he joined the scientific staff of the department of Computer Science and Information Processing Systems at the Gerhard-Mercator-University of Duisburgg Germany. His research interests include design of highly-reliable distributed computer control systems with particular focus on system communication. (Gerhard-Mercator-University -GH Duisburg FB 7/FG 10 Lothantr. 1 D-47048 Duisburg T +49203/3793483 Fax +49203/379-2205) Ing. (grad.) Ewald Dittmar (1943)
received his degree in Electrical Engineering from the school of engineering in Mannheim/Germany. Since then he worked for different industrial companies and utilities. Since 1988 he has been with ABB/Germany where he cumntly is head of the strategy department of ABB Network Control and Rotection. He investigates new development strategies for modern control systems hardware and software architecture in the area of energy transmission and distribution. (ABB Netzleittechnik GmbH. Wallstadter S
The paper presents the results of an application-based reliability study of distributed computer controlsystems with very high reliability demand, e.g. for supervision and control of power plants and energy distribut...
The paper presents the results of an application-based reliability study of distributed computer controlsystems with very high reliability demand, e.g. for supervision and control of power plants and energy distribution systems. A reliability classification scheme is presented and typical redundant control system structures are evaluated and classified due to their system reliability Special focus is placed on assessing the influence of the communication system on total system reliability.
A research project that addresses the efficacy of expert systems techniques for improving effectiveness of missile employments from Navy surface ships is discussed in terms of general weapon systems operations, specia...
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A research project that addresses the efficacy of expert systems techniques for improving effectiveness of missile employments from Navy surface ships is discussed in terms of general weapon systems operations, special requirements of real-time tactical situations, and a functioning experimental expert weapon direction system. An overview of the current weapon direction system and associated missile employment operation is provided as a basis for discussing timing and coordination requirements. The development and test of an experimental expert support system using sumulated missile engagements is reviewed in terms of language structures, incorporation of expert procedural knowledge, and system modeling. Preliminary results from testing the experimental expert system at the engagement system land based test site in Laurel, Maryland are reported, and future plans are summarized.
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