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Flow Controller (flow + controller)
Kinds of Flow Controller Selected AbstractsDynamic performance analysis of novel unified power flow controller with computer simulation and scaled-model experimentEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2008Byung M. Han Abstract This paper describes dynamic performance analysis of Unified Power Flow Controller (UPFC) composed of cascaded H-bridge and single-phase multi-winding transformers for isolation. The operational characteristic was analyzed through simulations with PSCAD/EMTDC, and experimental works with a scaled model. The UPFC proposed in this paper can be directly connected to the transmission line without series injection transformers. It has flexibility to expand the operation voltage by increasing the number of H-bridges. Copyright © 2007 John Wiley & Sons, Ltd. [source] Application of differential evolution algorithm for optimal location and parameters setting of UPFC considering power system securityEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 7 2009Husam I. Shaheen Abstract Unified power flow controller (UPFC) is one of the most effective flexible AC transmission systems (FACTS) devices for enhancing power system security. However, to what extent the performance of UPFC can be brought out, it highly depends upon the location and parameters setting of this device in the system. This paper presents an approach based on evolutionary algorithms (EAs) techniques to find out the optimal placement and settings of UPFC for enhancing power system security under single line contingencies (N-1 contingency). Firstly, we perform a contingency analysis and ranking process to determine the most severe line outage contingencies considering line overloads and bus voltage limit violations as a performance index. Secondly, we apply an evolutionary optimization technique, namely: differential evolution (DE) to find out the optimal location and parameters setting of UPFC under the determined contingency scenarios. To verify our proposed approach and for comparison purposes, we perform simulations on an IEEE 14-bus and an IEEE 30-bus power systems. The results we have obtained indicate that DE is an easy to use, fast, and robust optimization technique compared with genetic algorithm (GA). Installing UPFC in the optimal location determined by DE can significantly enhance the security of power system by eliminating or minimizing the overloaded lines and the bus voltage limit violations. Copyright © 2008 John Wiley & Sons, Ltd. [source] Dynamic performance analysis of novel unified power flow controller with computer simulation and scaled-model experimentEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2008Byung M. Han Abstract This paper describes dynamic performance analysis of Unified Power Flow Controller (UPFC) composed of cascaded H-bridge and single-phase multi-winding transformers for isolation. The operational characteristic was analyzed through simulations with PSCAD/EMTDC, and experimental works with a scaled model. The UPFC proposed in this paper can be directly connected to the transmission line without series injection transformers. It has flexibility to expand the operation voltage by increasing the number of H-bridges. Copyright © 2007 John Wiley & Sons, Ltd. [source] Linear quadratic optimal sliding mode flow control for connection-oriented communication networksINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 4 2009Przemys, aw Ignaciuk Abstract In this paper, a new sliding mode flow controller for multi-source connection-oriented communication networks is proposed. The networks are modelled as discrete time, nth-order systems. On the basis of the system state space description, novel sliding mode controllers with linear quadratic (LQ) optimal and sub-optimal switching planes are designed. The control law derivation focuses on the minimization of the LQ cost functional and solving the resultant matrix Riccati equation. Closed-loop system stability is demonstrated, and conditions for no data loss and full bottleneck link bandwidth utilization in the network are presented and strictly proved. To the best of our knowledge, this paper presents the first attempt to design a discrete time sliding mode flow control algorithm for connection-oriented communication networks. Copyright © 2008 John Wiley & Sons, Ltd. [source] A direct control scheme based on recurrent fuzzy neural networks for the UPFC series branch,ASIAN JOURNAL OF CONTROL, Issue 6 2009Tsao-Tsung Ma Abstract In this paper, a new control scheme using recurrent fuzzy neural controllers is proposed for the series branch of the unified power flow controller (UPFC) to improve the dynamic performance of real-time power flow control functions with the aim of reducing the inevitable interaction between the real and reactive power flow control parameters. To simplify the theoretical analysis of the coupled dynamics within the UPFC and the controlled power system, the three phase description of a two-bus test power system embedded with a UPFC is transformed into d,q components based on a synchronously rotating reference frame. For control systems with inherent nonlinear coupling features, a feed-forward control scheme based on fuzzy neural controllers is developed to realize the decoupling control objectives. Based on the simulation results, the proposed control scheme is able to overcome the drawbacks of the traditional power flow controllers designed on small disturbance linearizing methods. Comprehensive simulation results on the EMTDC/PSCAD and MATLAB programs are presented and discussed to verify the effectiveness of the proposed control scheme. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] |