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Title:	Optimal network reconfiguration and DSTATCOM placement for voltage sag mitigation using gravitational search algorithm
Authors:	Nesrallh Salman Khelef (P44068)
Supervisor:	Azah Mohamed, Prof. Dr.
Keywords:	Electric power systems -- Control Power resources Electric power system stability Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	28-Jun-2012
Description:	Voltage sag is considered as one of the most common power quality problem which may cause sensitive equipment to malfunction and process interruption which leads to poor system reliability. Many efforts have been made to mitigate voltage sags by using custom power devices such as uninterruptible power supply, dynamic voltage restorer, distribution static compensator (DSTATCOM) and unified power quality compensator. However, to enhance utility side efforts in voltage sag mitigation, distribution network reconfiguration which is commonly used for the purpose of network loss reduction is considered in this research work. The objective of this research is to determine optimal network reconfiguration and optimal DSTATCOM placement for voltage sag mitigation and reliability improvement. In the proposed integrated method, initially, optimal network reconfiguration which uses feeder transfer switches in power distribution systems is applied to reinforce the system voltage profile during voltage sag and then followed by optimal placement of the DSTATCOM to obtain complete mitigation of voltage sag. The binary version of the gravitational search algorithm (GSA) is used as the heuristic optimization tool to determine optimal solutions of the network reconfiguration and DSTATCOM problems. A comparative study was made to evaluate the effectiveness of the GSA by comparing it with other established heuristic optimization techniques such genetic algorithm (GA) and particle swarm optimization (PSO). A new encoding and decoding technique was developed to maintain radial structure of distribution network as well as to establish the DSTATCOM location. For illustrating the effectiveness of the developed optimal network reconfiguration and DSTACOM placement methods in improving system reliability, an assessment was performed using the well-known reliability indices, namely, SAIFI, ASIFI and MAIFI. To implement the developed optimization techniques for distribution system analysis in an open source environment, a Matlab based software package, named as Heuristic Optimization Application to Distribution System (HOADS) has been developed. HOADS is used for solving power flow, short circuit analysis, reliability assessment, optimal network reconfiguration and DSTATCOM placement based on GSA, GA and PSO. To validate the accuracy of the proposed integrated optimal network reconfiguration and DSTATCOM placement, the practical 47 bus test distribution system was used. The test results show that the integrated optimal network reconfiguration and DSTATCOM placement method gives significant improvement in voltage sag mitigation of distribution systems in which the total number of healthy buses with voltage -0.9 pu, is improved from 18 to 33 and the reliability index is improved with SAIFI from 17.65 to 14.01.,Certification of Master's / Doctoral Thesis" is not available
Pages:	199
Call Number:	TK1010.K486 2012 3 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

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