Research of Main Transformer Planning and Load Transfer in Mass Rapid Transit Power Systems with Color Petri Net

• Main Authors: Syuan Yi Lin, 林軒儀
• Other Authors: Jaw Shyang Wu
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/36205518277761163683

碩士 === 國立高雄應用科技大學 === 電機工程系碩士班 === 92 === Main-transformer installation planning in mass rapid transit(MRT) systems is a multi-objective issue which involves the determe the capacity of the transformers, the years and the substations to install the transformers. In this thesis,color Petri Net(CPN) model is proposed to create the rule-based inference network for main-transformer installation planning and another CPN model for load transfer in case of faults occurred in main transformer. Since the number of main-transformers installed in a bulk-supply substation(BSS) of MRT system is usually one or two banks, this work presents two schemes for the installation planning: the dispersed scheme and the clustered scheme. The dispersed scheme performs better voltage profiles and less loss reductions. On the other hand, the clustered scheme provides less number of installations and hence performs more cost-effective. Results of these two schemes are discussed and verified by load flow analysis. It is substantially important to provide reliable power system in MRT systems. In case of faults happened in main-transformers, switching operation should be performed among BSSs to find the proper paths to transfer the tripped load to the backup transformers. In this thesis, a color Petri-net model is proposed for the load transfer to present the options of switching operations if a main-transformer is out-of-service due to fault or maintenance.to Load flow analysis is also performed to verify the results of the switching operations. To demonstrate the effectiveness of the proposed CPN models, the Taipei MRT network is selected for computer simulation. It is found that the proposed methodology provides the optinal expansion planning of the transfermer capacity, the installation site, and the year to install the transformers simultaneously. It is interesting that by comparing to the current installation in Taipei MRT system, the number of transformer banks can be reduced by consider reasonable back-up capacity and moreover the number of BSSs can be reduced too.