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Research On MPPT Based On Improved TLBO And Distributed Topological Structure Of Photovoltaic Array

Posted on:2015-11-15Degree:MasterType:Thesis
Country:ChinaCandidate:Z WuFull Text:PDF
GTID:2272330422472596Subject:Control Science and Engineering
Abstract/Summary:PDF Full Text Request
Photovoltaic array is the core of the energy-transformation in photovoltaic powergeneration system. When the cell is under non-uniform illumination, the outputpower-voltage curve of the PV system will show a multi-peak characteristic. So thetraditional tracing method of the maximum power point would fail. What’s more,photovoltaic cell will get a series of problems caused by mismatch on the overshadowcondition. The usual solution is using the bypass diodes to protect the solar panels,however, this method lead to a substantial drop of power generation efficiency. In oneword, a more suitable maximum power point tracking algorithm and building up a newtopological structure of photovoltaic array and its control method are the significancefor improving the generating efficiency and the system stability.Based on the domestic and foreign literature, this thesis modified theTeaching-Learning-Based Optimization (MTLBO) by introducing the Self-PreviewPhase and Self-Repair Phase. The contrastive analysis showed that the new algorithmgot a better performance at convergence rate and optimizing ability. This algorithm canfind the maximum power point accurately when used in overshadow photovoltaic powergeneration system. What’s more, this thesis put forward a distributed PV arraytopological structure based on the DC/DC micro-optimizer. The structure provided aoptimizer constituted by Boost circuit for every photovoltaic cell instead ofconventional back diode. So it can realize the panel-level maximum power pointtracking. The contrast experiment showed that the topological structure can effectivelyreduce the influence to other batteries on the same spur track. At the same time it candramatically improve the generating efficiency of the system and guarantee the safety ofPV array on every kind of overshadow condition,This thesis established a simulation model according to the working principle ofsolar cells and did a dynamic overshadow experiment by building up a distributedindependent photovoltaic power generation system which using MTLBO. The resultshowed that the algorithm and the topological structure from this thesis are feasible andeffective.
Keywords/Search Tags:Partially Shaded, MPPT, Distributed Topological Structure, TLBO
PDF Full Text Request
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