Study On The Power Loss Of Photovoltaic Module During Encapsulation Process

The presence of various factors during the encapsulation process will inevitably effectuate power output loss of photovoltaic(PV)module.Researching these factors is benifiacal to achieve power loss reduction and cost reduction,while simultaneously increase product market competitiveness.However,due to the complexity and the multitude of several interacting factors involved,understanding of the loss mechanism is not systematic and comprehensive.This thesis aims to systemically study factors on power loss of photovoltaic module during encapsulation loss.Firstly,the encapsulation bill of material(BOM)is set apart for analyses.Eight factors includy Cell,glass,ethylene vinyl acetate(EVA),backsheet,soldering ribbon,soldering busbar and junction box were analysed parameters belind to discuss their influences and mechanism.Secondly,physical properties of BOM such as transmittance of glass and EVA,the reflectivity of backsheet,the specification of soldering ribbon as well as other design features such as the module layout and the cell mismatch factors were investigated to compare their different contribution towards module performance.Results show that different parameter has different mechanisms on the module performance.Among the contribution,the glass coating utilizes increased light transmittance to excite increased amount of electron-hole pairs in the cells,which gained 1.88%increased power output compared with that of the glass without coating.The half-cut cells reduce the working current of the module and thus reducing the loss on the soldering resistance,a relative gain of 2.49%power output when compared to the full cells.White backsheet improves the power output by 2.13%compared to black backsheet by increasing secondary reflection of incident light.Thirdly,a Matlab simulation model is constructed to quantify the involving factors and mechanisms.Results show that the encapsulation glass and EVA as well as backsheet have positive roles about 2.35%and 1.91%increase respectively,for module power output.For the magnitude order of module performance is the soldering resistance>the busbar ribbon resistance>the cells mismatch>the junction box resistance>the soldering ribbon shading>the contact resistance The simulation has explored a path to reduce cell mismatch effect by rearrangeing panel layout,and also evaluated the upper limit of all method.The overall simulated module performance shows that it is expected to improve the ratio of theoretical sum of cell power and actual module output power(CTM),by 4.2%.