MBB High Efficiency Module Technology and Development Trends-Yingli

MBB Module Technology and Development Trends Ni Jianxiong Vice GM of Technology Center August 2,2018 Changzhou Contents MBB technology development trend MBB module power optimization MBB + half-cut module power optimization MBB module advantages MBB technology development trend Theory Optical gain MBB used round ribbon can reduce the shading area, effectively reflect the light onto the cell, improve the module short-circuit current, and enhance the optical utilization of the ribbon area from less than 5% to over 40%. The width of the busbar is finer and the pitch is narrower, which can shorten the current transmission distance of fingers; the half-cut cell is connected by series and parallel, thereby reducing the resistance loss; the gap area of cells is increased, and the power of the module can be increased by more than 10w. Electrical gain Conventional cell MBB cell Conventional cell MBB cell MBB +half-cut cell MBB module power optimization Theoretical simulation The total area of the busbars is constant, and the number of busbars is changed As the number of busbars increases, the power of the cell varies greatly in the range of 3BB to 10BB, and the power increases slowly when 10BB. As the number of busbars increases, the series resistance of the cell gradually decreases. MBB module power optimization Theoretical simulation- P-type multi-si cell module Module power improved--theoretical Cell Module Theoretical simulations show that as the number of cell busbars increases, cell efficiency increases. The 12BB cell is 0.448% more efficient than the conventional 5BB cell, and the estimated 60-pcs module power (electrical) is increased by 4W. Theoretical simulations show that as the number of cell busbars increases, module power increases. The 12BB module has a power increased of 8.044W over conventional 5BB module. Cell efficiency improved--theoretical MBB module power optimization Practically- P-type multi-si Module Power increased Compared with the 5BB and 12BB multi-si modules under the same cell source, the power gain of the 12BB module is 8.173W. And the theoretical calculation result is 8.044W. Practical production and simulation are not much different. MBB module power optimization Theoretical simulation- N-type mono-si cell module Cell efficiency improved--theoretical Module power improved--theoretical Cell Module Theoretical simulations show that as the number of cell busbars increases, cell efficiency increases. The 12BB mono N-type cell is 0.5% more efficient than the conventional 5BB cell. Theoretical simulations show that as the number of cell busbars increases, module power increases. The 12BB mono N-type module has a power increased of 10.858W over conventional 5BB module. MBB module power optimization Practically- N-type mono-si Cell  Yingli 12BB design, through the optimization of fingers width and screen parameters, reduces the paste consumption by 30% and effectively reduces cell cost. From the experimental comparison with the 5BB, the 12BB can improve the Uoc and Jsc of the cell, and the FF increased is the most significant. The average conversion efficiency of the cell is increased by 0.5%, and the absolute value is 22%. MBB module power optimization Practically- N-type mono-si Module 5BB 12BB Power increased Compared with the 5BB and 12BB N-type mono-si modules under the same cell source, the power gain of the 12BB module is 10.007W. And the theoretical calculation result is 10.795W. Practical production and simulation are not much different. MBB module power optimization Simulation relevant parameters Different round ribbon diameters, different busbars number For the power of the MBB module, there is a balance point between the number of busbars and the wire height. The number of busbars increases, and the smaller of the wire height, the better the power of the module is improved; A 12BB design allows for better module power output. MBB module power optimization Simulation relevant parameters Change the bottom angle and width of the triangular ribbon, the number of busbars is constant Module power changes with different bottom angles of 7BB triangular ribbon Module power changes with 7BB triangular ribbon width For MBB triangular ribbon module, the optical gain is best when the triangular bottom angle is around 65。 . For the 7BB triangular ribbon module, the power gain is not significant after the ribbon width is up to 600μm. MBB + half-cut module power optimization Theoretical simulation Conventional ribbon Triangular ribbon Round ribbon Full-cell Half-cell Full-cell Full-cell Half-cell Half-cell The conventional ribbon 5BB module and the triangular ribbon 7BB module, the half cell is more than 6W higher than the full cell module, and the efficiency loss caused by the cutting damage of the half-cell is neglected in the simulation. For a 12BB half-cut module, similar to its corresponding full- cell module, there is an optimum value for the ribbon width, and the optimum value of the half-cut module is lower than that of the full cell module. MBB + half-cut module power optimization Experimental verification Simulation: 7BB Flat ribbon VS 5BB Flat ribbon Ribbon 5BB Flat ribbon 7BB Flat ribbon Thickened EVA Conventional EVA Times of test 7BB half-cut+ triangular ribbon (front side: triangular ribbon width of 0.6mm; rear side: flat ribbon, 0.2mmX2.0mm) 7BB full cell+ flat ribbon (front side: flat ribbon, 0.25mmX0.6mm; rear side: flat ribbon, 0.2mmX2.0mm) Average Average MBB module advantages Advantages Conventional cell MBB cell Reduce the risk of cracks and finger breakage Lower NMOT and hot spot risk Reduce shading Outdoor detection result shows, the operating temperature of half-cut cell modules is 0.5。 C-1。 C lower than conventional full-cell modules， and the hot spot temperature is 20。 C lower. The module circuit adopts series- parallel design, the voltage and current output are almost the same as the full cell, and it has lower power loss in the case of shading. MBB module advantages Simulation of module IAM By simulating the module IAM and comparing several different types of ribbon modules, under the ideal geometric model, the photocurrent of the 12BB module is higher than the conventional 5BB module in a larger angle range, and the IAM values of the two are similar; 7BB cell module, due to the application of the triangular ribbon, the optical gain effect is significantly reduced when the incident light is at a certain angle, resulting in a sudden change of the IAM curve at this angle. Vertical installation MBB module advantages Simulation of module IAM Horizontal installation By simulating the module IAM and comparing several different types of ribbon modules, under the ideal geometric model, the photocurrent of the 12BB module and 7BB triangular ribbon module are higher than the conventional 5BB module in a larger angle range, and the IAM values of the three are similar. MBB module advantages High power generation Power generation gain: 0.5% Summary Compared with the 5BB cell module, the power of the 12BB multi module is increased by 2.96%, and the power of the 12BB N-type mono module is increased by 3.3%; Adopted MBB + half-cut design, optimized ribbon size and number of busbars, etc., MBB + half-cut module power is increased by more than 5.3% relative to 5BB cell module; MBB/half-cut PV modules offer higher product reliability and reduce the risk of cracks and finger breakage. Simulating different MBB module designs for outdoor performance, round ribbon MBB module and conventional module, whether horizontal or vertical installation, IAM performance is equivalent, only 7BB triangular ribbon in the 50 ° zenith angle direction IAM performance is slightly worse, but the overall simulated power generation results vary little. Thank you！