电阻焊光伏组件接线盒的可靠性研究

Research on the Reliability of Resistance Welding Photovoltaic Module Junction Boxes

由于光伏组件额定电流越来越高,与之配套的接线盒额定电流也越来越大,对接线盒与汇流条焊接牢固程度的要求越来越高,而现有接线盒大都采用哈巴焊模式,容易出现欠焊、虚焊、脱焊等系列焊接不良情况,从而导致接线盒接触电阻变大,功率损耗增加,严重的可能会导致组件着火、烧毁的情况,给电站的运维带来严重的安全隐患。本文通过对电阻焊接线盒的可靠性研究,提出了一种接线盒焊接用电阻焊模式,有效的解决了接线盒与组件汇流条焊接不良的情况;通过温升测试发现电阻焊的二极管结温明显低于哈巴焊,对焊接端面解剖发现电阻焊可将汇流条与焊盘铜基材完全融化形成一个统一体,解决了哈巴焊汇流条与焊盘之间存在明显分界的问题;在电阻焊接线盒经过TC200加严测试后,接线盒与汇流条的接触电阻从0.270 mΩ变为0.264 mΩ,基本没有变化,说明电阻焊可靠性极高,为后续大电流组件的安全应用提供了一定的参考价值。

Due to the increasing rated current of photovoltaic modules and the matching junction boxes,the requirements for the firmness of the welding between the junction boxes and busbars are becoming higher.However,most existing junction boxes adopt the Habba welding mode,which is prone to a series of welding defects such as under soldering,virtual soldering,and desoldering,resulting in an increase in contact resistance and power loss of the junction boxes.In severe cases,it may lead to module ignition and burning,posing serious safety hazards to the operation and maintenance of the power station.This article proposes a resistance welding mode for junction box welding by studying the reliability of resistance welding junction boxes,which effectively solves the problem of poor welding between junction boxes and component busbars;Through temperature rise testing,it was found that the junction temperature of the diode in resistance welding is significantly lower than that in Habba welding.Upon dissection of the welding end face,it was found that resistance welding can completely melt the busbar and the copper substrate of the solder pad into a unified entity,solving the problem of obvious boundary between the busbar and the solder pad in Habba welding;After undergoing strict TC200 testing on the resistance welding junction box,the contact resistance between the junction box and the busbar increased from 0.270 mΩto 0.264 mΩ,with little change.This indicates that the of resistance welding is extremely high,providing a certain reference value for the safe application of high current components in the future.