The Influence And Countermeasures Of Micro-Cracks Defect In Crystalline Silicon Solar Module

Photovoltaic(PV)power generation does not rely on fossil fuels,environmental friendly.In recent years as the crystalline silicon PV module manufacturing costs decrease,the domestic scale expanded rapidly,adds new power generating capacity of tens of millions of years.In order to ensure the income of PV power generation system for long-term stability,the quality of the PV modules is becoming more and more attention.The problem of solar cell with micro-crack in PV modules is one of the focus of attention.This paper aim to find out the failure mode of solar cell micro-crack in PV modules and the quantitative relationship between solar cell micro-crack and the power output of the PV module,classify the solar cell micro-crack types,and assess the risk level each of them.The main ideas of the paper are listed as following.1)The failure mode of solar cell micro-crack in PV modules is that the cracks rupturing the finger of solar cell,hindering the collection and gathering of light generated current,and increasing the series resistance of the fragments or isolating the fragments from the main circuit.2)The fragments formed by micro-crack can be classified into three types.In the first type,the fingers in the area can collect and gather the light generated current normally.In the second type,the micro-cracks make the fragments with high series resistance.And in the last type,the micro-cracks isolate the fragments from the main circuit.3)For long term aging,especially high and low temperature alternating,the PV modules with solar cell micro-crack will reduce the power output due to the interconnector desoldering the solar cell.4)When the isolated area accounts for 5% of a whole cell,there isn't any effect of the power output of PV modules because of micro-crack.The innovation of this paper are listed as flowing.1)Track solar cell micro-cracks evolvement process in a single PV module by EL examining,and measure the power output of the module with different solar cell micro-cracks which produced by practically destructing the modules such as pressing,striking,treading and falling down it.2)An experiment scheme is designed.Finding out the quantitative relationship between the isolated area caused by micro-crack and the power output of the PV module by cutting away a part of a solar cell in one cell of a module and measuring the power output of the module.3)Classify the type of solar cell micro-cracks,and assess the risk level each of them.