Experimental Analysis of Effects of Connection Type on PV System Performance

Abstract

This paper mainly focuses on experimental performance analysis of solar modules under different irradiance values. Also effects of interconnection types and bypass diode application on module output characteristics under variable shading patterns are analyzed. The mentioned analyses are based on and supported by real-time measurement data and the results confirm the direct relationship between the power generation by solar modules and the incident solar irradiance. According to the results, although higher voltage values are obtained, series strings of solar cells/modules, without bypass diodes, show a higher sensitivity to shading effects and string output power is subjected to higher amounts of reduction compared with the parallel connection conditions. On the other hand, parallel connected solar cells/modules provide higher values of generated current amounts while the output voltages are equivalent to that of each individual cell/module. Experimental results also show that application of bypass diodes in series connected module strings has a great improving effect on power production by the string. The significance of the results arises during design and planning procedures of solar energy systems, where detailed knowledge of system characteristics under different shading patterns creates the opportunity to take the required measures and obtain optimum system performance.