A simplified simulation method was described for charactering mismatching photovoltaic performance integrated with bypass and string diodes, which are configured additionally compared with the tradition design for avoiding deterioration to modules in series or in parallel connection. The Newton-Raphson method was adopted for numerical simulations, with some computation problem discussed for fast convergence. It was proven to be suitable and effective when model validation coinciding with manufacturer specification. Furthermore, maximal power point (MPP) peak positions were reviewed roundly via simulations of the total characteristic curves. Multi-power peaks with multi-diodes installed were also investigated. The proposed method can be benefit for better comprehension on the physical circuit and provides greater program expansibility, and such simulation researches should be applicable for manufacturer to evaluate the configuration of photovoltaic module. © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.