Operation Optimization for Performance Improvement of PV/converter Systems

Photovoltaic/converter modular system with cascaded configuration is always preferred for achieving relatively high voltage output, individual module MPPT and decreasing mismatching losses. However, the limit of conversion ratio brings about the issue that not all modules can operate at their maximum power points (MPP) under serious mismatching conditions. This paper mainly discussed this problem and proposed and approach that evaluated whether a low irradiation module should be bypassed or not. Simulations of representative cases were investigated and the results showed that limit of conversion ratio together with the lowest irradiation module´s current restrained the operation current of other modules, which caused great losses. Further researches also demonstrated that such phenomenon could be settled by bypassing the low irradiation module.