Power loss analysis of grid connection photovoltaic systems

This paper presents power loss analysis of grid-connection PV systems, based on the loss factors of double line-frequency voltage ripple, fast irradiance variation, fast dc load variation, non-uniform solar cell characteristic, and limited operating voltage range. These loss factors will result in power deviation from the maximum power points (MPP). In the power loss analysis, both single-stage and two-stage grid connection PV systems are considered. The effects of these loss factors on two-stage grid-connection PV systems are insignificant due to an additional maximum power point tracker (MPPT), but it will reduce the system efficiency typically about 3%. The power loss caused by these loss factors in single-stage grid-connection PV systems is also around 3%; that is, a single-stage grid-connection PV system has the merits of saving components and reducing cost, while does not scarify overall system efficiency. Simulation results with a MATLAB software package are presented to confirm the analysis.