Total simulator for concentrator photovoltaic modules using ray-trace and circuit simulators

Total simulator for concentrator photovoltaic (CPV) modules was developed using ray-trace and circuit simulators. By using this total simulator, we can calculate the operating characteristics of CPV modules composed of optical system and InGaP/InGaAs/Ge triple-junction solar cell. We used a ray-trace simulator ZEMAX for ray-trace simulation. A typical flat Fresnel lens was adopted as a first lens and quadrangular prismoid prisms with and without convex array were adopted as a secondary lens. The generated photocurrent was obtained from ray-trace simulation and spectral response of InGaP/InGaAs/Ge triple-junction solar cell. By using the homogenizer with the convex array, the uniformity of concentrated light was improved. A multi-unit equivalent circuit model for InGaP/InGaAs/Ge triple-junction solar cell can carry out calculations considering the in-plane intensity distribution of the concentrated light. From the results of ray-trace simulation, we could know the intensity distribution of photocurrent from each sub-cell. By using the ray-trace simulation and circuit simulation, the operating characteristics of CPV modules were calculated totally. It was observed that the FF could be improved from 0.814 to 0.893 by adopting the homogenizer with the convex array. We can use the total simulator for the evaluation and optimization of CPV cells and modules.