A novel rotational symmetry (RS) connection approach for dense-array concentrator photovoltaic (DA-CPV) modules

Abstract

Dense array concentrator photovoltaic (DA-CPV) system is facing large mismatch losses due to the highly concentrated non-uniform radiation. In this paper, a novel rotational symmetry (RS) connection approach with two examples is proposed to reduce mismatch losses. The output performances of the two RS connections are compared with that of four conventional connections by using a two-stage simulation method. The results indicate that under different illumination distributions and CPV cell’s series resistances, the RS connection approach can dramatically reduce power losses. The proposed dichotomic rotational symmetry (DRS) and quartered rotational symmetry (QRS) connections can significantly improve the output characteristics of DA-CPV modules. Compared with the conventional series-parallel (SP) connections, the DRS and QRS connections can improve the conversion efficiency by at most 48% and 64.3%, respectively. Meanwhile, the QRS connection exhibits smoother I-V and P-V curves, reducing the difficulty of system's maximum power point tracking (MPPT) and improving the stability of output performance with varying Gaussian illuminations. When considering the Joule heat losses generated from the series resistance of CPV cells, the RS connections can also achieve much higher conversion efficiencies than other conventional configurations.