High concentration photovoltaic system (HCPV) combines high-efficiency concentrating photovoltaic cells with concentrator utilization, which has high efficiency. Aiming at the characteristics of high efficiency and good temperature characteristics of three junction focused InGaP / lngaas / Ge laminated photovoltaic cells, a mathematical model of electrical characteristics of three junction focused InGaP / lngaas / Ge laminated photovoltaic cells is established based on the equivalent circuit of single diode model, The open circuit voltage and cell efficiency of three junction GaAs photovoltaic cells are theoretically analyzed and calculated, and compared with the experimental results. The results show that the open circuit voltage and cell efficiency of three junction GaAs photovoltaic cells increase with the increase of concentration ratio and decrease with the increase of cell temperature. The experimental results are compared with the theoretical calculation. At the same battery temperature, the errors of open circuit voltage and battery efficiency are 2.04% and 8.4% respectively. The mathematical model of three junction GaAs photovoltaic cell provides a theoretical basis for studying its electrical performance, and can be used to analyze and discuss the influence of relevant parameters on the performance of high-power concentrating photovoltaic system.
At present, the experimental research on the performance of GaAs cells in high power concentrating system is mainly based on indoor simulated light source conditions, and there is relatively little research on outdoor conditions. A small Fresnel concentrating photovoltaic system is designed and built, and the system structure and working principle are introduced, The experimental results show that when the geometric focusing ratio of Fresnel concentrating photovoltaic system is 500 and the solar radiation intensity reaches the peak value of 948 w / m2 at 13:00, the short-circuit current of the single-chip cell after focusing is amplified 253 times, the open circuit voltage is increased by 0.34 V, the temperature of the battery back plate is 86.6 ℃, and the short-circuit current reaches the peak at this time, The open circuit voltage did not reach the peak value due to the increase of chip temperature. The peak value appeared at 10:30, and the peak value was 2.85 V, which was 0.03 V higher than the open circuit voltage when the solar radiation intensity reached the peak value. At this time, the battery backplane temperature was 74.4 ℃