Design of Photovoltaic Panel-Light-Emitting Diode Spotlight and Its Performance Analysis in Tunnel Buildings

Abstract

According to the adaptive characteristics of the entrance and exit sections of tunnel buildings with the intensity of external sunlight, the cost of traditional photovoltaic panel (PV)-light-emitting diode (LED) lighting system increases due to battery. Combined with the structure of sunshine conveyor, a new PV-LED spotlight is proposed. The lighting device uses PV module as the power supply to directly drive the LED light source, which can make the brightness of the tunnel synchronized with the sunlight intensity, avoid the problem that it cannot work stably due to its weather changes, and further save the cost without battery. The main control chip adopts STC12C5A60S2 and supports multiple 10-bits precision A/D conversion channels. It can process the output signal of the light intensity detection circuit and set a threshold circuit to judge the intensity of sunlight, further control the working state of LED lighting device. The LED display module adopts 12864 liquid crystal display (LCD) with built-in T6963C driver to display five kinds of data, including the output voltage of light intensity detection circuit and the corresponding voltage value of four threshold circuits. The circuit resistance can be adjusted to change the light output voltage threshold required by the tunnel. In the test, the PV-LED lighting device is erected in the tunnel building. Compared with the traditional PV-LED lighting device and the new PV-LED spotlight designed, the new PV-LED lighting device in the morning and evening can further improve the efficiency of solar power generation. Meanwhile, the PV plate plane of the designed lighting device is perpendicular to the plane where the sunlight shines. The spectral irradiance and full band spectral irradiance of the lighting device in six bands was calculated and found that the percentage of spectral irradiance in different bands is close to the percentage requirement under AM1.5.