Application of solar energy combined with LED lights

Solar energy, as a clean new energy source, has always been strongly supported by the state. It was first applied to lighting fixtures for civilian use. Solar LED lighting products are a new generation of green and environmentally friendly lighting products. Its main components include solar photovoltaic cells and semiconductor lighting sources. . Because the LED solar lamp integrates the solar LED lighting system with the advantages of solar photovoltaic power generation and LED solid-state lighting, it realizes the perfect combination of a new generation of energy and a new light source. However, in the design of solar lighting lamps, many factors are involved in the light source, solar battery system, and battery charging and discharging control. Problems in any of these links will cause product defects.

The key to the perfect combination of solar photovoltaic power generation technology and LED lighting is that the two are both direct current, low voltage and compatible with each other. Therefore, the combination of the two does not need to convert the direct current generated by the solar cell into alternating current, thus greatly improving the efficiency of the entire lighting system. At the same time, with the help of grid-connected technology or the use of battery charging and discharging energy, its advantages are more obvious.

When designing and using it, it should be noted that the characteristics of LEDs are close to voltage stabilized diodes, the working voltage changes, V, and the working current may change about mA. For safety, a series current-limiting resistor is used under normal circumstances, and the huge energy loss is not suitable for solar lawn lamps, and the brightness of the LED varies with the operating voltage. It is a good way to use a booster circuit, and a simple constant current circuit can also be used. In short, the current must be automatically limited, otherwise the LED will be damaged. Generally, the peak power of the LED is ~mA, and the reverse voltage is about V. Be careful not to exceed this limit, especially when the solar battery is reversely connected or the battery is empty, and the peak voltage of the boost circuit is too high, it is likely to exceed this limit and damage the LED. LED temperature characteristics are not good, the temperature rises, the luminous flux declines, it is necessary to pay attention to the use in summer. The working voltage is highly discrete, and the working voltage of the same model and the same batch of LEDs has a certain difference, so it is not suitable to be used in parallel. Must be used in parallel, and current sharing should be considered. Solar lights often require high maintenance time for continuous cloudy and rainy days, which increases the cost of the system. We reduce the number of LEDs or energy-saving lamps connected when the battery voltage drops in continuous rainy days, or reduce the light-emitting time of solar lamps every day, which reduces the cost of the system. Flickering and dimming, gradually brightening and dimming is a good way to save energy. On the one hand, it can increase the illumination effect of solar lawn lights, and on the other hand, it can control the average output current of the battery by changing the flicker duty cycle to extend the system working time, or under the same conditions Down, can reduce costs. The switching speed of the tri-color primary energy-saving lamp even determines the service life of the solar lamp. When the tri-color primary energy-saving lamp is started, it has up to ~ times the starting current, and the system will cause a large voltage when it is subjected to such a large current. When it falls, the solar light cannot be started or restarted repeatedly, resulting in final damage. Currently, solar cells cannot be used for main road lighting. The lighting of main roads of highways has statutory illuminance requirements. As far as the current conversion efficiency and price of solar cells are concerned, this requirement cannot be met. However, in the near future, with the improvement of technical standards in various aspects, solar cells will definitely be used in the lighting of main highways. Regarding energy storage capacitors, the service life of solar cells is more than one year, and the service life of ordinary storage batteries is ~ years, so storage batteries are the weakest link in the solar power system. Energy storage capacitors can solve this problem to a certain extent. The service life of the energy storage capacitor can reach more than one year, and the control circuit is simple, but the expensive price limits its application. At present, it is only applied to some traffic lights and decorative lights. With the improvement of technical standards and the decline of product prices, it will be the most promising ideal energy storage component for solar cells.

With the continuous improvement of energy conversion efficiency, it is believed that the service life of solar lamps can reach more than 10,000 hours in the near future. This is the real green lighting. For outdoor road lighting, led solar street lights are bound to become the leading products for sustainable development.