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LED lighting has a landmark in the field of lighting. With the ever-increasing world demand for energy consumption, the storage of major energy resources in the contemporary world, such as oil, natural gas, and coal, is gradually decreasing. According to current mining speeds, oil and natural gas have only 40 years and 60 years of recoverable reserves, respectively. The search for the use of new and renewable energy sources and the development of energy-efficient technologies have received widespread attention worldwide. Solar photovoltaic LED lighting is a typical application of new energy and energy-saving technologies. Solar photovoltaic power generation converts solar energy in nature into electricity and provides it to LED light sources. Due to the low voltage, energy saving and long-term characteristics of LED light sources, the application of solar LED lighting systems will achieve high energy utilization efficiency, work reliability, and practical ＆#118alue. Therefore, the research on the control technology of solar photovoltaic power generation lighting system has received various attention.

LED lighting energy-saving principle

Solar photovoltaic LED lighting system consists of energy-efficient solar photovoltaic LED lighting system including solar battery pack, DC-DC converter, maximum power tracking MPPT control, battery storage and LED lighting control, LED light source And other stage lighting.

The working principle of the solar photovoltaic power generation lighting system is: in the period of sunlight, the solar battery group converts the collected solar energy into electric energy; under the control of the control system, the maximum power tracking (MPPT) method of the solar photovoltaic battery is adopted. Electrical energy is stored in the battery pack; when the LED lighting system needs power supply, it provides safe and efficient voltage and current to the LED lighting source. Make the LED lighting system work energy-efficiently and provide clean and environmentally-friendly green lighting for people's work and life.

Solar photovoltaic power generation Solar photovoltaic cell power generation is one of the main ways to use solar energy.

The principle of solar photovoltaic cell power generation is the photovoltaic effect. For crystalline silicon solar cells, the typical ＆#118alue of the open circuit voltage is 0.5 0.6 V. The more electrons and hole pairs generated by light irradiation in the interface layer, the greater the current formed. The more light energy absorbed by the interface layer, the greater the same current. Currently used and researched solar cells are mainly silicon solar cells, compound semiconductor cells, and dye-sensitized solar cells. Silicon solar cells are currently the mainstream of solar photovoltaic cells. In silicon solar cells, the photoelectric conversion efficiency of monocrystalline silicon solar cells is the highest, the laboratory conversion efficiency is over 24%, and the efficiency of monocrystalline silicon solar cells produced on an industrial scale reaches 18%. the above. Thin-film solar cells have been greatly developed in recent years. New solar cells such as polysilicon/crystalline silicon/microcrystalline silicon thin-film solar cells have also been industrialized, and the highest conversion efficiency has reached over 16%. In recent years, research on compound semiconductor solar cells such as CIS, CIGS thin-film solar cells, and GaAs solar cells has also made practical progress. Dye-sensitized TiO solar cells have also achieved remarkable results.

There is a nonlinearity and variability between the output voltage and the current of the solar cell. There is a maximum power output point and a voltage-sum current corresponding to the maximum power point in a specific environment. When the environment changes, the output characteristics of solar cells also change. The characteristic curves of the output voltage and the output current of the solar cell are shown in Fig. 2. In order to obtain as much electric energy as possible from the solar cell, the maximum power tracking problem of the solar cell is proposed. The most common methods for maximum power point tracking control include constant voltage tracking, perturbation observation, conductivity increment, fuzzy logic control, and load current/voltage maximum. . According to the volt-ampere characteristic of LED, in the forward conduction area of ＆#8203;＆#8203;LE D, the slight voltage fluctuation will cause the great change of the electric current, so adopt constant current to drive is the scheme that should choose.

LED lighting artistic performance

The principle of LED lighting. LED is made of III-V compound, such as GaAs (GaAs), GaAsP (AlGaAs), A1GaAs (Aluminum gallium arsenide) and other semiconductors, its core is PN junction, so it has a general PN junction Volt-ampere characteristics, namely forward conduction, reverse cut-off, breakdown characteristics. When the P-type semiconductor and the N-type semiconductor are combined, carrier concentration is poor due to the interface. Therefore, electrons and holes both diffuse from the high-concentration region to the low-concentration region. In this way, one side of the P region loses negative ions that cannot move due to holes, and one side of the N region loses electrons leaving positive ions that cannot move. These non-movable charged particles are space charges. The space charge is concentrated near the interface between the P and N regions, forming a very thin space charge region, which is the P-N junction. When giving P-N junction a forward voltage. It changed the dynamic balance of the P-N junction. When the injected minority carriers (minor sons) and the majority carriers (multiple sons) are combined, excess energy is released in the form of light, thereby converting the electric energy directly into light energy. If a reverse voltage is applied to the PN junction, the minority carriers (the minority sons) are difficult to inject and therefore do not emit light.

White LED main implementation method. At present, GaN-based LED to obtain white light mainly include: blue LED + yellow phosphor, three-color LED synthetic white light, violet LED + three-color phosphor three methods. The most common technique for forming white light is the combination of blue LED chips and phosphors that can be efficiently excited by blue light to form white LEDs. The LED emits blue light with a peak around 470 nm, and some of the blue light-emitting phosphors emit yellow green light with a peak around 570 nm. . The blue light transmitted by the other part is mixed with the yellow-green light generated by the excitation phosphor to generate Y l O :Ce white light. The phosphors currently used are mostly rare earth activated aluminates YlO:Ce (YAG), which emit yellow-green light when blue light excites it, and are therefore called yellow-green phosphors. The method emits light with high luminous efficiency, simple preparation and mature technology. But the color changes with the angle. The optical consistency is poor, and the lifetime of the phosphor and the LED is also inconsistent. As time goes by, the color rendering index and the color temperature will change, affecting the luminous quality of the luminous light source. The use of red, green, and blue primary color LED chips or three primary color LED tubes to achieve white light mixing. The former is a three-chip type, and the latter is a three-tube type. The red, green, and blue LEDs are packaged in a single tube, with a luminous efficacy of up to 20 lm/W, high luminous efficiency, and good color rendering [31. However, the disadvantage of this synthetic white light method is that the LED driver circuit is comparatively complex. The three-chip type three-primary color mixing has a high cost, and since the light decay characteristics of the three kinds of red, green, and blue LEDs are inconsistent, the mixing ratio of the three colors will change as the use time increases. The color rendering index will also change accordingly. The ultraviolet or violet LED will excite the trichromatic phosphor and produce white light. With this method, it is easier to obtain uniform color white light because the color is determined only by the ratio of the phosphors, and in addition, a high color rendering index can be obtained. But its biggest difficulty lies in how to obtain high conversion efficiency of three-color phosphors, especially high-efficiency red phosphors. It is also important to prevent UV leakage.

With the rapid development of China's economy and the rapid expansion of population size, the consumption of energy continues to increase. The development of the city follows the “high energy consumption”. The contradiction between the supply and demand of energy is increasingly prominent, and energy shortage will seriously hinder the future development of the city. . Semiconductor lighting source is an industry with huge market potential. With the advancement of technology. The application of semiconductor light sources will rapidly expand. In the next 5-10 years, it will become the main force of the lighting industry. It will change people's understanding of lighting. The development of a personalized lighting concept is undoubtedly a revolution in lighting. Simultaneously. We must scientifically analyze and calmly face the historical opportunities brought about by semiconductor lighting and formulate scientific development plans to make semiconductor lighting develop healthily.