The design principle of solar street lights
I. Introduction
With the increasing scarcity of the earth's resources, the investment cost of basic energy is rising, and various safety and pollution risks are everywhere. Solar energy is becoming an inexhaustible and safe new energy source. The more attention is paid. At the same time, with the development and progress of solar photovoltaic technology, solar lighting products have double advantages in environmental protection and energy conservation, and the application of solar street lamps, garden lamps and lawn lamps has gradually formed scale. The development of solar power in the field of street lighting has been gradually improved. . The author's experience on the design of solar street lights is for peer reference.
Second, the composition of solar street lights
The solar street light consists of the following components: solar panels, solar controllers, battery packs, light sources, poles and fixture housings. If the output power is AC 220V or 110V, configure the inverter.
1. Solar panels:
Solar panels are the core of solar streetlights and the most valuable part of solar streetlights. Its role is to convert the solar radiation capacity into electrical energy, or send it to the battery for storage. Among the many solar cells, there are three types of monocrystalline silicon solar cells, polycrystalline silicon solar cells and amorphous silicon solar cells. In the eastern and western regions where sunlight is abundant, it is better to use polycrystalline silicon solar cells because the production process of polycrystalline silicon solar cells is relatively simple and the price is lower than that of single crystal. In the southern regions where there are more rainy days and less sunshine, it is better to use monocrystalline silicon solar cells because the performance parameters of monocrystalline silicon solar cells are relatively stable. Amorphous silicon solar cells are better in the case of insufficient outdoor sunlight, because amorphous silicon solar cells have lower requirements for solar lighting conditions.
2, solar controller
Regardless of the size of the solar luminaire, a good performance charge and discharge controller is essential. In order to extend the life of the battery, its charging and discharging conditions must be limited to prevent overcharging and deep charging of the battery. In places with large temperature differences, qualified controllers should also have temperature compensation. At the same time, the solar controller should have the function of street light control, with light control and time control functions, and should have the function of automatic cutting and controlling load at night, which is convenient for extending the working time of street lamps in rainy days.
3, battery
Since the input energy of the solar photovoltaic system is extremely unstable, it is generally necessary to configure the battery system to work. Generally, there are lead-acid batteries, Ni-Cd batteries, and Ni-H batteries. The choice of battery capacity generally follows the following principles: First, the energy of the daytime solar cell module is stored as much as possible while meeting the nighttime illumination, and at the same time, it is also necessary to store the electric energy required for the nighttime illumination of the continuous rainy day. If the battery capacity is too small, it can not meet the needs of night lighting. The battery is too large. On the one hand, the battery is always in a deficient state, which affects the battery life and causes waste. The battery should match the solar battery and the electrical load (street light). A simple way to determine the relationship between them. The solar cell power must be more than 4 times higher than the load power for the system to work properly. The voltage of the solar cell should exceed 20~30% of the working voltage of the battery to ensure normal negative charge to the battery. The battery capacity must be more than 6 times higher than the daily load of the load.