With the continuous development of photovoltaic technology, solar street lights are becoming more and more common in our lives. We all know that after solar light passes through the light during the day, the light energy is converted into electrical energy and then stored by the battery. At night, the battery Even the light source provides power to achieve lighting effects.
So how exactly does it make the light source be converted into electrical energy through solar panels and stored? In this process, what kind of configuration will be involved? Let's take a closer look at it.
First, the principle of solar street light photovoltaic module power generation
Solar street lights can generate electricity mainly by using the photovoltaic effect of semiconductor materials, which can convert solar light radiation into electricity.
A solar cell is composed of two different types of semiconductors, N-type and P-type. The junction between them is called a PN junction. When the solar panel receives light, it will be released in this PN junction because it has obtained light energy. Electrons, generating corresponding electron-hole pairs.
The holes of the N-type semiconductor will move to the P-type, and the electrons in the P-type region will forget the N-type region to move, forming a current from the N-type region to the P-type region. Power is output.
Second, the power generation system configuration
Solar street light power generation systems are mainly composed of solar panels, control and storage batteries. If the output power is AC 220V or 110V, inverters will also be involved, so what role will they play in this process?
As the core part of the power generation system, as mentioned above, it mainly plays the role of converting light energy into electrical energy, and then sends it to the battery for storage, which is convenient for night lighting or to promote load work.
The full name is the solar charge-discharge controller. From this name, you can understand its role. It is used to control the working state of the entire system, and it also plays a protective role for the battery.
The street light control and time control functions are also implemented on the above, which can be selected according to specific needs. If the temperature difference between the places where the solar street lights are installed is large, the controller often has a function of temperature compensation to better adapt to the environment.
In the past, lead-acid batteries were commonly used, but now they are gradually being replaced by lithium iron phosphate batteries. The main purpose is to store the electrical energy converted by solar panels and release them when needed at night.
The direct output of solar energy is generally the current voltage of 12V, 24V, 48V. If it is necessary to provide AC power of 220V, 110V, then a DC-AC inverter is needed, which can convert the DC power generated by the solar power generation system into AC power.
And when some loads need to use multiple voltages, such as the need to convert 24V DC power to 5V DC power, then a DC-DC inverter will be needed.