What is the meaning of photovoltaic power generation
Photovoltaic power generation is a technology that converts light energy directly into electrical energy by using the photovoltaic effect of semiconductor interface. It is mainly composed of solar panels (components), controllers and inverters, and the main components are composed of electronic components. After the solar cells are packaged and protected in series, a large area of solar cell modules can be formed, and then combined with the power controller and other components to form a photovoltaic power generation device.
Second, the composition and function of photovoltaic power generation
Photovoltaic power generation system is composed of solar cell array, battery, charge and discharge controller, inverter, AC distribution cabinet, solar tracking control system and other equipment. Some of its equipment functions are:
1. Battery array
In the case of light (whether it is sunlight, or the light generated by other luminous bodies), the battery absorbs light energy, and the accumulation of different charges appears at both ends of the battery, that is, the "photo-generated voltage", which is the "photo-generated volt effect". Under the action of the photovoltaic effect, the two ends of the solar cell generate electromotive force, which converts light energy into electrical energy, and is an energy conversion device. Solar cells are generally silicon cells, which are divided into monocrystalline silicon solar cells, polycrystalline silicon solar cells and amorphous silicon solar cells.
2. Battery pack
Its function is to store the electric energy emitted by the solar cell array when it is illuminated and can supply power to the load at any time. The basic requirements for solar cell power generation battery packs are: a. low self-discharge rate; b. Long service life; c. Strong deep discharge ability; d. High charging efficiency; e. Little or no maintenance; f. Wide operating temperature range; g. Low price.
3. Controller
It is a device that can automatically prevent the battery from overcharging and overdischarging. Because the number and depth of charge and discharge of the battery are important factors to determine the service life of the battery, the charge and discharge controller that can control the overcharge or overdischarge of the battery is an essential equipment.
4. Inverter
It is a device that converts direct current into alternating current. Since solar cells and batteries are DC power sources and the load is AC, inverters are essential. Inverter according to the operation mode, can be divided into independent operation inverter and grid-connected inverter.
Independently operated inverters are used in independently operated solar cell power generation systems to power independent loads. Grid-connected inverters are used in grid-connected solar cell power generation systems.
Inverters can be divided into square wave inverters and sine wave inverters according to the output wave type. The circuit of the square wave inverter is simple, the cost is low, but the harmonic component is large, and it is generally used for systems below several hundred watts and the harmonic requirements are not high. Sine wave inverters are costly, but can be adapted to a variety of loads.
5. Tracking system
Because relative to a fixed location of the solar photovoltaic power generation system, a year spring, summer, autumn and winter four seasons, every day sunrise and sunset, the sun's light Angle is always changing, if the solar panel can be at the sun at all times, the power generation efficiency will reach the best state.
The world's general sun tracking control system needs to calculate the Angle of the sun at different times of the year according to the longitude and latitude of the placed point, and store the sun position at each time of the year to the PLC, MCU or computer software, that is, to calculate the sun position to achieve tracking. The use of computer data theory, the need for the earth's latitude and longitude of the data and Settings, once installed, it is inconvenient to move or disassemble, after each move must reset the data and adjust the various parameters; The principle, circuit, technology and equipment are complex, and non-professionals can not operate casually. The solar power generation system equipped with a smart sun tracker is installed in high-speed cars, trains, and communication emergency vehicles, special military vehicles, warships or ships, no matter where the system is going, how to turn, turn, intelligent sun tracker can ensure that the tracking part of the equipment is facing the sun.