Photovoltaic power generation is based on the principle of photovoltaic effect, using solar cells to directly convert sunlight energy into electrical energy. Whether it is used independently or connected to the grid, the photovoltaic power generation system mainly consists of three parts: solar panels (modules), controllers and inverters. They are mainly composed of electronic components, but do not involve mechanical parts.
1. Solar cell module
A solar cell can only generate a voltage of about 0.5V, which is much lower than the voltage required for actual use. In order to meet the needs of practical applications, solar cells need to be connected into modules. Solar cell modules contain a certain number of solar cells, which are connected by wires. For example, the number of solar cells on a module is 36, which means that a solar module can generate a voltage of about 17V.
The physical unit sealed by solar cells connected by wires is called a solar cell module, which has certain anti-corrosion, windproof, hailproof and rainproof capabilities and is widely used in various fields and systems. When the application field requires higher voltage and current and a single module cannot meet the requirements, multiple modules can be combined into a solar cell array to obtain the required voltage and current.
2. DC/AC inverter
Equipment that converts direct current into alternating current. Since solar cells generate direct current, and the general load is an AC load, an inverter is indispensable. Inverters can be divided into independent inverters and grid-connected inverters according to the operating mode. Independent inverters are used for independent solar cell power generation systems to supply power to independent loads. Grid-connected inverters are used for grid-connected solar cell power generation systems to feed the generated power into the grid. Inverters can be divided into square wave inverters and sine wave inverters according to the output waveform.
3. Distribution room design
Since the grid-connected power generation system does not have batteries, solar charge and discharge controllers, and AC and DC distribution systems, if conditions permit, the grid-connected power generation system inverter can be placed in the low-voltage distribution room of the grid connection point, otherwise, just build a separate low-voltage distribution room of 4 to 6m2.