(1) solar cell array. The solar cell phalanx consists of a solar cell combination board and a phalanx bracket. Because the voltage of a single solar cell is generally low, it is usually necessary to connect them in series and parallel to form a practical solar panel as an application unit, and then connect multiple application units in series and parallel to form a solar cell square according to the power supply requirements. Solar panels (some semiconductor materials, mainly polysilicon, monocrystalline silicon and amorphous silicon, are assembled by a certain process) are the most important part of solar photovoltaic system and the most valuable part of solar photovoltaic power generation system. When the solar panel emits light, the battery absorbs light energy, and charges with different signs are accumulated at both ends of the battery, which produces "photovoltaic voltage", which is the "photoelectric effect". Under the photoelectric effect, electromotive force is generated at both ends of the solar cell, which converts light energy into electric energy. This is an energy conversion device.
(2) battery pack. Its function is to store the electric energy generated when the solar cell array emits light, and supply power to the load at any time. In the solar grid-connected power generation system, there is no need to add storage batteries.
(3) the controller. A device for regulating and controlling electric energy.
(4) inverter. It is a device that converts direct current provided by solar cell array and storage battery into alternating current, and it is a key component of photovoltaic grid-connected power generation system. Because solar cells and storage batteries are DC power supplies, when the load is AC load, the inverter is essential. Inverter can be divided into independent operation inverter and grid-connected inverter according to operation mode. Independently operated inverters are used in independently operated solar cell power generation systems to supply power to independent loads. Grid-connected inverter is used in grid-connected solar cell power generation system. This paper mainly introduces the solar photovoltaic grid-connected power generation system [1]. As shown in figure 1, the grid-connected inverter consists of igbt and other power switching devices. The control circuit makes the switching device turn on or off continuously according to a certain rule, so that the polarity of the output voltage is alternately positive and negative, and the DC input is converted into AC output. Inverter can be divided into square wave inverter and sine wave inverter according to output waveform. Square-wave inverter has simple circuit and low cost, but it has large harmonic components, and is generally used in systems with low harmonic requirements below several hundred watts. Sine wave inverter is expensive, but it can be applied to various loads.