The solar cell power generation system is made by using the principle of photovoltaic effect. It is a power generation system that directly converts solar radiation energy into electrical energy. It mainly consists of two parts: solar cell array and inverter. As shown in the figure below: When there is sunshine during the day, the electricity generated by the solar cell array is directly transmitted to the AC power grid through the grid-connected inverter, or the electricity generated by solar energy is directly supplied to the AC load through the grid-connected inverter.
Solar photovoltaic power generation relies on solar cell modules and the electronic properties of semiconductor materials. When sunlight shines on the semiconductor PN junction, the P-N junction barrier region generates a strong built-in electrostatic field, so the unbalanced electrons and holes generated in the barrier region or the unbalanced electrons and holes generated outside the barrier region but diffused into the barrier region, under the action of the built-in electrostatic field, move in opposite directions and leave the barrier region, resulting in an increase in the potential of the P region and a decrease in the potential of the N region, thereby generating voltage and current in the external circuit, converting light energy into electrical energy.
Solar photovoltaic power generation systems can be roughly divided into two categories. One is the grid-connected power generation system, which is connected to the public power grid through a standard interface, like a small power plant; the other is the independent power generation system, which forms a circuit inside its own closed-circuit system. The grid-connected power generation system converts the received solar radiation energy into high-voltage direct current through the photovoltaic array through high-frequency direct current conversion, and then outputs a sinusoidal alternating current with the same frequency and phase as the grid voltage to the grid after being inverted by the inverter. The photovoltaic array of the independent power generation system will first convert the received solar radiation energy directly into electrical energy to supply the load, and store the excess energy in the battery in the form of chemical energy after passing through the charging controller.