Views:3 Author:Site Editor Publish Time: 2021-06-11 Origin:Site
The photovoltaic power generation system is usually divided into grid-connected power generation and off-grid power generation. Grid-connected power generation is to convert the received solar radiation energy through high-frequency DC into high-voltage DC through photovoltaic modules, and then output alternating current after inverter, which is incorporated into the national grid. Off-grid power generation is self-use, local consumption, more flexible application.
Conventional photovoltaic power generation system is mainly composed of photovoltaic array, charge and discharge controller, energy storage equipment or inverter (reverse control integrated machine can be used in this link, which is convenient and more efficient), load, etc. The output current of the photovoltaic array is unstable due to the influence of the environment. The output current of the photovoltaic array needs to be converted into a stable current through a converter before it can be loaded onto the battery to charge the battery, which then supplies power to the load. If it is connected to the grid to sell electricity, it does not need a battery, but through the grid-connected inverter, the DC current flow into AC current, and to the grid for sale. In other words, off-grid photovoltaic power generation systems must use battery energy storage, while grid-connected systems do not necessarily need it.
In fact, in real life, because the off-grid photovoltaic power generation system is not subject to regional restriction, using a wide range, as long as there is sunlight can install and use, so is very common, such as solar street lamps, traffic lights, agricultural pesticides lamp, etc., especially suitable for some of the power grid can't cover remote grid area, island, fishing boats, outdoor breeding base, etc., It can also be used as emergency power generation equipment in areas with frequent power failure.
Solar power generation refers to the process of converting solar energy into electricity that can be used by humans. It mainly includes two forms of photothermal power generation and photovoltaic power generation. For solar thermal power generation, we may be more familiar with, for example, the solar water heater has been popularized, its power generation process requires sufficient direct light and sufficient water, so the construction of solar thermal system on the terrain and construction area lighting resources requirements are relatively harsh.
Compared with photothermal power generation, photovoltaic power generation has lower requirements on natural resources. In addition, it can make more full use of the total solar radiation and has good terrain compatibility. Therefore, photovoltaic power generation has considerable advantages and is the main way to utilize sunlight. In the last stage of science we learned that the photovoltaic power generation system is mainly composed of inverter (to convert direct current to alternating current), solar cell (to convert light energy to electricity), controller (control charge and discharge), battery (storage or supply of electricity) four parts.
Photovoltaic power generation is based on light born v effect, the solar cell is the foundation of the solar photovoltaic power generation systems and core components, the sun light energy can be converted into electrical energy directly, when light solar cell surface, part of a photon is absorbed by silicone material, photonic energy transmitted to the silicon atoms, the electron transition occurs, become free electrons, agglomeration formation potential difference on both sides of the PN junction. When the external circuit is connected, under the action of this voltage, there will be a current flowing through the external circuit to produce a certain output power. The essence of this process is the conversion of photon energy into electrical energy.