Photovoltaic power generation is based on the principle of photovoltaic effect, using solar cells to directly convert light energy into electrical energy. Whether it is off-grid power generation or grid-connected power generation, the photovoltaic power generation system is mainly composed of solar modules, solar controllers and inverters.
Off-grid power generation also requires batteries to store excess power for insufficient light or night use. They are mainly composed of electronic components and do not involve mechanical parts. Therefore, photovoltaic power generation equipment is extremely refined, reliable and stable, long life, and easy to install and maintain.
1. Photovoltaic modules
It is composed of photovoltaic cell components in series and parallel according to the system requirements, and converts solar energy into electrical energy output under the irradiation of sunlight. It is the core component of the solar PV system.
The electrical energy generated by the solar cell module is stored, and when the light is insufficient, at night, or when the load demand is greater than the power generated by the solar cell module, the stored electrical energy is released to meet the energy demand of the load.
It is the energy storage component of solar PV system. At present, lead-acid batteries are commonly used in solar PV systems. For systems with higher requirements, deep-discharge valve-regulated sealed lead-acid batteries, deep-discharge liquid-absorbing lead-acid batteries, etc. are usually used.
It regulates and controls the charging and discharging conditions of the battery, and controls the power output of the solar cell components and the battery to the load according to the power demand of the load. It is the core control part of the entire system.
With the development of the solar photovoltaic industry, the functions of the controller are becoming more and more powerful, and there is a trend to integrate the traditional control part, inverter and monitoring system.
If there is an AC load in a solar PV system, an inverter device is used to convert the DC power generated by the solar cell module or the DC power released by the battery into the AC power required by the load.
The basic working principle of the solar photovoltaic power supply system is to charge the battery with the electric energy generated by the solar cell module under the irradiation of sunlight through the control of the controller, or directly supply power to the load when the load demand is met.
If the sunlight is insufficient or at night, the battery will supply power to the DC load under the control of the controller. For the photovoltaic system with AC load, it is necessary to add an inverter to convert the DC power into AC power.
The advantage of photovoltaic power generation is that it is less restricted by geographical areas, because the sun shines on the earth, and the photovoltaic system also has the advantages of safety and reliability, no noise, low pollution, no need to consume fuel and erect transmission lines, and can generate electricity and power locally, and the construction period is short.