The solar photovoltaic system consists of three parts: solar modules; power and discharge devices such as charge and discharge controllers, frequency converters, test instruments and computer monitors, and batteries or other energy storage and auxiliary power generation equipment.
The solar photovoltaic system has the following characteristics:
- no rotating parts, no noise;
- does not pollute the air and does not discharge waste water;
- no combustion process required, no fuel required;
- Simple maintenance and low maintenance costs;
- operational reliability and stability;
- The long life of solar cells is a key component of solar cells, and the life of crystalline silicon solar cells can reach more than 25 years;
It is easy to expand the scale of power generation as needed.
Photovoltaic systems are widely used, and the basic forms of photovoltaic system applications can be divided into two categories: independent power generation systems and grid-connected power generation systems. The main application areas are space shuttles, communication systems, microwave relay stations, TV differential turntables, photovoltaic pumps, power-free areas and home power supply. With the development of technology and the need for sustainable development of the world economy, developed countries have begun to systematically promote urban photovoltaic grid-connected power generation, mainly building residential rooftop photovoltaic power generation systems and mw-class centralized large-scale grid-connected power generation systems. In the area of transportation and urban lighting, the use of solar photovoltaic systems is vigorously promoted.
The scale and application form of photovoltaic systems vary, such as the scale of the system, from 0.3 – 2W solar garden lights, to mw-class solar photovoltaic power plants, such as 3.75kWp home rooftop power generation equipment, Dunhuang 10MW project. Its application forms are diverse and can be widely used in home, transportation, communication, aerospace and other fields. Although the size of the photovoltaic system is different, its composition and working principle are basically the same.
Photovoltaic module matrix: Solar cell module (also known as photovoltaic cell module) is formed by series-parallel method according to system requirements, and converts solar energy into electric energy output under sunlight. It is a core component of solar photovoltaic systems.
Battery: Stores the energy produced by the solar module. When the light is insufficient or at night, or when the load demand is greater than the power generated by the solar module, the stored energy is released to meet the energy requirements of the load. It is a storage solar photovoltaic system. Part of the ability. At present, solar photovoltaic systems are widely used in lead-acid batteries. For demanding systems, deep discharge valves are often used to regulate sealed lead-acid batteries and deep discharge aspirating lead-acid batteries.
Controller: adjusts and controls the charge and discharge state of the battery, and controls the power output of the solar cell module and the battery to the load according to the power demand of the load, which is the core control part of the whole system. With the development of the solar photovoltaic industry, the functions of the controller are becoming more and more powerful, and there is a tendency to combine the traditional control part, the inverter and the monitoring system. For example, the AES SPP and SMD series controllers integrate the three controllers described above.
Inverter: In a solar photovoltaic power system, if an AC load is included, the inverter device converts the DC power generated by the solar battery module or the DC power discharged from the battery into the AC power required by the load.
The basic working principle of the solar photovoltaic power supply system is that the rechargeable battery meets the load demand under the control of the solar light under the control of the controller or directly under the load, if the sunlight is insufficient or the battery is controlled by the controller at night. For photovoltaic systems with AC loads, an inverter is also required to convert DC power to AC power. Photovoltaic systems are used in many forms, but the basic principles are similar. For other types of photovoltaic systems, only the control mechanisms and system components vary according to actual needs.
