As we all know, solar power generation systems have penetrated into every household. I believe everyone has heard of solar power generation systems. Next, let me give you an in-depth introduction.
Solar photovoltaic power generation is a technology that directly converts light energy into electrical energy by using the photovoltaic effect at the semiconductor interface. The key element of this technology is the solar cell. The solar cells are packaged and protected after being connected in series to form a large-area solar cell module, and then cooperate with power controllers and other components to form a photovoltaic power generation device.
The advantage of solar photovoltaic power generation is that it is less restricted by the region, because the sun shines on the earth; the photovoltaic system also has the advantages of safety, reliability, no noise, low pollution, on-site power generation and power supply without consuming fuel and erecting transmission lines, and short construction period.
1. Classification of solar photovoltaic power generation systems
Solar photovoltaic systems are divided into off-grid photovoltaic power generation systems, grid-connected photovoltaic power generation systems and distributed photovoltaic power generation systems:
(1) Off-grid photovoltaic power generation system. It is mainly composed of solar cell components, controllers, and batteries. To supply power to AC loads, an AC inverter is also required.
(2) The grid-connected photovoltaic power generation system is that the direct current generated by solar modules is converted into alternating current that meets the requirements of the mains power grid through a grid-connected inverter, and then directly connected to the public power grid. The grid-connected power generation system has a centralized large-scale grid-connected power station, which is generally a national-level power station. The main feature is that the generated energy is directly transmitted to the grid, and the grid is uniformly deployed to supply power to users. However, this kind of power station has a large investment, a long construction period, and a large area, and has not yet developed much. Distributed small-scale grid-connected power generation systems, especially building-integrated photovoltaic power generation systems, are the mainstream of grid-connected power generation due to their advantages such as small investment, fast construction, small footprint, and strong policy support.
(3) Distributed photovoltaic power generation system, also known as distributed power generation or distributed energy supply, refers to the configuration of smaller photovoltaic power generation and power supply systems at the user site or near the power consumption site to meet the needs of specific users and support the existing distribution network economic operation, or meet the requirements of both aspects at the same time.
2. The composition of solar photovoltaic system
(1). Solar panel: The solar panel is the core part of the solar photovoltaic system. The function of the solar panel is to convert the sun’s light energy into electrical energy, and then output direct current and store it in the battery. The solar panel is one of the most important components in the solar photovoltaic system, and its conversion rate and service life are important factors to determine whether the solar cell has use value.
(2). Controller: The solar controller is composed of a special processor CPU, electronic components, displays, switching power tubes, etc.
(3). Battery: The function of the battery is to store the electric energy generated by the solar panel when there is light, and release it when needed.
(4). Inverter: The direct output of solar energy is generally 12VDC, 24VDC, 48VDC. In order to provide power to 220VAC electrical appliances, it is necessary to convert the DC power generated by the solar photovoltaic system into AC power, so a DC-AC inverter is required.
3. Working principle of solar photovoltaic system
During the day, under light conditions, the solar cell modules generate a certain electromotive force, and form a solar cell square array through the series and parallel connection of the modules, so that the voltage of the square array meets the requirements of the system input voltage. Then the storage battery is charged through the charge and discharge controller, and the electric energy converted from light energy is stored.
At night, the battery pack provides input power for the inverter. Through the function of the inverter, the DC power is converted into AC power, which is sent to the power distribution cabinet, and the power is supplied by the switching function of the power distribution cabinet. The discharge of the battery pack is controlled by the controller to ensure the normal use of the battery. The photovoltaic power station system should also have limited load protection and lightning protection devices to protect the system equipment from overload operation and lightning strikes, and maintain the safe use of system equipment.
(1). Solar energy is inexhaustible, and the solar radiation received by the earth’s surface can meet 10,000 times the global energy demand. As long as solar photovoltaic systems are installed on 4% of the world’s deserts, the electricity generated can meet the needs of the world. Solar power generation is safe and reliable, and will not be affected by energy crises or unstable fuel markets;
(2). Solar energy can be used anywhere, and can supply power nearby without long-distance transmission, avoiding the loss of long-distance transmission lines;
(3). Solar energy does not require fuel, and the operating cost is very low;
(4). Solar power generation has no moving parts, is not easy to use and damage, and is easy to maintain, especially suitable for unattended use;
(5). Solar power generation will not produce any waste, has no pollution, noise and other public hazards, and has no adverse effects on the environment. It is an ideal clean energy source;
(6). The solar power generation system has a short construction period, is convenient and flexible, and can arbitrarily add or reduce the amount of solar phalanx according to the increase or decrease of load to avoid waste.
5. Application field of solar photovoltaic power generation system.
(1). User solar power supply:
1) small power supply ranging from 10-100W, used for military and civilian life in remote areas without electricity, such as plateaus, islands, pastoral areas, frontier posts, etc., such as lighting, TV, tape recorders, etc.;
2) 3 – 5KW home roof grid-connected power generation system;
3) Photovoltaic water pump: solve the drinking and irrigation of deep water wells in areas without electricity.
(2). Traffic field: such as beacon lights, traffic/railway signal lights, traffic warning/sign lights, high-altitude obstruction lights, highway/railway wireless telephone booths, unattended road shift power supply, etc.
(3). Communication/communication field: solar unattended microwave relay station, optical cable maintenance station, broadcast/communication/paging power system; rural carrier telephone photovoltaic system, small communication machine, GPS power supply for soldiers, etc.
(4). Petroleum, ocean, and meteorological fields: solar power systems for cathodic protection of oil pipelines and reservoir gates, domestic and emergency power supplies for oil drilling platforms, marine testing equipment, meteorological/hydrological observation equipment, etc.
(5). Power supply for household lamps: such as garden lamps, street lamps, portable lamps, camping lamps, mountaineering lamps, fishing lamps, black light lamps, rubber tapping lamps, energy-saving lamps, etc.