Solar photovoltaic power generation system has the following characteristics: - no rotating parts, no noise; - no air pollution, no waste water discharge; - no burning process, no fuel; - simple maintenance, low maintenance cost; - operational reliability and stability; - 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;Scaling up as needed is easy. Photovoltaic system is widely used. The basic application forms of photovoltaic system can be divided into independent power generation system and grid-connected power generation system.The main application fields are space shuttle, communication system, microwave relay station, TV differential turntable, photovoltaic pump, no electricity area and home power supply.With the development of technology and the need of sustainable development of the world economy, developed countries have started to systematically promote urban grid-connected photovoltaic power generation, mainly building residential rooftop photovoltaic power generation system and mw centralized large-scale grid-connected power generation system.In terms of transportation and urban lighting, the use of solar photovoltaic system is vigorously promoted. The scale and application forms of photovoltaic systems vary, for example, the scale of the system is large, ranging from 0.3-2w solar courtyard lights, to mw solar photovoltaic power stations, such as 3.75kwp family rooftop power generation equipment, dunhuang 10MW project.Its application form is various, can be widely used in household, transportation, communication, aerospace and other fields.Although the size of photovoltaic system is different, its composition and working principle are basically the same. Photovoltaic module matrix: solar cell modules (also known as photovoltaic cell modules) are formed by means of series and parallel connection according to system requirements, and convert solar energy into electric energy output under sunlight irradiation.It is the core component of solar photovoltaic power generation systemBattery: stores the energy produced by solar cell modules.When light is low 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 load's energy demand.It is a storage solar photovoltaic system.Part ability.At present, solar photovoltaic system is widely used in lead-acid batteries.For demanding systems, a deep discharge valve is usually used to regulate sealed lead-acid batteries and deep discharge aspirated lead-acid batteries. Controller: adjust and control the charging and discharging state of the battery, and control the solar cell module and the power output of 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 solar photovoltaic industry, the function of controller is becoming more and more powerful, and there is a trend to combine the traditional control part, inverter and monitoring system.For example, AES SPP and SMD series controllers integrate the three controllers. Inverter: in a solar photovoltaic power supply system, if an ac load is included, the inverter device converts 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 solar photovoltaic power supply system is that the rechargeable battery can meet the load demand through the sunlight illumination under the control of the controller or under the condition of direct supply load, if the sunlight is insufficient or the battery is controlled by the controller at night.For photovoltaic systems with alternating current load, an inverter is also needed to convert dc to ac.There are many applications of photovoltaic systems, but the basic principles are similar.For other types of photovoltaic systems, only the control mechanisms and system components differ according to actual needs.