3、政府部門、企事業(yè)單位辦公大樓供電：集中安裝在辦公大樓的頂層，作為公用電接入大樓低壓配電柜中。

（Off grid solar photovoltaic power generation system



1、 System composition



The off grid solar photovoltaic power generation system is mainly composed of five parts: solar panel, battery pack, solar controller, converter and monitoring system. Figure 1 is the schematic diagram of photovoltaic power generation system, and Figure 2 is the schematic block diagram of system composition. The functions and functions of each part are:



1. Photovoltaic panel: it is the core of photovoltaic power generation. Its function is to directly convert solar radiation energy into DC energy to supply load or store it in battery.



2. Photovoltaic controller: because the output of general monocrystalline silicon or polycrystalline silicon photovoltaic panels is current source type, they cannot be directly output to loads and batteries. They need to be transformed into stable voltage or current acceptable to the battery through the photovoltaic controller to realize the effective charging of the battery or supply external loads. The photovoltaic controller can also realize the overshoot and over discharge protection function of the battery pack.



3. Inverter; If the output is required to be DC, the voltage of the battery can be converted into different DC voltage through this part to adapt to different load equipment. If the output is AC, it can be changed into AC 220V (single-phase) and 380V (three-phase) through DC. For household use, this part generally purchases AC inverter.



4. Monitoring system: the main function of this part is to monitor the working parameters and working status of each part, and provide man-machine operation interface at the same time.

2、 System functions and features



1. It can realize the constant voltage and constant current charging of the battery and the automatic management of the charging process;



2. It has the solar maximum power point tracking control function (MPPT), giving full play to the maximum efficiency of photovoltaic cells; 3. The inverter has good sinusoidal output waveform, stable output voltage and strong anti-interference ability;



4. The protection function is perfect, with battery overcharge, over discharge, output overvoltage, overcurrent, short circuit and other protection;



5. It has the backup function of AC power supply. When there is no sunlight for many days, and the stored electric energy of the battery cannot meet the output power supply, the system can automatically switch to AC mains power supply. Since the DC side is adopted, there is no interruption in AC output; 6. Friendly man-machine operation interface and perfect monitoring function. The system adopts large-size touch LCD screen, which is convenient to operate and intuitive to display;



3、 System adaptation field



1. Household power supply: it is especially suitable for families living independently, such as urban villas and rural families. For urban residential areas, households living on the top floor or families with large private balconies are also more suitable;



2. School power supply: it is especially suitable for primary and secondary schools and kindergartens. In these places, there is usually more electricity during the day, and the electricity consumption is small;



3. Hospital power supply: it can be integrated with the emergency power supply system of the hospital, which can effectively improve the reliability and economy of the emergency power supply of the hospital;



4. Public power supply of urban community: it can be installed in the public part of urban community, connected to the public electricity room of the community, and used as the public electricity of the community;

3. Power supply for office buildings of government departments, enterprises and institutions: it is centrally installed on the top floor of the office building and connected to the low-voltage distribution cabinet of the building as public power.
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