Design process of distributed photovoltaic power station

From the perspective of development in recent years, with the country`s increasing environmental protection requirements, new energy has also been widely used, especially the installed capacity of photovoltaic and distributed energy power generation has begun to replace part of the proportion of old energy in my country`s energy structure.
In accordance with China's relevant industrial policies, the national government takes an active and encouraging attitude towards the development of the photovoltaic industry, supports grid-connected photovoltaic power generation, and has issued relevant preferential policies, and the establishment of a distributed grid-connected photovoltaic power plant system can have a protective effect on the environment , Save energy, reduce emissions and other good effects. The design scheme of distributed grid-connected photovoltaic power station system needs to be standardized and standard. It is not only necessary to ensure that the distributed grid-connected photovoltaic power station system can be used effectively, but also the efficiency of distributed photovoltaic system and the efficiency of distributed grid-connected photovoltaic power station system. Design schemes, protection and prevention, etc. are improved, so based on the above reasons, it is very necessary to analyze the design scheme of distributed grid-connected photovoltaic power station system.
Tools/Materials:
1. Calculator
2. Parameter report
3. Tape Measure
4. Measuring tape
5. Multimeter
Method/Step:
1. Calculate the capacity of the system;
2. Determine the battery board (category, parameter, quantity, etc.);
3. Estimate the string design (preliminarily estimate the size of the box);
4. Determine the number and size of the combiner box;
5. Select the cable type, quantity and size;
6. Choose the inverter model, quantity and size;
7. Determine the number and size of grid-connected cabinets;
8. Design a monitoring system (with or without a large LCD screen, consider the power supply);
9. Determine the fixed installation form of the components;
10. Preliminarily planned equipment installation location and equipment installation quantity
System Components:
Rooftop solar photovoltaic power station systems generally form multi-level confluence, inverter, pressurization, etc. through rooftop photovoltaic module arrays, combiner boxes, DC distribution cabinets, low-voltage AC cabinets, inverters, step-up transformers, high-voltage AC cabinets, and cables. Grid-connected system composition. The photovoltaic array combiner box can carry out an orderly maintenance, convergence and lightning protection function maintenance device for the solar cell components. This device can ensure that the photovoltaic system is easier to separate the circuit during maintenance and inspection. When the photovoltaic module has a problem, try to avoid the number of components that are removed from the system. It can be regarded as the confluence facility of the photovoltaic power generation system on the DC side. The photovoltaic array combiner box is installed outdoors on the roof photovoltaic module square array field. After the photovoltaic module array uses the combiner box to carry out the confluence outdoors, it is connected to the DC power distribution cabinet in the machine room through the cable to implement the second confluence. The DC power distribution cabinet sends the DC power after the second confluence to the grid-connected inverter through the cable, and the grid-connected inverter converts it into a sine wave current with the same phase and frequency as the AC grid, and then feedback after boosting Back to the grid to complete the grid-connected power generation effect.
Installation of photovoltaic modules:
Photovoltaic modules are combined by a large number of bulk crystalline silicon cells or thin-film cells. Installed on the roof, they can convert the received solar radiation into electrical energy. Due to the obstacles of material research and technology, it is very difficult to improve the conversion efficiency of solar cells. Therefore, the installation of photovoltaic modules is an effective measure to improve the efficiency of distributed grid-connected photovoltaic power plants. The installation of photovoltaic modules should be based on factors such as the latitude and longitude of the urban area where the project is located, geography, geology, and architectural direction, combined with on-site development, so that the modules are exposed to sunlight as much as possible. In addition, for its installation, it is mainly determined from the inclination and spacing.
Installation inclination angle of photovoltaic modules:
Because there is an angle between the equatorial plane of the earth and the ecliptic plane, the sun`s direct point of radiation changes between the Tropic of Cancer and the Tropic of Cancer within a year, and the maximum angle of solar radiation received by a site in each season will also change. Therefore, in order to make the plane of photovoltaic modules receive the maximum amount of solar radiation for a long time, the inclination angle of the photovoltaic module installation can not only be based on the latitude value, nor can it be compared with the angle of the maximum amount of solar radiation when the solar radiation is lowest on the horizontal plane. Set as the inclination angle of the module. If this is done, the solar radiation from the module plane will be reduced in summer. The installation inclination angle of photovoltaic modules should be specified according to the average annual solar radiation on the different inclination planes in various regions.
Precautions:
· Calculation data adopt conservative data
· The calculation requirements are more accurate