Selection Principles of Inverters in Industrial and Commercial Power Plants

The application purpose of industrial and commercial power stations is mainly to reduce electricity expenses and maximize self-generation and self-use.
 
In the process of building an industrial and commercial power station, there are many issues that need to be considered, such as power consumption level, construction site, grid connection, process approval, etc. All owners are more concerned about the initial investment costs because they are related to the costs of electricity. As an important control device in a photovoltaic power station, the selection and configuration of the inverter is not only related to the stability and output capacity of the system, but also has an important impact on the costs of electricity. Therefore, the selection of the inverter is crucial.
 
1. Industrial and commercial power station inverters should be large and not small
 
The large here refers to the output power of the inverter. Industrial and commercial power stations generally have a total capacity of several hundred kilowatts to 10MW+. If an inverter with a smaller rated output is selected, the number will be greatly increased. Correspondingly, it is necessary to increase cables, power distribution facilities, grid-connected devices (grid-connected points), and more construction costs also increase potential points of failure.  
Therefore, when the number of strings is determined, the model with higher power is given priority. In addition, the selection should also pay attention to the uniformity of the equipment, and the model should not be too complicated, so as to minimize the trouble to the later measurement, operation and maintenance.
 
2. Choose a model that supports high-current components
 
At present, the mainstream components on the market are mainly 182 type and 210 type. The open circuit voltage of 182 type components is high, generally at 49.XX V, and the current is small, generally at 13.XX A; while the open circuit voltage of 210 components is low, generally around 40V , but the current is very large, ranging from 17A to 20A+. The corresponding inverters of various manufacturers allow the input current to be around 16A. Matching 182-type components is very flexible, it can be connected in series and can achieve the required capacity ratio, but matching 210-type components will be limited by capacity.
 
3. Component decentralized inverters need to be centralized
 
Industrial and commercial power stations are mostly built on the roofs of factories or buildings, and often a power station covers multiple roofs. The roofs or sites are of different sizes, and the number of components installed is different, so the power they carry is also different. If the inverter is simply selected according to the power of each area, it is likely that there will be multiple models, which will be troublesome when selecting cables and power distribution devices, and increase the probability of errors during installation.
 
Therefore, this kind of project should generally be considered as a whole first, and the appropriate inverter should be selected according to the total component power, and the model should be as uniform as possible.
 
Cases that cannot be incorporated into the whole include: component arrays that are installed too far away, component arrays with completely different orientations, component arrays with hard occlusion, components with inconsistent specifications or models, and so on.
 
4. Always pay attention to improve the capacity ratio
 
The capacity ratio is also very important in industrial and commercial power plants, which is related to the initial investment cost and the power generation efficiency of the system.
 
The principle of inverter selection is to reduce the system cost of equipment, increase the power generation of the system, reduce the construction cost of the system, the cost of auxiliary materials, and the difficulty of construction and operation and maintenance. In the implementation of specific projects, it is recommended to refer to and apply flexibly.