Design selection category

The installation angle of photovoltaic arrays is mainly determined by the longitude, latitude, and optimal radiation dose of the installation area. Due to installation conditions, if the installation angle of the components cannot reach the optimal level, the angle can be adjusted appropriately. The power generation of non south facing roofs will be greatly affected.

Due to the main factor affecting photovoltaic power generation being the amount of sunlight, components should be installed in the direction with the most abundant sunlight. Different installation angles also have an impact on the power generation efficiency of photovoltaic modules. The following figure shows the different efficiencies of photovoltaic modules in different orientations in a city in southern China. (Note: The power generation efficiency of photovoltaic cells in different orientations varies depending on the location and climate conditions.)

Photovoltaic inverters are generally selected as outdoor type, using natural cooling method, with high shell protection level (usually up to IP65), requiring minimal environmental modification for installation, and low cost; Meanwhile, as the inverter is installed outdoors, the noise generated by its operation will greatly reduce its impact on users, but good equipment protection is required.

Generally, inverters for the corresponding power range are configured according to the system requirements, and the selected inverter power should match the maximum power of the photovoltaic cell array. The rated output power of the photovoltaic inverter is generally selected to be close to the total input power (usually controlled within 1.3 for overloading), which can save costs.

On the other hand, inversionThe selection of device capacity size can be optimized according to installation conditions. If the installation site is not clear in the early stage of design, and the installation site is not fully considered, low-power photovoltaic inverters should be selected as much as possible to achieve multi-channel independent power tracking. If necessary, micro inverters should be selected to achieve maximum power tracking of smaller units, so as to ensure the problem of series parallel mismatch caused by insufficient or irregular site in the later stage.

According to the specific situation of the installation site, different types and specifications of photovoltaic modules can be selected. The effective utilization area of the installation site determines the size of the modules. If you want to install a larger capacity per unit area, high-efficiency modules can be selected. Components with different border colors can also be selected based on the appearance of the existing building, and the length of the component connectors can be determined according to the on-site series parallel connection method.

The selection of components requires comprehensive consideration of factors such as installation area, installed capacity, and cost. Generally speaking, component products with good reputation, good quality, certification (including fire rating), and good quality assurance and after-sales service should be selected.

As the core component of photovoltaic systems, inverters directly affect the system's power generation. The following points should be noted:

(1) Due to the connection between the inverter and the power grid changing the impedance characteristics of the inverter, it is easy to cause resonance of the inverter itself, which often occurs when multiple inverters are connected in parallel;

(2) After the installation of the inverter, a dedicated person must conduct a re inspection, mark and record it;

(3) The connection between the inverter ventilation duct and the external duct should be made with a soft connection to prevent mechanical noise caused by mechanical vibration;

(4) When the noise and odor of the inverter increase, attention should be paid, and internal faults of the inverter should be checked to identify the cause and handle it accordingly;

(5) Pay attention to the detection of inverter leakage, grounding, phase sequence, etc. during installation and debugging;

(6) At least 2 people must be present at the same time during inverter debugging, and attention should be paid to the safety protection of operators.