The correct method should be followed when selecting solar photovoltaic inverters

Photovoltaic inverter is the main component and important part of solar photovoltaic power generation system. In order to ensure the normal operation of solar photovoltaic power generation system, it is important to correctly configure and select photovoltaic inverter. In addition to the configuration of the inverter, it should be determined according to the technical indicators of the entire photovoltaic power generation system and refer to the product sample manual provided by the manufacturer. Generally, the following technical indicators should also be considered.

1. Rated output power

The rated output power indicates the ability of the photovoltaic inverter to supply power to the load. A photovoltaic inverter with a high rated output power can carry more electrical loads. When selecting a photovoltaic inverter, the first consideration should be whether it has sufficient rated power to meet the power requirements of the equipment under maximum load, as well as the expansion of the system and the access of some temporary loads. When the electrical equipment is powered by a purely resistive load or the power factor is greater than 0.9, the rated output power of the photovoltaic inverter is generally selected to be 10%-15% greater than the total power of the electrical equipment.

2. Output voltage adjustment performance

The output voltage adjustment performance indicates the voltage regulation capability of the photovoltaic inverter output voltage. Generally, photovoltaic inverter products provide the percentage of fluctuation deviation of the photovoltaic inverter output voltage when the DC input voltage fluctuates within the allowable fluctuation range, which is usually called voltage adjustment. High-performance photovoltaic inverters should also provide the percentage of deviation of the photovoltaic inverter output voltage when the load changes from zero to 100%, which is usually called load adjustment. The voltage adjustment rate of a photovoltaic inverter with excellent performance should be less than or equal to ±3%, and the load adjustment rate should be less than or equal to ±6%.

3. Overall efficiency

The overall efficiency indicates the power loss of the photovoltaic inverter itself. A photovoltaic inverter with a larger capacity should also provide efficiency values ​​under full load and low load. Generally, the efficiency of inverters below the KW level should be above 85%; the efficiency of the 10KW level should be above 90%; the efficiency of higher power must be above 95%. The efficiency of the inverter has an important impact on the increase of effective power generation and the reduction of power generation costs of the photovoltaic power generation system. Therefore, when selecting photovoltaic inverters, try to compare and choose products with higher overall efficiency.

4. Startup performance

Photovoltaic inverters should ensure reliable startup under rated load. High-performance photovoltaic inverters can achieve multiple consecutive full-load startups without damaging power switch devices and other circuits. For their own safety, small inverters sometimes use soft start or current limiting start measures or circuits.

The above items are the main basis for the design and selection of photovoltaic inverters, and are also important indicators for evaluating the technical performance of photovoltaic inverters.