What are the parameters to be considered for solar pv inverters？

The configuration of the solar inverter should be determined according to the technical specifications of the entire pv power generation system and referring to the product sample manual provided by the inverter manufacturer. Generally, the following technical indicators should be considered.

1. Rated output power

The rated output power indicates the ability of the pv inverter to supply power to the load. pv inverters with high rated output power can carry more electrical loads. When choosing a pv inverter, you should first consider having sufficient rated power to meet the electrical power requirements of the device under maximum load, as well as system expansion and access to some temporary loads. When the electrical equipment is based on a purely resistive load or the power factor is greater than 0.9, the rated output power of the pv inverter is generally selected to be 10% to 15% greater than the total power of the electrical equipment.

2. Adjustment performance of output voltage

The adjustment performance of the output voltage indicates the ability of the pv inverter to stabilize the output voltage. General pv inverter products give the percentage of the fluctuation deviation of the output voltage of the pv inverter when the DC input voltage fluctuates within the allowable fluctuation range, which is usually called the voltage regulation rate. The high-performance pv inverter should also give the percentage of deviation of the output voltage of the pv inverter when the load changes from zero to 100%, usually called the load regulation rate. The voltage adjustment rate of a pv 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 represents the size of the PV inverter’s own power loss. Large-capacity pv inverters must also give efficiency values ​​under full-load operation and low-load operation. In general, the efficiency of inverters below KW level should be above 85%; the efficiency of 10KW level should be above 90%; the efficiency of larger power must be above 95%. The efficiency of the inverter has an important impact on the pv power generation system to increase the effective power generation and reduce the cost of power generation. Therefore, the selection of pv inverters should be compared as much as possible, and the products with higher overall efficiency should be selected.

4. Starting performance

The pv inverter should ensure reliable start under rated load. The high-performance pv inverter can achieve multiple full-load starting without damaging the power switching device and other circuits. For their own safety, small inverters sometimes adopt soft start or current limiting start measures or circuits.