Frequency converters are mainly used in frequency conversion air compressors, and the main reason why the price of frequency conversion air compressors is higher than that of ordinary industrial frequency machines is the increase of frequency converters and the difference of the host, and frequency converters account for the bulk of the two. Therefore, whether it is choosing a variable-frequency air compressor or adding a frequency converter in the energy-saving transformation, the selection of the frequency converter is very particular. The users of the transformation need to choose different frequency converters according to the actual motor power. Today, the editor will take you to understand what issues need to be paid attention to when choosing inverters for different types of air compressors.
1. Selection of load type and inverter. Air compressor inverters can not be used normally under any circumstances, so it is necessary to have more understanding of the load, environmental requirements and inverters. The load carried by the motor is different, and the requirements for the inverter are also different.
(1) Fans and pumps: These are the most common loads, and the requirements for the air compressor frequency converter are the simplest, as long as the capacity of the frequency converter is equal to the capacity of the motor.
(2) Lifting load: This type of load is characterized by a large impact when starting, so it requires a certain margin for the inverter. At the same time, there will be energy feedback when under heavy objects, so a braking unit or a shared bus method should be used.
(3) Uneven load: Some loads are sometimes light and sometimes heavy. At this time, the capacity of the air compressor inverter should be selected according to the heavy load, such as rolling mill machinery, crushing machinery, and mixer.
2. Long-term low-speed rotation, because the motor generates higher heat and the cooling capacity of the fan is reduced, it is necessary to increase the reduction ratio or switch to a 6-level motor to make the motor run near a higher frequency.
3. The installation location of the frequency converter must meet the requirements of the standard environment, otherwise it will easily cause malfunctions or shorten the service life. The distance between the air compressor frequency converter and the drive motor is generally not more than 50m. If a longer distance is required, the carrier wave must be reduced. Frequency or increase the output reactor option to operate normally.