The frequency converter is mainly used in the variable frequency air compressor, and the main reason why the price of the variable frequency air compressor is higher than that of the ordinary power frequency machine is that the difference between the frequency converter and the host is increased, and the frequency converter accounts for the majority of the two. Therefore, whether it is to choose a variable frequency air compressor or to add a frequency converter in the energy-saving transformation, the choice of the frequency converter is very particular, and the users of the transformation need to choose different frequency converters according to the actual motor power. Today, Xiaobian will take you to understand what problems you need to pay attention to when choosing a frequency converter for different types of air compressors.
1. Selection of load type and inverter. The air compressor inverter cannot be used normally under any circumstances, so it is necessary to have a better understanding of the load, environmental requirements and the inverter. The load carried by the motor is different, and the requirements for the inverter are also different.
(1) Fan and water pump: This is the most common load, and the requirements for the inverter of the air compressor are the simplest, as long as the capacity of the inverter is equal to the capacity of the motor.
(2) Lifting load: The characteristic of this type of load is that it has a great impact when starting, so the inverter is required to have a certain margin. At the same time, when under heavy objects, there will be energy feedback, so a braking unit or a shared bus 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 mixers.
2. For long-term low-speed running, due to the high heat generation of the motor and the reduced cooling capacity of the fan, it is necessary to increase the reduction ratio or use a 6-level motor to make the motor run at a higher frequency.
3. The installation site of the inverter must meet the requirements of the standard environment, otherwise it will easily cause failure or shorten the service life. The distance between the air compressor inverter and the driving motor is generally not more than 50m. If a longer distance is required, the carrier wave needs to be reduced. frequency or increase the output reactor option for normal operation.