Precautions for the use of inverters for livestock fans

In recent years, in the practical engineering application of animal husbandry fans, for the variable speed use of speed regulating fans, the application of voltage regulation and variable speed of single-phase asynchronous motors has gradually changed to the application of variable frequency speed regulation of three-phase asynchronous motors. The use of frequency converters for speed regulation of three-phase asynchronous motors has many advantages, in particular, it can improve the power factor of the motor in actual operation, more energy-saving under low-speed operation, and more accurate fan speed regulation. Low. However, due to the particularity of the speed regulation principle of the frequency converter, especially the high-frequency carrier modulation for the output, if it is used improperly in actual use, some inexplicable faults and problems will often occur, and even damage to the fan motor. Due to space limitations, this paper only provides some suggestions for the problems that need attention in practical applications, and does not involve the relevant motor drag and inverter theory and principles.

When using the inverter, the low frequency of the livestock fan should not be lower than 30HZ, and the lower frequency limit should be set in the inverter. When the fan is running at 30HZ, that is, 60% speed, the 25Pa air volume is usually the percentage of the air volume under 50HZ full speed operation to 35 to 40%, which can basically meet the demand. For specific air volume data, please refer to the fan frequency conversion of the fan manufacturer. Speed test data. When the air volume at 30HZ still cannot meet the requirements, it is necessary to replace the fan with a smaller air volume. Usually, the fan for livestock breeding is equipped with an asynchronous motor with an isolation grade of F class, which will not cause problems when used above 30HZ, but when it is used below 30HZ, the life of the motor will be reduced, and the motor will be damaged quickly even under lower frequency operation.