How does the power grid quality affect the life of the frequency converter?
In the workshop, the inverter will be used on different loads, and different loads have different effects on the inverter itself.
In shock loads such as welding machines, electric arc furnaces, rolling mills, etc., the voltage often flickers. At this time, the harmonics generated by the frequency converter will seriously pollute the quality of the power grid, and also have a considerable destructive effect on the equipment itself, ranging from being unable to continue normal operation to causing damage to the input circuit of the equipment. This will have a serious impact on the life of the product
⑴In shock loads such as electric welding machines, electric arc furnaces, rolling mills, etc., it is recommended that users add reactive power static compensation devices to improve power factor and quality of the power grid.
⑵ In workshops where frequency converters are relatively concentrated, it is recommended to adopt centralized rectification and DC common bus power supply. It is recommended that users adopt 12-pulse rectification mode. The advantages are small harmonics and energy saving, especially suitable for frequent starting and braking, where the motor is in both electric operation and power generation operation.
(3) A passive LC filter is installed on the input side of the frequency converter to reduce input harmonics and improve power factor with high reliability and good effect.
⑷ An active PFC device is installed on the input side of the inverter, the effect is the best, but the cost is relatively high.
These methods can help the frequency converter fully prolong its service life.