Paper mill air compressor unit variable frequency control device

The utility model discloses a paper mill air compressor unit variable frequency control device belongs to equipment energy -saving control technical field. It includes two or above air compressor machine, converter, PLC controller and gas holder, the parallelly connected back of gas transmission pipeline and the gas tank connection of air compressor machine, and the gas holder is connected to gas appliances by the outlet duct, the power return circuit of air compressor machine motor includes the first loop and second return circuit, and wherein the first loop is connected to the power cord through first switch, converter, and second switch lug connection to power cord is passed through in the second return circuit, the output nodes of PLC controller is connected to the control coil of first switch and second switch respectively, through switch -on and disconnection control coil, realizes the power frequency of air compressor machine motor and the automatic switch -over between the variable frequency operation