Inverter technology has a lot of inductive loads in energy saving irreplaceable position , saving energy can sometimes reach more than 30% , benefits are substantial . However , the attendant side harmonics problems are more and more attention each inverter users and the electricity sector . Since the rectifier inverter is generally not controllable phase full-wave rectifier , a DC circuit uses a large capacitor as a filter . Thus, although the network side of the inverter input voltage waveform is essentially a sine wave , but the input current is pulsed charging current , rich in harmonics , and in the network side has 5,7,11,13,15,17 , 19th harmonic currents to 5,7 times the maximum generally dominated . Sensitized load in operation to consume large amounts of reactive current , but the harmonic reactive power compensation device will not function properly , resulting in a number of modern and sophisticated control the machine can not run , so take harmonic control measures on the use of the inverter system is necessary. My company for the inverter harmonic features, design a dedicated high and low pressure filter can effectively filter out harmonics generated by the inverter device while the system is effective reactive power compensation, to use the drive to meet the majority of user needs.