A Study On Restraint Of Induction Heating Source’s Harmonic Current

Induction heating is a heating method which heats by the eddy current heat effectaccording to the electromagnetic induction law. It belongs to non-contact heating. Inductionheating source is a rectification-contravariant system. Mid-frequency source is acquired byrectifying power frequency source and inverting, but much harmonic current is gained by theprocess. Serious harmonic current has a severe influence on the reliability of electric powersystem and normal operation of power consumption equipment. So engineers attach greatimportance on the harmonic restraint of induction heating source. After analysing the features ofinduction heating source’s structure and harmonic current，this paper turn to add APF functioninto DCR controller to fight against harmonic by the contrast test between APF and PPF. Thispaper designs hardware and software for APF’s harmonic current examination system.To design APF, we should define an examination algorithm. This paper chooses ip-iqalgorithm based on the instant reactive power theory as examination algorithm through theoryanalysis and simulation. Compared with other algorithms, ip-iqalgorithm has the advantages onarithmetic speed and accuracy. PLL is an important part of the hardware system as the lockingspeed and accuracy influence the examination accuracy directly. This paper introduces the designof PLL at length. The digital filter has a great significance when design the software system. Thispaper uses the butterworth filter as the digital filter and obtain good performance after comparingwith some other ones.