Harmonics Suppression of AC Source Current of a Single Phase Source Fed Induction Heating System

Any high frequency Induction heating system while undergoing through very high frequency switching operations, produces Electromagnetic Interference (EMI) noises or very high frequency harmonics within the system. These high frequency EMI noises conductively propagate towards the input AC source and distort the sinusoidal input AC current and make it non-sinusoidal. The desired performance from the induction heating cannot be anticipated. As such, it is inevitable to eliminate such EMI noises from the input AC source current to get the desired performance. Here, a specially designed ring type LC low pass passive filter is proposed which can accomplish to suppress these high frequency EMI noises up to satisfactory level and can restore the sinusoidal shape in the input AC source current waveform and thus improves the power quality of the AC supply for the induction heating system. The impact of the induction heating system without and with incorporating the proposed filter will be compared in this study.