Harmonic filter design and installation: a case study with resonance

A new set of induction furnaces to be installed in an expansion to a major foundry located in Alabama was specified to produce harmonic injection into the industrial power system. The furnaces, which alone were in compliance with IEEE-519, produced an 11th harmonic current injection. The power factor correction capacitors, located at the point of common coupling to the utility, and the utility impedance were resonant near this harmonic. This paper documents the approach utilized in treating this problem and provides results from the installation.