Power Quality Measurement for Line Frequency Coreless Induction Furnaces in MV Network

This paper presents a study about power quality problems generated by line frequency coreless induction furnaces. We analyzed a furnace with 12.5 t capacity of cast-iron. The measurements have been made in the primary of the furnace transformer, on the MV line, using the CA8334 three-phase power quality analyser. Experimental results emphasized the presence of harmonics and interharmonics in the phase voltages and harmonics in the currents absorbed from the MV network. Further to harmonic analysis of the measured signals, we have been proposed some optimization methods for operation of analyzed furnace, in such way to comply with the European norms of Electromagnetic Compatibility (EMC).