On Reduction of Voltage Harmonics in Induction-Heating Devices with Power Supply from a Transistor Frequency Converter

When connecting electrothermal equipment and other nonlinear sources with voltage converters to industrial networks, the occurrence of low and high-frequency conducted disturbance is possible. The problems caused by this mostly have to be solved under factory conditions through monitoring and suppression of disturbance. Experimental studies of induction-heating units with VGT series power supplies have demonstrated the necessity of using disturbance suppression devices for them. This article presents a study of voltage waveform distortion, voltage harmonics, and high-frequency conducted disturbance in the network when connecting an induction unit with a VGT 8-60/66 series transistor power supply equipped with a passive LC filter. The efficiency of its use compared to previously manufactured units is shown. The obtained results allow a deeper understanding of existing problems and outline further ways to solve emerging challenges in the design of induction units with high-frequency transistor power supplies.