Shunt active power filter implementation for induction heating applications

This paper presents the prototype implementation of a 140 kVA shunt active power filter (APF) for current harmonics and fundamental reactive power compensation of a 200 kW induction heating system using a front-end controlled rectifier. Implementation issues regarding the power system and also have the digital control are addressed and discussed. The APF control algorithm has been implemented on a 16-bit, fixed-point, industrial digital signal processor (DSP) controller. The current control is based on proportional - sinusoidal signal integrators (P-SSIs), able to provide good performance in current harmonic elimination and power factor compensation. The experimental tests, performed in real industrial environment for a 200 kW induction heating plant, show good results.