SIMULATION STUDY OF TRANSIENT CURRENT LIMIT CONTROL FOR INDUCTION HEATING

Abstract

This study proposes a transient current limit control scheme for induction heating based on the study of transient current level control of a 4KW 10KHz VSI fed Induction Furnace during start-up current surge. The furnace was characterized and generated parameters were converted to per unitized values for simulation and study. This generalized model makes any chosen method applicable to induction heating schemes of the series parallel configuration. Three current control schemes are experimented. A comparison of the Methods 1,2 and 3 on the bases of over current limiting capability, heat delivery efficiency and integrity of steady state waveform viz-a-viz the uncontrolled VSI steady state output wave form was made. The Method 3 which was chosen gave a high fidelity replication of the uncontrolled VSI waveform after only five transient cycles with only 0.45% steady-state amplitude error.