Study of the suitable value of dead-time between control signals of transistors for a series-resonant inverter with phase-shift control in induction heating systems

Abstract

Induction heating provides contactless, energy-efficient, accurate, and fast heating of electrically conductive materials. Due to its advantages, IH is increasingly used in different fields such as industry, medicine, and the household sector. High-frequency transistor converters for the induction heating system are often based on series-resonant inverters. This paper analyzes a phase-shift-controlled voltage-source series-resonant inverter for induction heating systems. Mathematical analysis was performed in order to obtain the expressions that describe the output current of the phase-shift-controlled series-resonant inverter in the steady-state mode. Based on the analysis and the obtained expressions of the output current, analytical expressions of the dead-time between the transistors’ control signals of the SRI are obtained. The analytical expressions for determining the value of the dead-time are obtained for two cases: 1) zero value of the phase-shift; 2) the phase shift is greater than zero. To verify the obtained analytical expressions of the output current, validation was performed in the MATLAB/Simulink environment by comparing the peak current values. The verification showed the high accuracy of the obtained expressions, the deviation between the calculated and simulated values of the peak current is less than 0.1 %. The made simplifications of the dead-time expressions also were verified by calculation, the deviation between the calculated values of the drain-to-source voltage at the end of the commutation and the expected value is no more than 3.6 %. The SRI prototype has been designed and implemented in order to validate the analytical and simulation results