In this paper the power control behaviour of a high frequency induction heating system is analyzed with different fixed frequency control schemes. The control schemes are mainly phase-shift control (PSC), asymmetrical voltage cancellation control (AVC) and pulse density modulation control (PDM) respectively. Moreover, hybrid control schemes like PDM-PSC and PDMAVC control schemes are also applied to obtain better power control after suppressing the disadvantages of individual control schemes. The induction heating system consists of a dual output full bridge high frequency resonant inverter. The average output power can be adjusted by varying the output voltage waveform, which achieves the zero-voltage switching (ZVS) condition and reduces the power losses on the insulated-gate-bipolar transistor (IGBT) switches and improves the efficiency over a wide power range. Later the results obtained under the five control schemes are compared. The complete analysis is realized and implemented using the power system simulator (PSIM) environment.

Keywords: Full-bridge inverter, Insulated-gate-bipolar transistor (IGBT), Phase-shift-control (PSC), Asymmetrical-voltagecancellation (AVC), Pulse-density-modulation(PDM), Power-system-simulator (PSIM), Duty cycle