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Fig. 10. Inverter Voltage Waveform
Fig. 11. Variable Workpiece Resistance for IH System
Fig. 9. The XOR Waveform (a) at resonance frequency 51.3 cording to Jury’s Stability test, the system shows good stability
kHz (b) at a frequency below resonant frequency 40 kHz level where the value of integral stability gain Kc lies between
(0 to 40×10-6).
effectiveness of using the simplified PLL controller is clear by
not effect on the efficiency for both topologies. The simulation The article also included a comparison made between
results obtained agree with the mathematical analysis obtained two IH systems with a conventional full bridge inverter and a
in section IV. reduced switch five-level inverter. It shows that the reduced
switch five-level IH system perform better than the full bridge
in term of THD, while the overall efficiency of the full bridge
is higher than the reduced switch five-level inverter with the
IH system.
VII. CONCLUSION CONFLICT OF INTEREST
In this paper, a PLL-based approach has been used to track the The authors have no conflict of relevant interest to this article.
resonance frequency and also to achieve soft switching for the
induction heating system. The adopted inverter power supply REFERENCES
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