Multi Half Bridge LLC Resonant Inverter for Induction Hardening

Authors

  • Jirapong Jittakort -
  • Saichol Chudjuarjeen
  • Jirapong Jittakort Faculty of Industrial Education, Department of Electrical Engineering, Rajamangala University of Technology Thanyaburi
  • Apinan Aurasopon Faculty of Engineering, Mahasarakham University, Mahasakham, Thailand
  • Samart Yachiangkam Rajamangala University of Technology Lanna

DOI:

https://doi.org/10.37936/ecti-eec.2026243.264545

Abstract

A multi half-bridge LLC resonant inverter with three induction coils is used to harden metal workpieces in this research. The system operates at 80–100 kHz and outputs 3 kW of power, based on to load variations. Power is controlled through changing the duty cycle of each inverter module's output voltage waveform and a phase-locked loop for frequency tracking. This method allows soft-switching and improves system efficiency. Stable operation and improved performance demonstrate that proposed system is suitable for induction hardening. The multi-inverter design improves power distribution, system dependability, flexibility, and scalability for many industrial applications.

Downloads

Download data is not yet available.

Author Biographies

Jirapong Jittakort, Faculty of Industrial Education, Department of Electrical Engineering, Rajamangala University of Technology Thanyaburi

39 Moo 1, Khlong Hok Subdistrict, Khlong Luang District, Pathum Thani 12110, Thailand.

Apinan Aurasopon, Faculty of Engineering, Mahasarakham University, Mahasakham, Thailand

 Mahasakham, Thailand 

Samart Yachiangkam, Rajamangala University of Technology Lanna




128 Huay Kaew Road, Muang, Chiang Mai, Thailand, 50300

References

R. Kawashima, T. Mishima and C. Ide, "Three-Phase to Single-Phase Multiresonant Direct AC–AC Converter for Metal Hardening High-Frequency Induction Heating Applications," IEEE Transactions on Power Electronics, vol. 36, No. 1, pp. 639-653, 2021.

V. Esteve, J. José, J. D. Enrique, S. K. Esteban, J. M. Pedro, M. Enrique, and G. David, "Optimal LLC Inverter Design With SiC MOSFETs and Phase Shift Control for Induction Heating Applications," IEEE Transactions on Industrial Electronics, vol. 69, No. 11, pp. 11100-11111, 2022.

D. J. Kim and C. H. Ahn, "Experimental Validation of Induction Heating as an Energy-Efficient Solution for Concrete Curing," IEEE Access, vol. 13, pp. 79237-79246, 2025.

A. Mendi-Altube, I. Villar, C. Carretero and J. Acero, "Reduced-Order Dynamics of a DC-Bus Voltage-Regulated Inverter for Steel Hardening Beyond Curie Point Temperature," IEEE Transactions on Industry Applications, vol. 61, No. 4, pp. 6581-6592, 2025.

B. Meziane and H. Zeroug, "Comprehensive Power Control Performance Investigations of Resonant Inverter for Induction Metal Surface Hardening," IEEE Transactions on Industrial Electronics, vol. 63, No. 10, pp. 6086-6096, 2016.

R. Emamalipour and J. Lam, "A Multi-Mode Full-Bridge/Modified-Stacked- Switches Structured CLLC Resonant Converter for Energy Storage Applications," IEEE Transactions on Power Electronics, vol. 39, No. 5, pp. 5967-5981, 2024.

Q. Yang, M. Fujun, Z. Zhengxiao, W. Junpan, H. Gelin, F. Rui, L. Quanjie and T. Zhiheng, "A Full-Range ZVS Comprehensive Control Strategy for Dual-Port LLLC Induction Heating System," IEEE Transactions on Power Electronics, vol. 40, No. 10, pp. 14881-14893, 2025.

A. Ray and K. Rajashekara, "Design and Evaluation of a High Current Gain Resonant Inverter for Subsea Electrical Heating," IEEE Transactions on Industry Applications, vol. 58, No. 4, pp. 5093-5103, 2022.

P. Rehlaender, O. Wallscheid, F. Schafmeister and J. Böcker, "LLC Resonant Converter Modulations for Reduced Junction Temperatures in Half-Bridge Mode and Transformer Flux in the On-the-Fly Morphing Thereto," IEEE Transactions on Power Electronics, vol. 37, No. 11, pp. 13413-13427, 2022.

B. Salvi, S. Porpandiselvi and N. Vishwanathan, "An Inverter Circuit Configuration Suitable for Vessels of Different Material for Multiload Induction Cooking Application," IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 11, No. 3, pp. 3223-3235, 2023.

M. Aoyama, W. Thimm, M. Knoch and L. Ose, "Proposal and Challenge of Halbach Array Type Induction Coil for Cooktop Applications," IEEE Open Journal of Industry Applications, vol. 2, pp. 168-177, 2021.

Y. Duan, P. Ge, H. Xu and H. Lin, "An Improved Minor Loop Gain Criterion and Stability Estimation for Multi-Inverters Paralleled System," CPSS Transactions on Power Electronics and Applications, vol. 9, No. 4, pp. 416-429, 2024.

B. Qin, Y. Xu, C. Yuan and J. Jia, "A Unified Method of Frequency Oscillation Characteristic Analysis for Multi-VSG Grid-Connected System," IEEE Transactions on Power Delivery, vol. 37, No. 1, pp. 279-289, 2022.

Downloads

Published

2026-09-29

How to Cite

Jittakort, J., Chudjuarjeen, S., Jittakort, J., Aurasopon, A., & Yachiangkam, S. (2026). Multi Half Bridge LLC Resonant Inverter for Induction Hardening. ECTI Transactions on Electrical Engineering, Electronics, and Communications, 24(3). https://doi.org/10.37936/ecti-eec.2026243.264545

Issue

Vol. 24 No. 3 (2026): Articles in Press, Pre-proof - Regular Issue (October)

Section

Power Electronics

Categories

License

Copyright (c) 2026 Jirapong Jittakort, Corresponding Author, First Author, Co-authors, Samart Yachiangkam

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

This journal provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge.

- Creative Commons Copyright License

The journal allows readers to download and share all published articles as long as they properly cite such articles; however, they cannot change them or use them commercially. This is classified as CC BY-NC-ND for the creative commons license. 

- Retention of Copyright and Publishing Rights

The journal allows the authors of the published articles to hold copyrights and publishing rights without restrictions.