Improved efficiency determination for a PLL-controlled series resonant inverter for induction metal surface hardening

In this paper, an improved efficiency evaluation approach is proposed and described for a controlled Series Resonant Inverter for induction surface metal hardening using phase locked loop technique. This efficiency is assessed at the induction coil side, through the heat power being transferred to the work-piece, by monitoring the temperature evolution at the metal surface during the hardening process. In addition, its impact is examined by measurement of the hardness of the work-piece made out of 1038h (AISI/SAE). Further, an efficient digital control technique was designed, implemented and integrated into the induction heating system in the range of 1kW power range, at an operating frequency of 6.4 to 7.1 kHz. Its features are flexibility, low cost hardware, and higher response time. Also, the experimental results are presented to show the validity of the simulation model, and to evaluate the system performances.

[1]  Ha Pham Ngoc,et al.  Phase Angle Control of High-Frequency Resonant Currents in a Multiple Inverter System for Zone-Control Induction Heating , 2011, IEEE Transactions on Power Electronics.

[2]  C. Bocchiola,et al.  Modelling and design of the half-bridge resonant inverter for induction cooking application , 2006, 2006 14th Mediterranean Conference on Control and Automation.

[3]  J. Acero,et al.  Resonant Inverter Topology for All-Metal Domestic Induction Heating , 2007, 2007 IEEE International Symposium on Industrial Electronics.

[4]  Enrique Maset,et al.  Improving the Efficiency of IGBT Series-Resonant Inverters Using Pulse Density Modulation , 2011, IEEE Transactions on Industrial Electronics.

[5]  C. Koompai,et al.  Asymmetrical control with phase lock loop for induction cooking appliances , 2008, 2008 5th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology.

[6]  Sumate Naetiladdanon,et al.  A power control of three-phase converter with AVFSVC control for high-power induction heating applications , 2014, IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society.

[7]  Xintian Shi,et al.  Design of low phase noise low power CMOS phase locked loops , 2008 .

[8]  Nabil A. Ahmed,et al.  High-Frequency Soft-Switching AC Conversion Circuit With Dual-Mode PWM/PDM Control Strategy for High-Power IH Applications , 2011, IEEE Transactions on Industrial Electronics.

[9]  Jun Xu,et al.  Modeling and simulation of an improved PLL-controlled circuit for series resonant inverter , 2008, 2008 International Conference on Electrical Machines and Systems.

[10]  Javad S. Moghani,et al.  Tunable Self-Oscillating Switching Technique for Current Source Induction Heating Systems , 2014, IEEE Transactions on Industrial Electronics.

[11]  S. Kittiratsatcha,et al.  Switching Frequency Control based on Phase-locked Loop for a Current-fed Parallel Resonant Inverter , 2007, 2007 Power Conversion Conference - Nagoya.

[12]  Anil Kishore Saxena,et al.  Comparison of temperature coefficient of standard inductor by measuring change in inductance and resistance , 2010, CPEM 2010.

[13]  Diego Puyal,et al.  Load-Adaptive Control Algorithm of Half-Bridge Series Resonant Inverter for Domestic Induction Heating , 2009, IEEE Transactions on Industrial Electronics.

[14]  N. S. Bayindir,et al.  DSP-based PLL-controlled 50-100 kHz 20 kW high-frequency induction heating system for surface hardening and welding applications , 2003 .

[15]  J. Burdío,et al.  Temperature Influence on Equivalent Impedance and Efficiency of Inductor Systems for Domestic Induction Heating Appliances , 2007, APEC 07 - Twenty-Second Annual IEEE Applied Power Electronics Conference and Exposition.