An Improved PIλ Controller for Resonant Inverter Induction Heating Systems under Load and Line Variations
M. Helaimi, M. Benghanem, B. Belmadani
Dept. of Electrical Engineering, University Hassiba Ben Bouali
2 Dep. of Automatic Control, University of Mohamed Boudhiaf
Dept. of Electrical Engineering, University Hassiba Ben Bouali
Abstract: This paper presents the description, analysis and control of an LLC resonant inverter suitable for induction heating applications. The output power of the proposed inverter has to be controlled by adjusting the duty cycle of the switches using a power loop circuit based on fractional order PI? controller. A phased locked loop (PLL) is used as frequency tracking control circuit. The complete closed loop control model is obtained using small signal analysis. The validity of the proposed control is verified by simulation results. Results of this simulation are compared to those obtained by using a PI controller. They show that the improved PI? controller exhibits a much better behaviour.
Keywords: Robustness, LLC resonant inverter, small signal model, improved PI? controller, induction heating system.
CITE THIS PAPER AS:
M. HELAIMI, M. BENGHANEM, B. BELDAMANI, An Improved PIλ Controller for Resonant Inverter Induction Heating Systems under Load and Line Variations, Studies in Informatics and Control, ISSN 1220-1766, vol. 21 (4), pp. 423-430, 2012. https://doi.org/10.24846/v21i4y201208
Nowadays, resonant topologies are used in a number of industrial applications, including power supplies for induction heating systems. LLC is being a more popular topology because it has the desirable characteristics of the series and parallel ones -.
In control practice, fractional order PIλ controllers have been successfully applied to a wide variety of engineering problems -, including DC-DC converters .
Several research works on control theory reveal that the design of the PIλ controller is not easy when the system is difficult to model due to complexity, non linearity, or when the resource of information are inexact. LLC resonant inverters fall into this category because they have a time varying structure and contain elements that are non linear.
In this paper, we propose an effective control system for LLC resonant inverter which uses variable frequency and variable duty cycle. The output power of the proposed inverter has to be controlled by adjusting the duty cycle of the switches using power loop circuit based on fractional order PIλ controller. A PLL is used as frequency tracking control. In this case, a stability and small signal dynamic performance can be assessed using linear control techniques and the small signal model of the LLC resonant inverter.
The organization of this paper is as follows: he proposed inverter circuit configuration and the detailed control system architecture are given in Sections II and III. Closed loop system design and parameter tuning of the proposed PIλ controller are presented in Sections IV. Conclusion is given in Section V.
- Chudjuarjeen, S., A. Sangswang, C. Koompai, An Improved LLC Resonant Inverter for Induction-Heating Applications with Asymmetrical Control, IEEE Transactions on Industrial Electronics, vol. 58(7), July 2011, pp. 2915-2925.
- Chudjuarjeen, S., V. Hathairatsiri, Series and Parallel Resonant Inverter for Induction Heating application, International Conference on Science, Technology and Innovation for Sustainable Well-Being (STISWB), 23-24 July 2009, Mahasarakham University, Thailand.
- Kelemen, A., N. Kutasi, Lyaponov-based Frequency Shift Power Control of Induction Heating Converters with Hybrid Resonant Load, Acta Universitatis Sepientiae, 2009, pp. 41-52.
- Epsi, J., E. Dede, R. G. Gil, J. C. Moreno, Design of the L-LC Resonant Inverter for Induction Heating based on its Equivalent SRI, IEEE Transactions on Industrial Electronics, vol. 54, No. 6, December 2007, pp. 3178-3187.
- Chudjuarjeen, S., A. Sangswang, C. Koompai, LLC Resonant Inverter for Induction Heating with Asymmetrical Voltage-Cancellation Control, in Proc. IEEE Int. Symp. Circuits Syst., Taipei, Taiwan, May 2009, pp. 2874–2877.
- Mansouri, R., S. Djenoune, M. Bettayeb, Fractional I-P Pole Placement Controller Design: Application To Permanent Magnet Synchronous Motor Control, Int. J. Modelling, Identification and Control, vol. 4, N°2, 2008, pp. 176-185 [Online].
- Bettou, K., A. Charef, Control Quality Enhancement Using Fractional PIλDμ Controller, Int. Journal of Sciences and Systems, vol. 40, No.8, August. 2009, pp. 875-888.
- Podlubny, I., Fractional Order Systems and Fractional Order Controllers, Inst. Exp. Phys., Slovak Acad. Sci., Vol.4, No.2, 1994, pp.28-34.
- Charef A., Analogue Realization of Fractional Order Integrator, Differentiator and Fractional PIλDμ, IEEE Proceeding on Control Theory Applications, vol. 54, No.5, 2006, pp. 714-720.
- Fonseca, N. M., J. A. Tenreiro, Fractional-order hybrid control of Robotic Manipulators. In 11th Intl. conference on advanced robotics, Coimbra, Portugal, 2003, pp. 393-398.
- Laroche, E., D. Knittel, An Improved Linear Fractional Model for Robustness Analysis of a Winding System, Control Engineering Practice, 13(5), 2005, pp. 659-666.
- Petras, I., B. M. Vinagre, L. Dorcak, V. Feliu, Fractional Digital Control of a Heat Solid: Experimental Results, In International Carpathian control conference, Malenovice, Czech Republic, 2002, pp. 365-370.
- Monje, C. A., B. M. Vinagre, V. Feliu, Y. Q. Chen. Tuning and Auto-Tuning of Fractional Order Controllers for Industry Applications, Control Engineering Practice 16, 2008, pp. 798-812.
- Calderon, A. J., B. V. Vinagre, V. Feliu, Buck-Boost Converter with Fractional Control of Electric Vehicles, International Conference on Renewable Energies and Power Quality, Granada Spain, 23rd to 25th March, 2010.
- Ahmed, N. A., Three-phase High Frequency AC Conversion Circuit with Dual Mode PWM/PDM Control Strategy for High Power IH Applications, PWASET Vol. 35, November 2008, pp. 371-377.
- Lucía, O., J. M. Burdio, I. Millán, J. Acero, D. Puyal, Load-adaptive Algorithm of Half-bridge Series Resonant Inverter for Domestic Induction Heating, IEEE Transactions on Ind. Electron., vol. 56, No. 8, Aug. 2009, pp. 3106–3116.
- Tian, J., J. Petzoldt, T. Riemann, M. Scherf, G. Berger, Control System Analysis and Design of a Resonant Inverter with the Variable Frequency Variable Duty Cycle Scheme, European Conference on Power Electronics and Applications, 2005, Dresden, Germany.
- Lucía, O., J. M. Burdio, I. Millán, J. Acero, L. A. Barragán, Efficiency oriented Design of ZVS Half-bridge Series Resonant Inverter with Variable Frequency Duty Cycle Control, IEEE Trans. Power Electron., vol. 25, No. 7, Jul. 2010, pp. 1671-1674.
- Kamli, M., S. Yamamoto, M. Abe, A 50-150Khz Half-bridge Inverter for Induction Applications, IEEE Transactions on Industrial Electronics, vol. 43, No.1, Feb. 1996, pp. 163-172.
- Yang, E. X., F. C. Lee, M. M. Jovanovic, Small Signal Modeling of Power Electronic Circuits using Extended Describing Function Technique, in Proc. VPEC, 1991, pp. 167-178.
- Martin-Ramos, J. A., J. Diaz, A. M. Pernia, J. M. Lopera, F. Nuno, Dynamic and Steady State Models for the PRC-LCC Resonant Topology with a Capacitor as Output Filter, IEEE Transactions on Industrial Electronics, vol 54, No.4, August 2007, pp. 2262-2274.
- GRAJALES, L., F.,C. LEE, Control system Design and Small Signal Analysis of a Phase Shift Controlled Series Resonant Inverter for Induction Heating, in PESC Record- IEEE Power Electronics Specialists Conference, 1995, pp. 450-456.
- TIAN, J., J. PETZOLDT, T. REIMANN, M. SCHERF, G. BERGER, Modelling of Asymmetrical Pulse Width Modulation with Frequency Tracking Control using Phasor Transformation for Half-Bridge Series Resonant Induction Cookers, 11th European Conference on Power Electronics and Applications (EPE), September, 2005, Dresden, Germany.
- GAO, Z., X. LIAO, Improved Oustaloup Approximation of Fractional-order Operators using Adaptive Chaotic Particle Swarm Optimization, Journal of Systems Engineering and Electronics, Vol. 23, No. 1, Feb. 2002, pp. 145-153.
- KRISTIANSSON, B., B. LENNARSTON, Robust and Optimal Tuning of PI and PID Controllers, IEE Proceedings of Control and Applications, Vol. 149, No. 1, 2002, pp. 17-25.