Advanced
Buck-Boost Interleaved Inverter Configuration for Multiple-Load Induction Cooking Application
Buck-Boost Interleaved Inverter Configuration for Multiple-Load Induction Cooking Application
Journal of Electrical Engineering and Technology. 2015. Jan, 10(1): 271-279
Copyright © 2015, The Korean Institute of Electrical Engineers
This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/3.0/)which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
  • Received : June 22, 2014
  • Accepted : September 24, 2014
  • Published : January 01, 2015
Download
PDF
e-PUB
PubReader
PPT
Export by style
Article
Author
Metrics
Cited by
TagCloud
About the Authors
P Sharath Kumar.
Corresponding Author: Dept. of Electrical Engineering, National Institute of Technology Warangal, India. (sharathpapani@nitw.ac.in)
N Vishwanathan.
Dept. of Electrical Engineering, National Institute of Technology Warangal, India
Bhagwan K. Murthy
Dept. of Electrical Engineering, National Institute of Technology Warangal, India

Abstract
Induction cooking application with multiple loads need high power inverters and appropriate control techniques. This paper proposes an inverter configuration with buck-boost converter for multiple load induction cooking application with independent control of each load. It uses one half-bridge for each load. For a given dc supply of V DC , one more V DC is derived using buckboost converter giving 2V DC as the input to each half-bridge inverter. Series resonant loads are connected between the centre point of 2 V DC and each half-bridge. The output voltage across each load is like that of a full-bridge inverter. In the proposed configuration, half of the output power is supplied to each load directly from the source and remaining half of the output power is supplied to each load through buck-boost converter. With buck-boost converter, each half-bridge inverter output power is increased to a full-bridge inverter output power level. Each half-bridge is operated with constant and same switching frequency with asymmetrical duty cycle (ADC) control technique. By ADC, output power of each load is independently controlled. This configuration also offers reduced component count. The proposed inverter configuration is simulated and experimentally verified with two loads. Simulation and experimental results are in good agreement. This configuration can be extended to multiple loads.
Keywords
1. Introduction
Induction cooking is one of the several applications of induction heating. Induction heating method is a far better approach than other conventional methods. In conventional methods, the heat is transferred from heat source to load by conduction or radiation. In induction heating, the heat is developed inside the load due to generation of eddy currents at skin depth level from the surface [1] . In recent times, considerable progress is made in control schemes and inverter configurations. A typical arrangement of high frequency (HF) induction heating circuit is shown in Fig. 1 .
PPT Slide
Lager Image
Typical arrangement of high frequency induction heating resonant inverter
Resonant inverter is commonly used as a source of high frequency AC supply. The DC input to it is derived by rectifying the utility AC source. High frequency AC flowing in the load coil results in eddy currents induced in the vessel at skin depth level resulting in heating effect. The eddy currents produced in the load are concentrated in a peripheral layer at skin depth ( δ ), which is expressed as
PPT Slide
Lager Image
where, ρ is electrical resistivity, μ is magnetic permeability, μr is relative magnetic permeability of the load material, and fs is switching frequency of the inverter. Commonly used topologies for induction cooking application are quasi resonant, half-bridge, and full bridge inverters [2 - 4] . Out of these, full bridge inverter is preferred for high power applications. Half-bridge inverter is preferred for less components count. Multiple-load half-bridge series resonant inverter is shown in Fig. 2 .
PPT Slide
Lager Image
Multiple-load half-bridge series resonant inverter
In this, L r1 is the coil inductance, C r1 is the resonant capacitance, and R eq1 is equivalent resistance of the load-1. Similarly, L r2 , C r2 , and R eq2 are the coil inductance, resonant capacitance, and equivalent resistance of the load- 2 respectively. C 1 and C 2 are DC link split capacitors. Q 1 and Q 2 are the switching devices with anti-parallel diodes D 1 and D 2 of load-1 inverter circuit. Q 3 and Q 4 are the switching devices with anti-parallel diodes D 3 and D 4 of load-2 inverter circuit. V DC is the supply voltage, i 1 is the load-1 resonant tank current and i 2 is the load-2 resonant tank current.
Pulse amplitude modulation (PAM) and pulse frequency modulation (PFM) were used to control output power in induction heating application. Under PAM control, amplitude of the source voltage is varied to control the output power [5] . It requires power processing at two stages i.e., one at AC to DC power conversion and other at high frequency inverter, resulting in more complexity and reduced efficiency. Under PFM control, the switching frequency has to be varied over a wide range [6] . Also, the soft switching operating region for zero voltage switching (ZVS) operation is relatively narrow. If the circuit operates below the resonance, the filter components are large at low frequency range. In [7] , for induction heating application, phase shift control (PSC) technique is used for output power control. ZVS problem is minimized by varying the switching frequency. In [8] , phase-shifted PWM and load-adaptive PFM control strategies are used. In [9], hybrid power control technique with pulse density modulation (PDM) and phase-shift modulation (PSM) are proposed for induction heating applications. These methods improve the performance of the inverter in several aspects. ZVS problem is also minimized by techniques such as asymmetrical voltage cancellation (AVC) and asymmetrical duty cycle (ADC) control [10] . In [11] , two operating modes for power control of half-bridge resonant inverter induction heating system are described. One operating mode uses variable frequency control for larger output power. Other operating mode uses pulse density modulation control in low to medium power range. It has the advantage of high efficiency over wide output power range. The limitation is the use of variable frequency control in certain power range.
In induction cooking application, one inverter feeds power to a single load. For multiple load application, there is a need to develop inverter circuits and control techniques which can minimize components count and provide independent control of each load. Certain techniques are available in the literature. In [12] , single inverter with two load system is proposed and analyzed. It uses variable switching frequency control. This scheme has one master load and one slave load. It has several resonant capacitors connected in parallel by electro-mechanical switches. These are activated for power control. In [13] , an inverter configuration for two loads is suggested. It has three legs wherein one leg is common for both the loads. This configuration provides independent and simultaneous control of both loads. Asymmetric voltage cancellation technique is used for control of the inverters. This method has the advantage of reduced components count and better utilization of devices. This technique can be extended to more than two loads also. In [14] , two-output charge boost type induction cooking application is proposed using asymmetrical voltage cancellation technique. A power factor correction stage is also added to improve the power factor. In [15] , a load-adaptive control algorithm for variable load and large output power range is proposed and described. In the design process, aspects like efficiency, acoustic noise, and flicker emissions are considered. It is shown that single control strategy is not suitable when several aspects are to be considered. An appropriate combination of different control techniques is suggested for each power range. The limitation of this method is increased complexity in the control implementation. In [16] , a cost-effective multiple-load system is proposed. It uses discontinuous mode control to improve light-load performance. Converter efficiency is increased by reducing switching frequency while maintaining proper power factor. Switching frequency range is between 20 to 150 kHz. Variable switching frequency is the limitation of this method. In [17] , system-on-programmable chip and FPGA based test bench for multiple inductor power converter is proposed. The power converter is modelled in VHDL. This speeds-up the simulation process of the system. In [18] , multiple output induction heating system which uses direct ac-ac power conversion is proposed. This method gives higher efficiency, reduced components count and reduced complexity. This is achieved with the use of matrix converter for multiple loads. Variable frequency control may be the limitation of this method. Also, larger input harmonic currents are present under unbalanced operation.
This paper proposes buck-boost interleaved inverter configuration for induction cooking application with multiple-loads. It uses one half-bridge for each load. For a given dc supply of V DC one more V DC is derived using buck-boost converter giving 2V DC as the input to each halfbridge. Series resonant loads are connected between the centre point of 2V DC and each half-bridge. Output voltage is switched between +V DC and –V DC with half-bridge configuration. In the proposed configuration, half of the output power is supplied to each load directly from the source and remaining half of the output power is supplied frequency with ADC control technique. By ADC [9] , output power of each load is independently controlled. The proposed configuration can be extended to multipleloads. to each load through buck-boost converter. With buckboost converter, each half-bridge inverter output power is increased to a full-bridge inverter output power level. Each half-bridge is operated with constant and same switching
2. Proposed Inverter Configuration
This section describes the proposed inverter configuration for multiple-load induction cooking application. Circuit diagram of the proposed inverter is shown in Fig. 3 for two loads. Both loads use series resonant circuit. It uses one half-bridge for each load. For a given dc supply of V DC one more V DC is derived using buck-boost converter giving 2V DC as the input to each half-bridge. Due to polarity reversing nature of output voltage in buck-boost converter, it becomes possible to use input and output voltages of buck-boost converter as two dc sources like split capacitor configuration of half-bridge inverter. With suitable duty ratio of buck-boost converter, it is possible to maintain output voltage equal to input voltage (V DC ) for all induction heating loads. Hence, input and output voltages of buck-boost converter are maintained at equal magnitude. This gives total input voltage of 2V DC to each half-bridge inverter, which is also a series connection of two dc sources each of V DC . The buck-boost converter is switched at 30 kHz.
PPT Slide
Lager Image
Proposed inverter configuration for multiple-load induction cooking
Series resonant loads are connected between the centre point of 2V DC and each half-bridge as shown in Fig. 3 . The output voltage across each load switches between +V DC and –V DC with half-bridge configuration. It is similar to that of a full bridge inverter with V DC as the DC input. Hence in this proposed configuration, each load handles same power as that supplied from a full-bridge configuration. Each half-bridge is operated with constant and same switching frequency with ADC control technique. By ADC, output power of each load is independently controlled. Load-1 is connected to inverter output voltage ν AB . Load-2 is connected to inverter output voltage ν AC . Load-1 consists of C r1 , L r1 , and Req1 which are resonant capacitance, inductance and equivalent load resistance respectively making series resonant tank. Similarly, load-2 consists of C r2 , L r2 , and R eq2 , which are resonant capacitance, inductance and equivalent load resistance respectively making series resonant tank. Resonant frequencies of two load circuits are f r1 =
PPT Slide
Lager Image
and f r2 =
PPT Slide
Lager Image
respectively. If required they can be of different power ratings, but operated at same switching frequency. Hence, the resonant frequencies of both load circuits have to be same.
In this paper, both loads have same component values and their resonant frequencies are same. L r1 = L r2 = L r , C r1 = C r2 = C r , and R eq1 = R eq2 = R eq . Hence, their power rating is same and operated at a switching frequency of 30 kHz. Resonant frequency of each load circuit is, f r =
PPT Slide
Lager Image
Switching frequency of each leg is slightly higher than their resonant frequency. Hence, inverter switching frequency (f s ) can be chosen 5 to 10% higher than the resonant frequency (f r ) for ZVS operation.
Fig. 4 shows gating signals ν g1 and ν g2 for the switching devices Q 1 and Q 2 of half-bridge inverter for load-1. Also, output voltage ( ν AB ) along with its fundamental component ( ν AB1 ) is shown. The load-1 current ( i 1 ) is shown assuming it to be sine wave due to filtering of harmonics by resonant load. These waveforms are based on ADC control technique. Here, the angles θ 1 or β 1 can be used as control variables and β 1 = (180° – θ 1 ). Ø 1 is the angle between vAB1 and i 1 . β 1 can be controlled to control the duty-ratio of output voltage ( ν AB ). The duty-ratio (D 1 ) of load-1 halfbridge inverter is defined as
PPT Slide
Lager Image
PPT Slide
Lager Image
Output voltage and current with control variables with ADC control technique
In Fig. 4 , T on and T/2 are shown with gating pulses for load-1 half-bridge inverter. Analysis of asymmetrical duty cycle control for series resonant inverter is presented in [10] . Harmonics in load current waveform are negligibly small and ignored.
The amplitude of the fundamental voltage
PPT Slide
Lager Image
can be expressed in ADC control technique as,
PPT Slide
Lager Image
PPT Slide
Lager Image
is the amplitude of the load-1 current and assumed to be sinusoidal. The phase lag Ø 1 between the voltage ν AB1 and the load current i 1 can be expressed as,
PPT Slide
Lager Image
The quality factor (Q) and normalized switching frequency ( ω n ) are defined as
PPT Slide
Lager Image
PPT Slide
Lager Image
where ω s is angular switching frequency and ω r is angular resonant frequency.
The resonant tank circuit current (
PPT Slide
Lager Image
) is expressed as,
PPT Slide
Lager Image
where Ø = Ø 1
The load-1 output power can be expressed as,
PPT Slide
Lager Image
PPT Slide
Lager Image
where P o2 is output power of load-2 and θ 2 is control variable for load-2. The total output power (P T ) is expressed as P T = P o1 + P o2 . From the above equations, the amplitude of individual currents and output powers can be controlled by varying corresponding control angles θ 1 and θ 2 . As θ 1 and θ 2 can be independently controlled, both loads are independently controllable.
The output voltage across each load is like that of a fullbridge inverter. Hence the output power increases with proposed configuration. In the proposed configuration, half of the output power is supplied to each load directly from the source and remaining half of the output power is supplied to each load through buck-boost converter.
The buck-boost converter shown in Fig. 3 needs to be controlled in closed loop to maintain its output voltage equal to input voltage under different load conditions. Since, half of the load power is processed through buckboost converter, losses in buck-boost converter have to be minimized as much as possible. This helps in improving overall efficiency of the proposed configuration. For this, in place of free-wheeling diode power MOSFET (S 2 ) is used. This reduces losses during free-wheeling. Also, both MOSFETs used in buck-boost converter are of low on-state resistance.
  • For, Pin= inverter input, and PT= total inverter output
  • ηI= inverter efficiency =
  • ηB= efficiency of buck-boost converter
  • η = overall efficiency (with buck-boost converter)
PPT Slide
Lager Image
Overall efficiency is dependent on η B . For ideal buckboost converter, η B =1 and η = η I . Under practical condition, η B is less than unity. This results in η < η I .
3. Results of Proposed Inverter Configuration
Experimental setup of proposed inverter configuration is shown in Fig. 5 .
PPT Slide
Lager Image
Experimental setup of proposed inverter configuration
Proposed inverter configuration with ADC control technique is simulated and experimentally verified using the parameters shown in Table 1 .
Parameters of proposed inverter configuration for induction cooking
PPT Slide
Lager Image
Parameters of proposed inverter configuration for induction cooking
Proposed circuit of half-bridge series resonant inverter configuration for two load induction cooking application is designed and operated at a switching frequency of 30 kHz. It is for a total output power (P T ) of 135 watts with a source voltage of 15V. The simulation and experimental studies are done for different duty-ratio combinations of D 1 and D 2 . D 1 and D 2 are duty-ratios of inverter output voltages ν AB and ν AC respectively. Gate pulses, inverter output voltage waveforms and load currents for the proposed inverter configuration are shown in Figs. 6 to 9 for various dutyratio combinations.
PPT Slide
Lager Image
Inverter waveforms for D1= 0.97 and D2= 0.97
PPT Slide
Lager Image
Inverter waveforms for D1= 0.97 and D2= 0.6
PPT Slide
Lager Image
Inverter waveforms for D1= 0.7 and D2= 0.3
PPT Slide
Lager Image
Inverter waveforms for D1= 0.5 and D2= 0.3
Figs. 6(a) , 7(a) , 8(a) , and 9(a) show gate pulses ν g1 to ν g4 of switching devices Q 1 to Q 4 for various duty-ratio combinations of D 1 and D 2 . These figures also show inverter output voltages ν AB and ν AC for these duty-ratio combinations. Fig. 6(a) shows these waveforms for D 1 = 0.97 and D 2 = 0.97. Figs. 7(a) , 8(a) , and 9(a) show them for D 1 = 0.97 and D 2 = 0.6, D 1 = 0.7 and D 2 =0.3, and D 1 =0.5 and D 2 =0.3 respectively. These figures help in understanding the operation of the proposed inverter configuration. Fig. 6(b) shows the simulation waveforms of both inverter output voltages and their load currents for a duty-ratio of D 1 = 0.97 and D 2 = 0.97.
Figs. 7(b) , 8(b) , and 9(b) show them for D 1 = 0.97 and D 2 = 0.6, D 1 = 0.7 and D 2 = 0.3, and D 1 = 0.5 and D 2 = 0.3 respectively. Similarly, Fig. 6(c) shows these waveforms of inverter output voltages and their load currents under experimental condition. In Fig. 6(c) , D 1 = 0.97 and D 2 = 0.97. Figs. 7(c) , 8(c) , and 9(c) show them for D 1 = 0.97 and D 2 = 0.6, D 1 = 0.7 and D 2 =0.3, and D 1 = 0.5 and D 2 = 0.3 respectively.
From Figs. 6 to 9 , it can be observed that each output voltage waveform and its load current is independently controlled with ADC control technique. Independent control is achieved by variation of duty-ratios of individual inverters. This gives power control in each load independently.
From simulation and experimental results, it is observed that both results are in good agreement with each other. It is also seen that for a given DC input voltage of V DC , the proposed inverter configuration of half-bridge series resonant inverter has same output voltage level as fullbridge configuration. This concept can be extended for multiple-loads also. Here, all loads can be operated at same switching frequency. In Figs. 6 and 7 , duty-ratio of load-2 is 0.97 and 0.6 respectively, whereas duty-ratio of load-1 is kept constant at 0.97. It can be observed that current in load-2 varies with the variation of its duty-ratio, while the current in load-1 remains constant. Hence, current in load-2 is controlled independently. Similarly, in Figs. 8 and 9 , duty-ratio of load-1 is 0.7 and 0.5 respectively, whereas duty-ratio of load-2 is kept constant at 0.3. It can be observed that current in load-1 varies with variation of its duty-ratio while the current in load-2 remains constant. Hence, current in load-1 is controlled independently. Proposed inverter configuration gives advantage of independent power control of each load. Though each load is powered with half-bridge configuration, it has output power capability of full-bridge. Also, it reduces component count for multiple loads.
In this paper, the switching frequency used for inverters is 30 kHz. Hence, ZVS is not of much concern. If required, the inverters can be switched at higher frequencies with possibility of ZVS.
4. Independent Control of Load Power
Load power control is achieved using ADC control technique. Output powers of load-1 and load-2 are dependent on corresponding load currents. In Table 2 , load- 1 current is controlled with its duty-ratio, and load-2 current remains constant as D 2 is kept constant at 0.97.
Load-1 current with its duty-ratio
PPT Slide
Lager Image
Load-1 current with its duty-ratio
Similarly, it can be shown that when load-2 current varies with its duty-ratio and load-1 current remains constant. Each load current is controlled independently with its duty-ratio. It can be observed from Figs. 10 and 11 .
PPT Slide
Lager Image
Variation of current in load-1 vs. D1
PPT Slide
Lager Image
Variation of current in load-2 vs. D2
Variation of current in load-1 with variation of D 1 is shown in Fig. 10 . For this, D 2 is kept constant at 0.97. Under this condition, current in load-1 only varies whereas current in load-2 remains constant. Similarly, variation of current in load-2 with variation of D 2 is shown in Fig. 11 . For this, D 1 is kept constant at 0.97. Under this condition, current in load-2 only varies whereas current in load-1 remains constant. Simulation and experimental results are in good agreement with each other.
In Fig. 12 , variation of output power of load-1 vs. D 1 is shown with proposed configuration and with conventional half-bridge configuration. In the proposed configuration, output power is 4 times compared to conventional halfbridge configuration.
PPT Slide
Lager Image
Variation of output power for load-1 vs. D1
5. Overall Efficiency
Overall efficiency for the proposed configuration is shown in Fig. 13 . In Fig. 13 , output power of load-1 is controlled while that of load-2 is kept constant at its maximum. Total output power is measured by addition of individual inverter outputs. Each inverter output is computed as I 2 R eq . ‘I’ is the r.m.s current value of individual load circuit. ‘R eq ’ is the equivalent load resistance of each load. Input power is obtained by multiplication of dc input voltage (V DC ) and average current of the source. Overall efficiency includes the efficiency of buck-boost converter also. To maintain high overall efficiency, buck-boost converter also should have high efficiency. It should be taken care in design stage.
PPT Slide
Lager Image
Overall efficiency vs. D1
Both of the loads are of same power capacity. Hence, overall efficiency characteristic will be same if output power of load-1 is kept constant and that of load-2 is varied. Under full-load condition, overall efficiency is > 93%.
6. Conclusions
In this paper, buck-boost interleaved inverter configuration with half-bridge series resonant inverters for two-load induction cooking application has been proposed. In this configuration, each half-bridge inverter output power is increased to a full-bridge inverter output power level. Both loads are independently controlled. It can be extended for more than two loads also. Excluding buckboost converter, number of switching devices/load is two i.e., one leg/load. Same switching frequency is used for powering both the loads. i.e., each load is operated at same switching frequency of 30 kHz. Asymmetric duty cycle control technique is used for power control of individual loads. Under full-load condition, overall efficiency is >93%. Design and control of the proposed configuration are simple. Simulation and experimental results of the proposed configuration are in good agreement.
BIO
P. Sharath Kumar He received B.Tech degree in Electrical and Electronics Engineering from Jawaharlal Nehru Technological University, Hyderabad, India in 2006 and M.Tech degree from National Institute of Technology, Kurukshetra, India in 2008. Presently pursuing Ph.D in Electrical Engineering at National Institute of Technology, Warangal, India. His area of interest is high frequency resonant inverters.
N. Vishwanathan He received B.Sc (Engg.) degree in electrical engineering from Dayalbagh Educational Institute, Agra, India, in 1990, M.Tech. degree in electrical machines and industrial drives from REC, Warangal, India in 1992, and Ph.D. from Indian Institute of Science, Bangalore, India, in 2004. He is currently working as Professor in the Dept. of Electrical Engg, NIT, Warangal, India. His areas of interest are switched mode power conversion and induction heating applications.
Bhagwan K. Murthy He obtained his B.E. (Electrical) and M.E. (Industrial Electronics) degrees from the M. S. University of Baroda, India in 1983 and 1987, respectively. He did his PhD at IIT Madras in 1999. He is working as Professor of Electrical Engineering in the National Institute of Technology, Warangal, India. His research interests include application of power electronics to DSP controlled industrial drives and renewable energy.
References
Moreland W. C. 1973 “The induction range: Its performance and its development problems,” IEEE Trans. Industry Applications IA-9 (1) 81 - 85    DOI : 10.1109/TIA.1973.349892
Miyamae Masaki , Ito Takahiro , Matsuse Kouki , Tsukahara Masayoshi 2012 “Performance of a High Frequency Quasi-Resonant Inverter with Variable-Frequency Output for Induction Heating” IEEE 7th International Power Electronics and Motion Control Conference Harbin, China
Kamli Mokhtar , Yamamoto Shigehiro , Abe Minoru 1996 “A 50-150 kHz Half-Bridge Inverter for Induction Heating Applications,” IEEE Trans. Industrial Electronics 43 (1) 163 - 172    DOI : 10.1109/41.481422
Ahmed S.M.W. , Eissa M.M. , Edress M. , Abdel-Hameed T.S. “Experimental investigation of full-bridge Series Resonant Inverters for Induction-Heating Cooking Appliances” 4th IEEE Conference on Industrial Electronics and Applications, ICIEA 2009 3327 - 3332
Okuno Atsushi , Kawano Hitoshi , Sun Junming , Kurokawa Manabu , Kojina Akira , Nakaoka Mutsuo 1998 “Feasible Development of Soft-Switched SIT Inverter with Load-Adaptive Frequency Tracking Control Scheme for Induction Heating,” IEEE Trans. Industry Applications 34 (4) 713 - 718    DOI : 10.1109/28.703962
Kwon Young-Sup , Yoo Sang-Bong , Hyun Dong-Seok 1999 “Half-Bridge Series Resonant Inverter for Induction Heating Applications with Load-Adaptive PFM Control Strategy” 14th Applied Power Electronics Conference and Exposition, APEC’ 99 1 575 - 581
Grajales L. , Sabate J. A. , Wang K. R. , Tabisz W. A. , Lee F.C. 1993 “Design of a 10 kW, 500 kHz Phase-Shift Controlled Series-Resonant Inverter for Induction Heating” Industry Applications Society Annual Meeting 2 843 - 849
Nagai Satoshi , Nagura Hirokazu , Nakaoka Mutsuo , Okuno Atsushi 1993 “High-Frequency Inverter with Phase-Shifted PWM and Load-Adaptive PFM Control Strategy for Industrial Induction-Heating” Industry Applications Society Annual Meeting 3 2165 - 2172
Shen Jinfei , Ma Hongbin , Yan Wenxu , Hui Jing , Wu Lei “PDM and PSM Hybrid Power Control of a Series-Resonant Inverter for Induction Heating Applications” IEEE Conference on Industrial Electronics and Applications, ICIEA 2006
Burdio J. M. , Barragan L. A. , Monterde F. , Navarro D. , Acero J. 2004 “Asymmetrical voltage cancellation control for full-bridge series resonant inverters,” IEEE Trans. Power Electronics 19 (2) 461 - 469    DOI : 10.1109/TPEL.2003.823250
Sarnago Hector , Lucia Oscar , Mediano Arturo , Burdio J.M. 2013 “Class D / DE Dual-Mode-Operation Resonant Converter for Improved-Efficiency Domestic Induction Heating System,” IEEE Transactions on Power Electronics 28 (3) 1274 - 1285    DOI : 10.1109/TPEL.2012.2206405
Forest F. , Laboure E. , Costa F. , Gaspard J.Y. 2000 “Principle of a multi-load / single converter system for low power induction heating,” IEEE Trans. Power Electronics 15 (2) 223 - 230    DOI : 10.1109/63.838094
Burdio Jose M. , Monterde Fernando , R. Garcia Jose , Barragan Luis A. , Martinez Abelardo 2005 “A Two-Output Series-Resonant Inverter for Induction-Heating Cooking Appliances,” IEEE Trans. Power Electronics 20 (4) 815 - 822
Zenitani S. , Okamoto M. , Hiraki E. , Tanaka T. 2010 “A Charge Boost Type Multi Output Full-Bridge High Frequency Soft Switching Inverter for IH Cooking Appliance,” 14th International Power Electronics and Motion Control Conference (EPE-PEMC) T2-127 - T2-133
Lucia Oscar , Burdio J.M. , Millan I. , Acero J. , Puyal D. 2009 “Load-Adaptive Control Algorithm of Half-Bridge Series Resonant Inverter for Domestic Induction Heating,” IEEE Transactions on Industrial Electronics 56 (8) 3106 - 3116
Lucia Oscar , Burdio Jose M. , Barragan Luis A. , Carretero Claudio , Acero Jesus 2011 “Series Resonant Multi-inverter with Discontinuous-Mode Control for Improved Light-Load Operation,” IEEE Transactions on Industrial Electronics 58 (11) 5163 - 5171    DOI : 10.1109/TIE.2011.2126541
Lucia Oscar , Urriza I. , Barragan Luis A. , Navarro D. , Jimenez Oscar , Burdio J.M. 2011 “Real Time FPGA-Based Hardware-in-the-Loop Simulation Test Bench Applied to Multiple-Output Power Converters,” IEEE Transactions on Industry Applications 47 (2) 853 - 860    DOI : 10.1109/TIA.2010.2102997
Lucia Oscar , Carretero Claudio , Burdio J.M. , Acero Jesus , Almazan Fernando 2012 “Multiple-Output Resonant Matrix Converter for Multiple Induction Heaters,” IEEE Transactions on Industry Applications 48 (4) 1387 - 1396    DOI : 10.1109/TIA.2012.2199456