D. Navarro - Academia.edu (original) (raw)

Papers by D. Navarro

Research paper thumbnail of FPGA-based harmonic computation through 1-bit data stream signals from delta-sigma modulators applied to induction heating appliances

2011 Twenty-Sixth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2011

This paper presents a field programmable gate array (FPGA) implementation of a digital circuit th... more This paper presents a field programmable gate array (FPGA) implementation of a digital circuit that measures in real-time first harmonics of voltage and current medium-frequency (25 kHz - 70 kHz) induction-heating cooking appliances. The inverter output voltage and load current are sensed using first-order delta-sigma () analog to digital converters. The coefficients of the Discrete-Time Fourier Series (DTFS) of voltage

Research paper thumbnail of VLSI implementation of discrete wavelet transform

IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 1996

Research paper thumbnail of Power Measurement for Resonant Power Converters Applied to Induction Heating Applications

IEEE Transactions on Power Electronics, 2014

ABSTRACT Nowadays, induction heating (IH) technology is dominating the domestic cooking market du... more ABSTRACT Nowadays, induction heating (IH) technology is dominating the domestic cooking market due to its advantages such as safety, cleanness, and high efficiency. Such high efficiency and high power density implementations are achieved by means of resonant power converters and, consequently, these need to be accurately controlled. This paper proposes a field-programmable gate array-based online power measurement system which allows the control system to perform the proper power control. The proposed power measurement system measures the output power from the digitized output voltage and current through two low-cost 1-bit second-order ΣΔ analog-to-digital converters. The bitstreams have been analyzed and, taking into account the results, several measurement approaches have been proposed and analyzed. Then, a noise sensitivity analysis has been performed in order to verify the proposed measurements methods. The analytical and simulation results have been tested through a resonant power converter applied to domestic IH whose switching frequency varies from 30 to 80 kHz. A statistical analysis of the implemented measurement approaches has been carried out in order to evaluate the system accuracy. Finally, the selected measurement method has been verified for several vessels. As a conclusion, an accurate and cost-effective output power measurement system is obtained, which can be applied to any resonant converter in the frequency operation range.

Research paper thumbnail of Reduced-order model of a half-bridge series resonant inverter for power control in domestic induction heating applications

2015 IEEE International Conference on Industrial Technology (ICIT), 2015

Research paper thumbnail of Decoupling output power control of two series resonant inverters sharing resonant capacitor for domestic induction heating

2014 IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL), 2014

Domestic induction heating applications require an accurate control of the power delivered to the... more Domestic induction heating applications require an accurate control of the power delivered to the vessel to be heated, ensuring power topology operation under safety conditions. Particularly, this paper is focused on applying a power control of two induction heating loads in a dual-half bridge sharing a common resonant capacitor. This topology leads to a control strategy harder than the classical arrangement which features a dedicated resonant capacitor. A Phase Shift Square Wave Modulation (PSSWM) is performed to control the output powers of the vessels to be heated. Thus, the considered plant is a two-input two-output (TITO) system. The two control inputs are (fsw, θ) and the two outputs are (P1, P2). Since the transfer function matrix is not diagonal, the Relative Gain Array (RGA) methodology is used to analyze if a multi-loop control is feasible. Due to the fact that the system is strongly coupled a centralized control must be applied. Therefore, the aim of the paper is to apply a decoupling control to handle the interactions. Simulation and experimental results in an induction heating prototype are performed in order to validate the proposed control technique.

Research paper thumbnail of Design of an FPGA-based full-state feedback controller using high level synthesis tools

2014 IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL), 2014

ABSTRACT Digital control has significantly advanced in the last decade enabling the implementatio... more ABSTRACT Digital control has significantly advanced in the last decade enabling the implementation of higher performance controllers using digital devices such as microcontrollers, DSPs or FPGAs. The design and implementation of controllers using FPGAs is often a challenging and time-consuming task. In order to improve this process, high level synthesis tools allow the use of high-level programming languages, easing the design and simulation process and enabling a straight-forward design space exploration. This paper details the overall design process using high level synthesis tools and presents as a representative example a full-state feedback controller for a buck converter using single-precision floating point representation. The main implementation and experimental results are summarized, highlighting the main benefits and drawbacks of this approach.

Research paper thumbnail of Implementation of an FPGA-Based On-Line Hardware-in-the-Loop Emulator Using High-Level Synthesis Tools for Resonant Power Converters Applied to Induction Heating Appliances

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, 2014

ABSTRACT This paper proposes a field-programmable-gate-array-based emulator of the series-resonan... more ABSTRACT This paper proposes a field-programmable-gate-array-based emulator of the series-resonant half-bridge inverter for measuring the inverter efficiency and detecting hard-switching conditions. The proposed emulator is able to compute the converter operating conditions and efficiency each mains half-cycle, providing useful information for the control unit. In addition, it is designed taking advantage of recent advances in high-level synthesis tools, which provides an optimized and straightforward implementation. The proposed emulator has been applied to an induction heating (IH) appliance as an example of efficient and environmentally friendly appliances with a major economic and social impact. The obtained results are compared with classical offline simulation and experimental measurements, proving that the proposed emulator achieves the required accuracy for the IH application. As a consequence, the proposed system can be used for improving the system safety and optimizing the converter efficiency and reliability.

Research paper thumbnail of PSO-based power control of two series resonant inverters sharing resonant capacitor for domestic induction heating

2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2013

ABSTRACT Current technology for domestic induction heating requires to deliver a wide range of po... more ABSTRACT Current technology for domestic induction heating requires to deliver a wide range of power (50 W–3.5 kW) to the vessel to be heated. In addition to this, the considered power control strategy must ensure high reachability and compliance with some constraints. This work is focused on applying the Phase Shift Control (PSC) modulation to control the power delivered to two induction loads. The considered topology is based on two half-bridge resonant inverters that control two domestic induction heating loads sharing a single resonant capacitor. The two outputs to be controlled are coupled, leading to a harder control problem. Therefore, a Particle Swarm Optimization (PSO) algorithm based on the gradient information is proposed to perform the power control by considering the PSC modulation. Finally, simulations are discussed and verified with some experimental results obtained in a prototype induction heating system.

Research paper thumbnail of System-on-programmable-chip-based versatile modulation architecture applied to domestic induction heating

2009 35th Annual Conference of IEEE Industrial Electronics, 2009

The development of ad-hoc control architectures is a time-consuming task which is often required ... more The development of ad-hoc control architectures is a time-consuming task which is often required to design and evaluate power converters. In this paper, an FPGA-based versatile control architecture test-bench which enables to evaluate and implement different control strategies applied to different power converter topologies is proposed. It is based on a hardware/software codesign by means of MicroBlaze softcore processor and

Research paper thumbnail of FPGA-based real-time harmonic impedance measurement of series resonant loads by using lock-in algorithm

IECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society, 2011

This paper presents a field programmable gate array (FPGA) implementation of a digital circuit th... more This paper presents a field programmable gate array (FPGA) implementation of a digital circuit that measures in real-time the first harmonic load impedance of medium-frequency (25 kHz – 75 kHz) induction-heating cooking appliances. The load impedance of these systems, which consist of a planar inductor coupled to a pan, depends on the pan material, temperature, and frequency. For this reason,

Research paper thumbnail of Frequency response measurement of DC-DC converters using a lock-in algorithm

2012 Twenty-Seventh Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2012

This paper presents a method to measure the control-to-output transfer function of dc-dc converte... more This paper presents a method to measure the control-to-output transfer function of dc-dc converters in open-loop. A sinusoidal perturbation is injected to the nominal value of the duty cycle, and a dual-phase lock-in algorithm is off-line applied to process the digitized input and response signals in order to compute the gain and phase of the transfer function. Lock-in algorithm is

Research paper thumbnail of Teaching digital electronics courses using high-level synthesis tools

2013 7th IEEE International Conference on e-Learning in Industrial Electronics (ICELIE), 2013

ABSTRACT Modern digital electronics courses usually include hardware description languages as a u... more ABSTRACT Modern digital electronics courses usually include hardware description languages as a useful tool to implement relatively complex digital designs using programmable logic devices. These languages are close to the final hardware architecture, but usually lead to long and complex design procedures. To overcome this limitation, high level synthesis tools provide an intuitive and straight-forward design flow using well-known programming languages such as C. This paper deals with the inclusion in a digital electronics course high-level synthesis tools to provide the student with a wider vision and additional design tools. An application example focused on digital control of power converters is provided, and the main benefits and drawbacks arisen are highlighted.

Research paper thumbnail of Static versus Dynamic Heterogeneities in the D=3 Edwards-Anderson-Ising Spin Glass

Physical Review Letters, 2010

Research paper thumbnail of Word length considerations on the hardware implementation of two‐dimensional Mallat’s wavelet transform

Optical Engineering, 1996

Two-dimensional discrete wavelet transforms (DWTs) have become a very powerful tool in computer v... more Two-dimensional discrete wavelet transforms (DWTs) have become a very powerful tool in computer vision. When implementing DWT in hardware, finite precision arithmetic introduces quantization errors. The hardware designer must look for the optimum register length which, while ...

Research paper thumbnail of Domestic Induction Appliances

IEEE Industry Applications Magazine, 2010

Research paper thumbnail of Taking into account Switching Events in Fixed Time-Step VHDL Simulation of Power Electronic Circuits

Research paper thumbnail of Nature of the spin-glass phase at experimental length scales

Journal of Statistical Mechanics: Theory and Experiment, 2010

Research paper thumbnail of Simulating spin systems on IANUS, an FPGA-based computer

Research paper thumbnail of Load identification of domestic induction heating based on Particle Swarm Optimization

2014 IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL), 2014

ABSTRACT Resonant power converters are widely used in domestic induction heating (IH) cooktops du... more ABSTRACT Resonant power converters are widely used in domestic induction heating (IH) cooktops due to their advantages in terms of size, efficiency, and power density. The wide range of different induction loads (with different electrical equivalent) and the wide range of required output powers, lead to the load identification as a mandatory and specially challenging aspect. This identification is needed to improve static operation, by identifying IH load that may lead to too high currents through the inverter, and dynamic operation, by correcting the gain of the digital controller according to the identified IH load. This work focuses on applying and evaluating the Particle Swarm Optimization (PSO) algorithm to identify the system load in domestic induction heating. Therefore, the obtained load parameters lead to a more efficient control strategy of the delivered power according to the user requirements. Simulation and experimental results in an induction heating prototype are performed in order to validate the proposed identification algorithm.

Research paper thumbnail of ASIC design for computing the Mallat's wavelet transform

Proceedings of Eighth International Application Specific Integrated Circuits Conference, 1995

Abstract - Wavelet Transforms have become a very powerful tool in Computer Vision. They are compu... more Abstract - Wavelet Transforms have become a very powerful tool in Computer Vision. They are computationally very intensive and real-time processing cannot be achieved with software implementations on a conventional Von-Neumann programmable computer. We have followed a top- ...

Research paper thumbnail of FPGA-based harmonic computation through 1-bit data stream signals from delta-sigma modulators applied to induction heating appliances

2011 Twenty-Sixth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2011

This paper presents a field programmable gate array (FPGA) implementation of a digital circuit th... more This paper presents a field programmable gate array (FPGA) implementation of a digital circuit that measures in real-time first harmonics of voltage and current medium-frequency (25 kHz - 70 kHz) induction-heating cooking appliances. The inverter output voltage and load current are sensed using first-order delta-sigma () analog to digital converters. The coefficients of the Discrete-Time Fourier Series (DTFS) of voltage

Research paper thumbnail of VLSI implementation of discrete wavelet transform

IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 1996

Research paper thumbnail of Power Measurement for Resonant Power Converters Applied to Induction Heating Applications

IEEE Transactions on Power Electronics, 2014

ABSTRACT Nowadays, induction heating (IH) technology is dominating the domestic cooking market du... more ABSTRACT Nowadays, induction heating (IH) technology is dominating the domestic cooking market due to its advantages such as safety, cleanness, and high efficiency. Such high efficiency and high power density implementations are achieved by means of resonant power converters and, consequently, these need to be accurately controlled. This paper proposes a field-programmable gate array-based online power measurement system which allows the control system to perform the proper power control. The proposed power measurement system measures the output power from the digitized output voltage and current through two low-cost 1-bit second-order ΣΔ analog-to-digital converters. The bitstreams have been analyzed and, taking into account the results, several measurement approaches have been proposed and analyzed. Then, a noise sensitivity analysis has been performed in order to verify the proposed measurements methods. The analytical and simulation results have been tested through a resonant power converter applied to domestic IH whose switching frequency varies from 30 to 80 kHz. A statistical analysis of the implemented measurement approaches has been carried out in order to evaluate the system accuracy. Finally, the selected measurement method has been verified for several vessels. As a conclusion, an accurate and cost-effective output power measurement system is obtained, which can be applied to any resonant converter in the frequency operation range.

Research paper thumbnail of Reduced-order model of a half-bridge series resonant inverter for power control in domestic induction heating applications

2015 IEEE International Conference on Industrial Technology (ICIT), 2015

Research paper thumbnail of Decoupling output power control of two series resonant inverters sharing resonant capacitor for domestic induction heating

2014 IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL), 2014

Domestic induction heating applications require an accurate control of the power delivered to the... more Domestic induction heating applications require an accurate control of the power delivered to the vessel to be heated, ensuring power topology operation under safety conditions. Particularly, this paper is focused on applying a power control of two induction heating loads in a dual-half bridge sharing a common resonant capacitor. This topology leads to a control strategy harder than the classical arrangement which features a dedicated resonant capacitor. A Phase Shift Square Wave Modulation (PSSWM) is performed to control the output powers of the vessels to be heated. Thus, the considered plant is a two-input two-output (TITO) system. The two control inputs are (fsw, θ) and the two outputs are (P1, P2). Since the transfer function matrix is not diagonal, the Relative Gain Array (RGA) methodology is used to analyze if a multi-loop control is feasible. Due to the fact that the system is strongly coupled a centralized control must be applied. Therefore, the aim of the paper is to apply a decoupling control to handle the interactions. Simulation and experimental results in an induction heating prototype are performed in order to validate the proposed control technique.

Research paper thumbnail of Design of an FPGA-based full-state feedback controller using high level synthesis tools

2014 IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL), 2014

ABSTRACT Digital control has significantly advanced in the last decade enabling the implementatio... more ABSTRACT Digital control has significantly advanced in the last decade enabling the implementation of higher performance controllers using digital devices such as microcontrollers, DSPs or FPGAs. The design and implementation of controllers using FPGAs is often a challenging and time-consuming task. In order to improve this process, high level synthesis tools allow the use of high-level programming languages, easing the design and simulation process and enabling a straight-forward design space exploration. This paper details the overall design process using high level synthesis tools and presents as a representative example a full-state feedback controller for a buck converter using single-precision floating point representation. The main implementation and experimental results are summarized, highlighting the main benefits and drawbacks of this approach.

Research paper thumbnail of Implementation of an FPGA-Based On-Line Hardware-in-the-Loop Emulator Using High-Level Synthesis Tools for Resonant Power Converters Applied to Induction Heating Appliances

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, 2014

ABSTRACT This paper proposes a field-programmable-gate-array-based emulator of the series-resonan... more ABSTRACT This paper proposes a field-programmable-gate-array-based emulator of the series-resonant half-bridge inverter for measuring the inverter efficiency and detecting hard-switching conditions. The proposed emulator is able to compute the converter operating conditions and efficiency each mains half-cycle, providing useful information for the control unit. In addition, it is designed taking advantage of recent advances in high-level synthesis tools, which provides an optimized and straightforward implementation. The proposed emulator has been applied to an induction heating (IH) appliance as an example of efficient and environmentally friendly appliances with a major economic and social impact. The obtained results are compared with classical offline simulation and experimental measurements, proving that the proposed emulator achieves the required accuracy for the IH application. As a consequence, the proposed system can be used for improving the system safety and optimizing the converter efficiency and reliability.

Research paper thumbnail of PSO-based power control of two series resonant inverters sharing resonant capacitor for domestic induction heating

2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2013

ABSTRACT Current technology for domestic induction heating requires to deliver a wide range of po... more ABSTRACT Current technology for domestic induction heating requires to deliver a wide range of power (50 W–3.5 kW) to the vessel to be heated. In addition to this, the considered power control strategy must ensure high reachability and compliance with some constraints. This work is focused on applying the Phase Shift Control (PSC) modulation to control the power delivered to two induction loads. The considered topology is based on two half-bridge resonant inverters that control two domestic induction heating loads sharing a single resonant capacitor. The two outputs to be controlled are coupled, leading to a harder control problem. Therefore, a Particle Swarm Optimization (PSO) algorithm based on the gradient information is proposed to perform the power control by considering the PSC modulation. Finally, simulations are discussed and verified with some experimental results obtained in a prototype induction heating system.

Research paper thumbnail of System-on-programmable-chip-based versatile modulation architecture applied to domestic induction heating

2009 35th Annual Conference of IEEE Industrial Electronics, 2009

The development of ad-hoc control architectures is a time-consuming task which is often required ... more The development of ad-hoc control architectures is a time-consuming task which is often required to design and evaluate power converters. In this paper, an FPGA-based versatile control architecture test-bench which enables to evaluate and implement different control strategies applied to different power converter topologies is proposed. It is based on a hardware/software codesign by means of MicroBlaze softcore processor and

Research paper thumbnail of FPGA-based real-time harmonic impedance measurement of series resonant loads by using lock-in algorithm

IECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society, 2011

This paper presents a field programmable gate array (FPGA) implementation of a digital circuit th... more This paper presents a field programmable gate array (FPGA) implementation of a digital circuit that measures in real-time the first harmonic load impedance of medium-frequency (25 kHz – 75 kHz) induction-heating cooking appliances. The load impedance of these systems, which consist of a planar inductor coupled to a pan, depends on the pan material, temperature, and frequency. For this reason,

Research paper thumbnail of Frequency response measurement of DC-DC converters using a lock-in algorithm

2012 Twenty-Seventh Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2012

This paper presents a method to measure the control-to-output transfer function of dc-dc converte... more This paper presents a method to measure the control-to-output transfer function of dc-dc converters in open-loop. A sinusoidal perturbation is injected to the nominal value of the duty cycle, and a dual-phase lock-in algorithm is off-line applied to process the digitized input and response signals in order to compute the gain and phase of the transfer function. Lock-in algorithm is

Research paper thumbnail of Teaching digital electronics courses using high-level synthesis tools

2013 7th IEEE International Conference on e-Learning in Industrial Electronics (ICELIE), 2013

ABSTRACT Modern digital electronics courses usually include hardware description languages as a u... more ABSTRACT Modern digital electronics courses usually include hardware description languages as a useful tool to implement relatively complex digital designs using programmable logic devices. These languages are close to the final hardware architecture, but usually lead to long and complex design procedures. To overcome this limitation, high level synthesis tools provide an intuitive and straight-forward design flow using well-known programming languages such as C. This paper deals with the inclusion in a digital electronics course high-level synthesis tools to provide the student with a wider vision and additional design tools. An application example focused on digital control of power converters is provided, and the main benefits and drawbacks arisen are highlighted.

Research paper thumbnail of Static versus Dynamic Heterogeneities in the D=3 Edwards-Anderson-Ising Spin Glass

Physical Review Letters, 2010

Research paper thumbnail of Word length considerations on the hardware implementation of two‐dimensional Mallat’s wavelet transform

Optical Engineering, 1996

Two-dimensional discrete wavelet transforms (DWTs) have become a very powerful tool in computer v... more Two-dimensional discrete wavelet transforms (DWTs) have become a very powerful tool in computer vision. When implementing DWT in hardware, finite precision arithmetic introduces quantization errors. The hardware designer must look for the optimum register length which, while ...

Research paper thumbnail of Domestic Induction Appliances

IEEE Industry Applications Magazine, 2010

Research paper thumbnail of Taking into account Switching Events in Fixed Time-Step VHDL Simulation of Power Electronic Circuits

Research paper thumbnail of Nature of the spin-glass phase at experimental length scales

Journal of Statistical Mechanics: Theory and Experiment, 2010

Research paper thumbnail of Simulating spin systems on IANUS, an FPGA-based computer

Research paper thumbnail of Load identification of domestic induction heating based on Particle Swarm Optimization

2014 IEEE 15th Workshop on Control and Modeling for Power Electronics (COMPEL), 2014

ABSTRACT Resonant power converters are widely used in domestic induction heating (IH) cooktops du... more ABSTRACT Resonant power converters are widely used in domestic induction heating (IH) cooktops due to their advantages in terms of size, efficiency, and power density. The wide range of different induction loads (with different electrical equivalent) and the wide range of required output powers, lead to the load identification as a mandatory and specially challenging aspect. This identification is needed to improve static operation, by identifying IH load that may lead to too high currents through the inverter, and dynamic operation, by correcting the gain of the digital controller according to the identified IH load. This work focuses on applying and evaluating the Particle Swarm Optimization (PSO) algorithm to identify the system load in domestic induction heating. Therefore, the obtained load parameters lead to a more efficient control strategy of the delivered power according to the user requirements. Simulation and experimental results in an induction heating prototype are performed in order to validate the proposed identification algorithm.

Research paper thumbnail of ASIC design for computing the Mallat's wavelet transform

Proceedings of Eighth International Application Specific Integrated Circuits Conference, 1995

Abstract - Wavelet Transforms have become a very powerful tool in Computer Vision. They are compu... more Abstract - Wavelet Transforms have become a very powerful tool in Computer Vision. They are computationally very intensive and real-time processing cannot be achieved with software implementations on a conventional Von-Neumann programmable computer. We have followed a top- ...