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Simone Buso

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I am an electronic engineer and a power electronics expert. I received the M.Sc. degree in electronic engineering and the Ph.D. degree in industrial electronics from the University of Padova, Italy, in 1992 and 1997, respectively. I am currently an Associate Professor of electronics with the Department of Information Engineering (DEI) at the University of Padova (ITALY).My research interests are in the industrial and power electronics fields, specifically related to switching converter topologies, digital control of power converters, renewable energy sources and smart micro-grids.

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Papers by Simone Buso

Design of a robust voltage controller for a buck-boost converter using μ-synthesis

IEEE Transactions on Control Systems Technology, 1999

This paper proposes the structured singular value () approach to the problem of designing an outp... more This paper proposes the structured singular value () approach to the problem of designing an output voltage regulator for a Buck-Boost converter with current-mode control. This approach allows a quantitative description of the effects of reactive components' tolerances and operating point variations, which strongly affect the converter dynamics. At first, a suitable linear converter model is derived, whose parameter variations are described in terms of perturbations of the linear fractional transformation (LFT) class. Then,-analysis is used to evaluate the robustness of a conventional PI voltage regulator with respect to the modeled perturbations. Finally, the approximate-synthesis procedure known as D-K iteration is used to design a robustly performing regulator. Simulation results are presented, describing the small and large signal behavior of a reduced order approximation of the-synthesized controller. Index Terms-DC-DC power conversion, H-infinity control, H-infinity optimization, robustness, uncertain systems.

Nonlinearities of Multi-Sampled Phase-Shifted PWM in Unbalanced Multi-Cell Converters

IEEE Journal of Emerging and Selected Topics in Power Electronics, Dec 31, 2022

This article reveals, analyzes and proposes the method to mitigate nonlinear effects of multi-sam... more This article reveals, analyzes and proposes the method to mitigate nonlinear effects of multi-sampled multiupdate (MSMU) digital phase-shifted pulsewidth modulators (PS-DPWM) that appear in unbalanced multi-cell voltage-source converters (MC-VSCs). For balanced MC-VSCs, the harmonic cancellation of PS-DPWM allows for an increase in the sampling frequency, ensuring that the average current is acquired at the peaks, valleys, and intersections of all triangular carriers. For unbalanced operation, which is typically encountered in practice, e.g., due to cell voltage mismatch in multilevel MC-VSCs and inductance mismatch in interleaved MC-VSCs, harmonic cancellation of PS-DPWM is compromised and, thus, the increased sampling frequency brings switching ripple in the feedback signal. Since in MSMU control the modulating signal is also updated at peaks, valleys, and intersections of all carriers, this may cause vertical intersections between the modulating signal and the carriers, resulting in specific nonlinear effects. The nonlinearities are shown to introduce limit-cycle oscillations and output waveform distortion. A method to prevent such detrimental impact of MSMU-PS-PWM is also proposed. A simple analytical procedure is proposed to quantify the analyzed non-linear effects, revealing that they are more emphasized for higher levels of imbalance and control bandwidth. Moreover, the modulator nonlinearity is shown to decrease as the number of cells increases. The analyses are verified in simulations and experiments, using laboratory prototypes of three-and four-level MC-VSCs.

An Isolated Soft-Switched High-Power-Factor Rectifier Based on the Asymmetrical Half-Bridge Flyback Converter

IEEE Transactions on Industrial Electronics, Jul 1, 2022

This article presents the analysis and design of a high-power-factor rectifier that integrates a ... more This article presents the analysis and design of a high-power-factor rectifier that integrates a discontinuous conduction mode operated Boost input cell with an asymmetrical half-bridge flyback converter (AHBFC). The particular connection of the dc-dc stage with the boost cell makes the dc link voltage decrease at light load, thus naturally limiting the switches' voltage stress. A suitable design procedure is described that accounts for the resonant nature of the AHBFC, and allows to calculate all converter parameters to meet the design specifications and to achieve zero-voltage turn-ON for the switches in any operating condition, considering both input voltage and load variations. The theoretical analysis is validated by experimental results taken on a 160 W rated prototype, working at the nominal switching frequency f s = 400 kHz, with a line voltage rms value ranging from 85 to 135 V.

• Uso di mC e DSP in applicazioni di Signal Processing e controllo • Filtri FIR e IIR • Regolatori PI e PID • Regolatori predittivi (cenni)

Uno degli usi più frequenti di mC e DSP è nello svolgimento di funzioni di elaborazione numerica ... more Uno degli usi più frequenti di mC e DSP è nello svolgimento di funzioni di elaborazione numerica del segnale e/o di controllo real-time di processi o sistemi. La distinzione fondamentale tra queste due attività è data dalla retroazione, assente nella prima, indispensabile nella seconda. Le problematiche di questo tipo di applicazioni sono legate al funzionamento a tempo discreto dei processori, alla precisione finita della loro aritmetica e alla quantizzazione di dati e coefficienti.

Power Factor Preregulators Based on Combined

The limitation imposed on the achievable power level by the IEC 1000-3-2 standard in buck-derived... more The limitation imposed on the achievable power level by the IEC 1000-3-2 standard in buck-derived power factor preregulators, is overcome by using a combined buck-flyback power stage. Two different step-down converters are proposed in this paper, which incorporate an auxiliary flyback stage. The auxiliary stage uses the same switch of the main converter, plus an additional power switch commutated at the line frequency. As compared to a simple buck rectifier, with this solution the harmonic content of the absorbed line current, at a given power level, can be reduced, thanks to the resulting increased conduction angle of the input rectifier bridge. Experimental results based on a 1 kW prototype are reported to validate the theoretical analysis of the proposed topologies.

Accurate High-Frequency Modeling of the Input Admittance of PWM Grid-Connected VSCs

IEEE Transactions on Power Electronics

This article addresses high-frequency admittance modeling of current-controlled voltage source co... more This article addresses high-frequency admittance modeling of current-controlled voltage source converters (VSCs). Recent studies have shown that harmonic instability may also occur at frequencies above the Nyquist frequency. To form an accurate multiple-frequency model in this frequency range, sidebands that originate from modulation and sampling must be examined. In this article, an accurate small-signal model is developed taking into account an adequate digital pulsewidth modulator (DPWM) representation, which allows to predict dependence of the frequency response on the steady-state dc (SS-dc) operating point. It is shown that when center-pulse sampling is implemented, pulsewidth modulation sidebands do not create additional loops leaving only sampling sidebands to be considered. Using the same approach as for SS-dc operation, a model that accurately represents admittance measurements during sinusoidal ac (S-ac) operation is developed. Its basis is a novel DPWM model suitable for S-ac regime, which allows to predict dependence of the VSC's input admittance on the grid voltage magnitude. Experimental and simulated admittance measurements, performed on a single-phase two-level VSC during various SS-dc and S-ac regimes, match with the proposed models up to twice the sampling frequency.

An 8W-2MHz buck converter with adaptive dead time tolerant to radiation and high magnetic field

2010 Proceedings of ESSCIRC, 2010

A high efficiency 8W-2MHz ASIC buck converter tolerant to radiation and high magnetic field is pr... more A high efficiency 8W-2MHz ASIC buck converter tolerant to radiation and high magnetic field is presented. A new adaptive control circuit for the dead time management is integrated to increase the efficiency during quasi-square wave (QSW) operation. The ASIC is designed in the IHP SGB25GOD 0.25μm technology and developed for the Large Handron Collider (LHC) experiments upgrade, where the main constrains are the presence of a severe radiation environment (up to hundreds of Mrad), a high magnetic field (up to 4 Tesla) and mass limitation because extra material is detrimental to the physics performance of the detector.

A new soft-switching forward DC-DC converter operating in discontinuous conduction mode

2002 IEEE 33rd Annual IEEE Power Electronics Specialists Conference. Proceedings (Cat. No.02CH37289)

The paper presents a simple soft-switching forward DC-DC converter suitable for low power applica... more The paper presents a simple soft-switching forward DC-DC converter suitable for low power applications. A lossless passive turn-off snubber is employed to provide zero voltage turn off of the switch as well as transformer reset. Moreover, the choice to operate the converter in discontinuous conduction mode (DCM), while providing zero current turn on of the switch, also allows to simplify the topology by eliminating the inductive output filter. A detailed converter analysis, aimed to highlight advantages and drawbacks of the presented topology, is reported, together with a suitable design procedure. Experimental results are also included to verify the theoretical expectations.

Custom DC-DC converters for distributing power in SLHC trackers

A power distribution scheme based on the use of on-board DC-DC converters is proposed to efficien... more A power distribution scheme based on the use of on-board DC-DC converters is proposed to efficiently distribute power to the on-detector electronics of SLHC trackers. A comparative analysis of different promising converter topologies is presented, leading to the choice of a magneticbased buck converter as a first conversion stage followed by an on-chip switched capacitors converter. An overall efficiency above 80% is estimated for the practical implementation proposed. I. SLHC POWER DISTRIBUTION NEEDS In the design of upgraded trackers for SLHC, the required increase in the number of readout channels should not lead to a heavier tracker. Since cables and cooling are amongst the main contributors to the material budget, and they are both dependent on the amount of power burnt in the tracker, ondetector power management is necessary. It is important to both decreasing the power per function ratio of Front-End (FE) electronics, and to distributing the power efficiently. The first objec...

Retificadores de alta qualidade com comutação em alta ou em baixa frequência - um estudo comparativo

Eletrônica de Potência, 2001

Comparison between two single-switch isolated flyback and forward high-quality rectifiers for low power applications

APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335)

In this paper, two isolated single-switch high-quality rectifiers are compared: one is based on t... more In this paper, two isolated single-switch high-quality rectifiers are compared: one is based on the forward topology with secondary side resonant reset, the other is a flyback rectifier with a lossless passive snubber. These rectifiers were both designed for universal input voltage range (90 ÷ ÷ ÷ ÷ 260 V RMS) and 200 W nominal output power. The adopted control technique is a modified non-linear carrier control based on the integration of the switch current signal, which does not require any input voltage sensing, analog multiplier and current error amplifier. The comparison is based both on theoretical analysis and measurements on fully developed prototypes and takes into account the following aspects: basic design guidelines, voltage and current rating of active devices, power losses on the main devices, overall efficiency and conducted EMI generation. This work, highlighting advantages and drawbacks of both the selected topologies, will allow designers to make a proper choice for a given application in the low power range (below 300W).

Analysis of the active-clamped soft-switched forward converter without output filter

2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551)

This paper analyzes an active-clamped softswitched forward converter without output filter. Diffe... more This paper analyzes an active-clamped softswitched forward converter without output filter. Differently from the topology presented in 111, the transformer reset is obtained by using an active clamp subcircuit instead ofa lossless passive snubber. This solution avoids the use of a second inductor and auxiliary diodes and allows a better exploitation ofthe converter components, since now both the main and the auxiliary switch turn on at zero voltage and zero current, and they turn off at zero voltage by using a loss-less capacitor. The resulting topology is practically identical to that of an activeclamped flyback converter, except for the reversed transformer secondary side polarity. Thus, in addition to the converter analysis, the paper presents a comparison between the proposed converter and the active-clamped flyback converter, by testing two prototypes rated for 48W output power.

Digital Control in Power Electronics, 2nd Edition

Synthesis Lectures on Power Electronics, 2015

Synthesis Lectures on Power Electronics will publish 50-to 100-page publications on topics relate... more Synthesis Lectures on Power Electronics will publish 50-to 100-page publications on topics related to power electronics, ancillary components, packaging and integration, electric machines and their drive systems, as well as related subjects such as EMI and power quality. Each lecture develops a particular topic with the requisite introductory material and progresses to more advanced subject matter such that a comprehensive body of knowledge is encompassed. Simulation and modeling techniques and examples are included where applicable. e authors selected to write the lectures are leading experts on each subject who have extensive backgrounds in the theory, design, and implementation of power electronics, and electric machines and drives. e series is designed to meet the demands of modern engineers, technologists, and engineering managers who face the increased electrification and proliferation of power processing systems into all aspects of electrical engineering applications and must learn to design, incorporate, or maintain these systems.

A low-loss high-power-factor flyback rectifier suitable for smart power integration

2000 IEEE 31st Annual Power Electronics Specialists Conference. Conference Proceedings (Cat. No.00CH37018), 2000

A low-loss, high-power-factor flyback rectifier is presented, which is designed as a possible app... more A low-loss, high-power-factor flyback rectifier is presented, which is designed as a possible application for a new type of smart power integrated circuit. This is going to be manufactured by ST Microelectronics using the VIPower © M3 technology and will include on the same silicon chip both control circuitry and an emitter switching power device. In order to avoid dangerous interactions between power and control part of the integrated circuit, it is necessary to control the rate of change of the power device voltage at turn-off. Accordingly, a lossless passive snubber was added to the conventional converter topology. The snubber also limits the voltage spikes across the power device, due to the transformer leakage inductance, and reduces the electromagnetic noise generation. A modified non-linear carrier control is considered which, thanks to the integration of the switch current signal, ensures high power factor and inherent noise immunity together with a simple control implementation (no need of input voltage sensing, multiplier and current error amplifier). A 200 W converter prototype was tested in order to evaluate the achievable performance.

Susceptibility of integrated circuits to RFI: analysis of PWM current-mode controllers for SMPS

IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02

This paper deals with the analysis of the effects of radio frequency conducted interfering signal... more This paper deals with the analysis of the effects of radio frequency conducted interfering signals (RFI) on integrated circuits (IC's). After reviewing the basic results of the susceptibility analysis of operational amplifiers and smart power integrated circuits, the behavior of several pin-to-pin compatible control IC's for PWM current-mode switching power supplies (SMPS) has been tested in the presence of both continuous wave interfering signals (CW) as well as of pulsed noise signals (underground condition). The tested ICs were selected between some common models available on the market. The variations of the primary functional parameters (inner voltage reference, switching frequency, etc.) are evaluated in different test conditions. The paper gives a comparative view of the results, focusing on the key macroscopic effects.

Power factor preregulator based on modified tapped-inductor buck converter

1998 International Conference on Power Electronic Drives and Energy Systems for Industrial Growth, 1998. Proceedings.

Power factor preregulators based on buck-type converters with capacitive output filter do not all... more Power factor preregulators based on buck-type converters with capacitive output filter do not allow a unity power factor due to their inability to draw current from the ac line during those intervals when the input voltage is lower than the output one. This limitation can be overcome by using a modified tapped-inductor buck topology, which can be arranged to operate as a flyback converter when desired. This modification, which requires only an extra line-frequency commutated switch and a diode, allows to extend the input current conduction angle, thus making the converter compliant with harmonic standards like IEC 1000-3-2. A 1kW converter has been designed, built and tested to validate the theoretical forecasts.

Conducted EMI issues in a boost PFC design

INTELEC - Twentieth International Telecommunications Energy Conference (Cat. No.98CH36263)

The paper presents the results of an experimental activity concerned with the development of a 60... more The paper presents the results of an experimental activity concerned with the development of a 600W Boost Power Factor Corrector (PFC) complying with the EMC standards for conducted EMI in the 150kHz-30MHz range. In order to accomplish this task, different circuit design and layout solutions are taken into account and their effect on the conducted EMI behavior of the converter is experimentally evaluated. Common-mode and differential-mode switching noise, together with input filters' design and topology and with the PCB layout (in terms of track length and spacing, ground and shielding planes etc.) are the key aspects which have been analyzed. In particular, the paper reports the conducted EMI measurements for different filter capacitor placements and values, for different power switch drive circuits together with several other provisions which have turned out to be decisive in the reduction of the generated EMI.

Single-phase AC/DC integrated PWM converter

INTELEC. Twenty-Second International Telecommunications Energy Conference (Cat. No.00CH37131), 2000

The paper proposes a new topology of a boost type ac/dc PWM converter featuring high power factor... more The paper proposes a new topology of a boost type ac/dc PWM converter featuring high power factor, full control of the output dc voltage and high-frequency line filter inductor and insulation transformer. Its main advantage is the complete integration of a rectifier and an inverter stage, so that a compact converter with only four IGBT's and six diodes is obtained. The integration poses some constraints on the line current control capability of the converter, which is limited. Nevertheless, the compliance with EMC standards (IEC 61000-3-2) is possible for a wide load range. The paper presents a detailed analysis of the topology, highlighting the design constraints and proposes a possible design procedure, which is then verified by means of numerical simulations.

Power factor preregulators based on combined buck-flyback topologies

IEEE Transactions on Power Electronics, 2000

The limitation imposed on the achievable power level by the IEC 1000-3-2 standard in buck-derived... more The limitation imposed on the achievable power level by the IEC 1000-3-2 standard in buck-derived power factor preregulators, is overcome by using a combined buck-flyback power stage. Two different step-down converters are proposed in this paper, which incorporate an auxiliary flyback stage. The auxiliary stage uses the same switch of the main converter, plus an additional power switch commutated at the line frequency. As compared to a simple buck rectifier, with this solution the harmonic content of the absorbed line current, at a given power level, can be reduced, thanks to the resulting increased conduction angle of the input rectifier bridge. Experimental results based on a 1 kW prototype are reported to validate the theoretical analysis of the proposed topologies.

Optimization of Shielded PCB Air-Core Toroids for High-Efficiency DC–DC Converters

IEEE Transactions on Power Electronics, 2011

The paper describes the design of optimized printed circuit board (PCB) air-core toroids for high... more The paper describes the design of optimized printed circuit board (PCB) air-core toroids for high-frequency dc-dc converters with strict requirements in terms of volume and noise. The effect of several design parameters on the overall inductor volume, on dc and ac winding resistance, and on the radiated noise will be investigated. PCB toroids are compared to standard air-core solenoids and other state-of-the-art air-core toroids both theoretically and experimentally: at first, using ANSOFT Maxwell and ANSOFT Q3D simulation tools, and subsequently, with laboratory measurements (irradiated noise, efficiency, and frequency response) on several prototypes. These very flexible and rather easy to manufacture inductors appear very attractive for compact highfrequency dc-dc converters where high efficiency, low volume, and low noise are of primary concern.

Design of a robust voltage controller for a buck-boost converter using μ-synthesis

IEEE Transactions on Control Systems Technology, 1999

This paper proposes the structured singular value () approach to the problem of designing an outp... more This paper proposes the structured singular value () approach to the problem of designing an output voltage regulator for a Buck-Boost converter with current-mode control. This approach allows a quantitative description of the effects of reactive components' tolerances and operating point variations, which strongly affect the converter dynamics. At first, a suitable linear converter model is derived, whose parameter variations are described in terms of perturbations of the linear fractional transformation (LFT) class. Then,-analysis is used to evaluate the robustness of a conventional PI voltage regulator with respect to the modeled perturbations. Finally, the approximate-synthesis procedure known as D-K iteration is used to design a robustly performing regulator. Simulation results are presented, describing the small and large signal behavior of a reduced order approximation of the-synthesized controller. Index Terms-DC-DC power conversion, H-infinity control, H-infinity optimization, robustness, uncertain systems.

Nonlinearities of Multi-Sampled Phase-Shifted PWM in Unbalanced Multi-Cell Converters

IEEE Journal of Emerging and Selected Topics in Power Electronics, Dec 31, 2022

This article reveals, analyzes and proposes the method to mitigate nonlinear effects of multi-sam... more This article reveals, analyzes and proposes the method to mitigate nonlinear effects of multi-sampled multiupdate (MSMU) digital phase-shifted pulsewidth modulators (PS-DPWM) that appear in unbalanced multi-cell voltage-source converters (MC-VSCs). For balanced MC-VSCs, the harmonic cancellation of PS-DPWM allows for an increase in the sampling frequency, ensuring that the average current is acquired at the peaks, valleys, and intersections of all triangular carriers. For unbalanced operation, which is typically encountered in practice, e.g., due to cell voltage mismatch in multilevel MC-VSCs and inductance mismatch in interleaved MC-VSCs, harmonic cancellation of PS-DPWM is compromised and, thus, the increased sampling frequency brings switching ripple in the feedback signal. Since in MSMU control the modulating signal is also updated at peaks, valleys, and intersections of all carriers, this may cause vertical intersections between the modulating signal and the carriers, resulting in specific nonlinear effects. The nonlinearities are shown to introduce limit-cycle oscillations and output waveform distortion. A method to prevent such detrimental impact of MSMU-PS-PWM is also proposed. A simple analytical procedure is proposed to quantify the analyzed non-linear effects, revealing that they are more emphasized for higher levels of imbalance and control bandwidth. Moreover, the modulator nonlinearity is shown to decrease as the number of cells increases. The analyses are verified in simulations and experiments, using laboratory prototypes of three-and four-level MC-VSCs.

An Isolated Soft-Switched High-Power-Factor Rectifier Based on the Asymmetrical Half-Bridge Flyback Converter

IEEE Transactions on Industrial Electronics, Jul 1, 2022

This article presents the analysis and design of a high-power-factor rectifier that integrates a ... more This article presents the analysis and design of a high-power-factor rectifier that integrates a discontinuous conduction mode operated Boost input cell with an asymmetrical half-bridge flyback converter (AHBFC). The particular connection of the dc-dc stage with the boost cell makes the dc link voltage decrease at light load, thus naturally limiting the switches' voltage stress. A suitable design procedure is described that accounts for the resonant nature of the AHBFC, and allows to calculate all converter parameters to meet the design specifications and to achieve zero-voltage turn-ON for the switches in any operating condition, considering both input voltage and load variations. The theoretical analysis is validated by experimental results taken on a 160 W rated prototype, working at the nominal switching frequency f s = 400 kHz, with a line voltage rms value ranging from 85 to 135 V.

• Uso di mC e DSP in applicazioni di Signal Processing e controllo • Filtri FIR e IIR • Regolatori PI e PID • Regolatori predittivi (cenni)

Uno degli usi più frequenti di mC e DSP è nello svolgimento di funzioni di elaborazione numerica ... more Uno degli usi più frequenti di mC e DSP è nello svolgimento di funzioni di elaborazione numerica del segnale e/o di controllo real-time di processi o sistemi. La distinzione fondamentale tra queste due attività è data dalla retroazione, assente nella prima, indispensabile nella seconda. Le problematiche di questo tipo di applicazioni sono legate al funzionamento a tempo discreto dei processori, alla precisione finita della loro aritmetica e alla quantizzazione di dati e coefficienti.

Power Factor Preregulators Based on Combined

The limitation imposed on the achievable power level by the IEC 1000-3-2 standard in buck-derived... more The limitation imposed on the achievable power level by the IEC 1000-3-2 standard in buck-derived power factor preregulators, is overcome by using a combined buck-flyback power stage. Two different step-down converters are proposed in this paper, which incorporate an auxiliary flyback stage. The auxiliary stage uses the same switch of the main converter, plus an additional power switch commutated at the line frequency. As compared to a simple buck rectifier, with this solution the harmonic content of the absorbed line current, at a given power level, can be reduced, thanks to the resulting increased conduction angle of the input rectifier bridge. Experimental results based on a 1 kW prototype are reported to validate the theoretical analysis of the proposed topologies.

Accurate High-Frequency Modeling of the Input Admittance of PWM Grid-Connected VSCs

IEEE Transactions on Power Electronics

This article addresses high-frequency admittance modeling of current-controlled voltage source co... more This article addresses high-frequency admittance modeling of current-controlled voltage source converters (VSCs). Recent studies have shown that harmonic instability may also occur at frequencies above the Nyquist frequency. To form an accurate multiple-frequency model in this frequency range, sidebands that originate from modulation and sampling must be examined. In this article, an accurate small-signal model is developed taking into account an adequate digital pulsewidth modulator (DPWM) representation, which allows to predict dependence of the frequency response on the steady-state dc (SS-dc) operating point. It is shown that when center-pulse sampling is implemented, pulsewidth modulation sidebands do not create additional loops leaving only sampling sidebands to be considered. Using the same approach as for SS-dc operation, a model that accurately represents admittance measurements during sinusoidal ac (S-ac) operation is developed. Its basis is a novel DPWM model suitable for S-ac regime, which allows to predict dependence of the VSC's input admittance on the grid voltage magnitude. Experimental and simulated admittance measurements, performed on a single-phase two-level VSC during various SS-dc and S-ac regimes, match with the proposed models up to twice the sampling frequency.

An 8W-2MHz buck converter with adaptive dead time tolerant to radiation and high magnetic field

2010 Proceedings of ESSCIRC, 2010

A high efficiency 8W-2MHz ASIC buck converter tolerant to radiation and high magnetic field is pr... more A high efficiency 8W-2MHz ASIC buck converter tolerant to radiation and high magnetic field is presented. A new adaptive control circuit for the dead time management is integrated to increase the efficiency during quasi-square wave (QSW) operation. The ASIC is designed in the IHP SGB25GOD 0.25μm technology and developed for the Large Handron Collider (LHC) experiments upgrade, where the main constrains are the presence of a severe radiation environment (up to hundreds of Mrad), a high magnetic field (up to 4 Tesla) and mass limitation because extra material is detrimental to the physics performance of the detector.

A new soft-switching forward DC-DC converter operating in discontinuous conduction mode

2002 IEEE 33rd Annual IEEE Power Electronics Specialists Conference. Proceedings (Cat. No.02CH37289)

The paper presents a simple soft-switching forward DC-DC converter suitable for low power applica... more The paper presents a simple soft-switching forward DC-DC converter suitable for low power applications. A lossless passive turn-off snubber is employed to provide zero voltage turn off of the switch as well as transformer reset. Moreover, the choice to operate the converter in discontinuous conduction mode (DCM), while providing zero current turn on of the switch, also allows to simplify the topology by eliminating the inductive output filter. A detailed converter analysis, aimed to highlight advantages and drawbacks of the presented topology, is reported, together with a suitable design procedure. Experimental results are also included to verify the theoretical expectations.

Custom DC-DC converters for distributing power in SLHC trackers

A power distribution scheme based on the use of on-board DC-DC converters is proposed to efficien... more A power distribution scheme based on the use of on-board DC-DC converters is proposed to efficiently distribute power to the on-detector electronics of SLHC trackers. A comparative analysis of different promising converter topologies is presented, leading to the choice of a magneticbased buck converter as a first conversion stage followed by an on-chip switched capacitors converter. An overall efficiency above 80% is estimated for the practical implementation proposed. I. SLHC POWER DISTRIBUTION NEEDS In the design of upgraded trackers for SLHC, the required increase in the number of readout channels should not lead to a heavier tracker. Since cables and cooling are amongst the main contributors to the material budget, and they are both dependent on the amount of power burnt in the tracker, ondetector power management is necessary. It is important to both decreasing the power per function ratio of Front-End (FE) electronics, and to distributing the power efficiently. The first objec...

Retificadores de alta qualidade com comutação em alta ou em baixa frequência - um estudo comparativo

Eletrônica de Potência, 2001

Comparison between two single-switch isolated flyback and forward high-quality rectifiers for low power applications

APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335)

In this paper, two isolated single-switch high-quality rectifiers are compared: one is based on t... more In this paper, two isolated single-switch high-quality rectifiers are compared: one is based on the forward topology with secondary side resonant reset, the other is a flyback rectifier with a lossless passive snubber. These rectifiers were both designed for universal input voltage range (90 ÷ ÷ ÷ ÷ 260 V RMS) and 200 W nominal output power. The adopted control technique is a modified non-linear carrier control based on the integration of the switch current signal, which does not require any input voltage sensing, analog multiplier and current error amplifier. The comparison is based both on theoretical analysis and measurements on fully developed prototypes and takes into account the following aspects: basic design guidelines, voltage and current rating of active devices, power losses on the main devices, overall efficiency and conducted EMI generation. This work, highlighting advantages and drawbacks of both the selected topologies, will allow designers to make a proper choice for a given application in the low power range (below 300W).

Analysis of the active-clamped soft-switched forward converter without output filter

2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551)

This paper analyzes an active-clamped softswitched forward converter without output filter. Diffe... more This paper analyzes an active-clamped softswitched forward converter without output filter. Differently from the topology presented in 111, the transformer reset is obtained by using an active clamp subcircuit instead ofa lossless passive snubber. This solution avoids the use of a second inductor and auxiliary diodes and allows a better exploitation ofthe converter components, since now both the main and the auxiliary switch turn on at zero voltage and zero current, and they turn off at zero voltage by using a loss-less capacitor. The resulting topology is practically identical to that of an activeclamped flyback converter, except for the reversed transformer secondary side polarity. Thus, in addition to the converter analysis, the paper presents a comparison between the proposed converter and the active-clamped flyback converter, by testing two prototypes rated for 48W output power.

Digital Control in Power Electronics, 2nd Edition

Synthesis Lectures on Power Electronics, 2015

Synthesis Lectures on Power Electronics will publish 50-to 100-page publications on topics relate... more Synthesis Lectures on Power Electronics will publish 50-to 100-page publications on topics related to power electronics, ancillary components, packaging and integration, electric machines and their drive systems, as well as related subjects such as EMI and power quality. Each lecture develops a particular topic with the requisite introductory material and progresses to more advanced subject matter such that a comprehensive body of knowledge is encompassed. Simulation and modeling techniques and examples are included where applicable. e authors selected to write the lectures are leading experts on each subject who have extensive backgrounds in the theory, design, and implementation of power electronics, and electric machines and drives. e series is designed to meet the demands of modern engineers, technologists, and engineering managers who face the increased electrification and proliferation of power processing systems into all aspects of electrical engineering applications and must learn to design, incorporate, or maintain these systems.

A low-loss high-power-factor flyback rectifier suitable for smart power integration

2000 IEEE 31st Annual Power Electronics Specialists Conference. Conference Proceedings (Cat. No.00CH37018), 2000

A low-loss, high-power-factor flyback rectifier is presented, which is designed as a possible app... more A low-loss, high-power-factor flyback rectifier is presented, which is designed as a possible application for a new type of smart power integrated circuit. This is going to be manufactured by ST Microelectronics using the VIPower © M3 technology and will include on the same silicon chip both control circuitry and an emitter switching power device. In order to avoid dangerous interactions between power and control part of the integrated circuit, it is necessary to control the rate of change of the power device voltage at turn-off. Accordingly, a lossless passive snubber was added to the conventional converter topology. The snubber also limits the voltage spikes across the power device, due to the transformer leakage inductance, and reduces the electromagnetic noise generation. A modified non-linear carrier control is considered which, thanks to the integration of the switch current signal, ensures high power factor and inherent noise immunity together with a simple control implementation (no need of input voltage sensing, multiplier and current error amplifier). A 200 W converter prototype was tested in order to evaluate the achievable performance.

Susceptibility of integrated circuits to RFI: analysis of PWM current-mode controllers for SMPS

IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02

This paper deals with the analysis of the effects of radio frequency conducted interfering signal... more This paper deals with the analysis of the effects of radio frequency conducted interfering signals (RFI) on integrated circuits (IC's). After reviewing the basic results of the susceptibility analysis of operational amplifiers and smart power integrated circuits, the behavior of several pin-to-pin compatible control IC's for PWM current-mode switching power supplies (SMPS) has been tested in the presence of both continuous wave interfering signals (CW) as well as of pulsed noise signals (underground condition). The tested ICs were selected between some common models available on the market. The variations of the primary functional parameters (inner voltage reference, switching frequency, etc.) are evaluated in different test conditions. The paper gives a comparative view of the results, focusing on the key macroscopic effects.

Power factor preregulator based on modified tapped-inductor buck converter

1998 International Conference on Power Electronic Drives and Energy Systems for Industrial Growth, 1998. Proceedings.

Power factor preregulators based on buck-type converters with capacitive output filter do not all... more Power factor preregulators based on buck-type converters with capacitive output filter do not allow a unity power factor due to their inability to draw current from the ac line during those intervals when the input voltage is lower than the output one. This limitation can be overcome by using a modified tapped-inductor buck topology, which can be arranged to operate as a flyback converter when desired. This modification, which requires only an extra line-frequency commutated switch and a diode, allows to extend the input current conduction angle, thus making the converter compliant with harmonic standards like IEC 1000-3-2. A 1kW converter has been designed, built and tested to validate the theoretical forecasts.

Conducted EMI issues in a boost PFC design

INTELEC - Twentieth International Telecommunications Energy Conference (Cat. No.98CH36263)

The paper presents the results of an experimental activity concerned with the development of a 60... more The paper presents the results of an experimental activity concerned with the development of a 600W Boost Power Factor Corrector (PFC) complying with the EMC standards for conducted EMI in the 150kHz-30MHz range. In order to accomplish this task, different circuit design and layout solutions are taken into account and their effect on the conducted EMI behavior of the converter is experimentally evaluated. Common-mode and differential-mode switching noise, together with input filters' design and topology and with the PCB layout (in terms of track length and spacing, ground and shielding planes etc.) are the key aspects which have been analyzed. In particular, the paper reports the conducted EMI measurements for different filter capacitor placements and values, for different power switch drive circuits together with several other provisions which have turned out to be decisive in the reduction of the generated EMI.

Single-phase AC/DC integrated PWM converter

INTELEC. Twenty-Second International Telecommunications Energy Conference (Cat. No.00CH37131), 2000

The paper proposes a new topology of a boost type ac/dc PWM converter featuring high power factor... more The paper proposes a new topology of a boost type ac/dc PWM converter featuring high power factor, full control of the output dc voltage and high-frequency line filter inductor and insulation transformer. Its main advantage is the complete integration of a rectifier and an inverter stage, so that a compact converter with only four IGBT's and six diodes is obtained. The integration poses some constraints on the line current control capability of the converter, which is limited. Nevertheless, the compliance with EMC standards (IEC 61000-3-2) is possible for a wide load range. The paper presents a detailed analysis of the topology, highlighting the design constraints and proposes a possible design procedure, which is then verified by means of numerical simulations.

Power factor preregulators based on combined buck-flyback topologies

IEEE Transactions on Power Electronics, 2000

The limitation imposed on the achievable power level by the IEC 1000-3-2 standard in buck-derived... more The limitation imposed on the achievable power level by the IEC 1000-3-2 standard in buck-derived power factor preregulators, is overcome by using a combined buck-flyback power stage. Two different step-down converters are proposed in this paper, which incorporate an auxiliary flyback stage. The auxiliary stage uses the same switch of the main converter, plus an additional power switch commutated at the line frequency. As compared to a simple buck rectifier, with this solution the harmonic content of the absorbed line current, at a given power level, can be reduced, thanks to the resulting increased conduction angle of the input rectifier bridge. Experimental results based on a 1 kW prototype are reported to validate the theoretical analysis of the proposed topologies.

Optimization of Shielded PCB Air-Core Toroids for High-Efficiency DC–DC Converters

IEEE Transactions on Power Electronics, 2011

The paper describes the design of optimized printed circuit board (PCB) air-core toroids for high... more The paper describes the design of optimized printed circuit board (PCB) air-core toroids for high-frequency dc-dc converters with strict requirements in terms of volume and noise. The effect of several design parameters on the overall inductor volume, on dc and ac winding resistance, and on the radiated noise will be investigated. PCB toroids are compared to standard air-core solenoids and other state-of-the-art air-core toroids both theoretically and experimentally: at first, using ANSOFT Maxwell and ANSOFT Q3D simulation tools, and subsequently, with laboratory measurements (irradiated noise, efficiency, and frequency response) on several prototypes. These very flexible and rather easy to manufacture inductors appear very attractive for compact highfrequency dc-dc converters where high efficiency, low volume, and low noise are of primary concern.