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EPE 2009 - Subtopic 16-3 - DS: 'Power Supplies'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 16: 'Power Supplies' > EPE 2009 - Subtopic 16-3 - DS: 'Power Supplies'
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	A complete analytical switching losses model for power MOSFETs in low voltage converters   By Miguel RODRÍGUEZ, ALBERTO RODRÍGUEZ, pablo FERNÁNDEZ, Javier SEBASTIÁN	[View]   [Download]
Abstract: This paper presents a complete analytical switching loss model for power MOSFETs in low voltage switching converters. Traditionally, the piecewise linear model has been used to obtain both switching losses and efficiency in these converters, due to its simplicity and good performance. However, the use of the latest low voltage power MOSFET generations and the continuous increase of the switching frequencies have made necessary to review this model to account for the parasitic inductances that were not included into it. The switching loss model presented in this paper includes all the parasitic inductances; it clarifies the switching process and provides information about how these inductances determine the switching behavior and the final converter efficiency. The analysis presented in this paper also yields two different types of possible switching situations: capacitive-determined switching and inductive-determined switching. In the former the piecewise linear model can be applied, while in the latter the proposed model is more accurate. Carefully-obtained experimental results that will be described in detail support the analytical results presented.
	A Derivative PWM Control Method with Constant Switching Frequency   By Takashi NABESHIMA, Min LIN, Terukazu SATO, Kimihiro NISHIJIMA	[View]   [Download]
Abstract: A derivative PWM control method with constant switching frequency strong against incoming switching noise is proposed. The triangular voltage obtained from a simple RC network as a comparator input is employed to determine the duty ratio and an external clock signal is used to fix the switching frequency. Applying the proposed method to the buck converter, excellent dynamic performances and stable switching action are realized.
	A Partial-Resonant Tapped-Inductor Converter with an Auxiliary Switch   By kimihiro NISHIJIMA, takashi INOUE, kosuke HARADA, michihiko NAGAO, Takashi NABESHIMA, terukazu SATO	[View]   [Download]
Abstract: A partial-resonant tapped-inductor converter with an auxiliary switch is proposed. The circuit construction is the same as a conventional tapped-inductor converter with active clamp circuit, but the drive timing for the auxiliary switch is different from the conventional one. As a result the output stability is improved as compared with the conventional active clamp one. Furthermore, zero current switching is achieved by a partial resonant with an auxiliary capacitor and the leakage inductance of the tapped-inductor during the on period of the auxiliary switch. The operating and performance of the proposed approach were verified experimentally by a laboratory prototype of 24V input to 1.0V output at 600kHz. As a result, 2\% improvement of efficiency is achieved.
	A study of Autonomous Decentralized Single Phase UPS System using Dynamic Reconfigurable Processor   By TOMOKI YOKOYAMA, Shinsuke OIDA	[View]   [Download]
Abstract: A new digital control system using Dynamic Reconfigurable Processor (DRP) was proposed for an au- tonomous decentralized UPS system. Recently, DRP was developed and released to the consumer mar- ket. DRP has the dynamic reconfigurable features to change the plural calculation circuit configuration in one clock duration. So the resource cost and the power cost of the processor can be decreased without the trade off of the calculation performance. In the future, DRP has the possibility to become one effec- tive solution for the power electronics applications. In this paper, DRP is applied for the controller of the autonomous decentralized single phase UPS system, the design concept of the system were described and the consideration of the resource consumption were discussed.
	Active phase shift control of multi-phase converters with coupled inductors to minimize input current sub-harmonics   By Sebastian UTZ, Michael STADLER, Johannes PFORR	[View]   [Download]
Abstract: Tolerance parameters limit the ripple cancellation phenomenon of an interleaving concept in multiphase converters. An analysis has been performed to demonstrate that coupled inductors help to reduce the influence of non-uniform inductances. Non-equal duty cycles and non-ideal phase-shifts are therefore more problematic in multi-phase converters with coupled inductors. This paper presents a control concept to optimize the phase-shifts and equalize the single pulse-widths especially for converters with coupled inductors. A prototype converter has been built and tested to show that filter components can be reduced with the proposed control technique. Theoretical predictions are compared with measurements on a full-size automotive dc-dc converter with six interleaved phases.
	Agent-Based Control of Parallel DC-DC Converters   By Janos HAMAR	[View]   [Download]
Abstract: The paper describes a new agent-based, decentralized architecture and control for parallel dc-dc converters, supplying low and moderate power consumers in the range of 0-250W. The system provides increased flexibility with autonomic system reconstruction capability in the case of misoperation or fault, significantly contributing to the increase of reliability. The distributed intelligence facilitates the optimization of the converters’ operation according to predefined criteria.
	An Improved Full Bridge Converter with Multiple Outputs for Barrier Discharge and U.V. Lamp Ballast   By JU WON BAEK	[View]   [Download]
Abstract: In this paper, an improved full bridge converter is presented to get multiple outputs for UV lamp and barrier discharge tube. It has a structure of two equivalent half bridge inverters that make one full bridge inverter. The proposed circuit has two types of outputs that are for U.V. lamp and the barrier discharge tube. The output can be controlled using frequency and PWM independently. To verify the proposed circuit, theoretical analysis and experimental results has been done using a prototype 250W power supply.
	Analysis, Design and Implementation of a Three-Phase AC to DC Converter    By UTHEN KAMNARN, Surasak YOUSAWAT, Yutthana KANTHAPHAYAO, Viboon CHUNKAG	[View]   [Download]
Abstract: The paper presents an implementation and control of a high power-factor and fast dynamic transient response of the modular three-phase ac to dc converter using three CUK rectifier modules with a small dc bus capacitor. The methodology aims at finding the small dc bus capacitor which meets the desired system performance, with power balance control technique. Modeling a modular three-phase rectifier system is considered as the first step in the optimal sizing procedure. In this paper, mathematical average small-signal model for characterizing modular three-phase rectifier is proposed. Design of an analog controller for a small dc bus capacitor based modular three-phase rectifier is presented. The controller senses the parameters of the proposed system, and makes decisions about reject load and input voltage disturbances. The second step consists in minimize the sizing of the dc bus capacitor according to the transient response of dc bus output voltage and the delivered energy of capacitor concepts. Considering various types and capacities of dc bus capacitor, which can meet the desired system performance, are obtained by changing the type and size of the dc bus capacitors. The proposed system with the dc bus capacitor 470 μF gives the optimal choice. A 750W laboratory prototype with 470 μF is implemented and tested to verify the feasibility of the proposed system. The experimental results show that the proposed system, meet the desired system performance. Therefore the system choice plays an important role in cost reduction.
	Application of Dynamic Hysteresis Band Height Control to Improve Output Voltage Transient in Boost and Positive Buck-Boost Converters   By Arash BOORA, Firuz ZARE, Arindam GHOSH	[View]   [Download]
Abstract: This paper presents dynamic hysteresis band height control to reduce the overshoot and undershoot issue on output voltage caused by load change. The converters in this study are Boost and Positive Buck-Boost (PBB) converters. PBB has been controlled to work in a step up conversion and avoid overshoot when load is changed. Simulation and experimental results have been presented to verify the proposed method.
	Calculation of Motor Surge Voltage under the use of a Surge Suppression Cable   By Toshihisa SHIMIZU	[View]   [Download]
Abstract: This paper presents a novel motor surge voltage suppression system which utilizes a newly developed surge suppression cable. The feature of the system is that the surge suppression cable is connected in parallel with the motor terminal those independent from the main cable, and there is no need to connect any passive filter component for suppressing the motor surge voltage. The advantage of this method is that the current capacity of the surge suppression cable does not influenced by the power capacity of the motor drive system. Hence the diameter of the surge suppression cable can be very small, and the surge suppression cable can be included in the main cable sheath. A mechanism of the motor surge suppression on the present system is demonstrated, and also the numerical equation for motor surge voltage is derived by taking the surge voltage transmission phenomenon on the cables into account. The calculated results are coincide well with the experimental results, and the usefulness of the proposed system are verified thorough the 750W ac drive experimental setup.
	Capacitor Design Issues for Buck Boost and Flyback Converters   By Michael BIERHOFF	[View]   [Download]
Abstract: To aid capacitor design for the most common topologies of switched mode power supplies, that is buck boost and flyback converters, an analytical approach to determine the RMS value of the ripple current and the peak-to-peak value of DC ripple voltage of the output capacitance is presented for the entire operation range. Hence the presented formulae facilitate capacitor design for this common DC-converter topology in terms of competitive aims such as maximum life cycle and minimal voltage ripple versus minimal cost and space.
	Current source as a power supply unit for an electric discharge machine   By Wojciech MYSINSKI	[View]   [Download]
Abstract: The electrical discharge machining process provides one of the best solutions available for machining a growing number of high-strength and corrosion –and-wear resistant materials. It operates on the principle of erosion of metal surfaces by an interrupted electric spark. The power supply design and configuration requirements for producing the desired spark have always been a challenge to the researchers. This paper presents an example of a configuration of a power supply used for the EDM process. The power supply (a pulse power generator) is based on an electronic current source utilising flyback converter and an electronic gap polarity switch. This article describes results of laboratory tests.
	Current-sharing technique for interleaving VRMs using intercell transformers   By Mathieu LE BOLLOCH, Marc COUSINEAU, Thierry MEYNARD	[View]   [Download]
Abstract: Parallel converter architecture using intercell transformers is one of the most adapted architecture for low-voltage, high-current and fast transient power conversion applications. Interleaved buck converter with intercell transformers main interest is the current ripple reduction in each converter arms which is not the case with non-coupled inductor architectures. As a consequence, current constraints on switches and inductors are less severe and lower Joule losses are obtained leading to a higher efficiency. This paper highlights a fundamental limitation for those interleaved converters using intercell transformers. A differential current error through intercell transformers causes flux drift and can lead to magnetic core saturation. In case of temporary control failure, arm currents get back to proper balance with a very slow dynamic response. State-space study allows us to calculate arm current transfer function and deduce the differential current time constant. Finally, a stability study with standard filters is presented and a proper current-sharing loop regulator filter is proposed in order to speed up system return to equilibrium.
	Development of a 10 kW High Power Density Three-Phase AC-DC-AC Converter Using SiC Devices   By Rixin LAI, Fred WANG, Puqi NING, Rolando BURGOS, Boroyevich DUSHAN, Vikram D. IMMANUEL, Kamiar J. KARIMI	[View]   [Download]
Abstract: This paper presents the development and experimental performance of a 10 kW high power density three-phase ac-dc-ac converter. The converter consists of a Vienna-type rectifier front-end and a two-level voltage source inverter (VSI). In order to reduce the switching loss and achieve a high operating junction temperature, a SiC JFET and SiC Schottky diode are utilized. Design considerations for the phase-leg units, gate drivers, integrated input filter—combining EMI and boost inductor stages—and the system protection are described in full detail. Experiments are carried out under different operating conditions, and the results obtained verify the performance and feasibility of the proposed converter system.
	Dynamic Study of Time Constant in High Intensity Discharge Lamps   By MARIO JUAREZ, MARIO PONCE, JAIME ARAU, EFREN FLORES, RENE OSORIO, Leobardo HERNANDEZ	[View]   [Download]
Abstract: Recent publications have established that the lamp time constant is an important factor to determine the stability of the lamp-ballast system. Different tests based on step response have been employed to obtain the dynamic characteristics of the lamp. These tests consist on applying a current or voltage pulse in order to obtain the lamp time constant. Nevertheless, a study that determines if the lamp time constant is the same in both cases has not been developed yet. On the other hand, the lamp time constants only have been tested in a single operation point, ignoring the effect of the limiting impedance (ballast). This paper presents a study about the lamp time constants and the interaction between time constants and ballast. This study concludes that the dominant dynamics of the lamp are determined by the gas thermal constant, which is extracted from the lamp current.
	High Efficiency DC-DC Converter using a Series-Parallel Compensation Method for a Fuel Cell   By Koji ORIKAWA, Jun-ichi ITOH	[View]   [Download]
Abstract: This paper proposes a novel DC-DC converter for a hybrid power supply using both a fuel cell and a battery. In the proposed circuit, the power converter with the battery is connected in series to the fuel cell. The output voltage is controlled by a series converter that regulates only the differential voltage between the fuel cell voltage and the output voltage. The power rating of conventional buck-boost DC-DC converters are dominated by the input voltage or the output voltage. In contrast, since the voltage rating of the proposed circuit requires the differential voltage between the fuel cell voltage and the output voltage, the power rating of the proposed circuit is smaller than that of the conventional converters. In addition, in order to suppress large current ripple in the fuel cell, a parallel converter is added to the series converter. The experimental results confirmed that the proposed circuit could achieve 98.8\% at the maximum efficiency point in the small differential voltage region.
	High Power–Factor Resonance–Free Electronic Ballast Based on Integration Techniques to Drive High Intensity Discharge Metal Halide (HID–MH) Lamps   By andre luiz FUERBACK, CICERO DA SILVEIRA POSTIGLIONE, ARNADO JOSÉ PERIN, CLAUDINOR BITENCOURT NASCIMENTO	[View]   [Download]
Abstract: This work presents a two stage converter to drive high intensity of discharge metal halide lamps (HID-MH). The integration of two boost converters, in an interleaved way, with a full bridge inverter and the use of a square current waveform applied to the lamp results in high power factor and absence of acoustic resonance.
	High-Resolution Digital PWM Controller for High-Frequency Low-Power SMPS   By Shuibao GUO	[View]   [Download]
Abstract: This paper proposes a high-resolution Digital-PWM (DPWM) architecture for high-frequency low-power Switching Mode Power Supply (SMPS). The proposed DPWM takes advantage of Digital Clock Man- ager (DCM) phase-shift characteristics available in FPGA, and combines a counter-comparator with a Multi-stAge-noise-SHaping (MASH) Delta-Sigma (Δ-Σ) modulator. An 11-bit effective prototype DPWM along with a digital PID control algorithm are experimentally verified by using a Virtex-II FPGA on a discrete low-power buck converter. Experimental results with constant switching frequency up to 4MHz validate the functionality of the proposed DPWM. In addition, the digital controller is imple- mented in a 0.35 µm standard CMOS.
	Optimization of PWM Dead Times in DC/DC-Converters considering varying Operating Conditions and Component Dependencies   By Tomas REITER, Dieter POLENOV, Hartmut PRÖBSTLE, Hans-Georg HERZOG	[View]   [Download]
Abstract: PWM dead time related power losses degrade the converter efficiency, especially at low bus-voltages and high switching frequency. A reduction of these losses can be achieved by sensorless PWM dead time optimization approaches. In order to derive an optimization algorithm it is necessary to know the influence of dead times on the switching behavior and related power losses. This paper focuses on the reverse recovery charge for varying dead times and different MOSFET devices. Further experiments show, that there is an operating point dependency in optimal dead times. This is caused by a parasitic half-bridge capacitance. A behavioral model is derived from these experimental results. The model shows the quantitative influence of dead times on power losses. It is compared with measurements of the converter efficiency.
	Potential of improving PWM Converter Power Density with Advanced Components   By Yi WANG, J. A. FERREIRA, S.W.H. DE HAAN	[View]   [Download]
Abstract: High power density power electronics converters are increasingly demanded. Generally speaking, raised switching frequency improves the power density. However, dramatically increasing frequency on the present level still depends on the advance of power electronic components in material property, packaging technique, thermal management technique and etc. This paper surveys the recent material development of key components in the PWM power converters and then try to quantify the potential of improving the system power density by using advanced components. For illustrating this potential, power densities of air-cooled dual active bridge DC-DC converters (12V-360V, 1 kW) with three categories of components are analyzed and compared, namely state-of-art components, available advanced components and future components. The future components assume ten times better loss-related properties than those of the advanced components currently available.
	Recovery-less Boost Converter for Electric Vehicle   By takahiro KAWASHIMA, hiroyuki HORII, masayoshi YAMAMOTO, shigeyuki FUNABIKI, hideki ASUKE, shuji TAKANO, masaki KANAZAWA	[View]   [Download]
Abstract: The miniaturization and higher efficiency performances of boost converter for Electric Vehicle have been required. In this paper, a novel trans-linked recovery-less boost converter, which can reduce the size of the main inductor for the boost operation and can solve diode recovery problem without the additional active power switch is proposed. The size reduction of the main inductor is realized by interleaving and trans-linked techniques. And suppressing diode recovery phenomenon is realized by the additional inductor because the current transition through the diodes is softly. Furthermore, zero current switching (ZCS) can be achieved as well in active switches at turn-on. Therefore the switching loss in active switching devices is also reduced. The additional inductor is required optimum design to suppress diode recovery phenomenon effectively. This paper describes the design theory of additional inductor and transformer turn ratio. The fundamental operation of the proposed boost converter is described and confirmed on the basis of the experimental results. In the experimental results, suppressing diode recovery and realizing ZCS operation is confirmed actually. As a result, the proposed circuit achieves 0.4\% higher efficiency as compared with one of conventional circuit. As future trends, reverse buck topology is presented for practical aspect.
	The Influence of Turn-Off Dead Time on the Reverse-Recovery Behaviour of Synchronous Rectifiers in Automotive DC/DC-Converters   By Dieter POLENOV, Tomas REITER, Roman BABURSKE, Hartmut PROEBSTLE, Josef LUTZ	[View]   [Download]
Abstract: The current commutation from the channel into the body diode of a MOSFET synchronous rectifier as well as the relation of the PWM turn-off dead time and its reverse-recovery behaviour were simulated and investigated experimentally. Both, reverse-recovery charge and current can be reduced significantly by shortening the dead time to few 10 ns. It leads to an overall converter loss reduction of several percent. The improvement of the reverse-recovery behaviour is based on the turn-on dynamics of the diode. In the considered case it takes several 10 ns to enhance plasma in the n–-region of the body diode. Therefore, turning off of the synchronous rectifier before the plasma has reached a steady-state will lead to a lower reverse-recovery charge.
	Triple-Hybrid Spread-Spectrum Technique for Conducted-Noise Reduction in DC-DCConverters with an FPGA-Based Implementation   By GAMAL M. DOUSOKY, Masahito SHOYAMA, Tamotsu NINOMIYA	[View]   [Download]
Abstract: A novel technique for conducted-noise reduction has been proposed in this paper. The proposed technique uses three randomized parameters for generating the switching signals. These parameters are carrier frequency, duty-ratio, and the pulse position. This triple-hybrid spread-spectrum technique has been designed and implemented using field-programmable gate array (FPGA) technology. Moreover, the effect of using the proposed controller on common-mode and differential-mode noise, total conducted-noise, and radiated-noise characteristics of the converter has been experimentally investigated. Furthermore, sweeping of the three randomization parameters has been carried-out for reaching the values which achieve the best conducted-noise spectrum spreading. All the 64 studied cases have been designed, implemented and experimentally investigated. Then, the conducted-noise spectrums have been compared. The experimental results show that using the proposed technique, with the reached randomization parameter values, significantly improves the conducted-noise spectrum and effectively reduces the noise peaks at both high and low frequency ranges. Moreover, the radiated-noise spectrum has been improved.