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1

FRACTIONAL ORDER SMC FOR DC-DC BUCK CONVERTER

This paper proposed a fractional order sliding mode control for DC-DC buck converter. The traditionally P, PI and PID type linear controllers are used to control the voltages. The DC-DC buck converter is nonlinear and time variant in nature. To control such system variable structure control based sliding mode controller (SMC) is used. The fractional order sliding mode control method not only eliminates chattering problem of integer order SMC, it gives good transient response of the system. Th...

Jagdale, S. D.; Nagarale, R. M.

2013-01-01

2

FRACTIONAL ORDER SMC FOR DC-DC BUCK CONVERTER

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposed a fractional order sliding mode control for DC-DC buck converter. The traditionally P, PI and PID type linear controllers are used to control the voltages. The DC-DC buck converter is nonlinear and time variant in nature. To control such system variable structure control based sliding mode controller (SMC is used. The fractional order sliding mode control method not only eliminates chattering problem of integer order SMC, it gives good transient response of the system. The simulation results shows fractional order SMC gives fast response compared to integer order SMC.

S. D. Jagdale

2013-11-01

3

Study of Sliding Mode Control of DC-DC Buck Converter

In this paper, a robust sliding mode controller for the control of dc-dc buck converter is designed and analyzed. Dynamic equations describing the buck converter are derived and sliding mode controller is designed. A two-loop control is employed for a buck converter. The robustness of the sliding mode controlled buck converter system is tested for step load changes and input voltage variations. The theoretical predictions are validated by means of simulations. Matlab/Simulink is used for the ...

Hanifi Guldemir

2011-01-01

4

Charger for NiMH batteries based on buck DC/DC converter

In this paper is presented charger for NiMH battery types AA. Charger is realized by Buck DC/DC converter and microcontroller. Microcontroller controls the work of Buck DC/DC converter by pulse width modulation and by measuring the current of battery charging. The current of charging is held constant by power electronics, and the time of charging is set by the user dependent of capacity of the battery. Standard battery chargers enable the recharge of NiMH b...

Lap?evi? Vladimir

2014-01-01

5

Modeling and State Control of Switched Mode DC-DC Buck Converter

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents a design methodologyuseful to control DC-DC converters. As a practicalexample, the authors show how to design a controllerfor a switched mode DC-DC buck converter. Since theswitched mode power converters are nonlinear systems,the authors used the state space averaging techniquesto obtain a linear model for the buck converter. Theconverter operates in the steady state continuousconduction mode using the state control method. Incomparison with other control methods, such asvoltage mode control or current mode control, statecontrol technique is more precise because it uses allmain state values to increase the dynamicperformances of the power converter. The paperincludes simulation results that indicate the usefulnessfor possible future hardware implementation. Theauthors used in requested computations for themodeling, control and simulation MATLABprogramming environment and SIMULINK. Thedesign methodology is useful also for convertors with amore complex topology than the DC-DC buckconverter, even if they operate in the case ofdiscontinuous conduction mode.

TRIP Nistor Daniel

2010-05-01

6

A novel bidirectional multilevel boost-buck dc-dc converter

A novel noninverting boost-buck dc-dc converter topology is presented, applicable when both sides of the converter need to have the same grounding. It is based on the back-to-back connection of two n-level diode-clamped converter legs, and allows bidirectional power flow. A simplified topology is proposed for unidirectional power flow applications. Two new pulse width modulation strategies with different advantages are proposed to operate the converter guaranteeing dc-lin...

Busquets Monge, Sergio; Alepuz Mene?ndez, Salvador; Bordonau Farrerons, Jose?

2009-01-01

7

Study of Sliding Mode Control of DC-DC Buck Converter

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a robust sliding mode controller for the control of dc-dc buck converter is designed and analyzed. Dynamic equations describing the buck converter are derived and sliding mode controller is designed. A two-loop control is employed for a buck converter. The robustness of the sliding mode controlled buck converter system is tested for step load changes and input voltage variations. The theoretical predictions are validated by means of simulations. Matlab/Simulink is used for the simulations. The simulation results are presented. The buck converter is tested with operating point changes and parameter uncertainties. Fast dynamic response of the output voltage and robustness to load and input voltage variations are obtained.

Hanifi Guldemir

2011-09-01

8

A New Zero Voltage Switching Buck-Boost Type DC-DC Converter

In this paper, a new zero voltage switching isolated buck-boost DC-DC converter with active clamp circuit is proposed. The active clamp circuit in this converter not only absorbs voltage spikes across the main switch but also provides soft switching conditions for all switches. All switches are PWM controlled which simplifies the control implementation. One of the main advantages of this converter is the that it operating can operate at high power levels while soft switching conditions exist ...

Majid Delshad

2010-01-01

9

Voltage Tracking of a DC-DC Buck-Boost Converter Using Neural Network Control

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes a neural network control scheme of a DC-DC Buck-Boost converter to produce variable DC voltage source that will be applied on DC motor drives. In this technique, a back propagation learning algorithm is derived. The controller is designed to track the output voltage of the DC-DC converter and to improve performance of the Buck-Boost converter during transient operations. Furthermore, to investigate the effectiveness of the proposed controller, some operations such as starting-up and reference voltage variations are verified. The numerical simulation results show that the proposed controller has a better performance compare to the conventional PI-Controller method.

W.M.Utomo,

2011-12-01

10

Charger for NiMH batteries based on buck DC/DC converter

Directory of Open Access Journals (Sweden)

Full Text Available In this paper is presented charger for NiMH battery types AA. Charger is realized by Buck DC/DC converter and microcontroller. Microcontroller controls the work of Buck DC/DC converter by pulse width modulation and by measuring the current of battery charging. The current of charging is held constant by power electronics, and the time of charging is set by the user dependent of capacity of the battery. Standard battery chargers enable the recharge of NiMH battery for few hundred times, because termination of charging is done when voltage drop on the battery is detected. The aim of this paper is to create charger which enables that NiMH battery is charged 1000 times.

Lap?evi? Vladimir

2014-01-01

11

Design of a PEM Fuel Cell Simulator Based on DC-DC Buck Converter

Modeling of fuel cells is getting more and more important as power fuel cell stacks being available and have to be integrated into real power systems. This paper presents a novel circuit simulator for a PEM fuel cell that can be used to design fuel cell based systems. The simulator is consisted of a DC-DC buck converter driven by PIC 16F877 microcontroller. The proposed circuit can be used in design and analysis of fuel cell power systems.

Georgi Georgievski; Arsov, Goce L.

2010-01-01

12

Renewable energy such as wind force and solar light has collected the attention as alternative energy sources of fossil fuel. An energy storage system with an electric double-layer capacitor (EDLC), which balances the demand and supply power, is required in order to introduce the electric power generating system that utilizes renewable energy. Currently, the research and development of these energy storage systems are actively carried out. In the energy storage system with an EDLC, the DC/DC converter having the function of the bidirectional power flow and the buck/boost performance is essential as an interface and power control circuit. There are two types of the bidirectional buck/boost DC/DC converters. One type consists of two buck/boost DC/DC converters with one reactor. The other type consists of two sets of two-quadrant DC/DC converters with one reactor. This paper discusses the comparison of these types of DC/DC converters with bidirectional power flow and buck/boost performance. The two types of DC/DC converters are estimated for their application to the energy storage system with the EDLC. As the voltage endurance of the device is lower and the mean current is smaller in the latter type of converter despite of having twice the number of devices compared to the former, the latter type of converter has the advantage of a smaller reactor, i.e., core volume and loss, and lower loss in the converter.

Funabiki, Shigeyuki; Yamamoto, Masayoshi

13

Directory of Open Access Journals (Sweden)

Full Text Available The two basic topologies of switch mode DC-DC converters (Buck and Boost are analyzed with a view of their use in PV (photovoltaic systems, as the photovoltaic generator exhibits non-linear characteristics due to the change in environmental condition and load variation. As the efficiency of PV panels is low it becomes mandatory to extract maximum power from the PV panel at a given period of time. Several MPPT algorithms with different types of converters are being proposed for extracting maximum power from the PV panel. It is found that the nature of load plays an important role in the choice of topology. This paper investigates the implementation issues of Incremental Conductance method with Buck and Boost Converters. Mathematical analysis and desirable steady-state operating point of the converters are derived to give satisfactory maximum power point tracking operation.

Dhananjay Choudhary

2014-08-01

14

DEFF Research Database (Denmark)

This paper presents and discusses design considerations and efficiency investigation of a conventional step-down and a hybrid switched-capacitor DC-DC converter. Three MOSFETs with low on-resistance have been tested for each converter in order to find the most adequate switch for this application. The experimental results and comparative efficiency graphs were obtained with a 1kW laboratory prototype dedicated for a 42/14V dual voltage automotive system.

Pelan, Ovidiu; Cornea, Octavian

2014-01-01

15

Many Embedded Systems are indeed Software Based Control Systems (SBCSs), that is control systems whose controller consists of control software running on a microcontroller device. This motivates investigation on Formal Model Based Design approaches for automatic synthesis of SBCS control software. In previous works we presented an algorithm, along with a tool QKS implementing it, that from a formal model (as a Discrete Time Linear Hybrid System, DTLHS) of the controlled system (plant), implementation specifications (that is, number of bits in the Analog-to-Digital, AD, conversion) and System Level Formal Specifications (that is, safety and liveness requirements for the closed loop system) returns correct-by-construction control software that has a Worst Case Execution Time (WCET) linear in the number of AD bits and meets the given specifications. In this technical report we present full experimental results on using it to synthesize control software for two versions of buck DC-DC converters (single-input and ...

Mari, Federico; Salvo, Ivano; Tronci, Enrico

2011-01-01

16

Integrated Circuit of CMOS DC-DC Buck Converter with Differential Active Inductor

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we propose a new design of DC-DC buck converter (BC, which the spiral inductor is replaced by a differential gyrator with capacitor load (gyrator-C implemented in 0.18um CMOS process. The gyrator-C transforms the capacitor load (which is the parasitic capacitor of MOSFETS to differential active inductor DAI. The low-Q value of DAI at switching frequency of converter (few hundred kHz is boosted by adding a negative impedance converter (NIC. The transistor parameters of DAI and NIC can be properly chosen to achieve the desirable value of equivalent inductance L (few tens H, and the maximum-Q value at the switching frequency, and thus the efficiency of converter is improved. Experimental results show that the converter supplied with an input voltage of 1V, provides an output voltage of 0.74V and output ripple voltage of 10mV at 155 kHz and Q-value is maximum (#8776;4226 at this frequency.

Kaoutar Elbakkar

2011-11-01

17

Integrated Current-Mode DC-DC Buck Converter with Low-Power Control Circuit

Directory of Open Access Journals (Sweden)

Full Text Available A low power CMOS control circuit is applied in an integrated DC-DC buck converter. The integrated converter iscomposed of a feedback control circuit and power block with 0.35 ?m CMOS process. A current-sensing circuit isintegrated with the sense-FET method in the control circuit. In the current-sensing circuit, a current-mirror is usedfor a voltage follower in order to reduce power consumption with a smaller chip-size. The N-channel MOS acts asa switching device in the current-sensing circuit where the sensing FET is in parallel with the power MOSFET. Theamplifier and comparator are designed to obtain a high gain and a fast transient time. The converter offers wellcontrolledoutput and accurately sensed inductor current. Simulation work shows that the current-sensing circuitis operated with an accuracy of higher than 90% and the transient time of the error amplifier is controlled within 75?sec. The sensing current is in the range of a few hundred ?A at a frequency of 0.6~2 MHz and an input voltage of 3~5 V.The output voltage is obtained as expected with the ripple ratio within 1%.

Nam-Soo Kim

2013-10-01

18

Switching frequency acts as a major role, while applying sliding mode control to dc-dc buck converter, switching frequency is affected by line and load variations. To reduce switching frequency deviation to line and load variations, an adaptive feed forward control is used, that varies hysteresis band according to the change of input voltage. Several methods of varying hysteresis band of the hysteresis modulator are possible. In this work adjusting the power supply is to be considered. An ada...

Nagaraj, H. N.; Rajanna, G. S.

2012-01-01

19

International Nuclear Information System (INIS)

This paper presents a width controller, a dead time controller, a discontinuous current mode (DCM) controller and a frequency skipping modulation (FSM) controller for a high frequency high efficiency buck DC-DC converter. To improve the efficiency over a wide load range, especially at high switching frequency, the dead time controller and width controller are applied to enhance the high load efficiency, while the DCM controller and FSM controller are proposed to increase the light load efficiency. The proposed DC-DC converter controllers have been designed and fabricated in the Chartered 0.35 ?m CMOS process, and the measured results show that the efficiency of the buck DC-DC converter is above 80% over a wide load current range from 8 to 570 mA, and the peak efficiency is 86% at 10 MHz switching frequency. (semiconductor integrated circuits)

20

Scientific Electronic Library Online (English)

Full Text Available En la última década se ha reportado la estrategia de control Zero Average Dynamics (ZAD) como una alternativa al control de los convertidores de potencia, garantizando frecuencia fija de conmutación y bajo error. Sin embargo la estabilidad del sistema depende fuertemente de la carga, por lo cual no [...] es robusto. Cuando se pierde la estabilidad la frecuencia fija de conmutación se pierde también. En este artículo se presenta la generalización de la técnica ZAD dentro del marco de la teoría de probabilidades. Usando este marco es posible recuperar el ZAD tal como ha sido analizado hasta ahora y se pueden generar nuevas estrategias de control, las cuales son más estables que las usadas en el ZAD. Por este motivo a esta técnica se le ha llamado Generalized Zero Average Dynamics (GZAD). Presentamos algunas simulaciones del GZAD aplicado a un convertidor de potencia reductor. Esta nueva estrategia no puede ser obtenida con el ZAD clásico. Las simulaciones numéricas muestran buen desempeño del controlador con bajo error de regulación y robustez ante cambio en la carga. Abstract in english The Zero Average Dynamics (ZAD) strategy has been reported in the last decade as an alternative for controlling power converters. This technique has the advantage of guaranteeing fixed frequency switching. However, the stability of the controller is highly dependent on the load value, and when the s [...] tability is lost, the fixed frequency switching is lost too. In this paper we generalize ZAD strategy using the probabilities framework through the expectation operator. Thus, we recover classical sliding mode control classical ZAD strategy, and new control methods can be defined, which are more stable than the others previously used. For this reason, this technique is entitled Generalized Zero Average Dynamics (GZAD). We will show several simulations regarding an application to a DC-DC Buck converter within the generalized ZAD strategy, which cannot be deduced from the classical ZAD. Numerical simulations show good regulation features and a wide range of stability.

FABIOLA, ANGULO GARCIA; GERARD, OLIVAR TOST; GUSTAVO ADOLFO, OSORIO LONDOÑO.

2011-04-01

21

Directory of Open Access Journals (Sweden)

Full Text Available Switching frequency acts as a major role, while applying sliding mode control to dc-dc buck converter, switching frequency is affected by line and load variations. To reduce switching frequency deviation to line and load variations, an adaptive feed forward control is used, that varies hysteresis band according to the change of input voltage. Several methods of varying hysteresis band of the hysteresis modulator are possible. In this work adjusting the power supply is to be considered. An adaptive feedback control scheme that varies the control parameters (i.e. sliding coefficient according to the change of output load is proposed. This paper presents a complete investigation into the problem and gives the effectiveness of the desired solutions. In this method implementing the proposed adaptive control strategies are discussed, simulation results gives that the adaptive control methods are capable of reducing the switching frequency variations, simulation have been done in MATLAB /Simulink to verify the results.

H. N. Nagaraj

2012-05-01

22

Optimizing the dynamics of a two-cell DC-DC buck converter by time delayed feedback control

A study of the dynamical behavior of a two-cell DC-DC buck converter under a digital time delayed feedback control (TDFC) is presented. Various numerical simulations and dynamical aspects of this system are illustrated in the time domain and in the parameter space. Without TDFC, the system may present many undesirable behaviors such as sub-harmonics and chaotic oscillations. TDFC is able to widen the stability range of the system. Optimum values of parameters giving rise to fast response while maintaining stable periodic behavior are given in closed form. However, it is detected that in a certain region of the parameter space, the stabilized periodic orbit may coexist with a chaotic attractor. Boundary between basins of attraction are obtained by means of numerical simulations.

Feki, M.; El Aroudi, A.; Robert, B. G. M.; Martínez-Salamero, L.

2011-11-01

23

Radiation Effects on DC-DC Converters

In this work, several DC-DC converters were designed and built. The converters are Buck Buck-Boost, Cuk, Flyback, and full-bridge zero-voltage switched. The total ionizing dose radiation and single event effects on the converters were investigated. The experimental results for the TID effects tests show that the voltages of the Buck Buck-Boost, Cuk, and Flyback converters increase as total dose increased when using power MOSFET IRF250 as a switching transistor. The change in output voltage with total dose is highest for the Buck converter and the lowest for Flyback converter. The trend of increase in output voltages with total dose in the present work agrees with those of the literature. The trends of the experimental results also agree with those obtained from PSPICE simulation. For the full-bridge zero-voltage switch converter, it was observed that the dc-dc converter with IRF250 power MOSFET did not show a significant change of output voltage with total dose. In addition, for the dc-dc converter with FSF254R4 radiation-hardened power MOSFET, the output voltage did not change significantly with total dose. The experimental results were confirmed by PSPICE simulation that showed that FB-ZVS converter with IRF250 power MOSFET's was not affected with the increase in total ionizing dose. Single Event Effects (SEE) radiation tests were performed on FB-ZVS converters. It was observed that the FB-ZVS converter with the IRF250 power MOSFET, when the device was irradiated with Krypton ion with ion-energy of 150 MeV and LET of 41.3 MeV-square cm/mg, the output voltage increased with the increase in fluence. However, for Krypton with ion-energy of 600 MeV and LET of 33.65 MeV-square cm/mg, and two out of four transistors of the converter were permanently damaged. The dc-dc converter with FSF254R4 radiation hardened power MOSFET's did not show significant change at the output voltage with fluence while being irradiated by Krypton with ion energy of 1.20 GeV and LET of 25.97 MeV-square cm/mg. This might be due to fact that the device is radiation hardened.

Zhang, De-Xin; AbdulMazid, M. D.; Attia, John O.; Kankam, Mark D. (Technical Monitor)

2001-01-01

24

A Novel Zero-Voltage-Switching PWM Full Bridge Dc-Dc Buck Converter

Introducing resonant inductance and clamping diodes into the full-bridge converter can eliminate the voltage oscillation across the rectifier diodes and increase the load range for zero-voltage-switching (ZVS) achievement. The resonant inductance is shorted and its current keeps constant when the clamping diode is conducting, and the clamping diode is hard turned-off, causing significant reverse recovery loss if the output filter inductance is relatively larger. This paper imp...

Pravin Subhash Pawar *; , Prof. Suryakant Pawar2

2014-01-01

25

International Nuclear Information System (INIS)

A synchronous buck DC—DC converter with an adaptive multi-mode controller is proposed. In order to achieve high efficiency over its entire load range, pulse-width modulation (PWM), pulse-skip modulation (PSM) and pulse-frequency modulation (PFM) modes were integrated in the proposed DC—DC converter. With a highly accurate current sensor and a dynamic mode controller on chip, the converter can dynamically change among PWM, PSM and PFM control according to the load requirements. In addition, to avoid power device damage caused by inrush current at the start up state, a soft-start circuit is presented to suppress the inrush current. Furthermore, an adaptive slope compensation (SC) technique is proposed to stabilize the current programmed PWM controller for duty cycle passes over 50%, and improve the degraded load capability due to traditional slope compensation. The buck converter chip was simulated and manufactured under a 0.35 ?m standard CMOS process. Experimental results show that the chip can achieve 79% to 91% efficiency over the load range of 0.1 to 1000 mA (semiconductor integrated circuits)

26

Scientific Electronic Library Online (English)

Full Text Available Se presenta el diseño estático de un convertidor reductor-elevador bidireccional con tres conmutadores y conexión en cascada. La principal aplicación del convertidor es la administración de baterías en sistemas de alimentación ininterrumpida, controlando el flujo de energía y regulando la tensión de [...] alimentación DC durante los diferentes modos de operación de la batería como fuente y sumidero. Abstract in english This paper shows a buck-boost converter static design with 3 switches and cascade connection. The main application of the converter is the battery management on uninterruptible power supplies, controlling energy flow and regulating the DC supply voltage for the different battery operation modes as s [...] ource and sink.

Marcela, González Valencia; Alfonso, Alzate Gómez.

2010-06-01

27

An Efficient DC- DC Converter with Bidirectional Power Flow

This paper introduces a Bi-directional DC-DC converter with adaptive fuzzy logic controller. Bidirectional power flow is obtained by same power components and provides a simple, efficient, and galvanically isolated converter. In the presence of DC mains the converter operates as buck converter and charges the battery. When the DC mains fails, the converter operates as boost converter and the down stream converter is fed by the battery. The power switches are controlled by Pulse Width Modulati...

Rajarajeswari, N.; Thanushkodi, K.

2008-01-01

28

SIMPLIFIED APPROACHES FOR CONTROLLING DC-DC POWER CONVERTERS

This paper represents the design procedures of different compensation schemes for voltage mode controlled (VMC) dc–dc switching converters. Proportional integral derivative (PID) controllers, Fuzzy logic controllers (FLC), parallel combination of PID and FLC, and FLC tuned by PI controller have been investigated. MATLAB software is used to depict the buck converter performance with each compensator type when it is electrically simulated, and analytically modeled using its equivalent transfe...

Abdel Aziz, M. M.; Mahfouz, A. A.; Khorshied, D. M.

2012-01-01

29

Hybrid battery with bi-directional DC/DC converter

Bi-directional buck-boost DC/DC converterfor hybrid battery is described in this paper. The firstpart of the paper is aimed at concept of hybrid battery;main advance compared to conventional accumulatoris explained there. Control circuit with UC3637 andpower circuit of the converter are described in thesecond part of the paper. Experimental results frommeasuring of converter are mentioned in the last part.

Dudrik, Jaroslav; Olejar, Martin; Beres, Toma?s?

2010-01-01

30

DC/DC Converter Stability Testing Study

This report presents study results on hybrid DC/DC converter stability testing methods. An input impedance measurement method and a gain/phase margin measurement method were evaluated to be effective to determine front-end oscillation and feedback loop oscillation. In particular, certain channel power levels of converter input noises have been found to have high degree correlation with the gain/phase margins. It becomes a potential new method to evaluate stability levels of all type of DC/DC converters by utilizing the spectral analysis on converter input noises.

Wang, Bright L.

2008-01-01

31

CMOS Integrated Capacitive DC-DC Converters

This book provides a detailed analysis of all aspects of capacitive DC-DC converter design: topology selection, control loop design and noise mitigation. Readers will benefit from the authors’ systematic overview that starts from the ground up, in-depth circuit analysis and a thorough review of recently proposed techniques and design methodologies. Not only design techniques are discussed, but also implementation in CMOS is shown, by pinpointing the technological opportunities of CMOS and demonstrating the implementation based on four state-of-the-art prototypes. Provides a detailed analysis of all aspects of capacitive DC-DC converter design; Analyzes the potential of this type of DC-DC converter and introduces a number of techniques to unleash their full potential; Combines system theory with practical implementation techniques; Includes unique analysis of CMOS technology for this application; Provides in-depth analysis of four fabricated prototypes.

Van Breussegem, Tom

2013-01-01

32

Full range ZVS DC-DC converter

International Nuclear Information System (INIS)

A 500 V, 24 Amp DC-DC converter with digital signal processor (DSP) based control and protection has been designed, fabricated and tested. Its power circuit consists of IGBT based single phase inverter bridge, ferrite transformer and diode rectifier. All IGBTs in the inverter bridge are operated in zero voltage switching (ZVS) mode to minimize switching losses thereby increasing the efficiency of the converter significantly. The efficiency of this converter is measured to be greater than 97% at full load. In a conventional full bridge inverter, typically ZVS is achieved under full load condition while at light load ZVS is lost. An auxiliary LC circuit has been intentionally incorporated in this converter to achieve ZVS even at light loaded conditions. Detailed simulation of the converter circuit is carried out and crucial waveforms have been presented in this paper. Microchip make dsPIC30F2020 DSP is employed to provide phase shifted PWMs to IGBTs in the inverter bridge. All the crucial parameters are also monitored by this DSP and in case of any unfavorable conditions, the converter is tripped off. Suitable experiments were carried out in this DC-DC converter under different loaded conditions and a close match between the simulated and experimental results were obtained. Such DC-DC converters can be connected in series or parallel for the development of solid state modular power supplies for various applications. (author)

33

Energy saving dc-dc converter circuit

International Nuclear Information System (INIS)

An energy saving dc-dc converter circuit is disclosed having two energy efficient means which operate in tandem, an energy conserving means and a voltage doubling means. These energy efficient means are applied in combination with elements commonly found in dc-dc converter circuits, namely an ac voltage generator, a transformer for stepping up the generated ac voltage, and means for storing the converted dc voltage. The energy conserving means is connected to the dc voltage storage means. It comprises a resettable inhibit circuit which cuts off the provision of dc voltage for conversion for a predetermined interval when the output of the converter exceeds a predetermined level. The voltage doubling means is reponsive to outputs of the inhibit circuit of the energy conserving means and the ac voltage generator. It provides a phase inverted waveform of the generated ac voltage on one of two leads to the ac voltage step-up transformer

34

An Efficient DC- DC Converter with Bidirectional Power Flow

Directory of Open Access Journals (Sweden)

Full Text Available This paper introduces a Bi-directional DC-DC converter with adaptive fuzzy logic controller. Bidirectional power flow is obtained by same power components and provides a simple, efficient, and galvanically isolated converter. In the presence of DC mains the converter operates as buck converter and charges the battery. When the DC mains fails, the converter operates as boost converter and the down stream converter is fed by the battery. The power switches are controlled by Pulse Width Modulation technique and the pulses are generated by the application of fuzzy logic with an adoption algorithm. The proposed converter is simulated using MATLAB and laboratory prototype was developed to validate the simulation results.

N.RAJARAJESWARI

2008-07-01

35

Hysteretic Current Controlled Zvs Dc/Dc Converter For Automobile

DEFF Research Database (Denmark)

A novel bi-directional dc-dc converter with ZVS and interleaving for dual voltage systems in automobiles is presented. A variable frequency extended band hysteretic current control method is proposed. In comparison with classical fixed frequency current control PWM, the reverse polarity peak current needed for ZVS operation is kept constant and no in excess circulating current losses at light load conditions are encountered. Inductor current ripple decreases with load reduction. Automatic changes in operation between buck and boost modes are accomplished without transient currents. Power circuit elements design is given. The four-stage interleaving is digitally controlled.

Cernat, M.; Scortarul, P.

2007-01-01

36

Improved Models for DC-DC Converters

To obtain high performance control of a dc-dc converter, a good model of the converter is needed. It is suitable to consider the load to be included in the converter model since it usually affects the dynamics. The load is often the most variable part of this system. If the load current and the output voltage are measured there are good possibilities to obtain a good model of the load on-line. Adaptive control can then be applied to improve the control. In peak current-mode ...

Johansson, Bengt

2003-01-01

37

Radiation-Tolerant DC-DC Converters

A document discusses power converters suitable for space use that meet the DSCC MIL-PRF-38534 Appendix G radiation hardness level P classification. A method for qualifying commercially produced electronic parts for DC-DC converters per the Defense Supply Center Columbus (DSCC) radiation hardened assurance requirements was developed. Development and compliance testing of standard hybrid converters suitable for space use were completed for missions with total dose radiation requirements of up to 30 kRad. This innovation provides the same overall performance as standard hybrid converters, but includes assurance of radiation- tolerant design through components and design compliance testing. This availability of design-certified radiation-tolerant converters can significantly reduce total cost and delivery time for power converters for space applications that fit the appropriate DSCC classification (30 kRad).

Skutt, Glenn; Sable, Dan; Leslie, Leonard; Graham, Shawn

2012-01-01

38

Sliding Mode Control of Dc-Dc Boost Converter

Control of Dc-Dc boost converter is a complex task due to the nonlinearity inherent in the converter and introduced by the external changes. A robust sliding mode controller for the control of Dc-Dc boost converter were described in this study. Dynamic equations describing the boost converter are derived and sliding mode controller is designed. The robustness of the sliding mode controlled boost converter system is tested for step load changes and input voltage variations. The computer-aided ...

Hanifi Guldemir

2005-01-01

39

A high switching frequency voltage-mode buck converter with fast voltage-tracking speed and wide output voltage range has been proposed. A novel error amplifier (EA) is presented to achieve a high DC gain and get high phase margin, including a resistor and capacitor net, a unit gain block and a high gain block. The investigated converter has been fabricated with GF 0.35 ?m CMOS process and can operate at 6 MHz with the output voltage range from 0.6 to 3.4 V. The experimental results show that the voltage-tracking speed can achieve 8.8 ?s/V for up-tracking and 6 ?s/V for down-tracking. Besides, the recovery time is less than 8 ?s while the load current suddenly changes 400 mA.

Miao, Yang; Baixue, Zhang; Yun, Cao; Fengfeng, Sun; Weifeng, Sun

2014-05-01

40

Study on stability of the voltage-mode DC-DC converters

International Nuclear Information System (INIS)

Stroboscopic maps for voltage-mode converters in the continuous conduction mode (CCM) are build up. The stability of one-periodic point is analyzed together with eigenvalues of Jacobian matrix of discrete-maps. The voltage-mode buck converter is taken as an example, and the results of theoretical analysis and numerical simulation coincide with each other, which shows that the stability analysis of the DC-DC converters is feasible using the discrete-map model. (authors)

41

Implementation of FPGA based Digital Controller for Controlling Chaos in DC/DC converters

This paper analyzes the subharmonics andchaos generated in closed loop pulse width modulatedDC/DC buck converter and suggests the implementationof Digital controller based on time delayed selfcontrolling feedback concept for stabilizing the chaosgenerated in such converter. FPGA based digitalcontroller is designed and implemented for controllingthe chaotic oscillations of nonlinear switching converters.An experimental FPGA prototype and an applicationspecific IC that employ new controller arc...

Ranjan, Vanaja; Logamani, Premalatha

2010-01-01

42

Coupled Inductor Based High Step-Up DC-DC Converter for Multi Input PV System

Directory of Open Access Journals (Sweden)

Full Text Available With the shortage of the energy and ever increasing of the oil price, research on the renewable and green energy sources, especially the solar arrays and the fuel cells, becomes more and more important. How to achieve high step-up and high efficiency DC/DC converters is the major consideration in the renewable power applications due to the low voltage of PV arrays and fuel cells. In this paper a coupled inductor dc-dc converter for photovoltaic system is proposed. The circuit configuration of the proposed converter is very simple. Thus, the proposed converter has higher step-up and step-down voltage gains than the conventional bidirectional dc–dc boost/buck converter. Under same electric specifications for the proposed converter and the conventional bidirectional boost/buck converter, the average value of the switch current in the proposed converter is less than the conventional bidirectional boost/buck converter. The operating principles have been applied to multi input photovoltaic system and outputs have been observed.

G. Shiny Vikram

2014-09-01

43

Early Oscillation Detection for DC/DC Converter Fault Diagnosis

The electrical power system of a spacecraft plays a very critical role for space mission success. Such a modern power system may contain numerous hybrid DC/DC converters both inside the power system electronics (PSE) units and onboard most of the flight electronics modules. One of the faulty conditions for DC/DC converter that poses serious threats to mission safety is the random occurrence of oscillation related to inherent instability characteristics of the DC/DC converters and design deficiency of the power systems. To ensure the highest reliability of the power system, oscillations in any form shall be promptly detected during part level testing, system integration tests, flight health monitoring, and on-board fault diagnosis. The popular gain/phase margin analysis method is capable of predicting stability levels of DC/DC converters, but it is limited only to verification of designs and to part-level testing on some of the models. This method has to inject noise signals into the control loop circuitry as required, thus, interrupts the DC/DC converter's normal operation and increases risks of degrading and damaging the flight unit. A novel technique to detect oscillations at early stage for flight hybrid DC/DC converters was developed.

Wang, Bright L.

2011-01-01

44

A New ZVS Nonisolated Bidirectional DC-DC Converter with Minimal Auxiliary Element

In this paper, a new nonisolated bidirectional buck–boost dc–dc converter is introduced. The proposed converter can be operated under ZVS condition and fixed switching frequency regardless of the direction of power flow. To provide ZVS condition for switches a simple auxiliary circuit is used, that consists of an auxiliary inductor and a coupled winding to main inductor. Due to ZVS operation of switches, the reverse recovery problem of the body diode of the switches does not occur. Moreov...

Nasrin Asadi Madiseh; Majid Delshad

2013-01-01

45

Modified Multiport Dc-Dc Converter Topology For Smart Grid

The development of a Solid State Transformer (SST) that incorporates a DC-DC multiport converter to integrate both photovoltaic (PV) power generation and battery energy storage is presented in this dissertation. The DC-DC stage is based on a quad active-bridge (QAB) converter which not only provides isolation for the load, but also for the PV and storage. The AC-DC stage is implemented with a pulse-widthmodulated (PWM) single phase rectifier. A unified gyrator-based average model is develope...

Dhamodharan Shanmugam

2013-01-01

46

International Nuclear Information System (INIS)

The discrete iterative map models of peak current-mode (PCM) and valley current-mode (VCM) controlled buck converters, boost converters, and buck–boost converters with ramp compensation are established and their dynamical behaviours are investigated by using the operation region, parameter space map, bifurcation diagram, and Lyapunov exponent spectrum. The research results indicate that ramp compensation extends the stable operation range of the PCM controlled switching dc-dc converter to D > 0.5 and that of the VCM controlled switching dc–dc converter to D < 0.5. Compared with PCM controlled switching dc–dc converters with ramp compensation, VCM controlled switching dc–dc converters with ramp compensation exhibit interesting symmetrical dynamics. Experimental results are given to verify the analysis results in this paper. (general)

47

Soft Commutated Three-Phase Dc-Dc Converter

Directory of Open Access Journals (Sweden)

Full Text Available High efficient DC-DC Converters find its application in electric power generation, transmission, distribution and Uninterruptable power supplies (UPS. Three phase converter system as compared with single phase converter system increases power density with reduced switching stresses, efficient usage of the transformer magnetic core and smaller filter design as the frequency of the system is higher. Inorder to make use of the above mentioned advantages a ZVS-PWM three- phase current-fed push-pull dc-dc converter with active clamping was developed. This converter topology allows the reuse of the energy from the leakage inductances and reduces the electromagnetic interferences (EMI. The topology was designed and simulated using MATLAB/SIMULINK. The input supply voltage used for the converter is 120V DC.

Silpa.P.T

2014-08-01

48

Soft Commutated Three-Phase Dc-Dc Converter

High efficient DC-DC Converters find its application in electric power generation, transmission, distribution and Uninterruptable power supplies (UPS). Three phase converter system as compared with single phase converter system increases power density with reduced switching stresses, efficient usage of the transformer magnetic core and smaller filter design as the frequency of the system is higher. Inorder to make use of the above mentioned advantages a ZVS-PWM three- phase current-fed push-p...

Silpa.P.T; Rajeenamol P.T

2014-01-01

49

Design and implementation of fully-integrated inductive DC-DC converters in standard CMOS

CMOS DC-DC Converters aims to provide a comprehensive dissertation on the matter of monolithic inductive Direct-Current to Direct-Current (DC-DC) converters. For this purpose seven chapters are defined which will allow the designer to gain specific knowledge on the design and implementation of monolithic inductive DC-DC converters, starting from the very basics.

Wens, Mike

2011-01-01

50

High-Conversion-Ratio Bidirectional DC–DC Converter With Dual Coupled Inductors

In this paper, a high-conversion-ratio bidirectional DC–DC converter with dual coupled inductors is proposed. In the boost mode, two capacitors are parallel charged and series discharged by the dual coupled inductors. Thus, high step-up voltage gain can be achieved with an appropriate duty ratio. In the buck mode, two capacitors are series charged and parallel discharged by the dual coupled inductors. The bidirectional converter can have high step-down voltage gain. The stress voltage of al...

Omid Khezri; Javad Javidan

2014-01-01

51

Sliding Mode Control of Buck Converter

DC-DC converters are used to convert DC voltage from one level to other. These converters are drastically used in industry as well as in research. One of the main limitations of these converters is unregulated supply of voltage and current. To overcome these problems there are various control techniques. This paper presents two such methods. This paper compares dynamic performance of buck Converter using PID controller and Sliding mode controller. Simulation of PI and Sliding mode control of ...

Nagulapati Kiran

2014-01-01

52

High efficiency interleaved bi-directional ZVS DC-DC converter

A high efficiency interleaved bi-directional ZVS DC-DC converter is presented in this paper. This converter can be operated in both buck and boost mode. CoolMOS is used as a power device to achieve low conduction losses and fast turn off. The value of inductance is selected such that the CoolMOS drain-to-source voltage always falls to zero before it turns on and ZVS is achieved. Multiphase interleaved inductors are used to achieve high power and low ripple currents. Converter is operated at 50kHz and MATLAB Simulink simulation is performed. 6kW prototype converter is implemented in buck mode and simulation results are verified.

Zafarullah Khan, M.; Mohsin Naveed, M.; Akbar Hussain, D. M.

2013-06-01

53

High efficiency interleaved bi-directional ZVS DC-DC converter

International Nuclear Information System (INIS)

A high efficiency interleaved bi-directional ZVS DC-DC converter is presented in this paper. This converter can be operated in both buck and boost mode. CoolMOS is used as a power device to achieve low conduction losses and fast turn off. The value of inductance is selected such that the CoolMOS drain-to-source voltage always falls to zero before it turns on and ZVS is achieved. Multiphase interleaved inductors are used to achieve high power and low ripple currents. Converter is operated at 50kHz and MATLAB Simulink simulation is performed. 6kW prototype converter is implemented in buck mode and simulation results are verified.

54

High Efficiency Interleaved Bi-Directional ZVS DC-DC Converter

DEFF Research Database (Denmark)

A High Efficiency Interleaved Bi-Directional ZVS DC-DC converter is presented in this paper. This converter can be operated in both buck and boost mode. CoolMOS is used as a power device to achieve low conduction losses and fast turn off. The value of inductance is selected such that the CoolMOS drain-to-source voltage always falls to zero before it turns on and ZVS is achieved. Multiphase interleaved inductors are used to achieve high power and low ripple currents. Converter is operated at 50kHz and MATLAB Simulink simulation is performed. 6kW prototype converter is implemented in buck mode and simulation results are verified.

Zafar Ullah Khan, M.; Mohsin Naveed, M.

2013-01-01

55

Multiple-output Class E Isolated dc-dc Converter

This paper presents a multiple output class-E isolated dc-dc converter that regulates the output voltages at fixed switching frequency. The two output converter is simulated at operating frequency of 5 MHz. The converter output power is 40 W and the output voltages are 15 V and 5 V. All the switches operate at zero voltage switching (ZVS) conditions for the full load range. The circuit configuration is simple with small passive components which reduce the size of the converter. The circuit al...

Pavlovic, Zoran; Oliver Rami?rez, Jesu?s Angel; Alou Cervera, Pedro; Garci?a Sua?rez, Oscar; Prieto López, Roberto; Cobos Ma?rquez, Jose? Antonio

2010-01-01

56

Digital Control Techniques for DC/DC power converters

The newest generation of processors for embedded applications requires high performance power supplies. As a matter of fact, the new generation of power supplies are based on high-speed switching DC/DC converters. The latest constraint makes very difficult the task to implement a real time control system based on low-performance controllers. This is the reason why FPGAs are becoming more and more popular for the construction of real time control systems. Nevertheless, the main problem of usin...

Marti?nez Garci?a-tenorio, Javier

2009-01-01

57

Design of DC-DC Converter for Flash Memory IPs

Directory of Open Access Journals (Sweden)

Full Text Available A DC-DC converter for flash memory IPs performing erasing by the FN (Fowler-Nordheim tunneling and programming by the CHEI (channel hot electron injection is designed in this paper. For the DC-DC converter for flash memory IPs using a dual voltage of VDD (=1.5V±0.15V/VRD (=3.1V±0.1V, a scheme of using VRD (Read Voltage instead of VDD is proposed to reduce the pumping stages and pumping capacitances of its charge pump circuit. VRD (=3.1V±0.1V is a regulated voltage by a voltage regulator with an external voltage of 5V, which is used as the WL activation voltage in the read mode and an input voltage of the charge pump. The designed DC-DC converter outputs positive voltages of VP6V (=6V, VP8V (=8V and VP9V(=9V; and a negative voltage of VM8V (=-8V in the write mode.

Li-yan Jin

2013-01-01

58

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: English Abstract in spanish Se propone una estructura de desvío activo para maximizar la producción de potencia en sistemas fotovoltaicos bajo condiciones irregulares de operación, comparando su eficiencia con soluciones individuales y distribuidas basadas en convertidores DC/DC convencionales. Los análisis y simulaciones real [...] istas demuestran las ventajas del nuevo convertidor de desvío activo sobre soluciones basadas en convertidores Boost, Buck y Buck-Boost. Abstract in english An active bypass structure is proposed to maximize the power production in photovoltaic modules under mismatched conditions. Its efficiency is compared with single and distributed maximum power point tracking solutions based on conventional DC/DC structures. The analysis and simulations performed un [...] der realistic assumptions demonstrate the benefits of the novel active bypass converter over solutions based on Boost, Buck or Buck-Boost converters.

Carlos Andrés, Ramos-Paja; Roberto, Gira; Eliana Isabel, Arango Zuluaga.

2012-09-01

59

Multiple Output ZVS DC/DC Converter Based on PWM

Directory of Open Access Journals (Sweden)

Full Text Available This project presents a soft-switching dc/dc converter with transformers connected in series to implement the features of ZVS, low voltage stress for MOSFETs. The converter has two half-bridge circuits connected in series to limit the voltage stress of MOSFETs at one-half of the input voltage. The output sides of four circuits are connected in series and parallel to primary circuit. The proposed multi output converter shows excellent performance in terms of its output regulation from no-load to full-load conditions and it also provides a multi output capability.

Olivia Ramya Chitranjan

2014-05-01

60

Modified Multiport Dc-Dc Converter Topology For Smart Grid

Directory of Open Access Journals (Sweden)

Full Text Available The development of a Solid State Transformer (SST that incorporates a DC-DC multiport converter to integrate both photovoltaic (PV power generation and battery energy storage is presented in this dissertation. The DC-DC stage is based on a quad active-bridge (QAB converter which not only provides isolation for the load, but also for the PV and storage. The AC-DC stage is implemented with a pulse-widthmodulated (PWM single phase rectifier. A unified gyrator-based average model is developed for a general multi-active-bridge (MAB converter controlled through phase-shift modulation (PSM. Expressions to determine the power rating of the MAB ports are also derived. The developed gyrator-based average model is applied to the QAB converter for faster simulations of the proposed SST during the control design process as well for deriving the state-space representation of the plant. Both linear quadratic regulator (LQR and singleinput-single-output (SISO types of controllers are designed for the DC-DC stage. A novel technique that complements the SISO controller by taking into account the cross coupling characteristics of the QAB converter is also presented herein. Cascaded SISO controllers are designed for the AC-DC stage. The QAB demanded power is calculated at the QAB controls and then fed into the rectifier controls in order to minimize the effect of the interaction between the two SST stages. The dynamic performance of the designed control loops based on the proposed control strategies are verified through extensive simulation of the SST average and switching models.

Dhamodharan Shanmugam

2013-10-01

61

Application of digital control techniques for satellite medium power DC-DC converters

The objective of this paper is to present a work concerning a digital control loop system for satellite medium power DC-DC converters that is done in Space Research Centre. The whole control process of a described power converter bases on a high speed digital signal processing. The paper presents a development of a FPGA digital controller for voltage mode stabilization that was implemented using VHDL. The described controllers are a classical digital PID controller and a bang-bang controller. The used converter for testing is a simple model of 5-20 W, 200 kHz buck power converter. A high resolution digital PWM approach is presented. Additionally a simple and effective solution of filtering of an analog-to-digital converter output is presented.

Skup, Konrad R.; Grudzinski, Pawel; Nowosielski, Witold; Orleanski, Piotr; Wawrzaszek, Roman

2010-09-01

62

A Novel Bidirectional DC-DC Converter With Flyback Snubber For Hybrid Electric Vehicles

Hybrid electric Vehicles combine the benefits of engine, electric motor and batteries to provide improved fueleconomy. A converter is needed in hybrid Electric Vehicle for charging and discharging of the batteries. So a charging anddischarging can be combined in one circuit topology known as bidirectional DC-DC converter. Here the output is completelyisolated from input, so an isolated bidirectional Dc-DC converter is used. In the bidirectional DC-DC converter, there occursovervoltage and ove...

Nair, Divya K.; ELIZABETH RAJAN

2013-01-01

63

Bi-Directional DC-DC Converter for PHEV Applications

Energy Technology Data Exchange (ETDEWEB)

Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.

Abas Goodarzi

2011-01-31

64

Direct switching control of DC-DC power electronic converters using hybrid system theory

Energy Technology Data Exchange (ETDEWEB)

A direct switching control (DSC) scheme for power electronics converters was described. The system was designed for use in both traditional and renewable energy applications as well as in electric drive vehicles. The proposed control scheme was based on a detailed hybrid system converter model that used model predictive control (MPC), piecewise affine (PWA) approximations and constrained optimal control methods. A DC-DC converter was modelled as a hybrid machine. Switching among different modes of the DC-DC converter were modelled as discrete events controlled by the hybrid controller. The modelling scheme was applied to a Buck converter. The DSC was used to control the switch of the power converter based on a hybrid machine model. Results of the study showed that the method can be used to regulate output voltage and inductor currents. The method also provides fast transient responses and effectively regulates both currents and voltage. The controller can be used to provide immediate responses to dynamic disturbances and output voltage fluctuations. 23 refs., 7 figs.

Zhao, J.; Lin, F. [Wayne State Univ., Detroit, MI (United States). Dept. of Electrical and Computer Engineering; Wang, C. [Wayne State Univ., Detroit, MI (United States). Dept. of Electrical and Computer Engineering; Wayne State Univ., Detroit, MI (United States). Div. of Engineering Technology

2010-07-01

65

A New ZVS Nonisolated Bidirectional DC-DC Converter with Minimal Auxiliary Element

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a new nonisolated bidirectional buck–boost dc–dc converter is introduced. The proposed converter can be operated under ZVS condition and fixed switching frequency regardless of the direction of power flow. To provide ZVS condition for switches a simple auxiliary circuit is used, that consists of an auxiliary inductor and a coupled winding to main inductor. Due to ZVS operation of switches, the reverse recovery problem of the body diode of the switches does not occur. Moreover, to provide soft switching any extra switch is not used in this converter, so its implementation and control is very simple. The experimental and simulation results of the proposed bidirectional converter are given to confirm the theoretical analysis.

Nasrin Asadi Madiseh

2013-01-01

66

Transformerless High Step-Up Dc-Dc Converter

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes a transformer-less high step-up DC-DC converter which acts as an interconnection between DC systems. A new step up converter proposed in the paper is designed and simulated in a simulation environment. The conventional boost converter cannot have any control over the input current at a high duty cycle. Due to which, it draws considerable amount of current from the source which can create problems for the components used in DC-DC converter. Moreover, the voltage stress across the switch comes nearly equal to output voltage. These problems can be overcome in the proposed topology discussed in the paper. The improved topology enhances important electrical parameters such as voltage gain, power loss and switch voltage stress. These improvements in the parameters are explained with the help of formulae explained in the paper. The improved topology improves the voltage stress and voltage gain. The output voltage is modified with the introduction of extra components. Due to improvement in these parameters, the proposed topology becomes an attractive feature for use with DG systems. The comparison is performed between conventional boost converter and boost converter with improved topology. The efficiency curves are plotted for simple boost converter and improved topology. The efficiency is evaluated for a wide range of duty cycle and this confirms the effectiveness of the improved topology discussed in the paper. The proposed converter design and its implementation are given with operational results. The simulation results are tested for an input voltage of 12V. The input voltage is stepped up to output voltage of 100V which can be used for various applications. The interfacing problem of DG system (PV cell arrays with grid will solve using this methodology.

Amit S. Surjagade

2014-10-01

67

A Comparison of Half Bridge & Full Bridge Isolated DC-DC Converters for Electrolysis Application

This paper presents a comparison of half bridgeand full bridge isolated, soft-switched, DC-DC converters forElectrolysis application. An electrolyser is a part of renewableenergy system which generates hydrogen from water electrolysisthat used in fuel cells. A DC-DC converter is required to coupleelectrolyser to system DC bus. The proposed DC-DC converter isrealized in both full-bridge and half-bridge topology in order toachieve zero voltage switching for the power switches and toregulate the...

Samuel Rajesh Babu, R.; Joseph Henry

2011-01-01

68

A high efficiency interleaved ZVS active clamped current fed dc-dc converter is proposed in this paper specially used for fuel cell applications. As the fuel cell output is very low we are in need of a step up dc-dc converter. Here a current fed dc-dc converter is used. Two current fed dc-dc converters are interleaved by connecting their inputs in parallel and outputs in series. With this proposed methodology input current ripples in the fuel cell stacks can be reduced and a re...

Sona P; Sheela Joseph

2014-01-01

69

Comparison of control structures for a bidirectional high-frequency dc-dc converter

A system for dc-dc power conversion based on a buck-boost converter topology is presented. It makes power flow in both directions possible. The possibility of bidirectional power flow is useful for certain applications, such as uninterruptable power supplies. Starting from a structural diagram the transfer function of the system is derived. The controller for the converter is then designed. It is made up of a simple voltage controller, a voltage controller with an inner loop current controller (cascade control) and with two kinds of state space control. The transfer functions of the different system parts are derived and dimensioning guidelines for the controller sections are presented. The closed loop behavior of the bidirectional converter for the different control structures is analyzed based on simulation using duty cycle averaging. Bodediagrams and step responses are shown.

Himmelstoss, Felix A.; Kolar, Johann W.; Zach, Franz C.

1989-08-01

70

High-Conversion-Ratio Bidirectional DC–DC Converter With Dual Coupled Inductors

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a high-conversion-ratio bidirectional DC–DC converter with dual coupled inductors is proposed. In the boost mode, two capacitors are parallel charged and series discharged by the dual coupled inductors. Thus, high step-up voltage gain can be achieved with an appropriate duty ratio. In the buck mode, two capacitors are series charged and parallel discharged by the dual coupled inductors. The bidirectional converter can have high step-down voltage gain. The stress voltage of all switches can be reduced, and the switching loss and efficiency can be improved. The operating principle and the steady-state analyses of the voltage gain are discussed. Finally, in 24V for low voltage, and 400V for high voltage, and 200W for output power, this converter simulated in MATLAB.

Omid Khezri

2014-12-01

71

Very High Frequency Half Bridge DC/DC Converter

DEFF Research Database (Denmark)

This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all components in the power stage are given. The circuit has been simulated to verify the accuracy of the presented equations and an efficiency of 89% has been shown. A prototype has been implemented with self-oscillating resonant gate drives driving the switches. The prototype has been used to drive an LED string and shows an efficiency of 85% at 29 MHz with 130 V input and 13.4 W output. The efficiency was above 82% in the range 110-150 V input with output power between 10.3 W and 16.5 W

Madsen, Mickey Pierre; Knott, Arnold

2014-01-01

72

Microcomputer control of a current source dc-dc converter

International Nuclear Information System (INIS)

A microcomputer-based time optimal control algorithm for a current source dc-dc converter is presented. The optimal control strategy for the system is shown to be bang-bang or maximum effort. The closed-loop bang-bang control was tested on a 22.4-kW energy transfer system. This system was the prototype of an inductor-converter bridge (ICB) at Argonne National Laboratory. The ICB is used for bidirectional (two-quadrant) energy transfer between two large superconducting coils. The system test setup and operation is presented in some detail. The test results of the control system are presented. The difference between the ideal and actual test results is analyzed in terms of accuracy, noise effects, quantization error, and instrumentation dynamic response. The results of this analysis are used for a systematic component specification of a microcomputer based bang-bang control system to achieve a required accuracy

73

Design & Implementation of Zero Voltage Switching Buck Converter

Zero voltage switching (ZVS) buck converter is more preferable over hard switched buck converter for low power, high frequency DC-DC conversion applications. In Zero voltage switching converter, turn on & turn off of a switch occurs at zero voltage that results in lower switching losses. In this converter soft switching is achieved by using resonant components. The optimal values of resonant components are determined by using electric functions derived from circuit configurati...

Suresh Kumar, A.; Krishna Reddy, P.

2014-01-01

74

Electrothermal model of choking-coils for the analysis of dc-dc converters

Energy Technology Data Exchange (ETDEWEB)

The paper concerns modelling the choking-coil for the needs of the electrothermal analysis of dc-dc converters. A new electrothermal model of the choking-coil is proposed. This model is dedicated for SPICE software and it takes into account nonlinearity of the dependences of the inductance on the current, selfheating and mutual thermal interactions between the core and the winding. The structure of this model is described in detail and its correctness is experimentally verified for the choking-coils with the ferrite and powder cores. Both the characteristics of the choking-coils and the buck converter with these choking-coils were considered. The satisfying agreement between the results of calculations and measurements is obtained.

Gorecki, Krzysztof, E-mail: gorecki@am.gdynia.pl [Gdynia Maritime University, Department of Marine Electronics, Morska 83, Gdynia (Poland); Detka, Kalina [Pomeranian Higher School in Gdynia, Opata Hackiego 8-10, Gdynia (Poland)

2012-09-01

75

A Novel Bidirectional DC-DC Converter With Flyback Snubber For Hybrid Electric Vehicles

Directory of Open Access Journals (Sweden)

Full Text Available Hybrid electric Vehicles combine the benefits of engine, electric motor and batteries to provide improved fueleconomy. A converter is needed in hybrid Electric Vehicle for charging and discharging of the batteries. So a charging anddischarging can be combined in one circuit topology known as bidirectional DC-DC converter. Here the output is completelyisolated from input, so an isolated bidirectional Dc-DC converter is used. In the bidirectional DC-DC converter, there occursovervoltage and overcurrent stress, which can be reduced by snubber circuits. Various technologies such as RCD, active clampand flyback snubber for bidirectional DC-DC converter are compared. The bidirectional DC-DC converter with flyback snubberis explained in detail. The simulations are carried out using Simulink/MATLAB 7.6.0 (R2009b package. The hardware is doneusing PIC16F877A, a microcontroller to generate the PWM pulses for the MOSFET switches so that harmonics in the circuit canbe reduced.

DIVYA K.NAIR

2013-06-01

76

High Power Zero-Voltage and Zero-Current Switching DC-DC Converters

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents principles and properties of the soft switching PWM DC-DC converters. The attention is focused mainly on high power applications and thus the full-bridge inverters are used in DC-DC converters. Considerations are also given to the control methods and principles of the switching and conduction losses reduction.

Jaroslav Dudrik

2005-01-01

77

Simulation and Implementation of Quasi Resonant DC-DC Converter

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: A half-bridge LLC resonant converter with a voltage doubler rectifier has a simple structure and its Zero-Voltage-Switching (ZVS capability is excellent from zero to full load condition. But conduction loss is more due to high circulating energy thus reducing the system efficiency. Moreover a variable frequency control method makes the control circuits more complicated than those using the Pulse Width Modulation (PWM control method. Thus, DC drive has lower efficiency when it operates on light loads. Approach: To improve the efficiency of the DC drive under light loads, a PWM-controlled quasi-resonant converter is proposed .It has simple control circuits and less conduction loss compared to a half-bridge LLC resonant converter under light load conditions. The proposed converter has a half-bridge LLC resonant converter along with an auxiliary circuit. The load regulation of the proposed converter can be achieved by an auxiliary circuit. Thus the proposed converter is expected to be suitable sustaining power module for the efficiency enhancement of DC drives. As the magnetizing inductance of the proposed converter is larger the circulating energy is considerably reduced under light load conditions. In this study the operational principle, design and modeling of QRC DC-DC converters for DC drives are presented. The PWM controlled quasi resonant converter is implemented using PIC microcontroller 16F184A. Results: The capacitor filter in the output is replaced by pi filter to produce DC with minimum ripple. The experimental results and simulation results are compared. This converter has the advantages like reduced number of switches, reduced transformer and filter size, reduced ripple, reduced switching losses, reduced switching stresses and increased power density. Conclusion: The experimental results closely agree with the simulation results.

N. Devarajan

2012-01-01

78

High power density dc/dc converter: Selection of converter topology

The work involved in the identification and selection of a suitable converter topology is described. Three new dc/dc converter topologies are proposed: Phase-Shifted Single Active Bridge DC/DC Converter; Single Phase Dual Active Bridges DC/DC Converter; and Three Phase Dual Active Bridges DC/DC Converter (Topology C). The salient features of these topologies are: (1) All are minimal in structure, i.e., each consists of an input and output bridge, input and output filter and a transformer, all components essential for a high power dc/dc conversion process; (2) All devices of both the bridges can operate under near zero-voltage conditions, making possible a reduction of device switching losses and hence, an increase in switching frequency; (3) All circuits operate at a constant frequency, thus simplifying the task of the magnetic and filter elements; (4) Since, the leakage inductance of the transformer is used as the main current transfer element, problems associated with the diode reverse recovery are eliminated. Also, this mode of operation allows easy paralleling of multiple modules for extending the power capacity of the system; (5) All circuits are least sensitive to parasitic impedances, infact the parasitics are efficently utilized; and (6) The soft switching transitions, result in low electromagnetic interference. A detailed analysis of each topology was carried out. Based on the analysis, the various device and component ratings for each topology operating at an optimum point, and under the given specifications, are tabulated and discussed.

Divan, Deepakraj M.

1990-01-01

79

Directory of Open Access Journals (Sweden)

Full Text Available Abstract This paper presents a scheme for implementing two different DC/DC converters in the commutation circuitry of BLDC motor drive and corresponding output characteristic in both sensored and sensorless drive. Here we have considered Buck and Boost converters in order to provide a regulated supply to the commutation circuitry. The drive circuit is a closed loop system with a PI controller, Six-Switch Voltage Source Inverter (VSI and one of the DC/DC converters among Buck and Boost. The performances with these two modes of sensored and sensorless have been studied by considering a low speed operation. Finally a comparison has been studied on the basis of characteristics of stator currents, rotor speed and electromagnetic torque. The modeling and simulation of Buck and Boost converter fed BLDC motor is done using MATLAB/SIMULINK for both sensored and sensorless drive.

Sharda Jaiswal

2014-06-01

80

Comparison Between Zvs and Zvs-Zcs Bidirectional Dc-Dc Converter Topologies

In this paper exhaustive comparative analysis has been done between a conventional ZVS converter and the ZVS-ZCS bidirectional DC-DC converters. A novel model of a bidirectional converter and its topology is introduced. The key working principles, functionality, simulation results are discussed and subsequently compared with the previous ZVS bidirectional converter system. With respect to switching losses, stresses and efficiency parameters the ZVS-ZCS bidirectional DC-DC converter is emphasi...

Subrahmanya Kumar Bhajana, V. V.; Rama Reddy, S.

2010-01-01

81

Comparison Between Zvs and Zvs-Zcs Bidirectional Dc-Dc Converter Topologies

Directory of Open Access Journals (Sweden)

Full Text Available In this paper exhaustive comparative analysis has been done between a conventional ZVS converter and the ZVS-ZCS bidirectional DC-DC converters. A novel model of a bidirectional converter and its topology is introduced. The key working principles, functionality, simulation results are discussed and subsequently compared with the previous ZVS bidirectional converter system. With respect to switching losses, stresses and efficiency parameters the ZVS-ZCS bidirectional DC-DC converter is emphasized.

V. V. Subrahmanya Kumar Bhajana

2010-07-01

82

This website from the Thayer School of Engineering at Dartmouth College features an animation of a buck converter. A buck converter is a step-down DC to DC converter. Its design is similar to the step-up boost converter, and like the boost converter it is a switched-mode power supply that uses two switches (a transistor and a diode), an inductor and a capacitor.

83

Modeling the Bi-directional DC-DC Converter for HEV's

Hybrid Electrical Vehicles-HEV!?s are the importnt ways to improve vehicle performance. The transformer isolated bi-directional DC-DC converters are the key components of the traction system in HEV!?s. This paper presents adetail mathematic model of isolated bi-directional DC-DC converter for HEV!?s. Approximate models are important mathematic methods especially for analysis and closed-loop control design converter circuits. These differential equations, which govern the converter opera...

Chongwu Wang; Xiangzhong Meng; Xiaowei Guo

2009-01-01

84

Fuzzy Predictive Control of Step-Down DC-DC Converter Based on Hybrid System Approach

In this paper, a fuzzy predictive control scheme is proposed for controlling output voltage of a step-down DC-DC converter in presence of disturbance and uncertainty. The DC-DC converter is considered as a hybrid system and modeled by Mixed Logical Dynamical modeling approach. The main objective of the paper is to design a Fuzzy Predictive Control to achieve desired voltage output without increasing complexity of the hybrid model of DC-DC converter in various conditions. A model predictive co...

Morteza Sarailoo; Zahra Rahmani; Behrooz Rezaie

2014-01-01

85

Chaos analysis and chaotic EMI suppression of DC-DC converters

Introduces chaos theory, its analytical methods and the means to apply chaos to the switching power supply design DC-DC converters are typical switching systems which have plenty of nonlinear behaviors, such as bifurcation and chaos. The nonlinear behaviors of DC-DC converters have been studied heavily over the past 20 years, yet researchers are still unsure of the practical application of bifurcations and chaos in switching converters. The electromagnetic interference (EMI), which resulted from the high rates of changes of voltage and current, has become a major design criterion in DC-DC co

Zhang, Bo

2014-01-01

86

Control of improved full-bridge three-level DC/DC converter for wind turbines in a DC grid

DEFF Research Database (Denmark)

This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency transformer in the IFBTL dc/dc converter. A modulation strategy, including two operation modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the control of the wind turbine based on the IFBTL dc/dc converter in a dc-grid system is presented. Finally, a small-scale IFBTL dc/dc converter prototype was built and tested in the laboratory, and the results verify the theoretical analysis.

Deng, Fujin; Chen, Zhe

2013-01-01

87

Optimization with System Damping Restoration for Droop Controlled DC-DC Converters

DEFF Research Database (Denmark)

The parallel operation of dc-dc converters is widely used in distribution systems and uninterruptable power supply systems. Droop control along with virtual resistance (VR) is considered a simple and reliable method for achieving wireless power sharing among converters. In order to enhance the efficiency of the conversion system, this paper implements tertiary level optimization control on the basis of hierarchical control. As the efficiency of each converter changes with output power, VRs are set as decision variables for adjusting power sharing proportion among converters. Genetic algorithm is used in searching for global efficiency optimum. However system dynamic is affected when shifting VRs. Therefore, the stability of a parallel buck converter system is analyzed to examine the influence of VR changing on system dynamics. Based on the stability analysis, a system damping secondary restoration (SDSR) is implemented to readjust the optimization results so as to ensure system stability. Simulation results are shown to demonstrate the improvement of system efficiency and effectiveness of the method.

Meng, Lexuan; Dragicevic, Tomislav

2013-01-01

88

Performance of a Voltage Step-Up/Step-Down Transformerless DC/DC Converter: Analytical Model

The authors present an analytical model for a voltage step-up/step-down DC/DC converter without transformers. The proposed topology is a combination of classic buck and boost converters in one single circuit but with differing operational principles. The converter is developed for a wind power autonomous supply system equipped with a hydrogen electrolytic tank and a fuel cell for energy stabilization. The main power source of the hydrogen-based autonomous supply system is energized by a synchronous generator operating on permanent magnets and equipped with a diode bridge. The input voltage of the converter in this case varies in the range 0-700 V, while its output DC voltage must be 540 V according to the demand of other parts of the system. To maintain the rated voltage, a special electrical load regulation is introduced. The calculations of the converter, the generator (equipped with a diode bridge) as element of the power system supply joint, and the load replaced by resistance are verified with PSIM software.

Suskis, P.; Rankis, I.

2012-01-01

89

The power converter is one of the essential elements for effective use of renewable power sources. This paper focuses on the development of a circuit simulation model for maximum power point tracking (MPPT) evaluation of solar power that involves using different buck-boost power converter topologies; including SEPIC, Zeta, and four-switch type buck-boost DC/DC converters. The circuit simulation model mainly includes three subsystems: a PV model; a buck-boost converter-based MPPT system; and ...

Jaw-Kuen Shiau; Min-Yi Lee; Yu-Chen Wei; Bo-Chih Chen

2014-01-01

90

A digitally controlled PWM/PSM dual-mode DC/DC converter

International Nuclear Information System (INIS)

A digitally controlled pulse width modulation/pulse skip modulation (PWM/PSM) dual-mode buck DC/DC converter is proposed. Its operation mode can be automatically chosen as continuous conduction mode (CCM) or discontinuous conduction mode (DCM). The converter works in PSM at DCM and in 2 MHz PWM at CCM. Switching loss is reduced at a light load by skipping cycles. Thus high conversion efficiency is realized in a wide load current. The implementations of PWM control blocks, such as the ADC, the digital pulse width modulator (DPWM) and the loop compensator, and PSM control blocks are described in detail. The parameters of the loop compensator can be programmed for different external component values and switching frequencies, which is much more flexible than its analog rivals. The chip is manufactured in 0.13 ?m CMOS technology and the chip area is 1.21 mm2. Experimental results show that the conversion efficiency is high, being 90% at 200 mA and 67% at 20 mA. Meanwhile, the measured load step response shows that the proposed dual-mode converter has good stability. (semiconductor integrated circuits)

91

Simulation and Implementation of Interleaved Boost DC-DC Converter for Fuel Cell Application

Directory of Open Access Journals (Sweden)

Full Text Available This paper deals with a boost dc-dc converter for fuel cell application. In fuel cell electric vehicles application, a high power boost dc-dc converter is adopted to adjust the output voltage, current and power of fuel cell engine to meet the vehicle requirements. One of challenge in designing a boost converter for high power application is how to handle the high current at the input side. In this paper an interleaved boost dc-dc converter is proposed for current sharing on high power application. Moreover, this converter also reduces the fuel ripple current. Performance of the interleaved boost converter is tested through simulation and experimental results. Keywords: component; Interleaved Boost Converter; Fuel Cell Electric Vehicle; high power application.

Ahmad Saudi Samosir

2011-10-01

92

Design of A Bidirectional Dc-Dc Converter For Hybrid Electric Vehicles (HEV) Using MATLAB

The design of a 60 kW bidirectional DC-DC converter is addressed in this paper. The paper also discusses the operation and role of dc-dc converter in Electric Vehicle (EV) and Hybrid Electric Vehicle (HEV). Various circuits and their analysis are done to review the operation and design of converter. Results show that at 20Hz operation converter efficiency is better when ETD49 shape is used rather than EC70. However efficiencies are greater with ferrite materials rather than iron powder.

Dharam Dutta, Souvik Ganguli

2013-01-01

93

Design of A Bidirectional Dc-Dc Converter For Hybrid Electric Vehicles (HEV Using MATLAB

Directory of Open Access Journals (Sweden)

Full Text Available The design of a 60 kW bidirectional DC-DC converter is addressed in this paper. The paper also discusses the operation and role of dc-dc converter in Electric Vehicle (EV and Hybrid Electric Vehicle (HEV. Various circuits and their analysis are done to review the operation and design of converter. Results show that at 20Hz operation converter efficiency is better when ETD49 shape is used rather than EC70. However efficiencies are greater with ferrite materials rather than iron powder.

DHARAM DUTTA, SOUVIK GANGULI

2013-07-01

94

Design of the DC-DC power stage of the capacitor charger for MAXIDISCAP power converters

This technical report presents the design of the DC-DC power stage of the capacitor charger for MAXIDISCAP power converters. The power stage is based on a half bridge series resonant converter in Discontinuous Conduction Mode (DCM). This simple and robust topology allows obtaining a current source behavior with a low switching losses power stage. The associated control stage is implemented using a commercial controller which has differenti nternal circuits that allows a high integration of the converter control system. The report presents the design and tuning criteria for the DC-DC converter, including the power stage and the control system.

Cravero, Jean-Marc

2013-01-01

95

This animation, created by faculty at Dartmouth University, is a discontinuous buck converter. The resource features other animations such as boost and discontinuous converters. They also add simple diode, bridge and half-wave rectifiers. Although simple in design, this can still be a useful resource for those interested in electrical engineering.

96

A novel active clamp dual half bridge DC/DC converter with bidirectional power flow is proposed in this paper and comparative analysis between active clamp DHB ZVZCS and ZVS-ZCS bidirectional DC-DC converter topologies is also presented. By adding active clamping circuits to both bridges, zero voltage and zero current switching are achieved to improve the performance of the bidirectional DC/DC converter. The principle of operation is analyzed and simulated. With the proposed active clamp ZVZC...

Subrahmanya Kumar Bhajana, V. V.

2012-01-01

97

Analysis of DC/DC Converter Efficiency for Energy Storage System Based on Bidirectional Fuel Cells

DEFF Research Database (Denmark)

Renewable energy sources are fluctuating depending on the availability of the energy source. For this reason, energy storage is becoming more important and bidirectional fuel cells represent an attractive technology. Fuel cells require highcurrent low-voltage dc-dc or dc-ac converters as power interface to the grid. In power electronics, the converter efficiency is characterized at fixed operating voltage for various output power. This type of characterization is not suitable for fuel cells, since as the power from the fuel cell increases, the cell voltage decreases. This paper analyses how the fuel cell I-V characteristics influences the power electronics converter efficiency and their consequence on the overall system. A loaddependent efficiency curve is presented based on experimental results from a 6 kW dc-dc converter prototype including the most suitable control strategy which maximizes the dc-dc conversion efficiency.

Pittini, Riccardo; Zhang, Zhe

2013-01-01

98

High Step Up Dc-Dc Converter For Non-Conventional Energy Source

The demand for non-isolated high step-up dc–dc converters in applications such as dc backup energy systems for UPS, photovoltaicand fuel cell systems, and hybrid electric vehicles has been gradually increasing. This project proposes a non-isolated step-up dc–dc converter with an improved switching method. The proposed converter shows zero-voltage switching turn-on of the switches in continuous conduction mode as well as reduced turnoff switching losses using resonant PWM.As a result of th...

Kuralanban, K.; Muthulakshmi, K.

2013-01-01

99

Elimination of output voltage oscillations in DC-DC converter using PWM with PI controller

Directory of Open Access Journals (Sweden)

Full Text Available In this paper the SIMULINK model of a PWM controlled DC-DC converter is modeled using switching function concept to control the speed of the DC motor. The presence of the voltage oscillation cycles due to higher switching frequency in the DC-DC converter is identified. The effect of these oscillations on the output voltage of the converter, Armature current, Developed torque and Speed of the DC motor is analyzed. In order to minimize the oscillation cycles the PI controller is proposed in the PWM controller.

Sreenivasappa Veeranna Bhupasandra

2010-01-01

100

Directory of Open Access Journals (Sweden)

Full Text Available The power electronics course is a rather challenging subject for instructors and undergraduate students pursuing Bachelor’s Degree in Electrical Engineering. To enhance teaching effectiveness and motivate self-learning capabilities of the students, this paper presents a pedagogical approach for mathematical modeling and simulation of switching mode DC-DC converters. The Buck and Boost converters are analyzed as benchmark systems to study the power converter modeling methodologies. And a comparative analysis using digital simulation from Matlab/Simulink and ATP/EMTP is presented. A summary of student survey is also presented, which shows a high level of satisfaction. The presented pedagogical approach would be useful for classroom teaching for the power electronics course and similar engineering courses.

Han Yang

2012-10-01

101

Advanced DC/DC Converters Towards Higher Volumetric Efficiencies For Space Applications

A new emphasis on planetary exploration by NASA drives the need for small, high power DC/DC converters which are functionally modular. NASA GSFC and other government space organizations are supporting technology development in the DC/DC converter area to both meet new needs and to promote more sources of supply. New technologies which enable miniaturization such as embedded passive technologies and thermal management using high thermal conductivity materials are features of the new designs. Construction of some simple DC/DC converter core circuits using embedded components was found to be successful for increasing volumetric efficiency to 37 W/inch. The embedded passives were also able to perform satisfactorily in this application in cryogenic temperatures.

Shaw, Harry; Shue, Jack; Liu, David; Wang, Bright; Plante, Jeanette

2005-01-01

102

DEFF Research Database (Denmark)

Efficiency is one of the main concerns during the design phase of switch mode power supply. Planar magnetics based on PCB windings have the potential to reduce the magnetic manufacturing cost however, one of their main drawbacks comes from their low filling factor and high stray capacitance. This paper presents an analysis of different planar windings configurations focusing on dc and ac resistances in order to achieve highly efficiency in dc-dc converters. The analysis considers different copper thicknesses form 70 ?m up to 1500 ?m (extreme copper PCB) taking into account manufacturing complexity and challenges. The analysis is focused on a high current inductor for a dc-dc converter for fuel cell applications and it is based on FEM simulations. Analysis and results are verified on a 6 kW dc-dc isolated full bridge boost converter prototype based on fully planar magnetics achieving a peak efficiency of 97.8%.

Pittini, Riccardo; Zhang, Zhe

2014-01-01

103

Optimized photovoltaic generator-water electrolyser coupling through a controlled DC-DC converter

Energy Technology Data Exchange (ETDEWEB)

The coupling of a photovoltaic generator and an electrolyser is one of the most promising options for obtaining hydrogen from a renewable energy source. Both are well known technologies, however, since the high variability of the solar radiation, an efficient coupling still presents some challenges. Direct or through a DC-DC converter couplings are the options in isolated applications. In this work, three models, respectively, for a photovoltaic (PV) generator, a controlled DC-DC converter and a complete proton exchange membrane (PEM) electrolyser have been designed by using Matlab/Simulink. A PV-electrolyser specific algorithm to search for the optimum and safe working point for both elements is presented. Simulation results demonstrate that the use of a controlled DC-DC converter with the proposed algorithm shows better adaptability to the variable radiation conditions than the other coupling options. Therefore, it leads to a better compliance between the electrolyser and the sizing of the PV generator. (author)

Garcia-Valverde, R.; Miguel, C.; Urbina, A. [Universidad Politecnica de Cartagena, Departamento de Electronica, Tecnologia de Computadoras y Proyectos, Plaza del Hospital, 1, Cartagena, 30203 Murcia (Spain); Martinez-Bejar, R. [Universidad de Murcia, Departamento de Ingenieria de la Informacion y las Comunicaciones, Facultad de Informatica, Campus de Espinardo, 30071 Murcia (Spain)

2008-10-15

104

International Nuclear Information System (INIS)

We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders the feasible introduction of this equipment in undergraduate laboratories. (paper)

105

Experimental study of dynamic behaviors and routes to chaos in DC-DC boost converters

International Nuclear Information System (INIS)

This paper illustrates an experimental study of a current-programmed DC-DC boost converter, with the aim of investigating possible pathways through which the converter may enter chaos. In particular, based on experimental measurements, it is shown that variations of input voltage and reference current can generate periodic, subharmonic, quasi-periodic and chaotic behaviors

106

We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders…

Silva-Ortigoza, R.; Silva-Ortigoza, G.; Hernandez-Guzman, V. M.; Saldana-Gonzalez, G.; Marcelino-Aranda, M.; Marciano-Melchor, M.

2012-01-01

107

Soft switching bidirectional DC-DC converter for ultracapacitor-batteries interface

International Nuclear Information System (INIS)

In this paper a new soft switching bidirectional DC-DC converter is introduced which can be applied as the interface circuit between ultracapacitors and batteries or fuel cells. All semiconductor devices in the proposed converter are soft switched while the control circuit remains PWM. Due to achieved soft switching condition, the energy conversion through the proposed converter is highly efficient. The proposed converter is analyzed and a prototype converter is implemented. The presented experimental results confirm the theoretical analysis.

108

Three-port DC-DC converter with new integrated transformer for DC Distribution Systems

DEFF Research Database (Denmark)

A new integrated transformer for three-port dc-dc converter is proposed to overcome the power coupling effect existed in some known multiple inputs dc-dc converters. Orthogonal primary windings arrangement and in series connection of diagonal secondary Windings enables a fully power decoupling between the multiple inputs while the output power is still coupled with all inputs. The energy is accordingly allowed to deliver into the output load simultaneously or at any time-multiplexing scheme. 1-kW experimental prototypes have been built to demonstrate a well-managed power flow for photovoltaic (PV) and battery standalone system.

Ouyang, Ziwei; Andersen, Michael A. E.

2014-01-01

109

Coupled Inductor Based High Step-Up DC-DC Converter for Multi Input PV System

With the shortage of the energy and ever increasing of the oil price, research on the renewable and green energy sources, especially the solar arrays and the fuel cells, becomes more and more important. How to achieve high step-up and high efficiency DC/DC converters is the major consideration in the renewable power applications due to the low voltage of PV arrays and fuel cells. In this paper a coupled inductor dc-dc converter for photovoltaic system is proposed. The circuit configuration of...

Shiny Vikram, G.

2014-01-01

110

Analysis of RF conducted emission due to PWM and resonant DC-DC converters

Energy Technology Data Exchange (ETDEWEB)

Analysis and modeling of common mode conducted ElectroMagnetic Interference (EMI) in the Radio Frequency (RF) range (10 KHZ--30MHZ) of a ZVT (DC-DC boost Zero Voltage Transition) PWM converter and a conventional PWM (DC-DC boost) converter are compared. Noise signal measurement is carried out by means of a LISN (Line Impedance Stabilization Network). To compute the noise spectrum of LISN output in RF range, direct simulation of equivalent noise circuits is implemented as well as an analysis in the frequency domain.

Mahdavi, J. [Sharif Univ. of Technology, Tehran (Iran, Islamic Republic of). Dept. of Electrical Engineering; Shahintabe, A. [Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Dept. of Electrical Engineering; Farhadi, A. [Electric Power Research Center, Tehran (Iran, Islamic Republic of). Dept. of Electronics

1995-12-31

111

Fast control technique for high frequency (5MHz) DC/DC integrated converter

A switching frequency of 5 MHz allows the integration in a chip of a low power (10W) DC/DC converter. Although this switching frequency would make feasible a voltage mode control with 1MHz bandwidth, the parasitics and robustness don't allow such a high frequency bandwidth. This paper proposes a fast control technique that helps to optimize the dynamic response of high frequency DC/DC converter. The control proposed and analyzed in this paper is based on the peak current mode control of the o...

Viejo Frutos, Miriam Del; Alou Cervera, Pedro; Oliver Rami?rez, Jesu?s Angel; Garci?a Sua?rez, Oscar; Cobos Ma?rquez, Jose? Antonio

2010-01-01

112

Isolated Bidirectional DC–DC Converter for SuperCapacitor Applications

This paper proposes a new bidirectional DC/DC converter for supercapacitor applications. The proposed converter has a parallel structure in supercapacitor side (where voltage is low and current is high) and a series structure in the other side. This structure increases efficiency of the converter. For current sharing in the parallel side of the proposed converter, two different methods are recommended and compared in this paper: Current balancing transformer (CBT) and two...

Dehnavi, Sayed M. D.; Sen, Go?khan; Thomsen, Ole Cornelius; Andersen, Michael A. E.; Møller, Lars

2011-01-01

113

Energy Conversion Module (ECM) - DC/DC converter with integrated supercaps

Energy Technology Data Exchange (ETDEWEB)

In the light of increasing hybridization of future vehicle generations mainly those functionalities will be realized which contribute to fuel- and at the end emission-reduction. Recuperation, Start-Stop, E-steering and EDS-stabilization therefore constitute applications for which an efficient energy management has to be provided In this context ALCOA / AFL Europe GmbH developed a patent pending system solution, by which in one single unit a powerful DC/DC converter is integrated with the storage medium EDLC or Super-/Ultracap - on the one hand the restrictive packaging and on the other hand high performance requirements of the OEM can be met in a high degree. Possible issues arising from the compact integration of the supercaps such as heat dissipation and EMI are solved in a unique way - even the impacts in case of a defect cell are eliminated by a sophisticated balancing. The main performance characteristics of the current finished 1 KW solution being in test operation at various OEM are: - Output: 1 KW bidirectional - Capacity: 29,8 F / 12 Cells a 350 F - Additional fused power output - Optional output for consumers during motor start - Protection class IP 6K7 - Buck/Boost converter 2-phases - Operating frequency 125 kHz - Current control and phase monitoring realized in HW With its scaleable approach and the possibility to be integrated rapidly and cost-efficient in new carlines, the ECM just today combines the advantages of an intelligent electric power management. New prospective application-ranges - i.e. up to 5 KW for commercial vehicles and/or buses - are right now under development and clear its way for series implementation, soon. (orig.)

Ollhaeuser, Helmut [ALCOA/AFL Europe GmbH (Germany)

2008-07-01

114

Energy Technology Data Exchange (ETDEWEB)

The paper discusses DC/DC converters for integration of double layer condensers into the onboard power system. First, requirements on DC/DC converters are listed and compared on the basis of three exemplary applications. A DC/DC converter concept is developed for decoupling transient high-power loads like electric steering systems. Three different topologies are compared using a specially developed method in order to find the best solution for the given application. In order to establish adequate criteria for selecting the switching frequency and inductivities of storage throttles, the influence of the trottle power change on the switching characteristics of the MOSFETs and on certain ranges of EMP interference emissions is investigated. As methods of optimising the operation of the synchronous rectifiers, parallel connection of Schottky diodes and synchronous rectifiers as well as the variation of the shut-off dead times of synchronous rectifiers were investigated. Further, a concept for converter control was developed in consideration of the intended application and topology. Finally, selected aspects for implementation of the DC/DC converter concept are presented as well as the results of experimental investigations.

Polenov, Dieter

2010-01-15

115

A Comparison of Half Bridge & Full Bridge Isolated DC-DC Converters for Electrolysis Application

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a comparison of half bridgeand full bridge isolated, soft-switched, DC-DC converters forElectrolysis application. An electrolyser is a part of renewableenergy system which generates hydrogen from water electrolysisthat used in fuel cells. A DC-DC converter is required to coupleelectrolyser to system DC bus. The proposed DC-DC converter isrealized in both full-bridge and half-bridge topology in order toachieve zero voltage switching for the power switches and toregulate the output voltage. Switching losses are reduced by zerovoltage switching. Switching stresses are reduced by usingresonant inductor and capacitor. The proposed DC-DC converterhas advantages like high power density, low EMI, reducedswitching stresses, high circuit efficiency and stable outputvoltage. The MATLAB simulation results show that the output ofconverter is free from the ripples and regulated output voltage andthis type of converter can be used for electrolyser application .Experimental results are obtained from a MOSFET based DC-DCConverter with LC filter. The

R. Samuel Rajesh Babu

2011-09-01

116

A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters. PMID:23365536

Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

2012-01-01

117

Optimization of transistors for very high frequency dc-dc converters

This document presents a method to optimize integrated LDMOS transistors for use in very high frequency (VHF, 30-300 MHz) dc-dc converters. A transistor model valid at VHF switching frequencies is developed. Device parameters are related to layout geometry and the resulting layout vs. loss tradeoffs are illustrated. A method of finding an optimal layout for a given converter application is developed and experimentally verified in a 50 MHz converter, resulting in a 35% reduction in power loss ...

Perreault, David J.; Sagneri, Anthony D.; Anderson, David I.

2009-01-01

118

Modeling and Current Programmed Control of a Bidirectional Full Bridge DC-DC Converter

Modelling of bidirectional full bridge DC-DC converter as one of the most applicable converters has received significant attention. Mathematical modelling reduces the simulation time in comparison with detailed circuit response; moreover it is convenient for controller design purpose. Due to simple and effective methodology, average state space is the most common method among the modelling methods. In this paper a bidirectional full bridge converter is modelled by average state space and for ...

Abdolreza Rahmati; Ahmad Ayatollahi; Moghaddam, Shahab H. A.

2012-01-01

119

Planar integrated magnetics design in wide input range DC-DC converter for fuel cell application

In the most power electronics converters, the overall volume is mainly determined by the number of parts and the size of passive components. Integrated magnetics and planar magnetics techniques therefore have been an excellent option in order to reduce the count and the size of magnetic components, hereby increasing the power density of converters. A new planar integrated magnetics (PIM) technique for a phase-shift plus duty cycle controlled hybrid bi-directional DC/DC converter is pres...

Ouyang, Ziwei; Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.; Poulsen, Ole; Bjorklund, Thomas

2010-01-01

120

In most power electronics converters, the overall volume is mainly determined by the number of parts and the size of passive components. Integrated magnetics and planar magnetics techniques therefore have been an excellent option in order to reduce the counts and the size of magnetic components, hereby increasing the power density of converters. In this paper, a new planar integrated magnetics (PIM) module for a phase-shift plus duty cycle controlled hybrid bi-directional dc-dc converter is p...

Ouyang, Ziwei; Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

2011-01-01

121

A DC-DC Converter with Wide Input Voltage Range for Fuel Cell and Supercapacitor Application

This paper proposes a novel phase-shift plus duty cycle controlled hybrid bi-directional DC-DC converter based on fuel cells and supercapacitors. The described converter employs two high frequency transformers to couple the half-bridge and full-bridge circuits together in the primary side and voltage doubler circuit in secondary side. Boost type converter can limit the output ripple current of the fuel cells; hybrid full-bridge structure can change operating modes according to the differen...

Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

2009-01-01

122

A Novel PPFHB Bidirectional DC-DC Converter for Supercapacitor Application

This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase-shift modulation scheme, all the switches can realize zero-voltageswitching (ZVS) turn-on and bidirectional power flow can be controlled with phase-shift angle. The operating principles of the converter are descr...

Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

2009-01-01

123

A High Voltage-lift Efficient Isolated Full Bridge DC-DC Converter

The aim of this study is to propose a high voltage lift isolated full bridge dc-dc converter. The proposed converter consists of an isolation transformer a low turn ratio to obtain high step up voltage gain. The secondary of the transformer connected with two boosting capacitors which connects parallel when power switches switch on period and discharged in series during the switch off period. In addition full bridge converter on primary side consists of clamping diode and capacitor, leakage e...

Gopi, A.; Saravanakumar, R.

2014-01-01

124

Differential Mode EMI Filter Design for Isolated DC-DC Boost Converter

DEFF Research Database (Denmark)

A Differential Mode EMI filter for a low input voltage high-current isolated dc-dc boost converter is designed and presented in this paper. The primary side Differential Mode noise voltage is low due to the high transformer turn ratio, however, the input current is very high and since the EMI limit also does not change for such converters, it requires greatly optimized design approach for the filter including the correct sizing of the filter components. A complete analytical filter design process is carried out such a way that the Differential Mode noise voltage source in the converter is identified first. The DM noise model is then established and based on the harmonic analysis of the noise source voltage waveform, the complete Differential Mode EMI filter, including the filter resonance damping branch, is designed for a 3kW isolated dc-dc boost converter. The noise model and its theoretical analysis is verified by means of experimental results.

Makda, Ishtiyaq Ahmed; Nymand, Morten

2014-01-01

125

High-Temperature SOI/SiC-Based DC-DC Converter Suite

A complete design strategy (mechanical and electrical) for a 25Ã¢Â€Â‰W 28Ã¢Â€Â‰V/5Ã¢Â€Â‰V dc-dc converter utilizing SiC and SOI electronics is presented. The converter includes a high-temperature SOI-based PWM controller featuring 150Ã¢Â€Â‰kHz operation, a PID feedback loop, maximum duty cycle limit, complementary or symmetrical outputs, and a bootstrapped high-side gate driver. Several...

Lostetter, Alexander B.; Schupbach, Roberto M.; Jared Hornberger; Robert Shaw; Brice McPherson; Reese, Bradley A.

2008-01-01

126

PWM-BASED SLIDING MODE CONTROL OF DC-DC BOOST CONVERTER

This paper explores brief idea of the Design and simulation of DC/DC Boost Converter using Pulse Width Modulation based Sliding Mode Controller operating in Continuous Conduction Mode is discussed. The performance and properties of Sliding Mode Controller is compared with conventional controllers Proportional Integral Derivative (PID) controller and Proportional Integral (PI) controller. The derived Controller/Converter system is feasible for step up purposes, as it is exposed to significant ...

Muley, Swarada S.; Nagarale, Ravindra M.

2013-01-01

127

Impact of dielectric deterioration on the conducted EMI emissions in the DC-DC boost converter

The magnitude of emitted noise generated by DC-DC converters depends on their electrical behavior and parameters. Some of these can change during the converter life time, especially due to some deterioration process. In this paper the impact of the dielectric materials aging is presented using both circuit simulation and a digital signal processing method based on Wiener filtering. The change of the total EMI spectrum as a function of the dielectric property has been investigated. Application...

Musznicki, Piotr; Schanen, Jean-luc; Granjon, Pierre; ?uszcz, Jaros?aw

2011-01-01

128

Symmetrical multilevel converters with two quadrant DC-DC feeding

In the technology sector of power electronics and control, the multilevel converter technology is still a rather new research area, but the application possibilities in the field of power drives and energy will demand more solutions with this promising technology. In the future, more converter systems will be realized with the multilevel topology. Up to now, multilevel converters have only been used in very particular applications, mainly due to the high costs and complexity of the multilevel...

Schibli, Nikolaus

2000-01-01

129

An Experimental Simulation of a Design Three-Port DC-DC Converter

Directory of Open Access Journals (Sweden)

Full Text Available Traditional DC-DC converter topologies interface two power terminals: a source and a load. The construction of diverse and flexible power management and distribution (PMAD systems with such topologies is governed by a tight compromise between converter count, efficiency, and control complexity. The broader impact of the current research activity is the development of enhanced power converter systems suitable for a wide range of applications. Potential users of this technology include the designers of portable and stand-alone systems such as laptops, hand-held electronics, and communication repeater stations. High power topology options support the evolution of clean power technologies such as hybrid-electric vehicles (HEV’s and solar vehicles. DC-DC converter is considered as an advanced environmental issue since it is a greenhouse emission eliminator. By utilizing the advancement of these renewable energy sources, we minimize the use of fossil fuel. Thus, we will have a cleaner and pollution free environment. In this paper, a three-port DC-DC converter is designed and discussed. The converter was built and tested at the energy research laboratory at Taibah University, Al Madinah, KSA.

Samir Al Sharif

2014-09-01

130

5 kW DC/DC converter for hydrogen generation from photovoltaic sources

Energy Technology Data Exchange (ETDEWEB)

This paper covers the design of a DC-DC power converter aimed for hydrogen production from photovoltaic sources. Power conditioning for such application is usually driven by different constraints: high step-down conversion ratio is required if the input voltage of such equipment has to be compatible with photovoltaic sources that are connected to grid-connected inverters; galvanic isolation; high efficiency and low mass. Taking into account those factors, this work proposes a push-pull DC/DC converter for power levels up to 5 kW. The operation and features of the converter are presented and analyzed. Design guidelines are suggested and experimental validation is also given. (author)

Garrigos, A.; Blanes, J.M.; Carrasco, J.A.; Lizan, J.L. [Area de Tecnologia Electronica, Universidad Miguel Hernandez de Elche, Avda. de la Universidad s/n, 03202 Elche, Alicante (Spain); Beneito, R. [AIJU, Avda. de la Industria 23, 03440 Ibi, Alicante (Spain); Molina, J.A. [Grupo SITEC, Calle Cadiz 38, Poligono Industrial L' Alfac III, 03440 Ibi, Alicante (Spain)

2010-06-15

131

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Full Text Available The steady state stability and performance characteristics of dc grid in electric power system used for low power and building applications are very crucial. When one converter alone extends power to all loads, life of the system is reduced due to increase in temperature, and there is limitation for expansion of capacity. These limitations are overcome by parallel functioning of bidirectional extended dc-dc converter. In this paper design and simulation of three phase parallel bidirectional dc-dc converter is discussed. The ability and performance of the system to get ripple reduction and steady state output is verified through simulation and experimentation. The design proposed can be used in dc distribution system construction and low power applications.

M. Joly

2014-12-01

132

SUBCONTRACT REPORT: DC-DC Converter for Fuel Cell and Hybrid Vehicles

Energy Technology Data Exchange (ETDEWEB)

The goal of this project is to develop and fabricate a 5kW dc-dc converter with a baseline 14V output capability for fuel cell and hybrid vehicles. The major objectives for this dc-dc converter technology are to meet: Higher efficiency (92%); High coolant temperature,e capability (105 C); High reliability (15 Years/150,000miles); Smaller volume (5L); Lower weight (6kg); and Lower cost ($75/kW). The key technical challenge for these converters is the 105 C coolant temperatures. The power switches and magnetics must be designed to sustain these operating temperatures reliably, without a large cost/mass/volume penalty.

Marlino, Laura D [ORNL; Zhu, Lizhi [Ballard Power Systems/Siemens VDO

2007-07-01

133

High Step Up Dc-Dc Converter For Non-Conventional Energy Source

Directory of Open Access Journals (Sweden)

Full Text Available The demand for non-isolated high step-up dc–dc converters in applications such as dc backup energy systems for UPS, photovoltaicand fuel cell systems, and hybrid electric vehicles has been gradually increasing. This project proposes a non-isolated step-up dc–dc converter with an improved switching method. The proposed converter shows zero-voltage switching turn-on of the switches in continuous conduction mode as well as reduced turnoff switching losses using resonant PWM.As a result of the proposed switching method, the switching losses associated with diode reverse recovery become negligible even in the small duty cycle. The capacitance in the auxiliary circuit is significantly reduced compared to the pulse width modulation method. The duty cycle loss is further reduced resulting in increased step-up ratio.The result of the project is implemented in Simulation using MATLAB Simulink Software.

K. Kuralanban

2013-04-01

134

Novel family of quasi-Z-source DC/DC converters derived from current-fed push-pull converters

DEFF Research Database (Denmark)

This paper is devoted to the step-up quasi-Z-source dc/dc push-pull converter family. The topologies in the family are derived from the isolated boost converter family by replacing input inductors with the quasi-Z-source network. Two new topologies are proposed, analyzed and compared. Theoretical predictions are verified by means of simulations.

Chub, Andrii; Husev, Oleksandr

2014-01-01

135

Isolated Bidirectional DC–DC Converter for SuperCapacitor Applications

DEFF Research Database (Denmark)

This paper proposes a new bidirectional DC/DC converter for supercapacitor applications. The proposed converter has a parallel structure in supercapacitor side (where voltage is low and current is high) and a series structure in the other side. This structure increases efficiency of the converter. For current sharing in the parallel side of the proposed converter, two different methods are recommended and compared in this paper: Current balancing transformer (CBT) and two separate inductors (TSI). Simulation and experimental results show performance of the proposed converter.

Dehnavi, Sayed M. D.; Sen, Gökhan

2011-01-01

136

Modeling the Bi-directional DC-DC Converter for HEV's

Directory of Open Access Journals (Sweden)

Full Text Available Hybrid Electrical Vehicles-HEV!?s are the importnt ways to improve vehicle performance. The transformer isolated bi-directional DC-DC converters are the key components of the traction system in HEV!?s. This paper presents adetail mathematic model of isolated bi-directional DC-DC converter for HEV!?s. Approximate models are important mathematic methods especially for analysis and closed-loop control design converter circuits. These differential equations, which govern the converter operation, change periodically among a set of linear differential equations because of the switch effect. Basing on the time-scale the state variables was separate as fast-scale and slow-scale variables. The fast changing variable of the leakage inductor was eliminated by substitute the fast-scale variable into slow-scale variable equations, resulting in reduced order differential equations. From this set of reduced orderdifferential equations the completely averaged model of the isolated DC/DC converter was derived. The simulated results reveal that the circuit and mathematical model are consistent very well. The averaged state variables can be treated as a small component plus a DC component, so the averaged model can be separated a dynamic small signal part and a DC part. This linearized small signal model is suit for control design and analysis at a steady point that is decided by the DC component. As an example a PI controller was design basing on the linear model.

Chongwu Wang

2009-02-01

137

Directory of Open Access Journals (Sweden)

Full Text Available A novel active clamp dual half bridge DC/DC converter with bidirectional power flow is proposed in this paper and comparative analysis between active clamp DHB ZVZCS and ZVS-ZCS bidirectional DC-DC converter topologies is also presented. By adding active clamping circuits to both bridges, zero voltage and zero current switching are achieved to improve the performance of the bidirectional DC/DC converter. The principle of operation is analyzed and simulated. With the proposed active clamp ZVZCS concept, the MATLAB simulation results of the applications of the fuel cell and battery have been obtained and compared with those of ZVS-ZCS bidirectional converter. The simulation results of proposed converter is compared with the ZVS-ZCS bidirectional DC-DC converter, efficiency, switching losses are the key parameters compared.

V.V.Subrahmanya Kumar Bhajana

2012-06-01

138

Pulse Skipping Modulated DC-DC Converter Modeling and Simulation

Directory of Open Access Journals (Sweden)

Full Text Available Pulse Skipping Modulated converters havelow switching losses and are more efficient at lightloads than conventional PWM converters. A Buckconverter with Pulse Skipping Modulation controlwhereby pulses applied to the switch are blocked orreleased on output voltage crossing a predeterminedvalue is considered in this paper for applicationsinvolving sources with wide variations in voltage.Results of the study on the performance of regulatorcircuit are presented. The regulator workssatisfactorily over a wide input voltage range with goodtransient response but the ripple is found to be higher.Input current spectrum indicates a good EMIperformance but with crowding of components at lowfrequency range.

SRINIVASAN Ramamurthy

2010-10-01

139

A DC-DC Conversion Powering Scheme for the CMS Phase-1 Pixel Upgrade

The powering scheme of the CMS pixel detector will be described, and the performance of prototype DC-DC buck converters will be presented, including power efficiency, system tests with DC-DC converters and pixel modules, thermal management, reliability at low temperature, and studies of potential frequency locking betwe...

Feld, Lutz Werner; Marcel Friedrichs; Richard Hensch; Karpinski, Waclaw; Klein, Katja; Sammet, Jan Domenik; Wlochal, Michael

2012-01-01

140

Output voltage regulation of a high-efficiency high step-up DC-DC power converter

Step-up dc-dc power converters are needed in many applications. Depending on the voltage conversion ratio, one or another structure should be chosen, usually leading to efficiency vs. conversion ratio trade-offs. Recently, a new class of switchmode dc-dc power converters has been introduced into the literature. These new converters show high efficiency levels at high conversion ratios, making them attractive to applications where efficiency is a major concern. Due to the complexity of the str...

Malo Barraga?n, Shane Leonardo; Grin?o? Cubero, Robert

2007-01-01

141

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

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 high-frequency dc-dc converters where high efficiency, low volume, and low noise are of primary concern.

Orlandi, S; Buso, S; Michelis, S; Fuentes, C A; Kayal, M; Faccio, F; Spiazzi, G

2011-01-01

142

DC-DC Converter Topology Assessment for Large Scale Distributed Photovoltaic Plant Architectures

Energy Technology Data Exchange (ETDEWEB)

Distributed photovoltaic (PV) plant architectures are emerging as a replacement for the classical central inverter based systems. However, power converters of smaller ratings may have a negative impact on system efficiency, reliability and cost. Therefore, it is necessary to design converters with very high efficiency and simpler topologies in order not to offset the benefits gained by using distributed PV systems. In this paper an evaluation of the selection criteria for dc-dc converters for distributed PV systems is performed; this evaluation includes efficiency, simplicity of design, reliability and cost. Based on this evaluation, recommendations can be made as to which class of converters is best fit for this application.

Agamy, Mohammed S; Harfman-Todorovic, Maja; Elasser, Ahmed; Sabate, Juan A; Steigerwald, Robert L; Jiang, Yan; Essakiappan, Somasundaram

2011-07-01

143

A Novel ZVS Bidirectional DC-DC Converter for Fuel Cell Applications

In this paper a new bidirectional dc-dc converter for a fuel cell system is proposed that has a current tripler rectifier in its low voltage side. The converter is based on a ZVS half bridge topology with current tripler rectifier at the secondary side of transformer. The asymmetrical PWM is used in the converter to achieve ZVS of power switches and to regulate the output voltage at the desired value. The proposed converter has the advantages of high efficiency, high power density and simple ...

Salami, A.; Rezaei, E.

2013-01-01

144

A High Voltage Ratio and Low Ripple Interleaved DC-DC Converter for Fuel Cell Applications

This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM s...

Chang, Long-yi; Chao, Kuei-hsiang; Chang, Tsang-chih

2012-01-01

145

Analyzing switched circuits to design DC-DC and DC-AC converters

The purpose of this paper is to present an alternative analysis of switched circuit to design square wave generators (SWG). A SWG may be designed by using low-cost electronic components, which allows to the readers to understand how DC-DC and DC-AC converters based on the switched approach is an economic option to introduce network analysis concepts. Experimental results show that used techniques allow calculate the frequency range operation not only of the electronic components but also the ...

Sandoval-ibarra, F.; Mercado-moreno, J.; Lopez, A.; Marti?nez-rivera, R.; Alba-garci?a, T.

2007-01-01

146

Boundary Conditions of Subharmonic Oscillations in Fixed-Switching-Frequency DC-DC Converters

Design-oriented boundary conditions for subharmonic oscillations are of great interest recently. Based on a subharmonic oscillation boundary condition reported in a PhD thesis more than a decade ago, extended new boundary conditions are derived in closed forms for general switching DC-DC converters. Sampled-data and harmonic balance analyses are applied and generate equivalent results. It is shown that equivalent series resistance causes the boundary conditions for voltage/c...

Fang, Chung-chieh

2012-01-01

147

Small-signal analysis of dc-dc converters with sliding mode control

Energy Technology Data Exchange (ETDEWEB)

This paper deals with small-signal analysis of dc-dc converters with sliding mode control. A suitable small-signal model is developed which allows selection of control coefficients, analysis of parameter variation effects, characterization of the closed-loop behavior in terms of audiosusceptibility, output and input impedances, and reference to output transfer function. Unlike previous analyses, the model includes effects of the filters used to evaluate state variable errors. Simulated and experimental results demonstrate model potentialities.

Mattavelli, P.; Rossetto, L.; Spiazzi, G. [Univ. of Padova (Italy)

1997-01-01

148

High Efficiency Resonant DC/DC Converter Utilizing a Resistance Compression Network

This paper presents a new topology for a high-efficiency dc/dc resonant power converter that utilizes a resistance compression network (RCN) to provide simultaneous zero-voltage switching and near-zero-current switching across a wide range of input voltage, output voltage, and power levels. The RCN maintains desired current waveforms over a wide range of voltage operating conditions. The use of ON/OFF control in conjunction with narrowband frequency control enables high efficiency to be maint...

Inam, Wardah; Perreault, David J.; Afridi, Khurram

2013-01-01

149

Fuzzy Predictive Control of Step-Down DC-DC Converter Based on Hybrid System Approach

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a fuzzy predictive control scheme is proposed for controlling output voltage of a step-down DC-DC converter in presence of disturbance and uncertainty. The DC-DC converter is considered as a hybrid system and modeled by Mixed Logical Dynamical modeling approach. The main objective of the paper is to design a Fuzzy Predictive Control to achieve desired voltage output without increasing complexity of the hybrid model of DC-DC converter in various conditions. A model predictive control is designed based on the hybrid model and applied to the system. Although the performance of the model predictive control method is satisfactory in normal condition, it suffers from lack of robustness in presence of disturbance and uncertainty. So, to succeed in facing up to the problem a fuzzy supervisor is utilized to adjust the main predictive controller based on the measured states of the system. In this paper it is shown that the proposed fuzzy predictive control scheme has advantages such as simplicity and efficiency in normal operation and robustness in presence of disturbance and uncertainty. Through simulations effectiveness of the proposed method is shown.

Morteza Sarailoo

2014-01-01

150

Design and Implementation of Digital Current Mode Controller for DC-DC Converters

DEFF Research Database (Denmark)

In the recent decades, shortage of fossil fuels and global warming have increased the demand for renewable energy resources. Dc-dc converters are widely used in renewable energy systems, electric vehicles, and battery chargers. In practical applications, dc-dc converters are required to be regulated by a closed-loop controller. The Peak Current Mode Control (PCMC) is one of the most promising control methods for dc-dc converters. It has been known for high bandwidth (speed), and inherent current protection. Increasing the controller bandwidth decreases the output filter size and cost. Analog controllers (including PCMC) are sensitive to temperature drift, component aging and noise. Digital controllers do not have the aforementioned drawbacks of analog controllers; but they have lower bandwidth than analog controllers due to the sampling and calculation delays. Generally, analog controllers have a bandwidth of 1/10 of the switching frequency. In the current state-of-the-art, the best reported digital PCMC hascrossover frequency of 1/15 of the switching frequency. In this PhD study a novel digital PCMC with negligible delay in the inner current loop has been proposed. The proposed solution has a bandwidth of 1/10 of the switching frequency; which is an improvement of 50% compared to the best reported digital solution, also the achieved crossover frequency is nearly equal to analog controller crossover frequency. Furthermore, the proposed solution offers an adaptive compensation slope; therefore the controlled converter can maintain a high bandwidth over wide range of the operating points. The proposed digital PCMC is modeled and the stability criteria are defined. The digital PCMC is implemented in a Field-Programmable Gate Array (FPGA). The experimental results verify the modeling method and the high predicted bandwidth of the proposed controller. Additionally, the small signal model of the isolated full-bridge boost converter is obtained and the modeling method is verified by experimental results. In modeling, the Equivalent Series Resistance (ESR) of the inductor and capacitor are also included. Analyzing the obtained model reveals that the small values of capacitor and inductor ESR results in a large resonance peak of complex poles in the voltage to duty cycle transfer function. High efficiency dc-dc converters essentially have low ESR in the capacitor and the inductor. Since the complex poles are eliminated in current mode control; applying the current mode control in high efficiency dc-dc converters results in much higher controller bandwidth.

Taeed, Fazel

2014-01-01

151

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the design and implementation of high frequency switched full-bridge DC-DC converter using analog control techniques. The major aim of this paper is to provide constant DC voltage to each of the switching equipment of the telephone exchange. In general, all the telephone exchanges are having switching equipment to trace out the route or the communication path to the destination. The voltage to be fed to the switching equipment is obtained from the series connected batteries and is delivered to the DC-DC converter. The DC-DC converter consists of a ferrite transformer. The voltage from the battery is being stepped down by the ferrite transformer according to the requirement. Filters are employed to suppress the harmonics and noise contents in the output voltage. The voltage obtained from the DC-DC converter is controlled by the regulating pulse width modulator using PWM technique.

Mrs. K.Rajalakshmi#1 , Mr.S.P.Karthick

2013-04-01

152

A Protection Circuit for DC-DC Converter with Voltage Doubler

This paper proposes a method to obtain a protected voltage gain by employing a protection circuit for the voltage doubler or multiplier circuit in an isolated tyde DC-DC Converter. The entire set up consists of a phase shift converter with a protected bridge/voltage doubler rectifier on the output side. The operating frequency of the phase shift converter is 20-25kHz (depending on the requirement of the application) which is high enough to improve the efficiency. Ferrite core transformer is u...

Elangovan, D.; Gopi, A.; Saravanakumar, Dr R.

2012-01-01

153

Isolated Bidirectional Full-Bridge DC–DC Converter with a Flyback Snubber

An isolated bidirectional full-bridge dc–dc converter with high conversion ratio, high output power, and soft start-up capability is proposed in this paper. The use of a capacitor, a diode, and a flyback converter can clamp the voltage spike caused by the current difference between the current-fed inductor and leakage inductance of the isolation transformer, and can reduce the current flowing through the active switches at the current-fed side. Operational principle of the proposed converte...

Chitanya; Sowjanya, K.; Raghavendran, P.

2013-01-01

154

Modeling and Current Programmed Control of a Bidirectional Full Bridge DC-DC Converter

Directory of Open Access Journals (Sweden)

Full Text Available Modelling of bidirectional full bridge DC-DC converter as one of the most applicable converters has received significant attention. Mathematical modelling reduces the simulation time in comparison with detailed circuit response; moreover it is convenient for controller design purpose. Due to simple and effective methodology, average state space is the most common method among the modelling methods. In this paper a bidirectional full bridge converter is modelled by average state space and for each mode of operations a controller is designed. Attained mathematical model results are in a close agreement with detailed circuit simulation.

Abdolreza Rahmati

2012-05-01

155

Immediate Analysis of Periodic Steady States in Switched DC-DC Converters via SPICE

Directory of Open Access Journals (Sweden)

Full Text Available The method of immediate analysis of periodic steady states in switched DC-DC converters operating in the continuous current mode is described. The initial conditions, which correspond to the periodic steady state, are found in the first step. They are used consequently for the conventional transient analysis. A special SPICE model of the converter finds automatically these initial conditions, which are then available within the transient analysis. The method works both for the well-known behavioral models of switched converters and also for models which employ complex nonlinear SPICE models of semiconductor switches.

D. Biolek

2012-04-01

156

Well-regulated DC bus voltage is the important point to guarantee power demand fulfillment in hybrid vehicle applications. Voltage regulation can be achieved with control method that determines switching signal on DC-DC converter. This paper describes the design and small scale experiment results of bus voltage regulation control for DC-DC bidirectional converter with battery and supercapacitor as energy sources. The control system consisted of two control loops. The outer loop got DC bus v...

Muh. Zakiyullah Romdlony; Amin Amin

2012-01-01

157

High switching frequency allows the integration of low power DC/DC converters. Although a high switching frequency would make feasible a voltage mode control with 1MHz bandwidth, parasitic effects and robustness don’t allow such a high bandwidth. This paper proposes a fast control to optimize the dynamic response of high frequency DC/DC converters. The proposed control is based on the peak current mode control of the output capacitor current. The output capacitor current loop provid...

Viejo Frutos, Miriam Del; Alou Cervera, Pedro; Oliver Rami?rez, Jesu?s Angel; Garci?a Sua?rez, Oscar; Cobos Ma?rquez, Jose? Antonio

2010-01-01

158

Transformerless DC-DC Converter Using Cockcroft-Walton Voltage Multiplier to Obtain High DC Voltage

Directory of Open Access Journals (Sweden)

Full Text Available In the present scenario the use of transformer for high voltages in converter circuit reduces the overall operating efficiency due to leakage inductance and use of transformer also increases the operational cost. . Therefore the proposed system is implemented with transformer less DC-DC converter so as to obtain high DC voltage with the use of nine stage Cockcroft-Walton (CW voltage multiplier. The proposed converter operates in CCM (continuous conduction mode, so that the converter switch stress, the switching losses are reduced. The DC voltage at the input of the proposed model is low and is boosted up by boost inductor (Ls in DC-DC converter stage and performs inverter operation. The number of stages in CW-voltage multiplier circuit is applied with low input pulsating DC (AC Voltage voltage where it is getting converted to high DC output voltage. The proposed converter switches operates at two independent frequencies, modulating (fsm andalternating (fsc frequency. The fsm operates at higher frequency of the output while the fsc operates at lower frequency of the desired output voltage ripple and the output ripples can be adjusted by the switch Sc1 and Sc2. The regulation of the output voltage is achieved by controlling the Duty ratio.The simulation is carried over by the MATLABSIMULINK.

Meghana G Naik,

2014-11-01

159

An Effective High Step-Up Interleaved DC-DC Converter Photovoltaic Grid Connection System

Directory of Open Access Journals (Sweden)

Full Text Available Within the photovoltaic (PV power generation systems in the market, the ac PV module has shown obvious growth. However, a high voltage gain converter is concentrate for the module’s grid connection with dc-ac inverter. This paper proposed a converter that employs a floating active switch to isolate energy from the PV panel when the ac module is OFF; this particular design protects installers and users from electrical hazards. Without extreme duty ratios and numerous turns-ratio of a coupled inductor, this converter achieves a high step-up voltage-conversion ratio; the leakage inductor energy of the coupled inductor is efficiently recycled to the load. These features explain about module’s high-efficiency performance. The detailed operating principles and steady-state analyses of continuous mode is described. A 15 volts produces from photovoltaic which is connects to high step-up dc-dc converter to produces output voltage of 170 volts. The novel proposed system is “an effective high step up interleaved dc-dc converter photovoltaic grid connection system”. In this configuration consists of PV array, high step-up interleaved dc-dc converter and three-phase inverter with grid connected system. In this system, the THD value per phase voltage of three phase inverter output without filter is 1.74% with grid connection system. In this same configuration with 2nd order filter connected of three phase inverter output, the THD value reduced to 0.08%. The results are shown in Matlab/simulink 2009a.

G. Lakpathi,

2013-09-01

160

Modeling and Simulation of Sensorless Speed Control of a Buck Converter Controlled Dc Motor

Directory of Open Access Journals (Sweden)

Full Text Available This paper investigate a sensorless speed control of a separately excited dc motor fed from a buck type dc-dc converter. The control system is designed in digital technique by using a two dimension look-up table. The performance of the drive system was evaluated by digital simulation using Simulink toolbox of Matlab.

Tagreed M. Ali

2010-01-01

161

A bidirectional DC-DC converter for supercapacitor-based energy storage systems in advanced electric vehicles is proposed in this letter. This converter consists of a half-bridge and current-fed push-pull circuit linked with a high frequency transformer, which is well applicable to the low voltage/high current charge and discharge of the supercapacitor. The experimental results of the prototype system prove the effective properties of the proposed topology in terms of a low device-conduction loss and a low switching surge.

Mishima, Tomokazu; Hiraki, Eiji; Yamamoto, Kouji; Tanaka, Toshihiko

162

Digital simulation of closed loop control of bi-directional dc - dc converter

This paper presents a closed loop control of isolated boost full bridge dc-dc converter for used in Medium and High power application. Zero voltage switching is applied in all switches. The dc inputvoltage is stepped up by using a boost converter. It is inverted using a fullbridge inverter. The transformer is used to produce a higher voltage in secondary voltage side The a.c. voltage is convertedinto d.c. voltage with the help of rectifier. The open loop model there is no possiblity of mainta...

S.A. Elankurisil,; Dr.D.Sivakumar,; Dash, Dr S. S.

2011-01-01

163

Interleaved Self-Oscillating Class E Derived Resonant DC/DC Converters

DEFF Research Database (Denmark)

A new method for achieving self-oscillating, self-interleaved operation of class E derived resonant DC/DC converters is presented. The proposed method is suitable for operation at frequencies in the Very High Frequency (VHF) band. Interleaved and self-oscillating modes of operation are achieved at the same time with very small number of additional passive components in the interconnection network. To verify the proposed technique, a 110MHz prototype resonant boost converter was designed; experimental results and comparison with SPICE simulation are presented. Peak measured efficiency was 89% in continuous operation.

Kovacevic, Milovan; Knott, Arnold

2012-01-01

164

Method for Controlling a Multilevel Cascade BTB System Using Bidirectional Isolated DC/DC Converters

This paper discusses a 6.6-kV next-generation BTB system in which bidirectional isolated dc/dc converters are combined with modular multilevel cascade converters. The system consists of N converter cells cascaded in each phase at both front ends. Each converter cell consists of a bidirectional isolated dc/dc converter and two voltage-source H-bridge PWM converters. This circuit configuration can be adopted to significantly reduce harmonic voltages and currents because the voltage steps are extremely low. In a conventional power conversion system, bulky line-frequency transformers are employed. On the other hand, in the present system, light and compact high-frequency transformers are used for providing galvanic isolation. Thus, the overall physical size and weight are reduced. The authors design, construct, and test a single-phase 120-V, 3.3-kW downscaled model with N=3, in order to verify the feasibility and effectiveness. The downscaled model helps to develop an operable 6.6-kV system with focus on control and performance.

Kitada, Ryohei; Akagi, Hirofumi

165

A method and an apparatus is provided for efficiently controlling the power output of a solar cell array string or a plurality of solar cell array strings to achieve a maximum amount of output power from the strings under varying conditions of use. Maximum power output from a solar array string is achieved through control of a pulse width modulated DC/DC buck converter which transfers power from a solar array to a load or battery bus. The input voltage from the solar array to the converter is controlled by a pulse width modulation duty cycle, which in turn is controlled by a differential signal controller. By periodically adjusting the control voltage up or down by a small amount and comparing the power on the load or bus with that generated at different voltage values a maximum power output voltage may be obtained. The system is totally modular and additional solar array strings may be added to the system simply by adding converter boards to the system and changing some constants in the controller's control routines.

Frederick, Martin E. (inventor); Jermakian, Joel (inventor)

1991-01-01

166

Control and Analysis of Synchronous Rectifier Buck Converter for ZVS in Light Load Condition

Directory of Open Access Journals (Sweden)

Full Text Available This paper aims to improve the efficiency of a dc-dc buck converter. It enables a synchronous rectifier buck converter to realize zero voltage switching in light load condition. The replacement of output rectifier diode by MOSFET can minimize conduction losses and increase the efficiency of the circuit. The control technique introduced in this paper enables a SR buck converter to carry out ZVS in light load condition to increase efficiency. No extra auxiliary switches or RLC passive components are required. It is of low cost and easy to control.

NIMMY JOSEPH

2013-06-01

167

Bidirectional buck boost converter

A bidirectional buck boost converter and method of operating the same allows regulation of power flow between first and second voltage sources in which the voltage level at each source is subject to change and power flow is independent of relative voltage levels. In one embodiment, the converter is designed for hard switching while another embodiment implements soft switching of the switching devices. In both embodiments, first and second switching devices are serially coupled between a relatively positive terminal and a relatively negative terminal of a first voltage source with third and fourth switching devices serially coupled between a relatively positive terminal and a relatively negative terminal of a second voltage source. A free-wheeling diode is coupled, respectively, in parallel opposition with respective ones of the switching devices. An inductor is coupled between a junction of the first and second switching devices and a junction of the third and fourth switching devices. Gating pulses supplied by a gating circuit selectively enable operation of the switching devices for transferring power between the voltage sources. In the second embodiment, each switching device is shunted by a capacitor and the switching devices are operated when voltage across the device is substantially zero.

Esser, Albert Andreas Maria (Niskayuna, NY)

1998-03-31

168

Light weight, high power, high voltage dc/dc converter technologies

Power-conditioning weight reductions by orders of magnitude will be required to enable the megawatt-power-level space systems envisioned by the Strategic Defense Initiative, the Air Force, and NASA. An interagency program has been initiated to develop an 0.1-kg/kW dc/dc converter technology base for these future space applications. Three contractors are in the first phase of a competitive program to develop a megawatt dc/dc converter. Researchers at NASA Lewis Research Center are investigating innovative converter topology control. Three different converter subsystems based on square wave, resonant, and super-resonant topologies are being designed. The components required for the converter designs cover a wide array of technologies. Two different switches, one semiconductor and the other gas, are under development. Issues related to thermal management and material reliability for inductors, transformers, and capacitors are being investigated in order to maximize power density. A brief description of each of the concepts proposed to meet the goals of this program is presented.

Kraus, Robert; Myers, Ira; Baumann, Eric

1990-01-01

169

A Novel ZVS Bidirectional DC-DC Converter for Fuel Cell Applications

Directory of Open Access Journals (Sweden)

Full Text Available In this paper a new bidirectional dc-dc converter for a fuel cell system is proposed that has a current tripler rectifier in its low voltage side. The converter is based on a ZVS half bridge topology with current tripler rectifier at the secondary side of transformer. The asymmetrical PWM is used in the converter to achieve ZVS of power switches and to regulate the output voltage at the desired value. The proposed converter has the advantages of high efficiency, high power density and simple circuit configuration. The operation principle and system analysis are described and discussed. Finally, the simulation results for the proposed converter are provided to verify the theoretical analysis.

A. Salami

2013-01-01

170

A Novel ZVS Bidirectional DC-DC Converter for Fuel Cell Applications

Directory of Open Access Journals (Sweden)

Full Text Available In this paper a new bidirectional dc-dc converter for a fuel cell system is proposed that has a current tripler rectifier in its low voltage side. The converter is based on a ZVS half bridge topology with current tripler rectifier at the secondary side of transformer. The asymmetrical PWM is used in the converter to achieve ZVS of power switches and to regulate the output voltage at the desired value. The proposed converter has the advantages of high efficiency, high power density and simple circuit configuration. The operation principle and system analysis are described and discussed. Finally, the simulation results for the proposed converter are provided to verify the theoretical analysis.

A. Salami

2013-05-01

171

Digital simulation of closed loop control of bi-directional dc - dc converter

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a closed loop control of isolated boost full bridge dc-dc converter for used in Medium and High power application. Zero voltage switching is applied in all switches. The dc inputvoltage is stepped up by using a boost converter. It is inverted using a fullbridge inverter. The transformer is used to produce a higher voltage in secondary voltage side The a.c. voltage is convertedinto d.c. voltage with the help of rectifier. The open loop model there is no possiblity of maintain a constant voltage with variation of input voltage. In closed loop system is maintain a constant voltage is applied with various value of input voltage. Matlab 7.3 version is used for simulating the open loop and closed loop full bridge dc – dc converter are verified. Isolated boost converter can operate at an input voltage of 24V and the output voltage 200-260 V and average efficiency of 89% at 55khz switching frequency.

S.A. Elankurisil,

2011-02-01

172

This paper analyzes and simulates the Li-ion battery charging process for a solar powered battery management system. The battery is charged using a non-inverting synchronous buck-boost DC/DC power converter. The system operates in buck, buck-boost, or boost mode, according to the supply voltage conditions from the solar panels. Rapid changes in atmospheric conditions or sunlight incident angle cause supply voltage variations. This study develops an electrochemical-based equivalent circuit mod...

Chien-Wei Ma; Jaw-Kuen Shiau

2013-01-01

173

A Cascaded Quasi Z-Source Scheme Step up DC-DC Converter Using ANN Based Control.

Directory of Open Access Journals (Sweden)

Full Text Available Modern renewable generation systems need smart and integrated power converters ensure for high efficiency of power conversion .This project intends to the Artificial Neural Network (ANN based control step up DC-DC converter family with a cascaded Quasi Z-source network (qZS-scheme.The cascaded (two-stage qZS- network could be derived by the adding of one diode, one inductor, and two capacitors to the traditional single stage quasi-Z-source inverter (qZSI. The proposed cascaded qZSI giving as same all the advantages of the traditional solution (voltage boost and buck functions in a single stage, continuous input current ,and improved reliability.As compared to the conventional qZSI, the proposed solution reduces the shoot-through duty cycle at the same voltage boost factor ,and without adding additional switches. The ANN based controller ensuring the better result compare to the conventional PI controller .The two-stage qZSI in the shoot-through and non-shoot-through operating modes are described. The proposed and conventional closed loop results are compared.

R.Praburaja

2013-06-01

174

New solar cell power supply system using a boost type bidirectional dc-dc converter

New solar cell power supply system is presented, in which the boost type bidirectional dc-dc converter and the simple control circuit with a small monitor solar cell are employed to track the maximum power point of the solar array. It is confirmed by the experiment that the new system has the sufficiently precise tracking operation performance and the satisfactorily high power efficiency. Also, a comparison of the power efficiencies is made with theoretically as well as experimentally on the new and the conventional solar cell power supply systems. As a result, it is revealed that the new system is superior to the conventional one in the power efficiency.

Matsuo, H.; Kurokawa, F.

175

Analysis and design of PPFHB bidirectional DC-DC converter with coupled inductors

In this paper, a novel push-pull-forward half-bridge (PPFHB) bi-directional DC-DC converter with coupled inductors is proposed. All switches can operate under zero-voltage-switching (ZVS). The operation principle with phase-shift modulation scheme, characteristics of coupled inductors, the steady state relationship and small-signal model are analyzed. The voltage controller based on the small-signal model in z-domain is designed. A 500W prototype controlled by TMS320F2808 DSP is implemented a...

Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

2009-01-01

176

Analysis and design of PPFHB bidirectional DC-DC converter with coupled inductors

DEFF Research Database (Denmark)

In this paper, a novel push-pull-forward half-bridge (PPFHB) bi-directional DC-DC converter with coupled inductors is proposed. All switches can operate under zero-voltage-switching (ZVS). The operation principle with phase-shift modulation scheme, characteristics of coupled inductors, the steady state relationship and small-signal model are analyzed. The voltage controller based on the small-signal model in z-domain is designed. A 500W prototype controlled by TMS320F2808 DSP is implemented and tested. Experimental results show the validity of the analysis and design.

Zhang, Zhe; Thomsen, Ole Cornelius

2009-01-01

177

The design of RF power supply using DC-DC converter

International Nuclear Information System (INIS)

This paper proposes the design concept of a new RF power supply using DC-DC converters without large filter capacitors and crowbar circuits. The RF power supply is designed to get quite smoothness, fast turn off and on output characteristics. These characteristics are cleared with system simulation and a small experimental model. A 2MW (-100kV, 20A) power supply design is introduced and a view point of realization and total system efficiency are also discussed. 2 refs., 13 figs

178

COMPARISON OF PID TUNING TECHNIQUES FOR CLOSED LOOP CONTROLLER OF DC-DC BOOST CONVERTER

Directory of Open Access Journals (Sweden)

Full Text Available The capability of PID controller to withstand practical industrial problems has led to its inclusive acceptance in industries and academics. It has been observed that PID controller tuning is quite difficult by classical methods using graphs and mathematical analysis. In this paper, PID theory is briefly summarized and some standard tuning methods are discussed using MATLAB. Accordingly compensator transfer function is derived by different methods and compared based on the steady state response and system characteristics. This effort inspects which method is best for conventional DC-DC boost converter.

Apekshit Bhowate

2015-02-01

179

Comparison of two different high performance mixed signal controllers for DC/DC converters

DEFF Research Database (Denmark)

This paper describes how mixed signal controllers combining a cheap microcontroller with a simple analogue circuit can offer high performance digital control for DC/DC converters. Mixed signal controllers have the same versatility and performance as DSP based controllers. It is important to have an engineer experienced in microcontroller programming write the software algorithms to achieve optimal performance. Two mixed signal controller designs based on the same 8-bit microcontroller are compared both theoretically and experimentally. A 16-bit PID compensator with a sampling frequency of 200 kHz implemented in the 16 MIPS, 8-bit ATTiny26 microcontroller is demonstrated.

Jakobsen, Lars TØnnes; Andersen, Michael Andreas E.

2006-01-01

180

Four Quadrants Integrated Transformers for Dual-input Isolated DC-DC Converters

DEFF Research Database (Denmark)

A common limitation of power coupling effect in some known multiple-input dc-dc converters has been addressed in many literatures. In order to overcome this limitation, a new concept for decoupling the primary windings in the integrated multiple-winding transformers based on 3-dimensional (3D) space orthogonal flux is proposed in this letter. And thus a new geometry core and relative winding arrangements are proposed in accordance with the orthogonal flux decoupling technology. Due to the four secondary windings are arranged in a quadratic pattern at the base core plate with the two perpendicular primary windings, a name of “four quadrants integrated transformers” (FQIT) is therefore given to the proposed construction. Since the two primary windings are uncoupled, the FQIT allows the two input power stages to transfer the energy into the output load simultaneously or at any timemultiplexing scheme, which can optimize the utilization of input sources, simplify the system structure and reduce the overall cost, so they are attractive for the hybrid renewable power system. Section IV initiates a discussion for the advantages of the FQIT. In order to verify the feasibility of the FQIT in multiple-input converter, a dualinput isolated boost dc-dc converter with the FQIT is designed and tested. The results have excellently demonstrated that the two input power stages can be operated independently and the correctness of all the analysis in the letter.

Ouyang, Ziwei; Zhang, Zhe

2012-01-01

181

A VHF Class E DC-DC Converter with Self-Oscillating Gate Driver

DEFF Research Database (Denmark)

This paper describes the analysis and design of a DC-DC converter topology which is operational at frequencies in the Very High Frequency (VHF) band ranging from 30 MHz ? 300 MHz. The presented topology, which consists of a class E inverter, class E rectifier, and self-oscillating gate driver, is inherently resonant, and switching losses are greatly reduced by ensuring Zero Voltage Switching (ZVS) of the power semiconductor devices. A design method to ensure ZVS operation when combining the inverter, rectifier, and gate driver is provided. Several parasitic effects and their influence on converter operation are discussed, and measurement results of a 100 MHz prototype converter are presented and evaluated. The designed prototype converter verifies the described topology.

Andersen, Toke Meyer; Christensen, SØren K.

2011-01-01

182

A DC-DC Converter with Wide Input Voltage Range for Fuel Cell and Supercapacitor Application

DEFF Research Database (Denmark)

This paper proposes a novel phase-shift plus duty cycle controlled hybrid bi-directional DC-DC converter based on fuel cells and supercapacitors. The described converter employs two high frequency transformers to couple the half-bridge and full-bridge circuits together in the primary side and voltage doubler circuit in secondary side. Boost type converter can limit the output ripple current of the fuel cells; hybrid full-bridge structure can change operating modes according to the different input voltage; phase-shift with duty cycle control scheme is utilized to control the bidirectional power flow flexibly. All the switches can turn on under zero-voltage-switching condition (ZVS). The operating principles of the converter are described in details, and the experimental results based on the prototype controlled by DSP are presented to verify the validity of the analysis and design.

Zhang, Zhe; Thomsen, Ole Cornelius

2009-01-01

183

A Two-stage DC-DC Converter for the Fuel Cell-Supercapacitor Hybrid System

DEFF Research Database (Denmark)

A wide input range multi-stage converter is proposed with the fuel cells and supercapacitors as a hybrid system. The front-end two-phase boost converter is used to optimize the output power and to reduce the current ripple of fuel cells. The supercapacitor power module is connected by push-pull-forward half bridge (PPFHB) converter with coupled inductors in the second stage to handle the slow transient response of the fuel cells and realize the bidirectional power flow control. Moreover, this cascaded structure simplifies the power management. The control strategy for the whole system is analyzed and designed. A 1kW prototype controlled by TMS320F2808 DSP is built in the lab. Simulation and experimental results confirm the feasibility of the proposed two stage dc-dc converter system.

Zhang, Zhe; Thomsen, Ole Cornelius

2009-01-01

184

Non-Inverting Buck-Boost Converter for Fuel Cell Applications

Fuel cell DC/DC converters often have to be able to both step-up and step-down the input voltage, and provide a high efficiency in the whole range of output power. Conventional negative output buck-boost and non-inverting buck-boost converters provide both step-up and step-down characteristics. In this paper the non-inverting buck-boost with either diodes or synchronous rectifiers is investigated for fuel cell applications. Most of previous research does not consider the parasitic in the e...

Schaltz, Erik; Rasmussen, Peter Omand; Khaligh, Alireza

2008-01-01

185

A new DC-DC converter technology suitable to support grid connection of wave power energy converter

Since 2002, the department of electricity at Uppsala university has pushed the Lysekil project. The project has a number of wave energy converters installed in the sea southwest of Lysekil. The purpose of this work is to design, build and test a DC-DC converter, which will later be used as a necessary part of the grid connection of a wave energy converter. Since a wave energy converter does not generate electricity at a constant frequency, it is not possible to use a gearbox. Instead, power i...

Back, Erik

2012-01-01

186

DEFF Research Database (Denmark)

This paper presents driving circuit for a recently invented dielectric electro active polymer (DEAP) incremental actuator. The basic operation of such an actuator is bioinspired from the movement of an inchworm. The actuator consists of three electrically isolated, and mechanically connected capacitive sub-actuators. It needs to be driven by three high voltage (~2.5 kV) DC-DC converters, to achieve the linear incremental motion. The topology used for this application is a bi-directional flyback DC-DC converter. The control of the incremental actuator involves, implementation of digital controller used for controlling charge and discharge sequences of the individual sub-actuators, and monitoring and adjustment of the output voltages of three high voltage DC-DC converters to provide over-voltage protection capability. Three power stages of the proposed converter were experimentally tested. The experimental results and efficiency measurements are shown.

Thummala, Prasanth; Zhang, Zhe

2013-01-01

187

Analyzing switched circuits to design DC-DC and DC-AC converters

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish El propósito de este artículo es presentar un análisis alternativo de circuitos conmutados para diseñar generadores de onda cuadrada, SWG (del Inglés Square Wave Generator). Un SWG puede ser diseñado usando componentes electrónicos de bajo costo, lo cual permite al lector comprender como los convert [...] idores DC-DC y DC-AC basados en la aproximación conmutada es una opción económica para introducir conceptos del análisis de redes. Los resultados experimentales muestran que las técnicas usadas permiten calcular el rango de operación no solo de los componentes electrónicos sino también del efecto que el valor de la fuente de alimentación tiene en el desempeño de los generadores. Abstract in english The purpose of this paper is to present an alternative analysis of switched circuit to design square wave generators (SWG). A SWG may be designed by using low-cost electronic components, which allows to the readers to understand how DC-DC and DC-AC converters based on the switched approach is an eco [...] nomic option to introduce network analysis concepts. Experimental results show that used techniques allow calculate the frequency range operation not only of the electronic components but also the effect of the power supply value on the generators' performance.

F., Sandoval-Ibarra; J., Mercado-Moreno; A., Lopez; R., Martínez-Rivera; T., Alba-García.

2007-06-01

188

Time delay control for fuel cells with bidirectional DC/DC converter and battery

Energy Technology Data Exchange (ETDEWEB)

Transient behavior is a key property in the vehicular application of proton exchange membrane (PEM) fuel cells. A better control technology is constructed to increase the transient performance of PEM fuel cells. A steady-state isothermal analytical fuel cell model is constructed to analyze mass transfer and water transport in the membrane. To prevent the starvation of air in the PEM fuel cell, time delay control is used to regulate the optimum stoichiometric amount of oxygen, although dynamic fluctuations exist in the PEM fuel cell power. A bidirectional DC/DC converter connects the battery to the DC link to manage the power distribution between the fuel cell and the battery. Dynamic evolution control (DEC) allows for adequate pulse-width modulation (PWM) control of the bidirectional DC/DC converter with fast response. Matlab/Simulink/Simpower simulation is performed to validate the proposed methodology, increase the transient performance of the PEM fuel cell system and satisfy the requirement of energy management. (author)

Kim, Y.B. [Mechanical Engineering Department, Chonnam National University, Gwangju (Korea); Kang, S.J. [Mechatronics Engineering Department, Korea Polytechnic College V, Gwangju (Korea)

2010-08-15

189

Design of a total-dose radiation hardened monolithic CMOS DC-DC boost converter

International Nuclear Information System (INIS)

This paper presents the design and implementation of a monolithic CMOS DC-DC boost converter that is hardened for total dose radiation. In order to improve its radiation tolerant abilities, circuit-level and device-level RHBD (radiation-hardening by design) techniques were employed. Adaptive slope compensation was used to improve the inherent instability. The H-gate MOS transistors, annular gate MOS transistors and guard rings were applied to reduce the impact of total ionizing dose. A boost converter was fabricated by a standard commercial 0.35 ?m CMOS process. The hardened design converter can work properly in a wide range of total dose radiation environments, with increasing total dose radiation. The efficiency is not as strongly affected by the total dose radiation and so does the leakage performance. (semiconductor integrated circuits)

190

A high voltage gain quasi Z-source isolated DC/DC converter

DEFF Research Database (Denmark)

A compact quasi-Z-source DC/DC converter is presented with high voltage gain, isolated output, and improved efficiency. The improvements in size and performance were achieved by using a square wave inverter with only two output switches driving an isolating transformer in push-pull mode, followed by a voltage doubling output rectifier. The converter is well-suited to applications requiring a high voltage gain, especially renewable energy sources such as photovoltaic and fuel-cell power supplies. To demonstrate the converter's performance a prototype designed to output 400 V at 500 W was constructed and tested. The efficiency at full load varied from 89.0% to 97.4% as the input voltage changed from 44 V to 82 V.

Siwakoti, Yam P.; Blaabjerg, Frede

2014-01-01

191

Systematic design approach of fuzzy PID stabilizer for DC-DC converters

International Nuclear Information System (INIS)

DC-DC converters process electrical energy by switching between a fixed number of configurations. The objective of controlling these systems is to provide better performances, ensure closed loop stability and guarantee a simple predictable behaviour. Based on a converter averaged model, we propose, in this paper, a systematic design approach of a fuzzy PID. The choice of controller parameters stands on the whole system stability requirements. Extension of the obtained asymptotic stability to structural stability is presented to show that the developed controller ensures also a simple and predictable behaviour of the converter. Finally, we illustrate the efficiency of the proposed fuzzy PID design approach through simulations in voltage mode as well as in current mode control

192

A High Voltage-lift Efficient Isolated Full Bridge DC-DC Converter

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study is to propose a high voltage lift isolated full bridge dc-dc converter. The proposed converter consists of an isolation transformer a low turn ratio to obtain high step up voltage gain. The secondary of the transformer connected with two boosting capacitors which connects parallel when power switches switch on period and discharged in series during the switch off period. In addition full bridge converter on primary side consists of clamping diode and capacitor, leakage energy is recycled there by improving conversion efficiency. The proposed circuits simulated using PSIM software form input voltage of 48V, an output of 410 V obtained. These results and operations experimented and validated by implementing in hardware model at 20/40 Vdc, 20 Watts.

A. Gopi

2014-05-01

193

A Novel PPFHB Bidirectional DC-DC Converter for Supercapacitor Application

DEFF Research Database (Denmark)

This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase-shift modulation scheme, all the switches can realize zero-voltageswitching (ZVS) turn-on and bidirectional power flow can be controlled with phase-shift angle. The operating principles of the converter are described in detail, ZVS conditions are discussed, parameters are designed, and the experimental results based on the prototype controlled by DSP are presented to verify the validity of the analysis and design.

Zhang, Zhe; Thomsen, Ole Cornelius

2009-01-01

194

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish El control de convertidores DC/DC, topologías utilizadas ampliamente en la reducción activa de contenido armónico para equipo monofásico no lineal de baja potencia, plantea grandes retos de diseño debido a lo complejo del modelo matemático y su característica dinámica altamente no lineal. Técnicas d [...] e inteligencia artificial como las redes neuronales, suponen grandes mejoras en el diseño y desempeño final, dada su capacidad de aprender dinámicas complejas y generalizar su comportamiento. La motivación de este trabajo fue la de plantear (y posteriormente evaluar la respuesta dinámica) un lazo de control directo con redes neuronales, que permitiera adicionalmente eliminar elementos de prueba y error en su diseño. Se propone un control directo basado en red neuronal artificial, cuyo diseño se realizó de forma óptima utilizando modelos de búsqueda bioinspirada, esto para optimizar simultáneamente dos aspectos diferentes pero fundamentales de la red: la arquitectura y los pesos de las conexiones. El control es aplicado a un convertidor boost. Los resultados obtenidos permiten observar el desempeño dinámico del esquema, para el cual los tiempos de respuesta y los delta de voltaje en la salida permiten concluir que los criterios seleccionados para el diseño del control son apropiados y representan un aporte en el desarrollo de aplicaciones de control de sistemas conmutados DC/DC. Abstract in english Controlling DC/DC converters (topologies widely used in the active reduction of harmonic content for singlephase nonlinear low power equipment) raises great design challenges due to the mathematical model's complexity and its highly nonlinear dynamic characteristics. Artificial intelligence techniqu [...] es, such as neuronal networks, suppose great improvements in design and final performance, given their capacity for learning complex dynamics and generalising their behaviour. This work was aimed at proposing (and evaluating dynamic response later on) direct control link with neuronal networks which also allowed eliminating test elements and error in its design. Artificial neuronal networkbased direct control was designed as well as possible using bioinspired search models. This simultaneously optimised two different but fundamental aspects of the network: architecture and the weight of the connections. The control was applied to a boost converter. The results led to observing the scheme's dynamic performance; response time and exit voltage delta led to concluding that the criteria selected for designing the control were appropriate and represented a contribution towards developing control applications of DC/DC switchmode systems.

Fredy Hernán, Martínez Sarmiento; Mariela, Castiblanco Ortíz.

2009-12-01

195

Directory of Open Access Journals (Sweden)

Full Text Available The design of a bidirectional dc-dc power converter specifically for a distributed energy application is presented. The existing two different DC voltage battery bank of the distributed generation needs to interlink each other using a bi-directional dc-dc converter in order to minimize the unbalance of the output load currents of the three inverters connected to electric grid system. Through this connection, a current can flow from one system to another or vice versa depending on which systems need the current most. Thus, unbalanced currents of the grid line have been minimized and the reliability and performance of the DER grid connected system has been increased. A detailed mathematical analysis of the converter under steady state and transient condition are presented. Mathematical models for boost and buck modes are being derived and the simulink model is constructed in order to simulate the system. Moreover, the model has been validated on the actual operation of the converter, showing that the simulated results in Matlab Simulink are consistent with the experimental ones.

Ambrosio B. Cultura II

2012-09-01

196

A Novel Half-Bridge Asymmetrical ZCS-PWM DC-DC Converter with High Frequency-Link

A novel zero current soft-switching (ZCS)-PWM cell-assisted half-bridge DC-DC converter topology with a high frequency link is proposed in this paper. The newly-proposed DC-DC converter consists of a PWM-controlled single-ended half-bridge high frequency (HF) inverter and a current doubler rectifier linked with a HF transformer. In order to attain the wide range of ZCS-PWM operation in the primary-side HF inverter, an active edge resonant snubber cell composed by a switched capacitor and a lossless inductor is adopted in the half-bridge leg, providing ZCS commutation for a wide range of output power. The operation characteristics of the DC-DC converter proposed here are described, and its feasibility data is demonstrated and evaluated with simulation and experimental results.

Mishima, Tomokazu; Hiraki, Eiji; Tanaka, Toshihiko; Nakaoka, Mutsuo

197

A novel technique for reducing the ripple current in a DC link capacitor by harmonic control of the DC/DC converter and PWM inverter is proposed in this paper. The proposed technique synchronizes the switching frequencies of the PWM inverter and the DC/DC converter and optimizes the phase difference of the carrier waveforms between them. The effectiveness of our technique is shown by simulation and an experiment conducted with a 10-kW PM motor drive system. In comparison to the conventional technique, the proposed technique reduces the ripple current in the DC link capacitor by 20-40% in a PWM inverter drive system with a DC/DC converter.

Okuda, Tatsuya; Urakabe, Takahiro; Tsunoda, Yoshikazu; Kikunaga, Toshiyuki; Iwata, Akihiko

198

Analyzing switched circuits to design DC-DC and DC-AC converters

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this paper is to present an alternative analysis of switched circuit to design square wave generators (SWG. A SWG may be designed by using low-cost electronic components, which allows to the readers to understand how DC-DC and DC-AC converters based on the switched approach is an economic option to introduce network analysis concepts. Experimental results show that used techniques allow calculate the frequency range operation not only of the electronic components but also the effect of the power supply value on the generators' performance.El propósito de este artículo es presentar un análisis alternativo de circuitos conmutados para diseñar generadores de onda cuadrada, SWG (del Inglés Square Wave Generator. Un SWG puede ser diseñado usando componentes electrónicos de bajo costo, lo cual permite al lector comprender como los convertidores DC-DC y DC-AC basados en la aproximación conmutada es una opción económica para introducir conceptos del análisis de redes. Los resultados experimentales muestran que las técnicas usadas permiten calcular el rango de operación no solo de los componentes electrónicos sino también del efecto que el valor de la fuente de alimentación tiene en el desempeño de los generadores.

F. Sandoval-Ibarra

2007-06-01

199

A Three-phase Dual Active Bridge Bidirectional ZVS DC/DC Converter

This paper discusses the detailed operations of a three-phase dual active bridge bidirectional zero-voltage switching (ZVS) DC/DC converter (TPDAB) which transfers a bidirectional power flow between a 12 V net and a high voltage DC net. The converter is controlled by phase-shift-modulation (PSM) with a fixed duty cycle D=1/3. It features isolation, smoother drawing and injecting current from the 12 V net, smaller capacitances, smaller switch current stress, ZVS over a wide range, high efficiency and a large power handling capability. The mathematic model is analyzed. The soft-switching principle is described and its ZVS criterias are derived. The simulation and experimental results are provided to verify the theoretical analysis.

Xuan, Zhang; Shenghua, Huang; Guoyun, Ning

200

Multistability and Torus Reconstruction in a DC–DC Converter With Multilevel Control

DEFF Research Database (Denmark)

By virtue of their limited size and relatively low costs, multilevel dc-dc converters have come to play an important role in modern industrial power supply systems. When operating in a regime of high corrector gain, such converters can display a variety of new dynamic phenomena associated with the appearance of additional oscillatory modes. Starting in a state where four pairs of stable and unstable period-6 cycles coexist with the basic period-1 cycle, the paper describes a sequence of smooth and nonsmooth bifurcations through which the cycles and their basins of attraction transform as the output voltage is increased. The paper also describes the birth of a multilayered resonance torus through a transverse pitchfork bifurcation of the saddle cycle on an ordinary resonance torus.

Zhusubaliyev, Zhanybai T.; Mosekilde, Erik

2013-01-01

201

Design av en låg spänning, låg effekt DC-DC omvandlare med hög verkningsgrad, teoretiska riktlinjer

In this thesis a predefined design parameters are used to present theoretical guidelines for design of low voltage, and low power DC-DC converter with high power efficiency and low levels of EMI (Electro-Magnetic Interference). This converter is used to alter the DC voltage supplied by the power source. Several DC-DC converters of different types and topologies are described and analyzed. Switched converter of buck topology is found to satisfy the design criteria most adequately and therefore...

Hadzimusic, Rasid

2004-01-01

202

Closed loop control of ZVS half bridge DC-DC converter with DCS PWM Control

Directory of Open Access Journals (Sweden)

Full Text Available

The main drawback of the conventional symmetric control is that both primary switches in the converter operate at hard switching condition. Moreover, during the off-time period of two switches, the oscillation between the transformer leakage inductance and junction capacitance of the switches results in energy dissipation and electromagnetic interference (EMI emissions due to reverse recovery of MOSFETs body diodes. The asymmetric (complementary control was proposed to achieve ZVS operation for HB switches. However, asymmetric stresses distribution on the corresponding components may occur due to the asymmetric duty cycle distribution for the two primary switches. A new control scheme, to be known as duty-cycle shifted PWM (DCS PWM control, is proposed and applied to the conventional HB dc–dc converters to achieve ZVS for both the switches without adding extra components and without adding asymmetric penalties of the complementary control. The concept of this new control scheme is shifting one of the two symmetric PWM driving signals close to the other, such that ZVS may be achieved for the lagging switch due to the shortened resonant interval. Moreover, based on the DCS PWM control, a new half-bridge topology is proposed to achieve ZVS for both the main switches and auxiliary switch by adding an auxiliary switch and diode in the proposed half bridge. ZVS for the switch is achieved by utilizing the energy trapped in the leakage inductance. There are two control schemes. One is open loop and the other is closed loop. In open loop scheme, the given dc-dc converter is operating under disturbance. This disturbance effect is eliminated in closed loop scheme.

JANAPATI SIVAVARA PRASAD

2012-10-01

203

Energy Technology Data Exchange (ETDEWEB)

In this paper a DC-DC power converter for distributed photovoltaic plant architectures is presented. The proposed converter has the advantages of simplicity, high efficiency, and low cost. High efficiency is achieved by having a portion of the input PV power directly fed forward to the output without being processed by the converter. The operation of this converter also allows for a simplified maximum power point tracker design using fewer measurements

Agamy, Mohammed S; Harfman-Todorovic, Maja; Elasser, Ahmed; Steigerwald, Robert L; Sabate, Juan A; Chi, Song; McCann, Adam J; Zhang, Li; Mueller, Frank

2012-09-01

204

Y-source impedance-network-based isolated boost DC/DC converter

DEFF Research Database (Denmark)

A dc-dc converter with very high voltage gain is proposed in this paper for any medium-power application requiring a high voltage boost with galvanic isolation. The proposed converter topology can be realized using only two switches. With this topology a very high voltage boost can be achieved even with a relatively low duty cycle of the switches, and the gain obtainable is presently not matched by any existing impedance network based converter operated at the same duty ratio. The proposed converter has a Y-source impedance network to boost the voltage at the intermediate dc-link side and a push-pull transformer for square-wave AC inversion and isolation. The voltage-doubler rectifier provides a constant dc voltage at the output stage. A theoretical analysis of the converter is presented, supported by simulation and experimental results. A 250 W down-scaled prototype was implemented in the laboratory to demonstrate the feasibility and performance of the proposed converter topology.

Siwakoti, Yam P.; Town, Graham

2014-01-01

205

Multistability and hidden attractors in a multilevel DC/DC converter

DEFF Research Database (Denmark)

An attracting periodic, quasiperiodic or chaotic set of a smooth, autonomous system may be referred to as a "hidden attractor" if its basin of attraction does not overlap with the neighborhood of an unstable equilibrium point. Historically, this condition has implied that the basin of attraction for the hidden set in most cases has been so complicated that special analytic and/or numerical techniques have been required to locate the set. By simulating the model of a multilevel DC/DC converter that operates in the regime of high feedback gain, the paper illustrates how pulse-width modulated control can produce complicated structures of attracting and repelling states organized around the basic switching cycle. This leads us to suggest the existence of hidden attractors in such systems as well. In this case, the condition will be that the basin of attraction does not overlap with the fixed point that represents the basic switching cycle.

Zhusubaliyev, Zhanybai T.; Mosekilde, Erik

2015-01-01

206

This paper presents a novel Zero Current Switching (ZCS)-PWM controlled half-bridge DC-DC converter with High-Frequency (HF)-link. The newly-proposed soft switching DC-DC converter consists of a multi-resonant half-bridge HF-isolated inverter controlled by an asymmetrical PWM scheme and a center-tapped diode rectifier with a choke input filter. In order to attain the wide range of soft-commutation under the condition of constant switching frequency, the single Active Edge-Resonant Cell (AERC) that is composed of a lossless inductor and a switched resonant capacitor is originally employed for the half-bridge inverter arm, providing and assisting ZCS operations in the switching power devices. The ZCS-PWMDC-DC converter treated here is evaluated in experiments using the 800 W-55 kHz prototype. The practical effectiveness of the proposed soft switching DC-DC converter is actually demonstrated and discussed with the experimental results under open loop and closed loop configurations. Finally, the feasibility of the DC-DC converter topology is discussed from the view points of the high efficiency and high power density.

Mishima, Tomokazu; Hiraki, Eiji; Nakaoka, Mutsuo

207

In this paper, a short introductory course to introduce field-programmable gate array (FPGA)-based digital control of dc/dc switching power converters is presented. Digital control based on specific hardware has been at the leading edge of low-medium power dc/dc switching converters in recent years. Besides industry's interest in this topic, from…

Zumel, P.; Fernandez, C.; Sanz, M.; Lazaro, A.; Barrado, A.

2011-01-01

208

In photovoltaic (PV) double-stage grid-connected inverters a high-frequency DC-DC isolation and voltage step-up stage is commonly used between the panel and the grid-connected inverter. This paper is focused on the modeling and control design of DC-DC converters with Peak Current mode Control (PCC) and an external control loop of the PV panel voltage, which works following a voltage reference provided by a maximum power point tracking (MPPT) algorithm. In the proposed overall control structur...

Garcera? Sanfeliu?, Gabriel; Gonza?lez Medina, Raul; Figueres Amoro?s, Emilio; Sandia Paredes, Jesu?s

2012-01-01

209

This paper presents a design and implementation of a converter which has a high power factor for battery charger application. The converter is a combination of a SEPIC converter and a full-bridge dc-dc converter connected in two stages of series circuit. The SEPIC converter works in discontinuous conduction mode and it serves as a power factor corrector so that the shape of input current waveform follows the shape of input voltage waveform. The full-bridge dc-dc converter serves as a regulato...

Efendi Moh. Zaenal; Windarko Novie Ayub; Amir Faisal Moh.

2013-01-01

210

DEFF Research Database (Denmark)

In most power electronics converters, the overall volume is mainly determined by the number of parts and the size of passive components. Integrated magnetics and planar magnetics techniques therefore have been an excellent option in order to reduce the counts and the size of magnetic components, hereby increasing the power density of converters. In this paper, a new planar integrated magnetics (PIM) module for a phase-shift plus duty cycle controlled hybrid bi-directional dc-dc converter is proposed, which assembles one boost inductor and two transformers into an E-I-E core geometry, reducing the number of parts, the total volume of converter, as well as the total core loss of the magnetic components. AC losses in the windings and leakage inductance of the transformers are kept low by interleaving the primary and secondary turns of the transformers. To verify the validity of the design approach and theoretical analysis, a lab prototype employing the PIM module is implemented for a fuel cell application with 20~40 V input voltage and 400 V output voltage. Detailed results from the experimental comparisons demonstrate that the PIM module is fully functional and electromagnetically equivalent to the discrete magnetics and a significant reduction of size can be achieved by using the PIM module.

Ouyang, Ziwei; Zhang, Zhe

2011-01-01

211

DEFF Research Database (Denmark)

This study presents a new DC DC multi-output boost (MOB) converter which can share its total output between different series of output voltages for low- and high-power applications. This configuration can be utilised instead of several single output power supplies. This is a compatible topology for a diode-clamed inverter in the grid connection systems, where boosting low rectified output-voltage and series DC link capacitors is required. To verify the proposed topology, steady-state and dynamic analyses of a MOB converter are examined. A simple control strategy has been proposed to demonstrate the performance of the proposed topology for a double-output boost converter. The topology and its control strategy can easily be extended to offer multiple outputs. Simulation and experimental results are presented to show the validity of the control strategy for the proposed converter.

Nami, A.; Zare, F.

2010-01-01

212

Basic circuits to design switched-based DC-DC converters

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish El propósito de este artículo es doble. Por un lado, se presentan conceptos básicos de circuitos conmutados para diseñar un convertidor CD-CD y, por el otro, se rescatan definiciones de electrónica de potencia asociadas a redes eléctricas simples. En el análisis de esas redes es necesario tomar en c [...] uenta no solo las no idealidades de los convertidores sino también cómo minimizar pérdidas de potencia. Porque las perdidas de potencia pueden ser minimizadas aumentando la frecuencia de reloj de los convertidores conmutados, se presentan resultados experimentales de generadores de reloj. Estos circuitos fueron implementados con componentes de bajo costo Abstract in english The purpose of this paper is twofold. On one hand, basics on switched circuits for designing a DC-DC converter are presented and, on the other hand, power electronics definitions associated with simple electrical networks are mentioned. In the analysis of these networks, it is necessary to take into [...] account not only converters' non-idealities but also how to minimize power losses. Since power losses may be minimized by increasing the clock frequency of switched-based converters, experimental results of basic clock generators are presented. These generators were implemented with low-cost components

F, Sandoval-Ibarra; J.R, Mercado-Moreno; L.H, Urióstegui-Vázquez.

2007-12-01

213

PV and Wind Energy Hybrid Integrated Full-Bridge-DC–DC Converter for a Residential Application

Directory of Open Access Journals (Sweden)

Full Text Available Hybrid power system can be used to reduce energy storage requirements. There is increasing demand for the use of alternate or renewable energy sources to achieve clean and low-cost electricity for Residential Application The PV-wind hybrid system returns the lowest unit cost values to maintain the same level of DPSP as compared to standalone solar and wind systems. For all load demands the levelised energy cost for PV-wind hybrid system is always lower than that of standalone solar PV or wind system. The PV-wind hybrid option is techno-economically viable for rural electrification. This paper proposes a novel integrated converter topology for interfacing between the energy storage system and the dc bus for a residential microgrid application The proposed integrated full-bridge dc–dc converter presents the following features: low number of active devices compared to the converters usually applied to similar applications, low input and output current ripple, high voltage ratio, bidirectional power flow, and galvanic isolation.

G.Revan Sidda

2014-09-01

214

Design Of Vswt With Lcl Resonant Dc-dc Converters For Rl Load

This paper deals with design of variable speed wind turbine (VSWT) with LCL resonantDC-to-DC converter for stand-alone wind energy system with RL load. The wind turbinesystem consists of synchronous generator (SG), full bridge diode rectifier, buck DC- DCconverter and inverter with RL load is present. Based on this electrical model, a Simulinkmodel of the system are simulated by using MATLAB Simulink power system blocks. Thisconverter has advantages like reduced transformer size, reduced filt...

Vijaya Kumar, M.; Annamalai, M.

2012-01-01

215

An imroved design for ZVT DC-DC PWM converters with snubber assisted auxiliary switch

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes an improved design to calculate the snubber auxiliary elements of ZVT DC-DC PWM converters with snubber assisted auxiliary switch. The proposed improved design guidelines are based on the reduction of the conduction losses through the auxiliary circuit. It is accomplished by the unique location of the turn-off snubber capacitor, which is shared by both active switches. By means of this improved design guidelines the converter efficiency can be increased. An efficiency comparative analysis is carried out and the experimental results, obtained from 1 kW, 100 kHz laboratory prototypes, show a relevant improvement in converter efficiency compared to the original converter design. In addition, experimental results also confirm that with the improved design the ZVT PWM converters with snubber assisted auxiliary switch can be competitive with ZVT PWM converters with constant auxiliary voltage source (True PWM ZVS pole.Este artigo propõe uma metodologia de projeto aprimorada para determinação dos componentes auxiliares para o conversor ZVT CC-CC PWM snubber assisted auxiliary switch. O procedimento de projeto proposto é baseado na redução das perdas de condução no circuito auxiliar. Isto é somente possível devido à localização do capacitor snubber de bloqueio, o qual é compartilhado por ambas as chaves ativas. Através do procedimento de projeto proposto o rendimento do conversor pode ser aumentado. Uma análise comparativa do rendimento é apresentada e os resultados experimentais, obtidos de protótipos de laboratório de 1 kW, 100 kHz, mostram uma melhoria relevante em relação ao rendimento apresentado pelo projeto original. Além disso, os resultados experimentais também confirmam que o projeto proposto para o conversor ZVT snubber assisted auxiliary switch torna-o competitivo em relação ao conversor ZVT PWM com fonte auxiliar de tensão constante (true PWM ZVS pole.

J. Russi

2005-03-01

216

An imroved design for ZVT DC-DC PWM converters with snubber assisted auxiliary switch

Scientific Electronic Library Online (English)

Full Text Available Este artigo propõe uma metodologia de projeto aprimorada para determinação dos componentes auxiliares para o conversor ZVT CC-CC PWM snubber assisted auxiliary switch. O procedimento de projeto proposto é baseado na redução das perdas de condução no circuito auxiliar. Isto é somente possível devido [...] à localização do capacitor snubber de bloqueio, o qual é compartilhado por ambas as chaves ativas. Através do procedimento de projeto proposto o rendimento do conversor pode ser aumentado. Uma análise comparativa do rendimento é apresentada e os resultados experimentais, obtidos de protótipos de laboratório de 1 kW, 100 kHz, mostram uma melhoria relevante em relação ao rendimento apresentado pelo projeto original. Além disso, os resultados experimentais também confirmam que o projeto proposto para o conversor ZVT snubber assisted auxiliary switch torna-o competitivo em relação ao conversor ZVT PWM com fonte auxiliar de tensão constante (true PWM ZVS pole). Abstract in english This paper proposes an improved design to calculate the snubber auxiliary elements of ZVT DC-DC PWM converters with snubber assisted auxiliary switch. The proposed improved design guidelines are based on the reduction of the conduction losses through the auxiliary circuit. It is accomplished by the [...] unique location of the turn-off snubber capacitor, which is shared by both active switches. By means of this improved design guidelines the converter efficiency can be increased. An efficiency comparative analysis is carried out and the experimental results, obtained from 1 kW, 100 kHz laboratory prototypes, show a relevant improvement in converter efficiency compared to the original converter design. In addition, experimental results also confirm that with the improved design the ZVT PWM converters with snubber assisted auxiliary switch can be competitive with ZVT PWM converters with constant auxiliary voltage source (True PWM ZVS pole).

J., Russi; M. L., Martins; H. A., Gründling; H., Pinheiro; J. R., Pinheiro; H. L., Hey.

2005-03-01

217

This paper deals with reducing switching loss, reducing voltage and current stresses, and reducing conduction loss due to circulation current. An isolated bidirectional full-bridge dc–dc converter with high conversion ratio, high output power, and soft start-up capability is proposed. The use of a capacitor, a diode, and a flyback converter can clamp the voltage spike caused by the current difference between the currentfed inductor and leakage inductance of the isolation transformer, ...

Umaranjani, T.; Sasikumar, M.

2012-01-01

218

In this paper, a soft-switched Interleaved DC-DC Boost Converter (IBC) for fuel cell is simulated and implemented. The proposed two-phase IBC circuit consists of two identical boost converter connected in parallel and are controlled by interleaved switching signals. But in the conventional IBC switching loss increases with the number of switching devices. To solve this problem, this paper has proposed a soft switched IBC. Detailed analysis has been done to investigate the benefits of soft-sw...

Seyezhai, R.; Harinee Harinee; Nagarajan Nagarajan

2012-01-01

219

Optimal Design and Tradeoff Analysis of Planar Transformer in High-Power DC–DC Converters

DEFF Research Database (Denmark)

The trend toward high power density, high operating frequency, and low profile in power converters has exposed a number of limitations in the use of conventional wire-wound magnetic component structures. A planar magnetic is a low-profile transformer or inductor utilizing planar windings, instead of the traditional windings made of Cu wires. In this paper, the most important factors for planar transformer (PT) design including winding loss, core loss, leakage inductance, and stray capacitance have individually been investigated. The tradeoffs among these factors have to be analyzed in order to achieve optimal parameters. Combined with an application, four typical winding arrangements have been compared to illustrate their advantages and disadvantages. An improved interleaving structure with optimal behaviors is proposed, which constructs the top layer paralleling with the bottom layer and then in series with the other turns of the primary, so that a lower magnetomotive force ratio $m$ can be obtained, as wellas minimized ac resistance, leakage inductance, and even stray capacitance. A 1.2-kW full-bridge dc–dc converter prototype employing the improved PT structure has been constructed, over 96% efficiency is achieved, and a 2.7% improvement, compared with the noninterleaving structure, is obtained.

Ouyang, Ziwei; Thomsen, Ole Cornelius

2012-01-01

220

High Current Planar Transformer for Very High Efficiency Isolated Boost DC-DC Converters

DEFF Research Database (Denmark)

This paper presents a design and optimization of a high current planar transformer for very high efficiency dc-dc isolated boost converters. The analysis considers different winding arrangements, including very high copper thickness windings. The analysis is focused on the winding ac-resistance and transformer leakage inductance. Design and optimization procedures are validated based on an experimental prototype of a 6 kW dcdc isolated full bridge boost converter developed on fully planar magnetics. The prototype is rated at 30-80 V 0-80 A on the low voltage side and 700-800 V on the high voltage side with a peak efficiency of 97.8% at 80 V 3.5 kW. Results highlights that thick copper windings can provide good performance at low switching frequencies due to the high transformer filling factor. PCB windings can also provide very high efficiency if stacked in parallel utilizing the transformer winding window in an optimal way.

Pittini, Riccardo; Zhang, Zhe

2014-01-01

221

Progress on DC-DC Converters for a Silicon Tracker for the sLHC Upgrade

There is a need for DC-DC converters which can operate in the extremely harsh environment of the sLHC Si Tracker. The environment requires radiation qualification to a total ionizing radiation dose of 50 Mrad and a displacement damage fluence of 5 x 1014 /cm2 of 1 MeV equivalent neutrons. In addition a static magnetic field of 2 Tesla or greater prevents the use of any magnetic components or materials. In February 2007 an Enpirion EN5360 was qualified for the sLHC radiation dosage but the converter has an input voltage limited to a maximum of 5.5V. From a systems point of view this input voltage was not sufficient for the application. Commercial LDMOS FETs have developed using a 0.25 ?m process which provided a 12 volt input and were still radiation hard. These results are reported here and in previous papers. Plug in power cards with ×10 voltage ratio are being developed for testing the hybrids with ABCN chips. These plug-in cards have air coils but use commercial chips that are not designed to be radiatio...

Dhawan, S; Chen, H; Khanna, R; Kierstead, J; Lanni, F; Lynn, D; Musso, C; Rescia, S; Smith, H; Tipton, P; M. Weber, M

2009-01-01

222

High-Temperature SOI/SiC-Based DC-DC Converter Suite

Directory of Open Access Journals (Sweden)

Full Text Available A complete design strategy (mechanical and electrical for a 25Ã¢Â€Â‰W 28Ã¢Â€Â‰V/5Ã¢Â€Â‰V dc-dc converter utilizing SiC and SOI electronics is presented. The converter includes a high-temperature SOI-based PWM controller featuring 150Ã¢Â€Â‰kHz operation, a PID feedback loop, maximum duty cycle limit, complementary or symmetrical outputs, and a bootstrapped high-side gate driver. Several passive technologies were investigated for both control and power sections. Capacitor technologies were characterized over temperature and over time at 300CÃ¢ÂˆÂ˜, power inductors designed and tested up to 350CÃ¢ÂˆÂ˜, and power transformers designed and tested up to 500CÃ¢ÂˆÂ˜. Northrop Grumman normally-off SiC JFETs were used as power switches and were characterized up to 250CÃ¢ÂˆÂ˜. Efficiency and mass optimization routines were developed with the data gained from the first prototype. The effects of radiation on SiC and SOI electronics are then discussed. The results of the first prototype module are presented, with operation from 25CÃ¢ÂˆÂ˜ up to an ambient temperature of 240CÃ¢ÂˆÂ˜ .

Brice McPherson

2008-08-01

223

Analysis of Dc/Dc converters with PWM and sliding mode controls

International Nuclear Information System (INIS)

Static and dynamic performances of D C/D C converters with PWM and sliding mode controllers are investigated. To improve the performance of the PWM controller, a linear compensator is proposed and used. For sliding controller, important parameters such as sliding coefficients and filter time constant are carefully computed and used. Finally, a D C/D C buck converter with PWM and sliding controller is designed, modeled and constructed. Theoretical and experimental results are compared and the distinguished features and limitations of each control technique are presented

224

Energy Technology Data Exchange (ETDEWEB)

Especially in automotive engineering, the big aim of electronic device development is to combine minimum possible weight, highest efficiency and low electromagnetic interference. Since there is a wide range of energy storage devices and power consumption requirements are very versatile, there are many possible solutions for electronic power devices, but not all of them will be appropriate for each system. One possible solution concerning dc/dc converters is represented by the phase shift operation for full bridge topologies. This procedure is used for supplying the electrical 14 V system from the high voltage energy storage or, in the other direction, charge the HV battery from the 14 V net or even from an external 230 V / 400 ac net. Finepower has developed 2 prototypes for research, which are presented in this contribution. Another new topology, a bidirectional LLC Converter, is presented as well. Energy consumption is growing and the available space for electronic power devices is held very small, so the power density increases and thermal management becomes more difficult. As dimensions of bus bars, semiconductors or inductive components are shrinking, parasitic influence becomes more and more significant. For getting information about function and influence of parasitics of electronic power devices, simulation is a very important tool since it saves much time and gives the possibility to extract internal dimensions of electrical circuits which cannot be measured in reality. (orig.)

Pledl, Georg; Lutter, Peter [Finepower GmbH, Ismaning (Germany)

2010-07-01

225

International Nuclear Information System (INIS)

The paper describes an experimental study of the bifurcation behaviour of a modular peak current-mode controlled DC-DC boost converter. The parallel-input/parallel-output converter comprises two identical boost circuits and operates in the continuous-current conduction mode. A comparison is made between the results obtained from an experimental converter with those obtained from bifurcation diagrams generated from previous work and waveforms from a new MATLAB/SIMULINK simulation presented in this paper. Another comparison is made between the modular converter diagrams with those of the single boost converter.

226

Abstract:zero-voltage-switching (ZVS) dc?dc converter with specific voltage gain is proposed . The specific voltage is utilized for inverter operation for supplying 3-phase domestic load. It consists of a ZVS boost converter stage and a ZVS half-bridge converter stage and two stages are merged into a single stage. The ZVS boost converter stage provides a continuous input current and ZVS operation of the power switches. The ZVS half-bridge converter stage provides a high voltage gain. The pr...

Anil Kumar Reddy K, Sirisha S.

2013-01-01

227

Optimal Design and Tradeoffs Analysis for Planar Transformer in High Power DC-DC Converters

DEFF Research Database (Denmark)

A planar magnetic is a low profile transformer or inductor utilizing planar windings instead of the traditional windings made of Cu-wires. In this paper, the important factors for planar transformer design including winding loss, core loss, leakage inductance and stray capacitance have been investigated individually. The tradeoffs among these factors have to be analyzed in order to achieve optimal parameters. Combined with a certain application, four typical winding arrangements have been compared to illustrate each their advantages and disadvantages. An improved interleaving structure with optimal behaviors is proposed, which constructs the top layer paralleling with the bottom layer and then in series with the other turns of the primary so that a lower magneto motive force (MMF) ratio m can be obtained as well as minimized AC resistance, leakage inductance and even stray capacitance. A 1.2-kW full-bridge DC-DC converter prototype employing the improved planar transformer structure has been constructed, over96% efficiency is achieved and a 2.7% improvement compared to the non-interleaving structure is obtained.

Ouyang, Ziwei; Thomsen, Ole Cornelius

2010-01-01

228

Planar integrated magnetics design in wide input range DC-DC converter for fuel cell application

DEFF Research Database (Denmark)

In the most power electronics converters, the overall volume is mainly determined by the number of parts and the size of passive components. Integrated magnetics and planar magnetics techniques therefore have been an excellent option in order to reduce the count and the size of magnetic components, hereby increasing the power density of converters. A new planar integrated magnetics (PIM) technique for a phase-shift plus duty cycle controlled hybrid bi-directional DC/DC converter is presented and investigated in this paper. The main magnetic components including one boost inductor and two independent transformers are integrated into an E-I-E core geometry. Utilizing the flux cancellation as the principle of uncoupling, the transformers and the boost inductor are integrated, to reduce the total ferrite volume and core loss. The transformers and inductor are wound in the outer legs and the center legs respectively. The uncoupling effect between them is determined by the winding connections. The middle I-core provides a shared low reluctance flux path, uncoupling the two independent transformers. With the air gaps shift into the center legs, the magnetizing inductance of transformers will not be decreased due to there is no air gap throughout the flux paths generated by the two transformers. The new PIM structure can be extended to other topologies. To verify the validity of design approach and theoretical analysis, a lab prototype with PIM has been built, and tested. Comparing with the discrete structure, the result demonstrated a great improvement in profile and volume without sacrificing electrical performance.

Ouyang, Ziwei; Zhang, Zhe

2010-01-01

229

Directory of Open Access Journals (Sweden)

Full Text Available Well-regulated DC bus voltage is the important point to guarantee the power demand in hybrid vehicle applications. Voltage regulation can be achieved with control method that build switching signal on DC-DC converter. This paper describes design and small scale experimental results of bus voltage regulation control of the DC-DC bidirectional converter with battery and supercapacitor as energy source. The control system consists of two control loops, the outer loop that get DC bus voltage feedback using PI anti-windup back calculation control method. This outer loop will generate a reference current for the inner loop that implement hysteresis control. The inner control loop will compare that reference curent with the source current obtained from the current sensor. Simulation and experimental results show that bus voltage is well-regulated under the load changes with 1% voltage ripple.

Muh. Zakiyullah Romdlony

2012-07-01

230

Efficiency and cost comparison of Si IGBT and SiC JFET isolated DC/DC converters

DEFF Research Database (Denmark)

Silicon carbide (SiC) and other wide band gap devices are in these years undergoing a rapid development. The need for higher efficiency and smaller dimensions are forcing engineers to take these new devices in to considerations when choosing semiconductors for their converters. In this article a Si based converter and a SiC based converter is compared. Both converters are isolated DC/DC converters and were designed for 5 kW nominal outputs. Test setups for both converters were built and tested. The hardware differences between the two converters are described and performance is compared. An efficiency of above 97 % for the SiC JFET and over 90 % for the SI IGBT converter was measured. Cost differences between the two converters have been analyzed, showing that 772 days of operation are needed for the SiC converter costs to break even with the Si IGBT converter costs.

Nielsen, Rasmus Ørndrup; Török, Lajos

2013-01-01

231

Efficiency and Cost Comparison of Si IGBT and SiC JFET Isolated DC/DC Converters

DEFF Research Database (Denmark)

Silicon carbide (SiC) and other wide band gap devices are in these years undergoing a rapid development. The need for higher efficiency and smaller dimensions are forcing engineers to take these new devices in to considerations when choosing semiconductors for their converters. In this article a Si based converter and a SiC based converter is compared. Both converters are isolated DC/DC converters and were designed for 5 kW nominal outputs. Test setups for both converters were built and tested. The hardware differences between the two converters are described and performance is compared. An efficiency of above 97 % for the SiC JFET and over 90 % for the SI IGBT converter was measured. Cost differences between the two converters have been analyzed, showing that 772 days of operation are needed for the SiC converter costs to break even with the Si IGBT converter costs.

Nielsen, Rasmus Ørndrup; Török, Lajos

2013-01-01

232

Classical linear amplifiers such as A, AB and B offer very good linearity suitable for RF power amplifiers. However, its inherent low efficiency limits its use especially in base-stations that manage tens or hundreds of Watts. The use of linearization techniques such as Envelope Elimination and Restoration (EER) allow an increase of efficiency keeping good linearity. This technique requires a very fast dc-dc power converter to provide variable voltage supply to the power amplifier. In this pa...

Garci?a Sua?rez, Oscar; Vasic, Miroslav; Alou Cervera, Pedro; Oliver Rami?rez, Jesu?s Angel; Di?az Lo?pez, Daniel; Cheng, Pengming; Cobos Ma?rquez, Jose? Antonio

2011-01-01

233

Energy Technology Data Exchange (ETDEWEB)

Fuel cells are a promising alternative for clean and efficient energy production. A fuel cell is probably the most demanding of all distributed generation power sources. It resembles a solar cell in many ways, but sets strict limits to current ripple, common mode voltages and load variations. The typically low output voltage from the fuel cell stack needs to be boosted to a higher voltage level for grid interfacing. Due to the high electrical efficiency of the fuel cell, there is a need for high efficiency power converters, and in the case of low voltage, high current and galvanic isolation, the implementation of such converters is not a trivial task. This thesis presents galvanically isolated DC-DC converter topologies that have favorable characteristics for fuel cell usage and reviews the topologies from the viewpoint of electrical efficiency and cost efficiency. The focus is on evaluating the design issues when considering a single converter module having large current stresses. The dominating loss mechanism in low voltage, high current applications is conduction losses. In the case of MOSFETs, the conduction losses can be efficiently reduced by paralleling, but in the case of diodes, the effectiveness of paralleling depends strongly on the semiconductor material, diode parameters and output configuration. The transformer winding losses can be a major source of losses if the windings are not optimized according to the topology and the operating conditions. Transformer prototyping can be expensive and time consuming, and thus it is preferable to utilize various calculation methods during the design process in order to evaluate the performance of the transformer. This thesis reviews calculation methods for solid wire, litz wire and copper foil winding losses, and in order to evaluate the applicability of the methods, the calculations are compared against measurements and FEM simulations. By selecting a proper calculation method for each winding type, the winding losses can be predicted quite accurately before actually constructing the transformer. The transformer leakage inductance, the amount of which can also be calculated with reasonable accuracy, has a significant impact on the semiconductor switching losses. Therefore, the leakage inductance effects should also be taken into account when considering the overall efficiency of the converter. It is demonstrated in this thesis that although there are some distinctive differences in the loss distributions between the converter topologies, the differences in the overall efficiency can remain within a range of a few percentage points. However, the optimization effort required in order to achieve the high efficiencies is quite different in each topology. In the presence of practical constraints such as manufacturing complexity or cost, the question of topology selection can become crucial. (orig.)

Vaisanen, V.

2012-07-01

234

Non-Inverting Buck-Boost Converter for Fuel Cell Applications

DEFF Research Database (Denmark)

Fuel cell DC/DC converters often have to be able to both step-up and step-down the input voltage, and provide a high efficiency in the whole range of output power. Conventional negative output buck-boost and non-inverting buck-boost converters provide both step-up and step-down characteristics. In this paper the non-inverting buck-boost with either diodes or synchronous rectifiers is investigated for fuel cell applications. Most of previous research does not consider the parasitic in the evaluation of the converters. In this study, detailed analytical expressions of the efficiencies for the system composed of fuel cell system and interfacing converter, considering the parasitics, are presented. It is concluded that the implementation with synchronous rectifiers provides the highest efficiency in the whole range of the fuel cell power, and its efficiency characteristic is more suitable for fuel cell applications than the implementation with diodes.

Schaltz, Erik; Rasmussen, Peter Omand

2008-01-01

235

Implementation of Buck-Boost Converter with Coupled Inductor for Photo-Voltaic System

Directory of Open Access Journals (Sweden)

Full Text Available The solar energy is a very interesting alternative on supplement the electrical system generation. In this paper, a photovoltaic based system is obtained from a boost cascaded with a buck converter along with Coupled inductor. Due to its novel operating modes, high efficiency can be achieved because there is only one switch operating at high frequency at a time, and the converter allows the use of power MOSFET and ultra-fast reverse recovery diode. This paper begins with theoretical analysis and modeling of this boost–buck converter. The model indicates that the coupled inductance will lead to an increase in the gain and the decrease in ripples. Finally, this paper analyzes and describes step by step the process of designing, and simulation of high efficiency low ripple voltage buck boost DC-DC converter for the photovoltaic solar conversion system

M.S. Subbulakshmi

2014-12-01

236

Topological variations of the inverse dual converter for high-power dc-dc distribution systems

New dc-to-dc converter topologies are presented which are suitable for high density high power supplies. Topological variations of the basic inverse dual converter (IDC) circuit such as the transformer coupled, the multiphase and the multipulse derivation of the single phase IDC have been analyzed and some simulation results have been presented. The single phase IDC offers a buck-boost operation over wide range without transformer, bidirectional power flow, and complementary commutation of the switches. The topologies examined in this paper have additional features such as lower device and component stresses, and smaller filter requirements, resulting in smaller size and weight. Some performance and possible applications are also examined. IDCs for serial and parallel power distribution, and ac tapping of the IDC are discussed.

Ehsani, Mehrdad; Laskai, Laszlo

237

The design of a bidirectional dc-dc power converter specifically for a distributed energy application is presented. The existing two different DC voltage battery bank of the distributed generation needs to interlink each other using a bi-directional dc-dc converter in order to minimize the unbalance of the output load currents of the three inverters connected to electric grid system. Through this connection, a current can flow from one system to another or vice versa depending on which system...

Cultura Ii, Ambrosio B.; Salameh, Ziyad M.

2012-01-01

238

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a design and implementation of a converter which has a high power factor for battery charger application. The converter is a combination of a SEPIC converter and a full-bridge DC-DC converter connected in two stages of series circuit. The SEPIC converter works in discontinuous conduction mode and it serves as a power factor corrector so that the shape of input current waveform follows the shape of input voltage waveform. The full-bridge DC-DC converter serves as a regulator of output voltage and operates at continuous conduction mode. The experimental results show that the power factor of this converter system can be achieved up to 0.96.

Moh. Zaenal Efendi

2013-12-01

239

DEFF Research Database (Denmark)

DC microgrids or nanogrids have attracted increasing research interest in recent years. Therefore, as a critical component, dc-dc converters with multiple inputs are required. In this paper, a dual-input interleaved buck/boost converter is proposed and its corresponding power flow control methods are analyzed and designed accordingly. Furthermore, the design guidelines are discussed. Finally, in order to verify the validity of this study, the measurement results are presented.

Mira Albert, Maria del Carmen; Zhang, Zhe

2015-01-01

240

The current paper deals with a multi-objective design approach of power converters applied to a DC-DC buck structure. This approch consists on optimizing a preselected power architecture by minimizing a multi-objective function (volume and time response) under multi-physic constraints (efficiency, thermal, electromagnetic compatibility and control). This multi-objective optimization allows evaluating the impact of the control aspect on the converter design by considering the control criteria ...

Cherif Larouci; Kamal Ejjabraoui; Pierre Lefranc; Claude Marchand

2012-01-01

241

This document proposes analysing and designing two control strategies for permanent current DC-DC buck converter. These kinds of electronic devices convert a constant-voltage to a lower constant-voltage (nonlinearity characteristics being demonstra- ted). Two nonlinear control techniques are shown. The first is a conventional optimal proportional error and integral error (PI) controller based on minimising integral of time per squared errors (ITSE) criteria. A model of the plant at ...

Lina Morales Laguado; Harold Chamorro; Jairo Soriano

2010-01-01

242

Directory of Open Access Journals (Sweden)

Full Text Available Abstract:zero-voltage-switching (ZVS dc?dc converter with specific voltage gain is proposed . The specific voltage is utilized for inverter operation for supplying 3-phase domestic load. It consists of a ZVS boost converter stage and a ZVS half-bridge converter stage and two stages are merged into a single stage. The ZVS boost converter stage provides a continuous input current and ZVS operation of the power switches. The ZVS half-bridge converter stage provides a high voltage gain. The principle of operation and system analysis are presented. The specific voltage is used to obtain a 200 volts Line to Line RMS AC supply through inverter operation. The supply is in turn used for a 3-Phase load like operation and speed control of 3-Phase Squirrel cage Induction motor. Keywords: Boost converter, Zero voltage switching, Coupled inductor, Specific voltage gain, Soft switching technique, Inverter, Speed control of Induction motor.

ANIL KUMAR REDDY.K, SIRISHA.S

2013-08-01

243

Development of a DC-DC conversion powering scheme for the CMS Phase-1 pixel upgrade

A novel powering scheme based on the DC-DC conversion technique will be exploited to power the CMS Phase-1 pixel detector. DC-DC buck converters for the CMS pixel project have been developed, based on the AMIS5 ASIC designed by CERN. The powering system of the Phase-1 pixel detector is described and the performance of the converter prototypes is detailed, including power efficiency, stability of the output voltage, shielding, and thermal management. Results from a test of the magnetic field tolerance of the DC-DC converters are reported. System tests with pixel modules using many components of the future pixel barrel system are summarized. Finally first impressions from a pre-series of 200 DC-DC converters are presented.

Feld, Lutz Werner; Karpinski, Waclaw; Klein, Katja; Lipinski, Martin; Preuten, Marius; Max Rauch; Rittich, David Michael; Sammet, Jan Domenik; Wlochal, Michael

2014-01-01

244

Scientific Electronic Library Online (English)

Full Text Available En este trabajo se presentan resultados experimentales que confirman la validez de una nueva técnica de control digital, por modulación de ancho de pulso (PWM- Digital), para convertidores de potencia DC-DC y DC-AC. El controlador PWM-Digital combina el esquema de control por promedio cero de la din [...] ámica del error (ZAD), ya reportado en la literatura, con el esquema de control por inducción al punto fijo (FPIC) aún en fase de experimentación. El diseño ha sido validado experimentalmente, usando la plataforma digital DSpace, en convertidores DC-DC y DC-AC de baja potencia. Los diagramas de bifurcaciones, calculados numéricamente en la etapa de diseño, concuerdan en un alto porcentaje con los obtenidos en la etapa experimental. Cuando el sistema opera en zona estable se obtiene buen comportamiento a la salida (regulación en el caso DC-DC y rastreo en el caso DC-AC), con bajo error y rechazo a perturbaciones. Abstract in english In this paper, we show numerical and experimental results obtained when a new PWM-digital control technique is applied to DC-DC and DC-AC converters. The controller combines ZAD (zero average dynamics) and FPIC (Fixed point inducting controller) strategies. The first one has been reported in the lit [...] erature in the last years and the second one is still in experimental phase. The design has been tested in an experimental way in low power DC-DC and DC-AC converters, using DSpace platform. Numerical and experimental bifurcation diagrams agree. When the system is working in a stable range it has very good performance, showing low error and robustness.

FREDY EDIMER, HOYOS VELASCO; FABIOLA, ANGULO GARCIA; JOHN ALEXANDER, TABORDA GIRALDO; GERARD, OLIVAR TOST.

2010-12-01

245

Directory of Open Access Journals (Sweden)

Full Text Available This Letter presents a low start-up voltage dc–dc converter for low-power thermoelectric systems which uses a native n-type MOS transistor as the start-up switch. The start-up voltage of the proposed converter is 300 mV and the converter does not need batteries to start up. The negative voltage control is proposed to reduce the leakage current caused by native n-type transistor and increase the efficiency. The proposed converter was designed using standard 0.18 µm CMOS process with chip size of 0.388 mm^2. The peak efficiency is 63% at load current of 1.5 mA. The proposed converter provides output voltage >1 V at maximum load current of 3.2 mA.

Pui-Sun Lei

2015-01-01

246

A Novel Dual-input Isolated Current-Fed DC-DC Converter for Renewable Energy System

DEFF Research Database (Denmark)

In this paper, a novel isolated current-fed DC-DC converter (boost-type) with two input power sources based on multi-transformer structure, which is suitable for fuel cells and super-capacitors hybrid energy system, is proposed and designed. With particular transformer windings connection strategy, the proposed converter can draw power from two different DC sources with lower voltage and deliver it to the higher voltage DC bus or load individually and simultaneously. The detailed operation principle of the proposed converter has been analyzed in dual-input mode and single-input mode, respectively. Furthermore, the method to increase the number of input ports, the magnetic integration structure, and ground loop decoupling are discussed. Experimental results from the lab prototype converter with two DC voltage sources verify the validity of the theoretical analysis and design of the converter.

Zhang, Zhe; Thomsen, Ole Cornelius

2010-01-01

247

International Nuclear Information System (INIS)

Research highlights: ? Hybrid electric power system for a real surface tramway. ? Hybrid system based on PEM fuel cell with dc/dc converter and Ni-MH battery. ? New control strategy for the energy management of the tramway. ? Hybrid system demonstrated to meet appropriate driving cycle of the tramway. -- Abstract: This paper presents a hybrid electric power system for a real surface tramway. The hybrid system consists of two electrical energy sources integrating a single dc/dc converter to provide the power demanded by the tramway loads (four electric traction motors and auxiliary services): (1) a Polymer Electrolyte Membrane (PEM) fuel cell (FC) as the primary and (2) a rechargeable Ni-MH battery as electrical energy storage to supplement the FC over the driving cycle. According to the requirements of the real driving cycle of the tramway, it was considered a 200 kW PEM FC system with two FCs connected in parallel and a 34 Ah Ni-MH battery. The PEM FC and Ni-MH battery models were designed from commercially available components. The power conditioning system provides the appropriate power for the tramway. It is composed of: (1) a unique dc/dc boot converter which adapts the FC output voltage to the 750 V traction standard dc bus; (2) three phase inverters to drive properly each electric motors; and (3) a braking chopper to dissipate excess of regenerative braking energy. Suitable state machine control architecture is presented for the hybrid system, its objecd for the hybrid system, its objective being to provide demanded power by the driving cycle, optimizing the energy generated. Following this objective, a new state machine control strategy based on eight states decides the operating point of each component of the system and a cascade control structure allows achieving the operating points determined by the strategy. Simulation results of the real driving cycle of the tramway check the adequacy of the hybrid electric power system.

248

Application of Multi-port Bidirectional DC-DC Converter to Fuel Cell Vehicle Driving in JC08 Mode

A fuel cell-EDLC hybrid power system with a multi-port bidirectional DC-DC converter has been recently proposed for extending lifetime of a fuel cell due to smoothing the output current of the fuel cell. This paper studies the performance of the hybrid power system when a fuel cell vehicle drives in the JC08 mode using a simulation model. The simulation results indicate that even if the load current fluctuates, the output current of the fuel cell could be maintained at almost constant values with an assist from the EDLC although small spikes are observed.

Tanaka, Katsunori; Katayama, Noboru; Kogoshi, Sumio; Fukada, Takafumi; Ogawa, Makoto

249

Directory of Open Access Journals (Sweden)

Full Text Available A closed loop ZVS-ZCS bidirectional dc-dc converter is modeled and appropriate digital simulations are provided. With the ZVS-ZCS concept, the MATLAB simulation results of application to a fuel cell and battery application have been obtained whenever the input voltage exceeds the given 24V, at that time the load voltage will change from 180V to 230V. But due to this usage the load is disturbed and there is instability in the model. Using closed loop the output voltage is stabilized.

V. V. Subrahmanya Kumar Bhajana

2010-07-01

250

A closed loop ZVS-ZCS bidirectional dc-dc converter is modeled and appropriate digital simulations are provided. With the ZVS-ZCS concept, the MATLAB simulation results of application to a fuel cell and battery application have been obtained whenever the input voltage exceeds the given 24V, at that time the load voltage will change from 180V to 230V. But due to this usage the load is disturbed and there is instability in the model. Using closed loop the output voltage is stabilized.

Subrahmanya Kumar Bhajana, V. V.; Rama Reddy, S.

2010-01-01

251

Electrical power system in future uninterruptible power supply (UPS) or electrical vehicle (EV) may employ hybrid energy sources, such as fuel cells and super-capacitors. It will be necessary to efficiently draw the energy from these two sources as well as recharge the energy storage elements by the DC bus. In this paper, a bidirectional isolated DC-DC converter controlled by phase-shift and duty cycle for the fuel cell hybrid energy system is analyzed and designed. The proposed topology mini...

Zhang, Zhe; Ouyang, Ziwei; Thomsen, Ole Cornelius; Andersen, Michael A. E.

2011-01-01

252

DEFF Research Database (Denmark)

A common limitation of power coupling effect in some known multiple-input dc-dc converters has been addressed in many literatures. In order to overcome this limitation, a new concept for decoupling the primary windings in the integrated multiple-winding transformers based on 3-dimensional (3D) space orthogonal flux is proposed in this paper. And thus a new geometry core and relative winding arrangements are proposed in accordance with the rthogonal flux decoupling technology. Due to the four secondary windings are arranged in a quadratic pattern at the base core plate with the two perpendicular primary windings, a name of “four quadrants integrated transformers” (FQIT) is therefore given to the proposed construction. Since the two primary windings are uncoupled, the FQIT allows the two input power stages to transfer the energy into the output load simultaneously or at any timemultiplexing scheme, which can optimize the utilization of diversified power energy sources, simplify the system structure, improve the flexibility and reduce the overall cost, so they are attractive for the hybrid renewable power system. Section IV initiates a discussion for the advantages of the FQIT. In order to verify the feasibility of the FQIT in multiple-input converter, a dual-input isolated boost dc-dc converter employing with the FQIT is designed and tested. The results have excellently demonstrated that the two input power stages can be operated independently and the correctness of all the analysis in the paper.

Ouyang, Ziwei; Andersen, Michael A. E.

2012-01-01

253

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a soft-switched Interleaved DC-DC Boost Converter (IBC for fuel cell is simulated and implemented. The proposed two-phase IBC circuit consists of two identical boost converter connected in parallel and are controlled by interleaved switching signals. But in the conventional IBC switching loss increases with the number of switching devices. To solve this problem, this paper has proposed a soft switched IBC. Detailed analysis has been done to investigate the benefits of soft-switched IBC compared to that of conventional uncoupled and directly coupled IBC. The converter circuit is constructed using power MOSFET as power switch. The PWM is generated by PIC18F4450 microcontroller. In this paper, the analysis of the converter is presented which is verified by the results of simulation and experimentation.

R. Seyezhai

2012-09-01

254

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a soft-switched Interleaved DC-DC Boost Converter (IBC for fuel cell is simulated and implemented. The proposed two-phase IBC circuit consists of two identical boost converter connected in parallel and are controlled by interleaved switching signals. But in the conventional IBC switching loss increases with the number of switching devices. To solve this problem, this paper has proposed a soft switched IBC. Detailed analysis has been done to investigate the benefits of soft-switched IBC compared to that of conventional uncoupled and directly coupled IBC. The converter circuit is constructed using power MOSFET as power switch. The PWM is generated by PIC18F4450 microcontroller. In this paper, the analysis of the converter is presented which is verified by the results of simulation and experimentation.

R. Seyezhai

2012-06-01

255

A fuel cell/electric double layer capacitor hybrid power source using a multi-port bidirectional DC-DC converter has been developed to reduce load variations for the purpose of extending fuel cell life. The proposed converter operates to maintain the fuel cell current, load voltage and bus voltage at constant values with a digital signal processor. The effect of the proposed converter is evaluated. The charging or discharging current of the EDLC rapidly changes along with step loading, and the voltage and current of the fuel cell are maintained at the constant values. Short-time transient responses show that the fuel cell current ripples 0.35 A at 1 A load change in 6 ms.

Katayama, Noboru; Kogoshi, Sumio

256

Development of TMS320F2810 DSP Based Bidirectional buck-boost Chopper

Directory of Open Access Journals (Sweden)

Full Text Available A DC - DC converter is an electronic circuit which converts a source of direct current (DC from one voltage level to another. It is a class of power converter. One common application of DC - DC converters is DC motor control. The Buck - Boost Chopper is a type of DC - DC converter. They are static devices which are used to obtain variable DC voltage from the source of constant DC voltage. Besides the saving in power, Buck-Boost choppers offer greater efficiency, faster response, lower maintenance, smooth control and small size. Even though Buck Boost choppers have several advantages, they can't transfer power from either sides. So a unidirectional DC/DC converter is designed to flow energy on both sides by replacing diodes with controllable switch forming a Bidirectional DC/DC converter. The output DC level is controlled by varying the time for which the supply is connected to the circuit.

Mr. K.S. Chakradhar*1,

2014-06-01

257

Design and Robustness Analysis of a PID Based Sliding Mode Controller for a dc-dc Converter

Directory of Open Access Journals (Sweden)

Full Text Available This study deals with the design and analysis of a dc-dc converter operating in continuous conduction mode with Proportional-Integral-Derivative control and PID based Sliding Mode Control (SMC. A small signal model is developed using Switching Flow Graph (SFG from which the control coefficients for the PID controller is selected. PID based SMC uses a control law which constrains the weighted sum of the voltage error, its derivatives and the integral of the voltage error to zero. The equivalent control technique is used in its design which makes the converter more suitable for fixed frequency operation. Sensitivity of these controllers to supply voltage disturbances and load disturbances is studied and results are presented.

D.M. Mary Synthia Regis Prabha

2012-02-01

258

SPECTRAL ANALYSIS OF BUCK AND SEPIC CONVERTERS

Directory of Open Access Journals (Sweden)

Full Text Available Switched mode power converters generate harmonic currents, which will be injected into the utility grid, causing distortion of the utility waveform. They also become a source for the generation of EMI, which may affect the communication systems. This work is about the design and evaluation of the two most frequently used SMPS used in step down mode of operation: the Buck converter and the Sepic converter working in step-down mode of operation. These converters were designed using optimized equations for their components ratings. Simulation results show that although the Buck output voltage is low in harmonics, it has high harmonic contents in currents circulating in its inductor and diode, and hence requires strong filtering. The Sepic converterhas lower harmonic contents than the Buck converter.

CHAKIB ALAOUI

2011-02-01

259

This paper presents a soft-switching pulse width modulation (PWM) non-isolated bi-directional dc–dc converter embedding an edge-resonant switched capacitor (ER-SWC) cell. The conceptual dc–dc converter treated herein can achieve high-frequency zero-current soft-switching turn-on and zero-voltage soft-switching turn-off operations in the active switches. Those advantageous properties enable a wide range of soft-switching operations together with a high-voltage step- up conversion ratio wit...

Saritha Thomas; Rabiya Rasheed

2014-01-01

260

Abstract-In this paper, an extended run time DC UPS system structure with fuel cell and supercapacitor is investigated. A wide input range bi-directional dc-dc converter is described along with the phase-shift modulation scheme and phase-shift with duty cycle control, in different modes. The delivered power and peak current are analyzed and calculated. The key parameters of the bi-directional dc-dc converter, the relationships between the input voltage, phase-shift angle,...

Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.; Schmidt, Jacob D.; Nielsen, Henning R.

2009-01-01

261

Designing Controller for Joined Dynamic Nonlinear PEMFC and Buck Converter System

Directory of Open Access Journals (Sweden)

Full Text Available Designing controller for a class of dynamical nonlinear model for Polymer Electrolyte Membrane Fuel Cell (PEMFC is discussed in this paper inwhich the PEMFC system is used for powering a Notebook PC (Processing Computer. The power requirement of a Notebook PC varies significantly under different operational conditions. The proposed feedback controller is applied for the buck dc/dc converter to stabilize the load voltage at a desirable level under various operational conditions. The simulation results show the promising performance of the proposed controller at the different operating conditions.

M.R. Rahimi Khoygani

2014-03-01

262

Continuation of periodic orbits in a ZAD-strategy controlled buck converter

International Nuclear Information System (INIS)

This paper concerns the dynamics of a Zero Average Dynamics (ZAD) controlled DC-DC Buck converter. We study the continuation problem of periodic orbits in a periodically forced piecewise-smooth system through the ranges of existence and stability. These orbits can have different configuration and periodicity, and they end in a transition to chaotic bands when a parameter is varied. Three assumptions (a symmetry assumption, a zero-average assumption and a regulation assumption) allows existence ranges to be predicted analytically, and there is only a final efficient numerical step. Stability is checked through Floquet exponents, which are also analytically computed

263

New non-linear control strategy for non-isolated DC/DC converter with high voltage ratio

Energy Technology Data Exchange (ETDEWEB)

In this paper, a non-isolated DC/DC converter with high voltage ratio is proposed to allow the interface between a low voltage power source like fuel cell and a high voltage DC bus. To take into account the low voltage-high density characteristics of power sources, a cascaded structure composed of two sub-converters has been chosen and allows obtaining a high voltage ratio. The choice of each sub-converter is based on the requirements of the source and its performances. Consequently, we have chosen a three-interleaved boost converter as the 1st sub-converter whereas the 2nd sub-converter is a three-level boost converter. The control of the whole system is realized thanks to energetic trajectories planning based on flatness properties of the system. The control of both the current and the balance of voltage across the output serial capacitors of the three-level boost converter is ensured by non-linear controllers based on a new non-linear model. Experimental results allow validating the proposed power architecture and its associated control. (author)

Shahin, A.; Huang, B.; Martin, J.P.; Pierfederici, S.; Davat, B. [Groupe de Recherche en Electronique et en Electrotechnique de Nancy - INPL - Nancy Universite, 2, Avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy Cedex (France)

2010-01-15

264

Directory of Open Access Journals (Sweden)

Full Text Available The power converter is one of the essential elements for effective use of renewable power sources. This paper focuses on the development of a circuit simulation model for maximum power point tracking (MPPT evaluation of solar power that involves using different buck-boost power converter topologies; including SEPIC, Zeta, and four-switch type buck-boost DC/DC converters. The circuit simulation model mainly includes three subsystems: a PV model; a buck-boost converter-based MPPT system; and a fuzzy logic MPPT controller. Dynamic analyses of the current-fed buck-boost converter systems are conducted and results are presented in the paper. The maximum power point tracking function is achieved through appropriate control of the power switches of the power converter. A fuzzy logic controller is developed to perform the MPPT function for obtaining maximum power from the PV panel. The MATLAB-based Simulink piecewise linear electric circuit simulation tool is used to verify the complete circuit simulation model.

Jaw-Kuen Shiau

2014-08-01

265

DEFF Research Database (Denmark)

This paper presents the design of a low input (24 V) and variable high output voltage (0-2.5 kV) bidirectional dc-dc converter for driving a capacitive actuator. The topology is a digitally controlled bidirectional flyback converter with a variable frequency control. The objective is, to design the converter for efficiently charging and discharging the capacitive actuator from 0 V to 2.5 kV and vice versa, respectively. The converter is used to drive a dielectric electro active polymer (DEAP) based capacitive incremental actuator, which has the potential to be used in automotive (e.g., EVs), space and medical industries. The design of the bidirectional flyback converter to charge and discharge a 400 nF capacitive actuator is presented, when 4 kV and 4.5 kV high voltage MOSFETs are used on the secondary high voltage side. The experimental results and efficiency measurements of the converter with the proposed design are provided

Thummala, Prasanth; Zhang, Zhe

2014-01-01

266

TID and displacement damage effects are studied for vertical and lateral power MOSFETs in five different technologies in view of the development of radiation-tolerant fully integrated DC-DC converters. Investigation is pushed to the very high level of radiation expected for an upgrade to the LHC experiments. TID induces threshold voltage shifts and, in n-channel transistors, source-drain leakage currents. Wide variability in the magnitude of these effects is observed. Displacement damage increases the on-resistance of both vertical and lateral high-voltage transistors. In the latter case, degradation at high particle fluence might lead to a distortion of the output characteristics curve. HBD techniques to limit or eliminate the radiation-induced leakage currents are successfully applied to these high-voltage transistors, but have to be used carefully to avoid consequences on the breakdown voltage.

Faccio, F; Michelis, S; Faccio, Federico; Fuentes, C; Allongue, B; Sorge, R; Orlandi, S

2010-01-01

267

DC/DC converter has a transformer having primary coils connected to an input side and secondary coils connected to an output side. Each primary coil connects a full-bridge circuit comprising two switches on two legs, the primary coil being connected between the switches on each leg, each full-bridge circuit being connected in parallel wherein each leg is disposed parallel to one another, and the secondary coils connected to a rectifying circuit. An outer loop control circuit that reduces ripple in a voltage reference has a first resistor connected in series with a second resistor connected in series with a first capacitor which are connected in parallel with a second capacitor. An inner loop control circuit that reduces ripple in a current reference has a third resistor connected in series with a fourth resistor connected in series with a third capacitor which are connected in parallel with a fourth capacitor.

Lai, Jih-Sheng (Blacksburg, VA); Liu, Changrong (Sunnyvale, CA); Ridenour, Amy (Salem, VA)

2009-04-14

268

International Nuclear Information System (INIS)

The solar energy has been drawing attention of the whole world as a clean and infinite energy, since the globe resource, the globe ecology and so on came into question. The wide applications of the solar energy are being expected in a range from electric power plants to household systems. But the output power induced in the photovoltaic modules is influenced by an intensity of the solar radiation, a temperature of the solar cells and so on, so the various useful forms of the solar energy are being proposed for a purpose of stable power supply. a system described in this paper is a small scaled photovoltaic system with storage batteries. This paper describes the theoretical analyses of the photovoltaic system using a resonant DC-DC converter in order to clarify a desirable circuit condition, besides the experimental results of the battery charging characteristics are presented

269

This paper presents the design and analysis of a high efficiency, PWM (Pulse-Width-Modulation) Buck converters for mobile phone applications. The steady-state and average-value models for the proposed converter are developed and simulated. A practical design approach which aims at systematizing the procedure for the selection of the control parameters is introduced. The switching losses are reduced by using soft switching, additionally, a simple analog and digital form of th...

Benlafkih Abdessamad; Krit Salah-Ddine; Chafik Elidrissi Mohamed

2012-01-01

270

International Nuclear Information System (INIS)

In this paper, we propose a new design procedure to determine the optimal size of a piezoelectric transformer (PT) for DC/DC converter applications. We examined several parameters, which allows us to produce a piezoelectric transformer with optimal efficiency and which has an optimal range for regulating voltage. The characteristics of a piezoelectric transformer (PT) are well known when the load impedance is a pure resistor. However, when piezoelectric transformers are used in AC/DC or DC/DC converter applications, it requires the presence of a rectifier circuit block. A rectifier is usually a nonlinear device which does not act like a pure resistor. We began by modeling a full-wave rectifier directly in order to understand the design constraint variables such as the maximum mechanical current, the piezoelectric transformer configuration, and the energy balance of the PT configuration. In our final design, a stacked disk-type piezoelectric transformer with radial-mode vibration was chosen due to the large number of design parameters required. In our new design procedure, instead of just looking at the typical optimal loading condition of the PT, we used the concept of a maximum mechanical current to determine the new optimal efficiency which is suitable for voltage regulation. From our results we found that the size of the piezoelectric transformer and efficiency are trade-offs which means that they have an inverse relationship. In summary, we developed a new design ip. In summary, we developed a new design procedure to determine the optimal size of a piezoelectric transformer, which we found to be small but with high efficiency so as to provide an optimal range for regulating voltage

271

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a new PWM Multi phase DC-DC converter under current mode control with an auxiliary circuit which provides zero voltage switching in order to meet the power supply requirements of the processors of modern electronic equipments like laptops, mobiles, and PDAs etc which require more than 70 A current, lower voltage and better transient response.The multi phase topology benefits in high current, good efficiency and better current transient response. High current multi phase buck converters found applications in advanced data control, solid state lasers, communication equipment and Pentium processors etc. In this paper designed of three phase DC-DC converter 100W, 12V/1V under current mode control is discussed in detail and the simulation results are presented to support the theoretical analysis.

Nittala S K Sastry

2012-06-01

272

This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high-frequency transformer; this structure minimizes the number of the switching transistors and their associate gate driver components. With phase-shift control strategy, all the switches are operated under zero-vo...

Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

2012-01-01

273

Improved Dynamic Response of Buck Converter using Fuzzy Controller

This paper presents comparative performance of Buck Converter in both open as well as closed loop. With the help state equations Mathematical Model of Buck Converter is designed in MATLAB/SIMULINK. The obtained output response of open loop Buck Converter is sluggish, not optimum and consists of peak overshoots. PI Controller is used in closed loop model of Buck Converter. Output Voltage is compared with a reference signal, which then is processed through a controller (PI/Fuzzy). The obtained ...

Nagulapati Kiran; Ch Varaha Narasimha Raja

2014-01-01

274

DEFF Research Database (Denmark)

Energy production from renewable energy sources is continuously varying, for this reason energy storage is becoming more and more important as the percentage of green energy increases. Newly developed fuel cells can operate in reverse mode as electrolyzer cells; therefore, they are becoming an attractive technology for energy storage grid-tie applications. In this application dc-dc converter optimization is very challenging due to the large voltage range that the converter is expected to operate. Moreover, the fuel-electrolyzer cell side of the converter is characterized by low voltage and high current. Dc-dc converter efficiency plays a fundamental role in the overall system efficiency since processed energy is always flowing through the converter; for this reason, loss analysis and optimization are a key component of the converter design. The paper presents an isolated full bridge boost dc-dc converter (IFBBC) designed for this new application focusing on losses analysis. The system topology is briefly discussed and the major concerns related to the system, cells stacks and converter operating points are analyzed. The dc-dc converter losses are modeled and presented in detail; the analysis is validated on adc-dc converter prototype rated at 6 kW 30-80 V 0-80 A on the low voltage side and 700-800 V on the high voltage side (for a grid-tie application). The prototype is based on fully planar magnetic, Si MOSFETs, Si IGBTs and SiC diodes; efficiencies up to ~96.5% and ~97.8% were demonstrated depending on the converter operating point.

Pittini, Riccardo; Zhang, Zhe

2013-01-01

275

Esta tesis estudia el fenómeno del caos en las ecuaciones que modelan un convertidor buck con control PWM. Desde el punto de vista matemático, contribuye al estudio de los sistemas lineales a trozos tridimensionales, con émfasis en las perspectivas geométrica y de cálculo numérico. Se consiguen resultados analíticos pero, finalmente, deben emplearse métodos numéricos para calcular efectivamente las órbitas periódicas, bifurcaciones, variedades invariantes y cuencas de atracción. D...

Olivar, Gerard

1997-01-01

276

DC-DC Converters Using PID Controller and Pulse Width Modulation Technique

This paper presents a boost converter along with a flyback converter. The Zero Voltage Switching (ZVS) technique is used to achieve soft switching. A bidirectional boost converter is connected with an output module as a Parallel Input Serial Output configuration. The flyback converter with Voltage Doubler Rectifier (VDR) acts as an output module. This connection makes a bidirectional boost converter an active clamp circuit which is connected to the output side in order to extend the step up r...

Sudha, R.; Dhanasekaran, P. M.

2014-01-01

277

Development of TMS320F2810 DSP Based Bidirectional buck-boost Chopper

A DC - DC converter is an electronic circuit which converts a source of direct current (DC) from one voltage level to another. It is a class of power converter. One common application of DC - DC converters is DC motor control. The Buck - Boost Chopper is a type of DC - DC converter. They are static devices which are used to obtain variable DC voltage from the source of constant DC voltage. Besides the saving in power, Buck-Boost choppers offer greater efficiency, faster respon...

Mr. K.S. Chakradhar*1,; Ayesha Siddiqa, M.; Vandhana, T.

2014-01-01

278

Self-oscillating Galvanic Isolated Bidirectional Very High Frequency DC-DC Converter

DEFF Research Database (Denmark)

This paper describes a galvanic isolated bidirectional Very High Frequency (VHF = 30 MHz - 300MHz) ClassE converter. The reason for increasing the switching frequency is to minimize the passive components in the converter. To make the converter topology bidirectional the rectifier has to be synchronous. This increases the complexity of the gate drives, which in this paper is solved by using a self-oscillating gate drive. A bidirectional converter has been implemented and is described in this paper; the converter reaches efficiencies above 80% in forward conduction mode and 73.5% in reverse conduction mode. The designed converter operates at a switching frequency of 35.6 MHz, which is well within the VHF range. The same converter is also implemented with PCB embedded inductors to minimize cost and the physical volume of the total converter.

Pedersen, Jeppe Arnsdorf; Madsen, Mickey Pierre

2015-01-01

279

Two-output Class E Isolated dc-dc Converter at 5 MHz Switching Frequency

This paper presents a two output class-E isolated dcdc converter that regulates the output voltages at fixed switching frequency. The converter is simulated at operating frequency of 5 MHz. The converter output power is 40 W and the output voltages are 15 V and 5 V. All the switches operate at zero voltage switching (ZVS) conditions for the full load range. The circuit configuration is simple with small passive components which reduce the size of the converter. The circuit also has ...

Pavlovic, Zoran; Oliver Rami?rez, Jesu?s Angel; Alou Cervera, Pedro; Garci?a Sua?rez, Oscar; Prieto López, Roberto; Cobos Ma?rquez, Jose? Antonio

2010-01-01

280

Modular DC-DC converter system for energy harvesting with EAPs

Energy harvesting with EAPs requires an energy-efficient power electronics providing a bidirectional energy transfer and operating voltages of up to several kilovolts. A possibility to achieve a high energy-efficiency for high voltage conversion is the use of a modular converter system consisting of several bidirectional converter modules, which are connected in series on the converter output side and in parallel at the input side. Since each converter stage provides only a part of the overall converter output voltage, the converter module output voltages can effectively be reduced by choosing the number of cascaded converter modules appropriately. This allows the use of standard semiconductor switches with superior electrical characteristics compared to high voltage semiconductors, enabling a high energy-efficiency and smaller passive components. Since EAP devices exhibit a mainly capacitive behavior and a limitation of the operating current is required for electrode protection, the utilized converter structure/topology has to be operated as a controllable current source on the lowest control level, which is achieved by operating the converter modules of the modular converter system with a subordinate closed-looped current control scheme. In order to avoid voltage unbalances among the single converter modules, a method for voltage balancing is presented. For validation, experimental results of a realized bidirectional flyback converter prototype are presented and discussed.

Eitzen, L.; Graf, C.; Maas, J.

2013-04-01

281

Comparative Study on Paralleled vs. Scaled Dc-dc Converters in High Voltage Gain Applications

DEFF Research Database (Denmark)

Today power converters are present in many commercial, medical and industrial applications. A lot of them are high power and high current applications. In order to increase power handling capability several transistors or diodes are paralleled often. However such paralleling may lead to converter's performance degradation or switches quick failure. A parallel modular converter built of many paralleled modules may be an interesting alternative, while a modular converter provides well known advantages like scalability, improved reliability and lower cost. This paper investigates possibility of improving an efficiency by intelligent usage of a modular boost converter in a high voltage gain application.

Klimczak, Pawel; Munk-Nielsen, Stig

2008-01-01

282

Battery/Ultra-capacitor based electrical vehicles (EV) combine two energy sources with different voltage levels and current characteristics. This paper focuses on design and control of a multiple input DC/DC converter, to regulate output voltage from different inputs. The proposed multi-input converter is capable of bi-directional operation and is responsible for power diversification and optimization. A fixed switching frequency strategy is considered to control its operating modes. A portio...

Schaltz, Erik; Li, Zhihao; Onar, Omer; Khaligh, Alireza

2009-01-01

283

DC-DC Converters Using PID Controller and Pulse Width Modulation Technique

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a boost converter along with a flyback converter. The Zero Voltage Switching (ZVS technique is used to achieve soft switching. A bidirectional boost converter is connected with an output module as a Parallel Input Serial Output configuration. The flyback converter with Voltage Doubler Rectifier (VDR acts as an output module. This connection makes a bidirectional boost converter an active clamp circuit which is connected to the output side in order to extend the step up ratio. A converter with active clamp technique is used to recycle the leakage energy, to eliminate voltage spike due to coupled inductors and also to provide a mechanism to achieve ZVS. To overcome the efficiency degradation during light load due to load dependent soft switching of the ZVS, a control method using Pulse Width Modulation (PWM proportional to the load current is used.

R.Sudha

2014-01-01

284

Isolated DC-DC UPS based in a forward-forward converter analysis and design

This paper presents the analysis, design and simulation from a simple DC-UPS converter with integrated back-up and automatic transition. This converter makes automatic transition between the main AC and the battery when a failure occurs, and it delivers uninterrupted DC power to the load through two independent power sources of commercial input power and battery power. The converter has the following characteristics: automatic transition between the main and the battery, no additional control...

Garci?a Sua?rez, Oscar; Flores Oropeza, Luis Alejandro; Roma?n Loera, Alejandro; Esparza Gonza?lez, Mario S.

2008-01-01

285

A Two-stage DC-DC Converter for the Fuel Cell-Supercapacitor Hybrid System

A wide input range multi-stage converter is proposed with the fuel cells and supercapacitors as a hybrid system. The front-end two-phase boost converter is used to optimize the output power and to reduce the current ripple of fuel cells. The supercapacitor power module is connected by push-pull-forward half bridge (PPFHB) converter with coupled inductors in the second stage to handle the slow transient response of the fuel cells and realize the bidirectional power flow ...

Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

2009-01-01

286

Isolated DC-DC UPS Based in a Fly back Converter Analysis and Design

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the analysis, design andsimulation from a simple DC-UPS converter with integratedback-up and automatic transition. This converter makesautomatic transition between the main AC and the battery when afailure occurs, and it delivers uninterrupted DC power to the loadthrough two independent power sources of commercial inputpower and battery power. The converter has the followingcharacteristics: automatic transition between the main and thebattery, no additional control to detect failure in the main, singlestructure, galvanic isolation, multi output voltages capability andonly one switch control for two operation modes normal andback-up. The analysis, design, simulation and experimentalresults for this converter are presented.

Prof. Raju Bhabhor

2013-09-01

287

Design and Implementation of Power Flow Control for a novel Dual Input DC-DC Converter

DEFF Research Database (Denmark)

In this paper a control strategy for controlling the power flow from input voltage sources of a novel dual-input dcdc converter to the load is introduced. The converter can be used in renewable energy applications with two independent power sources. Firstly, the operation principle of the converter is outlined; then the control method for adjusting power sharing is proposed. In the next step, the controller is implemented in an FPGA, and then a 350W dual input converter is built to verify operation of the proposed control strategy. The experimental results show the excellent ability of the controller to control the power flow in the converter. The implemented controller in FPGA is low cost and simple. The complete system can be practically used in power management for renewable energy sources.

Taeed, Fazel; Ouyang, Ziwei

2014-01-01

288

DEFF Research Database (Denmark)

Electrical power system in future uninterruptible power supply (UPS) or electrical vehicle (EV) may employ hybrid energy sources, such as fuel cells and super-capacitors. It will be necessary to efficiently draw the energy from these two sources as well as recharge the energy storage elements by the DC bus. In this paper, a bidirectional isolated DC-DC converter controlled by phase-shift and duty cycle for the fuel cell hybrid energy system is analyzed and designed. The proposed topology minimizes the number of switches and their associated gate driver components by using two high frequency transformers which combine a half-bridge circuit and a full-bridge circuit together on the primary side. The voltage doubler circuit is employed on the secondary side. The current-fed input can limit the input current ripple that is favorable for fuel cells. The parasitic capacitance of the switches is used for zero voltage switching (ZVS). Moreover, a phase-shift and duty cycle modulation method is utilized to control thebidirectional power flow flexibly and it also makes the converter operate under a quasi-optimal condition over a wide input voltage range. This paper describes the operation principle of the proposed converter, the ZVS conditions and the quasi-optimal design in depth. The design guidelines and considerations about the transformers and other key components are given. Finally, a 1- kW 30~50-V-input 400-V-output laboratory prototype operating at 100 kHz switching frequency is built and tested to verify the effectiveness of the presented converter.

Zhang, Zhe; Ouyang, Ziwei

2012-01-01

289

High efficiency isolated DC/DC converter inherently optimized for fuel cell applications

DEFF Research Database (Denmark)

The isolated full-bridge boost converter has been suggested as the best choice for fuel cell applications. Comparisons have been carried out in the literature using both stress factors and experimental verified designs to determine the optimal converter. Never the less, this paper suggests a different topology not previous used for fuel cell applications with some clear advantages. Taking into account the I-V characteristics of the fuel cell only emphasized the performance of the proposed converter and reveals its self as an optimal candidate for the fuel cell application.

Petersen, Lars Press; Jensen, Lasse Crone

2013-01-01

290

Modeling and control of isolated full bridge boost DC-DC converter implemented in FPGA

DEFF Research Database (Denmark)

In this paper an isolated full bridge boost converter (IFBC) firstly is modeled. In the modeling part, a small signal equivalent of the converter is developed. From the small signal model, the converter transfer function is derived. Based on the obtained transfer function, challenges of controller design are discussed. In the next step a digital PI controller is designed and implemented in a FPGA to control the output voltage. Using the injection transformer method the open loop transfer function in closed loop is measured and modeling results are verified by experimental results. © 2013 IEEE.

Taeed, Fazel; Nymand, M.

2013-01-01

291

Directory of Open Access Journals (Sweden)

Full Text Available The time varying, nonlinear nature of the power switches and several other sources of nonlinearities in DC-DC Converters deviates its performance from the theoretical prediction of stability. The switching nature necessitates a study of the stability and their periodic orbit rather than the equilibrium point. The closed loopoperation exhibits several types of nonlinear phenomena including bifurcation, chaos and quasi-periodicity. This paper is oriented with the analysis of such nonlinear phenomena in buck converter and attempts to coin a new strategy that can control chaos and significantly extend the parameter range for nominal period-I operation, in its mission to enhance the operating range of the converter.

Dr. S. R. PARANJOTHI,

2011-01-01

292

Energy Technology Data Exchange (ETDEWEB)

Plug-in hybrid electric vehicles (PHEVs) will play a vital role in future sustainable transportation systems due to their potential in terms of energy security, decreased environmental impact, improved fuel economy, and better performance. Moreover, new regulations have been established to improve the collective gas mileage, cut greenhouse gas emissions, and reduce dependence on foreign oil. This paper primarily focuses on two major thrust areas of PHEVs. First, it introduces a grid-friendly bidirectional alternating current/direct current ac/dc dc/ac rectifier/inverter for facilitating vehicle-to-grid (V2G) integration of PHEVs. Second, it presents an integrated bidirectional noninverted buck boost converter that interfaces the energy storage device of the PHEV to the dc link in both grid-connected and driving modes. The proposed bidirectional converter has minimal grid-level disruptions in terms of power factor and total harmonic distortion, with less switching noise. The integrated bidirectional dc/dc converter assists the grid interface converter to track the charge/discharge power of the PHEV battery. In addition, while driving, the dc/dc converter provides a regulated dc link voltage to the motor drive and captures the braking energy during regenerative braking.

Onar, Omer C [ORNL

2012-01-01

293

A study of DC-DC converters with MCT's for arcjet power supplies

Many arcjet DC power supplies use PWM full bridge converters with large arrays of parallel FET's. This report investigates an alternative supply using a variable frequency series resonant converter with small arrays of parallel MCT's (metal oxide semiconductor controlled thyristors). The reasons for this approach are to: increase reliability by reducing the number of switching devices; and decrease the surface mounting area of the switching arrays. The variable frequency series resonant approach is used because the relatively slow switching speed of the MCT precludes the use of PWM. The 10 kW converter operated satisfactorily with an efficiency of over 91 percent. Test results indicate this efficiency could be increased further by additional optimization of the series resonant inductor.

Stuart, Thomas A.

1994-01-01

294

An Effective High Step-Up Interleaved DC-DC Converter Photovoltaic Grid Connection System

Within the photovoltaic (PV) power generation systems in the market, the ac PV module has shown obvious growth. However, a high voltage gain converter is concentrate for the module’s grid connection with dc-ac inverter. This paper proposed a converter that employs a floating active switch to isolate energy from the PV panel when the ac module is OFF; this particular design protects installers and users from electrical hazards. Without extreme duty ratios and numerous turns-ratio of a couple...

G. Lakpathi,; S. ManoharReddy,; K. Lakshmi Ganesh,; G. Satyanarayana,

2013-01-01

295

This paper presents an experimental discussion on a 6-kW, full-bridge, zero-voltage switching bidirectional isolated dc/dc converter for a 53.2-V, 2-kWh Li-ion battery energy storage system. The combination of high-frequency switching devices, 600-V/200-A IGBTs and 100-V/500-A MOSFETs with a high-frequency transformer reduces the weight and physical size of the bidirectional isolated dc/dc converter. The dc voltage on the high-voltage side of the converter is controlled in a range of 300V to 355V as the battery voltage on the low-voltage side varies from 50V to 59V. Experimental verification of bidirectional power flow into (battery charging) or out of (battery discharging) the Li-ion battery bank is also presented. The maximal efficiency of the dc/dc converter is measured to be 98.1% during charging and 98.2% during discharging, excluding the gate drive loss and control circuit loss.

Abe, Takahiro; Tan, Nadia Mei Lin; Akagi, Hirofumi

296

DEFF Research Database (Denmark)

Abstract-In this paper, an extended run time DC UPS system structure with fuel cell and supercapacitor is investigated. A wide input range bi-directional dc-dc converter is described along with the phase-shift modulation scheme and phase-shift with duty cycle control, in different modes. The delivered power and peak current are analyzed and calculated. The key parameters of the bi-directional dc-dc converter, the relationships between the input voltage, phase-shift angle, ratio of the transformer and leakage inductance are analyzed and optimized. Build the system mathematic model and a novel input voltage combined with load current feedback using PI controller with anti-windup scheme to realize closed-loop control of the whole system, and verify the feasibility of the control scheme proposed by simulation. A 1kW prototype controlled by TMS320F2808 DSP is implemented and tested. Experimental results show the validity of design.

Zhang, Zhe; Thomsen, Ole Cornelius

2009-01-01

297

Directory of Open Access Journals (Sweden)

Full Text Available In recent years, power demand of industrial applications has increased significantly reaching some megawatts. The use of multilevel converters for applications of medium and high powers is proposed as a solution to drawback semiconductor technology. A multilevel converter not only achieves high power ratings, but also enables the use of renewable energy sources. Renewable energy sources such as photovoltaic can be easily interfaced to a multilevel converter system for a high power application. This paper presents the simulation study in Matlab/Simulink of a grid connected photovoltaic three phase Neutral Point Clamped (NPC inverter with DC/DC boost converter for constant and variable solar radiation.

Mechouma Rabiaa

2014-01-01

298

Energy Technology Data Exchange (ETDEWEB)

This work describes the bifurcational behavior of a modular peak current-mode controlled DC-DC boost converter with multi bifurcation parameters. The parallel-input/parallel-output converter consists of two identical boost circuits and operates in the continuous-current conduction mode (CCM). A nonlinear mapping in closed form is derived and bifurcation diagrams are generated using MATLAB. A comparison is made between the modular converter diagrams with those of the single boost converter. The effect of introducing mutual coupling between the inductors of the constituent modules is also addressed. Results are verified using the circuit analysis package PSPICE.

Natsheh, Ammar N. [Faculty of Engineering, Al-Ahliyya Amman University, Post Code 19328 Amman (Jordan); Nazzal, Jamal M. [Faculty of Engineering, Al-Ahliyya Amman University, Post Code 19328 Amman (Jordan)]. E-mail: jnazzal@ammanu.edu.jo

2007-08-15

299

The 25 kW resonant dc/dc power converter

The feasibility of processing 25-kW of power with a single, transistorized, series resonant converter stage was demonstrated by the successful design, development, fabrication, and testing of such a device which employs four Westinghouse D7ST transistors in a full-bridge configuration and operates from a 250-to-350 Vdc input bus. The unit has an overall worst-case efficiency of 93.5% at its full rated output of 1000 V and 25 A dc. A solid-state dc input circuit breaker and output-transient-current limiters are included in and integrated into the design. Full circuit details of the converter are presented along with the test data.

Robson, R. R.

1983-09-01

300

High-Efficiency Self-Adjusting Switched Capacitor DC-DC Converter with Binary Resolution

Switched-Capacitor Converters (SCC) suffer from a fundamental power loss deficiency which make their use in some applications prohibitive. The power loss is due to the inherent energy dissipation when SCC operate between or outside their output target voltages. This drawback was alleviated in this work by developing two new classes of SCC providing binary and arbitrary resolution of closely spaced target voltages. Special attention is paid to SCC topologies of binary resolut...

Kushnerov, Alexander

2010-01-01

301

In this work a step by step planar transformer design proccdare for Flybock switch-mode DC-DC converter application is presented. This transformer has a maximum dimention of 2cm x 2cm x 0.4cm aiming to achieve an efficiency of 99% at an operating frequency of 500kHz. This planar transformer is designed specially for thick film technology development.

Arshak, Khalil; Almukhtar, Basil

2000-01-01

302

Soft Switching Full-Bridge PWM DC/DC Converter Using Secondary Snubber

Directory of Open Access Journals (Sweden)

Full Text Available A novel full-bridge PWM DC/DCconverter with controlled secondary side rectifier usingsecondary snubber is presented in this paper.Limitation of the circulating current as well as softswitching for all power switches of the inverter isachieved for full load range from no-load to shortcircuit by using controlled rectifier and snubber on thesecondary side. Phase shift PWM control strategy isused for the converter. The principle of operation isexplained and analyzed and the experimental resultson a 1kW, 50 kHz laboratory model of the converterare presented.

Jaroslav Dudrik

2009-05-01

303

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Este artículo presenta una revisión de la literatura sobre sistemas eólicos de micro generación. La revisión analiza cuatro tópicos: la topología del sistema, su modelado, el diseño de los convertidores de potencia y el control de los mismos. Finalmente, la revisión resalta los problemas de investig [...] ación abiertos, así como las oportunidades para mejorar soluciones comúnmente utilizadas Abstract in english This paper presents a literature review analyzing four topics concerning wind systems for micro-generation: system topologies, system modeling, power converters design, and power converter controllers. The review also reveals the open research problems in the literature, and the opportunities to imp [...] rove commonly adopted solutions

Carlos Alejandro, Ramírez; Andrés Julián, Saavedra-Montes; Carlos Andrés, Ramos-Paja.

2014-01-01

304

Many Embedded Systems are indeed Software Based Control Systems (SBCSs), that is control systems whose controller consists of control software running on a microcontroller device. This motivates investigation on Formal Model Based Design approaches for automatic synthesis of SBCS control software. In previous works we presented an algorithm, along with a tool QKS implementing it, that from a formal model (as a Discrete Time Linear Hybrid System, DTLHS) of the controlled syst...

Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico

2011-01-01

305

This paper presents an advanced power converter employs a sinusoidal voltage absolute value tracking buck-boost DC-DC converter in the first power processing stage and a polarity changing full-bridge inverter in the second stage. The proposed power conversion system has the capability of delivering sinusoidal output and input current with unity power factor and good output voltage regulation. Consequently, the complete voltage regulator system, which is mainly suitable for new energy generation systems as well as energy storage systems, can be constructed compactly and inexpensively without DC link electrolytic capacitor. Also, the paper presents an auxiliary passive resonant circuit for soft switching operation. Simulation results using PSIM software are presented to verify the operation principles and feasibility of the proposed power conversion system.

Ahmed, Nabil A.

2011-06-01

306

A prototype of a fuel cell PEM emulator based on a buck converter

International Nuclear Information System (INIS)

After a brief introduction about fuel cell systems, and their modelling, this paper proposes a possible solution to emulate a proton exchange membrane fuel cell (PEM-FC) system by using a DC-DC buck converter. The fuel cell system, including all its auxiliaries and related control systems, is emulated by a buck converter realized experimentally and controlled in the DSPACE environment. The realization of the buck converter allows the behaviour of any fuel cells to be easily emulated since only the modification of the control law of the switch is necessary. The proposed emulator can be applied easily to other fuel cell systems if the polarization curve has the same current rate and maximum power. In this way it is possible to utilize the converter and perform the necessary tests to optimize a fuel cell system by avoiding the waste of hydrogen and the purchase of cells as well as any cell damage. With regard to current other types of emulators, the one presented here has the following characteristics: (1) all the auxiliaries of the system have been considered, each including its own control system, as in a real FCS, (2) the converter is a classical buck converter with a free-wheeling diode and is designed to have a high bandwidth and to be practically always in conduction mode (discontinuous mode appears only at very low currents) (3) the voltage control is made by a space-state controller, able to fix properly the closed loop poles of the system, thus guaranteeing the oles of the system, thus guaranteeing the desired bandwidth of the control system and (4) it can be used in laboratory as a stand-alone low-cost system for design and experimental purposes.

307

A prototype of a fuel cell PEM emulator based on a buck converter

Energy Technology Data Exchange (ETDEWEB)

After a brief introduction about fuel cell systems, and their modelling, this paper proposes a possible solution to emulate a proton exchange membrane fuel cell (PEM-FC) system by using a DC-DC buck converter. The fuel cell system, including all its auxiliaries and related control systems, is emulated by a buck converter realized experimentally and controlled in the DSPACE environment. The realization of the buck converter allows the behaviour of any fuel cells to be easily emulated since only the modification of the control law of the switch is necessary. The proposed emulator can be applied easily to other fuel cell systems if the polarization curve has the same current rate and maximum power. In this way it is possible to utilize the converter and perform the necessary tests to optimize a fuel cell system by avoiding the waste of hydrogen and the purchase of cells as well as any cell damage. With regard to current other types of emulators, the one presented here has the following characteristics: (1) all the auxiliaries of the system have been considered, each including its own control system, as in a real FCS, (2) the converter is a classical buck converter with a free-wheeling diode and is designed to have a high bandwidth and to be practically always in conduction mode (discontinuous mode appears only at very low currents) (3) the voltage control is made by a space-state controller, able to fix properly the closed loop poles of the system, thus guaranteeing the desired bandwidth of the control system and (4) it can be used in laboratory as a stand-alone low-cost system for design and experimental purposes. (author)

Marsala, Giuseppe; Cirrincione, Maurizio; Miraoui, Abdellatif [FClab- SET, Universite de Technologie de Belfort-Montbeliard (UTBM), Belfort (France); Pucci, Marcello; Vitale, Gianpaolo [ISSIA-CNR (Institute on Intelligent Systems for the Automation), Via Dante, 12, Palermo (Italy)

2009-10-15

308

Directory of Open Access Journals (Sweden)

Full Text Available This paper analyzes and simulates the Li-ion battery charging process for a solar powered battery management system. The battery is charged using a non-inverting synchronous buck-boost DC/DC power converter. The system operates in buck, buck-boost, or boost mode, according to the supply voltage conditions from the solar panels. Rapid changes in atmospheric conditions or sunlight incident angle cause supply voltage variations. This study develops an electrochemical-based equivalent circuit model for a Li-ion battery. A dynamic model for the battery charging process is then constructed based on the Li-ion battery electrochemical model and the buck-boost power converter dynamic model. The battery charging process forms a system with multiple interconnections. Characteristics, including battery charging system stability margins for each individual operating mode, are analyzed and discussed. Because of supply voltage variation, the system can switch between buck, buck-boost, and boost modes. The system is modeled as a Markov jump system to evaluate the mean square stability of the system. The MATLAB based Simulink piecewise linear electric circuit simulation tool is used to verify the battery charging model.

Chien-Wei Ma

2013-03-01

309

Scientific Electronic Library Online (English)

Full Text Available Neste artigo analisa-se e desenha-se um conversor multinível em topologia tipo escada para una aplicação de alta voltagem (3000 V). Este conversor é comparado com outra estrutura conhecida chamada flying capacitors e mostra sua simplicidade na implementação e no controle. Adicionalmente, analisam as [...] quedas de voltagem a topologia tipo escada em função do número de celular e da corrente de carga. Por outro lado, implementa-se o conversor, que alcança satisfatoriamente 3000 V 100 mA e com os resultados obtidos validam-se as análises teóricas. O conversor é testado com dois tipos diferentes de condensadores e, assim, determina-se qual deles tem o melhor desempenho. Abstract in spanish En este artículo se analiza y se diseña un convertidor multinivel en topología escalera para una aplicación de alto voltaje (3.000 V). Este convertidor se compara con otra estructura conocida llamada flying capacitors y muestra su sencillez en la implementación y en el control. Adicionalmente, se an [...] alizan las caídas de voltaje de la topología escalera en función del número de celdas y de la corriente de carga. Por otro lado, se implementa el convertidor, que alcanza satisfactoriamente 3000 V 100 mA y con los resultados obtenidos se validan los análisis teóricos. El convertidor se prueba con dos tipos diferentes de condensadores y, así, se determina cuál de ellos tiene el mejor desempeño. Abstract in english This article analyzes and designs a ladder multilevel converter topology for a high voltage application (3000 V). This converter is compared to other well-known structures called Flying Capacitors showing its simplicity for implementation and control. In addition, an analysis of the voltage drop of [...] the ladder topology is carried out as a function of the number of cells and of the load current. Furthermore, the converter is implemented and successfully achieves 3000 V 100 mA. The theoretical analysis is validated by the results. The converter is tested with two different types of capacitors in order to determine which one offers a better performance.

Andrés Mauricio, López-Cañón; Rafael Fernando, Diez-Medina; Gabriel, Perilla-Galindo; Diego Alejandro, Patiño-Guevara.

2012-06-01

310

DEFF Research Database (Denmark)

Battery/Ultra-capacitor based electrical vehicles (EV) combine two energy sources with different voltage levels and current characteristics. This paper focuses on design and control of a multiple input DC/DC converter, to regulate output voltage from different inputs. The proposed multi-input converter is capable of bi-directional operation and is responsible for power diversification and optimization. A fixed switching frequency strategy is considered to control its operating modes. A portion of New York City Cycle that includes these operation modes is used to perform the analyses.

Schaltz, Erik; Li, Zhihao

2009-01-01

311

International Nuclear Information System (INIS)

In this article, we aim at optimizing an innovative tandem structure based on polymorphous and microcrystalline silicon for the top and bottom elementary cells, respectively, combined with an original DC-DC converter. The studied tandem structure is composed of two cells, each being connected to its own separate electrodes making the structure electrically decoupled but optically coupled. In those conditions, the constraint of current matching usually needed in the classical micromorph structures is avoided. As a result, the robustness against the current variations is enhanced and the efficiency of the structure is improved. Since the top cell plays the main role in the determination of the transmitted part of the incoming flux to the bottom cell, the thickness of the intrinsic layer of the polymorphous cell is tuned so that the output power of the global structure becomes maximal. To implement the electric decoupling of two sub cells, the studied structure needs two static converters. In order to minimize the converters bulk, we design an innovative output electric architecture and its optimized related control signals. -- Highlights: ? We optimized an innovative silicon thin film 4-wires tandem solar structure. ? The sub-cells are made of polymorphous and microcrystalline silicon. ? Electric decoupling of solar sub-cells leads to avoid current matching constraint. Robustness against current variations is enhanced and the efficiency is improved. The studied structure is combined with an original DC-DC converter. ? This systemic approach improves efficiency and reduces cost of the global structure.

312

Improved Dynamic Response of Buck Converter using Fuzzy Controller

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents comparative performance of Buck Converter in both open as well as closed loop. With the help state equations Mathematical Model of Buck Converter is designed in MATLAB/SIMULINK. The obtained output response of open loop Buck Converter is sluggish, not optimum and consists of peak overshoots. PI Controller is used in closed loop model of Buck Converter. Output Voltage is compared with a reference signal, which then is processed through a controller (PI/Fuzzy. The obtained signal is superimposed with a carrier signal and given to switching device used. To further optimize the performance of Buck Converter and eliminate the peak overshoot present in output response, Fuzzy controller is used. Here Suguno type Fuzzy is used.

Nagulapati Kiran

2014-03-01

313

This paper describes the design, construction, and testing of a 320-V, 12-F EDLC energy storage bank equipped with a bidirectional isolated dc-dc converter. A simple voltage-balancing circuit is proposed, which combines a center-tapped high-frequency transformer and the EDLC bank consisting of two 160-V, 24-F EDLC sub-banks connected in series. Experimental results including charging/discharging and self-starting waveforms are shown to verify the effectiveness of the proposed voltage-balancing circuit. The power loss in the voltage-balancing circuit is verified to be negligibly small during the charging/discharging operation.

Kobayashi, Atsushi; Tan, Nadia Mei Lin; Inoue, Shigenori; Akagi, Hirofumi

314

DC transformer for DC/DC connection in HVDC network

This paper presents the modeling and control of a multilevel DC/DC bidirectional converter suitable for medium voltage and power applications, with a special interest in wind-power applications. The proposed multilevel topology has a modular structure constituted by base DC/DC converter cells. The multilevel converter is consequently based on Dual Active Bridge (DAB). The overall control of the DC/DC converter is achieved by using a nonlinear control based in Lyapunov theory.

Carrizosa, Jimenez; Benchaib, Abdelkrim; Alou, Pedro; Damm, Gilney

2013-01-01

315

DEFF Research Database (Denmark)

This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high-frequency transformer; this structure minimizes the number of the switching transistors and their associate gate driver components. With phase-shift control strategy, all the switches are operated under zero-voltage switching (ZVS) condition. Furthermore, in order to optimize the converter performance and increase efficiency, optimal design methods and criteria are investigated, including coupled inductors design, bidirectional power flow analysis, harmonics analysis, and ZVS range extension. Based on all the optimal parameters, higher efficiency can be achieved. Finally, prototypes are built in laboratory controlled by digital signal processor for comparison purpose. Detailed test results verify the theoretical analysis and demonstrate the validity of optimization design method.

Zhang, Zhe; Thomsen, Ole Cornelius

2012-01-01

316

International Nuclear Information System (INIS)

A novel on-chip frequency compensation circuit for a voltage-mode control DC/DC converter is presented. By employing an RC network in the two signal paths of an operational transconductance amplifier (OTA), the proposed circuit generates two zeros to realize high closed-loop stability. Meanwhile, full on-chip integration is also achieved due to its simple structure. Hence, the number of off-chip components and the board space is greatly reduced. The structure of the dual signal path OTA is also optimized to help get a better transition response. Implemented in a 0.5 ?m CMOS process, the voltage mode control DC/DC converter with the proposed frequency compensation circuit exhibits good stability. The test results show that both load and line regulations are less than 0.3%, and the output voltage can be recovered within 15 ?s for a 400 mA load step. Moreover, the compensation components area is less than 2% of the die's area and the board space is also reduced by 11%. The efficiency of the whole chip can be up to 95%. (semiconductor integrated circuits)

317

Energy Technology Data Exchange (ETDEWEB)

Among innovative conversion systems for alternative energy, Fuel Cells (FCs) are ideal in applications as distributed power generation or automotive. The connection of FCs to domestic or industrial loads requires a DC/AC converter also acting as a energy buffer to match the different dynamics of FCs and loads. In the last years, a new type of electrolytic capacitors called Super- Capacitors (SCs), has been designed using double layers technology. Such components are able to store more energy than electrolytic capacitors maintaining the capability to swap it at high power levels. Firstly, different solution used to connect SCs to a FC based conversion system are considered. Then, a comparison of bi-directional DC/DC converters designed to manage SCs energy is performed. Finally, the converter design and a laboratory prototype of the adopted solution are reported. (authors)

Cacciato, M.; Giulii Capponi, F. [Rome Univ., ' La Sapienza' , Dept. of Electrical Engineering (Italy)

2004-07-01

318

Energy Technology Data Exchange (ETDEWEB)

This work belongs to the European Barmint project which final goal is the realization of a micro-system, implanted in the human body, and devoted to the regulation of the blood pressure of patients. The aim of this thesis is the realization of the miniaturized power supply of this micro-system. The different approaches allowing to reach the required voltage levels from the 3.5 V initial level are analysed first. A solution based on the integration of DC-DC converters with their control loop has been retained. A control loop based on a single-cycle control principle and completed with a technique of control of the maximum current has been applied for the first time to a boost converter in order to eliminate the disturbances coming from the output of the photovoltaic cells. A first prototype with a single converter and with such a control loop has been successfully built and validated. Then a full system has been built which comprises: a DC-DC converter with its control loop for the 5 V-130 mA power supply and two parallel converters with their control loop for the 60 V output supply. This loop comprises an energy saving circuit which switches on the converters only when required by the health situation of the patient. It includes also a charge pump circuit which allows to supply the different 5 V control loop blocks using the 3.5 V input voltage. The entire system represents a 17.5 mm{sup 2} silicon surface. The second part of this work concerns the integration of a coil on a silicon surface. Iron/nickel alloy deposits on silicon substrates have been obtained and characterized. (J.S.)

Senouci, N.

1998-07-01

319

A DC-DC conversion powering scheme for the CMS Phase-1 pixel upgrade

International Nuclear Information System (INIS)

The CMS pixel detector was designed for a nominal instantaneous LHC luminosity of 1?1034 cm?2s?1. During Phase-1 of the LHC upgrade, the instantaneous luminosity will be increased to about twice this value. To preserve the excellent performance of the pixel detector despite the increase in particle rates and track densities, the CMS Collaboration foresees the exchange of its pixel detector in the shutdown 2016/2017. The new pixel detector will be improved in many respects, and will comprise twice the number of readout channels. A powering scheme based on DC-DC conversion will be adopted, which will enable the provision of the required power with the present cable plant. The powering scheme of the CMS pixel detector will be described, and the performance of prototype DC-DC buck converters will be presented, including power efficiency, system tests with DC-DC converters and pixel modules, thermal management, reliability at low temperature, and studies of potential frequency locking between DC-DC converters.

320

A DC-DC conversion powering scheme for the CMS Phase-1 pixel upgrade

The CMS pixel detector was designed for a nominal instantaneous LHC luminosity of 1?1034 cm-2s-1. During Phase-1 of the LHC upgrade, the instantaneous luminosity will be increased to about twice this value. To preserve the excellent performance of the pixel detector despite the increase in particle rates and track densities, the CMS Collaboration foresees the exchange of its pixel detector in the shutdown 2016/2017. The new pixel detector will be improved in many respects, and will comprise twice the number of readout channels. A powering scheme based on DC-DC conversion will be adopted, which will enable the provision of the required power with the present cable plant. The powering scheme of the CMS pixel detector will be described, and the performance of prototype DC-DC buck converters will be presented, including power efficiency, system tests with DC-DC converters and pixel modules, thermal management, reliability at low temperature, and studies of potential frequency locking between DC-DC converters.

Feld, L.; Fleck, M.; Friedrichs, M.; Hensch, R.; Karpinski, W.; Klein, K.; Sammet, J.; Wlochal, M.

2013-02-01

321

Directory of Open Access Journals (Sweden)

Full Text Available The current paper deals with a multi-objective design approach of power converters applied to a DC-DC buck structure. This approch consists on optimizing a preselected power architecture by minimizing a multi-objective function (volume and time response under multi-physic constraints (efficiency, thermal, electromagnetic compatibility and control. This multi-objective optimization allows evaluating the impact of the control aspect on the converter design by considering the control criteria with the same importance as the conventional constraints. The obtained results confirm the influence of the control on the converter design parameters. They help the designer to choose suitable operating points depending on the desired performances in terms of volume and time response while respecting efficiency, junction temperatures and electromagnetic compatibility constraints.

Cherif Larouci

2012-06-01

322

Two-Phase Interleaved Buck Converter with a new Digital Self-Oscillating Modulkator

DEFF Research Database (Denmark)

This paper presents a new Digital Self-Oscillating Modulator (DiSOM) for DC/DC converters. The DiSOM modulator alllows the digital control algorithm to sample the output voltage at a sampling frequency higher than the converter switching frequency. This enables higher control loop bandwidth than for traditional digital PWM modulators given a certain switching frequency. A synchronised version of the DiSOM modulator is derived for interleaved converters. A prototype interleaved Buck converter for Point of Load applications has been designed and built to test the performance of DiSOM modulator. The DiSOM modulator and a digital control algorithm have been implemented in an FPGA. Experimental results show that the converter has a very fast transient response when a loadstep is applied to the output. For a loadstep of 50% of nominal output current the output voltage overshoot is less than 2.5% of the nominal output voltage and the settling time is just 8 switching periods.

Jakobsen, Lars TØnnes; Andersen, Michael Andreas E.

2007-01-01

323

Bifurcation Control of Current-Mode Buck Converter via TDFC

Considering the TDFC controlled current-mode Buck converter featuring periodicity we propose a Fourier-decomposition based method for the bifurcation analysis of this system, hence the theoretical range of control gain of TDFC is determined. In addition, the power-stage experiment circuit is built and the control part is realized in a digital controller. The experimental results show that either bifurcation or chaos in the current-mode Buck converter can be controlled into the expectant period-1 orbit rapidly.

Lu, Wei-Guo; Xu, Ping-Ye; Zhou, Luo-Wei; Luo, Quan-Ming

2010-03-01

324

Research on a Novel Soft-Switching Buck Converter

Based on classical zero voltage transition buck pwm converter, an ideal buck converter with pwm-controlled soft-switching circuit is proposed. The proposed auxiliary circuit allows the main switch to operate with zero-voltage switching. Besides, all of the semiconductor devices operate under soft-switching conditions. Thus, losses were reduced. It was analyzed in detail to demonstrate the operating principle of the novel circuit. Finally, simulation results are given analysis and the simulati...

Peng Ge; Ben Niu; Yuanbin Li

2013-01-01

325

Two phase interleaved buck converter for driving high power LEDs

DEFF Research Database (Denmark)

The goal of this paper is to evaluate an interleaved buck topology for driving high current light-emitting diodes. Low output capacitor value allows the use of non-electrolytic capacitors extending the lifetime of the converter. Converter is operated as a constant, regulated current source which increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can be operated close to the 50% duty cycle, where the ripple attenuation is the highest.

Beczkowski, Szymon; Munk-Nielsen, Stig

2011-01-01

326

Methods of Battery Charging with Buck Converter Using Soft-Switching Techniques

Directory of Open Access Journals (Sweden)

Full Text Available This paper is a detailed study on methods of battery charging with Buck Resonant converter using soft switching techniques like ZVS and ZCS. This study also presents the circuit configuration with the least components to realize a highly efficient solar energy battery charger with a zero-voltage and zero current switching resonant converter. The high-frequency resonant converter has numerous well-known advantages over the traditional hard-switching converters. The most important advantage is that it offers a lower switching loss and a higher power density. Additionally, the soft switching current waveform characterizes a lower electromagnetic interference (EMI. The operating principles and design procedure of the proposed charger with both zero voltage and zero current are thoroughly analyzed. The optimal values of the resonant components are computed by applying the characteristic curve and electric functions derived from the circuit configuration. Finally, a simulation model is implemented for charger circuit designed for a 12-V 4-Ah lead acid battery using zero voltage and zero current switching and MATLAB/SIMULINK software is used as the simulation tool. The proposed dc?dc battery charger has a straightforward structure, low cost, easy control, and high efficiency. Satisfactory performance is obtained from the experimental results.

S. Abinaya

2011-12-01

327

This paper describes a bi-directional isolated dc/dc converter considered as a core circuit of 3.3-kV/6.6-kV high-power-density power conversion systems in the next generation. The dc/dc converter is intended to use power switching devices based on SiC and/or GaN, which will be available on the market in the near future. A 350-V, 10-kW and 20kHz dc/dc converter is designed, constructed and tested in this paper. It consists of two single-phase full-bridge converters with the latest trench-gate Si-IGBTs and a 20-kHz transformer with a nano-crystalline soft-magnetic material core and litz wires. The transformer plays an essential role in achieving galvanic isolation between the two full-bridge converters. The overall efficiency from the dc-input to dc-output terminals is accurately measured to be as high as 97%, excluding gate drive circuit and control circuit losses from the whole loss. Moreover, loss analysis is carried out to estimate effectiveness in using SiC-based power switching devices. The loss analysis clarifies that the use of SiC-based power devices may bring a significant reduction in conducting and switching losses to the dc/dc converter. As a result, the overall efficiency may reach 99% or higher.

Inoue, Shigenori; Akagi, Hirofumi

328

Electrochemical oxidation of tannery effluent was carried out in batch, batch recirculation and continuous reactor configurations under different conditions using a battery-integrated DC-DC converter and solar PV power supply. The effect of current density, electrolysis time and fluid flow rate on chemical oxygen demand (COD) removal and energy consumption has been evaluated. The results of batch reactor show that a COD reduction of 80.85% to 96.67% could be obtained. The results showed that after 7 h of operation at a current density of 2.5 A dm(-2) and flow rate of 100 L h(-1) in batch recirculation reactor, the removal of COD is 82.14% and the specific energy consumption was found to be 5.871 kWh (kg COD)(-1) for tannery effluent. In addition, the performance of single pass flow reactors (single and multiple reactors) system of various configurations are analyzed. PMID:24844896

Iyappan, K; Basha, C Ahmed; Saravanathamizhan, R; Vedaraman, N; Tahiyah Nou Shene, C A; Begum, S Nathira

2014-01-01

329

DEFF Research Database (Denmark)

This paper presents a new zero-voltage-switching (ZVS) isolated dc-dc converter which combines a boost halfbridge (BHB) cell and a full-bridge (FB) cell, so that two different type of power sources, i.e. both current-fed and voltage-fed, can be coupled effectively by the proposed converter for various applications, such as fuel cell and super-capacitor hybrid energy system. By fully using two high frequency transformers and a shared leg of switches, number of the power devices and associated gate driver circuits can be reduced. With phase-shift control, the converter can achieve ZVS turn-on of active switches and zero-current switching (ZCS) turn-off of diodes. In this paper, derivation, analysis and design of the proposed converter are presented. Finally, a 25~50 V input, 300~400 V output prototype with a 600 W nominal power rating is built up and tested to demonstrate the effectiveness of the proposed converter topology.

Zhang, Zhe; Thomsen, Ole Cornelius

2013-01-01

330

DEFF Research Database (Denmark)

This paper presents an isolated dual-input DC-DC converter with a PWM plus phase-shift control for fuel cell hybrid energy systems. The power switches are controlled by phase shifted PWM signals with a variable duty cycle, and thus the two input voltages as well as the output voltage can be regulated effectively. By using the second input capacitor and the high side switches as an inherent active clamping circuit, zerovoltage switching (ZVS) for the power MOSFETs on the primary side, and zero-current switching (ZCS) for the diodes on the secondary side are achieved respectively to improve the performance of the proposed PWM converter. The principle of operation is analyzed and some design considerations are discussed. Simulation results using PLECS are given to verify the proposed analysis and design. An experimental converter prototype has been designed, constructed and tested in the laboratory to verify the validity of the theoretical analysis and also demonstrate the converter’s performance over wide variations in input voltage.

Zhang, Zhe; Andersen, Michael A. E.

2013-01-01

331

This paper presents a new circuit topology of full-bridge soft-switching PWM inverter linked DC-DC power converter composed of conventional full-bridge high frequency PWM inverter with high frequency transformer and an active quasi-resonant snubber consisting of an additional power switching device in series with DC busline and a lossless capacitor in parallel with DC busline. Under this proposed high frequency soft-switching PWM inverter linked DC-DC converter, four power switches in the full-bridge arms and DC busline series switch can achieve ZVS at turn-off commutation. By developing the advanced soft-switching PWM high frequency inverter type DC-DC converter, although the conduction power loss of DC busline series power switch increases a little, the total turn-off switching loss of full-bridge high frequency inverter power modules can be sufficiently lowered more and more in the higher frequency range of 60kHz. As a result, when the switching frequency of high frequency inverter power stage using IGBT power modules is designed so as to be more than about 10kHz, the more the switching frequency of inverter increases, the more this high frequency soft-switching DC-DC converter has remarkable advantage as for the power conversion efficiency as compared with the conventional hard-switching PWM inverter DC-DC converter. Its practical effectiveness of high power density and high performance is actually proved for TIG arc welding equipment in industry.

Morimoto, Keiki; Doi, Toshimitsu; Manabe, Haruhiko; Ahmed, Tarek; Hiraki, Eiji; Lee, Hyun-Woo; Nakaoka, Mutsuo

332

?uk-Buck Converter for Standalone Photovoltaic System

This paper presents MPPT converter for battery charger. The converter combines both ?uk and buck converters to extract the maximum power from the sun while supplying a controlled constant current/voltage to the battery. The topology uses two control signals instead of one control signal; one for tracking the maximum power point, another for charging the battery providing constant current/voltage to the battery. The advantage of this converter is to exploit the maximum power of the PV array a...

El Khateb, Ahmad H.; Nasrudin Abd Rahim; Jeyraj Selvaraj

2013-01-01

333

Bifurcation Control of Current-Mode Buck Converter via TDFC

International Nuclear Information System (INIS)

Considering the TDFC controlled current-mode Buck converter featuring periodicity we propose a Fourier-decomposition based method for the bifurcation analysis of this system, hence the theoretical range of control gain of TDFC is determined. In addition, the power-stage experiment circuit is built and the control part is realized in a digital controller. The experimental results show that either bifurcation or chaos in the current-mode Buck converter can be controlled into the expectant period-1 orbit rapidly. (general)

334

Closed Loop Control of Soft Switched Interleaved Buck Converter

Directory of Open Access Journals (Sweden)

Full Text Available Design, Modeling and Simulation of a closed loop control is presented for Interleaved Buck Converter with Soft Switching. The features of the closed loop system are to reduce the switching losses and load current sharing among the parallel connected converters. The control system of the converter is designed using PWM technique. In order to improve the transient response and dynamic stability of the converters, the controller parameters are designed based on current mode control. Resonant components thus designed enable the application of zero current switching for both the converters connected in parallel thereby maintaining greater efficiency and minimizing voltage and current oscillations. The system analysis, design and performance are verified through simulation using MATLAB/Simulink environment. The simulation approach reveals the high speed dynamic performance of the closed loop system designed using robust PID controller. The laboratory prototype of the Buck converter is developed to verify the controller platform using PIC16F877A microcontroller.

R. Shenbagalakshmi

2012-06-01

335

A 0.35?m 50V CMOS Sliding-Mode Control IC for Buck Converters

DEFF Research Database (Denmark)

This paper presents a hysteretic (sliding mode) control IC for a buck DC/DC converter for use as an envelope tracking power supply to increase the efficiency of an RF power amplifier. The IC integrates a high-bandwidth error amplifier, a comparator with hysteresis, and a high-side driver for an external N-channel power MOSFET. The total control loop delay using the implemented IC is 35ns, this is shown to be a 30% reduction compared to a state-of-the-art discrete IC based solution. The presented results also show that it is viable to integrate a 100MHz operational amplifier on the same die as a high-voltage MOSFET driver operating with slew rates in excess of 5V/ns. The IC is demonstrated in a tracking power supply with 30W output power and 3?s rise/fall time, running from a 40V input. The complete IC, including pads, takes up 4mm2 in a 0.35?m 50V CMOS process.

HØyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

2007-01-01

336

?uk-Buck Converter for Standalone Photovoltaic System

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents MPPT converter for battery charger. The converter combines both ?uk and buck converters to extract the maximum power from the sun while supplying a controlled constant current/voltage to the battery. The topology uses two control signals instead of one control signal; one for tracking the maximum power point, another for charging the battery providing constant current/voltage to the battery. The advantage of this converter is to exploit the maximum power of the PV array avoiding battery damage caused by variable MPPT voltage. The effectiveness of the proposed converter was tested in simulation in various operating conditions.

Ahmad H. El Khateb

2013-01-01

337

A bi-directional DC/DC converter for hybrid wind generator/battery system with state machine control

Energy Technology Data Exchange (ETDEWEB)

A bi-directional DC to DC converter used in a hybrid wind generator/lead-acid battery power system was presented. A state machine control strategy was used to control both the system power flow and load distribution. It was also used to increase the power capacity of the system. The battery was also charged or discharged through the bi-directional DC to DC converter. Multi-stage current charging control of the batteries was accomplished by adjusting the duty cycle of the power converter. This also improved the charging efficiency by the maximum power point tracking algorithm. It was concluded that the proposed control method can be readily extended to other renewable energy conversion systems. 6 refs., 13 figs.

Hua, C.C.; Liao, Y.C. [National Yunlin Univ. of Science and Technology, Yunlin, Taiwan (China). Dept. of Electrical Engineering

2008-07-01

338

Thermal Modeling and Design of On-board DC-DC Power Converter using Finite Element Method

DEFF Research Database (Denmark)

Power electronic converters are widely used and play a pivotal role in electronics area . The temperature causes around 54 % of all power converters failures. Thermal loads are nowadays one of the bottlenecks in the power system design and the cooling efficiency of a system is primarily determined by numerical modeling techniques. Therefore, thermal design through thermal modeling and simulation is becoming an integral part of the design process as less expensive compared to the experimenta l cut - and - try approach. Here the investigation is performed using finite element method - based modeling , and also the potential of such analysis was demonstrated by real - world measurements and comparison of obtained results . Thermal modeling was accomplishe d using finite element anal ysis software COMSOL and thermo - imaging camera was used to measure the thermal field distribution. Also, the improved configuration of power converter was proposed

Staliulionis, Zygimantas; Zhang, Zhe

2014-01-01

339

Soft Computing Module of High Step-Up DC–DC Converter for PV Module using Simulink Environment

Directory of Open Access Journals (Sweden)

Full Text Available Within the photovoltaic (PV power-generation market, the PV module has shown obvious growth. However, a high voltage gain converter is essential for the module’s grid connection through a dc–ac inverter. This paper proposes a converter that employs a floating active switch to isolate energy from the PV panel when the ac module is OFF; this particular design protects installers and users from electrical hazards. Without extreme duty ratios and the numerous turns-ratios of a coupled inductor, this converter achieves a high step-up voltage-conversion ratio; the leakage inductor energy of the coupled inductor is efficiently recycled to the load. These features explain the module’s high-efficiency performance. The detailed operating principles and steady-state analyses of continuous, discontinuous, and boundary conduction modes are described. A 15V input voltage, 200V output voltage, and 100W output power prototype circuit of the proposed converter has been implemented; its maximum efficiency is up to 95.3% and full-load efficiency is 92.3%.

K. Vinoth Kumar

2012-12-01

340

Design of a Fully Integrated Three-Level Buck Converter

Directory of Open Access Journals (Sweden)

Full Text Available Dynamic response of a converter plays an important role in many applications which change load in a rapid manner, especially in POL (Point of load applicant ions. Here a new method for improving the dynamic response of a converter is presented. Here separate control schemes are implemented during steady state as well as transient load conditions. A three level buck converter topology with fast transient response is discussed here. This topology does not require a soft start up circuitry for three level buck converters. Simulation model is done in Matlab/Simulink and the result shows a great improvement in dynamic response of the system. The 3-level converter enables smaller inductors (1 NH than a buck, while generating a wide range of output voltages compared to a 1/2 model capacitor converter. The test-chip prototype delivers up to 0.85 a load current while generating output voltages from 0.4 to 1.4 V from a 2.4 V input supply. It achieves 77% peak efficiency at power density of 0.1 W/mm and 63% efficiency at maximum power density of 0.3 W/mm.

Y. Neelima*,

2014-08-01

341

The objective of this paper is to propose amulti-input power converter for the hybrid system in order tosimplify the power system and reduce the cost. The proposedconverter interfaces two unidirectional input ports and abidirectional port for storage element in a unified structure. Italso utilizes four power switches that are controlled independentlywith four different duty ratios. The renewable power systemhybridizes PV and Wind as main source & Battery Power forbackup energy source. Three d...

Ramya, S.; Manokaran, T.

2012-01-01

342

Simulation of High Step-Up DC–DC Converter for Photovoltaic Module Application using MATLAB/SIMULINK

Directory of Open Access Journals (Sweden)

Full Text Available As per the present scenario lot of power shortages are there in all over the world especially country like India the grid transferring problem is also high. Almost the power from the fossil fuels are becoming so less some of the examples of the fossil fuels are (coal, lignite, oil, and gases.So most of them looking in forward for the power from green or renewable based energies like solar, wind, biomass, tidal etc. Which does not cause any pollution to the environment. In this paper the simulation and analysis of the PV panel and also high efficient boost converter design and simulation is also performed. Even though the solar based systems are renewable based energies when compared to other renewable energies like wind, biomass it does not connect to more number of grid connections. Lot of necessary steps want to be taken one of the main important factor that high efficient boost converter is needed, here in this paper the input voltage to the boost converter is given as 15V and receives the output voltage of 55.64V

S.Daison Stallon

2013-06-01

343

Digital Linear and Nonlinear Controllers for Buck Converter

Directory of Open Access Journals (Sweden)

Full Text Available Both linear PID controllers and fuzzy controllers are designed and implemented for a buck converter. Comparison between the two controllers is made in the aspect of design, implementation and experimental results. Design of fuzzy controllers is based on heuristic knowledge of the converter and tuned using trial and error, while the design of linear PID and PI controllers is based on the frequency response of the buck converter. Implementation of linear controllers is quite straightforward, while implementation of fuzzy controllers has its unique issues. A comparison of experimental results indicates that the performance of the fuzzy controller is superior to that of the linear PID and PI controllers. The fuzzy controller is able to achieve faster transient response, has more stable steady-state response, and is more robust under different operating points.

Shyama M

2012-03-01

344

DEFF Research Database (Denmark)

The Dielectric Electro Active Polymer (DEAP) material is a very thin (~80 ?m) silicone elastomer film with a compliant metallic electrode layer on both sides. The DEAP is fundamentally a capacitor that is capable of very high strain. The property that the polymer changes its shape, as a result of the electrostatic forces generated by an applied voltage, can be used in actuators, for instance to adapt the trailing edges of wind turbine blades, for maximum efficiency and increased energy output. Conventional actuator technologies have not proven feasible solutions for driving the wind turbine flaps. With the DEAP based high power actuator, it is expected to make a reliable and light solution with superior controllability. The current DEAP technology requires high DC voltage in the range of kV to fully utilize the DEAP material as an actuator. In this paper we propose a flyback converter topology to obtain high voltage at low current, for driving the DEAP actuator. Simulation and experimental results for uni-directional flyback converter topology are shown.

Thummala, Prasanth; Zhang, Zhe

2012-01-01

345

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this paper is to propose amulti-input power converter for the hybrid system in order tosimplify the power system and reduce the cost. The proposedconverter interfaces two unidirectional input ports and abidirectional port for storage element in a unified structure. Italso utilizes four power switches that are controlled independentlywith four different duty ratios. The renewable power systemhybridizes PV and Wind as main source & Battery Power forbackup energy source. Three different power operation modes aredefined for the converter based on utilization state of the battery asfollows: 1 An operation type wherein power is delivered to loadfrom hybrid renewable energy sources; 2A single type whereinonly one renewable energy source supplies power to the load withbattery discharging; 3 An operation type wherein power isdelivered to load from renewable sources along with batterycharging. A simple and cost effective control with DC-DCconverter is used for maximum power point tracking (MPPT andhence maximum power is extracted from the source .Theintegration of the hybrid renewable power system is implementedand simulated using MATLAB/SIMULINK.

S. Ramya

2012-11-01

346

DC–DC powering for the CMS pixel upgrade

Energy Technology Data Exchange (ETDEWEB)

The CMS experiment plans to replace its silicon pixel detector with a new one with improved rate capability and an additional detection layer at the end of 2016. In order to cope with the increased number of detector modules the new pixel detector will be powered via DC–DC converters close to the sensitive detector volume. This paper reviews the DC–DC powering scheme and reports on the ongoing R and D program to develop converters for the pixel upgrade. Design choices are discussed and results from the electrical and thermal characterisation of converter prototypes are shown. An emphasis is put on system tests with up to 24 converters. The performance of pixel modules powered by DC–DC converters is compared to conventional powering. The integration of the DC–DC powering scheme into the pixel detector is described and system design issues are reviewed.

Feld, Lutz, E-mail: Lutz.Feld@rwth-aachen.de; Fleck, Martin; Friedrichs, Marcel; Hensch, Richard; Karpinski, Waclaw; Klein, Katja; Rittich, David; Sammet, Jan; Wlochal, Michael

2013-12-21

347

Nonlinear Phenomena in Buck-Boost Power Factor Correction Converter

Directory of Open Access Journals (Sweden)

Full Text Available Buck-Boost Power-Factor-Correction (PFC converter with Average-Current-Model (ACM control is a nonlinear circuit because of the multiplier using and large change in the duty cycle, so its stability analysis must be studied by nonlinear model. In this paper double averaging method is used for describing the model of this converter. By this model we would be able to explain the low frequency dynamics of the system and identify stability boundaries according to circuit parameters and also nonlinear phenomena of this converter are detected.

Mehrnoosh Vatani

2013-01-01

348

Accurate Sliding-Mode Control System Modeling for Buck Converters

DEFF Research Database (Denmark)

This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively modeling the hysteretic comparator as an infinite gain. Correct prediction of output impedance is shown to be enabled by the use of a more elaborate, finite-gain model of the hysteretic comparator, which takes the effects of time delay and finite switching frequency into account. The demonstrated modeling approach also predicts the self-oscillating switching action of the sliding-mode control system correctly. Analytical findings are verified by simulation as well as experimentally in a 10-30V/3A buck converter.

HØyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

2007-01-01

349

On-chip SIDO buck converter with independent outputs

The portable electronics market is rapidly migrating towards more compact devices requiring multiple high-integrity high-efficiency voltage supplies for empowering the systems. This paper demonstrates a single inductor used in a buck converter with two output voltages from an input battery with voltage of value 3 V. The main targets are low cross regulation between the two outputs to supply independent load current levels while maintaining desired output voltage values well within the accepta...

Marti?nez Garci?a, Herminio; Silva-marti?nez, Jose?

2013-01-01

350

Directory of Open Access Journals (Sweden)

Full Text Available An intelligent fuzzy logic inference pipeline for the control of a dc-dc buck-boost converter was designed and built using a semi-custom VLSI chip. The fuzzy linguistics describing the switching topologies of the converter was mapped into a look-up table that was synthesized into a set of Boolean equations. A VLSI chip–a field programmable gate array (FPGA was used to implement the Boolean equations. Features include the size of RAM chip independent of number of rules in the knowledge base, on-chip fuzzification and defuzzification, faster response with speeds over giga fuzzy logic inferences per sec (FLIPS, and an inexpensive VLSI chip. The key application areas are: 1 on-chip integrated controllers; and 2 on-chip co-integration for entire system of sensors, circuits, controllers, and detectors for building complete instrument systems.

Vaidhyanathan Jagannathan

2010-03-01

351

Nonlinear Phenomena in Buck-Boost Power Factor Correction Converter

Buck-Boost Power-Factor-Correction (PFC) converter with Average-Current-Model (ACM) control is a nonlinear circuit because of the multiplier using and large change in the duty cycle, so its stability analysis must be studied by nonlinear model. In this paper double averaging method is used for describing the model of this converter. By this model we would be able to explain the low frequency dynamics of the system and identify stability boundaries according to circuit parameters and also nonl...

Mehrnoosh Vatani; Soodabeh Soleymani; Mehrdad Ahmadi Kamarposhti

2013-01-01

352

Directory of Open Access Journals (Sweden)

Full Text Available This document proposes analysing and designing two control strategies for permanent current DC-DC buck converter. These kinds of electronic devices convert a constant-voltage to a lower constant-voltage (nonlinearity characteristics being demonstra- ted. Two nonlinear control techniques are shown. The first is a conventional optimal proportional error and integral error (PI controller based on minimising integral of time per squared errors (ITSE criteria. A model of the plant at an operation point was thus obtained. The second one was fuzzy control where input and output sets were also defined by minimising ITSE criteria in the overall system and establishing inputs such as proportional error and integral error. Load was then varied to establish the system’s efficiency with both the aforementioned controllers. It must be borne in mind that such systems should not present super-voltage since this can cause damage. The parameters found in designing both controllers thus corresponded to analytical and descriptive methodology. Simulation results, the performance index mentioned above (ITSE and power consumption showed that the sys- tem’s response for the fuzzy control drew more power consumption than the optimal controller; otherwise, obtained ITSE was lar- ger for the optimal control than the fuzzy control. It is concluded that exploring these types of converter is applicable when using nonlinear control techniques and minimising the different performance indices.

Lina Morales Laguado

2010-05-01

353

Design Of Converter For Low Power Photovoltaic Conversion System

The solar energy conversion system is an alternative for conventional power generating system. It has no running cost due to freely available and non polluting solar radiations. The voltage which is available from solar array is variable and to obtain a stable voltage from solar panels, DC-DC converters are required for constant power production. There are mainly three converters namely Buck, Boost and Buck-Boost converters which can be used for either increasing or decreasing the voltage. Th...

Swapnil Zadey, Subroto Dutt

2013-01-01

354

Scientific Electronic Library Online (English)

Full Text Available Este artículo propone un pre-amplificador basado en convertidores DC-DC conectados en paralelo para la reducción de armónicos inyectados a fuentes de potencia. Las principales características del pre-amplificador son la reducción del rizado de corriente de entrada en convertidores de potencia, incre [...] mentado además la eficiencia del sistema de conversión. Se describe el cálculo de las condiciones óptimas de operación del pre-amplificador, así como su modelado matemático y control para operar en las condiciones seleccionadas. Así mismo, se analiza el pre-amplificador con un convertidor elevador clásico, obteniendo una reducción significativa en el rizado de corriente inyectado a la fuente, así como un incremento en la eficiencia del sistema. Finalmente, los análisis teóricos se confirman a través de simulaciones circuitales y resultados experimentales. Abstract in english An efficient pre-amplifier based on interleaved DC-DC boost switching converters to mitigate high-frequency harmonics injection to power sources is proposed. The main features of the pre-amplifier are mitigate the ripple of power converters input-current and improving the efficiency of the whole pow [...] er conversion chain. The pre-amplifier optimal operating conditions are calculated, and the circuit is modeled and controlled to operate in such conditions. The pre-amplifier interacting with a classical single boost is analyzed, obtaining a strong reduction in the current ripple injected to the source, and also improving the efficiency of the initial conversion system. Finally, the theoretical analyses are confirmed by means of circuital PSIM simulations and experimental results.

Eliana, Arango; Carlos, Ramos-Paja; Carlos, Carrejo; Roberto, Giral; Andres, Saavedra-Montes.

2011-09-01

355

Series connections of energy-storage modules such as electric double-layer capacitors (EDLCs) and lithium-ion batteries result in voltage imbalance because of the nonuniform properties of individual modules. Conventional voltage equalizers based on traditional dc-dc converters require numerous switches and/or transformers, and therefore, their costs and complexity tend to increase. This paper proposes a novel single-switch equalization charger using multiple stacked buck-boost converters. The single-switch operation not only reduces the circuit complexity but also contributes to increasing the reliability. The fundamental operating principles and design procedures of key components are presented in detail. An experimental charge test using a 25W prototype of the proposed equalization charger was performed for four series-connected EDLC modules whose initial voltages were intentionally imbalanced. Experimental results demonstrated that the proposed equalization charger could charge the series-connected modules preferentially in the order of increasing module voltage and that all the modules could be charged up to a uniform voltage level.

Uno, Masatoshi; Tanaka, Koji

356

DEFF Research Database (Denmark)

This paper presents a digital control technique to achieve valley switching in a bidirectional flyback converter used to drive a dielectric electro active polymer based incremental actuator. The incremental actuator consists of three electrically isolated, mechanically connected capacitive actuators. The incremental actuator requires three high voltage (~2.5 kV) bidirectional DC-DC converters, to accomplish the incremental motion by charging and discharging the capacitive actuators. The bidirectional flyback converter employs a digital controller to improve efficiency and charge/discharge speed using the valley switching technique during both charge and discharge processes, without the need to sense signals on the output high-voltage side. Experimental results verifying the bidirectional operation of a single high voltage flyback converter are presented, using a film capacitor as the load. Energy efficiency measurements are provided.

Thummala, Prasanth; Zhang, Zhe

2014-01-01

357

Implementation of PV System with Two Inductor Buck Boost Converter

Directory of Open Access Journals (Sweden)

Full Text Available The project proposes a new converter for photovoltaic system which is substantially high performance oriented. Furthermore, the lack of batteries replacement water pumping systems without the use of chemicals are responsible for the failure of such systems in isolated areas. The converter is designed to drive a three-phase induction motor directly from photovoltaic system. The majority of commercial systems use low-voltage (PV energy. The use of three-phase induction motor presents a suitable replacement of dc motor though by the use of dc motor we can directly drive by means of converter dc supply, but due to its lack of performance and reliability, we have opted for three phase induction motor. In the developed technique, there is no specialized personnel for operating and the system is based on a current-fed multi-resonant converter also maintaining these motors. Here, we make use of the TIBC topology such that they are found to be made of Buck Boost converter which will both stabilize and boost the output supply. Thus, the project will be a low cost high efficiency water supply duo for agricultural industry. Though solar energy based water supply system is being developed for the past 20 years, this project will be a phenomenal change and development of renewable energy that could be used in agricultural industry projects.

T.Jeevanandham, M.Raja

2015-03-01

358

The DC-DC Conversion Power System of the CMS Phase-1 Pixel Upgrade

The power system of the Phase-1 pixel detector will be described and the performance of the new components, including DC-DC converters, DC-DC converter motherboards and various power distribution boards, will be detailed. The outcome of system tests in terms of electrical behaviour, thermal management and pixel module performance will be discussed.

Klein, Katja

2014-01-01

359

Extended time-delay autosynchronization for the buck converter

Time-delay autosynchronization (TDAS) can be used to stabilize unstable periodic orbits in dynamical systems. The technique involves continuous feedback of signals delayed by the orbit's period. One variant, ETDAS, uses information further in the past. In both cases, the feedback signal vanishes on the target periodic orbit and hence the stabilized periodic orbit is one of the original dynamical system. Furthermore, this control method only requires the knowledge of the period of the unstable orbit. The amount of feedback gain needed to achieve stabilization varies with the bifurcation parameter(s) of the system, resulting in a domain of control. In this paper we compute the domain of control of the unstable periodic orbits of the \\textit{buck} converter. We obtain a closed analytical expression for the curve $g:S^1 \\rightarrow\\C$ whose index determines the stability, and this index is then numerically computed. We run several simulations of the controlled system and discuss the results.

Batlle, C; Olivar, G

1996-01-01

360

Application of a buck-type MC2 regulated converter for a stepper motor control

Stepper Motor Control (MC) using twin bidirectional buck converters is presented. The system can be split in two by providing digital electronics for the generation of sine reference voltages with variable frequency, or by means of analog electronics using two buck regulators, each followed by an inverter bridge that drives the stepper motor. The sine reference with variable frequency is used to avoid vibrations on the motor axis. The digital circuit outputs its data via a digital to analog converter that gives the rectified value and sign of the sinusoidal signals to the buck converters of the analog part and bridge-inverter which allows for a bipolar motor current.

Decoligny, M.; Dullaart, L. J.; Rodriguez, R.; Capdepuy, M.; Capel, A.; Battle, A.

1989-08-01

361

DEFF Research Database (Denmark)

This paper introduces a new zero-voltage-switching (ZVS) isolated DC-DC converter with two input ports which can be utilized in hybrid energy systems, for instance, in a fuel cell and super-capacitor system. By fully using two high frequency transformers, the proposed converter can effectively integrate a current-fed boost half-bridge (BHB) and a full-bridge (FB) into one equivalent circuit configuration which has dual-input ability and additionally it can reduce the number of the power devices. With the phase-shift control, it can achieve zero-voltage switching turn-on of active switches and zero-current switching (ZCS) turn-off of diodes leading to negligible reverse recovery loss. Voltage conversion ratio is higher compared to the conventional boost converter owing to the BHB circuit and the corresponding control. Finally, a 25~50 V input, 300~400 V output prototype with a 600 W nominal power rating are built up and tested to demonstrate the effectiveness of the proposed converter topology.

Zhang, Zhe; Thomsen, Ole Cornelius

2013-01-01

362

Energy Technology Data Exchange (ETDEWEB)

This paper presents the analysis and novel hybrid controller design for an interleaved 2-quadrant switched capacitor (SC) bidirectional DC/DC converter for a hybrid electric vehicle (HEV) dual energy storage system. The designed novel control strategy enables simpler dynamics compared to a standard buck converter with input filter, good regulation capability, low EMI, lower source current ripple, ease of control, and continuous input current waveform in both buck as well as boost modes of operation.

Amjadi, Zahra; Williamson, Sheldon

2010-09-15

363

In recent years, power demand of industrial applications has increased significantly reaching some megawatts. The use of multilevel converters for applications of medium and high powers is proposed as a solution to drawback semiconductor technology. A multilevel converter not only achieves high power ratings, but also enables the use of renewable energy sources. Renewable energy sources such as photovoltaic can be easily interfaced to a multilevel converter...

Mechouma Rabiaa; Azoui Boubekeur

2014-01-01

364

DESIGN AND IMPLEMENTATION OF BRIDGELESS BUCK CONVERTER WITH FUZZY CONTROLLER FED PMDC DRIVE

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the Fuzzy controller based bridgeless buck converter has been estimated and the performance of the converter is analyzed. This converter has advantages like reduced switching losses, stresses and EMI. The method to predict the steady state and dynamic performance of the converter fed with PMDC motor operation has been presented. The proposed converter has been analyses with the closed loop and open loop condition. The simulation study indicates the superiority of fuzzy control over the conventional control methods. A prototype Buck converter is designed and experimentally demonstrated. The prototype is tested for the steady state and transient conditions. Comparison between experimental and simulations show a very good agreement and the reliability of fuzzy controller.

C. Nagarajan

2012-04-01

365

Reduce Energy Losses and THD in Buck Converter Using Control Algorithm

The paper will focus on modeling, analysis, and design and simulation buck converter architecture. This architecture is used for automotive dual power system to reduce filters, dynamic response and power. The converter is designed in CCM (continuous conduction mode). The voltage mode control strategy is proposed by using pulse width modulation (PWM) with a proportional-integralderivative (PID). The effectiveness of the step down converter is verified through simulation results using control o...

Vipul C Rajyaguru, Keerti S. Vashishtha

2012-01-01

366

This paper proposes an interleaved multiphase buck converter with minimum time control strategy for envelope amplifiers in high efficiency RF power amplifiers. The solution of the envelope amplifier is to combine the proposed converter with a linear regulator in series. High system efficiency can be obtained through modulating the supply voltage of the envelope amplifier with the fast output voltage variation of the converter working with several particular duty cycles that achieve tot...

Cheng, Pengming; Vasic, Miroslav; Garci?a Sua?rez, Oscar; Oliver Rami?rez, Jesu?s Angel; Alou Cervera, Pedro; Cobos Ma?rquez, Jose? Antonio

2011-01-01

367

Simulation and Implementation a Non-Isolated Buck Converter at ZCS Condition

Directory of Open Access Journals (Sweden)

Full Text Available A new soft-switching resonant inverting-buck converter with high efficiency is presented. The proposed converter steps down and inverts the input voltage. The zero-current-switching (ZCS technique is employed to reduce switching losses and Electromagnetic Interferences (EMI. An LLC resonant network is utilized to provide soft-switching conditions for all semiconductor devices. Experimental results verify the integrity of the proposed converter operation and the presented theoretical analysis.

Nahid Hematian

2013-10-01

368

Energy Technology Data Exchange (ETDEWEB)

A soft switching method with small switching loss was proposed for the purpose of increasing the efficiency of a DC-DC boost converter which converted a DC current generated by solar cells to a variable DC current. Existing current converters are supplemented by using a snubber circuit around the switch so as to protect the switch by a hard switching action. However, with an increase of the output current, snubber loss is increased, reducing the efficiency. In order to solve this problem, the partial resonant switch method was applied to the converter; with this method of partially forming a resonant circuit only at the time of turning on/off of the switch, the switching loss was reduced through the soft switching, thereby making the proposed converter operate with high efficiency. Moreover, the resonant element of the partial resonant circuit using a snubber condenser, the energy accumulated in the condenser was regenerated on the power supply side without loss of snubber. With the regenerated energy, the proposed converter was provided with a smaller ratio of switching to use than the conventional converter. 4 refs., 7 figs., 1 tab.

Lee, H. [Kyungnam University (Korea, Republic of)

1996-10-27

369

Energy Technology Data Exchange (ETDEWEB)

The square wave series voltage compensator is an equipment used to mitigate voltage sags. In the case of occurrence of a voltage disturbance, the compensator acts generating a square wave voltage to supply the missing voltage. The energy inserted for the compensation is taken from the electrical grid, by a linear source. The purpose of this paper is to present a switching shunt converter instead of a linear one, with the same output parameters in order to increase the power density. This efficiency is demonstrated by simulations. (author)

Moreira, Angelo Roberto Rodrigues Resende; Caetano, William Douglas; Pires, Igor Amariz; Silva, Arlete Vieira da [Centro Universitario de Belo Horizonte (UnBH), MG (Brazil)], e-mails: angelogalo2005@hotmail.com, wdouglasbh@gmail.com, igor_amariz@yahoo.com.br, arlete.silva@prof.unibh.br

2011-07-01

370

This paper presents a new PWM Multi phase DC-DC converter under current mode control with an auxiliary circuit which provides zero voltage switching in order to meet the power supply requirements of the processors of modern electronic equipments like laptops, mobiles, and PDAs etc which require more than 70 A current, lower voltage and better transient response.The multi phase topology benefits in high current, good efficiency and better current transient response. High current multi phase b...

Sastry, Nittala S. K.; Dr. Swapnajit Pattnaik

2012-01-01

371

Based on the fact that the real inductor and the real capacitor are fractional order in nature and the fractional calculus, the transfer function modeling and analysis of the open-loop Buck converter in a continuous conduction mode (CCM) operation are carried out in this paper. The fractional order small signal model and the corresponding equivalent circuit of the open-loop Buck converter in a CCM operation are presented. The transfer functions from the input voltage to the output voltage, from the input voltage to the inductor current, from the duty cycle to the output voltage, from the duty cycle to the inductor current, and the output impedance of the open-loop Buck converter in CCM operation are derived, and their bode diagrams and step responses are calculated, respectively. It is found that all the derived fractional order transfer functions of the system are influenced by the fractional orders of the inductor and the capacitor. Finally, the realization of the fractional order inductor and the fractional order capacitor is designed, and the corresponding PSIM circuit simulation results of the open-loop Buck converter in CCM operation are given to confirm the correctness of the derivations and the theoretical analysis.

Wang, Fa-Qiang; Ma, Xi-Kui

2013-03-01

372

International Nuclear Information System (INIS)

Based on the fact that the real inductor and the real capacitor are fractional order in nature and the fractional calculus, the transfer function modeling and analysis of the open-loop Buck converter in a continuous conduction mode (CCM) operation are carried out in this paper. The fractional order small signal model and the corresponding equivalent circuit of the open-loop Buck converter in a CCM operation are presented. The transfer functions from the input voltage to the output voltage, from the input voltage to the inductor current, from the duty cycle to the output voltage, from the duty cycle to the inductor current, and the output impedance of the open-loop Buck converter in CCM operation are derived, and their bode diagrams and step responses are calculated, respectively. It is found that all the derived fractional order transfer functions of the system are influenced by the fractional orders of the inductor and the capacitor. Finally, the realization of the fractional order inductor and the fractional order capacitor is designed, and the corresponding PSIM circuit simulation results of the open-loop Buck converter in CCM operation are given to confirm the correctness of the derivations and the theoretical analysis

373

In this paper, an interleaved multiphase buck converter with minimum time control strategy for envelope amplifiers in high efficiency RF power amplifiers is proposed. The solution for the envelope amplifier is to combine the proposed converter with a linear regulator in series. High efficiency of envelope amplifier can be obtained through modulating the supply voltage of the linear regulator. Instead of tracking the envelope, the buck converter has discrete output voltage that corresponding t...

Cheng, Pengming; Vasic, Miroslav; Garci?a Sua?rez, Oscar; Oliver Rami?rez, Jesu?s Angel; Alou Cervera, Pedro; Cobos Ma?rquez, Jose? Antonio

2011-01-01

374

Energy Technology Data Exchange (ETDEWEB)

The present contribution describes the CuK-converter. It is a bi-directional, high and low-changing DC-to-DC converter. It distinguishes itself by its design but it is not easy to control. A condition control system has been developed with various tools and a mathematical description of the converter (State-space averaging). It was proved that different tools (SIMPLORER, PSPICE, Matlab, C) and methods (discrete simulation, State-space averaging) support the design of the control system. The results were verified by comparative calculations (simulations). This is important, because the results of a simulation should always be tested for being plausible in order to avoid adjustment mistakes of the program or false modelling. Even though individual simulation tools have specific advantage, their functions resemble each other more and more due to very fast engineering. Hence it depends on the subjective criteria of the user, which simulation tool is used for a certain problem, e.g. if he knows the program or if a simple, almost intuitive handling is possible. (orig.) [German] Im vorliegenden Beitrag wurde der Cuk-Wandler vorgestellt. Es ist ein bidirektionaler, hoch- u. tiefsetzender DC/DC-Wandler. Er besticht durch seinen einfachen Aufbau, ist aber dennoch nicht einfach zu regeln. Mit verschiedenen Werkzeugen und einer mathematischen Beschreibung des Wandlers (State-space averaging) wurde eine Zustandsregelung entwickelt. Gezeigt wurde, dass verschiedene Werkzeuge (SIMPLORER, PSPICE, Matlab, C) und Methoden (diskrete Simulation, State-space averaging) den Reglerentwurf unterstuetzen. Dabei wurden die Ergebnisse mit Vergleichsrechnungen (Simulationen) verifiziert. Dieses ist wichtig, da die Ergebnisse einer Simulation immer auf Plausibilitaet geprueft werden sollten, um Einstellungsfehler des Programms oder eine fehlerhafte Modellierung zu vermeiden. Obwohl die einzelnen Simulationstools ueber spezifische Vorteile verfuegen, ueberdecken sie sich aufgrund ihrer rasanten Entwicklung in der Funktionalitaet immer staerker. Welches Simulationstool daher fuer ein bestimmtes Problem eingesetzt wird, haengt stark von subjektiven Kriterien des Benutzers ab, z.B. ob er das Programm kennt oder eine einfache, moeglichst intuitive Bedienung moeglich ist. (orig.)

Engler, A. [Institut fuer Solare Energieversorgungstechnik (ISET), Kassel (Germany)

1999-07-01

375

Space-state robust control of a Buck converter with amorphous core coil and variable load

Pulse-width modulation is widely used to control electronic converters. One of the most frequently used topologies for high DC voltage/low DC voltage conversion is the Buck converter. These converters are described by a second order system with an LC filter between the switching subsystem and the load. The use of a coil with an amorphous magnetic material core rather than an air core permits the design of smaller converters. If high switching frequencies are used to obtain high quality voltag...

Morales Cabrera, Rafael; Somolinos Sanchez, Jose Andres; Moron Fernandez, Carlos; Garcia Garcia, Alfonso

2013-01-01

376

Zero-Voltage and Zero-Current Switching Buck-Boost Converter for PV Applications

A ZVS and ZCS buck boost converter is presented for PV panel applications. The salient points are that all the switching devices are under zero-current switching during turn-on and zero-voltage switching during turn-off. The active switches in the converter undergo zero-capacitive turn-on losses unlike switches in other soft-switched topologies. The switches do not experience any over voltage/over current stress proportional to load as in resonant converters. This soft-switching technique can...

Prem, Athulya P.; Sudhin Govind; Ravi, Chinnu P.

2014-01-01

377

Advanced buck converter power supply ABCPS for APT

International Nuclear Information System (INIS)

The United States Department of Energy (DOE) is planning to fabricate an Accelerator for the Production of Tritium (APT) at their Savannah River Site, to provide Tritium for national defense. The 1700 million electron volt (MeV) proton beam accelerator will be powered by radio frequency (RF) klystrons. A direct current (DC) power supply is required for each of the approximately two hundred and fifty 1-megawatt (MW) continuous wave klystrons in the RF power system. The requirements are that the power supply meet output performance specifications, provide fault protection for the klystron, have high efficiency, high reliability, good maintainability, and be readily manufacturable. As the power supplies are one of the largest cost elements in the accelerator, a technology review was made to determine the most economical approach to satisfy the requirements. A switch-mode power supply employing a buck-regulator was identified as being potentially the lowest cost approach. As the switch represents a certain development risk, a small-scale prototype has been constructed for evaluation, and has resulted in the decision to fabricate a full-scale prototype power supply. A description of the hardware will be presented

378

Sliding mode control of boost and buck-boost power converters using the dynamic sliding manifold

Energy Technology Data Exchange (ETDEWEB)

Non-minimum phase tracking control is studied for boost and buck-boost power converters. A sliding mode control algorithm is developed to track directly a causal voltage tracking profile given by an exogenous system. The approximate causal output non-minimum phase asymptotic tracking in non-linear boost and buck-boost power converters is addressed via sliding mode control using a dynamic sliding manifold (DSM). Use of DSM allows the stabilization of the internal dynamics when the output tracking error tends asymptotically to zero in the sliding mode. The sliding mode controller with DSM links features of conventional sliding mode control (insensitivity to matched non-linearities and disturbances) and a conventional dynamic compensator (accommodation to unmatched disturbances). Numerical examples demonstrate the effectiveness of the sliding mode controller even for a known time-varying load. (Author)

Shtessel, Yuri B. [Alabama Univ., Dept. of Electrical and Computer Engineering, Huntsville, AL (United States); Zinober, Alan S.I. [Sheffield Univ., Dept. of Applied Mathematics, Sheffield (United Kingdom); Shkolnikov, Ilia A. [Z/I Imaging Corp., Huntsville, AL (United States)

2003-07-01

379

Modelling and Simulation of Closed Loop Controlled Buck Converter Fed Pmbldc Drive System

Permanent Magnet Brushless DC Motor (PMBLDC) is one of the best electrical drives that has increasing popularity, due to their high efficiency, reliability, good dynamic response and very low maintenance. This makes the interest of modeling an ideal PMBLDC motor and it’s associated Drive System in simple and lucid manner. In this paper the drive system is proposed with a buck converter topology. It has the advantages of reduced switching losses, low inductor power loss, reduced ripple by us...

Dhanasekaran, R.; Prakash, S.

2011-01-01

380

Modeling and Simulation of Non-ideal Buck Converter in DCM

The modeling method is exemplified by Buckconverter operating in the discontinuous conduction mode(DCM), taking into account all parasitic resistances, thresholdvoltage of diode and inductor current ripples existing in actualconverters. Based on the theory of switch average model, timeaverage method of equivalent circuit, the theory of energyconservation, a circuit averaging method is studied to modelnon-ideal Buck converters operating in DCM, and a duty ratioconstraint which leads to a full ...

Sheng-yu Gong,; Lin Chen, Chang-hu Yu

2012-01-01

381

Design And Implementation Of Luo Converter For Electric Vehicle Applications

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes the stable and ripple free output voltage from the design of developed Dc-Dc converter topology. Dc voltage provided by battery contains high voltage ripples and it is not constant enough voltage, thus it is not applicable for most devices like electric-vehicle controller, dc-chargers, etc. Dc-Dc converters are employed to attenuate the ripples regardless of change in the load voltage. In the existing method, the classical buck converter for electric vehicle applications does not meet the load requirement containing more ripples on the output voltage and parasitic effects. To overcome this problem the advanced developed Dc-Dc luo-converter technology was introduced. luo converter is the developed converter derived from the buck-boost converter. In this proposed model the additional filter elements in the luo-converter eliminate the output ripples and effectively enhance the output voltage level. A computer simulation using MATLAB/SIMULINK confirms the predicted results.

A.Manikandan

2013-10-01

382

Zero-Voltage and Zero-Current Switching Buck-Boost Converter for PV Applications

Directory of Open Access Journals (Sweden)

Full Text Available A ZVS and ZCS buck boost converter is presented for PV panel applications. The salient points are that all the switching devices are under zero-current switching during turn-on and zero-voltage switching during turn-off. The active switches in the converter undergo zero-capacitive turn-on losses unlike switches in other soft-switched topologies. The switches do not experience any over voltage/over current stress proportional to load as in resonant converters. This soft-switching technique can also be applied to other classical switched mode power converters. A detailed analysis of the converter under steady state is discussed and simulation results obtained are presented.

Athulya P Prem

2014-12-01

383

A New Buck-Boost Converter for a Hybrid-Electric Drive Stand

This paper describes work on the laboratory working stand for a hybrid-electric drive located in laboratory T2:H1-26.The basic idea is to operate the combustion engine in its optimal regime. In this regime the engine has the highest efficiency and minimal smoke exhaust. This optimal regime is only a small portion of its operation area. Because the engine has to operate in this area, it is necessary to add a new converter to the hybrid-electric stand. The new converter must be allowed to buck ...

Mas?ek, P.

2009-01-01

384

Design and simulation of fuzzy controlled quasi resonant buck converter

A controller based on Fuzzy logic is implemented and its application to the regulation of power converter is investigated. Being free of complex equations and heavy computation, it achieves fast dynamic response and adapts to varying conditions of operation. The topology is modeled using MATLAB software and operated at finite higher switching frequency to evaluate its closed-loop performance in respect of line and load regulation. It is verified by transient characteristics that due to quasi-...

Rameshkumar, A.; Arumugam, S.

2009-01-01

385

Krav på ingångsgränssnittet till kortmonterade DC/DC-omvandlare

This thesis has been carried out on behalf of the department of Power Modules at Ericsson. In a telecom system interface A is a physical point between the power supply system and the telecommunication equipment described in a European standard called ETSI EN 300 132-2. This interface is also described in the American standard ATIS-0600315.2007. For board-mounted products, such as DC/DC converters, a well-defined input interface description is lacking. The goal of this thesis was to evaluate ...

Croneba?ck, Alexandra

2013-01-01

386

Design and simulation of fuzzy controlled quasi resonant buck converter

Directory of Open Access Journals (Sweden)

Full Text Available A controller based on Fuzzy logic is implemented and its application to the regulation of power converter is investigated. Being free of complex equations and heavy computation, it achieves fast dynamic response and adapts to varying conditions of operation. The topology is modeled using MATLAB software and operated at finite higher switching frequency to evaluate its closed-loop performance in respect of line and load regulation. It is verified by transient characteristics that due to quasi-resonance there is a drastic change in peak overshoot and settling time and the proposed strategy has good rejection ability for supply and load disturbances.

A. Rameshkumar

2009-07-01

387

The DC-DC conversion power system of the CMS Phase-1 pixel upgrade

The pixel detector of the CMS experiment will be exchanged during the year-end technical stop in 2016/2017, as part of the experiment's Phase-1 upgrade. The new device will feature approximately twice the number of readout channels, and consequently the power consumption will be doubled. By moving to a DC-DC conversion powering scheme, it is possible to power the new pixel detector with the existing power supplies and cable plant. The power system of the Phase-1 pixel detector is described and the performance of the new components, including DC-DC converters, DC-DC converter motherboards and various power distribution boards, is detailed. The outcome of system tests in terms of electrical behaviour, thermal management and pixel module performance is discussed.

Feld, L.; Karpinski, W.; Klein, K.; Lipinski, M.; Preuten, M.; Rauch, M.; Schmitz, St.; Wlochal, M.

2015-01-01

388

Sliding mode control for half-wave zero current switching quasi-resonant buck converter

Energy Technology Data Exchange (ETDEWEB)

This paper focuses on the practical implementation of sliding mode control (SMC) in a half-wave zero current switching quasi-resonant Buck converter. SMC can manipulate efficiently the nonlinear phenomena that appear in switch mode power supplies, furthermore SMC is less affected by disturbances compared to other control techniques, and it is not operating at a constant switching frequency. Since half wave zero current switching quasi-resonant buck converter is not operating at a constant switching frequency and it is sensitive to dynamic variation, SMC is selected in this paper as a control technique. An explanation of the implementation of SMC, and selecting its parameters is given. A detailed mathematical analysis is performed in order to select the appropriate values of the tank components elements. The tank inductor value is assumed to be small and constant, and a range of tank capacitor values is obtained. The prototype of an analog sliding mode control for the converter is constructed. In order to study the effect of SMC on the converter behavior, the system is tested in the steady state and under different load value conditions. The obtained graphs show that the performance of SMC is good, even under the worst load conditions, i.e. no load and full load. (author)

Ahmed, M.; Kuisma, M.; Silventoinen, P.

2004-07-01

389

Sensorless Load Torque Estimation and Passivity Based Control of Buck Converter Fed DC Motor

Passivity based control of DC motor in sensorless configuration is proposed in this paper. Exact tracking error dynamics passive output feedback control is used for stabilizing the speed of Buck converter fed DC motor under various load torques such as constant type, fan type, propeller type, and unknown load torques. Under load conditions, sensorless online algebraic approach is proposed, and it is compared with sensorless reduced order observer approach. The former produces better response in estimating the load torque. Sensitivity analysis is also performed to select the appropriate control variables. Simulation and experimental results fully confirm the superiority of the proposed approach suggested in this paper.

Kumar, S. Ganesh; Thilagar, S. Hosimin

2015-01-01

390

Reduce Energy Losses and THD in Buck Converter Using Control Algorithm

Directory of Open Access Journals (Sweden)

Full Text Available The paper will focus on modeling, analysis, and design and simulation buck converter architecture. This architecture is used for automotive dual power system to reduce filters, dynamic response and power. The converter is designed in CCM (continuous conduction mode. The voltage mode control strategy is proposed by using pulse width modulation (PWM with a proportional-integralderivative (PID. The effectiveness of the step down converter is verified through simulation results using control oriented simulator like MATLAB/Simulink tools.The proposed circuits operate at constant frequency and are regulated by conventional pulse width modulation (PWM using dedicated PWM and PID control techniques. The circuit operation, mathematical analysis, designs and simulation results for continuous current mode (CCM operation are mentioned in this paper.

Vipul C. Rajyaguru, Keerti S.Vashishtha, K. C. Dave

2012-04-01

391

Steady-state analysis of dead-time effect on bidirectional buck converters

DEFF Research Database (Denmark)

Half-bridge inverters, full-bridge inverters and bidirectional buck converters share a common topological structure, in which two switches and two diodes are present. In such a topology, a dead time between the two signals controlling the switches is inserted. This influences the relationship between output voltage, input voltage and duty cycle as a function of the output current. In the literature, the dead-time effect has been studied in relation with inverters, active filters, voltage regulated modules and high-precision power amplifiers, and dead-time compensation techniques have been proposed. However, the measurement of the current is normally required for all dead-time compensation strategies, which can be a problem when the current approaches or crosses zero. In this paper, the operation of a bidirectional buck converter in the region around zero current has been analytically analyzed. It has been shown that in a region around zero there is no dead-time effect. The analytical expression of the bordersbetween the areas where the dead-time effect is positive, zero or negative has been given. Moreover it has been shown that between these three areas, there are four other transitional areas. The analytical analysis has been confirmed by simulation and experimental results.

Bidoggia, Benoit; Maheshwari, Ram Krishan

2012-01-01

392

Directory of Open Access Journals (Sweden)

Full Text Available This paper investigates the performance perspectives and theoretical limitations of trench power MOSFETs in synchronous rectifier buck converters operating in the MHz frequency range. Several trench MOSFET technologies are studied using a mixed-mode device/circuit modeling approach. Individual power loss contributions from the control and synchronous MOSFETs, and their dependence on switching frequency between 500Ã¢Â€Â‰kHz and 5Ã¢Â€Â‰MHz are discussed in detail. It is observed that the conduction loss contribution decreases from 40% to 4% while the switching loss contribution increases from 60% to 96% as the switching frequency increases from 500Ã¢Â€Â‰KHz to 5Ã¢Â€Â‰MHz. Beyond 1Ã¢Â€Â‰MHz frequency there is no obvious benefit to increase the die size of either SyncFET or CtrlFET. The RDS(ONÃƒÂ—QG figure of merit (FOM still correlates well to the overall converter efficiency in the MHz frequency range. The efficiency of the hard switching buck topology is limited to 80% at 2Ã¢Â€Â‰MHz and 65% at 5Ã¢Â€Â‰MHz even with the most advanced trench MOSFET technologies.

Xu Cheng

2008-06-01

393

A 10 MHz ripple-based on-time controlled buck converter with dual ripple compensation

A 10 MHz ripple-based on-time controlled buck converter is presented. A novel low-cost dual ripple compensation, which consists of coupling capacitor compensation and passive equivalent series resistance compensation, is proposed to achieve a fast load transient response and robust stability simultaneously. Implemented in a 2P4M 0.35 ?m CMOS process, the converter achieves fix-frequency output with a ripple of below 10 mV and an overshoot of 10 mV at 400 mA step load transient response. With width optimization of the power transistors in an ultra-heavy load and PFM control in a light load, the efficiency stays at over 83% for a load range from 20 mA to 1.5 A and the peak efficiency reaches 90.16%.

Danzhu, Lü; Jiale, Yu; Zhiliang, Hong

2013-02-01

394

A 10 MHz ripple-based on-time controlled buck converter with dual ripple compensation

International Nuclear Information System (INIS)

A 10 MHz ripple-based on-time controlled buck converter is presented. A novel low-cost dual ripple compensation, which consists of coupling capacitor compensation and passive equivalent series resistance compensation, is proposed to achieve a fast load transient response and robust stability simultaneously. Implemented in a 2P4M 0.35 ?m CMOS process, the converter achieves fix-frequency output with a ripple of below 10 mV and an overshoot of 10 mV at 400 mA step load transient response. With width optimization of the power transistors in an ultra-heavy load and PFM control in a light load, the efficiency stays at over 83% for a load range from 20 mA to 1.5 A and the peak efficiency reaches 90.16%. (semiconductor integrated circuits)

395

A Tapped-Inductor Buck-Boost Converter for a Dielectric ElectroActive Polymer Generator

DEFF Research Database (Denmark)

Energy harvesting applications based on Dielectric ElectroActive Polymer (DEAP) generators have been in the spotlight in recent years after the latter ones’ documented advantages against competing electromagnetic and field-activated technologies. Yet, the need for bidirectional energy flow under high step-up and high step-down voltage conversion ratios, accompanied by low-average but relatively high-peak currents, imposes great challenges on the design of the employed power electronic converter. In addition, the effective operational range of the converter is usually limited by the lack of commercially-available, high-efficient, high-voltage, low-power semiconductor devices. In this paper, a high-efficient bidirectional tapped-inductor buck-boost converter, addressing high step-up and high step-down voltage conversion ratios, is proposed for energy harvesting applications based on DEAP generators. The high-side switch of the converter is replaced by a string of three non-matched, non-thermally-coupled, off-the-shelf MOSFETs, extending its effective operational range. Experiments conducted on a standalone DEAP generator validate the applicability of the proposed converter by demonstrating energy harvesting of 0.42 J, at 0.75 Hz and 60 % delta-strain, characterized by a world-first; energy density equal to 2 J per kg of active material.

Dimopoulos, Emmanouil; Munk-Nielsen, Stig

2014-01-01

396

International Nuclear Information System (INIS)

An analog implementation of a novel fixed-frequency quasi-sliding-mode controller for single-inductor dual-output (SIDO) buck converter in pseudo-continuous conduction mode (PCCM) with a self-adaptive freewheeling current level (SFCL) is presented. Both small and large signal variations around the operation point are considered to achieve better transient response so as to reduce the cross-regulation of this SIDO buck converter. Moreover, an internal integral loop is added to suppress the steady-state regulation error introduced by conventional PWM-based sliding mode controllers. Instead of keeping it as a constant value, the free-wheeling current level varies according to the load condition to maintain high power efficiency and less cross-regulation at the same time. To verify the feasibility of the proposed controller, an SIDO buck converter with two regulated output voltages, 1.8 V and 3.3 V, is designed and fabricated in HEJIAN 0.35 ?m CMOS process. Simulation and experiment results show that the transient time of this SIDO buck converter drops to 10 ?s while the cross-regulation is reduced to 0.057 mV/mA, when its first load changes from 50 to 100 mA. (semiconductor integrated circuits)

397

An analog implementation of a novel fixed-frequency quasi-sliding-mode controller for single-inductor dual-output (SIDO) buck converter in pseudo-continuous conduction mode (PCCM) with a self-adaptive freewheeling current level (SFCL) is presented. Both small and large signal variations around the operation point are considered to achieve better transient response so as to reduce the cross-regulation of this SIDO buck converter. Moreover, an internal integral loop is added to suppress the steady-state regulation error introduced by conventional PWM-based sliding mode controllers. Instead of keeping it as a constant value, the free-wheeling current level varies according to the load condition to maintain high power efficiency and less cross-regulation at the same time. To verify the feasibility of the proposed controller, an SIDO buck converter with two regulated output voltages, 1.8 V and 3.3 V, is designed and fabricated in HEJIAN 0.35 ?m CMOS process. Simulation and experiment results show that the transient time of this SIDO buck converter drops to 10 ?s while the cross-regulation is reduced to 0.057 mV/mA, when its first load changes from 50 to 100 mA.

Xiaobo, Wu; Qing, Liu; Menglian, Zhao; Mingyang, Chen

2013-01-01

398

Development of a state feedback controller for the synchronouns buck converter

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: English Abstract in english A digital control algorithm for a current-mode (CM) and a voltage-mode (VM) synchronous buck converter (SBC) is developed. In both cases, the design leads to a stable controller, even for a duty cycle larger than 50%. The desired output voltage and the transient response can be independently specifi [...] ed. Moreover, zero steady-state error in the output voltage can be obtained with the aid of additional dynamics. In both cases, the specification is done by pole placement using complete state feedback. A discrete-time model is used to design the feedback gains. Both the stability and the small-signal transient response are analyzed. In another paper (Oliva et al., 2003) the control algorithms are experimentally validated with a DSP-controlled SBC.

A., Oliva; H., Chiacchiarini; G., Bortolotto.

2005-04-01

399

An experimental 100W 1000V dc-dc converter using a capacitor diode voltage multipler (CDVM) with a nominal frequency of 100 kHz is studied. A component weight of about 1 kg/kW was obtained. Design equations for current, output -ripple and -power, efficiency and output voltage are derived. Agreement between experimental results and calculations is fairly good except for ripple.

Harrigill, W. T., Jr.; Myers, I. T.

1974-01-01

400

A High Step-Down Interleaved Buck Converter with Active-Clamp Circuits for Wind Turbines

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a high step-down interleaved buck coupled-inductor converter (IBCC with active-clamp circuits for wind energy conversion has been studied. In high step-down voltage applications, an IBCC can extend duty ratio and reduce voltage stresses on active switches. In order to reduce switching losses of active switches to improve conversion efficiency, a IBCC with soft-switching techniques is usually required. Compared with passive-clamp circuits, the IBCC with active-clamp circuits have lower switching losses and minimum ringing voltage of the active switches. Thus, the proposed IBCC with active-clamp circuits for wind energy conversion can significantly increase conversion efficiency. Finally, a 240 W prototype of the proposed IBCC with active-clamp circuits was built and implemented. Experimental results have shown that efficiency can reach as high as 91%. The proposed IBCC with active-clamp circuits is presented in high step-down voltage applications to verify the performance and the feasibility for energy conversion of wind turbines.

Chih-Lung Shen

2012-12-01

401

Energy Technology Data Exchange (ETDEWEB)

This work presents the study and development of a processing power system that could be used in the connection of renewable energy sources to commercial power grid. The system consists of a ZETA converter associated with a bridge inverter operating at low frequency. The Zeta converter, operating in discontinuous conduction mode (DCM), plays the main role in this arrangement, producing a rectified sinusoidal current waveform synchronized with the electric grid. The function of the full-bridge inverter, connected in cascade with the Zeta converter, is to reverse every 180 deg the current generated by the Zeta converter. Initially it presents the analysis of the Zeta converter operating in DCM, as well as a design criterion. Following by the control strategy and the experimental results for the proposed system are presented and discussed. (author)

Lopez, Henrique Fioravanti Miguel

2009-08-15

402

An efficiency improved single-phase PFC converter for electric vehicle charger applications

DEFF Research Database (Denmark)

This paper presents an efficiency improved single-phase power factor correction (PFC) converter with its target application to plug-in hybrid electric vehicle (PHEV) charging systems. The proposed PFC converter features sinusoidal input current, three-level output characteristic, and wide range of output DC voltage. Moreover, the involved DC/DC buck conversion stage may only need to convert partial input power rather than full scale of input power, and therefore the system overall efficiency can be much improved. Through proper control of the buck converter, it is also possible to mitigate the double-line frequency ripple power that is inherent in a single-phase AC/DC system. Both simulation and experimental results are presented to show the effectiveness of this converter.

Zhu, Dexuan; Tang, Yi

2013-01-01

403

Regenerative semi-active suspensions can capture the previously dissipated vibration energy and convert it to usable electrical energy for powering on-board electronic devices, while achieve both the better ride comfort and improved road handling performance at the same time when certain control is applied. To achieve this objective, the power electronics interface circuit connecting the energy harvester and the electrical loads, which can perform simultaneous vibration control and energy harvesting function is in need. This paper utilized a buck-boost converter for simultaneous semi-active vibration control and energy harvesting with electromagnetic regenerative shock absorber, which utilizes a rotational generator to converter the vibration energy to electricity. It has been found that when the circuit works in discontinuous current mode (DCM), the ratio between the input voltage and current is only related to the duty cycle of the switch pulse width modulation signal. Using this property, the buck-boost converter can be used to perform semi-active vibration control by controlling the load connected between the terminals of the generator in the electromagnetic shock absorber. While performing the vibration control, the circuit always draw current from the shock absorber and the suspension remain dissipative, and the shock absorber takes no additional energy to perform the vibration control. The working principle and dynamics of the circuit has been analyzed and simulations were performed to validate the concept.

Li, Peng; Zhang, Chongxiao; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

2014-04-01

404

A Single Phase to Three Phase PFC Half-Bridge Converter Using BLDC Drive with SPWM Technique.

In this paper, a buck half-bridge DC-DC converter is used as a single-stage power factor correction (PFC) converter for feeding a voltage source inverter (VSI) based permanent magnet brushless DC motor (BLDC) drive. The front end of this PFC converter is a diode bridge rectifier (DBR) fed from single-phase AC mains. The BLDC is used to drive a compressor load of an air conditioner through a three-phase VSI fed from a controlled DC link voltage. The speed of the compressor is controlled to ach...

Srinu Duvvada; Manmadha Kumar B

2014-01-01

405

DEFF Research Database (Denmark)

In this paper an analysis of two planar transformers designed for high-current switching applications is presented. Typical converter application is represented by fuel and electrolyser cell converters. The transformer designs are based on E+I and ER+I planar cores while the analysis focuses on winding resistance and leakage inductances which represent the main concerns related to low-voltage high-current applications. The PCB winding design has a one to one turn ratio with no interleaving between primary and secondary windings. The main goal was to determine if ER planar core could provide a significant advantage in terms of winding losses compared to planar E cores. Results from finite element analysis highlight that low frequency winding resistance is lower for the ER core since it is dominated by the lower mean turn length however, as the AC-resistance becomes dominating the winding eddy current losses increases more in the ER core than in the E core design. Calculated and simulated leakage inductances for the analyzed cores do not show relevant differences. A laboratory prototype based on E64 planar core is used as reference. Laboratory measurements highlight that FEM analysis provides more realistic results when computing the winding AC-resistance.

Pittini, Riccardo; Zhang, Zhe

2012-01-01

406

A tapped-inductor buck-boost converter for a multi-DEAP generator energy harvesting system

Interest on Dielectric ElectroActive Polymer (DEAP) generators has aroused among scientists in recent years, due to the former ones' documented advantages against competing electromagnetic and field-activated technologies. Yet, the need for bidirectional energy flow under high step-up and high step-down voltage conversion ratios, accompanied by low-average but relatively high-peak currents, imposes great challenges on the design of the employed power electronic converter. On top of that, the shortage of commercially-available, high-efficient, high-voltage, low-power semiconductor devices limits the effective operational range of the power electronic converter. In this paper, a bidirectional tapped-inductor buck-boost converter is proposed, addressing high- efficient high step-up and high step-down voltage conversion ratios, for energy harvesting applications based on DEAP generators. The effective operational range of the converter is extended, by replacing its high-side switch with a string of three serialized MOSFETs, to accommodate the need for high-efficient high-voltage operation. Experiments conducted on a single DEAP generator - part of a quadruple DEAP generator energy harvesting system with all elements installed sequentially in the same circular disk with a 90° phase shift - validate the applicability of the proposed converter, demonstrating energy harvesting of 0.26 J, at 0.5 Hz and 60% delta- strain; characterized by an energy density of 1.25 J per kg of active material.

Dimopoulos, Emmanouil; Munk-Nielsen, Stig

2014-03-01

407

A tapped-inductor buck-boost converter for a multi-DEAP generator energy harvesting system

DEFF Research Database (Denmark)

Interest on Dielectric ElectroActive Polymer (DEAP) generators has aroused among scientists in recent years, due to the former ones' documented advantages against competing electromagnetic and field-activated technologies. Yet, the need for bidirectional energy flow under high step-up and high step-down voltage conversion ratios, accompanied by low-average but relatively high-peak currents, imposes great challenges on the design of the employed power electronic converter. On top of that, the shortage of commercially-available, high-efficient, high-voltage, low-power semiconductor devices limits the effective operational range of the power electronic converter. In this paper, a bidirectional tapped-inductor buck-boost converter is proposed, addressing high-efficient high step-up and high step-down voltage conversion ratios, for energy harvesting applications based on DEAP generators. The effective operational range of the converter is extended, by replacing its high-side switch with a string of three serialized MOSFETs, to accommodate the need for high-efficient high-voltage operation. Experiments conducted on a single DEAP generator - part of a quadruple DEAP generator energy harvesting system with all elements installed sequentially in the same circular disk with a 90 phase shift - validate the applicability of the proposed converter, demonstrating energy harvesting of 0.26 J, at 0.5 Hz and 60 % delta-strain; characterized by an energy density of 1.25 J per kg of active material.

Dimopoulos, Emmanouil; Munk-Nielsen, Stig

2014-01-01

408

Exploration of Charge Recycling DC-DC Conversion Using a Switched Capacitor Regulator

Directory of Open Access Journals (Sweden)

Full Text Available The increasing popularity of DVFS (dynamic voltage frequency scaling schemes for portable low power applications demands highly efficient on-chip DC-DC converters. The primary aim of this work is to enable increased efficiency of on-chip DC-DC conversion for near-threshold operation of multicore chips. The idea is to supply nominal (high off-chip voltage to the cores which are then “voltage-stacked” to generate the near-threshold (low voltages based on Kirchhoff’s voltage law through charge recycling. However, the effectiveness of this implicit down-conversion is affected by the current imbalance among the cores. The paper presents a design methodology and optimization strategy for highly efficient charge recycling on-chip regulation using a push-pull switched capacitor (SC circuit. A dual-boundary hysteretic feedback control circuit has been designed for stacked loads. A stacked-voltage domain with its self-regulation capability combined with a SC converter has shown average efficiency of 78%–93% for 2:1 down-conversion with ILoad (max of 200 mA and workload imbalance varying from 0–100%.

Mircea R. Stan

2013-07-01

409

Stability Constrained Efficiency Optimization for Droop Controlled DC-DC Conversion System

DEFF Research Database (Denmark)

Paralleled dc converter systems are widely used in distribution systems and uninterruptable power supplies. This paper implements a hierarchical control in a droop-controlled dc-dc conversion system with special focus on improving system efficiency which is dealt within the tertiary regulation. As the efficiency of each converter changes with output power, virtual resistances (VRs) are set as decision variables for adjusting power sharing proportion among converters. It is noteworthy that apart from restoring the voltage deviation, secondary control plays an important role to stabilize dc bus voltage when implementing tertiary regulation. Moreover, system dynamic is affected when shifting VRs. Therefore, the stability is considered in optimization by constraining the eigenvalues arising from dynamic state space model of the system. Genetic algorithm is used in searching for global efficiency optimum while keeping stable operation. Simulation results are shown to demonstrate the effectiveness of the method.

Meng, Lexuan; Dragicevic, Tomislav

2013-01-01

410

Liquid Nitrogen Temperature Operation of a Switching Power Converter

The performance of a 42/28 V, 175 W, 50 kHz pulse-width modulated buck dc/dc switching power converter at liquid nitrogen temperature (LNT) is compared with room temperature operation. The power circuit as well as the control circuit of the converter, designed with commercially available components, were operated at LNT and resulted in a slight improvement in converter efficiency. The improvement in power MOSFET operation was offset by deteriorating performance of the output diode rectifier at LNT. Performance of the converter could be further improved at low temperatures by using only power MOSFET's as switches. The use of a resonant topology will further improve the circuit performance by reducing the switching noise and loss.

Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

1995-01-01

411

A Closed Form Expression for Predicting Fast Scale Instability in Switching Buck Converters

Directory of Open Access Journals (Sweden)

Full Text Available Fast scale instability is an undesired phenomenon in switching converters. In past studies, its prediction has been mainly carried out by deriving discrete time models and then linearizing the system in the vicinity of a fixed point. However, the results obtained from such an approach cannot be applied for design purpose except for simple cases of current mode control. Alternatively, in this paper, this phenomenon is analyzed by using a unified formal symbolic approach which can be applied for different control strategies. This approach is based on expressing the condition for fast scale instability occurrence using Fourier series and then converting the result into a matrix form expression which depends explicitly on the system parameters making the results directly applicable for design purpose. Under certain practical conditions concerning these parameters, the matrix form expression can be approximated by standard polynomial functions depending on the operating duty cycle. The approximating polynomial functions are widely related to the well known Clausen polynomial functions. The results presented in this work clearly generalize the well known stability condition of current mode control.

El Aroudi Abdelali

2012-07-01

412

DEFF Research Database (Denmark)

Research and development within piezoelectric transformer (PT) based converters are rapidly increasing as the technology is maturing and starts to prove its capabilities. Especially for high voltage and high step-up applications, PT based converters have demonstrated good performance and DC/AC converters are widely used commercially. The availability of PT based converters for DC/DC applications are very limited and are not that developed yet. I this paper an interleaved multi layer Rosen-type PT for high step-up and high output voltage is developed, for driving a 2.5kV dielectric electro active polymer actuator [17]. The targeted application utilises an inductor-less half-bridge driving topology, where the reward of eliminating the series inductor is a reduction in component count, size and price. The absence of a series inductance calls for other means to avoid large hard switching losses and obtain soft switching capabilities. This can be achieved by utilising an advantageous PT structure, which is the main advantage of the interleaved Rosen-type PT. Furthermore the design should be further optimised, in order to achieve soft switching capability. The goal of this paper is to develop a soft switching optimised PT, capable of generating output voltages higher than 2kV from a 24V supply voltage. Furthermore finite element method (FEM) has been the main tool through the PT development.

RØdgaard, Martin SchØler; Andersen, Thomas

2012-01-01

413

Directory of Open Access Journals (Sweden)

Full Text Available En este trabajo se estudia el comportamiento de un convertidor electrónico en configuración buck-boost. Elobjetivo del controlador es hacer el rastreo de señales sinusoidales usando un controlador con histéresiscero, es decir que el usuario pueda tener a la salida cualquier señal a un nivel más alto de potencia y conla característica que esta señal deseada es regulada variable en frecuencia, en amplitud y forma de onda.El controlador es rápido pues se comprobó en el laboratorio que ante perturbaciones en la carga y en laseñal de referencia, se comporta adecuadamente. Se implementó el convertidor usando un inversormonofásico en configuración de medio puente y se controla el sistema con un prototipo rápido de control(RCP DS1104 en tiempo real. In this work, we analysed the behaviour of a buck-boost electronic converter. The objective of the zerohysteresis controller is to track user defined sinusoidal signals, usually featuring high power level andvariable frequency, amplitude and wave form. The controller was implemented in the laboratory, whereload and reference signal disturbances were introduced. The controller achieved a fast and adequatebehaviour. The converter was implemented using a half bridge monophasic inverter, and a rapid controlprototyping (RCP DS1104 in real time for the control task.

Fredy Edimer Hoyos Velasco

2011-02-01

414

We propose a way of achieving maximum power and power-transfer efficiency from thermoelectric generators by optimized selection of maximum-power-point-tracking (MPPT) circuits composed of a boost-cascaded-with-buck converter. We investigated the effect of switch resistance on the MPPT performance of thermoelectric generators. The on-resistances of the switches affect the decrease in the conversion gain and reduce the maximum output power obtainable. Although the incremental values of the switch resistances are small, the resulting difference in the maximum duty ratio between the input and output powers is significant. For an MPPT controller composed of a boost converter with a practical nonideal switch, we need to monitor the output power instead of the input power to track the maximum power point of the thermoelectric generator. We provide a design strategy for MPPT controllers by considering the compromise in which a decrease in switch resistance causes an increase in the parasitic capacitance of the switch.

Park, Hyunbin; Sim, Minseob; Kim, Shiho

2015-01-01

415

Development of Buck-Type Single-Phase to Three-Phase Power Converter with Active Buffer

This paper proposes a novel single-phase to three-phase power converter that can reduce the capacitance value of the smoothing capacitor in the DC link part. In the case of the single-phase converter, a large smoothing capacitor is required to absorb a power ripple with a frequency twice that of the power supply. The proposed method involves the use of an indirect matrix converter with an active snubber to absorb the power ripple. Therefore, the proposed system does not require a reactor and large energy buffer, such as a smoothing capacitor. Moreover, a diode bridge can be used on the rectifier stage in the proposed circuit. In this paper, the basic operation and validity of the proposed method are confirmed by simulation and experiment result. Thus, it is confirmed that good waveforms for input and output currents can be obtained by the proposed method.

Ohnuma, Yoshiya; Itoh, Jun-Ichi

416

ZVS Operating Region of Multiresonant DC/DC Boost Conveter

Directory of Open Access Journals (Sweden)

Full Text Available Electromagnetic phenomena that occur during stable operation in resonant circuits of multiresonant ZVS boost converter are described, which can be applied in many fields of the needs of DC voltage electricity. The operating region of the converter is defined which assures the circuit’s operation in which semiconductor elements are switched at zero voltage (ZVS. Conditions delimiting the ZVS operating region are provided. Analysis of the circuit’s operation is based on results of simulation testing by means of Simplorer software.

Elzbieta Szychta

2007-01-01

417

This book is devoted to resonant energy conversion in power electronics. It is a practical, systematic guide to the analysis and design of various dc-dc resonant inverters, high-frequency rectifiers, and dc-dc resonant converters that are building blocks of many of today's high-frequency energy processors. Designed to function as both a superior senior-to-graduate level textbook for electrical engineering courses and a valuable professional reference for practicing engineers, it provides students and engineers with a solid grasp of existing high-frequency technology, while acquainting them wit

Kazimierczuk, Marian K

2012-01-01

418

A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.

Zhu, Lizhi (Canton, MI)

2007-11-13

419

The distributed renewable energy generation and utilization are constantly growing, and are expected to be integrated with the conventional grid. The growing pressure for innovative solutions will demand power electronics to take an even larger role in future electric energy delivery and management systems, since power electronics are required for the conversion and control of electric energy by most dispersed generation systems Furthermore, power electronics systems can provide additional intelligent energy management, grid stability and power quality capabilities. Medium-voltage isolated dc-dc converter will become one of the key interfaces for grid components with moderate power ratings. To address the demand of medium voltage (MV) and high power capability for future electric energy delivery and management systems, the power electronics community and industry have been reacting in two different ways: developing semiconductor technology or directly connecting devices in series/parallel to reach higher nominal voltages and currents while maintaining conventional converter topologies; and by developing new converter topologies with traditional semiconductor technology, known as multilevel converters or modular converters. The modular approach uses the well-known, mature, and cheaper power semiconductor devices by adopting new converter topologies. The main advantages of the modular approach include: significant improvement in reliability by introducing desired level of redundancy; standardization of components leading to reduction in manufacturing cost and time; power systems can be easily reconfigured to support varying input-output specifications; and possibly higher efficiency and power density of the overall system. Input-series output-parallel (ISOP) modular configuration is a good choice to realize MV to low voltage (LV) conversion for utility application. However, challenges still remain. First of all, for the high-frequency MV utility application, the low switching loss and conduction loss are must-haves for high efficiency, while bidirectional power flow capability is a must for power management requirement. To address the demand, the phase-shift dual-halfbridge (DHB) is proposed as the constituent module of ISOP configuration for MV application. The proposed ISOP DHB converter employs zero-voltage-switching (ZVS) technique combined with LV MOSFETs to achieve low switching and conduction losses under high frequency operation, and therefore high efficiency and high power density, and bidirectional power flow as well. Secondly, a large load range of high efficiency is desired rather than only a specific load point due to the continuous operation and large load variation range of utility application, which is of high importance because of the rising energy cost. This work proposes a novel DHB converter with an adaptive commutation inductor. By utilizing an adaptive inductor as the main energy transfer element, the output power can be controlled by not only the phase shift but also the commutation inductance, which allows the circulating energy to be optimized for different load conditions to maintain ZVS under light load conditions and minimize additional conduction losses under heavy load conditions as well. As a result, the efficiency at both light and heavy load can be significantly improved compared with the conventional DHB converter, and therefore extended high-efficiency range can be achieved. In addition, current stress of switch devices can be reduced. The theoretical analysis is presented and validated by the experimental results on a 50 kHz, 1 kW dc-dc converter module. Thirdly, input-voltage sharing and output-current sharing are critical to assure the advantages of the ISOP modular configuration. To solve this issue, an identically distributed control scheme is proposed in this work. The proposed control scheme, using only one distributed voltage loop to realize both input-voltage and output-current sharing, provides plug-and-play capability, possible high-level fault tolerance, and easy implementatio

Fan, Haifeng

2011-12-01

420

New Architectures for Radio-Frequency DC-DC Power Conversion

This document proposes two new architectures for switched-mode dc–dc power conversion. The proposed architectures enable dramatic increases in switching frequency to be realized while preserving features critical in practice, including regulation of the output across a wide load range and high light-load efficiency. This is achieved in part by how the energy conversion and regulation functions are partitioned. The structure and control approach of the new architectures are described, along ...

Rivas, Juan M.; Shafran, John S.; Perreault, David J.; Wahby, Riad S.

2005-01-01

421

An Integrated Onboard Charger and Accessary Power Converter for Plug-in Electric Vehicles

Energy Technology Data Exchange (ETDEWEB)

Abstract: In this paper, an integrated onboard battery charger and accessary dc-dc converter for plug-in electric vehicles (PEVs) is presented. The idea is to utilize the already available traction drive inverters and motors of a PEV as the frond converter of the charger circuit and the transformer of the 14 V accessary dc-dc converter to provide galvanic isolation. The topology was verified by modeling and experimental results on a 5 kW charger prototype

Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

2013-01-01

422

International Nuclear Information System (INIS)

The instantaneous luminosity of the LHC is expected to reach 2 x 1034 s-1cm-2 and 5 x 1034 s-1cm-2 around the years 2019 and 2024, respectively. After the second upgrade the LHC will be referred to as the High Luminosity LHC (HL-LHC). In order to benefit from the higher luminosities, CMS foresees to upgrade its pixel detector during an extended winter shutdown of the LHC at the end of 2016 and the beginning of 2017. During a long shutdown of the LHC over the years 2022 and 2023, it is foreseen to install a completely new tracking system in CMS. Both upgrades are expected to result in the need to provide more electric current to the detector. However, power losses in cables already contribute 50% to the power consumption of the present tracker and rise with the current squared. Since no more space is available for cables, and thicker cables within the tracking volume spoil the material budget of the detector, new powering schemes are considered mandatory. CMS foresees the use of radiation tolerant DC-DC converters on the front-end to reduce power losses on cables. This thesis describes the new powering scheme of the CMS pixel detector and discusses the options with respect to a new strip tracker. A radiation and magnetic field tolerant DC-DC converter prototype, the PIXV8A, is introduced and the research that led to its development is summarised. The PIXV8A has been developed for the application in the pixel upgrade and is also a first approach for a DC-DC converter for the later upgrade of the CMS tracking system. The PIXV8A makes use of the AMIS4 chip, which has been proven to stay operational for total ionising doses of up to 1 MGy and fluences of up to 1015 neq/cm2. With an input voltage of 10 V, the PIXV8A converter provides an efficiency of about 80% for output voltages of 2.5 V and 3.0 V. Within this thesis the robustness of the novel powering scheme and the qualification of the PIXV8A are demonstrated in several tests, including system test measurements with silicon strip detector modules and silicon pixel detector modules in combination with an evaporative CO2 cooling system.

423

Energy Technology Data Exchange (ETDEWEB)

The instantaneous luminosity of the LHC is expected to reach 2 x 10{sup 34} s{sup -1}cm{sup -2} and 5 x 10{sup 34} s{sup -1}cm{sup -2} around the years 2019 and 2024, respectively. After the second upgrade the LHC will be referred to as the High Luminosity LHC (HL-LHC). In order to benefit from the higher luminosities, CMS foresees to upgrade its pixel detector during an extended winter shutdown of the LHC at the end of 2016 and the beginning of 2017. During a long shutdown of the LHC over the years 2022 and 2023, it is foreseen to install a completely new tracking system in CMS. Both upgrades are expected to result in the need to provide more electric current to the detector. However, power losses in cables already contribute 50% to the power consumption of the present tracker and rise with the current squared. Since no more space is available for cables, and thicker cables within the tracking volume spoil the material budget of the detector, new powering schemes are considered mandatory. CMS foresees the use of radiation tolerant DC-DC converters on the front-end to reduce power losses on cables. This thesis describes the new powering scheme of the CMS pixel detector and discusses the options with respect to a new strip tracker. A radiation and magnetic field tolerant DC-DC converter prototype, the PIXV8A, is introduced and the research that led to its development is summarised. The PIXV8A has been developed for the application in the pixel upgrade and is also a first approach for a DC-DC converter for the later upgrade of the CMS tracking system. The PIXV8A makes use of the AMIS4 chip, which has been proven to stay operational for total ionising doses of up to 1 MGy and fluences of up to 10{sup 15} n{sub eq}/cm{sup 2}. With an input voltage of 10 V, the PIXV8A converter provides an efficiency of about 80% for output voltages of 2.5 V and 3.0 V. Within this thesis the robustness of the novel powering scheme and the qualification of the PIXV8A are demonstrated in several tests, including system test measurements with silicon strip detector modules and silicon pixel detector modules in combination with an evaporative CO{sub 2} cooling system.

Sammet, Jan

2014-03-18

424

The book contains the contribution of 18 tutorials of the 20th workshop on Advances in Analog Circuit Design. Each part discusses a specific to-date topic on new and valuable design ideas in the area of analog circuit design. Each part is presented by six experts in that field and state of the art information is shared and overviewed. This book is number 20 in this successful series of Analog Circuit Design, providing valuable information and excellent overviews of Low-Voltage Low-Power Data Converters - Chaired by Prof. Anderea Baschirotto, University of Milan-Bicocca Short Range Wireless Front-Ends - Chaired by Prof. Arthur van Roermund, Eindhoven University of Technology Power management and DC-DC - Chaired by Prof. M. Steyaert, Katholieke University Leuven Analog Circuit Design is an essential reference source for analog circuit designers and researchers wishing to keep abreast with the latest development in the field. The tutorial coverage also makes it suitable for use in an advanced design.

Roermund, Arthur; Baschirotto, Andrea

2012-01-01

425

Recovery Act: Integrated DC-DC Conversion for Energy-Efficient Multicore Processors

Energy Technology Data Exchange (ETDEWEB)

In this project, we have developed the use of thin-film magnetic materials to improve in energy efficiency of digital computing applications by enabling integrated dc-dc power conversion and management with on-chip power inductors. Integrated voltage regulators also enables fine-grained power management, by providing dynamic scaling of the supply voltage in concert with the clock frequency of synchronous logic to throttle power consumption at periods of low computational demand. The voltage converter generates lower output voltages during periods of low computational performance requirements and higher output voltages during periods of high computational performance requirements. Implementation of integrated power conversion requires high-capacity energy storage devices, which are generally not available in traditional semiconductor processes. We achieve this with integration of thin-film magnetic materials into a conventional complementary metal-oxide-semiconductor (CMOS) process for high-quality on-chip power inductors. This project includes a body of work conducted to develop integrated switch-mode voltage regulators with thin-film magnetic power inductors. Soft-magnetic materials and inductor topologies are selected and optimized, with intent to maximize efficiency and current density of the integrated regulators. A custom integrated circuit (IC) is designed and fabricated in 45-nm CMOS silicon-on-insulator (SOI) to provide the control system and power-train necessary to drive the power inductors, in addition to providing a digital load for the converter. A silicon interposer is designed and fabricated in collaboration with IBM Research to integrate custom power inductors by chip stacking with the 45-nm CMOS integrated circuit, enabling power conversion with current density greater than 10A/mm2. The concepts and designs developed from this work enable significant improvements in performance-per-watt of future microprocessors in servers, desktops, and mobile devices. These new approaches to scaled voltage regulation for computing devices also promise significant impact on electricity consumption in the United States and abroad by improving the efficiency of all computational platforms. In 2006, servers and datacenters in the United States consumed an estimated 61 billion kWh or about 1.5% of the nation's total energy consumption. Federal Government servers and data centers alone accounted for about 10 billion kWh, for a total annual energy cost of about $450 million. Based upon market growth and efficiency trends, estimates place current server and datacenter power consumption at nearly 85 billion kWh in the US and at almost 280 billion kWh worldwide. Similar estimates place national desktop, mobile and portable computing at 80 billion kWh combined. While national electricity utilization for computation amounts to only 4% of current usage, it is growing at a rate of about 10% a year with volume servers representing one of the largest growth segments due to the increasing utilization of cloud-based services. The percentage of power that is consumed by the processor in a server varies but can be as much as 30% of the total power utilization, with an additional 50% associated with heat removal. The approaches considered here should allow energy efficiency gains as high as 30% in processors for all computing platforms, from high-end servers to smart phones, resulting in a direct annual energy savings of almost 15 billion kWh nationally, and 50 billion kWh globally. The work developed here is being commercialized by the start-up venture, Ferric Semiconductor, which has already secured two Phase I SBIR grants to bring these technologies to the marketplace.

Shepard, Kenneth L

2013-03-31

426

Analysis and design of multicell DC/DC converters using vectorized models

Shows how the concepts of vectorization and design masks can be used to help the designer in comparing different designs and making the right choices. The book addresses series and parallel multicell conversion directly, and the concepts can be generalized to describe other topologies.

Meynard, Thierry

2015-01-01

427

Performance analysis of reverse recovery minimization effects in DC/DC converter using PSpice

Energy Technology Data Exchange (ETDEWEB)

Diodes play a significant role in many power electronic such as freewheeling and/or snubber components. In order to reduce the overall power loss of the circuit, many design features are required for the diode. Therefore, fast switching and fast recovery power diode have been developed for use the design. One of the circuit losses is due to reverse recovery current of the power diode, which affects performance of the power systems in terms of switching losses and noises. By reducing the reverse recovery current, the power loss of the power diode will also be reduced. In order to reduce the power loss in the circuit, this paper investigated the minimization of the reverse recovery effects in the power diode. An inductive chopper circuit using a CoolMOS power switch was set up to serve as the platform for investigation. The paper presented how the variations of the parameter's values in the inductive load chopper circuit affected the diode's reverse recovery characteristics. The parameters that were considered in the study included the gate drive, duty ratio, CoolMOS switching frequency, and operating temperature. In order to investigate the impact of each parameter on the reverse recovery effects, a PSpice device simulation model using a power diode was utilized. It was concluded that the switching frequency affected the total energy losses more significantly than factors of temperature, gate resistance and the duty ratio. 8 refs., 4 tabs., 10 figs.

Yahaya, N.Z.; Heng, D.K.; Wen, L.H.; Ng, A. [Petronas Technological Univ., Tronoh, Perak Darul Ridzuan (Malaysia)

2007-07-01

428

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the conception, fabrication and characterization of integrated inductors containing magnetic layers. We require different steps of micro-technologies: preparation of glass and ferrite substrates, RF sputtering, photolithography, etching and finally electroplating techniques for copper and gold films. The geometrical magnitudes are determined by using HFSS simulator software. The measurements performed at low and high frequencies (up to 1 GHz permit to verify the correlation between experiment and simulation results. The inductance of the manufactured spiral inductor is ??about 200 nH and it is constant from low frequency up to 0.9 GHz.

Ali Siblini

2012-08-01

429

A heavy duty vehicle looses approximately 30-40 % of the energy in the fuel as waste heat through the exhaust system. Recovering this waste heat would make the vehicle meet the legislative and market demands of emissions and fuel consumption easier. This recovery is possible by transforming the waste heat to electric power using a thermoelectric generator. However, the thermoelectric generator electric characteristics makes direct usage of it unprotable, thus an electric power conditioner is ...

Jahanbakhsh, David

2012-01-01

430

A DC-DC Converter-Based PEM Fuel Cell System Emulator

The Proton Exchange Membrane Fuel Cell (PEMFC) is being investigated as an alternate power source for various applications as transportation and emergency power supplies. Fuel cell systems are characterized by high costs and complex auxiliary devices. For this reason, a fuel cell emulator can be used as a suitable and economic alternative to a real one for developing and testing a fuel cell power conditioning system. The fuel cell emulator must be able to reproduce the FC nonlinear output vol...

Rezzak, Daoud; Khoucha, Farid; Benbouzid, Mohamed; Kheloui, Abdelaziz; Mamoune, Abdeslam

2011-01-01

431

Multifunctional Converter Drive for Automotive Electric Power Steering Systems:

In this thesis it is shown that in the case of an automotive electric power steering system, critical pulse power loads can be decoupled from the power net with a storage element and a multifunctional converter. A multifunctional converter system is proposed because it uses the motor drive system as a dc-dc converter and hence no additional front-end dc-dc converter is required. The influence of a multifunctional converter to the torque and losses in induction and PM synchronous machines were...

Hackner, T. J.

2013-01-01

432

Sliding mode control for switched mode power supplies

Energy Technology Data Exchange (ETDEWEB)

Control applications of switched mode power supplies have been widely investigated. The main objective of research and development (R and D) in this field is always to find the most suitable control method to be implemented in various DC/DC converter topologies. In other words, the goal is to select a control method capable of improving the efficiency of the converter, reducing the effect of disturbances (line and load variation), lessening the effect of EMI (electro magnetic interference), and being less effected by component variation. The main objective of this research work is to study different control methods implemented in switched mode power supplies namely (PID control, hysteresis control, adaptive control, current programmed control, variable structure control (VSC), and sliding mode control (SMC). The advantages and drawbacks of each control method are given. Two control methods, the PID and the SMC are selected and their effects on DC/DC (Buck, Boost, and Buck-Boost) converters are examined. Matlab/Simulink is used to implement PID control method in DC/DC Buck converter and SMC in DC/DC (Buck, and Buck Boost) converters. For the prototype, operational amplifiers (op- amps) are used to implement PID control in DC/DC Buck converter. For SMC op-amps are implemented in DC/DC Buck converter and dSPACE is used to control the DC/DC Buck-Boost converter. The SMC can be applied to the DC/DC (Buck, Boost, and Buck-Boost) converters. A comparison of the effects of the PID control and the SMC on the DC/DC Buck converter response in steady state, under line variations, load variations, and different component variations is performed. Also the Conducted RF-Emissions between the PID and SMC DC/DC Buck Converter are compared. The thesis shows that, in comparison with the PID control, the SMC provides better steady-state response, better dynamic response, less EMI, inherent order reduction, robustness against system uncertainty disturbances, and an implicit stability proof. Giving a better steady-state and dynamic response, the SMC is implemented in a DC/DC resonant converter. The half-wave zero current switching (HWZCS) DC/DC Buck converter is selected as a converter topology. A general guideline to select the tank component values, needed for the designing of a HWZCS DC/DC Buck, is obtained. The implementation of the SMC to a HWZCS DC/DC Buck converter is analysed. The converter response is investigated in the steady-state region and in the dynamic region. (orig.)

Ahmed, M.

2004-07-01

433

Analysis and Design of Embedded Controlled Parallel Resonant Converter

Directory of Open Access Journals (Sweden)

Full Text Available Microcontroller based constant frequency controlled full bridge LC parallel resonant converter is presented in this paper for electrolyser application. An electrolyser is a part of renewable energy system which generates hydrogen from water electrolysis. The DC power required by the electrolyser system is supplied by the DC-DC converter. Owing to operation under constant frequency, the filter designs are simplified and utilization of magnetic components is improved. This converter has advantages like high power density, low EMI and reduced switching stresses. DC-DC converter system is simulated using MATLAB, Simulink. Detailed simulation results are presented. The simulation results are compared with the experimental results.

P. CHANDRASEKHAR

2009-07-01

434

Dynamic Characteristics of CUK Converter based on Sliding Mode Control

In this study the output voltage is controlled by the Cuk converter using Sliding Mode Control. Here to highlight the advantages of SMC, the PI controller is used in Cuk converter to control the output voltage and it is compared with the SMC. The PI and SMC is implemented in the DC-DC converter and the study is carried in MATLAB SIMULINK. The effect of SMC on the DC-DC converter response in steady state, under line variations, load variations and different component variations will be compare...

Sriranjani, R.; Nalini, D.; Jayalalitha, S.

2013-01-01

435

Design of Soft Switching Interleaved Boost Converter for Photovoltaic Application

Directory of Open Access Journals (Sweden)

Full Text Available The objective of our study is to reduce the size of passive components and reduction of ripple in output voltage and input current by using interleaved soft switching dc-dc converter (interleaving action. The PV system converts solar energy into electrical energy but its output varies with variation of solar radiation and temperature. To provide impedance matching between PV and load a dc-dc converter with MPPT technique is used in PV (Photo Voltaic Systems. This study incorporates design of the interleaved soft switching dc-dc converter for PV System by using P&O (Perturb and Observe fuzzy logic controller. The P&O Fuzzy MPPT provides an accurate and fast converging under varying illumination and load conditions compared to conventional MPPT methods. The performance of the system is first analyzed by simulation using Matlab/Simulink software. The results of simulation we