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1

It is difficult to obtain a large input/output voltage ratio with a dc-dc converter, because the duty factor d may not reach very small values. For the same reason, it is difficult to obtain an output voltage that is adjustable in a large range. A dc-dc converter circuit is proposed that overcomes this limitation by performing a voltage ratio d2/(1 - d) in the best operating mode. Circuit operation is analyzed, operating modes are evidenced, and the voltage ratio is deduced in each operating mode as a function of output current, duty factor, and circuit component values. Boundary conditions between different operating modes are obtained; consequently, it is concluded that these conditions do not occur for some operating modes. Finally, component ratings are summarized, to facilitate circuit design. The buck-flyback dc-dc converter is very suitable for low-voltage (e.g., computer) power supplies and for power supplies with the output voltage (adjustable in a large range) supplied from the mains without a mains voltage transformer.

Birca-Galateanu, Serban

1988-11-01

2

FRACTIONAL ORDER SMC FOR DC-DC BUCK CONVERTER

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

3

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

4

Buck-boost DC-DC converter with fractional control

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper deals with the fractional modeling of a DC-DC buck-boost converter, suitable in solar-powered electrical generation systems, and the design of a fractional controller for the aforementioned switching converter. Although the modeling and design of the controller is carried out for this particular DC-DC converter, it can be easily extended to other kind of switching converter. In addition, the comparison between integer-order plant/controller and fractional-order plants/controller is...

Marti?nez Garci?a, Herminio; Grau Saldes, Antoni; Bolea Monte, Yolanda; Marti?nez Gonza?lez, Rube?n

2011-01-01

5

Hybrid posicast controller for a DC-DC buck converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new Posicast compensated hybrid controller for the DC-DC Buck converter is investigated. Posicast is a feed forward compensator, which eliminates the overshoot in the step response of a lightly damped system. However, the traditional method is sensitive to variations in natural frequency. The new method described here reduces this undesirable sensitivity by using Posicast within the feedback loop. Design of the Posicast function is independent of computational delay. The new controller resu...

Kaithamalai Udhayakumar; Ponnusamy Lakshmi; Kandasamy Boobal

2008-01-01

6

Intelligent control of DC/DC switching buck converter

Energy Technology Data Exchange (ETDEWEB)

In this report, Neural-Fuzzy and Sliding-Mode control based Intelligent methods have been applied to DC/DC Converter. The focus is on DCIDC buck converter with equivalent series resistors operating in voltage mode. The usual method in controller design for this kind of converter is based on linear theory: The dynamics of the inherently nonlinear converter is approximated by linear systems e.g. using small-signal models. and then classical linear control methods have been used to design a controller. The goal of this work is to obtain intelligent and robust controllers using information only from output voltage of the converter (under line and load disturbances). The methods used are (i) Neural-Fuzzy Control using Radial Basis Function Network and (ii) Sliding Mode Control. Our investigations resulted in a robust controller structure consisting of Sliding Mode Controller and Integral Controller being developed for the converter. The proposed controller gave the best performance being more robust for model inaccuracies and disturbances in comparison with neural-fuzzy controller and linear PID controller. On the other hand, the results obtained by Neural-Fuzzy control technique were not satisfactory, and therefore are not presented here. All simulations in this work use parameters from a real DC/DC buck converter. Accordingly, the algorithms can readily be implemented on a real DSP setup. (orig.)

Uykan, Z.

2000-07-01

7

Hybrid posicast controller for a DC-DC buck converter

Directory of Open Access Journals (Sweden)

Full Text Available A new Posicast compensated hybrid controller for the DC-DC Buck converter is investigated. Posicast is a feed forward compensator, which eliminates the overshoot in the step response of a lightly damped system. However, the traditional method is sensitive to variations in natural frequency. The new method described here reduces this undesirable sensitivity by using Posicast within the feedback loop. Design of the Posicast function is independent of computational delay. The new controller results in a lower noise in the control signal, when compared to a conventional PID controller.

Kaithamalai Udhayakumar

2008-01-01

8

Digital Repository Infrastructure Vision for European Research (DRIVER)

Morcillo Bastidas, José Daniel (2012) Análisis y bifurcaciones de un convertidor buck dc-dc controlado por onda senoidal = Analysis and bifurcations of a dc-dc buck converter controlled by sine wave. Maestría thesis, Universidad Nacional de Colombia - Sede Manizales.

Morcillo Bastidas, Jose? Daniel

2012-01-01

9

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 asvo...

Trip, Nistor Daniel; Popescu, Viorel; Dudrik, Jaroslav

2010-01-01

10

Comparison and Simulation of Full Bridge and LCL-T Buck DC-DC Converter Systems

Digital Repository Infrastructure Vision for European Research (DRIVER)

The DC-DC Converter topologies have received increasing attention in recent years for Low power and high performance applications. The advantages DC-DC buck converters includes increased efficiency, reduced size, reduced EMI, faster transient response and improved reliability. The front end LCL-T in a buck converter is connected in sequence manner to improve the electrical performances and to reduce the switching losses. It futures several merits such as multi output capability and also will ...

Mallikarjuna Prasad, A.; Gururaj, B.; Sivanagaraju, S.

2012-01-01

11

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 start...

W.M.Utomo,; Z A Haron, A. A. Bakar

2011-01-01

12

Study of Sliding Mode Control of DC-DC Buck Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

13

Tri-State DC-DC Buck Converter with Efficient Conversion Ratio.

Digital Repository Infrastructure Vision for European Research (DRIVER)

In modern electronic applications the requirement of step down dc-dc conversion is much more. To estimate this process this dc-dc buck converter is implemented with perfect duty cycles as a proposed work. The converter comprises symmetrical half bridges and its structures. The voltage differences across two bridges has been examined in presented and balanced condition of operation is achieved. Then a modulation strategy which can satisfy the operation of the converter is proposed with the cap...

Yuvaraja, T.

2013-01-01

14

HIGH PERFORMANCE ALGORITHMS FOR THE CONTROL OF BUCK DC-DC CONVERTERS

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, two control methods are presented for controlling the DC-DC converters. These proposed control algorithms are tailored to buck DC-DC converter, so as to optimize the performance of the converter. First, a model predictive control (MPC) method which uses a short prediction horizon is proposed. Since a short prediction horizon is used, the optimization solution can be derived analytically so that the algorithm becomes simple enough and can be implemented on-line. Further, the ref...

ABU ZAHARIN AHMAD,; KANG-ZHI LIU; HARUKA KINOSHITA

2010-01-01

15

An LMI Approach to Stability Analysis of PWM DC-DC Buck Converters

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper considers a DC-DC buck power converter employing pulse width modulation and voltage feedback control. Global asymptotical stability of a periodical operating mode is examined. It is shown that the stability analysis can be reduced to study of a feasibility problem of semidefinite programming.

Churilov, Alexander N.

2006-01-01

16

Tri-State DC-DC Buck Converter with Efficient Conversion Ratio.

Directory of Open Access Journals (Sweden)

Full Text Available In modern electronic applications the requirement of step down dc-dc conversion is much more. To estimate this process this dc-dc buck converter is implemented with perfect duty cycles as a proposed work. The converter comprises symmetrical half bridges and its structures. The voltage differences across two bridges has been examined in presented and balanced condition of operation is achieved. Then a modulation strategy which can satisfy the operation of the converter is proposed with the capacitor voltages self balance, and the function of the output dc voltage Vo is deduced.

T.Yuvaraja

2013-11-01

17

A novel bidirectional multilevel boost-buck dc-dc converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

18

Design of Controllers for Single-Input Dual-Output Synchronous DC-DC Buck Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

Design and control techniques for a Single Input Dual Output (SIDO) Synchronous DC-DC Buck Converter are presented. The advantage of this converter eliminates one MOSFET switch and its drive circuitry when compared to the conventional converter and in this system both output voltages are generated by the same integrated power converter. A Genetic Algorithm assisted PI controller is designed to maintain the output voltages to a constant value against load and line variations and compared with ...

Augustilindiya, S.; Palani, S.; Vijayarekha, K.; Sreenath, V.

2013-01-01

19

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

20

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

21

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

22

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

23

A current-mode DC—DC buck converter with adaptive zero compensation

To achieve fast transient response for a DC—DC buck converter, an adaptive zero compensation circuit is presented. The compensation resistance is dynamically adjusted according to the different output load conditions, and achieves an adequate system phase margin under the different conditions. An improved capacitor multiplier circuit is adopted to realize the minimized compensation capacitance size. In addition, analysis of the small-signal model shows the correctness of the mechanism of the proposed adaptive zero compensation technique. A current-mode DC—DC buck converter with the proposed structure has been implemented in a 0.35 ?m CMOS process, and the die size is only 800 × 1040 ?m2. The experimental results show that the transient undershoot/overshoot voltage and the recovery times do not exceed 40 mV and 30 ?s for a load current variation from 100 mA to 1 A.

Ling, Yang; Guoding, Dai; Chongwei, Xu; Yuezhi, Liu

2013-08-01

24

A current-mode DC—DC buck converter with adaptive zero compensation

International Nuclear Information System (INIS)

To achieve fast transient response for a DC—DC buck converter, an adaptive zero compensation circuit is presented. The compensation resistance is dynamically adjusted according to the different output load conditions, and achieves an adequate system phase margin under the different conditions. An improved capacitor multiplier circuit is adopted to realize the minimized compensation capacitance size. In addition, analysis of the small-signal model shows the correctness of the mechanism of the proposed adaptive zero compensation technique. A current-mode DC—DC buck converter with the proposed structure has been implemented in a 0.35 ?m CMOS process, and the die size is only 800 × 1040 ?m2. The experimental results show that the transient undershoot/overshoot voltage and the recovery times do not exceed 40 mV and 30 ?s for a load current variation from 100 mA to 1 A. (semiconductor integrated circuits)

25

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

26

Controller Design of buck dc/dc converter using neural networks

International Nuclear Information System (INIS)

Nowadays, dc-dc topologies are widely utilized in many industrial applications due to their high efficiency, fast switching actions, low volume and weight and low cost. DC-DC converter is a big family of converters and consist more than thousand of topologies. Buck converter is one of the types of such family and only operates in the step-down mode. Such converter is highly under damped system and contains nonlinearities which lead to oscillations during operation. During last few decades various new control techniques have been investigated and analyzed in order to overcome the developed oscillation in output of this converter. Recently, NNCs (Neural Network Controllers) are gaining popularity in modeling, identification and control of power electronic converters. These controllers are advanced controllers and have fast dynamic behaviour and robustness. The NNCs are nonlinear controllers which enhance the system performance, increase system speed and reduce the system complexity. In this research work, NNCs are designed for Buck topology to minimize uncertainties. The operation of Buck topology with designed NNCs is analyzed during line and load variations and results are compared with results of PI (Proportional and Integral) controller.

27

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Kaoutar Elbakkar; Khadija Slaoui

2011-01-01

28

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 in both buck and boost modes of converter operation. Since this converter can operate over a wide input voltage range, it can be employed in power factor correction. The experimental results obtained from a 150W prototype circuit operating at 100KHz are presented to confirm the integrity of the proposed circuit.

Majid Delshad

2010-03-01

29

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

30

DC-DC buck converters for the CMS Tracker upgrade at SLHC

International Nuclear Information System (INIS)

The CMS experiment at the Large Hadron Collider (LHC) at CERN, Geneva, is planning major upgrades of its current pixel and strip detectors for the LHC luminosity upgrade, known as the SLHC. Due to the larger channel count and - in case of the strip tracker - increased functionality, the powering scheme adopted today, namely parallel powering of several detector modules, has to be abandoned. Instead, a powering scheme based on the DC-DC conversion technique is foreseen, which would lead to lower power losses in the supply cables, and would allow to reduce the material budget of cables and associated electronic boards in the sensitive detector volume. This paper deals with the development, characterisation and optimisation of DC-DC buck converter prototypes for the upgrades of the CMS pixel and strip detectors at the SLHC.

31

DC-DC buck converters for the CMS Tracker upgrade at SLHC

The CMS experiment at the Large Hadron Collider (LHC) at CERN, Geneva, is planning major upgrades of its current pixel and strip detectors for the LHC luminosity upgrade, known as the SLHC. Due to the larger channel count and — in case of the strip tracker — increased functionality, the powering scheme adopted today, namely parallel powering of several detector modules, has to be abandoned. Instead, a powering scheme based on the DC-DC conversion technique is foreseen, which would lead to lower power losses in the supply cables, and would allow to reduce the material budget of cables and associated electronic boards in the sensitive detector volume. This paper deals with the development, characterisation and optimisation of DC-DC buck converter prototypes for the upgrades of the CMS pixel and strip detectors at the SLHC.

Feld, L.; Jussen, R.; Karpinski, W.; Klein, K.; Sammet, J.

2011-01-01

32

DC-DC buck converters for the CMS Tracker upgrade at SLHC

Energy Technology Data Exchange (ETDEWEB)

The CMS experiment at the Large Hadron Collider (LHC) at CERN, Geneva, is planning major upgrades of its current pixel and strip detectors for the LHC luminosity upgrade, known as the SLHC. Due to the larger channel count and - in case of the strip tracker - increased functionality, the powering scheme adopted today, namely parallel powering of several detector modules, has to be abandoned. Instead, a powering scheme based on the DC-DC conversion technique is foreseen, which would lead to lower power losses in the supply cables, and would allow to reduce the material budget of cables and associated electronic boards in the sensitive detector volume. This paper deals with the development, characterisation and optimisation of DC-DC buck converter prototypes for the upgrades of the CMS pixel and strip detectors at the SLHC.

Feld, L; Jussen, R; Karpinski, W; Klein, K; Sammet, J, E-mail: Katja.Klein@cern.ch [1. Physikalisches Institut B, RWTH Aachen University, Sommerfeldstrasse 14, 52074 Aachen (Germany)

2011-01-15

33

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

34

Existence of horseshoe maps in current-mode controlled buck-boost dc/dc converters

International Nuclear Information System (INIS)

In this paper, a buck-boost dc/dc converter under a typical current-mode control is studied. The existence of chaos is proven theoretically in this system. The proof consists of showing that the dynamics of the system is semiconjugate to that of the one-sided shift map, which implies positive entropy of the system and hence chaotic behavior. The essential tool is the horseshoe hypotheses proposed by Kennedy and Yorke, which will be reviewed prior to the discussion of the main finding. Moreover, the existence of chaos is also illustrated in the light of homoclinic intersections of stable and unstable manifolds

35

Non-Smooth Bifurcation and Chaos in a DC-DC Buck Converter

A direct-current-direct-current (DC-DC) buck converter with integrated load current feedback is studied with three kinds of Poincaré maps. The external corner-collision bifurcation occurs when the crossing number per period varies, and the internal corner-collision bifurcations occur along with period-doubling and period-tripling bifurcations in this model. The multi-band chaos roots in external corner-collision bifurcation and often grows into 1-band chaos. A new kind of chaotic sliding orbits, which is more complex for non-smooth systems, is also found in this model.

Qin, Zhi-Ying; Lu, Qi-Shao

2007-04-01

36

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

Directory of Open Access Journals (Sweden)

Full Text Available 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

2010-06-01

37

Design of Controllers for Single-Input Dual-Output Synchronous DC-DC Buck Converter

Directory of Open Access Journals (Sweden)

Full Text Available Design and control techniques for a Single Input Dual Output (SIDO Synchronous DC-DC Buck Converter are presented. The advantage of this converter eliminates one MOSFET switch and its drive circuitry when compared to the conventional converter and in this system both output voltages are generated by the same integrated power converter. A Genetic Algorithm assisted PI controller is designed to maintain the output voltages to a constant value against load and line variations and compared with existing PI controller. The parameters of the controller are designed using various techniques like SISOTOOL (GUI, Internal Model Control and Binary Genetic Algorithm. The Discrete PI controller is also developed for the above converter. All the controllers are simulated using MATLAB and their performances are compared in terms of Peak overshoot, Rise time and Settling time. The system is also developed using real components and the results are obtained in open loop mode.

S.Augustilindiya

2013-08-01

38

A low noise high efficiency buck DC-DC converter with sigma-delta modulation

International Nuclear Information System (INIS)

Some research efforts to improve the efficiency and noise performance of buck DC-DC converters are explored. A carefully designed power MOSFET driver, including a dead time controller, discontinuous current mode (DCM) controller and gate width controller, is proposed to improve efficiency. Instead of PWM modulation, sigma-delta modulation is introduced into the feedback loop of the converter to move out the clock-referred harmonic spike. The proposed converter has been designed and fabricated by a 0.35 ?m CMOS process. Measured results show that the peak efficiency of the converter can reach 93% and sigma-delta modulation suppresses the harmonic spike by 30 dB over PWM modulation. (semiconductor integrated circuits)

39

A low noise high efficiency buck DC-DC converter with sigma-delta modulation

Energy Technology Data Exchange (ETDEWEB)

Some research efforts to improve the efficiency and noise performance of buck DC-DC converters are explored. A carefully designed power MOSFET driver, including a dead time controller, discontinuous current mode (DCM) controller and gate width controller, is proposed to improve efficiency. Instead of PWM modulation, sigma-delta modulation is introduced into the feedback loop of the converter to move out the clock-referred harmonic spike. The proposed converter has been designed and fabricated by a 0.35 {mu}m CMOS process. Measured results show that the peak efficiency of the converter can reach 93% and sigma-delta modulation suppresses the harmonic spike by 30 dB over PWM modulation. (semiconductor integrated circuits)

Cai Shujiang; Pi Changming; Yan Wei; Li Wenhong, E-mail: wenhongli@fudan.edu.cn [State Key Laboratory of ASIC and Systems, Fudan University, Shanghai 201203 (China)

2011-07-15

40

A low noise high efficiency buck DC-DC converter with sigma—delta modulation

Some research efforts to improve the efficiency and noise performance of buck DC—DC converters are explored. A carefully designed power MOSFET driver, including a dead time controller, discontinuous current mode (DCM) controller and gate width controller, is proposed to improve efficiency. Instead of PWM modulation, sigma-delta modulation is introduced into the feedback loop of the converter to move out the clock-referred harmonic spike. The proposed converter has been designed and fabricated by a 0.35 ?m CMOS process. Measured results show that the peak efficiency of the converter can reach 93% and sigma-delta modulation suppresses the harmonic spike by 30 dB over PWM modulation.

Shujiang, Cai; Changming, Pi; Wei, Yan; Wenhong, Li

2011-07-01

41

HIGH PERFORMANCE ALGORITHMS FOR THE CONTROL OF BUCK DC-DC CONVERTERS

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, two control methods are presented for controlling the DC-DC converters. These proposed control algorithms are tailored to buck DC-DC converter, so as to optimize the performance of the converter. First, a model predictive control (MPC method which uses a short prediction horizon is proposed. Since a short prediction horizon is used, the optimization solution can be derived analytically so that the algorithm becomes simple enough and can be implemented on-line. Further, the reference tracking error of inductance current is chosen as the penalized output. Second, a three-level hysteresis control method is proposed. This is naturally the extension of the conventional hysteresis control. The basic principle is to set the duty ratio in the central layer band as the steady-state duty ratio. Lastly, the load identification based on an adaptation of fuzzy control is proposed. Computer simulations have been carried out to investigate the effectiveness of the proposedalgorithms. Comparison with the well-known PID-PWM method is also presented. The advantage of this approach lies in its good trade-off between simple implementation, rise-time and overshoot in the output voltage response.

ABU ZAHARIN AHMAD,

2010-10-01

42

Design of high efficiency dual-mode buck DC-DC converter

International Nuclear Information System (INIS)

A buck DC-DC switching regulator with high efficiency is implemented by automatically altering the modulation mode according to load current, and it can operate with an input range of 4.5 to 30 V. At light load current, the converter operates in skip mode. The converter enters PWM mode operation with increasing load current. It reduces the switching loss at light load and standby state, which results in prolonging battery lifetime and stand-by time. Meanwhile, externally adjustable soft-start minimizes the inrush supply current and avoids the overshoot of output voltage at initial startup. The regulator is fabricated by a 0.6 ?m CDMOS process. The test results show that, under the condition of 3.3 V output, the efficiency is up to 64% at 5 mA and the maximum efficiency is 95.5%.

43

Low-temperature operation of a Buck DC/DC converter

Low-temperature (77 K) operation of a 42/28 V, 175 W, 50 kHz PWM Buck DC/DC converter designed with commercially available components is reported. Overall, the converter losses decreased at 77 K compared to room temperature operation. A full-load efficiency of 97 percent was recorded at liquid-nitrogen temperature, compared to 95.8 percent at room temperature. Power MOSFET operation improved significantly where as the output rectifier operation deteriorated at low-temperature. The performance of the output filter inductor and capacitor did not change significantly at 77 K compared to room temperature performance. It is possible to achieve high-density and high efficiency power conversion at low-temperatures due to improved electronic, electrical and thermal properties of materials.

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

1995-01-01

44

Design of high efficiency dual-mode buck DC-DC converter

Energy Technology Data Exchange (ETDEWEB)

A buck DC-DC switching regulator with high efficiency is implemented by automatically altering the modulation mode according to load current, and it can operate with an input range of 4.5 to 30 V. At light load current, the converter operates in skip mode. The converter enters PWM mode operation with increasing load current. It reduces the switching loss at light load and standby state, which results in prolonging battery lifetime and stand-by time. Meanwhile, externally adjustable soft-start minimizes the inrush supply current and avoids the overshoot of output voltage at initial startup. The regulator is fabricated by a 0.6 {mu}m CDMOS process. The test results show that, under the condition of 3.3 V output, the efficiency is up to 64% at 5 mA and the maximum efficiency is 95.5%.

Lai Xinquan; Zeng Huali; Ye Qiang; He Huisen; Zhang Shasha; Sun Yuqing, E-mail: zenghuali4213@126.com, E-mail: xqlai@mail.xidian.edu.cn [Institute of Electronic CAD, Xidian University, Xi' an 710071 (China)

2010-11-15

45

Design of high efficiency dual-mode buck DC-DC converter

A buck DC—DC switching regulator with high efficiency is implemented by automatically altering the modulation mode according to load current, and it can operate with an input range of 4.5 to 30 V. At light load current, the converter operates in skip mode. The converter enters PWM mode operation with increasing load current. It reduces the switching loss at light load and standby state, which results in prolonging battery lifetime and stand-by time. Meanwhile, externally adjustable soft-start minimizes the inrush supply current and avoids the overshoot of output voltage at initial startup. The regulator is fabricated by a 0.6 ?m CDMOS process. The test results show that, under the condition of 3.3 V output, the efficiency is up to 64% at 5 mA and the maximum efficiency is 95.5%.

Xinquan, Lai; Huali, Zeng; Qiang, Ye; Huisen, He; Shasha, Zhang; Yuqing, Sun

2010-11-01

46

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

47

Design of a DC/DC buck converter for ultra-low power applications in 65nm CMOS Process

Digital Repository Infrastructure Vision for European Research (DRIVER)

Switching mode DC/DC converters are critical building blocks in portable devices and hence their power efficiency, accuracy and cost are a major issue. The primary focus of this thesis is to address these critical issues.This thesis focuses on the different methods of feedback control loop which are employed in the switching mode DC/DC converters such as voltage mode control and current mode control. It also discusses about the structure of buck converter and tries to find an efficient soluti...

Safari, Naeim

2012-01-01

48

An optimal current observer for predictive current controlled buck DC-DC converters.

In digital current mode controlled DC-DC converters, conventional current sensors might not provide isolation at a minimized price, power loss and size. Therefore, a current observer which can be realized based on the digital circuit itself, is a possible substitute. However, the observed current may diverge due to the parasitic resistors and the forward conduction voltage of the diode. Moreover, the divergence of the observed current will cause steady state errors in the output voltage. In this paper, an optimal current observer is proposed. It achieves the highest observation accuracy by compensating for all the known parasitic parameters. By employing the optimal current observer-based predictive current controller, a buck converter is implemented. The converter has a convergently and accurately observed inductor current, and shows preferable transient response than the conventional voltage mode controlled converter. Besides, costs, power loss and size are minimized since the strategy requires no additional hardware for current sensing. The effectiveness of the proposed optimal current observer is demonstrated experimentally. PMID:24854061

Min, Run; Chen, Chen; Zhang, Xiaodong; Zou, Xuecheng; Tong, Qiaoling; Zhang, Qiao

2014-01-01

49

An Optimal Current Observer for Predictive Current Controlled Buck DC-DC Converters

Directory of Open Access Journals (Sweden)

Full Text Available In digital current mode controlled DC-DC converters, conventional current sensors might not provide isolation at a minimized price, power loss and size. Therefore, a current observer which can be realized based on the digital circuit itself, is a possible substitute. However, the observed current may diverge due to the parasitic resistors and the forward conduction voltage of the diode. Moreover, the divergence of the observed current will cause steady state errors in the output voltage. In this paper, an optimal current observer is proposed. It achieves the highest observation accuracy by compensating for all the known parasitic parameters. By employing the optimal current observer-based predictive current controller, a buck converter is implemented. The converter has a convergently and accurately observed inductor current, and shows preferable transient response than the conventional voltage mode controlled converter. Besides, costs, power loss and size are minimized since the strategy requires no additional hardware for current sensing. The effectiveness of the proposed optimal current observer is demonstrated experimentally.

Run Min

2014-05-01

50

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

51

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents comparative performance between Analog and digital controller on DC/DC buck-boost converter four switch. The design of power electronic converter circuit with the use of closed loop scheme needs modeling and then simulating the converter using the modeled equations. This can easily be done with the help of state equations and MATLAB/SIMULINK as a tool for simulation of those state equations. DC/DC Buckboost converter in this study is operated in buck (ste...

Abdessamad, Benlafkih; Salah-ddine, Krit; Mohamed, Chafik Elidrissi

2013-01-01

52

Adaptive terminal sliding-mode control strategy for DC-DC buck converters.

This paper presents an adaptive terminal sliding mode control (ATSMC) strategy for DC-DC buck converters. The idea behind this strategy is to use the terminal sliding mode control (TSMC) approach to assure finite time convergence of the output voltage error to the equilibrium point and integrate an adaptive law to the TSMC strategy so as to achieve a dynamic sliding line during the load variations. In addition, the influence of the controller parameters on the performance of closed-loop system is investigated. It is observed that the start up response of the output voltage becomes faster with increasing value of the fractional power used in the sliding function. On the other hand, the transient response of the output voltage, caused by the step change in the load, becomes faster with decreasing the value of the fractional power. Therefore, the value of fractional power is to be chosen to make a compromise between start up and transient responses of the converter. Performance of the proposed ATSMC strategy has been tested through computer simulations and experiments. The simulation results of the proposed ATSMC strategy are compared with the conventional SMC and TSMC strategies. It is shown that the ATSMC exhibits a considerable improvement in terms of a faster output voltage response during load changes. PMID:22877744

Komurcugil, Hasan

2012-11-01

53

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

54

Analysis of DC-DC Buck converter with chaotic dynamics using Wigner Distribution

Digital Repository Infrastructure Vision for European Research (DRIVER)

DC/DC converters exhibit subharmonicsand chaos when the switching action is governed byfeedback control. Since the use of converters isincreasing in Industries for various applications,deeper analysis of the appearance and the nature ofbifurcation is essential to stabilize its output onto adesired periodic solution. Time frequencyrepresentation is helpful in studying the fine structuresof frequency patterns such as sub harmonics and ultraharmonics of chaotic dynamics. This paper analyzesthe c...

Logamani, Premalatha

2010-01-01

55

A fast novel soft-start circuit for peak current-mode DC—DC buck converters

International Nuclear Information System (INIS)

A fully integrated soft-start circuit for DC—DC buck converters is presented. The proposed high speed soft-start circuit is made of two sections: an overshoot suppression circuit and an inrush current suppression circuit. The overshoot suppression circuit is presented to control the input of the error amplifier to make output voltage limit increase in steps without using an external capacitor. A variable clock signal is adopted in the inrush current suppression circuit to increase the duty cycle of the system and suppress the inrush current. The DC—DC converter with the proposed soft-start circuit has been fabricated with a standard 0.13 ?m CMOS process. Experimental results show that the proposed high speed soft-start circuit has achieved less than 50 ?s start-up time. The inductor current and the output voltage increase smoothly over the whole load range. (semiconductor integrated circuits)

56

Mission Profile Based Optimization of a Synchronous-Buck DC-DC Converter for a Wearable Power System

Digital Repository Infrastructure Vision for European Research (DRIVER)

A Wearable Power System (WPS) is a portable fuel-to-electrical energy converter that is carried on the body and is able to supply an average of 20 W for 4 days and has a total weight of less than 4 kg. Due to limited total weight of the system, each system part must have the highest efficiency to weight ratio. This paper presents the optimization of a synchronous buck DC-DC converter that is used to regulate the variable power source to a constant 14 VDC for the load. Higher switching frequen...

Vasic, Miroslav; Round, S. D.; Biela, J.; Kolar, J. W.

2009-01-01

57

Digital Repository Infrastructure Vision for European Research (DRIVER)

This report is the result of a Master Thesis work done at Seaward Electronics Inc. in Beijing, China from June to December in 2007. The main goal for this thesis is to verify and improve the performance of Honey-PWM DC-DC converter, which has been fabricated by a standard 0.6um CMOS processes. The project was started with studying of Buck converter structure. After the understanding of the converter structure, the project goes in to the analyses phase for each sub-cells, including the theory,...

Chen, Juan

2008-01-01

58

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 model for a PEM fuel cell that can be used to design fuel cell simulator. The model is consisted of a DC-DC buck converter driven by PIC 16F877 microcontroller. The model can be used in design and analysis of fuel cell power systems by simulation or by using practically realized simulator.

Arsov, Goce L.; Georgi Georgievski

2009-01-01

59

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 model for a PEM fuel cell that can be used to design fuel cell simulator. The model is consisted of a DC-DC buck converter driven by PIC 16F877 microcontroller. The model can be used in design and analysis of fuel cell power systems by simulation or by using practically realized simulator.

Goce L. Arsov

2009-06-01

60

Directory of Open Access Journals (Sweden)

Full Text Available this paper presents comparative performance between Analog and digital controller on DC/DC buck-boost converter four switch. The design of power electronic converter circuit with the use of closed loop scheme needs modeling and then simulating the converter using the modeled equations. This can easily be done with the help of state equations and MATLAB/SIMULINK as a tool for simulation of those state equations. DC/DC Buckboost converter in this study is operated in buck (step-down and boost (step-up modes.

Benlafkih Abdessamad

2013-01-01

61

Digital Repository Infrastructure Vision for European Research (DRIVER)

this paper presents comparative performance between Analog and digital controller on DC/DC buck-boost converter four switch. The design of power electronic converter circuit with the use of closed loop scheme needs modeling and then simulating the converter using the modeled equations. This can easily be done with the help of state equations and MATLAB/SIMULINK as a tool for simulation of those state equations. DC/DC Buckboost converter in this study is operated in buck (step-down) and boost ...

Benlafkih Abdessamad; Krit Salah-Ddine; Chafik Elidrissi Mohamed

2013-01-01

62

MCU Controlled DC-DC Buck/Boost Converter for Supercapacitors

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work is focused on DC to DC conversion, what is a crucial function to enable the use of supercapacitors for energy storage. A theoretical study and comparison of methods, algorithms and techniques for software controlled DC-DC converters have been used to develop a system what can step up or down a DC variable voltage and transform it into a steady state voltage. As a result a new control theory based on Bang-Bang control has been developed with an ARM LPC1768 processor. It was implement...

Querol Borra?s, Jorge

2012-01-01

63

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)

64

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.

Changming, Pi; Wei, Yan; Ke, Zhang; Wenhong, Li

2010-08-01

65

Energy Technology Data Exchange (ETDEWEB)

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 {mu}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)

Pi Changming; Yan Wei; Zhang Ke; Li Wenhong, E-mail: wenhongli@fudan.edu.c [State Key Laboratory of ASIC and Systems, Fudan University, Shanghai 201203 (China)

2010-08-15

66

A novel buck/LDO dual-mode DC—DC converter for efficiency improvement

A novel buck/LDO dual-mode (BLDM) converter using a multiplexing power MOS transistor is proposed, which adaptively switches between buck mode and LDO mode to improve conversion efficiency. The chip was fabricated in a standard 0.35 ?m CMOS process. Measurement results show that the peak efficiency is 97%. For the light load operation, the efficiency is improved by 14%. The efficiency keeps higher than 82.5% for the load current of 50 mA without any complex control or extra EMI due to the normal method of pulse frequency modulation (PFM) control used for improving the light load efficiency. It does not cost much extra chip area because no additional regulator PMOS is needed. It is more suitable for noise-restricted systems and battery-powered electronic devices for when battery voltage drops because of long hours of work.

Shiquan, Fan; Zhongming, Xue; Hao, Lu; Hui, Zhao; Li, Geng

2013-10-01

67

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

68

Loss model for a high frequency and low load DC/DC synchronous buck converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work presents a behavioral-analytical hybrid loss model for a buck converter. The model has been designed for a wide operating frequency range up to 4MHz and a low power range (below 20W). It is focused on the switching losses obtained in the power MOSFETs. Main advantages of the model are the fast calculation time and a good accuracy. It has been validated by simulation and experimentally with one Ga, power transistor and two Si MOSFETs. Results show good agreement between measurements ...

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

2012-01-01

69

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: English Abstract in spanish 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

70

BI-DIRECTIONAL DC/DC CONVERTER

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work presents bidirectional DC/DC converter, which is used for a bidirectional energy flow in the hybrid or electric vehicles. The converter has two main operating modes - step-down mode (Buck) and step-up mode (Boost). When operating in Buck mode, the converter uses an excess energy from breaking or driving downhill to charge an energy storage device. In contrary, when the converter works in Boost mode, the accumulated energy is transferred from energy device to the electric motor. Befo...

Fis?er, Primoz?

2011-01-01

71

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

72

Energy Technology Data Exchange (ETDEWEB)

Photovoltaic (PV) cells for powering direct current (DC) motors are designed to provide maximum output power at the rated conditions of the motors. This paper presented the dynamic and steady-state characteristics of DC shunt, series and permanent-magnet motors fed by PV cells via a DC-DC buck-boost (step up-step down) switch mode converter. It considered the nonlinearities of the output characteristics of the PV cells and that of the magnetization curve of the machines. In order to address the problem of voltage regulation of the PV cells and the variation in solar illumination, the duty cycle controls the output voltage of the DC-DC converter to maintain a fixed voltage across the terminals of the motors at any realistic loading conditions. In this study, the DC-DC buck-boost switch mode converter achieved a fixed voltage across the terminals of the motors and therefore good speed regulation under a wide range of loading conditions and solar intensities. The entire study was carried out using the Matrix Laboratory Program MATLAB{sup TM} software.

Widyan, M.S.

2010-07-01

73

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 improves the full-bridge converter by introducing a reset winding in series with the resonant inductance to make the clamping diode current decay rapidly when it conducts. The reset winding not only reduces the conduction losses, but also makes the clamping diodes naturally turn-off and avoids the reverse recovery. As the diodes are turned off naturally and reverse recovery voltage is avoided the distortions caused in the output voltage is removed to a maximum extend by varying the turns ratio of the transformer. The energy stored in the reset winding is also increased by which the inductor value of the snubber circuit to turn off the clamping diodes also increases, which results in reductions in the distortions of the output voltage.

Pravin Subhash Pawar *

2014-07-01

74

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish 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

75

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish 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.

76

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

Chunhong, Zhang; Haigang, Yang; Shi, Richard

2013-06-01

77

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)

78

By using a quadratic compensation slope, a CMOS current-mode buck DC-DC converter with constant frequency characteristics over wide input and output voltage ranges has been developed. The use of a quadratic slope instead of a conventional linear slope makes both the damping factor in the transfer function and the frequency bandwidth of the current feedback loop independent of the converter's output voltage settings. When the coefficient of the quadratic slope is chosen to be dependent on the input voltage settings, the damping factor in the transfer function and the frequency bandwidth of the current feedback loop both become independent of the input voltage settings. Thus, both the input and output voltage dependences in the current feedback loop are eliminated, the frequency characteristics become constant, and the frequency bandwidth is maximized. To verify the effectiveness of a quadratic compensation slope with a coefficient that is dependent on the input voltage in a buck DC-DC converter, we fabricated a test chip using a 0.18µm high-voltage CMOS process. The evaluation results show that the frequency characteristics of both the total feedback loop and the current feedback loop are constant even when the input and output voltages are changed from 2.5V to 7V and from 0.5V to 5.6V, respectively, using a 3MHz clock.

Sai, Toru; Sugimoto, Yasuhiro

79

International Nuclear Information System (INIS)

Buck converters are widely used in switch mode power supplies due to their high efficiency, fast switching actions, low volume and weight, and low cost. These converters are variable structure systems and contain nonlinearities which lead to oscillations during operation. Various Control techniques have been investigated and analyzed in order to minimize oscillations during the operation of the converter, in particular, under non-linear situations. In this paper, an attempt is being made to control the oscillation of the buck converter by using sliding mode controller. The SMC (Sliding Mode Controller) is a nonlinear controller which can handle nonlinearities, provides good dynamic response and simple implementation. The proposed control scheme is implemented and simulated in MATLAB/Simulink. The results of SMC are compared with cascade controller and are presented in this paper. (author)

80

An Efficient DC- DC Converter with Bidirectional Power Flow

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

81

Hybrid behavioral-analytical loss model for a high frequency and low load DC/DC buck converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work presents a behavioral-analytical hybrid loss model for a buck converter. The model has been designed for a wide operating frequency range up to 4MHz and a low power range (below 20W). It is focused on the switching losses obtained in the power MOSFETs. Main advantages of the model are the fast calculation time (below 8.5 seconds) and a good accuracy, which makes this model suitable for the optimization process of the losses in the design of a converter. It has been validated by simu...

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

2012-01-01

82

Extra-High-Voltage DC-DC Boost Converters Topology with Simple Control Strategy

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the topology of operating DC-DC buck converter in boost mode for extra-high-voltage applications. Traditional DC-DC boost converters are used in high-voltage applications, but they are not economical due to the limited output voltage, efficiency and they require two sensors with complex control algorithm. Moreover, due to the effect of parasitic elements the output voltage and power transfer efficiency of DC-DC converters are limited. These limitations are overcome by usin...

Rajambal, K.; Sanjeevikumar, P.

2009-01-01

83

Hybrid battery with bi-directional DC/DC converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

84

SIMPLIFIED APPROACHES FOR CONTROLLING DC-DC POWER CONVERTERS

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

85

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

86

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

87

High-Efficiency dc/dc Converter

High-efficiency dc/dc converter has been developed that provides commonly used voltages of plus or minus 12 Volts from an unregulated dc source of from 14 to 40 Volts. Unique features of converter are its high efficiency at low power level and ability to provide output either larger or smaller than input voltage.

Sturman, J.

1982-01-01

88

An Integrated High Efficiency DC-DC Converter in 65 nm CMOS

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis work describes the implementation perspective of an integrated high efficiency DC-DC converter implemented in 65 nm CMOS. The implemented system employs the Buck converter topology to down-convert the input battery voltages. This converter offers its use as a power management unit in portable battery operated devices. This thesis work includes the description of a basic Buck converter along with the various key equations involved which describe the Buck operation as well as are us...

Manh, Vir Varinder

2010-01-01

89

General-purpose fuzzy controller for dc-dc converters

Energy Technology Data Exchange (ETDEWEB)

In this paper, a general-purpose fuzzy controller for dc-dc converters is investigated. Based on a qualitative description of the system to be controlled, fuzzy controllers are capable of good performances, even for those systems where linear control techniques fail, e.g., when a mathematical description is not available or is in the presence of wide parameter variations. The presented approach is general and can be applied to any dc-dc converter topologies. Controller implementation is relatively simple and can guarantee a small-signal response as fast and stable as other standard regulators and an improved large-signal response. Simulation results of Buck-Boost and Sepic converters show control potentialities.

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

1997-01-01

90

Recognition of dynamic patterns in dc-dc switching converters

Techniques are presented for analyzing the dynamic patterns of power flow in high-frequency dc-dc switching converters. Emphasis is placed on exploring methods for developing reduced-order models of power electronic circuits for simulation and state-space averaging. Tools from selective modal analysis are used to develop the dynamic pattern recognition algorithm that facilitates the classification of circuit modules. The algorithm is intended for the analysis of converters derived from the canonical switching call, i.e., the buck, boost, and flyback converters.

Leeb, Steven B.; Kirtley, James L.; Verghese, George C.

91

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

92

Design of Low Voltage Low Power and Highly Efficient DC-DC Converters, Theoretical Guidelines

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

93

Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

Lee, F. C.; Mahmoud, M. F.; Yu, Y.

1980-01-01

94

Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

Lee, F. C.; Mahmoud, M. F.; Yu, Y.

1980-04-01

95

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

96

Improved Models for DC-DC Converters

Digital Repository Infrastructure Vision for European Research (DRIVER)

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. ...

Johansson, Bengt

2003-01-01

97

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

98

Parallel Linear–Assisted DC-DC Switching Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

Linear-assisted DC-DC converters or linear-switching hybrid DC–DC converters are power supply structures in which some important advantages from linear regulators and DC-DC switching converters converge. Normally, in linear assisted converters a series linear regulator is used in order to provide a constant ripple-free output voltage. However, this article shows the proposal of a linear–assisted DCDC converter or linear–&–switching hybrid converter including a parallel linear re...

Marti?nez Garci?a, Herminio; Grau Saldes, Antoni; Bolea Monte, Yolanda; Ga?miz Caro, Juan

2011-01-01

99

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

100

Efficient, lightweight dc/dc switching converter

Converters have input properties of boost power stage and output properties of buck power stage, yet they perform general conversion function with high efficiency. Other features include non-pulsating input/output currents, use of capacitive energy transfer, low output voltage ripple, reduced EMI, and small size.

Cuk, S.; Middlebrook, R. D.

1981-01-01

101

In this paper, a high accuracy, high efficiency, and wide current-sensing range current-mode PWM buck converter with on-chip current-sensing technique is presented. The proposed current-sensing circuit uses simple switch technique to achieve high accuracy, high power efficiency, and high line regulation. The test chip is fabricated using TSMC 0.18µm 1P6M 3.3V CMOS process. The measurement results show that the buck converter with on-chip current-sensing circuit can operate from 700kHz to 3MHz with a supply voltage of 1.5-5V and the output voltage of 0.5-4.5V for lithium ion battery applications. The accuracy of the proposed current-sensing circuit is exceeds 89.8% for load current from 50mA to 500mA and for temperature from 0°C to 100°C. The peak power efficiency of the buck converter is up to 95.5%.

Cheng, Kuo-Hsing; Su, Chia-Wei; Ko, Hsin-Hsin

102

Modeling of chaotic dc-dc converters by iterated nonlinear mappings

In parameter ranges where conventional methods break down, dc-dc converters may be described by iterated mappings, a nonlinear discrete modeling technique. The underlying principles are explained and are applied to the example of a PWM-controlled buck converter. Stable behavior and bifurcations to chaos are predicted by numerical evaluation of the governing mapping and are confirmed by experiment.

Hamill, David C.; Deane, Jonathan H. B.; Jefferies, David J.

1992-01-01

103

HYBRID MODELING OF OPEN LOOP DC-DC CONVERTERS

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Power electronic converters always have been circuits of difficult modelling because differential equations that describe them have discontinuities. Although this situation has been improved since the appearance of the Hybrid Systems theory, able to jointly describe both continuous and discrete beha [...] viors exhibited by some physical systems, nowadays it is possible to obtain very precise models which help us in the study and design of such circuits. An excellent option for the discrete part model (reactive system) is to use statecharts, since this powerful language has recently been implemented and named Stateflow as a part of the Simulink toolbox of Matlab. So, today, the complete modeling of some hybrid systems within Matlab environment is possible. In this work the open loop hybrid modeling and simulation of the well-known dc-dc converters named buck and boost, using Matlab-Simulink-Stateflow, is presented

Ekaitz, Zulueta; Teodoro, Rico; José María, González de Durana.

2003-12-01

104

SIMPLIFIED APPROACHES FOR CONTROLLING DC-DC POWER CONVERTERS

Directory of Open Access Journals (Sweden)

Full Text Available 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 transfer function (TF. The comparative study Resultsemphasize that FLC tuned by PI controller is superior to the other control strategies because of fast transient response, minimum steady state error and good disturbance rejection under various variations of the operating conditions. Hence, it achieves the most tightly output voltage regulation.

M. M. ABDEL AZIZ

2012-02-01

105

HYBRID MODELING OF OPEN LOOP DC-DC CONVERTERS

Directory of Open Access Journals (Sweden)

Full Text Available Power electronic converters always have been circuits of difficult modelling because differential equations that describe them have discontinuities. Although this situation has been improved since the appearance of the Hybrid Systems theory, able to jointly describe both continuous and discrete behaviors exhibited by some physical systems, nowadays it is possible to obtain very precise models which help us in the study and design of such circuits. An excellent option for the discrete part model (reactive system is to use statecharts, since this powerful language has recently been implemented and named Stateflow as a part of the Simulink toolbox of Matlab. So, today, the complete modeling of some hybrid systems within Matlab environment is possible. In this work the open loop hybrid modeling and simulation of the well-known dc-dc converters named buck and boost, using Matlab-Simulink-Stateflow, is presented

Ekaitz Zulueta

2003-12-01

106

HYBRID MODELING OF OPEN LOOP DC-DC CONVERTERS

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Power electronic converters always have been circuits of difficult modelling because differential equations that describe them have discontinuities. Although this situation has been improved since the appearance of the Hybrid Systems theory, able to jointly describe both continuous and discrete beha [...] viors exhibited by some physical systems, nowadays it is possible to obtain very precise models which help us in the study and design of such circuits. An excellent option for the discrete part model (reactive system) is to use statecharts, since this powerful language has recently been implemented and named Stateflow as a part of the Simulink toolbox of Matlab. So, today, the complete modeling of some hybrid systems within Matlab environment is possible. In this work the open loop hybrid modeling and simulation of the well-known dc-dc converters named buck and boost, using Matlab-Simulink-Stateflow, is presented

Ekaitz, Zulueta; Teodoro, Rico; José María, González de Durana.

107

Intelligent dc-dc Converter Technology Developed and Tested

The NASA Glenn Research Center and the Cleveland State University have developed a digitally controlled dc-dc converter to research the benefits of flexible, digital control on power electronics and systems. Initial research and testing has shown that conventional dc-dc converters can benefit from improved performance by using digital-signal processors and nonlinear control algorithms.

Button, Robert M.

2001-01-01

108

Fractional DC/DC Converter in Solar-Powered Electrical Generation Systems

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper deals with the fractional modeling of a DC-DC buck-boost converter, suitable in solar-powered electrical generation systems, and the design of a fractional controller for the aforementioned switching converter. Although the modeling and design of the controller is carried out for this particular DC-DC converter,it can be easily extended to other kind of switching converter. In addition, the comparison between integer-order plant/controller and fractional-order plants/controll...

Marti?nez Gonza?lez, Rube?n; Bolea Monte, Yolanda; Grau Saldes, Antoni; Marti?nez Garci?a, Herminio

2009-01-01

109

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

110

Regulation of a lightweight high efficiency capacitator diode voltage multiplier dc-dc converter

A method for the regulation of a capacitor diode voltage multiplier dc-dc converter has been developed which has only minor penalties in weight and efficiency. An auxiliary inductor is used, which only handles a fraction of the total power, to control the output voltage through a pulse width modulation method in a buck boost circuit.

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

1976-01-01

111

Regulation of a lightweight high efficiency capacitor diode voltage multiplier dc-dc converter

A method for the regulation of a capacitor diode voltage multiplier dc-dc converter has been developed which has only minor penalties in weight and efficiency. An auxiliary inductor is used, which only handles a fraction of the total power, to control the output voltage through a pulse width modulation method in a buck boost circuit.

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

1976-01-01

112

Sliding Mode Control of Dc-Dc Boost Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

113

Extra-High-Voltage DC-DC Boost Converters Topology with Simple Control Strategy

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the topology of operating DC-DC buck converter in boost mode for extra-high-voltage applications. Traditional DC-DC boost converters are used in high-voltage applications, but they are not economical due to the limited output voltage, efficiency and they require two sensors with complex control algorithm. Moreover, due to the effect of parasitic elements the output voltage and power transfer efficiency of DC-DC converters are limited. These limitations are overcome by using the voltage lift technique, opens a good way to improve the performance characteristics of DC-DC converter. The technique is applied to DC-DC converter and a simplified control algorithm in this paper. The performance of the controller is studied for both line and load disturbances. These converters perform positive DC-DC voltage increasing conversion with high power density, high efficiency, low cost in simple structure, small ripples, and wide range of control. Simulation results along theoretical analysis are provided to verify its performance.

K. Rajambal

2009-01-01

114

Custom DC-DC converters for distributing power in SLHC trackers

A power distribution scheme based on the use of on-board DC-DC converters is proposed to efficiently distribute power to the on-detector electronics of SLHC trackers. A comparative analysis of different promising converter topologies is presented, leading to the choice of a magneticbased buck converter as a first conversion stage followed by an on-chip switched capacitors converter. An overall efficiency above 80% is estimated for the practical implementation proposed.

Allongue, B; Blanchot, G; Faccio, F; Fuentes, C; Mattavelli, P; Michelis, S; Orlandis, S; Spiazzi, G

2008-01-01

115

Step-Up DC/DC Converters with the Tristate Quasi-Z-Source Network

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the Step-Up DC/DC Converters With The Tristate quasi- Z-Source Network. This paper is based on the step-up dc/dc converter family with a cascaded quasi-Z-source network. The tri-stage network could be derived by adding of one diode, one inductor, and two capacitors to the two quasi-Z-source inverter. It has advantages of Voltage boost and buck functions in a single stage, continuous input current and improved reliability. Theoretical analysis of the tri-stage quasi Z-...

Diwahar, S.; Surjith Barnala, S.; Vikneswaran, N.; Gurunathan, M.

2013-01-01

116

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)

117

Sliding mode controllers for the regulation of DC-DC power converters

Digital Repository Infrastructure Vision for European Research (DRIVER)

Sliding mode controllers are derived for the control of the average output voltage in DC/DC power converters. The controller design is carried out on the basis of well-known bilinear models of such circuits. A cascaded control structure is chosen for ease of control realization and to exploit the motion separation property of this power converter. The performance of the proposed sliding mode controllers is tested for the buck and boost converter type. The numerical simulations will demonstrat...

Arau?jo, R.; Leite, V.; Freitas, D.

2003-01-01

118

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

119

Analysis of the coupling behavior of PEM fuel cells and DC-DC converters

Energy Technology Data Exchange (ETDEWEB)

The connection between PEM fuel cells and common DC-DC converters is examined. The analysis is model-based and done for boost, buck and buck-boost converters. In a first step, the effect of the converter ripples upon the PEM fuel cell is shown. They introduce oscillations in the fuel cell. Their appearance is explained, discussed and possibilities for their suppression are given. After that, the overall behaviors of the coupled fuel cell-converter systems are analyzed. It is shown, that neither stationary multiplicities nor oscillations can be introduced by the couplings and therefore separate control approaches for both the PEMFC and the DC-DC converters are applicable. (author)

Groetsch, M.; Mangold, M.; Kienle, A. [Max Planck Institute for Dynamics of Complex Technical Systems, Process Synthesis and Process Dynamics Group, Sandtorstrasse 1, 39106 Magdeburg (Germany); Kienle, A. [Otto-von-Guericke-Universitaet Magdeburg, Lehrstuhl fuer Automatisierungstechnik / Modellbildung, Universitaetsplatz 2, 39106 Magdeburg (Germany)

2009-07-01

120

Analysis of the Coupling Behavior of PEM Fuel Cells and DC-DC Converters

Directory of Open Access Journals (Sweden)

Full Text Available The connection between PEM fuel cells and common DC-DC converters is examined. The analysis is model-based and done for boost, buck and buck-boost converters. In a first step, the effect of the converter ripples upon the PEM fuel cell is shown. They introduce oscillations in the fuel cell. Their appearance is explained, discussed and possibilities for their suppression are given. After that, the overall behaviors of the coupled fuel cell-converter systems are analyzed. It is shown, that neither stationary multiplicities nor oscillations can be introduced by the couplings and therefore separate control approaches for both the PEMFC and the DC-DC converters are applicable.

Achim Kienle

2009-03-01

121

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

122

Analysis of the Coupling Behavior of PEM Fuel Cells and DC-DC Converters

Digital Repository Infrastructure Vision for European Research (DRIVER)

The connection between PEM fuel cells and common DC-DC converters is examined. The analysis is model-based and done for boost, buck and buck-boost converters. In a first step, the effect of the converter ripples upon the PEM fuel cell is shown. They introduce oscillations in the fuel cell. Their appearance is explained, discussed and possibilities for their suppression are given. After that, the overall behaviors of the coupled fuel cell-converter systems are analyzed. It is shown, that neith...

Achim Kienle; Markus Grötsch; Michael Mangold

2009-01-01

123

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

124

Simulation analysis of cascade controller for DC-DC bank converter

International Nuclear Information System (INIS)

Power electronic converters are periodic variable structure systems due to their switched operation. During the last few decades several new dc-dc converter topologies have emerged. Buck converter being simple in topology, has recently drawn attraction of many researchers. Basically, a buck converter is highly underdamped system. In order to overcome the developed oscillations in output of this converter, various control techniques have been proposed. However, these techniques are fraught with many drawbacks. This paper focus on a cascade controller based buck topology. Steady state analysis is given in this paper which shows output voltage and inductor current in detail. Dynamic analysis for line and load variation is also presented. The buck topology is implemented and simulated in MATLAB/Simulink. The simulated results are presented. (author)

125

High voltage conversion ratio, switched C & L cells, step-down DC-DC converter

DEFF Research Database (Denmark)

The paper presents a high voltage conversion ratio DC-DC step-down topology obtained from a classical buck converter associated with an input switched-capacitor cell and an output switched-inductor cell. Analytical descriptions, the voltage and current limits of the main components are synthesized in a comparative form, related to the classical buck structure, in order to emphasis the advantages of the proposed converter. Digital simulations and experimental results obtained with a built prototype are compared. From the first evaluation, the proposed converter is expected to be effectively used at input to output voltage ratios higher than 20.

Pelan, Ovidiu; Muntean, Nicolae

2013-01-01

126

Dynamic Evolution Control for Fuel Cell DC-DC Converter

Directory of Open Access Journals (Sweden)

Full Text Available Fuel cells are new alternative energy resource that has a great promise for distributed generation and electric vehicle application. However, fuel cells have a slow response due to their slow internal electromechanical and thermodynamic response. To optimize the fuel cell system performance, a fuel cell DC-DC converter with an appropriate controller which can regulate the power flow and automatically adjust the converter output voltage is needed. This paper proposes a new control technique for fuel cell DC-DC power converter. Design of the proposed control method for fuel cell DC-DC power converter is provided. A new approach for converter controllers synthesis based on dynamic evolution control theory is presented. In this paper, synthesis example of boost DC-DC converter is discussed. Performance of the proposed dynamic evolution control under step load variation condition is simulated under Matlab-Simulink environment. Simulation results show that the proposed techniques are capable for controlling fuel cell DC-DC converter.

Ahmad Saudi Samosir

2011-04-01

127

METHOD FOR GENERATING DC-DC CONVERTERS WITH REQUIRED CHARACTERISTICS

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes an algorithmic method for generating DCâ€“DC converters with predetermined characteristics. This method uses the Main Topological Matrix MTM. The definition and attributes of the MTM are stated. The common properties for single-switch DC-DC converters are described. The proposed method has unique advantages over other methods. This method is fully algorithmic. In addition, this method basses on the design by parts, that facilitates the design of power electronic circuits. Moreover, by some examples we will show how this method used for generating all sub-class (sub-family of DC-DC converters with predetermined characteristics (e.g. galvanic isolation.

Murad Ahmed Ali Taher

2012-01-01

128

Design of DC-DC Converter for Flash Memory IPs

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Li-yan Jin; Woo-Young Jung; Ji-Hye Jang; Min-Sung Kim; Myeong-Seok Kim; Heon Park; Pan-Bong Ha; Young-Hee Kim

2013-01-01

129

DC-DC converters act as a black box to study various bifurcations. In the present study, the influence of external periodic interference signal in the input of DC-DC voltage-mode controlled buck converter has been considered. It is found that the presence of sinusoidal or saw-tooth interference signal whose frequency is comparable with the switching frequency of the converter or its rational multiples manifests as remerging chaotic band attractors (or Feigenbaum trees) and intermittent chaos. However, the presence of sinusoidal interference signal having irrational frequency ratios with the switching frequency of the converter leads to quasi-periodic route to chaos. The study was carried out both theoretically and experimentally.

Deivasundari, P.; Geetha, R.; Uma, G.; Murali, K.

2013-07-01

130

Early Oscillation Detection Technique for Hybrid DC/DC Converters

Oscillation or instability is a situation that must be avoided for reliable hybrid DC/DC converters. A real-time electronics measurement technique was developed to detect catastrophic oscillations at early stages for hybrid DC/DC converters. It is capable of identifying low-level oscillation and determining the degree of the oscillation at a unique frequency for every individual model of the converters without disturbing their normal operations. This technique is specially developed for space-used hybrid DC/DC converters, but it is also suitable for most of commercial and military switching-mode power supplies. This is a weak-electronic-signal detection technique to detect hybrid DC/DC converter oscillation presented as a specific noise signal at power input pins. It is based on principles of feedback control loop oscillation and RF signal modulations, and is realized by using signal power spectral analysis. On the power spectrum, a channel power amplitude at characteristic frequency (CPcf) and a channel power amplitude at switching frequency (CPsw) are chosen as oscillation level indicators. If the converter is stable, the CPcf is a very small pulse and the CPsw is a larger, clear, single pulse. At early stage of oscillation, the CPcf increases to a certain level and the CPsw shows a small pair of sideband pulses around it. If the converter oscillates, the CPcf reaches to a higher level and the CPsw shows more high-level sideband pulses. A comprehensive stability index (CSI) is adopted as a quantitative measure to accurately assign a degree of stability to a specific DC/DC converter. The CSI is a ratio of normal and abnormal power spectral density, and can be calculated using specified and measured CPcf and CPsw data. The novel and unique feature of this technique is the use of power channel amplitudes at characteristic frequency and switching frequency to evaluate stability and identify oscillations at an early stage without interfering with a DC/DC converter s normal operation. This technique eliminates the probing problem of a gain/phase margin method by connecting the power input to a spectral analyzer. Therefore, it is able to evaluate stability for all kinds of hybrid DC/DC converters with or without remote sense pins, and is suitable for real-time and in-circuit testing. This frequency-domain technique is more sensitive to detect oscillation at early stage than the time-domain method using an oscilloscope.

Wang, Bright L.

2011-01-01

131

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

132

Ionizing radiation effects on typical DC/DC converters

International Nuclear Information System (INIS)

Ionizing radiation effects of typical DC/DC converters are studied in this paper. The relationships between output voltage and irradiation dose under test conditions of output load and input voltage are discussed. The results show that the output voltage decreased with increasing the output load, and the input voltage has less effect on the output voltage. (authors)

133

Sliding Mode Control of Dc-Dc Boost Converter

Directory of Open Access Journals (Sweden)

Full Text Available 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 design software tool Matlab/Simulink is used for the simulations. The simulation results are presented. The simulation results show a fast dynamic response of the output voltage and robustness to load and input voltage variations.

Hanifi Guldemir

2005-01-01

134

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)

135

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 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.

Zhou, Guo-Hua; Xu, Jian-Ping; Bao, Bo-Cheng; Jin, Yan-Yan

2010-06-01

136

Dynamic Evolution Control for Fuel Cell DC-DC Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

Fuel cells are new alternative energy resource that has a great promise for distributed generation and electric vehicle application. However, fuel cells have a slow response due to their slow internal electromechanical and thermodynamic response. To optimize the fuel cell system performance, a fuel cell DC-DC converter with an appropriate controller which can regulate the power flow and automatically adjust the converter output voltage is needed. This paper proposes a new control technique fo...

Ahmad Saudi Samosir; Tole Sutikno; Abdul Halim Mohd Yatim

2011-01-01

137

Diodes as pseudo active elements in high frequency dc/dc converters

An approach to realizing zero-voltage switching in the entire family of high-frequency dc-dc converters is proposed. Utilizing the parasitic associated with the diode stored charge, it is shown that the diode reverse current established for charge removal can be used advantageously to accomplish soft switching. The resulting converter topologies differ from their hard-switched counterparts only by the presence of a resonant capacitor. Device and component stresses are moderate compared to existing quasi-resonant and resonant techniques. Converter analysis is complex as a result of the dominant diode nonlinearities, and no closed-form expressions are possible. Converter transfer characteristics are obtained through simulation, and operating limits are analytically obtained. The concept is validated by experimental results on buck, buck-boost, and boost converters rated approximately 100 W and operating at frequencies around 1 MHz.

Divan, D. M.

138

Design and Implementation of a FLC for DC-DC Converter in a Microcontroller for PV System

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the design and implementation of a simple fuzzy logic controller (FLC) for a DC-DC buck converter based on the PIC18F4550 microcontroller to control the lead acid battery charging voltage in solar cells applications. For cost consideration, an inexpensive 8-bit microcontroller is selected to program and implement the FLC proportional-integral. The obtained simulation and experimental results show the viability of the controller with a variation on the load of the buck conv...

Abel García-B.; Trejo-m, Francisco R.; Felipe Coyotl-M.; Rubén-T.; Hugo Romero-T.,

2013-01-01

139

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 filter size and currentsource characteristics. The Simulink circuit model for closed loop system of full bridgeDC – DC converter VSWT is developed and the same is used for simulation studies.

M. Vijaya Kumar

2012-08-01

140

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.

141

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

142

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

143

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

144

Digital Control Technologies for Modular DC-DC Converters

Recent trends in aerospace Power Management and Distribution (PMAD) systems focus on using commercial off-the-shelf (COTS) components as standard building blocks. This move to more modular designs has been driven by a desire to reduce costs and development times, but is also due to the impressive power density and efficiency numbers achieved by today's commercial DC-DC converters. However, the PMAD designer quickly learns of the hidden "costs" of using COTS converters. The most significant cost is the required addition of external input filters to meet strict electromagnetic interference (MIAMI) requirements for space systems. In fact, the high power density numbers achieved by the commercial manufacturers are greatly due to the lack of necessary input filters included in the COTS module. The NASA Glenn Research Center is currently pursuing a digital control technology that addresses this problem with modular DC-DC converters. This paper presents the digital control technologies that have been developed to greatly reduce the input filter requirements for paralleled, modular DC-DC converters. Initial test result show that the input filter's inductor size was reduced by 75 percent, and the capacitor size was reduced by 94 percent while maintaining the same power quality specifications.

Button, Robert M.; Kascak, Peter E.; Lebron-Velilla, Ramon

2002-01-01

145

Radiated electromagnetic emissions of DC-DC converters

A new powering scheme is considered to be mandatory for the CMS tracker at SLHC. The baseline solution of CMS foresees the use of DC-DC converters, allowing to provide larger currents while reducing losses. An important component of most converters are inductors, which, however, tend to radiate the switching noise generated by the converter. The radiated emissions of several converters have been measured and simulated. In addition noise susceptibility measurements with radiated noise and present CMS hardware have been performed. A summary of the results will be presented.

Sammet, Jan Domenik

2010-01-01

146

Active Low Pass Filter based Efficient DC-DC Converter

Directory of Open Access Journals (Sweden)

Full Text Available In An efficient active filter based on-chip DC-DC voltage converter circuit is proposed which is used for application to distribute power supplies in multivoltage system. The circuit is appropriate for point-of-load voltage regulation due to an ultra area efficient architecture. Compare to other conventional voltage regulators, the proposed circuit is designed with small area and with no inductor or output capacitor. This is an alternative to classical LDO voltage regulators and hence, providing a means for distributing multiple local power supplies across an integrated circuit while maintaining high efficiency and fast response time within a small area. Thus, the performance of proposed active filter based DC-DC converter is analysed.

K.Raashmil *1

2014-04-01

147

High frequency resonant MOS-FET dc-dc converter

The authors explain the operation of a 100-W half-bridge resonant dc-dc converter, the method of determining the LC constants, and the condition of gate drive for achieving no-loss switching. Since the circuit operation is of a zero-volt-switching type, the switching loss at turn-off as well as turn-on can be zeroed by strengthening the gate drive circuit. It is confirmed that the LC constants can be determined by using a simple circuit model, and that setting a low resonant capacitor voltage is effective for reducing the main circuit loss. The characteristics of some dc-dc converters trial-manufactured on the basis of these results are shown.

Karube, K.; Nomura, T.; Nakano, T.

148

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

149

Radiated electromagnetic emissions of DC-DC converters

International Nuclear Information System (INIS)

For the CMS tracker at SLHC a new powering scheme is considered to be mandatory to allow the detector to provide at least the same performance as today at the LHC. The baseline solution of CMS foresees the use of DC-DC converters to provide larger currents with smaller losses. An important component of most converters are inductors which, however, tend to radiate the switching noise generated by the converter. The emissions of different inductors have been measured and simulated, the coil design has been optimized and noise susceptibility measurements, with present CMS hardware, have been performed. This article summarizes the results.

150

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

151

Design optimization for a half-bridge dc-dc converter

A nonlinear programming technique using penalty function method is employed for the minimum weight design of a half-bridge dc-dc buck power converter. The cost-effective computer-aided approach provides a minimum-weight design down to the details of the component level and concurrently meets all power-circuit performance requirements. Important design insights and guidelines are obtained to readily assess (1) the tradeoffs between weight and loss as the switching frequency is increased, (2) the optimum operating frequency range over which the total weight/loss is minimized, (3) the impact of device characteristics on the total weight and loss profile.

Wu, C. J.; Lee, F. C.; Balachandran, S.; Goin, H. L.

152

System Tests with DC-DC Converters for the CMS Silicon Strip Tracker at SLHC

The delivery of power is considered to be one of the major challenges for the upgrade of the CMS silicon strip tracker for SLHC. The inevitable increase in granularity and complexity of the device is expected to result in a power consumption comparable or even higher than the power consumption of todays' strip tracker. However, the space available for cables will remain the same. In addition, a further increase of the tracker material budget due to cables and cooling is considered inacceptable, as the performance of the CMS detector must not be compromised for the upgrade. Novel powering schemes such as serial powering or usage of DC-DC converters have been proposed to solve the problem. To test the second option, substructures of the current CMS silicon strip tracker have been operated for the first time with off-the-shelf DC-DC buck converters as well as with first prototypes of custom-designed DC-DC converters. The tests are described and the results are discussed.

Klein, K; Karpinski, W; Merz, J; Sammet, J

2008-01-01

153

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.

154

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

155

Low dose failures of hardened DC-DC power converters

Box-level total dose testing of the FOG (Fiber Optic Gyro) by IXSEA at ESA's GammabeamFacility were abruptly terminated at 8krad (Si) due to catastrophic failure (complete shutdown). This was unexpected because all components within the gyro were supposedly radiation tolerant. Further testing showed that the components responsible for the failure were two DC-DC converters, manufactured by Interpoint, that stopped regulating shortly before shutdown. This paper summarizes diagnostic test results for the converters to determine the underlying cause of the unexpected failure at low levels of radiation.

Lehman, J.; Yui, C.; Rax, B. G.; Miyahira, T. F.; Weideman, M.; Schrick, P.; Swift, G. M.; Johnston, A. H.

2002-01-01

156

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

157

A dc-dc converter has been developed to charge capacitors to 16 kV from a 400 V battery bank. It is designed to charge an 8.5 MJ bank nine times in 3 min. The converter is comprised of six modules, each producing 12.5 A of charging current, and an enclosure which houses the modules and provides control power and a master controller. The six 200 kW modules have a combined power rating of 1.2 MW. The pulse width modulation converter system operates at 24 kHz and contains inverters with power MOSFETs as the principal inverter components, 200 kW transformers and inductors, and full bridge rectifiers with fast recovery diodes. The converter modules have a volume power density of 1.0 MW/cu m and a mass power density of 1.2 kW/kg. The converter design and test results are described.

Homeyer, W. G.; Callanan, R. J.; Bowles, E. E.; Nerem, A.

1993-01-01

158

Single-Input Dual-Output (SIDO) Linear–Assisted DC/DC Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

This article describes a single-input dual output (SIDO) linear-assisted DC/DC converter. Linear-assisted DC/DC converters are structures that allow to take advantages of the two classic alternatives in the design of power supply systems: voltage linear regulators and switching DC/DC converters. Thanks to the combination of a switching converter and two voltage linear regulators, the proposed SIDO converter provides two independent outputs with suitable load and line regulations. In the prese...

Marti?nez Garci?a, Herminio; Silva-marti?nez, Jose?; Conesa Roca, Alfons; Poveda Lo?pez, Alberto

2008-01-01

159

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

160

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

161

Model-free control of dc/dc converters

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new "model-free" control methodology is applied for the first time to power converters, and in particular to a buck converter, and to a Cuk converter. We evaluate its performances regarding load and supply variations. Our approach, which utilizes "intelligent" PI controllers, does not require any converter identification while ensuring the stability and the robustness of the control synthesis. Simulation and experimental results show that, with a simple control structure, insensitivity to p...

Michel, Loi?c; Join, Ce?dric; Fliess, Michel; Sicard, Pierre; Che?riti, Ahmed

2010-01-01

162

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

163

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

164

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Ahmad Saudi Samosir; Nfn, Taufiq; Abdul Halim Mohd Yatim

2011-01-01

165

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

166

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

167

Artificial neural network control of sab dc/dc converter

International Nuclear Information System (INIS)

The latest development of power semiconductor devices enable the modern power electronic converters to withstand high voltage and high power applications. Power electronic converters are mostly periodic variable structure systems due to their switched operations. The main drawback of these converters is the generation of oscillations which are developed during the operation of the converters under nonlinear situations. To handle these nonlinearities, various researchers have proposed different control techniques. Power electronic designers are devoting in the further development of converter topologies and their control techniques. SAB (Single Active Bridge) DC/DC converter is a new topology recently introduced by Demetriades. This topology is used in high voltage and high power applications. Because of its smart features, SAB converter has recently drawn attention of many researchers. However, during the operation of SAB converter severe oscillations are generated. In this research work, a novel NNC (Neural Network Controller) model is developed for SAB converter to minimize oscillations generated during its operation. NNC is believed to be an advanced nonlinear and robust controller which has the ability to map the nonlinear behaviour in a negligible response time. The performance of SAB converter with NNC is tested under dynamic region by considering the reference voltage variation and duty ratio variation. The SAB converter is implemented and simulated in MATLAB/Sr is implemented and simulated in MATLAB/Simulink. The simulated results are presented. (author)

168

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

169

DC-DC converter for discharging energy storage magnets

A new DC-DC converter to control the output power delivered from a magnetic energy storage magnet or an equivalent current source is discussed. The circuit consists of: (1) highly coupled transformer (air or iron core) with coupling coefficient better than 0.95; (2) low frequency mechanical or superconducting switches (0.1 - 10 Hz) or high frequency (10 - 1000 Hz) GTO switches depending on the application; and (3) small voltage source (capacitor or battery) to control the output voltage. Two examples illustrating the application of this circuit are discussed. They are a step up dc current converter for use in uninterruptible power supplies and a step down one for use in discharging large current storage coil into a small current load. The efficiency expected to exceed 90%.

Eyssa, Yehia M.; Huang, Xianrui

1994-07-01

170

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

171

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

172

Large step-down DC-DC converters with reduced current stress

International Nuclear Information System (INIS)

In this paper, several DC-DC converters with large voltage step-down ratios are introduced. A simple modification in the output section of the conventional buck and quadratic converters can effectively extend the duty-cycle range. Only two additional components (an inductor and diode) are necessary for extending the duty-cycle range. The topologies presented in this paper show an improvement in the duty-cycle (about 40%) over the conventional buck and quadratic converters. Consequently, they are well suited for extreme step-down voltage conversion ratio applications. With extended duty-cycle, the current stress on all components is reduced, leading to a significant improvement of the system losses. The principle of operation, theoretical analysis, and comparison of circuit performances with other step-down converters is discussed regarding voltage and current stress. Experimental results of one prototype rated 40-W and operating at 100 kHz are provided in this paper to verify the performance of this new family of converters. The efficiency of the proposed converters is higher than the quadratic converters

173

High-frequency resonant transistor dc-dc converters

The design of a transistor dc-dc resonant converter operating at 200-300 kHz is presented, and the operation of a 500-W breadboard version is reported. Several configurations of both voltage-input and current-input type are described and illustrated with circuit diagrams and waveforms, and a full-bridge voltage-input resonant inverter using gate turnoff devices is analyzed in detail, using a piecewise linear approach to obtain design curves. The performance of the breadboard voltage-input half bridge using FET power switches is shown in graphs, demonstrating the low switching losses and transistor stresses achieved by lossless-snubber design. It is predicted that similar designs using bipolar transistors or GTOs can attain energy efficiencies greater than 90 percent. Applications to switching power supplies and battery chargers are suggested.

Steigerwald, R. L.

1984-05-01

174

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

175

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

International Nuclear Information System (INIS)

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.

176

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

177

Using discrete time state variable representation, a generalized computer-aided modeling and analysis of dc-dc converters is presented. The methodology provides exact modeling and is applicable to all types of power stages and duty-cycle control, including continuous and discontinuous inductor current operation. Converter stability, transient behavior and audio susceptibility can be analytically evaluated and predicted. The generalized theory of the proposed approach to converter modeling and analysis is presented first, followed by a demonstrative example applying the theory to a constant frequency buck converter operating in continuous and discontinuous inductor current mode. Excellent agreement with laboratory test data has been observed.

Iwens, R. P.; Lee, F. C.; Triner, J. E.

1977-01-01

178

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

179

Study of Chaos in the buck Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

A dc-dc buck converter controlled by naturallysampled, constant-frequency pulsewidth modulation in continuous conduction mode gives rise to a great variety of behavior, depending on the values of the parameters of the circuit. We analyze the one-periodic and two-periodic orbits which cross the voltage ramp once per cycle, and we study their stability by computing the characteristic multipliers associated with each one. Subharmonics, bifurcations, and the presence of a strange attractor are al...

Fossas Colet, Enric; Olivar, Gerard

1996-01-01

180

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

181

Subcontract Report: DC-DC Converter for Fuel Cell and Hybrid Vehicles.

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...

L. Zhu, L. D. Marlino

2007-01-01

182

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

183

Energy Technology Data Exchange (ETDEWEB)

A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

2014-09-09

184

CIECA - Application to current programmed switching Dc-Dc converters

The current injection equivalent circuit approach (CIECA) to modeling switching converter power stages is extended to model the current programmed converter power stages operating in fixed frequency, continuous inductor conduction mode. To demonstrate the method, modeling is carried out for the buck, boost, and buckboost converters to obtain small-signal linear equivalent circuit models which represent both input and output properties. The results of these analyses are presented in the form of linear equivalent circuit models as well as transfer functions. Though current programmed converters exhibit single-pole response, the addition of artificial ramp changes converters to exhibit well damped two-pole response. This has been investigated for the first time using CIECA. The results of these analyses are presented in the form of linear equivalent circuit models as well as transfer functions.

Chetty, P. R. K.

1982-09-01

185

Multi-cell DC-DC converters : modelling, analysis and control

International Nuclear Information System (INIS)

This paper is devoted to modeling of a two-cell DC/DC buck converter, to the analysis of its behavior and to the design of control methods that yield to improve its performances. Various numerical simulations and dynamical aspects of this system are illustrated in the time domain and in the parameter space. Without control, the system may present many undesirable behaviors such as sub-harmonics and chaotic oscillations. The proposed controllers are 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.

186

Power Network impedance effects on noise emission of DC-DC converters

International Nuclear Information System (INIS)

The characterization of electromagnetic noise emissions of DC-DC converters is a critical issue that has been analyzed during the desing phase of CMS tracker upgrade. Previous simulation studies showed important variations in the level of conducted emissions when DC-DC converters are loaded/driven by different impedances and power network topologies. Several tests have been performed on real DC-DC converters to validate the Pspice model and simulation results. This paper presents these test results. Conducted noise emissions at the input and at the output terminals of DC-DC converters has been measured for different types of power and FEE impedances. Special attention has been paid to influence on the common-mode emissions by the carbon fiber material used to build the mechanical structure of the central detector. These study results show important recommendations and criteria to be applied in order to decrease the system noise level when integrating the DC-DC.

187

Power Network impedance effects on noise emission of DC-DC converters

The characterization of electromagnetic noise emissions of DC-DC converters is a critical issue that has been analyzed during the desing phase of CMS tracker upgrade. Previous simulation studies showed important variations in the level of conducted emissions when DC-DC converters are loaded/driven by different impedances and power network topologies. Several tests have been performed on real DC-DC converters to validate the Pspice model and simulation results. This paper presents these test results. Conducted noise emissions at the input and at the output terminals of DC-DC converters has been measured for different types of power and FEE impedances. Special attention has been paid to influence on the common-mode emissions by the carbon fiber material used to build the mechanical structure of the central detector. These study results show important recommendations and criteria to be applied in order to decrease the system noise level when integrating the DC-DC.

Esteban, M. C.; Arteche, F.; Iglesias, M.; Gimeno, A.; Arcega, F. J.; Johnson, M.; Cooper, W. E.

2012-01-01

188

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

189

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

190

The upgrade of the Large Hadron Collider (LHC) experiments at CERN sets new challenges for the powering of the detectors. One of the powering schemes under study is based on DC-DC buck converters mounted on the front-end modules. The hard environmental conditions impose strict restrictions to the converters in terms of low volume, radiation and magnetic field tolerance. Furthermore, the noise emission of the switching converters must not affect the performance of the powered systems. A study of the sources and paths of noise of a synchronous buck converter has been made for identifying the critical parameters to reduce their emissions. As proof of principle, a converter was designed following the PCB layout considerations proposed and then used for powering a silicon strip module prototype for the ATLAS upgrade, in order to evaluate their compatibility.

Fuentes, C; Michelis, S; Blanchot, G; Allongue, B; Faccio, F; Orlandi, S; Kayal, M; Pontt, J

2011-01-01

191

The characterstics of a dc/dc converter at different stages of a spacecraft project were surveyed in order to offset the constraints of a strict schedule. In particular, the weight and efficiency of these converters were determined theoretically, enabling...

A. Barnaba

1976-01-01

192

Development of a green mode DC/DC converter available to portable nuclear instrument

International Nuclear Information System (INIS)

A green mode DC/DC converter was developed which suitable to the portable nuclear instrument which is powered by battery and is sometime at stand-by mode. Some updated control approaches such as pseudo-resonant type power supply control and synchronous rectification were adopted to makethe DC/DC converter operate with low power consumption and high efficiency. The test results the battery can be prolonged with this converter. (authors)

193

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

194

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

195

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

196

Operating Voltage and Loss Analysis of a Bi-Directional Isolated DC/DC Converter

This paper describes a bi-directional isolated dc/dc converter having a high-frequency transformer with a unity turn ratio, where the input and output dc voltages are different from each other. Theoretical analysis reveals that power loss in the dc/dc converter, as well as peak current flowing in the high-frequency transformer and auxiliary inductors, imposes limitations on the maximum transferable power. The 10-kW, 20-kHz dc/dc converter designed and constructed in this paper is operated with one dc voltage fixed to 320V and the other ranging between 180V and 360V without excessively increased power loss. The effect of the so-called “dead time” on the operating performance is also discussed in this paper. Such wide range of dc voltage may bring about a various application fields to the dc/dc converter.

Inoue, Shigenori; Akagi, Hirofumi

197

Directory of Open Access Journals (Sweden)

Full Text Available 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 regulated output voltage ripples can be obtained. The active clamping circuit used in this model absorbs the turn off voltage spikes hence low voltage devices with low on state resistance can be used.Voltage doubler circuits will give double the output voltage than normal with smaller transformer turns ratio and flexibility. The proposed method is simulated in MATLAB for verifying the accuracy of the proposed design.

Sona P

2014-02-01

198

Control of the DC-DC Converter used into Energy Generation System

International Nuclear Information System (INIS)

This paper presents an investigation of the DC-DC Converter controller used into Energy Generation System. The full bridge is used into an Energy Generation System (EGS) as second power interface between the energy source and the high DC bus. The simulation results show that the DC-DC Converter behavior can be improved using a well designed PI control surface. The used Simulink models for the EGS blocks and some design considerations are presented, too. (authors)

199

Non-Dissipative Snubber for Rectifying Diodes in a High-Power DC-DC Converter

In a high output current DC-DC converter, most power dissipation comes from rectifying diodes. In this paper, a novel non-dissipative snubber is proposed for the rectifying diodes to reduce the power dissipation of the rectifying circuit. This snubber is applied to the center-tapped rectifying circuit in a full-bridge DC-DC converter. As a result, the efficiency has been improved to 91% on the prototype of 12V/80A output.

Hirokawa, Masahiko; Ninomiya, Tamotsu

200

Design and Implementation of a FLC for DC-DC Converter in a Microcontroller for PV System

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the design and implementation of a simple fuzzy logic controller (FLC for a DC-DC buck converter based on the PIC18F4550 microcontroller to control the lead acid battery charging voltage in solar cells applications. For cost consideration, an inexpensive 8-bit microcontroller is selected to program and implement the FLC proportional-integral. The obtained simulation and experimental results show the viability of the controller with a variation on the load of the buck converter showing a good performance on the design of the FLC, and it has also a smooth response with a small overshoot. The DC-DC converter designed in this work can be found applications in low cost photovoltaic (PV systems, although in the literature has been already reported this kind of devices with a better response [3-4], however these use a expensive microcontroller or its designs are very complex, and where these are not necessary for this kind of applications. Finally, a prototype PV system with 100 V/6 A has been implemented for verifying the feasibility of the CD-CD converter.

Abel García-B.

2013-07-01

201

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)

202

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

203

Efficiency and Regulation of Commercial Low Power DC/DC Converter Modules at Low Temperatures

DC/DC converters that are capable of operating at cryogenic temperatures are anticipated to play an important role in the power systems of future NASA deep space missions. Design of these converters to survive cryogenic temperatures will improve the power system performance, and reduce development and launch costs. At the NASA Glenn Research Center Low Temperature Electronics Laboratory, several commercial off-the-shelf dc/dc converter modules were evaluated for their low temperature performance. Various parameters were investigated as a function of temperature, in the range of 20 C to -190 C. Data pertaining to the efficiency and voltage regulation of the tested converters is presented and discussed.

Elbuluk, Malik E.; Gerber, Scott; Hammoud, Ahmad; Patterson, Richard L.

2000-01-01

204

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

205

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

206

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

207

Test Results of Selected Commercial DC/DC Converters under Cryogenic Temperatures - A Digest

DC/DC converters are widely used in space power systems in the areas of power management and distribution, signal conditioning, and motor control. Design of DC/DC converters to survive cryogenic temperatures will improve the power system performance, simplify design, and reduce development and launch costs. In this work, the performance of nine COTS modular, low-tomedium power DC/DC converters was investigated under cryogenic temperatures. The converters were evaluated in terms of their output regulation, efficiency, and input and output currents. At a given temperature, these properties were obtained at various input voltages and at different load levels. A summary on the performance of the tested converters was given. More comprehensive testing and in-depth analysis of performance under long-term exposure to extreme temperatures are deemed necessary to establish the suitability of these and other devices for use in the harsh environment of space exploration missions.

Patterson, Richard; Hammoud, Ahmad

2010-01-01

208

DC-DC converters with reduced mass for trackers at the HL-LHC

International Nuclear Information System (INIS)

The development at CERN of low noise DC-DC converters for the powering of front-end systems enables the implementation of efficient powering schemes for the physics experiments at the HL-LHC. Recent tests made on the ATLAS short strip tracker modules confirm the full electromagnetic compatibility of the DC-DC converter prototypes with front-end detectors. The integration of the converters in the trackers front-ends needs to address also the material budget constraints. The impact of the DC-DC converters onto the material budget of the ATLAS tracker modules is discussed and mass reduction techniques are explored, leading to a compromise between electromagnetic compatibility and mass. Low mass shield implementations and Aluminum core inductors are proposed. Also, the impact on emitted noise due to a size reduction of critical components is discussed. Finally, material reduction techniques are discussed at the board layout and manufacturing levels.

209

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

210

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 component...

NIMMY JOSEPH

2013-01-01

211

High power density dc/dc converter: Component selection and design

Further work pertaining to design considerations for the new high power, high frequency dc/dc converters is discussed. The goal of the project is the development of high power, high power density dc/dc converters at power levels in the multi-kilowatt to megawatt range for aerospace applications. The prototype converter is rated for 50 kW at a switching frequency of 50 kHz, with an input voltage of 200 Vdc and an output of 2000 Vdc. The overall power density must be in the vicinity of 0.2 to 0.3 kg/kW.

Divan, Deepakraj M.

1989-01-01

212

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

213

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Sreenivasappa Veeranna Bhupasandra; Udaykumar Yaragatti

2010-01-01

214

ZVS Bridge Leg and ZCS Bridge Leg DC-DC Converter with Tapped Inductor Filter

In this paper, a novel full-bridge soft-switching phase-shifted PWM DC-DC power converter circuit is presented. A tapped inductor filter is implemented in the proposed converter topology to achieve soft switching commutation for the active power switches under wide load variation range, to minimize circulating current without using additional resonant circuit and/or auxiliary switching devices. The effectiveness of the proposed soft-switching DC-DC power converter is verified in experiment with 2kW-100kHz breadboard circuit using IGBTs.

Moisseev, Serguei; Hamada, Satoshi; Nakaoka, Mutsuo

215

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

216

Dynamic analysis of the input-controlled buck converter fed by a photovoltaic array

Digital Repository Infrastructure Vision for European Research (DRIVER)

The control of the input voltage of DC-DC converters is frequently required in photovoltaic applications. In this special situation, unlike conventional converters, the output voltage is constant and the input voltage is controlled. This paper deals with the analysis and the control of the buck converter with constant output voltage and variable input.O controle da tensão de entrada de conversores DC-DC é freqüentemente necessário em aplicações com energia fotovoltaica. Nesta situa?...

Marcelo Gradella Villalva; Ernesto Ruppert Filho

2008-01-01

217

Directory of Open Access Journals (Sweden)

Full Text Available In this paper two DC-DC converters connected in parallel with the purpose of load sharing by applying droop method is considered. This method requires no communication interconnection and compensates for converter parameter variations and imbalances in line impedance. The DC-DC converter input source can be any DC source such as photovoltaic module and wind turbine or fuel cell and it is a closed loop system. In this work proportional-integral (PI controller, will have their performance evaluated to control the paralleled converters connected to DC micro-grid. The PI controller is tuned by particle swarm optimization (PSO method. The designing of stable DC-DC converter with primary droop current-sharing control, the stability of the interconnected parallel DC-DC converter system was studied. When the cable resistance of the paralleled DC converters differs, the interconnected system might be unstable and due to this the uneven load sharing occurs. To resolve this issue to some extent without the use of communication lines, a novel technique is applied to parallel DC boost converter in order to optimize the large uneven current sharing. The parallel converter must provide an even load sharing and secondly redundancy. Simulation results are presented in the paper using Mat lab/Simulink to confirm the concept.

Abhimanyu Kumar Yadav

2013-11-01

218

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

219

Double Two Switch Forward Soft Switching PWM DC-DC Converter

A novel prototype of a double two-switch forward transformer linked zero-voltage and zero-current mode soft-switching (ZVZCS) pulse width modulation (PWM) DC-DC power converter using IGBTs for high power applications is presented. Based on a conventional two-switch forward transformer linked PWM DC-DC converter topology, this converter circuit configuration doesn't include any complex auxiliary resonant circuit. Combining two identical two-switch forward type DC-DC power conversion circuits with a tapped-inductor type DC smoothing filter into a power DC-DC conversion system makes it possible to achieve soft-switching conditions for the active power switches with aid of lossless snubber capacitors and transformer parasitic inductors. Lowered peak voltage across the power switching devices and their related peak current stresses, no transformer saturation effect, reducing of idle and circulating currents through circuit components are practically attained for this converter. This soft-switching PWM DC-DC power converter has some unique advantages such as better power conversion efficiency, lowered output DC ripple current, high power density, constant frequency PWM control scheme, cost effective and wide soft-switching operation range under load variations and PWM regulation settings for high power utilizations. The basic operating principle of the new soft switching power converter treated here is illustrated with approximate periodic steady-state circuit analysis for each mode equivalent circuit. The practical effectiveness of the proposed soft-switching DC-DC power converter is confirmed by the simulation results and is experimentally evaluated on basis of 500W-100kHz breadboard setup using the fast switching IGBTs.

Hamada, Satoshi; Moisseev, Serguei; Koudriavtsev, Oleg; Nakaoka, Mutsuo

220

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

221

Controlling DC-DC converters by chaos-based pulse width modulation to reduce EMI

International Nuclear Information System (INIS)

In this paper, periodic and chaotic behaviors of DC-DC converters under certain parametric conditions are simulated, experimentally verified, and analyzed. Motivated by the work of J.H.B. Deane and D.C. Hamill in 1996, where chaotic phenomena are useful in suppressing electromagnetic interference (EMI) by adjusting the parameters of the DC-DC converter and making it operate in chaos, a chaos-based pulse width modulation (CPWM) is proposed to distribute the harmonics of the DC-DC converters continuously and evenly over a wide frequency range, thereby reducing the EMI. The output waves and spectral properties of the EMI are simulated and analyzed as the carrier frequency or amplitude changes with regard to different chaotic maps. Simulation and experimental results are given to illustrate the effectiveness of the proposed CPWM, which provides a good example of applying chaos theory in engineering practice.

222

Modelling and Simulation of Digital Compensation Technique for dc-dc Converter by Pole Placement

A thorough and effective analysis of the dc-dc converters is carried out in order to achieve the system stability and to improve the dynamic performance. A small signal modelling based on state space averaging technique for dc-dc converters is carried out. A digital state feedback gain matrix is derived by pole placement technique in order to achieve the stability of a completely controllable system. A prediction observer for the dc-dc converters is designed and a dynamic compensation (observer plus control law) is provided using separation principle. The output is very much improved with zero output voltage ripples, zero peak overshoot, and much lesser settling time in the range of ms and with higher overall efficiency (>90 %).

Shenbagalakshmi, R.; Sree Renga Raja, T.

2014-07-01

223

Controlling DC-DC converters by chaos-based pulse width modulation to reduce EMI

Energy Technology Data Exchange (ETDEWEB)

In this paper, periodic and chaotic behaviors of DC-DC converters under certain parametric conditions are simulated, experimentally verified, and analyzed. Motivated by the work of J.H.B. Deane and D.C. Hamill in 1996, where chaotic phenomena are useful in suppressing electromagnetic interference (EMI) by adjusting the parameters of the DC-DC converter and making it operate in chaos, a chaos-based pulse width modulation (CPWM) is proposed to distribute the harmonics of the DC-DC converters continuously and evenly over a wide frequency range, thereby reducing the EMI. The output waves and spectral properties of the EMI are simulated and analyzed as the carrier frequency or amplitude changes with regard to different chaotic maps. Simulation and experimental results are given to illustrate the effectiveness of the proposed CPWM, which provides a good example of applying chaos theory in engineering practice.

Li Hong [Department of Mathematics and Computer Science, FernUniversitaet in Hagen, 58084 Hagen (Germany)], E-mail: hong.li@FernUni-Hagen.de; Zhang Bo [School of Electric Power, South China University of Technology, Guangzhou (China); Li Zhong; Halang, Wolfgang A. [Department of Mathematics and Computer Science, FernUniversitaet in Hagen, 58084 Hagen (Germany); Chen Guanrong [Department of Electronic Engineering, City University of Hong Kong, Hong Kong (China)

2009-11-15

224

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

225

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

226

Soft switching DC/DC converter using controlled output rectifier with auxiliary circuit

Directory of Open Access Journals (Sweden)

Full Text Available Auxiliary circuit for DC/DC converter withcontrolled output rectifier is presented in this paper.Soft switching for power switches of the inverter isachieved by using controlled output rectifier and softswitching of the controlled rectifier by using losslessauxiliary circuit. The principle of converter operationis explained and analyzed and experimental results onthe laboratory model are presented.

DUDRIK Jaroslav

2010-05-01

227

Soft switching DC/DC converter using controlled output rectifier with auxiliary circuit

Digital Repository Infrastructure Vision for European Research (DRIVER)

Auxiliary circuit for DC/DC converter withcontrolled output rectifier is presented in this paper.Soft switching for power switches of the inverter isachieved by using controlled output rectifier and softswitching of the controlled rectifier by using losslessauxiliary circuit. The principle of converter operationis explained and analyzed and experimental results onthe laboratory model are presented.

Dudrik, Jaroslav; Bodor, Marcel; Trip, Daniel Nistor

2010-01-01

228

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

229

A 10 kW dc-dc converter using IGBTs with active snubbers

This full bridge dc-dc converter employs zero voltage switching (ZVS) on one leg and zero current switching (ZCS) on the other. This technique produces exceptionally low IGBT switching losses through the use of an active snubber that recycles energy back to the source. Experimental results are presented for a 10 kW, 20 kHz converter.

Masserant, Brian J.; Shriver, Jeffrey L.; Stuart, Thomas A.

1993-07-01

230

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.

231

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

Energy Technology Data Exchange (ETDEWEB)

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. (author)

Adib, Ehsan; Farzanehfard, Hosein [Dept. of Electrical and Computer Engineering, Isfahan Univ. of Technology (Iran)

2009-12-15

232

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

233

Half bridge ZVS DC-DC converter with DCS PWM active clamp technique

Digital Repository Infrastructure Vision for European Research (DRIVER)

Half bridge (HB) dc–dc converter is an attractive topology for middle power level applications owing to its simplicity. This paper presents 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 one of the two switches without adding extra components and without adding asymmetric penalties of the complementary control. The concept of this new control scheme is shifting one o...

JANAPATI SIVAVARA PRASAD

2012-01-01

234

Design and Analysis of a Novel DC-DC Converter Fed from Multiple Voltage Sources

Directory of Open Access Journals (Sweden)

Full Text Available A novel DC-DC converter is proposed in the work carried out powered from multiple sources. The power conversion circuit consists of less number of active power switches with associated passive components. By adjusting the duty-ratio of the active power switch, the power sharing between two power sources and proposed three sources; as well as the output voltage regulation can be made. The simulation and experimental results for conventional two sources and proposed three sources fed DC-DC converter are presented in this paper.

M.R.Rashmi

2012-06-01

235

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

236

Using Nyquist or Nyquist-Like Plot to Predict Three Typical Instabilities in DC-DC Converters

By transforming an exact stability condition, a new Nyquist-like plot is proposed to predict occurrences of three typical instabilities in DC-DC converters. The three instabilities are saddle-node bifurcation (coexistence of multiple solutions), period-doubling bifurcation (subharmonic oscillation), and Neimark bifurcation (quasi-periodic oscillation). In a single plot, it accurately predicts whether an instability occurs and what type the instability is. The plot is equivalent to the Nyquist plot, and it is a useful design tool to avoid these instabilities. Nine examples are used to illustrate the accuracy of this new plot to predict instabilities in the buck or boost converter with fixed or variable switching frequency.

Fang, Chung-Chieh

2012-01-01

237

Isolated Bidirectional DC–DC Converter for SuperCapacitor Applications

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

238

Kvasiresonant DC-DC Converter with Switching at Zero Current - Part 1

Directory of Open Access Journals (Sweden)

Full Text Available A kvasiresonant DC - DC converter and its control circuits are proposed. The relations useful for design of the converter will be deduced in the part 2. The fundamental idea of the converter is the switching -on and -off a transistor at zero current. In this way the switching losses are eliminated. It enables to design a converter with a large output power (several kW, high switching frequency (about 200 kHz, very good efficiency and low radiation.

P. Vorel

1998-04-01

239

International Nuclear Information System (INIS)

This paper investigates the interest focused on employing parallel connected dc-dc converter with high tracking effectiveness under wide variation in environmental conditions (Insolation) and wide load variation. dc-dc converter is an essential part of the stand alone PV system. Paper also presents an approach on how duty cycle for maximum power position (MPP) is adjusted by taking care of varying load conditions and without iterative steps. Synchronized PWM pulses are employed for the converter. High tracking efficiency is achieved with continuous input and inductor current. In this approach, the converter can he utilized in buck as well in boost mode. The PV system simulation was verified and experimental results were in agreement to the presented scheme. (authors)

240

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

241

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

242

A novel trajectory prediction control for proximate time-optimal digital control DC—DC converters

The purpose of this paper is to present a novel trajectory prediction method for proximate time-optimal digital control DC—DC converters. The control method provides pre-estimations of the duty ratio in the next several switching cycles, so as to compensate the computational time delay of the control loop and increase the control loop bandwidth, thereby improving the response speed. The experiment results show that the fastest transient response time of the digital DC—DC with the proposed prediction is about 8 ?s when the load current changes from 0.6 to 0.1 A.

Qing, Wang; Ning, Chen; Shen, Xu; Weifeng, Sun; Longxing, Shi

2014-09-01

243

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

244

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

245

Comments on "Bifurcations in DC-DC Switching Converters: Review of Methods and Applications"

In a review paper [1] (El Aroudi, et al., 2005), two stability conditions for DC-DC converters are presented. However, these two conditions were published years earlier at least in a journal paper [2] (Fang and Abed, 2001). In this note, the similar texts of [1] and [2] are compared.

Fang, Chung-Chieh

2012-01-01

246

Experimental study of controlling chaos in a DC-DC boost converter

International Nuclear Information System (INIS)

This paper presents a delayed feedback control scheme for eliminating chaotic behaviour in a peak current-mode controlled DC-DC boost converter operating in the continuous current conduction mode. Experimental results and FORTRAN simulations show the effectiveness and robustness of the scheme.

247

Computer-aided analysis and simulation of switched dc-dc converters

State space techniques are employed to derive an equivalent nonlinear recurrent time-domain model that describes the switched dc-dc converter behavior exactly. This model is employed effectively to analyze both large signal behavior by propagating the recurrence equation and matching boundary conditions through digital computation and small signal behavior by linearizing it about the equilibrium state.

Lee, F. C.; Yu, Y.

1978-01-01

248

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

249

A Novel PPFHB Bidirectional DC-DC Converter for Supercapacitor Application

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

250

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ar...

Meng, Lexuan; Dragicevic, Tomislav; Guerrero, Josep M.; Vasquez, Juan Carlos

2013-01-01

251

Soft Switched Multi-Output PWM DC-DC Converter

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a new soft switched cell that overcomes most of the drawbacks of the normal "hard switched-pulse width modulation" converter is proposed to contrive a new family of soft switched PWM converters. All of the semiconductor devices in this converter are turned on and off under exact or near zero voltage switching (ZVS and/or zero current switching (ZCS. No additional voltage and current stresses on the main switch and main diode occur. A push-pull converter equipped with the proposed snubber cell is analyzed in detail. The predicted operation principles and theoretical analysis of the presented converter are verified with a prototype of a 50W PWM push-pull multi-output converter with insulated MOSFET and for regulation of slave outputs magnetic amplifier post regulators are considered as post regulators. Moreover; this multioutput converter has a simple structure, low cost, and ease of control circuitry.

Rashmi Sharma

2013-07-01

252

DC-DC power converter research for Orbiter/Station power exchange

This project was to produce innovative DC-DC power converter concepts which are appropriate for the power exchange between the Orbiter and the Space Station Freedom (SSF). The new converters must interface three regulated power buses on SSF, which are at different voltages, with three fuel cell power buses on the Orbiter which can be at different voltages and should be tracked independently. Power exchange is to be bi-directional between the SSF and the Orbiter. The new converters must satisfy the above operational requirements with better weight, volume, efficiency, and reliability than is available from the present conventional technology. Two families of zero current DC-DC converters were developed and successfully adapted to this application. Most of the converters developed are new and are presented.

Ehsani, M.

1993-01-01

253

ZVZCS PWM DC-DC Converter with Energy Recovery Clamp

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents research motivated by industrial demand for special traction drive topology devoted tominimization of traction transformer weight against topology with classical 50Hz traction transformer. The special tractiondrive topology for AC power systems consists of input high voltage trolley converter (single phase matrix converter) –middle frequency transformer – output converter - traction motor has been described. The main attention has been given tothe control algorithm of ...

Vladimir Ruscin; Jaroslav Durdik

2008-01-01

254

Symmetrical multilevel converters with two quadrant DC-DC feeding

Digital Repository Infrastructure Vision for European Research (DRIVER)

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; Rufer, Alfred

2008-01-01

255

Symmetrical multilevel converters with two quadrant DC-DC feeding

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

256

ZVZCS PWM DC-DC Converter with Energy Recovery Clamp

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents research motivated by industrial demand for special traction drive topology devoted tominimization of traction transformer weight against topology with classical 50Hz traction transformer. The special tractiondrive topology for AC power systems consists of input high voltage trolley converter (single phase matrix converter –middle frequency transformer – output converter - traction motor has been described. The main attention has been given tothe control algorithm of the traction topology (inserting of NULL vector of matrix converter and Two-value control ofsecondary active rectifier.

Jaroslav Durdik

2008-01-01

257

Full Wave Mode ZVT-PWM DC-DC Converters

Energy Technology Data Exchange (ETDEWEB)

This paper proposes a full wave model ZVT-PWM boost converter. The converter with the auxiliary switch in a full wave mode makes possible soft switching operation of all switches including the auxiliary switch whereas the auxiliary switch is turned of with hard switching in the conventional converter. Therefore, the proposed converter reduces the turn-off switching loss and switching noise of the auxiliary switch without additional passive and/or active elements and high power density system can be realized. (author). 5 refs., 10 figs., 2 tabs.

Kim, Tae Woo; Ahn, Hee Wook; Kim, Hack Sung [Kumoh National University of Technology, Kumi (Korea)

2001-06-01

258

Pulse-width modulated DC-DC power converters

This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

Kazimierczuk, Marian K

2008-01-01

259

Modelling the buck-type converter transient response with pulsating load

The analysis and modeling of buck type converters is described. Load variations are considered like any other variable in the system. Continuous time models which enable prediction of the transient response of the converter are proposed. Practical results are presented to validate analytical predictions derived from the model. The proposed method can be used in other dc-dc converter topologies.

Arau, J.; Cezon, J.; Aldana, F.; Uceda, J.

1989-08-01

260

Improvement of burst-mode control of piezoelectric transformer based DC/DC converter

International Nuclear Information System (INIS)

Burst-mode operation is adopted sometimes in piezoelectric transformer based converters for two major purposes: (1) to achieve voltage regulation in DC/DC converters and (2) to achieve dimming control in backlight inverters. Burst-mode control enables the converter to operate at a constant switching frequency as well as to maintain good efficiency at light load conditions. However, in practice, the piezoelectric transformer cannot instantly stop vibrating in the burst-mode due to its high quality factor. The delay in the output voltage change resulting from this behavior influences the accuracy of the regulation. This paper proposes a control strategy to make the piezoelectric transformer stop more quickly so as to enhance the accuracy of burst-mode control. The proposed method only modifies the control signal of the burst-mode driving circuit. The proposed control strategy is verified by experiments in a step-down 9 W DC/DC converter. (paper)

261

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

262

Cryogenic Evaluation of an Advanced DC/DC Converter Module for Deep Space Applications

DC/DC converters are widely used in power management, conditioning, and control of space power systems. Deep space applications require electronics that withstand cryogenic temperature and meet a stringent radiation tolerance. In this work, the performance of an advanced, radiation-hardened (rad-hard) commercial DC/DC converter module was investigated at cryogenic temperatures. The converter was investigated in terms of its steady state and dynamic operations. The output voltage regulation, efficiency, terminal current ripple characteristics, and output voltage response to load changes were determined in the temperature range of 20 to -140 C. These parameters were obtained at various load levels and at different input voltages. The experimental procedures along with the results obtained on the investigated converter are presented and discussed.

Elbuluk, Malik E.; Hammoud, Ahmad; Gerber, Scott S.; Patterson, Richard

2003-01-01

263

Improvement of burst-mode control of piezoelectric transformer based DC/DC converter

Burst-mode operation is adopted sometimes in piezoelectric transformer based converters for two major purposes: (1) to achieve voltage regulation in DC/DC converters and (2) to achieve dimming control in backlight inverters. Burst-mode control enables the converter to operate at a constant switching frequency as well as to maintain good efficiency at light load conditions. However, in practice, the piezoelectric transformer cannot instantly stop vibrating in the burst-mode due to its high quality factor. The delay in the output voltage change resulting from this behavior influences the accuracy of the regulation. This paper proposes a control strategy to make the piezoelectric transformer stop more quickly so as to enhance the accuracy of burst-mode control. The proposed method only modifies the control signal of the burst-mode driving circuit. The proposed control strategy is verified by experiments in a step-down 9 W DC/DC converter.

Vasic, Dejan; Liu, Yuan-Ping; Schwander, Denis; Costa, François; Wu, Wen-Jong

2013-05-01

264

Reconfigurable digital controller for a buck converter based on FPGA

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents a complete digitally controlled dc-dc buck converter performed by FPGA circuitry. All tasks, analog to digital conversion, control algorithm and pulse width modulation, were implemented in the FPGA. This approach enables high-speed dynamic response and programmability by the controller, without external passive components. In addition, the controller's structure can be easily changed with out external components. The applied algorithm enables a switching frequency of 100 kHz.

Milanovic?, Miro; Truntic?, Mitja; S?libar, Primoz?; Dolinar, Drago

2012-01-01

265

Buck-boost converter with fractional control for electric vehicles

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, non-integer order control is applied to improve the performance of a buck-boost dc-dc power converter with ultracapacitor based on state feedback techniques. The approach is based on stabilization in the Lyapunov's sense for linear rational-order systems. The ultracapacitor can overcome the classical problems of energy losses due to the use of batteries, giving more accuracy, autonomy and efficiency to the electrical vehicles.

Marti?nez Gonza?lez, Rube?n; Bolea Monte, Yolanda; Grau Saldes, Antoni; Marti?nez Garci?a, Herminio

2010-01-01

266

Comparative Study of PI Controlled and Fuzzy Controlled Buck Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main objective of this paper is to compare the performance between fuzzy controller and proportional integral controller in improving the performance of the DC-DC Buck Converter. The evaluation of the output has been carried out and compared by software simulation using MATLAB. This paper also evaluates the stability of the system with fuzzy controller and PI controller and concludes that the fuzzy controller is able to achieve faster transient response, has major stable steady state resp...

Neetu Sharma, Dr Pradyumn Chaturvedi

2013-01-01

267

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 variations and input changes.

Swarada S. Muley

2013-11-01

268

Dynamics and stability issues of a single-inductor dual-switching DC-DC converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

A single-inductor two-input two-output power electronic dc–dc converter can be used to regulate two generally nonsymmetric positive and negative outputs by means of a pulsewidth modulation with a double voltage feedback. This paper studies the dynamic behavior of this system. First, the operation modes and the steady-state properties of the converter are addressed, and, then, a stability analysis that includes both the power stage and control parameters is carried out. Different bifur...

Moreno Font, Vanessa; El Aroudi, Abdelali; Calvente, Javier; Giral, Roberto; Benadero Garci?a-morato, Luis

2010-01-01

269

A Versatile Step-Up/Step-Down Switched-Capacitor-Based DC-DC Converter

For battery-powered electronic products, one way to extend battery life is to use a versatile step-up/step-down DC-DC converter. A new versatile step-up/step-down switched-capacitor-based converter structure is proposed, and its efficiency is analyzed. In the step-down case, the efficiency is the same as, or even better than the efficiency of linear regulators.

Wei, Chia-Ling; Wu, Lu-Yao; Yang, Hsiu-Hui; Tsai, Chien-Hung; Liu, Bin-Da; Chang, Soon-Jyh

270

Steady state analysis of class E resonant dc-dc converter regulated under fixed switching frequency

Analytical and experimental results are presented for a new type of class E resonant dc-dc converter which is regulated by an auxiliary switch. The switching frequency of the converter is fixed. The analysis gives the permissible area for the operation mode with very low switching losses as well as the steady-state characteristics in this mode. Experiments on a 1-MHz 5-V 25-W breadboard regulator verify the results obtained theoretically. The measured efficiency is up to 83 percent.

Harada, Koosuke; Gu, Wen-Jian

271

Predictive Trailing-Edge Modulation Average Current Control in DC-DC Converters

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper investigates predictive digital average current control (PDACC) in dc/dc converters using trailing-edge modulation (TEM). The study is focused on the recurrence duty cycle equation and then stability analysis is performed. It is demonstrated that average current control using trailing-edge modulation is stable on the whole range of the duty cycle and thus design problems are highly reduced. The analysis is carried out in a general manner, independent of converter topology and th...

Lascu, D.; Draghici, D.

2013-01-01

272

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

273

The upgrade of the Large Hadron Collider (LHC) experiments at CERN sets new challenges for the powering of the detectors. One of the powering schemes under study is based on DC-DC buck converters mounted on the front-end modules. The hard environmental conditions impose strict restrictions to the converters in terms of low volume, radiation and magnetic field tolerance. Furthermore, the noise emission of the switching converters must not affect the performance of the powered systems. A study of the sources and paths of noise of a synchronous buck converter has been made for identifying the critical parameters to reduce their emissions. As proof of principle, a converter was designed following the PCB layout considerations proposed and then used for powering a silicon strip module prototype for the ATLAS upgrade, in order to evaluate their compatibility.

Fuentes Rojas, Cristian Alejandro; Blanchot, G

2011-01-01

274

Bifurcation and Chaos in a Pulse Width modulation controlled Buck Converter

DEFF Research Database (Denmark)

Power electronic system with pulse width modulation (PWM) control is studied. Behaviour characteristic for a nonlinear dynamical system is observed and theoretically explained. A DC-DC buck converter controlled by a voltage feedback is taken as an example. The studied system is described by a system of piecewise-smooth nonautonomous differential equations. The research are focused on chaotic oscillations analysis and analytical search for bifurcations dependent on parameter. The most frequent route to chaos by the period doubling is observed in the second order DC-DC buck converter. Other bifurcations as a complex behaviour in power electronic system evidence are also described. In order to verify theoretical study the experimental DC-DC buck converter was build. The results obtained from three sources were presented and compared. A very good agreement between theory and experiment was observed.

Kocewiak, Lukasz; Bak, Claus Leth

2007-01-01

275

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

276

The state-space average approach to modeling switching converter power stages is extended to model the current programmed converter power stages operating in fixed-frequency discontinuous conduction mode. To demonstrate the method, the modeling is carried out for the buck converter. The analysis reveals an instability in the buck converter (open loop) when it is operated at an output-to-input voltage ratio of equal to or greater than two-thirds. The results of these analyses as well as buck converter instability are experimentally verified. A remedy has been suggested and implemented successfully to eliminate the potential instability.

Chetty, P. R. K.

277

PHOTOVOLTAIC BASED HIGH-EFFICIENCY SINGLE-INPUT MULTIPLE-OUTPUT DC-DC CONVERTER

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this paper is to develop a photo voltaic power generation based high-efficiency multiple-output dc–dc converter. The proposed converter can boost the voltage of a low-voltage input power source to a controllable high-voltage dc bus and middle-voltage output terminals. In this paper, a coupled-inductor based dc–dc converter scheme utilizes only one power switch with the properties of voltage clamping and soft switching, and the corresponding device specifications are adequately designed. As a result, the objectives of high-efficiency power conversion, high step up ratio, and various output voltages with different levels can be obtained.

J.Kondalaiah?

2014-10-01

278

Development of DC-DC converters for the upgrade of the CMS pixel detector

International Nuclear Information System (INIS)

Around 2017, the pixel detector of the CMS experiment at LHC will be upgraded. The amount of current that has to be provided to the front-end electronics is expected to increase by a factor of two. Since the space available for cables is limited, this would imply unacceptable power losses in the available supply cables. Therefore it is foreseen to place DC-DC converters close to the front-end electronics, allowing to provide the power at higher voltages and thereby to facilitate the supply of the required currents with the present cable plant. The talk introduces the foreseen powering scheme of the pixel upgrade and summarizes the results of system test measurements with CMS pixel sensor modules, radiation tolerant DC-DC converters and the full power supply chain of the pixel detector. In addition, measurements of the converter efficiency and performance before, after and during thermal cycling are presented.

279

Voltage Tracking of a DC-DC Flyback 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 Flyback converter that will step up a 12V DC and applied it on brushless DC motor with 12 and 24V dc. 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 Flyback 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.

Wahyu Mulyo Utomo

2012-01-01

280

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

281

Development of DC-DC converters for the upgrade of the CMS pixel detector

Energy Technology Data Exchange (ETDEWEB)

Around 2017, the pixel detector of the CMS experiment at LHC will be upgraded. The amount of current that has to be provided to the front-end electronics is expected to increase by a factor of two. Since the space available for cables is limited, this would imply unacceptable power losses in the available supply cables. Therefore it is foreseen to place DC-DC converters close to the front-end electronics, allowing to provide the power at higher voltages and thereby to facilitate the supply of the required currents with the present cable plant. The talk introduces the foreseen powering scheme of the pixel upgrade and summarizes the results of system test measurements with CMS pixel sensor modules, radiation tolerant DC-DC converters and the full power supply chain of the pixel detector. In addition, measurements of the converter efficiency and performance before, after and during thermal cycling are presented.

Feld, Lutz; Karpinski, Waclaw; Klein, Katja; Sammet, Jan; Wlochal, Michael [RWTH Aachen University (Germany)

2012-07-01

282

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

283

Novel Full-bridge ZVS DC-DC Converter with an Clamp Diodes

The two arms of this converter all work at zero-voltage switching condition, that bring many advantages, such as little loss of power, simple control, etc. But these also exists some problems, such as parasitic oscillation on the output rectifier diodes. A novel full-bridge ZVS PWM DC-DC converter which adopts two clamping diodes in the first side of the transformer is proposed to reduce the parasitic oscillation in this paper. In this paper, It heavily analyzes the realization process of their soft-switching and the reason of related issues and solution, we establishes simulation model and simulates using orCAD. Finally,a 5 kW ZVS PWM DC-DC converter Prototype in that TMS320F2812 is the core controlled chip has been set up, and the experiments showed us the validation of the correlative theory.

Guangqun, Nan; Xue, Hu

284

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

285

Simulation and Implementation of Quasi Resonant DC-DC Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 efficie...

Devarajan, N.; Parvathy, P.

2012-01-01

286

Soft switching DC/DC converter using auxiliary circuits

Digital Repository Infrastructure Vision for European Research (DRIVER)

A novel auxiliary circuit for full-bridge PWMDC/DC converter with controlled secondary side rectifieris presented in this paper. Zero-current turn-on for allpower switches of the inverter is achieved for full loadrange from no-load to short circuit by using controlledrectifier and auxiliary circuit on the secondary side.Modified phase shift PWM control strategy is used for theconverter. The principle of operation is explained andanalyzed and the simulation results are presented.

Jaroslav Dudrik; Vladimír Ruš?in

2008-01-01

287

Soft switching DC/DC converter using auxiliary circuits

Directory of Open Access Journals (Sweden)

Full Text Available A novel auxiliary circuit for full-bridge PWMDC/DC converter with controlled secondary side rectifieris presented in this paper. Zero-current turn-on for allpower switches of the inverter is achieved for full loadrange from no-load to short circuit by using controlledrectifier and auxiliary circuit on the secondary side.Modified phase shift PWM control strategy is used for theconverter. The principle of operation is explained andanalyzed and the simulation results are presented.

Jaroslav Dudrik

2008-05-01

288

High-Frequency Soft-Switching DC-DC Converters for Voltage and Current DC Power Sources

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper presents soft switching PWM DC-DC converters using powerMOSFETs and IGBTs. The attention is focused mainly on the full-bridge converterssuitable for high power applications. The properties of the PWM converters are describedin comparison to other categories of soft switching converters. An overview of theswitching techniques using in the DC-DC converters is included. Considerations are alsogiven to the control methods. The principles of the switching and conduction lossesreduction i...

Jaroslav Dudrik; Juraj Oetter

2007-01-01

289

A DC-DC Converter Efficiency Model for System Level Analysis in Ultra Low Power Applications

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a model of inductor based DC-DC converters that can be used to study the impact of power management techniques such as dynamic voltage and frequency scaling (DVFS. System level power models of low power systems on chip (SoCs and power management strategies cannot be correctly established without accounting for the associated overhead related to the DC-DC converters that provide regulated power to the system. The proposed model accurately predicts the efficiency of inductor based DC-DC converters with varying topologies and control schemes across a range of output voltage and current loads. It also accounts for the energy and timing overhead associated with the change in the operating condition of the regulator. Since modern SoCs employ power management techniques that vary the voltage and current loads seen by the converter, accurate modeling of the impact on the converter efficiency becomes critical. We use this model to compute the overall cost of two power distribution strategies for a SoC with multiple voltage islands. The proposed model helps us to obtain the energy benefits of a power management technique and can also be used as a basis for comparison between power management techniques or as a tool for design space exploration early in a SoC design cycle.

Benton H. Calhoun

2013-06-01

290

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

291

A Robust Approach to Controller Design for DC-DC Quasi-Resonant Converters

DC-DC quasi-resonant converters (QRCs) have a highly nonlinear and time-varying behavior as well as other types of DC-DC resonant converters such as conventional and multi-resonant converters. Changing in operating conditions, mainly due to variation in load and line disturbance, leads to significant changes on system dynamics so that desired performance and even stability are lost. Taking into consideration the uprising need for high-quality resonant power converters has opened a new research window on the control of these systems using modern and systematic approaches. In this paper in order to achieve both stability and desired performance, such as reduced sensitivity to load variations, desired disturbance rejection, reduced output impedance and attenuated transfer from input to output, we have proposed a methodology based on ?-synthesis technique for DC-DC QRCs controller design. The ?-analysis is used to verify the robustness of the designed controller. The proposed control strategy is applied to a typical zero-current switching QRC and nonlinear simulation is performed using nonlinear model of converter circuit. The simulation results demonstrate the good reference voltage tracking, line disturbance rejection and show that the designed procedure guarantees the robust stability and robust performance for a wide range of load variation.

Bevrani, Hassan; Ise, Toshifumi; Mitani, Yasunori; Tsuji, Kiichiro

292

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

293

Novel Zero-Current-Transition PWM DC/DC Converters

Energy Technology Data Exchange (ETDEWEB)

In this paper, a novel Zero-Current-Transition (ZCT) technique, which provides Zero-Current-Switching (ZCS) turn-off of the main switch, thr main diode and the auxiliary switch, is presented. The proposed auxiliary circuit consists of minimum elements only one auxiliary switch, resonant inductor and resonant capacitor. Also the reduced di/dt, which is obtained by resonant inductor, helps soft turn-on of the main switch. Besides, to eliminate the additional the conduction loss and current stress on main switch, a topological variation was a performed. The theoretical analysis and the operation principle of the new ZCT techniques are described in detail with a boost converter as an example. To verify thr validity of the proposed ZCT techniques, the simulation and the experiment were performed under lkW output power and 100kHz switching frequency. (author). 10 refs., 13 figs., 1 tab.

Lee, Min Kwang; Lee, Dong Yun; Hyun, Dong Seok [Hanyang University, Seoul (Korea)

2001-02-01

294

Very High Frequency Resonant DC/DC Converters for LED Lighting

DEFF Research Database (Denmark)

This paper presents a very high frequency DC/DC converter for LED lighting. Several resonant topologies are compared and their usability discussed. At the end the resonant SEPIC converter is chosen based on the achievable power density and total bill of material. Simulations of a 51 MHz converter with 40 V input and 15 V output are made. The simulation shows possibility of achieving efficiency up to 87 % even with a HEXFET Power MOSFET. Three prototypes of the simulated converter are implemented showing good correlation with simulations. The prototypes have efficiencies up to 84 % and power densities up to 8.9 W/cm3 (146 W/in3).

Madsen, Mickey Pierre; Knott, Arnold

2013-01-01

295

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

296

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

297

A High Power Density DC-DC Converter for Distributed PV Architectures

Energy Technology Data Exchange (ETDEWEB)

In order to maximize solar energy harvesting capabilities, power converters have to be designed for high efficiency and good MPPT and voltage/current performance. When many converters are used in distributed systems, power density also becomes an important factor as it allows for simpler system integration. In this paper a high power density string dc-dc converter suitable for distributed medium to large scale PV installation is presented. A simple partial power processing topology, implemented with all silicon carbide devices provides high efficiency as well as high power density. A 3.5kW, 100kHz converter is designed and tested to verify the proposed methods.

Agamy, Mohammed S; Chi, Song; Elasser, Ahmed; Harfman-Todorovic, Maja; Jiang, Yan; Mueller, Frank; Tao, Fengfeng

2012-06-01

298

A Nonlinear Digital Control Solution for a DC/DC Power Converter

A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.

Zhu, Minshao

2002-01-01

299

Switched capacitor DC-DC converter ASICs for the upgraded LHC trackers

International Nuclear Information System (INIS)

The High Luminosity Upgrade of the ATLAS Inner Tracker puts demanding requirements on the powering system of the silicon strip detector modules due to 10-fold increase of the channel count compared to the existing SemiConductor Tracker. Therefore, new solutions for the powering scheme must be elaborated. Currently two possible approaches, the serial powering and the parallel powering scheme using the DC-DC conversion technique, are under development. This paper describes two switched capacitor DC-DC converters designed in a 130 nm technology. For the optimized step-down converter, foreseen for the parallel powering scheme, power efficiency of 97% has been achieved, while for the charge pump, designed for the serial powering scheme, power efficiency of 85% has been achieved.

300

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

301

Switched capacitor DC-DC converter ASICs for the upgraded LHC trackers

The High Luminosity Upgrade of the ATLAS Inner Tracker puts demanding requirements on the powering system of the silicon strip detector modules due to 10-fold increase of the channel count compared to the existing SemiConductor Tracker. Therefore, new solutions for the powering scheme must be elaborated. Currently two possible approaches, the serial powering and the parallel powering scheme using the DC-DC conversion technique, are under development. This paper describes two switched capacitor DC-DC converters designed in a 130 nm technology. For the optimized step-down converter, foreseen for the parallel powering scheme, power efficiency of 97% has been achieved, while for the charge pump, designed for the serial powering scheme, power efficiency of 85% has been achieved

Bochenek, M; Faccio, F; Michelis, S; 10.1088/1748-0221/5/12/C12031

2010-01-01

302

Space power supply manufacturers have tried to increase power density and construct smaller, highly efficient power supplies by increasing switching frequency. Incorporation of a power MOSFET as a switching element alleviates switching loss. However, values of R sub DS(on) (drain-to-source resistance in the on-state) for MOSFET's are of such magnitude to produce greater on-state losses than an equivalent BJT operated in saturation. This research serves to introduce a design concept, pertinent to low-voltage relatively-high-current applications, that minimizes the peak current through the switching element in order to reduce average power loss. Basic waveforms produced by different PWM and resonant mode topologies were examined. Theoretical analysis reveals that a ramp-sine current waveform could cut conduction power loss by at least 18 percent over a conventional Buck switching converter. A 14V, 14W combination quasi-resonant Buck/ZCS, Quasi-Resonant Buck dc-dc converter with an unregulated input voltage of 28 V was built for simplicity to demonstrate one particular waveshaping technique. This converter represents a useful example of an actual circuit which is capable of producing the desired ramp-sine switch-current waveform. Final results confirm improvement in conduction loss enhancing existing power MOSFET technology for use in dc-dc power conversion.

Miller, Douglas P.

1990-06-01

303

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

304

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 oper...

Andersen, Toke Meyer; Christensen, Søren K.; Knott, Arnold; Andersen, Michael A. E.

2011-01-01

305

An adaptive digital controller for satellite medium power DC/DC converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper the work concerning an adaptive digital controller for satellite medium power DC/DC converters is presented. The adaptive techniques and methods developed in Space Research Centre allows an implemented in VHDL controller to modify its parameters according to detected changes in operating conditions. Inductor entering from discontinuous to continuous current mode and vice versa or moving sampling instants due to changes in duty time are good examples of varying operation...

Skup, Konrad R.; Grudzi Ski, Pawe; Orlea Ski, Orlea Ski

2011-01-01

306

Inductor based switching DC-DC converter for low voltage power distribution in SLHC

In view of a power distribution scheme compatible with the requirements of the SLHC environment, we are evaluating the feasibility of on-board inductor-based DC-DC step-down conversion. Such converter should be an integrated circuit and capable of operating in harsh radiation environments and in the high magnetic field of the experiments. In this paper we present results concerning the choice of the technology, the search for the magnetic components and the calculations of the expected efficiency.

Michelis, S; Marchioro, A; Kayal, M; PH-EP

2007-01-01

307

Resonant Boost Dc-Dc Converter for a High Frequency Operation

Digital Repository Infrastructure Vision for European Research (DRIVER)

With different versions of inverters available, a control of VHF resonant boost dc-dc converter is described in detailed in this paper. Though, a classical Class- ? inverter is well documented in the literature, this is a new version and coupled to resonant rectifier. The twin aspect of any design of resonant boost topology is to mainly feature low device voltage stress and to have high efficiency over wide range of loads. Increased switching frequency allows smaller size of the passive comp...

Tejaswini R,

2013-01-01

308

A Family of Auxiliary Switch ZVS-PWM DC-DC Converters with Coupled Inductor

Digital Repository Infrastructure Vision for European Research (DRIVER)

A novel auxiliary switch DC-DC converter with coupled inductor is presented in this paper. The proposed circuit achieves loss-less switching for both the main and auxiliary switches without increasing the main device current/voltage rating. A tapping in the pole inductor is added for the purpose of commutation. The proposed circuit is capable of operation at elevated switching frequencies of several hundreds of KHz, high and low power levels with wide range of load variations. In the sections...

Lakshminarasamma, N.; Ramanarayanan, V.

2006-01-01

309

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

310

Dynamic Modelling & Controller Design for Z-Source DC-DC Converter

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the detailed mathematical modeling of Z-source dc-dc converter (ZSC in continuous conduction mode. Transfer function of ZSC is derived based on mathematical modeling with state space averaging method. This paper has been focused on dynamic modeling of open loop transfer function of ZSC along with design of closed loop controller. MATLAB based simulation results are presented for open loop and close loop system of ZSC.

Shilpa Sarode1 S.G. Kadwane2

2013-04-01

311

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

312

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

313

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

314

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

315

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

316

Design & Implementation of Zero Voltage Switching Buck Converter

Directory of Open Access Journals (Sweden)

Full Text Available 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 configuration. This type of soft switched resonant converter offers very low electromagnetic interference (EMI.This study presents the circuit configuration with least components to realize highly efficient zero voltage switching resonant converter. It’s feasibility is confirmed with the developed proto type model and experimental results are verified.

A.Suresh Kumar

2014-09-01

317

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

318

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

319

SOFT-SWITCHED HIGH STEP-UP DC-DC CONVERTER WITH HIGH VOLTAGE GAIN

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a new design of soft switched high step-up dc-dc converter with high voltage gain which is suitable for high power applications such as Uninterruptible Power System (UPS, Photo Voltaic system and hybrid electric vehicles. The emergence of this front-end converter is to improve the shape of active input current given to the system. This converter proposes Soft-Switching technique to achieve ZVS turn on of active switches and ZCS turn off of diodes using Lr - Cr resonance in the auxiliary circuit. Therefore reduces the switching losses. Comparatively the voltage conversion ratio of this converter is higher when compared with the ordinary boost converter. Hence the voltage gain of this converter is also higher. A simulation platform is created using MATLAB which illustrates the ZVS and ZCS operation of the switches and diodes. Open loop and closed loop controlled converter systems are modelled and simulated.

J.C. PAUL IMMANUEL

2013-04-01

320

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tuning PID controller parameters using Evolutionary algorithm for an asynchronous Buck converter is presented in this paper. PID controller is one of the solutions for controlling a Buck converter during transient conditions. There are straight forward ways for calculating the parameters for the PID controller in the literature and evolutionary algorithm based approach with a proper fitnessfunction gives superior performance when compared to other methods. Ziegler Nicholas method, Hurwitz pol...

Augustilindiya, S.; Palani, S.; Vijayarekha, K.; Breethiyeltsina, M.

2013-01-01

321

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

322

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

323

Transistor Selection and Design of a VHF DC-DC Power Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper explores the design and performance of dc-dc power converters operating in the very high frequency (VHF, 30-300 MHz) range. Methods are presented for assessment and comparison of device losses in VHF operation under soft switching and soft gating conditions. These methods are applied to the development of a 2 W resonant boost converter operating at a switching frequency of 30 MHz. Design of the power stage, resonant gate drive, and control circuitry are treated in detail, and exper...

Warren, James R.; Rosowski, Kathryn Anne; Perreault, David J.

2007-01-01

324

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

325

Multi-Level DC-DC Converter for High Gain Applications

Directory of Open Access Journals (Sweden)

Full Text Available The output voltage from most renewable energy sources like photovoltaic arrays and fuel cells will be at low level. This must be stepped up considerably for practical utilization or grid connection. The presented multilevel boost converter DC-DC converter topology consists of the conventional boost converter and voltage doubler stages to provide high voltage gain. The proposed topology uses only one switch along with one inductor, (2N-1 diodes and (2N-1 capacitors for obtaining an output which is N times the conventional boost converter. In this topology, each device blocks only one voltage level. The main advantages of this topology are continuous input current, large gain without high duty cycle or transformer, modularity and use of devices with low voltage ratings. Experimental results obtained from the 100W prototype demonstrate the voltage gain capability of the converter and validates the converter design.

Girish Ganesan R

2013-12-01

326

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

327

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

328

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

329

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

330

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

331

Half bridge ZVS DC-DC converter with DCS PWM active clamp technique

Directory of Open Access Journals (Sweden)

Full Text Available

Half bridge (HB dc–dc converter is an attractive topology for middle power level applications owing to its simplicity. This paper presents 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 one of the two 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, an active clamp branch comprising an auxiliary switch and a diode is added across the isolation transformer primary winding in the half bridge converter to achieve ZVS for the other main switch by utilizing energy stored in the transformer leakage inductance. Moreover, the auxiliary switch also operates at ZVS and ZCS conditions. In addition, the proposed topology with DCS PWM control eliminates the ringing resulting from the oscillation between the transformer leakage inductance and the switches junction capacitances during the off-time period. Therefore, the proposed converter has a potential to operate at higher efficiencies and switching frequencies.

JANAPATI SIVAVARA PRASAD

2012-10-01

332

High-Frequency Soft-Switching DC-DC Converters for Voltage and Current DC Power Sources

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents soft switching PWM DC-DC converters using powerMOSFETs and IGBTs. The attention is focused mainly on the full-bridge converterssuitable for high power applications. The properties of the PWM converters are describedin comparison to other categories of soft switching converters. An overview of theswitching techniques using in the DC-DC converters is included. Considerations are alsogiven to the control methods. The principles of the switching and conduction lossesreduction in the PWM converters are illustrated. Various types of snubber circuits arementioned and their operation and limitations are discussed.

Jaroslav Dudrik

2007-08-01

333

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Ali, Tagreed M.; Jassim, Bassim M. H.

2010-01-01

334

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

335

A new current-fed, isolated PWM dc-dc converter

Energy Technology Data Exchange (ETDEWEB)

This paper introduces a new current-fed dc-dc power converter circuit whose features are as follows: two active switches gated in a complementary and asymmetrical way, connected to the same ground; inherent high reliability provided by the input boost inductor; isolation by a high-frequency transformer; and output filter purely capacitive. Circuit operation, theoretical analysis, and design procedure are presented. Experimental results taken from a prototype, rated at 48 V/300 W, are also included in the paper to demonstrate the validity of the theoretical analysis.

Mantovanelli, P.; Barbi, I. [Federal Univ. of Santa Catarina, Florianopolis, Santa Catarina (Brazil)

1996-05-01

336

Fuzzy control of the DC-DC converter used as power interface for a fuel cell

International Nuclear Information System (INIS)

In this paper it is analyzed a feed-forward fuzzy control for PWM control of the DC-DC converter using a fuel cell as energy source. For a dynamic load the fuel cell output voltage vary in large DC range and the high DC voltage stabilization can not be a difficult task. The advantages of the forward loop after the fuel cell output voltage concerning the stability and robustness of fuzzy control are compared with the best results obtained using a well designed proportional-integral control. The Simulink models for the used blocks, simulation results, and some design consideration are presented, too. (authors)

337

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

338

A Novel Soft Switching Full-Bridge PWM DC/DC Converter with Secondary Clamping Circuit

Energy Technology Data Exchange (ETDEWEB)

This paper proposes a novel secondary clamping circuit for soft switching full-bridge PWM DC/DC converter. The proposed clamping circuit eliminates the reflecting current of the secondary side of the transformer so that reduce the conduction loss of the primary side of it during the freewheeling mode. Also, it ensures the zero-voltage/zero-current switching of the leading/lagging switches. The characteristics of the proposed clamping circuit are investigated and the validity is verified by the experimental results. (author). refs., figs.

Choo, Byeong Ho [Samsung Electronics Corporate Technical Operations (Korea, Republic of); Lee, Byoung Kuk; Yoo, Sang Bong; Hyun, Dong Seok [Hanyang University (Korea, Republic of)

1998-06-01

339

A Novel Secondary Clamping Circuit for Soft Switching Full-Bridge PWM DC/DC Converter

Energy Technology Data Exchange (ETDEWEB)

This paper proposes a novel secondary clamping circuit for soft switching full-bridge PWM DC/DC converter. The proposed clamping circuit eliminates the reflecting current of the secondary side of the transformer so that reduce the conduction loss of the primary side of it during the freewheeling mode. Also, it ensures the zero-voltage/zero-current switching of the leading and the legging switches. The characteristics of the proposed clamping circuit are investigated and the validity is verified by the simulation results. (author). refs., figs.

Choo, B.H.; Lee, B.K.; Yoo, S.B.; Hyun, D.S. [Hanyang University (Korea, Republic of)

1997-04-01

340

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

341

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

342

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

343

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; Knott, Arnold

2011-01-01

344

Low Temperature Performance of High Power Density DC/DC Converter Modules

In this paper, two second-generation high power density DC/DC converter modules have been evaluated at low operating temperatures. The power rating of one converter (Module 1) was specified at 150 W with an input voltage range of 36 to 75 V and output voltage of 12 V. The other converter (Module 2) was specified at 100 W with the same input voltage range and an output voltage of 3.3 V. The converter modules were evaluated in terms of their performance as a function of operating temperature in the range of 25 to -140 C. The experimental procedures along with the experimental data obtained are presented and discussed in this paper.

Elbuluk, Malik E.; Hammond, Ahmad; Gerber, Scott; Patterson, Richard L.; Overton, Eric

2001-01-01

345

Performance of a spacecraft DC-DC converter breadboard modified for low temperature operation

A 1OW 3OV/5.OV push-pull dc-dc converter breadboard, designed by the Jet Propulsion Laboratory (JPL) with a +50 C to +5 C operating range for the Cassini space probe, was characterized for lower operating temperatures. The breadboard converter which failed to operate for temperatures below -125 C was then modified to operate at temperatures approaching that of liquid nitrogen (LN2). Associated with this low operating temperature range (greater than -196 C) was a variety of performance problems such as significant change in output voltage, converter switching instability, and failure to restart at temperatures below -154 C. An investigation into these problems yielded additional modifications to the converter which improved low temperature performance even further.

Gerber, Scott S.; Stell, Chris; Patterson, Richard; Ray, Biswajit

1996-01-01

346

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

347

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

348

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

349

Comparison of MPPT Algorithms for DC-DC Converters Based PV Systems

Digital Repository Infrastructure Vision for European Research (DRIVER)

The comparative study between two most popular algorithms technique which is incremental conductance algorithm and perturbs and observe algorithm. Two different converters buck and boost converter use for comparative in this study. Few comparison such as voltage, current and power output for each different combination has been recorded.MATLAB Simulink tools have been used for performance evaluation on energy point.

Pradeep Kumar Yadav, A.; Thirumaliah, S.; Haritha, G.

2013-01-01

350

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

351

Directory of Open Access Journals (Sweden)

Full Text Available A novel asymmetrical interleaved dc/dc switching converters family intended for photovoltaic and fuel cell applications is presented in this paper. The main requirements on such applications are small ripples in the generator and load, as well as high voltage conversion ratio. Therefore, interleaved structures and voltage multiplier cells have been asymmetrically combined to generate new converters, which inherently operate indiscontinuous conduction mode. The novel family is derived from boost, buck-boost and flyback-based structures. This converter family is analyzed to obtain the design equations and synthesize a design process based on the typical requirements of photovoltaic and fuel cell applications. Finally, the experimental results validate the characteristics and usefulness of the asymmetrical interleaved converter family.

Sergio Serna

2012-11-01

352

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 convert...

Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.

2007-01-01

353

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

Energy Technology Data Exchange (ETDEWEB)

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 {mu}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)

Liu Zhi; Yu Hongbo; Liu Youbao [Xi' an Institute of Microelectronics Technology, Xi' an 710054 (China); Ning Hongying, E-mail: liuzhi6048@126.com [Xi' an University of Technology, Xi' an 710048 (China)

2011-07-15

354

A Compact, Soft-Switching DC-DC Converter for Electric Propulsion

A hybrid, soft-switching, DC-DC converter has been developed with superior soft switching characteristics, high efficiency, and low electro-magnetic interference. This hybrid topology is comprised of an uncontrolled bridge operating at full pulse-width, and a controlled section operating as a conventional phase modulated converter. The unique topology is able to maintain zero voltage switching down to no load operating conditions. A breadboard prototype was developed and tested to demonstrate the benefits of the topology. Improvements were then made to reduce the size of passive components and increase efficiency in preparation for packaging. A packaged prototype was then designed and built, and several innovative packaging techniques are presented. Performance test data is presented that reveals deficiencies in the design of the power transformer. A simple redesign of the transformer windings eliminated the deficiency. Future plans to improve the converter and packaging design are presented along with several conclusions.

Button, Robert; Redilla, Jack; Ayyanar, Raja

2003-01-01

355

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)

356

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

357

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

358

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

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.

Zhi, Liu; Hongying, Ning; Hongbo, Yu; Youbao, Liu

2011-07-01

359

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

360

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 converter is first described, and then, the design equation is derived. A 1.5-kW prototype with low-side voltage of 48 V and high-side voltage of 360 V has been implemented, from which experimental results have verified its feasibility.

Chitanya

2013-05-01

361

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

362

Static and Dynamic Characteristics of DC-DC Converter Using a Digital Filter

This paper presents the regulation and dynamic characteristics of the dc-dc converter with digital PID control, the minimum phase FIR filter or the IIR filter, and then the design criterion to improve the dynamic characteristics is discussed. As a result, it is clarified that the DC-DC converter using the IIR filter method has superior performance characteristics. The regulation range is within 1.3%, the undershoot against the step change of the load is less than 2% and the transient time is less than 0.4ms with the IIR filter method. In this case, the switching frequency is 100kHz and the step change of the load R is from 50 ? to 10 ?. Further, the superior characteristics are obtained when the first gain, the second gain and the second cut-off frequency are relatively large, and the first cut-off frequency and the passing frequency are relatively low. Moreover, it is important that the gain strongly decreases at the second cut-off frequency because the upper band pass frequency range must be always less than half of the sampling frequency based on the sampling theory.

Kurokawa, Fujio; Okamatsu, Masashi

363

A DC-DC converter based powering scheme for the upgrade of the CMS pixel detector

International Nuclear Information System (INIS)

Around 2016, the pixel detector of the CMS experiment will be upgraded. The amount of current that has to be provided to the front-end electronics is expected to increase by a factor of two. Since the space available for cables is limited, this would imply unacceptable power losses in the currently installed supply cables. Therefore it is foreseen to place DC-DC converters close to the front-end electronics, allowing the provision of power at higher voltages, thereby facilitating the supply of the required currents with the present cable plant. This conference report introduces the foreseen powering scheme of the pixel upgrade. For the first time, system tests have been conducted with pixel barrel sensor modules, radiation tolerant DC-DC converters and the full power supply chain of the pixel detector. In addition, studies of the stability of different powering schemes under various conditions are summarized. In particular the impact of large and fast load variations, which are related to the bunch structure of the LHC beam, has been studied.

364

A DC-DC converter based powering scheme for the upgrade of the CMS pixel detector

Around 2016, the pixel detector of the CMS experiment will be upgraded. The amount of current that has to be provided to the front-end electronics is expected to increase by a factor of two. Since the space available for cables is limited, this would imply unacceptable power losses in the currently installed supply cables. Therefore it is foreseen to place DC-DC converters close to the front-end electronics, allowing the provision of power at higher voltages, thereby facilitating the supply of the required currents with the present cable plant. This conference report introduces the foreseen powering scheme of the pixel upgrade. For the first time, system tests have been conducted with pixel barrel sensor modules, radiation tolerant DC-DC converters and the full power supply chain of the pixel detector. In addition, studies of the stability of different powering schemes under various conditions are summarized. In particular the impact of large and fast load variations, which are related to the bunch structure of the LHC beam, has been studied.

Feld, L.; Karpinski, W.; Klein, K.; Merz, J.; Sammet, J.; Wlochal, M.

2011-11-01

365

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.

366

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

367

A Stable Control Strategy for Input-Series Output-Series Connected Boost half Bridge DC-DC Converter

Directory of Open Access Journals (Sweden)

Full Text Available Boost half bridge DC-DC converters in the combination of an input-series and output-series (ISOS connected configuration with a stable control strategy has been investigated in this paper. A stable control strategy comprises of two loops that are current loop and voltage loop. The reference to the current loop has been chosen from the input side of the DC-DC converter. The reference to the voltage loop has been selected from the output side of the DC-DC converter. Such a reference makes the circuit configuration simple, easy and eventually results in reduced cost. The control strategy for input-series output-series (ISOS configuration of DC-DC converters is proposed to achieve equal input voltage sharing (IVS as well output voltage sharing (OVS. Furthermore, in this paper, the performance of the stable control strategy for input-series output-series (ISOS boost half bridge DC-DC converter has been observed not only for the fixed but also for the varying and continuously varying load. The proposed Stable control scheme has been developed by modeling it on MATLAB using Simulink and Simpower toolboxes. The operation of the proposed stable control strategy has been found to be satisfactory.

Shahnawaz Farhan Khahro

2013-07-01

368

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

369

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

370

ASIC and FPGA based DPWM architectures for single-phase and single-output DC-DC converter: a review

Pulse width modulation (PWM) has been widely used in power converter control. This paper presents a review of architectures of the Digital Pulse Width Modulators (DPWM) targeting digital control of switching DC-DC converters. An attempt is made to review the reported architectures with emphasis on the ASIC and FPGA implementations in single phase and single-output DC-DC converters. Recent architectures using FPGA's advanced resources for achieving the resolution higher than classical methods have also been discussed. The merits and demerits of different architectures, and their relative comparative performance, are also presented. The Authors intention is to uncover the groundwork and the related references through this review for the benefit of readers and researchers targeting different DPWM architectures for the DC-DC converters.

Chander, Subhash; Agarwal, Pramod; Gupta, Indra

2013-12-01

371

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

372

High-Voltage 1-kW dc/dc Converter Developed for Low-Temperature Operation

Recently, Lewis developed and demonstrated a high-voltage, 1-kW dc/dc converter that operates from room temperature to -184 C. A power supply designed for use in a NASA ion beam propulsion system was utilized as a starting point for the design of a low- (wide-) temperature dc/dc converter. For safety, we decided to halve the output voltage and power level, so the converter was designed for an 80-Vdc input and a 550-Vdc output at 1 kW.

Patterson, Richard L.

1998-01-01

373

Design and Simulation of a soft switching scheme for a dc-dc Boost Converter with pi controller

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the design of simple but powerful soft switching scheme for a DC-DC Boost Converter with a closed loop control. A new novel soft switching scheme is proposed with a single switch and minimum components which offers load independent operations. The only switch used in this converter is switched ON at zero current and switched OFF at zero voltage .The proposed Controller is used to improve the dynamic performance of DC-DC converter by achieving a robust output voltage agains...

Felix Joseph, X.; Pushpa Kumar, S.; Arun Dominic, D.; Mary Synthia Regis Prabha, D. M.

2010-01-01

374

Non-Inverting Buck-Boost Converter for Fuel Cell Applications

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

375

DC-DC converters in 0.35?m CMOS technology

International Nuclear Information System (INIS)

In view of the upgrade of the LHC experiments, we are developing custom DC/DC converters for a more efficient power distribution scheme. A new prototype have been integrated in ASICs in the selected 0.35?m commercial high voltage technology that has been successfully tested for all radiation effects: TID, displacement damage and Single Event Burnout. This converter has been optimized for high efficiency and improved radiation tolerance. Amongst the new features the most relevant are the presence of internal linear regulators, protection circuits with a state-machine and a new pinout for a modified assembly in package in order to reduce conductive losses. This paper illustrates the design of the prototype followed by functional and radiation tests.

376

SSP Technology Investigation of a High-Voltage DC-DC Converter

The goal of this project was to establish the feasibility of a high-voltage DC-DC converter based on a rod-array triggered vacuum switch (RATVS) for the Space Solar Power system. The RATVS has many advantages over silicon and silicon-carbide devices. The RATVS is attractive for this application because it is a high-voltage device that has already been demonstrated at currents in excess of the requirement for an SSP device and at much higher per-device voltages than existing or near-term solid state switching devices. The RATVS packs a much higher specific power rating than any solid-state device and it is likely to be more tolerant of its surroundings in space. In addition, pursuit of an RATVS-based system would provide NASA with a nearer-term and less expensive power converter option for the SSP.

Pappas, J. A.; Grady, W. M.; George, Patrick J. (Technical Monitor)

2002-01-01

377

Adaptive Non-singular Terminal Sliding Mode Control for DC-DC Converters

Directory of Open Access Journals (Sweden)

Full Text Available DC-DC converters have some inherent characteristics such as high nonlinearity and time-variation, which often result in some difficulties in designing control schemes. An adaptive non-singular terminal sliding mode control method is presented in this paper. Non-singular terminal sliding mode control is used to make the converter reach steady state within a limited time, and an adaptive law is integrated to the non-singular terminal sliding mode control scheme to make the proposed control method have adaptive ability to disturbances, and overcome the limitation on non-singular terminal sliding mode control scheme caused by disturbance boundary value. Simulation results show the validity of this adaptive non-singular terminal sliding mode control approach.

YU, Y.

2011-05-01

378

Conventional control and fuzzy control of a dc-dc converter for machine drive

Energy Technology Data Exchange (ETDEWEB)

Fuzzy logic or fuzzy set theory is recently getting increasing emphasis in process control applications. The paper describes an application of fuzzy logic in speed control system that uses a dc-dc converter. The fuzzy control is used to linearize the family of external characteristics of the converter in discontinuous-conduction mode occurring at light load and/or high speed. In order to compare the conventional control with the fuzzy logic control, algorithms have been developed in detail and verified by Microsoft Excel simulation. The simulation study indicates that fuzzy control is a good alternative for conventional control methods, being used particularly in non-linear complex systems ill defined or totally unknown. Where the mathematical model exists, it is useful. The applications of fuzzy set theory in power electronics are almost entirely new; fuzzy logic seems to have a lot of premises in the large industrial control field. (orig.) 2 refs.

Radoi, C.; Florescu, A. [Department of Power Electronics `Politecnica` University Bucharest (Romania)

1997-12-31

379

New ZVZCS PWM DC-DC Converters with One Auxiliary Switch

Energy Technology Data Exchange (ETDEWEB)

This paper presents new Zero-Voltage-/Zero-Current-Switching (ZVZCS) PWM DC-DC converters. The proposed soft-switching technique achieves ZVS and ZCS simultaneously at both turn-on and turn-off of the main switch and diode by using only one auxiliary switch. Also, the proposed soft-switching technique is suitable for not only minority but also majority carrier semiconductor devices. The auxiliary circuit of the proposed topology is placed out the main power path and therefore, there are no voltage/current stresses on the main switch and diode. The operating principle of the proposed topology is illustrated by a detailed study with a boost converter as an example. Theoretical analysis, simulation and experimental results are presented to explain the proposed schemes. (author). 10 refs., 9 figs., 1 tab.

Ryu, Seung Hee [LG Electronics Ins (Korea); Lee, Dong Yun; Hyun, Dong Seok [Hanyang University (Korea); Yoo, Sang Bong [Song Dam University (Korea)

2000-03-01

380

DC-DC converters in 0.35?m CMOS technology

In view of the upgrade of the LHC experiments, we are developing custom DC/DC converters for a more efficient power distribution scheme. A new prototype have been integrated in ASICs in the selected 0.35?m commercial high voltage technology that has been successfully tested for all radiation effects: TID, displacement damage and Single Event Burnout. This converter has been optimized for high efficiency and improved radiation tolerance. Amongst the new features the most relevant are the presence of internal linear regulators, protection circuits with a state-machine and a new pinout for a modified assembly in package in order to reduce conductive losses. This paper illustrates the design of the prototype followed by functional and radiation tests.

Michelis, S.; Allongue, B.; Blanchot, G.; Faccio, F.; Fuentes, C.; Orlandi, S.; Saggini, S.; Cengarle, S.; Ongaro, F.

2012-01-01

381

Bifurcation Boundary Conditions for Switching DC-DC Converters Under Constant On-Time Control

Sampled-data analysis and harmonic balance analysis are applied to analyze switching DC-DC converters under constant on-time control. Design-oriented boundary conditions for the period-doubling bifurcation and the saddle-node bifurcation are derived. The required ramp slope to avoid the bifurcations and the assigned pole locations associated with the ramp are also derived. The derived boundary conditions are more general and accurate than those recently obtained. Those recently obtained boundary conditions become special cases under the general modeling approach presented in this paper. Different analyses give different perspectives on the system dynamics and complement each other. Under the sampled-data analysis, the boundary conditions are expressed in terms of signal slopes and the ramp slope. Under the harmonic balance analysis, the boundary conditions are expressed in terms of signal harmonics. The derived boundary conditions are useful for a designer to design a converter to avoid the occurrence of the ...

Fang, Chung-Chieh

2012-01-01

382

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

383

Comparative Study of PI Controlled and Fuzzy Controlled Buck Converter

Directory of Open Access Journals (Sweden)

Full Text Available The main objective of this paper is to compare the performance between fuzzy controller and proportional integral controller in improving the performance of the DC-DC Buck Converter. The evaluation of the output has been carried out and compared by software simulation using MATLAB. This paper also evaluates the stability of the system with fuzzy controller and PI controller and concludes that the fuzzy controller is able to achieve faster transient response, has major stable steady state response and is more robust under different operating points

Neetu Sharma1 , Dr.Pradyumn Chaturvedi2 , Rahul Dubey

2013-03-01

384

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

385

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

386

An analog maximum power point tracking (MPPT) circuit for a thermoelectric generator (TEG) is proposed. We show that the peak point of the voltage conversion gain of a boost DC-DC converter with an input voltage source having an internal resistor is the maximum power point of the TEG. The key characteristic of the proposed MPPT controller is that the duty ratio of the input clock pulse to the boost DC-DC converter shifts toward the maximum power point of the TEG by seeking the peak gain point of the boost DC-DC converters. The proposed MPPT technique provides a simple and useful analog MPPT solution, without employing digital microcontroller units.

Park, Jungyong; Kim, Shiho

2012-06-01

387

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

388

A 10 kW dc-dc converter using IGBTs with active snubbers. [Insulated Gate Bipolar Transistor

This full bridge dc-dc converter employs zero voltage switching (ZVS) on one leg and zero current switching (ZCS) on the other. This technique produces exceptionally low IGBT switching losses through the use of an active snubber that recycles energy back to the source. Experimental results are presented for a 10 kW, 20 kHz converter.

Masserant, Brian J.; Shriver, Jeffrey L.; Stuart, Thomas A.

1993-01-01

389

A state-space modeling of non-ideal dc-dc converters

A model based on practical switches with finite turn-on, turn-off, delay, storage, and reverse recovery times is proposed. The effects of switching on the state equation, system stability, dc gain, and efficiency are shown for boost, buck, and buck-boost converters. The effect of current-based switching-time variation on system stability is given as an extension of the storage-time modulation effect, and the effect of average-duty-cycle variation on system stability is considered. The dc gains of boost and buck-boost converters are shown to be greatly degraded by switching loss. It is also shown that no additional resistance is generated by switching, in contradiction to previous work. It is found that the buck converter is superior to the others from the viewpoints of system stability and dc gain, and that the efficiencies of all the converters are maximized when the dc gain is close to unity. Previous results are improved and unified using state-space modeling. Analysis results are very simple in spite of the complex switching waveforms. This modeling approach is believed to be very useful for high-frequency or high-power applications where switching effects become dominant.

Rim, C. T.; Joung, G. B.; Cho, G. H.

390

DC-DC converters for the upgrades of the CMS tracker

International Nuclear Information System (INIS)

Within the present decade, it is foreseen to gradually increase the instantaneous luminosity of the LHC to 1-2.1034 cm-2s-1. Around 2020, it is intended to increase the luminosity further, to about 5.1034 cm-2s-1. To ensure and improve its physics performance, CMS is going to exchange its pixel detector around 2016. Four years later the complete tracker is going to be replaced by a new development. The use of DC-DC converters is foreseen for both of these upgrades. Radiation tolerant converters developed by working groups at CERN and Aachen match the requirements of the new pixel detector already. However, further work is required to integrate the converters on system level and to ensure their save and reliable operation. The status of this work is presented. Building a new tracking detector equipped with converters, raises several additional challenges. In particular the noise performance of the converters and their efficiency at large conversion ratios still has to be improved. The coil, used by the converters to buffer energy, has a significant impact on both of these issues. Effort has been put into the optimization of converter coils, as well as into the exploration and minimization of noise radiated by the coils. The talk gives a summary of the results of this work.

391

Design and Implementation of Coaxial Winding Transformers for Isolated DC-DC Converters

High power isolated DC/DC converters have been extensively used in various applications. Significant research efforts have been devoted to increase the operating efficiency and power density of the converter. Soft switching full bridge converter has been proposed to meet these goals by establishing zero voltage switching condition across the power transistors. However, a significant inductor is required to facilitate the resonance condition, and results in increased loss and reduced power density of the converter. In this article, a full bridge converter with limited soft switching capability (1)-(3) and a coaxially-wound transformer are presented to improve the power density. With the coaxial winding structure, the coupling coefficient the transformer will be much higher than conventional transformer, and result in small leakage inductance. The duty cycle loss of the converter is also reduced thanks to the low leakage inductance of the coaxial transformer. Various coaxial structures are presented in this paper Detailed simulations using Ansoft are conducted to observe their magnetic characteristics. These coaxial transformers are constructed in the laboratory and tested with the full bridge converter under soft-switching conditions to evaluate the performance of the entire system.

Cheng, Po-Tai; Yang, Siang-Yu; Guan, Yeh; Wang, Shinn-Shyong

392

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

393

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

394

A dual VCDL DLL based gate driver for zero-voltage-switching DC-DC converter

International Nuclear Information System (INIS)

This paper presents a dual voltage-controlled-delay-line (VCDL) delay-lock-loop (DLL) based gate driver for a zero-voltage-switching (ZVS) DC-DC converter. Using the delay difference of two VCDLs for the dead time control, the dual VCDL DLL is able to implement ZVS control with high accuracy while keeping good linearity performance of the DLL and low power consumption. The design is implemented in the CSM 2P4M 0.35 ?m CMOS process. The measurement results indicate that an efficiency improvement of 2%-4% is achieved over the load current range from 100 to 600 mA at 4 MHz switching frequency with 3.3 V input and 1.3 V output voltage.

395

A dual VCDL DLL based gate driver for zero-voltage-switching DC-DC converter

This paper presents a dual voltage-controlled-delay-line (VCDL) delay-lock-loop (DLL) based gate driver for a zero-voltage-switching (ZVS) DC-DC converter. Using the delay difference of two VCDLs for the dead time control, the dual VCDL DLL is able to implement ZVS control with high accuracy while keeping good linearity performance of the DLL and low power consumption. The design is implemented in the CSM 2P4M 0.35 ?m CMOS process. The measurement results indicate that an efficiency improvement of 2%-4% is achieved over the load current range from 100 to 600 mA at 4 MHz switching frequency with 3.3 V input and 1.3 V output voltage.

Xin, Tian; Xiangxin, Liu; Wenhong, Li

2010-07-01

396

Resonant Boost Dc-Dc Converter for a High Frequency Operation

Directory of Open Access Journals (Sweden)

Full Text Available With different versions of inverters available, a control of VHF resonant boost dc-dc converter is described in detailed in this paper. Though, a classical Class- ? inverter is well documented in the literature, this is a new version and coupled to resonant rectifier. The twin aspect of any design of resonant boost topology is to mainly feature low device voltage stress and to have high efficiency over wide range of loads. Increased switching frequency allows smaller size of the passive components, allowing one to use air-core magnetic, and thereby reducing core loss. The output is regulated by MPPT controller. The performance analysis was carried out on MATLAB/Simulink platform and performance characteristics are presented along with the values of components.

Tejaswini R,

2013-07-01

397

Bifurcation diagram features of a dc-dc converter under current-mode control

International Nuclear Information System (INIS)

A common tool for analysis of the systems dynamics when the system has chaotic behaviour is the bifurcation diagram. In this paper, the bifurcation diagram of an ideal model of a dc-dc converter under current-mode control is analysed. Algebraic relations that give the critical points locations and describe the pattern of the bifurcation diagram are derived. It is shown that these simple algebraic and geometrical relations are responsible for the complex pattern of the bifurcation diagrams in such circuits. More explanation about the previously observed properties and introduction of some new ones are exposited. In addition, a new three-dimensional bifurcation diagram that can give better imagination of the parameters role is introduced

398

DC-DC switching converter based power distribution vs serial power distribution EMC strategies

This paper presents a detailed and comparative analysis from the electromagnetic compatibility point of view of the proposed power distributions for the SLHC tracker up-grade. The main idea is to identify and quantify the noise sources, noise distribution at the system level and the sensitive areas in the front-end electronics corresponding to both proposed topologies: The DC-DC converter based power distribution and the serial power distribution. These studies will be used to define critical points on both systems to be studied and prototyped to ensure the correct integration of the system taking critically into account the electromagnetic compatibility. This analysis at the system level is crucial to ensure the final performance of the detector using non conventional power distributions, avoiding interference problems and excessive losses that can lead to catastrophic failures or expensive and un-practical solutions.

Arteche, F; Iglesias, M; Rivetta, C; Arcega, F G; Vila, I

2009-01-01

399

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we study on buck dc/dc converter of high efficiency by soft switching technique. The paper will focus on modeling, analysis, and design and simulation buck converter architecture. 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-integral (PI. The effectiveness of the step down converter is verified through simulation results using control oriented simulator like MATLAB/Simulink tools. The circuit operation, designs and simulation results are mentioned in this paper.

Sugandhra Pal Singh

2014-07-01

400

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

401

Analysis of a Multi-Oscillated Current Resonant Type DC-DC Converter

This paper presents the analysis of a new multi-oscillated current resonant type DC-DC converter. Current resonant converters have several remarkable features such as high efficiency, small size, low cost and low noise, and are frequently employed in many portable electronic systems such as personal computers, cellular phones and flat panel displays. The current resonant type converter generally employs pulse frequency modulation for constant voltage control in the output. For this reason, the magnetizing current through the converter not only causes a power loss under a light load, but also a loss during stand-by. Therefore, this type of converter has a problem in that the required smaller size cannot be achieved, because an auxiliary source is necessary for stand-by. In order to solve these problems, a new current resonant type power supply is proposed in which two driving methods are employed. In these driving methods, one MOSFET as a main switch is driven by an auxiliary winding of the transformer and another MOSFET as a main switch is driven by the driving IC with a low withstand voltage. Good agreement of the observed and simulated waveforms was confirmed. In addition, eight distinct states and four distinct operating modes, which compose of the sequence of states, were clarified by experimental and simulated analysis.

Matsuo, Osamu; Matsuo, Hirofumi; Ishizuka, Yoichi; Ota, Hiroyuki

402

High Step up DC-DC Converter with PID Controller for Photovoltaic Applications

Directory of Open Access Journals (Sweden)

Full Text Available From the literature survey, it is observed that the need of ac photovoltaic modules in photovoltaic (PV power-generation market has increased. However, the important aspect is a requirement of a high voltage gain converter for the module’s grid connection through a dc–ac inverter. A high step up dc-dc converter using PI controller is proposed and presented in this paper. Further, the converter proposed in this paper employs a floating active switch, which is designed to isolate the dc current from the PV panel when the ac module is off-grid as well as in the non-operating condition. This isolation will ensure the operation of the internal components without any residential energy being transferred to the output or input terminal,. The PI controller is used in feedback in order to speed-up the response. The converter achieves a high step-up voltage-conversion ratio without extreme duty ratio and the numerous turns-ratios of a coupled inductor. The leakage inductor energy of the coupled inductor is efficiently recycled to the load. The proposed converter model along with PI controller is modeled using SIMULINK and the simulation results are presented in this paper to authenticate the proposed scheme.

Rakesh Kumar Goudanaikar

2014-06-01

403

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

404

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nonlinear systems, such as switching DC-DC boost or buck converters, have rich dynamics. A simple one-dimensional discrete-time model is used to analyze the boost or buck converter in discontinuous conduction mode. Seven different control schemes (open-loop power stage, voltage mode control, current mode control, constant power load, constant current load, constant-on-time control, and boundary conduction mode) are analyzed systematically. The linearized dynamics is obtained...

Fang, Chung-chieh

2012-01-01

405

High efficiency and low electromagnetic interference boost DC-DC converter

A synchronous boost DC-DC converter with an adaptive dead time control (DTC) circuit and anti-ringing circuit is presented. The DTC circuit is used to provide adjustable dead time and zero inductor current detection for power transistors and therefore, a high efficiency is achieved by minimizing power losses, such as the shoot-through current loss, the body diode conduction loss, the charge-sharing loss and the reverse inductor current loss. Simultaneously, a novel anti-ringing circuit controlled by the switching sequence of power transistors is developed to suppress the ringing when the converter enters the discontinuous conduction mode (DCM) for low electromagnetic interference (EMI) and additional power savings. The proposed converter has been fabricated in a 0.6 ?m CDMOS technology. Simulation and experimental results show that the power efficiency of the boost converter is above 81% under different load currents from 10 to 250 mA and a peak efficiency of 90% is achieved at about 100 mA. Moreover, the ringing is easily suppressed by the anti-ringing circuit and therefore the EMI noise is attenuated.

Yajun, Li; Xinquan, Lai; Qiang, Ye; Bing, Yuan

2014-04-01

406

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

407

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

408

Directory of Open Access Journals (Sweden)

Full Text Available This work examines a series resonant DC/DC optimal trajectory controlled converter during operation above resonant frequency, taking into account the influence of the snubbers and matching transformer. We obtain expressions for the load characteristics, boundary curves between possible modes and limits of the soft commutation area. Computer simulation and experimental observation confirm the theoretical results.

Bankov Dimitrov Nikolay

2012-01-01

409

Directory of Open Access Journals (Sweden)

Full Text Available Tuning PID controller parameters using Evolutionary algorithm for an asynchronous Buck converter is presented in this paper. PID controller is one of the solutions for controlling a Buck converter during transient conditions. There are straight forward ways for calculating the parameters for the PID controller in the literature and evolutionary algorithm based approach with a proper fitnessfunction gives superior performance when compared to other methods. Ziegler Nicholas method, Hurwitz polynomial method and Genetic Algorithm based method are compared. It is found that Genetic Algorithm based method yields better result. The hardware implementation of Genetic Algorithm assisted PID controller with low cost is desired and such an implementation is taken in this paper. A low cost microcontroller with built-in PWM modules is implemented and the performance is compared with simulations.

S.Augustilindiya

2013-08-01

410

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

411

Transition from periodicity to chaos in a PWM-controlled buck converter with ZAD strategy

Digital Repository Infrastructure Vision for European Research (DRIVER)

The transition from periodicity to chaos in a DC-DC Buck power converter is studied in this paper. The converter is controlled through a direct Pulse Width Modulation (PWM) in order to regulate the error dynamics at zero. Results show robustness with low output error and a fixed switching frequency. Furthermore, some rich dynamics appear as the constant associated with the first order error dynamics decreases. Finally, a transition from periodicity to chaos is observed. This paper describes t...

Angulo Garci?a, Fabiola; Fossas Colet, Enric; Olivar, Gerard

2005-01-01

412

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

413

The Study of MOSFET Parallelism in High Frequency DC/DC Converter

Digital Repository Infrastructure Vision for European Research (DRIVER)

The study of MOSFET parallelism and the impact on body diode conduction loss of the switch are presented in this paper. The simulation is carried out for synchronous rectifier buck converter (SRBC) in continuous conduction mode where several configurations of the MOSFET connected in parallel are applied. It is found that the body diode conduction loss has been reduced of more than 35 % in fourparallel S1 with one S2 compared to the single pair totempoled switched SRBC circuit.

Yahaya, N. Z.; Makhtar, N. A.

2012-01-01

414

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

415

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

416

A Protection Circuit for DC-DC Converter with Voltage Doubler

Directory of Open Access Journals (Sweden)

Full Text Available 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 used in place of ordinary air core transformer, which is small in size with number of turns of the transformer is reduced and the overall power density is increased. The doubler circuit consists of electrolytic capacitors, which are rated at 400V in order to comply with IEC65 requirements. This paper proposes an “electrolytic capacitor protection circuit”, which enables the voltage rating of the electrolytics to be reduced to 250V. This circuit results in cost savings of more than 50% in the price of the electrolytic filter capacitors. The circuits were simulated using PSPICE SOFTWARE and the following results were obtained. For an input voltage of 200V, an output of 200V and400V were obtained in bridge mode and doubler mode respectively.

D.Elangovan

2012-12-01

417

Basic circuits to design switched-based DC-DC converters

Directory of Open Access Journals (Sweden)

Full Text Available 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 componentsEl 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 cuenta 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

F Sandoval-Ibarra

2007-12-01

418

Design and Simulation of a soft switching scheme for a dc-dc Boost Converter with pi controller

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the design of simple but powerful soft switching scheme for a DC-DC Boost Converter with a closed loop control. A new novel soft switching scheme is proposed with a single switch and minimum components which offers load independent operations. The only switch used in this converter is switched ON at zero current and switched OFF at zero voltage .The proposed Controller is used to improve the dynamic performance of DC-DC converter by achieving a robust output voltage against load disturbances. The duty cycle of the Boost converter is controlled by PI Controller. A 50W/50KHz soft switched PWM Boost converter is simulated and analyzed. The results are simulated using PSIM

X.Felix Joseph

2010-10-01

419

Design of current source DC/DC converter and inverter for 2kW fuel cell application

DEFF Research Database (Denmark)

In order to use hydrogen fuel cell in domestic applications either as main power supply or backup power source, the low DC output voltage of the fuel cell has to be matched to the voltage level and frequency of the utility grid AC voltage. The interfacing power converter systems usually consist of a DC/DC converter and an inverter. In this paper a detailed simulation study of such interfacing converter system comprising a double inductor push-pull step-up DC/DC converter and a cascaded H-bridge inverter has been carried out and further confirmed with experimental results. The power converter system is designed for interfacing a 2kW proton exchange membrane (PEM) fuel cell.

Andreiciks, A.; Steiks, I.

2013-01-01

420

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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

421

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

422

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

423

Dynamic analysis of the input-controlled buck converter fed by a photovoltaic array

Directory of Open Access Journals (Sweden)

Full Text Available The control of the input voltage of DC-DC converters is frequently required in photovoltaic applications. In this special situation, unlike conventional converters, the output voltage is constant and the input voltage is controlled. This paper deals with the analysis and the control of the buck converter with constant output voltage and variable input.O controle da tensão de entrada de conversores DC-DC é freqüentemente necessário em aplicações com energia fotovoltaica. Nesta situação especial, diferentemente do que ocorre com conversores convencionais, a tensão de saída é constante e a tensão de entrada é variável. Este artigo versa sobre a análise e o controle do conversor buck com tensão de saída constante e tensão de entrada variável.

Marcelo Gradella Villalva

2008-12-01

424

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

425

Energy-conservation approach to modeling PWM dc-dc converters

A new systematic method is presented for including parasitic resistances and offset voltage sources of power switches into averaged dynamic large-signal, dc, and small-signal circuit models of pulse-width modulation (PWM) converters operating in continuous conduction mode (CCM). This method is based on the principle of energy conservation. The proposed approach takes into account the inductor current ripple. With zero-ripple current simplification, the presented method gives the same results as the state-space averaging method. Reflection rules are introduced and used to simplify the models. As an example, a procedure of modeling the PWM buck converter is detailed.

Czarkowski, Dariusz; Kazimierczuk, Marian K.

1993-07-01

426

Buck-Converter Photovoltaic Simulator

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a Photovoltaic Simulator Simulation using Buck Converter with analysis using bode diagram. A state space simulator model is derived to provide a detail non-linear model. The PV Static Model is modified by adding a low pass filter in order to avoid an algebraic loop problem and able to analyze easier. PV simulator is realized by controlling buck converter’s current using PI Controller with reference from PV model. Then the model is linearized which is used for analysis purpose. The system is analyzed using bode diagram for its output voltage against its inputs of solar irradiance and cell’s temperature. The Load, Proportional Gain Kp, and Integral Gain Ki are varied to observe their effects into the system stability. It is noticed that the limits of gain stability system are so high at all values of load and gains so the Buck-Converter Photovoltaic Simulator, which is proposed here, can be declared as a robust system.

Feri Yusivar

2011-10-01

427

Multiphase High-Frequency Isolated DC-DC Converter for Industrial Applications

Industrial applications such as welding, plasma cutting, and surface hardening require a large DC current at low voltage. In such applications, the rating of power supply varies from few kilowatts to hundreds of kilowatts. The power supply employs in such applications particularly in arc welding process is expected to operate from open-circuit (no-load) to short-circuit (when the electrode sticks to the workpiece for a short span of time) quickly. In this paper, high-frequency isolated multiphase DC-DC converter is proposed which is well suited for aforementioned applications. Based on mathematical analysis, a simulation study with 5 kW, 5 V/1,000 A proposed model is carried out using Simulink block set and Sim Power System tool box and its performances are evaluated under symmetrical control methods. To verify the simulation results, scaled prototype model of rating 1.5 V/100 A is developed and tested with aforementioned control method under different operating conditions. In comparison with conventional welding power supply employed in many industries, the performance of proposed converter is improved significantly in terms of size and weight, efficiency and dynamic response.

Maurya, Rakesh; Srivastava, S. P.; Agarwal, Pramod

2014-01-01

428

Fast response double series resonant high-voltage DC-DC converter

International Nuclear Information System (INIS)

In this paper, a novel double series resonant high-voltage dc-dc converter with dual-mode pulse frequency modulation (PFM) control scheme is proposed. The proposed topology consists of two series resonant tanks and hence two resonant currents flow in each switching period. Moreover, it consists of two high-voltage transformer with the leakage inductances are absorbed as resonant inductor in the series resonant tanks. The secondary output of both transformers are rectified and mixed before supplying to load. In the resonant mode operation, the series resonant tanks are energized alternately by controlling two Insulated Gate Bipolar Transistor (IGBT) switches with pulse frequency modulation (PFM). This topology operates in discontinuous conduction mode (DCM) with all IGBT switches operating in zero current switching (ZCS) condition and hence no switching loss occurs. To achieve fast rise in output voltage, a dual-mode PFM control during start-up of the converter is proposed. In this operation, the inverter is started at a high switching frequency and as the output voltage reaches 90% of the target value, the switching frequency is reduced to a value which corresponds to the target output voltage. This can effectively reduce the rise time of the output voltage and prevent overshoot. Experimental results collected from a 100-W laboratory prototype are presented to verify the effectiveness of the proposed system.

429

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

430

Fast response double series resonant high-voltage DC-DC converter

In this paper, a novel double series resonant high-voltage dc-dc converter with dual-mode pulse frequency modulation (PFM) control scheme is proposed. The proposed topology consists of two series resonant tanks and hence two resonant currents flow in each switching period. Moreover, it consists of two high-voltage transformer with the leakage inductances are absorbed as resonant inductor in the series resonant tanks. The secondary output of both transformers are rectified and mixed before supplying to load. In the resonant mode operation, the series resonant tanks are energized alternately by controlling two Insulated Gate Bipolar Transistor (IGBT) switches with pulse frequency modulation (PFM). This topology operates in discontinuous conduction mode (DCM) with all IGBT switches operating in zero current switching (ZCS) condition and hence no switching loss occurs. To achieve fast rise in output voltage, a dual-mode PFM control during start-up of the converter is proposed. In this operation, the inverter is started at a high switching frequency and as the output voltage reaches 90% of the target value, the switching frequency is reduced to a value which corresponds to the target output voltage. This can effectively reduce the rise time of the output voltage and prevent overshoot. Experimental results collected from a 100-W laboratory prototype are presented to verify the effectiveness of the proposed system.

Lee, S. S.; Iqbal, S.; Kamarol, M.

2012-10-01

431

A magnetic thin film inductor and its application to a MHz switching dc-dc converter

Energy Technology Data Exchange (ETDEWEB)

The authors propose a novel structured magnetic thin film inductor using rotation magnetization only. The thin film inductor has a sandwich structure, which consists of a double-rectangular spiral coil between top and bottom CoZrNb amorphous thin films. The sputtered CoZrNb amorphous magnetic thin films have uniaxial magnetic anisotropy induced by direct current field annealing. The easy magnetization axis is directed to the main axis of the rectangular spiral coil. Hence, only the rotation magnetization process dominates in this device. The typical specifications are as follows: 3.5 x 5.5 mm in size, inductance of 1 [mu]H constant up to 10 MHZ, and a quality factor of 10 at 10 MHz. A MHz switching chopper dc-dc converter has been developed by using this thin film inductor, bare-chip semiconductor devices (a power MOSFET and a Schottky barrier diode), and a multilayer ceramic capacitor. This converter with a 0.1 cc volume has an output power over 1 W at 5 MHz switching, and the power density exceeds 10 W/cc (160 W/in.[sup 3]).

Sato, Toshiro; Tomita, Hiroshi; Sawabe, Atsuhito; Inoue, Tetsuo; Mizoguchi, Tetsuhiko; Sahashi, Masashi (Toshiba Corp., Kawasaki (Japan))

1994-03-01

432

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

433

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

434

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

435

Pulse Current Regenerative Resonant Snubber-Assisted Two-Switch Flyback Type ZVS PWM DC-DC Converter

In this paper, a two-switch high frequency flyback transformer type zero voltage soft switching PWM DC-DC converter using IGBTs is proposed. Effective applications for this power converter can be found in auxiliary power supplies of rolling stock transportation and electric vehicles. This power converter is basically composed of two active power switches and a flyback high frequency transformer. In addition to these, two passive lossless snubbers with power regeneration loops for energy recovery, consisting of a three winding auxiliary high frequency transformer, auxiliary capacitors and diodes are introduced to achieve zero voltage soft switching from light to full load conditions. Furthermore, this power converter has some advantages such as low cost circuit configuration, simple control scheme and high efficiency. Its operating principle is described and to determine circuit parameters, some practical design considerations are discussed. The effectiveness of the proposed power converter is evaluated and compared with the hard switching PWM DC-DC converter from an experimental point of view and the comparative electromagnetic conduction and radiation noise characteristics of both DC-DC power converter circuits are also depicted.

Inaba, Claudio Y.; Konishi, Yoshihiro; Nakaoka, Mutsuo

436

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

437

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Seyezhai, R.; Harinee Harinee; Nagarajan Nagarajan

2012-01-01

438

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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. T...

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

2010-01-01

439

A 1.6-kW, 110-kHz dc-dc converter optimized for IGBT's

A full bridge dc-dc converter using a zero-current and zero-voltage switching technique is described. This circuit utilizes the characteristics of the IGBT to achieve power and frequency combinations that are much higher than previously reported for this device. Experimental results are included for a 1.6-kW, 110-kHz converter with 95 percent efficiency.

Chen, Keming; Stuart, Thomas A.

1993-01-01

440

Developments on DC/DC converters for the LHC experiment upgrades

Prototypes of DC/DC power and Point of Load (PoL) converters were designed and built with the aim of satisfying the foreseen working parameters of the High Luminosity (HL) LHC experiments, using both Silicon (Si) MOSFETs and/or more recent devices substantiated of better power performance, like Silicon Carbide (SiC) and Gallium Nitride (GaN) transistors. Optimization of their design, based on the comparison between the simulated and measured thermal, electrical and mechanical performance, is in progress, and many improvements with respect to the previous versions are under implementation. We discuss in this paper the results of the last modifications. In addition, many tens of discrete component samples, chosen among the devices commercially available in the three different technologies (Si, SiC and GaN), were electrically characterized and tested under ?-rays, neutron, proton and heavy ion radiation, also using a combined run method. We have also planned to test some commercial DC/DCs under the extreme conditions of radiation and magnetic field expected in the upgrades of the LHC experiments. Here we show the first results on few samples.

Abbate, C.; Alderighi, M.; Baccaro, S.; Busatto, G.; Citterio, M.; Cova, P.; Delmonte, N.; De Luca, V.; Fiore, S.; Gerardin, S.; Ghisolfi, E.; Giuliani, F.; Iannuzzo, F.; Lanza, A.; Latorre, S.; Lazzaroni, M.; Meneghesso, G.; Paccagnella, A.; Rampazzo, F.; Riva, M.; Sanseverino, A.; Silvestri, R.; Spiazzi, G.; Velardi, F.; Zanoni, E.

2014-02-01

441

A Low-Power Asynchronous Step-Down DC-DC Converter for Implantable Devices.

In this paper, we present a fully integrated asynchronous step-down switched capacitor dc-dc conversion structure suitable for supporting ultra-low-power circuits commonly found in biomedical implants. The proposed converter uses a fully digital asynchronous state machine as the heart of the control circuitry to generate the drive signals. To minimize the switching losses, the asynchronous controller scales the switching frequency of the drive signals according to the loading conditions. It also turns on additional parallel switches when needed and has a backup synchronous drive mode. This circuit regulates load voltages from 300 mV to 1.1 V derived from a 1.2-V input voltage. A total of 350 pF on-chip capacitance was implemented to support a maximum of 230-? W load power, while providing efficiency up to 80%. The circuit validating the proposed concepts was fabricated in 0.13- ?m complementary metal-oxide semiconductor technology. Experimental test results confirm the expected functionality and performance of the proposed circuit. PMID:23851480

Al-Terkawi Hasib, Omar; Sawan, M; Savaria, Y

2011-06-01

442

Total ionizing dose effects of DC-DC power converter used in satellite

International Nuclear Information System (INIS)

The total ionizing dose effects and annealing effects of DVHF2812DF and DVTR2815DF DC-DC power converters were investigated. The typical electrical parameters, such as input current, output current, output voltage, and input current of inhibition mode, as functions of the total dose with different loads and different input voltages were discussed. The relationships between these parameters and the annealing time were observed. The experiment results show that when annealing at room temperature, the trapped holes in deeper energy levels anneal little, which results in dramatic changes of the electric parameters of the DVHF2812DF device when irradiated with extra dose irradiation. However, these parameters go back to the initial values when annealing at high temperature. There are more changes of the electric parameters under the full power loaded situation than other conditions. The input current under inhibition mode can be considered as a sensitive parameter in the evaluation of the radiation-hardened levels of the devices. (authors)

443

Development of a Novel Bi-Directional Isolated Multiple-Input DC-DC Converter

Energy Technology Data Exchange (ETDEWEB)

There is vital need for a compact, lightweight, and efficient energy-storage system that is both affordable and has an acceptable cycle life for the large-scale production of electric vehicles (EVs) and hybrid electric vehicles (HEVs). Most of the current research employs a battery-storage unit (BU) combined with a fuel cell (FC) stack in order to achieve the operating voltage-current point of maximum efficiency for the FC system. A system block diagram is shown in Fig.1.1. In such a conventional arrangement, the battery is sized to deliver the difference between the energy required by the traction drive and the energy supplied by the FC system. Energy requirements can increase depending on the drive cycle over which the vehicle is expected to operate. Peak-power transients result in an increase of losses and elevated temperatures which result in a decrease in the lifetime of the battery. This research will propose a novel two-input direct current (dc) dc to dc converter to interface an additional energy-storage element, an ultracapacitor (UC), which is shown in Fig.1.2. It will assist the battery during transients to reduce the peak-power requirements of the battery.

Li, H.

2005-10-24

444

Evaluating neural control with optimal architecture for DC/DC converter

Directory of Open Access Journals (Sweden)

-power equipment raises great design challenges due to the mathematical model’s complexity and its highly nonlinear dynamic characteristics. Artificial intelligence techniques, such as neuronal networks, suppose great improvements in design and final per- formance, given their capacity for learning complex dynamics and generalising their behaviour. This work was aimed at propo- sing (and evaluating dynamic response later on direct control link with neuronal networks which also allowed eliminating test ele- ments and error in its design. Artificial neuronal network-based direct control was designed as well as possible using bio-inspired 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 performan- ce; 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

2010-05-01

445

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

446