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Sample records for units buck boost

  1. Bidirectional buck boost converter

    Science.gov (United States)

    Esser, Albert Andreas Maria

    1998-03-31

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

  2. Buck-Buck- Boost Regulatr (B3R)

    Science.gov (United States)

    Mourra, Olivier; Fernandez, Arturo; Landstroem, Sven; Tonicello, Ferdinando

    2011-10-01

    In a satellite, the main function of a Power Conditioning Unit (PCU) is to manage the energy coming from several power sources (usually solar arrays and battery) and to deliver it continuously to the users in an appropriate form during the overall mission. The objective of this paper is to present an electronic switching DC-DC converter called Buck-Buck-Boost Regulator (B3R) that could be used as a modular and recurrent solution in a PCU for regulated or un- regulated 28Vsatellite power bus classes. The power conversion stages of the B3R topology are first described. Then theoretical equations and practical tests illustrate how the converter operates in term of power conversion, control loops performances and efficiency. The paper finally provides some examples of single point failure tolerant implementation using the B3R.

  3. Series Connected Buck-Boost Regulator

    Science.gov (United States)

    Birchenough, Arthur G. (Inventor)

    2006-01-01

    A Series Connected Buck-Boost Regulator (SCBBR) that switches only a fraction of the input power, resulting in relatively high efficiencies. The SCBBR has multiple operating modes including a buck, a boost, and a current limiting mode, so that an output voltage of the SCBBR ranges from below the source voltage to above the source voltage.

  4. Computer simulations of optimum boost and buck-boost converters

    Science.gov (United States)

    Rahman, S.

    1982-01-01

    The development of mathematicl models suitable for minimum weight boost and buck-boost converter designs are presented. The facility of an augumented Lagrangian (ALAG) multiplier-based nonlinear programming technique is demonstrated for minimum weight design optimizations of boost and buck-boost power converters. ALAG-based computer simulation results for those two minimum weight designs are discussed. Certain important features of ALAG are presented in the framework of a comprehensive design example for boost and buck-boost power converter design optimization. The study provides refreshing design insight of power converters and presents such information as weight annd loss profiles of various semiconductor components and magnetics as a function of the switching frequency.

  5. Computer simulations of optimum boost and buck-boost converters

    Science.gov (United States)

    Rahman, S.

    1982-09-01

    The development of mathematicl models suitable for minimum weight boost and buck-boost converter designs are presented. The facility of an augumented Lagrangian (ALAG) multiplier-based nonlinear programming technique is demonstrated for minimum weight design optimizations of boost and buck-boost power converters. ALAG-based computer simulation results for those two minimum weight designs are discussed. Certain important features of ALAG are presented in the framework of a comprehensive design example for boost and buck-boost power converter design optimization. The study provides refreshing design insight of power converters and presents such information as weight annd loss profiles of various semiconductor components and magnetics as a function of the switching frequency.

  6. Transformer Isolated Buck-Boost Converters

    Directory of Open Access Journals (Sweden)

    Barry W. Williams

    2016-12-01

    Full Text Available Of the single-switch dc-to-dc converters, those with the buck-boost voltage transfer function offer most potential for transformer coupling, hence isolation, at the kilowatt level. This paper highlights the limitations of the traditional magnetic coupled, buck-boost topology. Then four split-capacitor transformer-coupled topologies (specifically the Cuk, sepic, zeta, and a new, converters with a common ac equivalent circuit are explored, that do not temporarily store core magnetic energy as does the traditional isolated buck-boost converter nor have a core dc magnetizing current bias, as with the sepic and zeta transformer coupled topologies. Core dc bias capacitive voltage compensation is a practical design constraint in three of the four topologies, while all four must cater for stray and leakage inductance effects. Simulations and experimental results for the new converter at 408W support the transformer-coupled, single-switch dc-to-dc converter concepts investigated.

  7. What is the Best Converter for Low Voltage Fuel Cell Applications- A Buck or Boost?

    DEFF Research Database (Denmark)

    Nymand, Morten; Tranberg, René; Madsen, Mark E.;

    2009-01-01

    Amongst many converter topologies that have been proposed and developed for low voltage fuel cell applications, isolated full-bridge Buck and Boost converters appear to be the most popular. Although the Buck topology is considered to be superior in performance, for particularly being more efficient....... Experimental results of two 1.5 kW prototype Buck and Boost converter units are presented with detailed discussions, and the paper explains why, in contrary to the popular belief, a properly designed Boost topology is superior in performance to Buck topology and more appropriate for low voltage fuel cell......, this claim has never been proved with a ‘proper’ comparison to the Boost topology. This paper presents a comprehensive comparison between Buck and Boost topologies, which are designed for the same specifications and tested under the same and stringent operating conditions using precision measuring equipment...

  8. What is the Best Converter for Low Voltage Fuel Cell Applications- A Buck or Boost?

    DEFF Research Database (Denmark)

    Nymand, Morten; Tranberg, René; Madsen, Mark E.

    2009-01-01

    Amongst many converter topologies that have been proposed and developed for low voltage fuel cell applications, isolated full-bridge Buck and Boost converters appear to be the most popular. Although the Buck topology is considered to be superior in performance, for particularly being more efficient......, this claim has never been proved with a ‘proper’ comparison to the Boost topology. This paper presents a comprehensive comparison between Buck and Boost topologies, which are designed for the same specifications and tested under the same and stringent operating conditions using precision measuring equipment....... Experimental results of two 1.5 kW prototype Buck and Boost converter units are presented with detailed discussions, and the paper explains why, in contrary to the popular belief, a properly designed Boost topology is superior in performance to Buck topology and more appropriate for low voltage fuel cell...

  9. Diode-Assisted Buck-Boost Voltage-Source Inverters

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Teodorescu, Remus;

    2009-01-01

    This paper proposes a number of diode-assisted buck-boost voltage-source inverters with a unique X-shaped diode-capacitor network inserted between the inverter circuitry and dc source for producing a voltage gain that is comparatively higher than those of other buck-boost conversion techniques...

  10. Solid state light source driver establishing buck or boost operation

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, Fred

    2017-08-29

    A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boost converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.

  11. Diode-Assisted Buck-Boost Current Source Inverters

    DEFF Research Database (Denmark)

    Gao, F.; Cai, Liang; Loh, P.C.

    2007-01-01

    This paper presents a couple of novel current source inverters (CSIs) with the enhanced current buckboost capability. With the unique diode-inductor network added between current source inverter circuitry and current boost elements, the proposed buck-boost current source inverters demonstrate...... a double current boost capability when comparing with the recently reported buckboost CSIs. For modulating the presented CSIs, two modulation schemes are proposed for achieving either optimized harmonic performance or minimal commutation count, meanwhile keeping the important current buck-boost operation...

  12. Series-Connected Buck Boost Regulators

    Science.gov (United States)

    Birchenough, Arthur G.

    2005-01-01

    A series-connected buck boost regulator (SCBBR) is an electronic circuit that bucks a power-supply voltage to a lower regulated value or boosts it to a higher regulated value. The concept of the SCBBR is a generalization of the concept of the SCBR, which was reported in "Series-Connected Boost Regulators" (LEW-15918), NASA Tech Briefs, Vol. 23, No. 7 (July 1997), page 42. Relative to prior DC-voltage-regulator concepts, the SCBBR concept can yield significant reductions in weight and increases in power-conversion efficiency in many applications in which input/output voltage ratios are relatively small and isolation is not required, as solar-array regulation or battery charging with DC-bus regulation. Usually, a DC voltage regulator is designed to include a DC-to-DC converter to reduce its power loss, size, and weight. Advances in components, increases in operating frequencies, and improved circuit topologies have led to continual increases in efficiency and/or decreases in the sizes and weights of DC voltage regulators. The primary source of inefficiency in the DC-to-DC converter portion of a voltage regulator is the conduction loss and, especially at high frequencies, the switching loss. Although improved components and topology can reduce the switching loss, the reduction is limited by the fact that the converter generally switches all the power being regulated. Like the SCBR concept, the SCBBR concept involves a circuit configuration in which only a fraction of the power is switched, so that the switching loss is reduced by an amount that is largely independent of the specific components and circuit topology used. In an SCBBR, the amount of power switched by the DC-to-DC converter is only the amount needed to make up the difference between the input and output bus voltage. The remaining majority of the power passes through the converter without being switched. The weight and power loss of a DC-to-DC converter are determined primarily by the amount of power

  13. Component-Minimized Buck-Boost Voltage Source Inverters

    DEFF Research Database (Denmark)

    Gao, F.; Loh, P.C.; Blaabjerg, Frede;

    2007-01-01

    the additional voltage relationship between dc input and ac output which is beyond the expectation when continuous inductor current is assumed. These theoretical findings, together with the inverter practicality, have been confirmed in Matlab/PLECS simulations and  experimentally using laboratory implemented......This paper presents the design of buck-boost B4 inverters that can be derived from either Ćuk- or SEPIC-derived buck-boost B6 inverters. Unlike traditional inverters, the integration of front-end voltage boost circuitry and inverter circuitry allows it to perform buck-boost voltage inversion....... In order to form a distinct neutral potential in the corresponding voltage boost circuitry for correct B4 inverter operation, necessary modifications are derived step by step. The resulted dc networks with symmetrical placement of passive components allow complete charging and equal energy distribution...

  14. Nonlinear program based optimization of boost and buck-boost converter designs

    Science.gov (United States)

    Rahman, S.; Lee, F. C.

    1981-01-01

    The facility of an Augmented Lagrangian (ALAG) multiplier based nonlinear programming technique is demonstrated for minimum-weight design optimizations of boost and buck-boost power converters. Certain important features of ALAG are presented in the framework of a comprehensive design example for buck-boost power converter design optimization. The study provides refreshing design insight of power converters and presents such information as weight and loss profiles of various semiconductor components and magnetics as a function of the switching frequency.

  15. Buck-boost converter feedback controller design via evolutionary search

    Science.gov (United States)

    Sundareswaran, K.; Devi, V.; Nadeem, S. K.; Sreedevi, V. T.; Palani, S.

    2010-11-01

    Buck-boost converters are switched power converters. The model of the converter system varies from the ON state to the OFF state and hence traditional methods of controller design based on approximate transfer function models do not yield good dynamic response at different operating points of the converter system. This article attempts to design a feedback controller for a buck-boost type dc-dc converter using a genetic algorithm. The feedback controller design is perceived as an optimisation problem and a robust controller is estimated through an evolutionary search. Extensive simulation and experimental results provided in the article show the effectiveness of the new approach.

  16. Integrated buck-boost converter with Matrix-POL architecture

    OpenAIRE

    2013-01-01

    In this study, integrated buck-boost converter with the Matrix-POL power supply system is proposed. From the simulation results, the validity of the Matrix-POL is revealed. The results revealed that the fast response to the load current and the voltage change can be done with duty and parallel number control by the proposed system.

  17. Buck-Boost Current-Source Inverters With Diode-Inductor Network

    DEFF Research Database (Denmark)

    Gao, Feng; Liang, Chao; Loh, Poh Chiang

    2009-01-01

    This paper presents a number of novel currentsource inverters (CSIs) with enhanced current buck-boost capability. By adding a unique diode-inductor network between the inverter circuitry and current-boost elements, the proposed buck-boost CSIs demonstrate a doubling of current-boost capability......, as compared with other recently reported buck-boost CSIs. For controlling the proposed CSIs, two modulation schemes are designed for achieving either optimized harmonic performance or minimized commutation count without influencing the inverter current buck-boost gain. These theoretical findings were...

  18. High Efficient Universal Buck Boost Solar Array Regulator SAR Module

    Science.gov (United States)

    Kimmelmann, Stefan; Knorr, Wolfgang

    2014-08-01

    The high efficient universal Buck Boost Solar Array Regulator (SAR) module concept is applicable for a wide range of input and output voltages. The single point failure tolerant SAR module contains 3 power converters for the transfer of the SAR power to the battery dominated power bus. The converters are operating parallel in a 2 out of 3 redundancy and are driven by two different controllers. The output power of one module can be adjusted up to 1KW depending on the requirements. The maximum power point tracker (MPPT) is placed on a separate small printed circuit board and can be used if no external tracker signal is delivered. Depending on the mode and load conditions an efficiency of more than 97% is achievable. The stable control performance is achieved by implementing the magnetic current sense detection. The sensed power coil current is used in Buck and Boost control mode.

  19. Circuit Simulation for Solar Power Maximum Power Point Tracking with Different Buck-Boost Converter Topologies

    OpenAIRE

    2014-01-01

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

  20. Modeling and Simulation of Buck-Boost Converter with Voltage Feedback Control

    OpenAIRE

    2015-01-01

    In order to design the control system, it is necessary to have an exact model of buck-boost converter. This paper put forward the transfer function model of buck-boost converter by the state-space average method. The open-loop transfer function model of uncompensated system is deduced according to the mathematic model of the buck-boost converter, the controller is designed according to frequency domain. The phase and magnitude margin of the open-loop system of the buck-boost converter with co...

  1. Analysis of Non-minimum Phase in Buck-Boost Converter

    OpenAIRE

    2016-01-01

    In this paper, relations among the parameters of the non-minimum phase for the Buck-Boost converter are studied. It is demonstrated that when the Buck-Boost converter works in Buck mode, the negative regulation voltage is determined by the converter with the pre-designed inductor and load as the duty ratio D0.382, and the duty ratio has a limited effect on the negative regulation voltage of the converter; when the Buck-Boost converter works in Boost mode,the negative regulation voltage is det...

  2. Nonlinear Phenomena in Buck-Boost Power Factor Correction Converter

    Directory of Open Access Journals (Sweden)

    Mehrnoosh Vatani

    2013-01-01

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

  3. A TEG Efficiency Booster with Buck-Boost Conversion

    Science.gov (United States)

    Wu, Hongfei; Sun, Kai; Zhang, Junjun; Xing, Yan

    2013-07-01

    A thermoelectric generator (TEG) efficiency booster with buck-boost conversion and power management is proposed as a TEG battery power conditioner suitable for a wide TEG output voltage range. An inverse-coupled inductor is employed in the buck-boost converter, which is used to achieve smooth current with low ripple on both the TEG and battery sides. Furthermore, benefiting from the magnetic flux counteraction of the two windings on the coupled inductor, the core size and power losses of the filter inductor are reduced, which can achieve both high efficiency and high power density. A power management strategy is proposed for this power conditioning system, which involves maximum power point tracking (MPPT), battery voltage control, and battery current control. A control method is employed to ensure smooth switching among different working modes. A modified MPPT control algorithm with improved dynamic and steady-state characteristics is presented and applied to the TEG battery power conditioning system to maximize energy harvesting. A 500-W prototype has been built, and experimental tests carried out on it. The power efficiency of the prototype at full load is higher than 96%, and peak efficiency of 99% is attained.

  4. Cascaded Buck-Boost AC/AC converter%级联式Buck-Boost AC/AC变换器

    Institute of Scientific and Technical Information of China (English)

    张友军; 丁明昌; 任永保; 王阿敏; 翁振明

    2010-01-01

    详细分析了Buck型和Boost型AC/AC变换器的工作原理及其控制方法,在此基础上提出了一种新型级联式Buck-Boost AC/AC变换器及其三模式控制策略.三模式控制策略是比较输入电压与基准输出电压的大小,使得变换器只有3种工作模式:Buck模式、Boost模式和滤波模式.该电路虽然由Buck型和Boost型AC/AC变换器2级变换器级联而成,并采用2级占空比调制,但实际上最多只存在一级功率变换,具有控制简单、变换效率高、开关管电压应力低等优点.仿真结果证明了级联式Buck-Boost AC/AC变换器及其控制策略的可行性和理论分析的正确性.

  5. Design and Control for the Buck-Boost Converter Combining 1-Plus-D Converter and Synchronous Rectified Buck Converters

    OpenAIRE

    2015-01-01

    In this paper, a design and control for the buck-boost converter, i.e., 1-plus-D converter with a positive output voltage, is presented, which combines the 1-plus-D converter and the synchronous rectified (SR) buck converter. By doing so, the problem in voltage bucking of the 1-plus-D converter can be solved, thereby increasing the application capability of the 1-plus-D converter. Since such a converter operates in continuous conduction mode inherently, it possesses the nonpulsating output cu...

  6. A Novel Quadratic Buck-Boost DC-DC Converter without Floating Gate-Driver

    DEFF Research Database (Denmark)

    Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen

    2016-01-01

    for floating gate driver. In addition, the voltage stress of one of the switches is lower than the existing quadratic buck-boost converters. Performance of the analytical results is validated using both simulation in MATLAB/SIMULINK and experimental tests where the proposed converter is evaluated in both buck...

  7. A Novel Quadratic Buck-Boost DC-DC Converter without Floating Gate-Driver

    DEFF Research Database (Denmark)

    Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen

    2016-01-01

    for floating gate driver. In addition, the voltage stress of one of the switches is lower than the existing quadratic buck-boost converters. Performance of the analytical results is validated using both simulation in MATLAB/SIMULINK and experimental tests where the proposed converter is evaluated in both buck...

  8. Modeling and Simulation of Buck-Boost Converter with Voltage Feedback Control

    Directory of Open Access Journals (Sweden)

    Zhou Xuelian

    2015-01-01

    Full Text Available In order to design the control system, it is necessary to have an exact model of buck-boost converter. This paper put forward the transfer function model of buck-boost converter by the state-space average method. The open-loop transfer function model of uncompensated system is deduced according to the mathematic model of the buck-boost converter, the controller is designed according to frequency domain. The phase and magnitude margin of the open-loop system of the buck-boost converter with compensator have both been increased. After compensating, this control system has the advantages of small overshoot and short settling time. It can also improve control system’s real time property and anti-interference ability.

  9. An Effective Wind Energy System based on Buck-boost Controller

    Directory of Open Access Journals (Sweden)

    N. Prakash

    2013-06-01

    Full Text Available In Domestic Wind Machines, if the wind speed is low, the output voltage is not sufficient to charge the battery as it is lower than the rated charging voltage of the battery. This limits the overall efficiency of the Wind Machine to 20%. This study proposed to design and develop a Buck Boost Controller for the effective utilization of the wind machine. By implementing a controller based Buck Boost converter, the voltage produced at the lower wind speeds can also be utilized effectively by boosting it to the rated charging voltage of the battery. Also if the wind speed is high (>14 m/s, the DC output voltage will increase to more than 65 V. The converter bucks this high voltage to the nominal battery charging voltage (52 V, thereby protecting the battery from over charging voltage. Thus the effective utilization of the wind machine has been achieved by the use of the proposed Buck Boost Controller.

  10. 基于Matlab的Boost-Buck Chopper的建模与仿真%Modeling and simulation of Boost-Buck Chopper based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    孟庆波; 崔刚

    2012-01-01

    对Matlab进行了简单介绍,建立了IGBT的仿真模型,运用Matlab/Simulink和Power System工具对Boost- Buck Chopper进行建模、参数选择和仿真分析.与常规电路分析方法相比,该方法具有很大的优越性.%The paper takes a brief introduction to MATLAB, and establishes a simulation model ofIGBT. It uses Matlab/Simulink and Power System tools to model, chooses parameters and simulatesBoost-Buck Chopper. Compared with conventional circuit analysis methods, this method has greatadvantages.

  11. Smooth-Transition Simple Digital PWM Modulator for Four-Switch Buck-Boost Converters

    Science.gov (United States)

    Rodriguez, Alberto; Rodriguez, Miguel; Vazquez, Aitor; Maija, Pablo F.; Sebastian, Javier

    2014-08-01

    Four Switch non-inverting Buck-Boost (4SBB) converters are extensively used in non-isolated applications where voltage step-up and step-down are required. In order to achieve high efficiency operation it is preferred to control the 4SBB as a Buck or Boost converter, depending on the input/output voltage ratio. However, when input and output voltages are close this approach requires near- unity conversion ratios, which are difficult to achieve in practice. Several alternative operating modes have been proposed in the literature to overcome this issue. In particular, operating the 4SBB as a Buck and Boost at the same time (Buck+Boost mode) has proven to be adequate to achieve near-unity conversion ratios.This paper proposes a simple, hardware-efficient digital pulse width modulator for a 4SBB that enables operation in Buck, Boost and Buck+Boost modes, thus allowing near-unity conversion ratios, while achieving smooth transitions between the different modes. The proposed modulator is simulated with Simulink and experimentally demonstrated using a 500W 4SBB converter with 24V input voltage and 12V-36V output voltage range.

  12. Design and Control for the Buck-Boost Converter Combining 1-Plus-D Converter and Synchronous Rectified Buck Converters

    Directory of Open Access Journals (Sweden)

    Jeevan Naik

    2015-06-01

    Full Text Available In this paper, a design and control for the buck-boost converter, i.e., 1-plus-D converter with a positive output voltage, is presented, which combines the 1-plus-D converter and the synchronous rectified (SR buck converter. By doing so, the problem in voltage bucking of the 1-plus-D converter can be solved, thereby increasing the application capability of the 1-plus-D converter. Since such a converter operates in continuous conduction mode inherently, it possesses the nonpulsating output current, thereby not only decreasing the current stress on the output capacitor but also reducing the output voltage ripple. Above all, both the 1-plus-D converter and the SR buck converter, combined into a buck–boost converter with no right-half plane zero, use the same power switches, thereby causing the required circuit to be compact and the corresponding cost to be down. Furthermore, during the magnetization period, the input voltage of the 1-plus-D converter comes from the input voltage source, whereas during the demagnetization period, the input voltage of the 1-plus-D converter comes from the output voltage of the SR buck converter.

  13. ASDTIC control and standardized interface circuits applied to buck, parallel and buck-boost dc to dc power converters

    Science.gov (United States)

    Schoenfeld, A. D.; Yu, Y.

    1973-01-01

    Versatile standardized pulse modulation nondissipatively regulated control signal processing circuits were applied to three most commonly used dc to dc power converter configurations: (1) the series switching buck-regulator, (2) the pulse modulated parallel inverter, and (3) the buck-boost converter. The unique control concept and the commonality of control functions for all switching regulators have resulted in improved static and dynamic performance and control circuit standardization. New power-circuit technology was also applied to enhance reliability and to achieve optimum weight and efficiency.

  14. Li-Ion Battery Charging with a Buck-Boost Power Converter for a Solar Powered Battery Management System

    OpenAIRE

    2013-01-01

    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...

  15. The Series Connected Buck Boost Regulator Concept for High Efficiency Light Weight DC Voltage Regulation

    Science.gov (United States)

    Birchenough, Arthur G.

    2003-01-01

    Improvements in the efficiency and size of DC-DC converters have resulted from advances in components, primarily semiconductors, and improved topologies. One topology, which has shown very high potential in limited applications, is the Series Connected Boost Unit (SCBU), wherein a small DC-DC converter output is connected in series with the input bus to provide an output voltage equal to or greater than the input voltage. Since the DC-DC converter switches only a fraction of the power throughput, the overall system efficiency is very high. But this technique is limited to applications where the output is always greater than the input. The Series Connected Buck Boost Regulator (SCBBR) concept extends partial power processing technique used in the SCBU to operation when the desired output voltage is higher or lower than the input voltage, and the implementation described can even operate as a conventional buck converter to operate at very low output to input voltage ratios. This paper describes the operation and performance of an SCBBR configured as a bus voltage regulator providing 50 percent voltage regulation range, bus switching, and overload limiting, operating above 98 percent efficiency. The technique does not provide input-output isolation.

  16. Analysis of Non-minimum Phase in Buck-Boost Converter

    Directory of Open Access Journals (Sweden)

    Huang Jinfeng

    2016-01-01

    Full Text Available In this paper, relations among the parameters of the non-minimum phase for the Buck-Boost converter are studied. It is demonstrated that when the Buck-Boost converter works in Buck mode, the negative regulation voltage is determined by the converter with the pre-designed inductor and load as the duty ratio D0.382, and the duty ratio has a limited effect on the negative regulation voltage of the converter; when the Buck-Boost converter works in Boost mode,the negative regulation voltage is determined jointly by the converter with its pre-designed inductor, load and duty cycle, for which performs that the higher the output voltage is (i.e., the greater the duty ratio is,the more severe undershoot of the voltage will be. The conclusion of this paper has a guidance meaning for decreasing the negative regulation voltage of the Buck-Boost converter. Finally the correctness of the analysis for the non-minimum phase is verified by simulations and experiments.

  17. Non-Inverting Buck-Boost Converter for Fuel Cell Applications

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  18. 一种新型Buck-Boost变换器%A Novel Buck-Boost Converter

    Institute of Scientific and Technical Information of China (English)

    高飞; 蒋赢; 赵小妹; 潘俊民

    2010-01-01

    提出了一种新型Buck-Boost变换器,与传统的Buck-Boost变换器相比,该电路利用开关电容网络,能在相同的输入电压和开关管占空比情况下具有更好的降压效果.对该新型Buck-Boost变换器的工作原理进行了分析,并通过仿真和实验验证了该方案的可行性.实验表明,该新型Buck-Boost变换器能够实现较好的降压效果,输出效果良好.

  19. Study on Nonlinear Phenomena in Buck-Boost Converter with Switched-Inductor Structure

    OpenAIRE

    2013-01-01

    The switched-inductor structure can be inserted into a traditional Buck-Boost converter to get a high voltage conversion ratio. Nonlinear phenomena may occur in this new converter, which might well lead the system to be unstable. In this paper, a discrete iterated mapping model is established when the new Buck-Boost converter is working at continuous conduction current-controlled mode. On the basis of the discrete model, the bifurcation diagrams and Poincare sections are drawn and then used t...

  20. PWM Technique for Non-Isolated Three-Phase Buck-Boost PFC Converter

    Science.gov (United States)

    Morizane, Toshimitsu; Shimomori, Wataru; Taniguchi, Katsunori; Kimura, Noriyuki; Ogawa, Masanori

    The buck-boost power factor corrected (PFC) converter has the wide range of the dc output voltage. A new non-isolated three-phase hard-switching and a soft-switching buck-boost PFC converter are proposed. Removing the three-phase transformer from the converters makes their size more compact and their costs lower. In addition, the new control method based on the PWM technique is proposed in this paper to achieve the high power factor. Complete soft-switching is also achieved under the discontinuous current mode (DCM) operation.

  1. Modeling and Analysis of Transformerless High Gain Buck-boost DC-DC Converters

    Directory of Open Access Journals (Sweden)

    Vu Tran

    2014-12-01

    Full Text Available This paper proposes a transfomerless switched capacitor buck boost converter model, which provides higher voltage gain and higher efficiency when compared to the conventional buck boost converter. The averaged model based on state-space description is analyzed in the paper. The simulation results are presented to confirm the capability of the converter to generate high voltage ratios. The comparison between the proposed model and the traditional model is also provided to reveal the improvement. The proposed converter is suitable for for a wide application which requires high step-up DC-DC converters such as DC micro-grids and solar electrical energy.

  2. A Novel Single Switch Transformerless Quadratic DC/DC Buck-Boost Converter

    DEFF Research Database (Denmark)

    Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen

    2017-01-01

    A novel quadratic buck-boost DC/DC converter is presented in this study. The proposed converter utilizes only one active switch and can step-up/down the input voltage, while the existing single switch quadratic buck/boost converters can only work in step-up or step-down mode. First, the proposed ...... converter is analyzed in steady-state. Then, its performance is validated using simulations in MATLAB/SIMULINK software. Finally, an experimental prototype is built for further verification....

  3. Analisys of Current-Bidirectional Buck-Boost Based Automotive Switch-Mode Audio Amplifier

    DEFF Research Database (Denmark)

    Bolten Maizonave, Gert; Andersen, Michael A. E.; Kjærgaard, Claus

    2011-01-01

    The following study was carried out in order to assess quantitatively the performance of the buck-boost converter when used as switch-mode audio amplifier. It comprises of, to begin with, the delimitation of design criteria based on the state-ofthe- art solution, which is based in a differential...... mode buck-based amplifier with a boost converter as power supply. The averaged switch modelling of the differential mode current bidirectional topology is also used, in order to analyze the steady state and frequency domain behaviour of this converter and parameterize it to meet the design criteria...... in such configuration when applied for audio....

  4. 一种新颖的Buck-Boost变换器%A Novel Buck-Boost Converter

    Institute of Scientific and Technical Information of China (English)

    方宇; 谢勇; 邢岩

    2003-01-01

    提出了一种新颖的两开关电路拓扑,它能工作在宽输入交流电压范围,并实现功率因数校正(PFC).新拓扑与单开关Buck-Boost变换器和传统的两开关串级Buck-Boost变换器及其它Buck-Boost变换器相比有显著的性能改善,如:器件应力及损耗较低,不需要解决浪涌电流问题,电感尺寸也较小.分析了拓扑工作原理,并给出了实验结果.

  5. Topological Design and Modulation Strategy for Buck-Boost Three-Level Inverters

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Gao, F.; Blaabjerg, Frede;

    2007-01-01

    To date, designed topologies for dc-ac inversion with both voltage-buck and boost capabilities are mainly focused on two-level circuitries with extensions to three-level possibilities left nearly unexplored. Contributing to this area of research, this paper presents the design of a number of viable...

  6. Pulse width modulated buck-boost five-level current source inverters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Gao, F.; Loh, P.C.;

    2008-01-01

    This paper presents new five-level current source inverters (CSIs) with voltage/current buck-boost capability. Being different from the existing multilevel CSI, the proposed CSIs were first designed to regulate the flowing path of dc input current by controlling two additional active switches, re...

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

    DEFF Research Database (Denmark)

    Dimopoulos, Emmanouil; Munk-Nielsen, Stig

    2014-01-01

    of commercially-available, high-efficient, high-voltage, low-power semiconductor devices. In this paper, a high-efficient bidirectional tapped-inductor buck-boost converter, addressing high step-up and high step-down voltage conversion ratios, is proposed for energy harvesting applications based on DEAP...

  8. Novel Family of modified qZS buck-boost multilevel inverters with reduced switch count

    DEFF Research Database (Denmark)

    Husev, Oleksandr; Strzelecki, Ryszard; Blaabjerg, Frede

    2015-01-01

    This paper describes a novel family of modified quasi-Z-source buck-boost multilevel inverters with reduced switch count. The inverters are derived by means of the modified inverter configuration with quasi-Z-source networks. The main benefits of the proposed solutions lie in the increased amount...

  9. Circuit Simulation for Solar Power Maximum Power Point Tracking with Different Buck-Boost Converter Topologies

    Directory of Open Access Journals (Sweden)

    Jaw-Kuen Shiau

    2014-08-01

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

  10. A new approach to improve dynamic characteristics of digitally controlled buck-boost dc-dc converter

    OpenAIRE

    2010-01-01

    This paper presents a new digital control buck-boost dc-dc converter with bias model to improve dynamic characteristics. The buck-boost converter needs to respond appropriately to changing input voltage and load change with wide input voltage. This approach makes adjustment to the bias value by input voltage and output current. As a result, it is revealed that not only the dynamic characteristics but also static characteristics can be improved and it is effective for wide range input voltage.

  11. Li-Ion Battery Charging with a Buck-Boost Power Converter for a Solar Powered Battery Management System

    Directory of Open Access Journals (Sweden)

    Chien-Wei Ma

    2013-03-01

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

  12. Incremental Conductance MPPT Algorithm for PV System Implemented Using DC-DC Buck and Boost Converter

    Directory of Open Access Journals (Sweden)

    Dhananjay Choudhary

    2014-08-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Majid Delshad

    2010-03-01

    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.

  14. Fractional order Buck-Boost converter in CCM: modelling, analysis and simulations

    Science.gov (United States)

    Wang, Faqiang; Ma, Xikui

    2014-12-01

    In this paper, the modelling, analysis and the power electronics simulator (PSIM) simulations of the fractional order Buck-Boost converter operating in continuous conduction mode (CCM) operation are investigated. Based on the three-terminal switch device method, the average circuit model of the fractional order Buck-Boost converter is established, and the corresponding DC equivalent circuit model and AC small signal equivalent circuit model are presented. And then, the equilibrium point and the transfer functions are derived. It is found that the equilibrium point is not influenced by the inductor's or the capacitor's order, but both these orders are included in the derived transfer functions. Finally, the comparisons between the theoretical analysis and the PSIM simulations are given for confirmation.

  15. Analysis, control and design of a non-inverting buck-boost converter

    DEFF Research Database (Denmark)

    Almasi, Omid Naghash; Fereshtehpoor, Vahid; Khooban, Mohammad Hassan

    2017-01-01

    In this paper, a new modified fuzzy Two-Level Control Scheme (TLCS) is proposed to control a non-inverting buck-boost converter. Each level of fuzzy TLCS consists of a tuned fuzzy PI controller. In addition, a Takagi–Sugeno–Kang (TSK) fuzzy switch proposed to transfer the fuzzy PI controllers...... to each other in the control system. The major difficulty in designing fuzzy TLCS which degrades its performance is emerging unwanted drastic oscillations in the converter output voltage during replacing the controllers. Thereby, the fuzzy PI controllers in each level of TLCS structure are modified...... to eliminate these oscillations and improve the system performance. Some simulations and digital signal processor based experiments are conducted on a non-inverting buck-boost converter to support the effectiveness of the proposed TLCS in controlling the converter output voltage....

  16. Non-Inverted Buck-Boost Converters with Dual Delta Sigma Modulators

    Science.gov (United States)

    Kobori, Yasunori; Kono, Masashi; Shimizu, Toshihiko; Kobayashi, Haruo

    This paper presents a new control circuit to create high-performance non-inverted Buck-Boost converter with dual ⊿∑ modulations. Experimental load regulation, corresponding to load current steps of ±0.5A, is within 45mVpp, and the efficiency without synchronized rectifier is 83% at input voltage 2.5V and load current 0.8A.

  17. Incremental Conductance MPPT Algorithm for PV System Implemented Using DC-DC Buck and Boost Converter

    OpenAIRE

    2014-01-01

    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 f...

  18. Buck-Boost/Forward Hybrid Converter for PV Energy Conversion Applications

    OpenAIRE

    2014-01-01

    This paper presents a charger and LED lighting (discharger) hybrid system with a PV array as its power source for electronic sign indicator applications. The charger adopts buck-boost converter which is operated in constant current mode to charge lead-acid battery and with the perturb and observe method to extract maximum power of PV arrays. Their control algorithms are implemented by microcontroller. Moreover, forward converter with active clamp circuit is operated in voltage regulation cond...

  19. Analysis of current-bidirectional buck-boost based switch-mode audio amplifier

    DEFF Research Database (Denmark)

    Bolten Maizonave, Gert; Andersen, Michael A. E.; Kjærgaard, Claus

    2011-01-01

    The following studdy was carried out in order to assses quantitatively the performannce of the buck--boost converter whhen used as swiitch-mode audio amplifier. It comprises of, to beggin with, the de limitation of design criteria bassed on the state of-the-art solution, which is based...... in a differential mode buckbased amplifier with a boost converter as power supply. The averaged switch modelling of the differential mode current bidirectional topology is also used, in order to analyze the steady state and frequency-wise behaviour of this converter and parameterize it to meet the design criteria...... in such configuration when applied for audio....

  20. Cross-Regulation Assessment of DIDO Buck-Boost Converter for Renewable Energy Application

    Directory of Open Access Journals (Sweden)

    Deepak Elamalayil Soman

    2017-06-01

    Full Text Available When medium- or high-voltage power conversion is preferred for renewable energy sources, multilevel power converters have received much of the interest in this area as methods for enhancing the conversion efficiency and cost effectiveness. In such cases, multilevel, multi-input multi-output (MIMO configurations of DC-DC converters come to the scenario for integrating several sources together, especially considering the stringent regulatory needs and the requirement of multistage power conversion systems. Considering the above facts, a three-level dual input dual output (DIDO buck-boost converter, as the simplest form of MIMO converter, is proposed in this paper for DC-link voltage regulation. The capability of this converter for cross regulating the DC-link voltage is analyzed in detail to support a three-level neutral point clamped inverter-based grid connection in the future. The cross-regulation capability is examined under a new type of pulse delay control (PDC strategy and later compared with a three-level boost converter (TLBC. Compared to conventional boost converters, the high-voltage three-level buck boost converter (TLBBC with PDC exhibits a wide controllability range and cross regulation capability. These enhanced features are extremely important for better regulating variable output renewable energy sources such as solar, wind, wave, marine current, etc. The simulation and experimental results are provided to validate the claim.

  1. 基于模糊PI的buck-boost变换器控制%Fuzzy PI Control for Buck-boost Converter

    Institute of Scientific and Technical Information of China (English)

    王磊

    2012-01-01

      For the strong nonlinearity of the DC/DC converter, this paper proposes a new fuzzy PI con⁃troller, which combines fuzzy control method with traditional PI dual loop control method. All the details about the fuzzy PI controller are provided, including the key structure, working principle, design process and parame⁃ter tuning method. The overall software and hardware solutions for the controller are designed where TMS320F240 DSP is the control core device. Then as an example, a simulation of buck-boost converter under given parameters is run to verify the close loop behavior of the controller. Simulation results show that the new fuzzy PI controller may greatly enhance the static and dynamic performance of the converter system.%  针对DC/DC变换器的强非线性,提出了一种新的模糊PI控制器,将模糊控制方法与传统线性PI的电压、电流双环控制方法结合形成闭环系统。给出了模糊PI控制器的结构原理、设计过程和参数整定方法,并对给定参数的buck-boost变换器作为实例进行了仿真验证,同时以TMS320F2812DSP为核心控制器件,设计了系统整体实现的软硬件方案。仿真结果表明,新的模糊PI控制器能够较大地提升系统的动、静态性能。

  2. BUCK-BOOST DC/DC变换器RHP零点研究%Right Half Plane Zero Spot Research of BUCK-BOOST DC/DC Converter

    Institute of Scientific and Technical Information of China (English)

    周习祥

    2010-01-01

    对于BUCK-BOOST DC/DC变换器,如何获得较大的稳定裕度和良好的高频瞬态性能一直以来都是令研究人员棘手的问题.要使这种变换器稳定工作,往往需要在一个很低的频率下就滑离控制电路的增益,文章基于变换器的占空比控制方式与电流控制公式分析了右半平面零点的动态特性,为提高电源系统的稳定性提供了理论依据.

  3. 级联Buck-Boost PFC变换器建模及仿真%Modeling and Simulation of Cascaded Buck-Boost AC-DC Converter

    Institute of Scientific and Technical Information of China (English)

    郭学军; 刘以建

    2016-01-01

    文中采用状态空间平均法对级联Buck-Boost AC-DC变换器进行了小信号建模分析,提出了一种基于瞬时功率守恒的新的平均电流控制(ACC)技术.通过这种新的控制技术能够使得输入电流波形接近正弦波且与输入电压同相位,总的谐波扰动小于3%.最后通过PSIM仿真实验,验证了这种新的控制方法的可行性和优越性.

  4. BUCK-BOOST变换器的输出能量分析及电感电容优化设计%Output Energy Analysis and Optimization Design of Inductance and Capacitance of BUCK-BOOST Converters

    Institute of Scientific and Technical Information of China (English)

    殷立; 王顺强

    2012-01-01

    The inner intrinsic safety of BUCK-BOOST convert is analyzed by minimum ignition curve. The worst-case energy of BUCK-BOOST is calculated. Comparing with the minimum ignition curve, the intrinsic safety of BUCK-BOOST convert is implemented. Through calculation, the maximum load capacitor and inductance are obtained.%从最小点燃曲线角度分析BUCK-BOOST变换器内部本质安全性能,推算出BUCK-BOOST最恶劣情况下的能量,与火花点燃曲线相比较,得到本安输出的BUCK-BOOST变换器,并通过计算得出最大负载电容及负载电感。

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

    Directory of Open Access Journals (Sweden)

    P. Mašek

    2009-01-01

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

  6. Evaluation of Arm Processor-based Bionic Intelligent Controller for a Buck-boost Converte

    Directory of Open Access Journals (Sweden)

    M.V. Mini

    2015-07-01

    Full Text Available This study focuses on performance-comparison of different tuning methods for a PI controller applied to a buck-boost converter. Comparison between the controllers is made by analysis of design methodology implementation issues and empirically measured performance. Design of PI controller is based on frequency response of the converter. The optimization of PI controller is based on ant colony algorithm. Experimental results show that, tuning the PI controller using ACO algorithm gave better performance than the conventional algorithm. This is mainly due to the fact ACO is capable of reducing the overshoot without oscillation.

  7. Analysis and design of an adaptive multi-loop controlled two winding buck/boost regulator

    Science.gov (United States)

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

    1979-01-01

    Small signal low frequency linear average model is derived for a multi-loop controlled two-winding buck/boost converter employing average techniques and the describing function method. The model reveals that a well-designed multi-loop control can provide a second-order zero adaptive to output filter parameter changes due to component tolerances, temperature changes, aging, and the effect of duty cycle modulation. It also can provide stabilization effect by shifting the positive zero to the left-half S-plane. Design guidelines are formulated to optimize regulator-loop dependent characteristics.

  8. A New Approach for High Efficiency Buck-Boost DC/DC Converters Using Series Compensation

    Science.gov (United States)

    Itoh, Jun-Ichi; Fujii, Takashi

    This paper proposes a novel concept for non-isolated buck-boost DC/DC converter and control method. The proposed concept uses a series connection converter that only regulates the differential voltage between the input and output voltage. As a result, the power converter capacity is decreased. Moreover, the proposed circuit has advantages such as improved efficiency and losses reduction. The fundamental operation, control method, and design method of the proposed circuit are described in this paper. In addition, the validity of the proposed circuit is confirmed by carrying out simulations and experiments.

  9. Single stage buck-boost DC-AC neutral point clamped inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Andrew, A.;

    2012-01-01

    This paper proposes a new single stage buck-boost DC-AC neutral point clamped inverter topology which integrates the cascaded configurations of recently introduced inductor-capacitor-capacitor-transformer impedance source network (by Adamowicz) and classic NPC configuration. As a consequence...... windings thus preventing the core from saturation; lowers the voltage stresses and power losses of inverter switches and reduces the sizes of filtering devices and as well as obtains better output performance compared to the original two-level Z-source inverters. A phase disposition pulse width modulation...

  10. Analysis and design of an adaptive multi-loop controlled two winding buck/boost regulator

    Science.gov (United States)

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

    1979-01-01

    Small signal low frequency linear average model is derived for a multi-loop controlled two-winding buck/boost converter employing average techniques and the describing function method. The model reveals that a well-designed multi-loop control can provide a second-order zero adaptive to output filter parameter changes due to component tolerances, temperature changes, aging, and the effect of duty cycle modulation. It also can provide stabilization effect by shifting the positive zero to the left-half S-plane. Design guidelines are formulated to optimize regulator-loop dependent characteristics.

  11. Development and implementation of fuzzy logic using microcontroller for buck and boost DC-to-DC converter

    Science.gov (United States)

    Lorenzo, J., Jr.; Espiritu, J. C.; Mediavillo, J.; Dy, S. J.; Caldo, R. B.

    2017-06-01

    This paper aims to develop and implement a Sugeno-style fuzzy inference system using a microcontroller for buck and boost DC-to-DC converter. The buck converter circuit is given an input voltage range of 4-5V and expected to have an output voltage of 1.5V, while the boost converter has an input voltage range of 2-3V and expected to have an output voltage of 15V. A microcontroller will be used for the input values, PWM signal, which is supplied through the MOSFET. The constants in the program in the microcontroller were manipulated to acquire desired accurate output voltages wherein the concept of fuzzy logic was applied. The proponents achieved less than 2.5% tolerance in the buck converter and less than 5% in the boost converter.

  12. Computer Simulation Based Study of a Buck-Boost Circuit%基于计算机仿真的Buck-Boost电路研究

    Institute of Scientific and Technical Information of China (English)

    王利清; 魏学业; 温伟刚

    2004-01-01

    Buck-Boost电路中含有丰富的非线性现象.它工作过程中电路拓扑结构的循环切换导致了谐波、分叉和混沌等非线性行为.基于PSPICE仿真,研究了电流控制DC/DC Buck-Boost开关转换器中的倍周期现象.而且,建立了开关转换器的数学模型和叠代映射来解释这种非线性现象.基于MATLAB仿真,从叠代映射中得到了系统分叉图.%A buck-boost circuit is rich in nonlinear dynamics. Its operation is characterized by cyclic switching of circuit topologies, which gives rise to a variety of nonlinear, such as subharmonics, bifurcation and chaos. Based on PSPICE, the period-doubling phenomena exhibited by a current-programmed DC/DC buck-boost switching converter are studied. Furthermore, the system model and the iterative map of the converter are derived to explain the nonlinear phenomena. Based on MATLAB, the numerical simulation with this iterative map has led to the bifurcation diagram.

  13. Study on Nonlinear Phenomena in Buck-Boost Converter with Switched-Inductor Structure

    Directory of Open Access Journals (Sweden)

    Hongchen Liu

    2013-01-01

    Full Text Available The switched-inductor structure can be inserted into a traditional Buck-Boost converter to get a high voltage conversion ratio. Nonlinear phenomena may occur in this new converter, which might well lead the system to be unstable. In this paper, a discrete iterated mapping model is established when the new Buck-Boost converter is working at continuous conduction current-controlled mode. On the basis of the discrete model, the bifurcation diagrams and Poincare sections are drawn and then used to analyze the effects of the circuit parameters on the performances. It can be seen clearly that various kinds of nonlinear phenomena are easy to occur in this new converter, including period-doubling bifurcation, border collision bifurcation, tangent bifurcation, and intermittent chaos. Value range of the circuit parameters that may cause bifurcations and chaos are also discussed. Finally, the time-domain waveforms, phase portraits, and power spectrum are obtained by using Matlab/Simulink, which validates the theoretical analysis results.

  14. A New Transformerless Single-Phase Buck-Boost AC Voltage Regulator

    Directory of Open Access Journals (Sweden)

    YALCIN, F.

    2016-05-01

    Full Text Available Voltage regulation is one of the important goals for electrical sources and consumers. In this paper a new transformerless single-phase AC voltage regulator based on buck-boost converter topology is presented. The regulator circuit has a simple structure using only two bidirectional active switches, one inductor and one capacitor. A closed loop control system is implemented for the proposed regulator operation. A control law depending on the instantaneous values of the regulator's real input and desired output voltage is obtained and supports the PI controller. The control law allows the controller to obtain efficient pulse width modulation (PWM switching duty ratio for the desired output voltage when the input voltage has surges or fluctuations and the output load is changed. An experimental laboratory setup has been implemented for the proposed AC voltage regulator. The obtained results demonstrate that the proposed topology is capable of and efficient for both bucking and boosting the input AC voltage to a high quality output voltage with a low total harmonic distortion (THD for different input voltage and load conditions.

  15. High-accuracy current sensing circuit with current compensation technique for buck-boost converter

    Science.gov (United States)

    Rao, Yuan; Deng, Wan-Ling; Huang, Jun-Kai

    2015-03-01

    A novel on-chip current sensing circuit with current compensation technique suitable for buck-boost converter is presented in this article. The proposed technique can sense the full-range inductor current with high accuracy and high speed. It is mainly based on matched current mirror and does not require a large proportion of aspect ratio between the powerFET and the senseFET, thus it reduces the complexity of circuit design and the layout mismatch issue without decreasing the power efficiency. The circuit is fabricated with TSMC 0.25 µm 2P5M mixed-signal process. Simulation results show that the buck-boost converter can be operated at 200 kHz to 4 MHz switching frequency with an input voltage from 2.8 to 4.7 V. The output voltage is 3.6 V, and the maximum accuracy for both high and low side sensing current reaches 99% within the load current ranging from 200 to 600 mA.

  16. Current control of 6-phases 100kW interleaved buck/boost converter for railway application

    OpenAIRE

    2009-01-01

    The purpose of this paper is to present a 6-phases interleaved buck-boost converter of 100kW de-signed for a hybrid locomotive. The IGBT’s are working partially in continuous and discontinuous con-duction mode. Experiments show the effectiveness of the digital current control, current sharing and discontinuous-continuous transition with only one current sensor

  17. Estimation of Bidirectional Buck/boost DC/DC Converters with Electric Double-Layer Capacitors for Energy Storage Systems

    Science.gov (United States)

    Funabiki, Shigeyuki; Yamamoto, Masayoshi

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

  18. Power Flow Control of a Dual-Input Interleaved Buck/Boost Converter with Galvanic Isolation for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Zhang, Zhe; Knott, Arnold

    2015-01-01

    DC microgrids or nanogrids have attracted increasing research interest in recent years. Therefore, as a critical component, dc-dc converters with multiple inputs are required. In this paper, a dual-input interleaved buck/boost converter is proposed and its corresponding power flow control methods...

  19. Modeling and design of DCM Buck-Boost converter%DCM Buck-Boost变换器的建模与控制设计

    Institute of Scientific and Technical Information of China (English)

    方露; 党幼云; 康朋飞

    2015-01-01

    DC converter has the characteristics of nonlinear and multi modal .The model building of Buck-Boost converter is the key to design its closed-loop control system. The reliable output voltage and perfect dynamic characteristic of the Buck-Boost converter was greatly influenced by it. The AC small signal model is build on the basis of Buck-Boost converter's average switch model. Then get the transfer function of system. The voltage loop was also designed based on it. The design details for voltage loop were given and zero-pole compensation method from classic control theory was applied to the field of power electronics. The design of closed-loop control system and the model were verified through the analysis of the result of simulation in MATLAB software.%直流变换器一般具有非线性、多模态等特点。 Buck-Boost变换器的建模是其闭环控制设计的关键,对于Buck-Boost变换器输出可靠的电压和良好的动态响应特性具有非常重要的影响。本文是在Buck-Boost变换器断续模式的平均开关模型基础上建立其小信号交流模型,并推导出系统传递函数。在此基础上设计了电压闭环控制系统,进行了电压闭环参数设计的研究,实现了控制理论中零极点补偿法在电力电子中的应用。利用MATLAB软件进行仿真分析,验证了模型和闭环控制设计的正确性。

  20. Stability Analysis of the Buck-Boost Type Solar Array Regulator

    Science.gov (United States)

    Yang, Jeong-Hwan; Yoon, Seok-Teak; Park, Hee-Sung; Park, Sung-Woo; Koo, Ja-Chun; Jang, Jin-Baek; Lee, Sang-Kon

    2014-08-01

    The SAR (Solar Array Regulator) is different from a general DC-DC Converter. The input of the SAR is connected to the solar array and the output is connected to the battery. So, the output voltage of the SAR is constant and the input voltage of the SAR is variable. And the solar array current which is the SAR input current is variable according to the solar array voltage. Therefore, the SAR is influenced by the electrical characteristic of the solar array. For these reasons, a small signal model for a general DC-DC converter cannot be applied to the SAR for the stability analysis. In this paper, the small signal model of the BUCK-BOOST type SAR (BBSAR) is introduced and its transfer functions are induced. Using small signal transfer functions, the stability analysis is performed and its results are compared to the simulation result.

  1. Advanced Energy Conversion System Using Sinusoidal Voltage Tracking Buck-Boost Converter Cascaded Polarity Changing Inverter

    Science.gov (United States)

    Ahmed, Nabil A.

    2011-06-01

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

  2. Closed-loop analysis and control of a non-inverting buck-boost converter

    Science.gov (United States)

    Chen, Zengshi; Hu, Jiangang; Gao, Wenzhong

    2010-11-01

    In this article, a cascade controller is designed and analysed for a non-inverting buck-boost converter. The fast inner current loop uses sliding mode control. The slow outer voltage loop uses the proportional-integral (PI) control. Stability analysis and selection of PI gains are based on the nonlinear closed-loop error dynamics incorporating both the inner and outer loop controllers. The closed-loop system is proven to have a nonminimum phase structure. The voltage transient due to step changes of input voltage or resistance is predictable. The operating range of the reference voltage is discussed. The controller is validated by a simulation circuit. The simulation results show that the reference output voltage is well-tracked under system uncertainties or disturbances, confirming the validity of the proposed controller.

  3. The Simulation Research of Buck-Boost Converter%Buck-Boost变化器的仿真分析

    Institute of Scientific and Technical Information of China (English)

    李雪莉

    2010-01-01

    PSpice是一款功能强大的电路仿真软件,仿真结果十分接近电路的真实状态.应用PSpice对Buck-Boost变换器的全部工作过程进行了仿真与分析,Buck-Boost电路的工作过程包括电路启动时的瞬态工作过程和稳态工作过程.对电路中储能元件的各种工作状态进行了分析,给出了大量直观的仿真波形,从而更进一步了解了Buck-Boost变换器.

  4. Analysis the application of quadratic Buck-Boost converter in photovoltaic energy-conversion system%二次型 Buck-Boost 变换器在光伏系统的应用分析

    Institute of Scientific and Technical Information of China (English)

    修瑞仙; 张士宇

    2015-01-01

    This paper introduced the working state of single switch quadratic Buck-Boost converter in continuous-discontinuous conduction mode, researched the photovoltaic cells model and maximum power tracking theory,through the simulation analysis,obtained the quadratic CDCM Buck-Boost converter applied to photovoltaic power generation system could realize the maximum power point tracking and wide range maximum power tracking,and was not affected by load change.%介绍了单开关二次型Buck-Boost变换器在连续—断续导电模式下的工作状态,研究了光伏电池模型及最大功率跟踪原理,通过仿真分析,得出将二次型CDCM Buck-Boost变换器应用到光伏发电系统中可实现最大功率点跟踪与宽范围的最大功率跟踪,并且不受负载变化影响。

  5. GENERAL: Mode shift and stability control of a current mode controlled buck-boost converter operating in discontinuous conduction mode with ramp compensation

    Science.gov (United States)

    Bao, Bo-Cheng; Xu, Jian-Ping; Liu, Zhong

    2009-11-01

    By establishing the discrete iterative mapping model of a current mode controlled buck-boost converter, this paper studies the mechanism of mode shift and stability control of the buck-boost converter operating in discontinuous conduction mode with a ramp compensation current. With the bifurcation diagram, Lyapunov exponent spectrum, time-domain waveform and parameter space map, the performance of the buck-boost converter circuit utilizing a compensating ramp current has been analysed. The obtained results indicate that the system trajectory is weakly chaotic and strongly intermittent under discontinuous conduction mode. By using ramp compensation, the buck-boost converter can shift from discontinuous conduction mode to continuous conduction mode, and effectively operates in the stable period-one region.

  6. Mode shift and stability control of a current mode controlled buck-boost converter operating in discontinuous conduction mode with ramp compensation

    Institute of Scientific and Technical Information of China (English)

    Bao Bo-Cheng; Xu Jian-Ping; Liu Zhong

    2009-01-01

    By establishing the discrete iterative mapping model of a current mode controlled buck-boost converter, this paper studies the mechanism of mode shift and stability control of the buck-boost converter operating in discontinuous conduction mode with a ramp compensation current. With the bifurcation diagram, Lyapunov exponent spectrum, timedomain waveform and parameter space map, the performance of the buck-boost converter circuit utilizing a compensating ramp current has been analysed. The obtained results indicate that the system trajectory is weakly chaotic and strongly intermittent under discontinuous conduction mode. By using ramp compensation, the buck-boost converter can shift from discontinuous conduction mode to continuous conduction mode, and effectively operates in the stable period-one region.

  7. π型Buck-Boost交流变换器%π Type Buck-Boost AC/AC Converter

    Institute of Scientific and Technical Information of China (English)

    张友军; 翁振明; 王阿敏; 项家希

    2012-01-01

    提出一种对称结构π型Buck-Boost交流变换器及其变结构控制策略.该变换器由Buck交流单元和Boost交流单元组成,与级联式两级电路相比,省去前级LC输出滤波器,简化了电路结构.根据前、后单元的工作与否,π型交流变换器存在4种工作模式:Buck模式、Boost模式、直通模式和Buck -Boost模式.通过等效改变电路结构,变结构控制策略使得π型Buck-Boost交流变换器只有3种工作模式:Buck模式、Boost模式和直通模式.π型Buck -Boost交流变换器虽然具有两个独立的控制对象、采用两级占空比调制,但实际上最多只有一级功率变换,且存在直接功率传递通路,适用于稳压或调压应用场合.

  8. Modeling and dynamics analysis of the fractional-order Buck-Boost converter in continuous conduction mode

    Institute of Scientific and Technical Information of China (English)

    Yang Ning-Ning; Liu Chong-Xin; Wu Chao-Jun

    2012-01-01

    In this paper,the fractional-order mathematical model and the fractional-order state-space averaging model of the Buck-Boost converter in continuous conduction mode (CCM) are established based on the fractional calculus and the Adomian decomposition method.Some dynamical properties of the current-mode controlled fractional-order BuckBoost converter are analysed.The simulation is accomplished by using SIMULINK.Numerical simulations are presented to verify the analytical results and we find that bifurcation points will be moved backward as α and β vary.At the same time,the simulation results show that the converter goes through different routes to chaos.

  9. Modeling and Characteristics Analysis for a Buck-Boost Converter in Pseudo-Continuous Conduction Mode Based on Fractional Calculus

    Directory of Open Access Journals (Sweden)

    Ningning Yang

    2016-01-01

    Full Text Available In recent days, fractional calculus (FC has been accepted as a novel modeling tool that can extend the descriptive power of the traditional calculus. Fractional-order descriptiveness can increase the flexibility and degrees of freedom of the model by means of fractional parameters. Based on the fact that real capacitors and inductors are “intrinsic” fractional order, fractional calculus is introduced into the modeling process to establish a fractional-order state-space averaging model of the Buck-Boost converter in pseudo-continuous conduction mode (PCCM. Orders of the model are considered as extra parameters, and these parameters have significant influences on the performance of the model. The inductor current, the inductor current ripple, the amplitude of the output voltage, and the transfer functions of the fractional-order model are all related to orders. The contrast simulation experiments are conducted to investigate the performance of integer-order and fractional-order Buck-Boost converters in PCCM. Results of numerical and circuit simulations demonstrate that the proposed theoretical analysis is effective; the fractional-order model of the Buck-Boost converter in PCCM has certain theoretical and practical significance for modeling and performance analysis of other electrical or electronic equipment.

  10. Adaptive Control of Fast-Scale Bifurcation in Peak Current Controlled Buck-Boost Inverter via One-Cycle Compensation

    Science.gov (United States)

    Zhang, Hao; Dong, Shuai; Guan, Weimin; Yi, Chuanzhi; He, Bo

    In this paper, one-cycle compensation (OCC) method is proposed to realize adaptive control of fast-scale bifurcation in the peak current controlled buck-boost inverter because the proposed control method can adjust the slope of the integrator’s output voltage automatically through extracting a sinusoidal signal from the absolute value of the reference voltage. In order to reveal their underlying mechanisms of fast-scale bifurcations, a modified averaged model which can capture the sample-and-hold effect is derived in detail to describe the fast-scale dynamics of the buck-boost inverter. Based on the proposed model, a theoretical analysis is performed to identify both the fast-scale period-doubling bifurcation and the fast-scale Hopf one by judging in what way the poles loci move. It has been shown that the OCC method can be used not only to discover the unknown dynamical behaviors (i.e. fast-scale Hopf bifurcation), but also to enlarge the stable region in peak current controlled buck-boost inverter. In addition, the critical bifurcation angles and the parameter behavior boundary are given to verify the effectiveness of the adaptive bifurcation control method. Finally, PSpice circuit experiments are performed to verify the above theoretical and numerical results.

  11. 零纹波输入电流Buck-Boost变换器%Zero Rippled Input Current Buck-Boost Converter

    Institute of Scientific and Technical Information of China (English)

    陆治国; 林贤贞; 胡红琼; 邓文东

    2008-01-01

    针对传统Buck-Boost输入输出电流断续的缺点,提出一种基于独立电感零纹波输入电流和输出电流连续的Buck-Boost变换器,详细分析了变换器的稳态工作原理.采用状态空间平均法,建立了变换器动态小信号模型,给出了小信号特征Matlab仿真波形.并对其进行交错并联优化,最后Saber电路仿真证明了理论分析的正确性.

  12. Buck-Boost/Forward Hybrid Converter for PV Energy Conversion Applications

    Directory of Open Access Journals (Sweden)

    Sheng-Yu Tseng

    2014-01-01

    Full Text Available This paper presents a charger and LED lighting (discharger hybrid system with a PV array as its power source for electronic sign indicator applications. The charger adopts buck-boost converter which is operated in constant current mode to charge lead-acid battery and with the perturb and observe method to extract maximum power of PV arrays. Their control algorithms are implemented by microcontroller. Moreover, forward converter with active clamp circuit is operated in voltage regulation condition to drive LED for electronic sign applications. To simplify the circuit structure of the proposed hybrid converter, switches of two converters are integrated with the switch integration technique. With this approach, the proposed hybrid converter has several merits, which are less component counts, lighter weight, smaller size, and higher conversion efficiency. Finally, a prototype of LED driving system under output voltage of 10 V and output power of 20 W has been implemented to verify its feasibility. It is suitable for the electronic sign indicator applications.

  13. Start Up Current Control of Buck-Boost Convertor-Fed Serial DC Motor

    Directory of Open Access Journals (Sweden)

    Yusuf SÖNMEZ

    2009-02-01

    Full Text Available Generally, DC motors are given preference for industrial applications such as electric locomotives, cranes, goods lifts. Because of they have high starting moment; they initially start with high current. This high start-up current must be decreased since it may damage windings of the motor and increases power consumption. It could be controlled by an appropriate driver system and controller. The nature of fuzzy logic control has adaptive characteristics that can achieve robust response to a system with uncertainty, parameter variation, and load disturbance. In this paper, fuzzy logic based control of start-up current of a Buck-Boost Converter fed serial DC motor is examined through computer simulation. In order to see the advantages of fuzzy logic control, classical PI control has applied to the same motor, under same circumstances and has been compared. C++ Builder software has been used for the simulation. According to the simulation results, plainly, fuzzy logic control has stronger responses than classical PI control and uses lower current at starting moment.

  14. A Comparison between Buck-Boost Inverter with and without Buffer Inductor

    Directory of Open Access Journals (Sweden)

    Purwadi Agus Darwito

    2012-05-01

    Full Text Available The electric vehicle inverter requires an induction motor drive with a high output of voltage and current to reduce the number of batteries used and in turn reduce the vehicle’s weight. In this paper compared two single Phase BuckBoost Inverter (SPBBI, that is between the SPBBI conventional topology with SPBBI new topology uses a buffer inductor. The results of comparison are expected that the new inverter topology can strengthen the voltage greater than the conventional inverter topology. The inverter’s components of capacitor and inductor were reconfigured. The circuit was simulated for various carrier and signal frequencies with various load. The simulation results of the proposed topology compared with the simulation results of conventional topologies commonly used in a variety of frequency and load values. It is shown that the output voltage and current can be strengthened significantly, with a value of more than five times of the output voltage compared to the conventional inverter. The new inverter topology is useful to be implemented for the electric vehicle.

  15. Half Load-Cycle Worked Dual Buck-Boost Single-Stage Inverter%半周控制双Buck-Boost单级逆变器

    Institute of Scientific and Technical Information of China (English)

    嵇保健; 洪峰

    2011-01-01

    本文提出了一种新颖的双Buck-Boost单级逆变器。单级式逆变器相比传统的两级式逆变器,拓扑结构大大简化,减小了体积重量,降低了损耗,在中小功率场合中的应用具有明显的优势。同时传统单级逆变器不能直接实现升压逆变,在输入母线电压较低时必须增加前级升压电路。针对以上情况,本文通过将两个Buck-Boost电路采用输入串联、输出并联的方式组合,得到一种新型的双Buck-Boost逆变器,并采用半周工作方式使其正常可靠工作,可实现单级直接升压逆变。文中对该电路的工作原理和控制策略进行了详细的分析。仿真和实验验证了新型电路的可行性。该电路在输入母线电压低于输出电压的宽电压范围内均能正常逆变,并取得了较好的波形质量和较高的变换效率。%A novel half load-cycle worked dual Buck-Boost single-stage inverter is presented in this paper.Compared with the traditional two-stage inverter,the single-stage inverter is smaller and lighter due to the structure is greatly simplified as well as the circuit components are reduced a lot.Direct boost DC-AC converter can not be realized by most traditional inverter,so one DC-DC converter has to be added in the front of traditional inverter when input bus voltage is low.In order to obtain one single-stage inverter which can make direct boost inverter come true,two Buck-Boost topologies are combined which are series-wound in input side and parallel connected in output side.Special half load-cycle control mode is used in this new inverter.No matter the input bus voltage is higher or lower than the output voltage,the new inverter works normally and reliably and the output waveform is good,the converter efficiency is high at the same time.Simulation and Experiment verifies those analysis.

  16. A Positive Buck Boost Converter with Mode Select Circuit and Feed Forward Techniques Using Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Latha. S. C

    2014-11-01

    Full Text Available The portable devices development of semiconductor manufacturing technology, conversion efficiency, power consumption, and the size of devices have become the most important design criteria of switching power converters. For portable applications better conveniences extension of battery life and improves the conversion efficiency of power converters .It is essential to develop accurate switching power converters, which can reduce more wasted power energy. The proposed topology can achieve faster transient responses when the supply voltages are changed for the converter by making use of the feed forward network .With mode select circuit the conduction & switching losses are reduced the positive buck–boost converter operate in buck, buck–boost, or boost converter. By adding feed-forward techniques, the proposed converter can improve transient response when the supply voltages are changed. The designing, modeling & experimental results were verified in MATLAB/ Simulink. The fuzzy logic controller is used as controller.

  17. 适用于低电压输出的单级式无桥buck?boost PFC变换器%Single Stage Bridgeless Buck?Boost PFC Converter for Low Output Voltage Application

    Institute of Scientific and Technical Information of China (English)

    赵犇; 马瑞卿

    2015-01-01

    An additional DC?DC converter is needed for traditional boost power factor correction ( PFC) converter to obtain low output voltage. When using buck type topology, the distortion of input current is large because no pow?er is transferred to output when gird voltage is lower than output voltage. Thus, the buck?boost type topology be?comes priority in the low output voltage application. Compared with the classic cascaded buck?boost PFC converter, the proposed single stage bridgeless buck?boost topology has lower semiconductors counts, and lower devices counts in the conduction loop which means less conduction losses. The tapped inductor is employed to achieve more attenu?ation. Thus, the proposed topology suits the low output voltage application very well. The One Cycle Control ( OCC) is adopted to achieve good dynamic performance and the elimination of multiplier can simplify the control circuit and reduce the cost. The simulated results and their analysis show preliminarily that:(1) the proposed topology is feasible and has the merits of simple structure and less conduction losses; ( 2 ) the power factor correction using OCC is reliable and has the advantages of low current distortion and high power factor.%传统的boost型功率因数校正变换器需要额外1级DC?DC变换器才能实现低电压输出,而buck型拓扑由于在电网电压低于输出电压时没有输入电流而导致电流畸变很大,因此buck?boost型拓扑就成为在低电压输出场合实现单级式功率因数校正的优先选择. 相较于经典的级联式buck?boost功率因数校正变换器,文中所提出的单级式无桥buck?boost拓扑所需的半导体器件数量更少,且导通回路中的功率器件个数也大大减小,从而可以降低导通损耗;加上引入了耦合电感提高了电压衰减率,因此特别适合低电压输出场合;采用了单周期控制作为功率因数校正的控制方法,具有更好的动态性能,而且电路实现中无需乘法

  18. Active battery charge equalization with voltage controlled vertical buck-boost switching cells%电压控制Buck-Boost电池充电均衡器

    Institute of Scientific and Technical Information of China (English)

    谢莉; 蒋伟

    2015-01-01

    本文研究了储能设备的均衡充电方法。采用垂直 Buck-Boost 电路作为均衡器的基本交换单元。在不同的负载条件下,用状态空间平均法和小信号分析法获得对应的开关单元模型。通过电压控制均衡方案,利用电压环补偿设备端电压,电流内环使得电荷定向移动。实验结果表明,所提出的均衡器能实现电荷最快移动并能有效地收敛到零电压差,本地控制器能快速、准确地跟踪参考值。%This paper investigates the active charge equalization method for energy storage devices. The vertical buck-boost circuit is used as the basic switching cell of this equalizer. By applying state-space averaging and small signal analysis, the model of the switching cell is obtained under different load condition. A voltage controlled equalization scheme is presented, which is featured with voltage loop to equalize the terminal voltage and inner current loop for charge shuttling. The simulation and experimental results indicate that the proposed equalizer can effectively converge to zero voltage difference condition by offering a maximized charge shuttling effort, and the local controller can react fast and precisely to the reference command.

  19. AC/DC Buck-Boost PFC变换器滑模变结构及PI调节器综合控制%Sliding-Mode Variable-Structure and PI Control AC/DC Buck-Boost PFC Converter

    Institute of Scientific and Technical Information of China (English)

    马化盛; 张波; 郑健超; 梁少毅

    2004-01-01

    以AC/DC Buck-Boost PFC变换器为主拓扑,提出滑模变结构电流内环控制与PI调节器电压外环控制相结合的综合控制系统,以实现变换器高性能的单位功率因数校正.仿真和实验研究结果表明,这种控制系统设计兼有滑模控制动态性能、鲁棒性好与PI调节器稳定性好的优点.

  20. Design of isolated Buck-Boost DC/DC converter%Buck-Boost隔离直流转换器设计

    Institute of Scientific and Technical Information of China (English)

    王雪丹; 李文鹤

    2012-01-01

    Buck-Boost隔离直流转换器宽范围输入电压的条件下,分析了典型的全桥Boost转换器拓扑结构,由于存在的谐振电感包括漏电感,全桥Boost转换器只能采用双边沿调制.该转换器采用UC3895作为控制器,对全桥单元采用移相转换控制的方式,为了提高全桥Boost转换器系统的可靠性和效率,采用三模式两频率控制方式,在输入宽范围电压的情况下,最高500 V输入,360 V输出.在此采用Matlab软件进行仿真,实验结果表明输入电压平均效率范围是96.2%,最高效率能达到97.5%.%The topology structure of a typical FB Boost converter was analyzed under the condition of wide range input voltage of isolated Buck-Boost DC/DC converter. The FB Boost converter can only adopt two-edge-modulation (TEM) due to the resonant induction including the leakage induction. The converter takes UC3895 available in market as the controller to control the FB-cell with phase-shifted. In order to improve the reliability and efficiency of the FB-Boost converter, a three-mode dual-frequency control mode was used. The maximum input voltage is 500 V and the output'is 360 V in the case of the wide range input voltage. The Matlab software was adopted for simulation. The result shows the the average efficiency range of the input-voltage is 96. 2% and the highest efficiency can reach to 97. 3%.

  1. 一种非反相Buck-Boost功率变换器的调制方法研究%Research on Modulation Method for Non-inverting Buck-Boost Power Converter

    Institute of Scientific and Technical Information of China (English)

    徐坤; 杨宇; 吴春华; 许富强

    2011-01-01

    针对功率变换器现有调制方法的不足,提出了一种用于非反相Buck-Boost功率变换器的调制方法,结合脉冲宽度调制和脉冲频率调制,使该功率变换器平滑地在Buck、Buck-Boost、Boost三种模式之间切换,从而在输入电压低于、高于或近似等于输出电压给定值的情况下,使输出电压稳定在给定电压.试验结果验证了该算法的可行性和有效性.%Aiming at the drawbacks of modulation method for power converter, a modulation method which combines pulse width modulation (PWM) with pulse frequency modulation (PFM) for the non-inverting buck-boost converter is proposed in the paper.The power converter can switch smoothly among buck working mode, buck boost working mode and boost working mode in order to regulate the output voltage to the desired output voltage regardless of that the input voltage is less than, greater than or equal to the desired output voltage.The experimental results verify the feasibility and efficiency of the proposed algorithm.

  2. Pengaturan Kecepatan Motor DC pada Mobil Listrik Menggunakan Bidirectional Buck-Boost Cascade Converter berbasis Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Muhammad Taufiq Ramadhan

    2015-03-01

    Full Text Available Penggunaan mobil listrik secara umum terkendala pada beban, kecepatan aktual, serta efisiensi energi. Pemanfaatan Fuzzy Logic Controller untuk pengaturan kecepatan motor DC pada mobil listrik diperlukan untuk meraih kecepatan aktual yang lebih presisi  sehingga diperoleh efisiensi energi. Selain itu perlu juga  menggunakan Bidirectional Buck-Boost Cascade Converter untuk pengaturan motor DC secara bidirectional, yakni pengaturan saat motoring dan saat pengereman regeneratif (regenerative braking. Hal ini berdasar pada energi yang terbuang percuma, baik itu rugi elektris maupun rugi mekanis saat pengereman.

  3. A Buck-Boost Converter Modified to Utilize 600V GaN Power Devices in a PV Application Requiring 1200V Devices

    OpenAIRE

    2015-01-01

    This paper presents a buck-boost converter which is modified to utilize new 600 V gallium nitride (GaN) power semiconductor devices in an application requiring 1200 V devices. The presented buck-boost converter is used as a part of a dc/dc stage in an all-GaN photovoltaic (PV) inverter and it provides a negative voltage for the 3-level neutral-point-clamped (NPC) PWM inverter which is connected to the utility grid. Since in this application the transistor and the diode of ...

  4. A Comparative study of Analog and digital Controller On DC/DC Buck-Boost Converter Four Switch for Mobile Device Applications

    Directory of Open Access Journals (Sweden)

    Benlafkih Abdessamad

    2013-01-01

    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.

  5. Modelling and Control Design of a Dual Buck-Boost AC/DC Converter Used in the DC Nano-Grid

    DEFF Research Database (Denmark)

    Wu, Weimin; Liu, Yuan; Wang, Houqing;

    2016-01-01

    like the low voltage AC power system. In this paper, a dual Buck-Boost AC/DC converter for use in the united grounding configuration based DC Nano-grid with three terminal outputs is proposed. It will be much easy to construct an efficient DC Nano-grid based on the existing low AC power system by using......Due to widely used DC characterized loads and more distributed power generation sources, the DC Nano-grid becomes more and more popular and seen as an alternative to the AC-grid in future. For the safety considerations, the DC Nano-grid should provide reliable grounding for the residential loads...... the proposed converter. The working principle of this converter and the system modeling are presented in detail. Simulations are carried out to verify the theoretical analysis....

  6. Buck-boost converter for simultaneous semi-active vibration control and energy harvesting for electromagnetic regenerative shock absorber

    Science.gov (United States)

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

    2014-04-01

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

  7. Analysis of Fast-Scale Bifurcation in Peak Current Controlled Buck-Boost Inverter Based on Unified Averaged Model

    Science.gov (United States)

    Zhang, Hao; Dong, Shuai; Guan, Weimin; Liu, Ye

    In this paper, a unified averaged modeling method is proposed to investigate the fast-scale period-doubling bifurcation of a full-bridge integrated buck-boost inverter with peak current control. In order to increase the resolution of the conventional classic averaged model to half the switching frequency, sample-and-hold effect of inductor current is absorbed into the averaged model, i.e. the proposed unified averaged model can capture the high-frequency dynamical characteristics of the buck-boost inverter, which is both an extension and a modification of conventional averaged model. Based on the unified mode, fast-scale bifurcation is identified, and the corresponding bifurcation point is predicted with the help of the locus movement of all the poles, and their underlying mechanisms are revealed. Detailed analysis shows that the occurrence of high-frequency oscillation means fast-scale bifurcation, while the occurrence of low-frequency oscillation leads to slow-scale bifurcation. Finally, it is demonstrated that the unified averaged model can provide not only a general method to investigate both the slow- and fast-scale bifurcations in a unified framework but also a quite straightforward design-oriented method which can be directly applicable.

  8. 两开关伪连续导电模式Buck.Boost功率因数校正变换器%Two-switch Pseudo Continuous Conduction Mode Buck-Boost Power Factor Correction Converter

    Institute of Scientific and Technical Information of China (English)

    张斐; 许建平; 杨平; 陈章勇

    2012-01-01

    A novel two-switch Buck-Boost power factor correction (PFC) converter operating in pseudo continuous conduction mode (PCCM) and its corresponding control strategy were proposed in this paper. The two-switch PCCM Buck-Boost PFC topology provides an additional degree of control freedom to realize PFC control, which can offer significant performance improvements over single-switch Buck-Boost PFC converters or two-switch Buck-Boost PFC converters in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The additional degree of control freedom introduced by inductor current freewheeling stage helps to achieve unity power factor control. Besides, inductor current ripple of the two-switch PCCM Buck-Boost PFC converter, which is lower than that of the two-switch DCM Buck-Boost PFC converter, can be obtained. Analysis, simulation and experiment results of the two-switch PCCM Buck-Boost PFC converter were presented. The experiment results show that the dynamic response of the two-switch PCCM Buck-Boost PFC converter is significantly faster than that of the two-switch CCM and DCM Buck-Boost PFC converter.%提出两开关伪连续导电模式(pseudocontinuousconductionmode,PCCM)Buck-Boost功率因数校jE(powerfactorcorrection,PFC)变换器及其控制策略。利用两开关PCCMBuck.BoostPFC变换器电感惯性模态所提供的一个额外控制自由度,可实现单位功率因数控制,并明显改善传统单开关Buck-BoostPFC变换器、两开关连续导电模式(continuousconductionmode,CCM)Buck.BoostPFC变换器和两开关不连续导电模式(discontinuousconductionmode,DCM)Buck-BoostPFC变换器的性能。与两开关DCMBuck.BoostPFC变换器相比,两开关PCCMBuck.BoostPFC变换器减小了电感电流纹波。仿真与实验结果表明,两开关PCCMBuck-BoostPFC变换器的负载动态响应速度明显快于传统的两开关CCM和DCMBuck-BoostPFC变换器。

  9. Study of Bifurcation and Chaos in the Current-Mode Controlled Buck-Boost DC-DC Converter (I) --Modeling and Simulation%Buck-BOOst DC-DC变换器中分叉与混沌问题的研究(Ⅰ)--建模与仿真

    Institute of Scientific and Technical Information of China (English)

    吴捷; 刘明建; 杨苹

    2002-01-01

    This paper studies the bifurcation and chaos in current-mode controlled Buck-Boost converter. The discrete model for Buck-Boost converter in continuous conduction mode (CCM) is derived. The bifurcation and chaos phenomena of Buck-Boost converter have been investigated with input voltage E, reference current Iref, resistor R, inductor L and capacitor C as bifurcation parameters.%研究了电流控制型Buck-Boost变换器中的分叉与混沌问题.首先,对连续模式下的Buck-Boost变换器建立了离散数学模型,在此基础上,在输入电压E、参考电流Iref、电阻R、电感L和电容C等分叉参数作用下,通过数值方法对Buck-Boost变换器中的分叉与混沌进行了详细的仿真研究.仿真研究结果表明:Buck-Boost变换器具有丰富的非线性行为--分叉与混沌,随着各个分叉参数的变化系统会遵循倍周期分叉的规律走向混沌.

  10. Analyses of Buck-Boost Converter Based on the Principle of Volt-second Balance%基于伏秒平衡原理的Buck-Boost变换器分析

    Institute of Scientific and Technical Information of China (English)

    王学梅; 易根云; 丘东元; 张波

    2012-01-01

    针对现有"电力电子技术"教材中普遍存在的对Buck-Boost变换器的分析不完整等问题,本文基于伏秒平衡原理对Buck-Boost变换器进行了全面分析,推导出变换器全范围的输入输出电压关系,电流连续模式(CCM)和断续模式(DCM)的临界工作条件以及电路各参数对电流纹波和电压纹波的影响等。本文一方面有助于更全面深入地理解Buck-Boost变换器的工作原理及特性,另一方面有助于DC-DC变换器分析方法的统一,具有一定的教学指导意义。%There are some incomplete analyses of buck-boost converters in current materials of power electronics. Based on the principle of volt-second balance, this paper analyzes the buck-boost converter comprehensively. Next, the ratio of input and output voltage in full range is derived, and the critical working conditions in continuous conduction mode and discontinuous conduction mode are analyzed. Last, the effects of circuit parameters on current and voltage rip- ple are illustrated. On the one hand, this paper can help to understand thoroughly the operating principle of buck-boost converter, and on the other hand, it also can help to analyses DC-DC converters uniformly, which has certain signifi- cance in the teachings of power electronics.

  11. An Integrated Buck-Boost LLC Cascaded Converter With Wide Input Voltage Range%一种具有宽输入电压范围的集成Buck-Boost LLC级联变换器

    Institute of Scientific and Technical Information of China (English)

    孙孝峰; 仇江峰; 栗晓华; 骆志伟

    2016-01-01

    研究一种集成Buck-Boost LLC(integrated Buck-Boost LLC,IBBLLC)变换器。该变换器适用于宽输入电压范围场合的应用,通过开关管的共用变换器减少了开关管数量。通过采用PWM+Phase-Shift控制,使得原边各个开关管在全输入电压和全负载范围内均能够实现零电压开通(zero voltage switching,ZVS)。文中首先介绍变换器的拓扑结构及直流增益。其次详细分析变换器的工作模式及前级电感Lb对变换器性能的影响,为变换器参数的选取提供了理论依据。此外,研究变换器的ZVS特性,给出变换器能够实现 ZVS 的工作区域。最后搭建一台200~450 V 输入、14 V/80 A 输出的实验样机,实验结果验证了理论分析的正确性及方案的可行性。%An integrated Buck-Boost LLC (IBBLLC) converter which is a good candidate for wide input voltage applications was researched. By sharing the switches, the amount of the switches is reduced. In order to make all primary switches realize ZVS under whole input voltage range and load conditions, PWM+Phase-Shift control strategy is employed in this converter. Firstly, the topology and DC gain of the converter was introduced. Then the operations modes and the influence of inductor was introduced which can provide theoretical foundation for the parameters selection. Besides, the ZVS conditions were analyzed and the ZVS operation area of the converter was given. Finally, a prototype with 200~450V input voltage, 14V output voltage and 80A output current was established to verify the correctness of the theoretical analysis and the feasibility of the control strategy.

  12. A Ripple Suppression with Staggered Parallel Buck/Boost Converter Light Load Efficiency Research%一种带纹波抑制的交错并联Buck/Boost变换器轻载效率研究

    Institute of Scientific and Technical Information of China (English)

    刘悦新; 王磊

    2016-01-01

    非隔离型交错并联双向Buck/Boost变换器普遍存在轻载效率低的难题。以多相交错并联Buck/Boost变换器Boost模式为研究对象,分别对其工作在DCM和CCM模式下的功率损耗进行综合性分析研究。根据变换器轻载运行时降低频率可以提高效率的原则,提出最优化调频原则,对其不同负载下开关频率进行调整,以达到提高效率的目的。针对降低频率会带来纹波恶化的缺陷,将磁集成技术应用到交错并联双向Buck/Boost变换器,有效改善通道电感电流纹波及输出电压纹波,并给出磁集成后滤波电容优化设计原则,以最大程度减小损耗,提高轻载效率。最后通过仿真和实验验证了理论分析的正确性,为交错并联双向Buck/Boost 变换器轻载效率优化提供了新的理论依据,推动了全负载高效率双向Buck/Boost变换器的设计实现。%The non-isolated interleaving bi-directional Buck-Boost converter is faced with a widespread problem of low underloading efficiency. The Boost model of the multi-phase interleaving Buck/Boost converter is adopted as the research object in this paper, and a comprehensive analysis of power loss is conducted under the DCM and CCM model. According to the principle that efficiency can be increased through reduced frequency during underloading operation of the transformer, and the principle of optimized frequency modulation is put forward to adjust the switching frequency under different loads so as to realize the goal of increasing efficiency. Concerning the defect of worsening ripples caused by reduced frequency, the magnetic integration technique is applied to the interleaving bi-directional Buck/Boost converter to efficiently improve the channel’s inductive current ripples and the output voltage ripples. Besides, the filter capacitor optimized design principle after magnetic integration is given at an attempt to minimize loss and increase underloading

  13. A Buck-Boost Converter Modified to Utilize 600V GaN Power Devices in a PV Application Requiring 1200V Devices

    Directory of Open Access Journals (Sweden)

    SRDIC, S.

    2015-08-01

    Full Text Available This paper presents a buck-boost converter which is modified to utilize new 600 V gallium nitride (GaN power semiconductor devices in an application requiring 1200 V devices. The presented buck-boost converter is used as a part of a dc/dc stage in an all-GaN photovoltaic (PV inverter and it provides a negative voltage for the 3-level neutral-point-clamped (NPC PWM inverter which is connected to the utility grid. Since in this application the transistor and the diode of the buck-boost converter need to block the sum of the PV string voltage (which is normally in the range from 150 to 350 V and the dc bus voltage (which is in the order of 400 V, the 1200 V devices or series connection of 600 V devices need to be employed. Currently, 1200 V GaN power semiconductor devices are not commercially available. Therefore, the standard buck-boost converter is modified to enable the use of 600 V GaN devices in this particular application. Based on the proposed converter topology, a PSpice simulation model and a 600 W converter prototype were developed. Both simulation and experimental results show successful operation of the converter.

  14. Output voltage ripple control two-switch PCCM Buck-Boost PFC converter%输出电压纹波控制两开关PCCM Buck-Boost PFC变换器

    Institute of Scientific and Technical Information of China (English)

    张斐; 许建平; 董政; 舒立三

    2013-01-01

    研究了两开关伪连续导电模式(pseudo continuous conduction mode,PCCM) Buck-Boost功率因数校正(power factor correction,PFC)变换器的工作原理,为了简化两开关PCCM Buck-Boost PFC变换器的控制器设计,在分析单相PFC变换器输出电压纹波的基础上,提出了输出电压纹波反馈控制算法.该算法采样PFC变换器的输出电压,通过计算得到输出电压纹波值来实时调整电流控制环的补偿系数,无需增加额外的硬件电路,利用数字信号处理器的编程方式即可实现.仿真与实验结果表明,当负载功率发生大范围变化时所设计的系统具有快速动态响应能力.

  15. 基于Buck-Boost变换器的T-S模糊建模和仿真研究%T-S fuzzy modeling and simulation of Buck-Boost converter

    Institute of Scientific and Technical Information of China (English)

    王艳; 吴正成; 纪志成

    2008-01-01

    根据Buck-Booat变换器的工作原理及其非线性特征,在电感电流连续导通模式和断续导通模式下,分别对Buck-Boost 电路构建T-S模糊模型,在断续导通模式下,引入切换函数,统一了两种模式下电路状态方程和T-S模糊模型.仿真结果表明,Buck-Boost变换器经T-S建模后,输出电压平均值和电感电流的平均值的误差均在2%以内,符合实际应用的要求.T-S模糊建模的有效性和可行性得到验证.

  16. Study on the dynamic performance of a novel buck-boost matrix converter based on double-loop control strategy

    Science.gov (United States)

    Li, Qing; Zhang, Xiao-ping; Chen, Qi

    2011-12-01

    The dynamic performance of a novel Buck-Boost matrix converter (BBMC) based on double-loop control strategy is put forward in this paper. The fundamental principle of BBMC has been elaborated and the method of the double-loop control strategy has been built with Matlab, and then the dynamic performances of BBMC based on the double-loop control strategy are discussed. The results show that the output voltage and frequency can be almost constant with the BBMC and double-loop control strategy despite of the changeable input voltage and frequency. Moreover, a high-quality sine output wave with low harmonic distortion can be directly obtained without filtering. So it can be drawn that the BBMC based on the double-loop control strategy has perfectly dynamic performance and practical importance to the engineering.

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

    DEFF Research Database (Denmark)

    Dimopoulos, Emmanouil; Munk-Nielsen, Stig

    2014-01-01

    the effective operational range of the power electronic converter. In this paper, a bidirectional tapped-inductor buck-boost converter is proposed, addressing high-efficient high step-up and high step-down voltage conversion ratios, for energy harvesting applications based on DEAP generators. The effective...... operational range of the converter is extended, by replacing its high-side switch with a string of three serialized MOSFETs, to accommodate the need for high-efficient high-voltage operation. Experiments conducted on a single DEAP generator - part of a quadruple DEAP generator energy harvesting system...... with all elements installed sequentially in the same circular disk with a 90 phase shift - validate the applicability of the proposed converter, demonstrating energy harvesting of 0.26 J, at 0.5 Hz and 60 % delta-strain; characterized by an energy density of 1.25 J per kg of active material....

  18. BLDCM Control System Based on Buck-Boost Converter%基于Buck-Boost变换器驱动的无刷直流电动机控制系统

    Institute of Scientific and Technical Information of China (English)

    孟武胜; 王波; 何博

    2011-01-01

    An improved topology of brushless DC motor drive with a Buck-Boost converter before 3 phase inverter,The motor can be controlled by technique-multi-loop. This method can reduce switching losses,the inverter size and cost. Effectiveness and feasibility of the proposed control method was verified by MATLAB/Simulink.%提出在无刷直流电动机的驱动三相逆变桥的输入端加前级降压-升压(Buck-Boost)变换器,采用转速和直流母线电流的多环反馈控制方法实现电机的控制.该方法减少了开关损耗,逆变器尺寸和成本.通过MAT-LAB/Simulink仿真验证了该方法的有效性和可行性.

  19. Application of Boost-Buck DC/DC Converter with Pure Digital Control%全数字控制B00st-Buck DC/DC变换器的应用

    Institute of Scientific and Technical Information of China (English)

    沈文轩; 吕承明

    2001-01-01

    讨论了实现全数字控制Boost-Buck DC/DC变换器的主电路拓扑结构、控制电路原理、软件控制方案.该变换器具有简单、实用、可靠的优点,被成功地应用在直流屏中作为220V直流母线.

  20. 基于ARM控制的交流BUCK-BOOST电路分析与设计%The Analysis of AC BUCK-BOOST Circuit Based on ARM Control and Its Design

    Institute of Scientific and Technical Information of China (English)

    刘文江; 张晓军; 王旭光

    2006-01-01

    提出和设计了一种新型BUCK-BOOST AC-AC变换电路,详细阐述了其结构和工作原理.该电路采用ARM嵌入式处理器和先进的控制策略,实现了全数字控制.实验结果表明,该电路具有很好的调压效果.

  1. Topological Design and Modulation Strategy for Buck-Boost Three-Level Inverters

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Teodorescu, Remus

    2009-01-01

    can perform distinct five-level line voltage and three-level phase voltage switching by simply controlling the active switches located in the designed voltage boost section of the circuits. As a cost saving option, one active switch can further be removed from the voltage boost section of the circuits...

  2. 升降式交流斩波器%Buck-Boost AC/AC Direct Converter

    Institute of Scientific and Technical Information of China (English)

    孙刚; 洪峰

    2009-01-01

    介绍了一种新颖的Buck-Boost型交流斩波器.该交流斩波器将Buck-Boost型DC/DC变换器的开关管双向化,可实现单级降压或升压的AC/AC直接变换和能量双向流动.该变换器使用较少的功率器件实现了单级功率变换和能量双向流动,有利于提高变换器的功率密度和变换效率.详细研究了其工作模态和原理.分析了该变换器的两种PWM调制策略,并指出采用第2种调制策略可降低开关损耗.采用滞环电流控制的Buck/Boost型交流斩波器可对输入电压畸变进行有效抑制,保持了输出电压波形的高度正弦化.仿真和实验验证了分析的正确性.

  3. Simulated Analysis of APFC for BUCK- BOOST Converter with Matlab%用Matlab实现BUCK-BOOST变换器 APFC的仿真分析

    Institute of Scientific and Technical Information of China (English)

    刘宇; 谢品芳; 周雒维

    2001-01-01

    本文分析了用BUCK-BOOST电路进行功率因素校正的原理和变换过程,给出了BUCK-BOOS电路的Matlab仿真分析的模型.通过对变换器工作在DCM模式下的电路仿真,验证了此方法具有良好的效果.

  4. Analysis, control and design of a non-inverting buck-boost converter: A bump-less two-level T-S fuzzy PI control.

    Science.gov (United States)

    Almasi, Omid Naghash; Fereshtehpoor, Vahid; Khooban, Mohammad Hassan; Blaabjerg, Frede

    2017-03-01

    In this paper, a new modified fuzzy Two-Level Control Scheme (TLCS) is proposed to control a non-inverting buck-boost converter. Each level of fuzzy TLCS consists of a tuned fuzzy PI controller. In addition, a Takagi-Sugeno-Kang (TSK) fuzzy switch proposed to transfer the fuzzy PI controllers to each other in the control system. The major difficulty in designing fuzzy TLCS which degrades its performance is emerging unwanted drastic oscillations in the converter output voltage during replacing the controllers. Thereby, the fuzzy PI controllers in each level of TLCS structure are modified to eliminate these oscillations and improve the system performance. Some simulations and digital signal processor based experiments are conducted on a non-inverting buck-boost converter to support the effectiveness of the proposed TLCS in controlling the converter output voltage.

  5. Comparison of the Impedance-Source Networks for Two and Multilevel Buck-Boost Inverter Applications

    DEFF Research Database (Denmark)

    Husev, Oleksandr; Blaabjerg, Frede; Roncero-Clemente, Carlos

    2016-01-01

    Impedance-source networks are an increasingly popular solution in power converter applications, especially in single-stage buck–boost power conversion to avoid additional front-end dc–dc power converters. In the survey papers published, no analytical comparisons of different topologies have been...... described, which makes it difficult to choose the best option. Thus, the aim of this paper is to present a comprehensive analytical comparison of the impedance-source-based buck–boost inverters in terms of passive component count and semiconductor stress. Based on the waveform of the input current, i...... in the inductors and the voltage ripple across the capacitors. Two-level and multilevel solutions are described. The conclusions provide a “one-stop” information source and a selection guide of impedance-source-based buck–boost inverters for different applications....

  6. Wind-Photovoltaic Hybrid Double-Input Buck-Boost DC/DC Converter%风光互补双输入Buck-Boost直流变换器的研究

    Institute of Scientific and Technical Information of China (English)

    廖志凌; 徐艳杰; 施卫东

    2014-01-01

    Instability and intermittency are two main drawbacks of independent solar energy generation. Therefore, it is essential to use a double-input DC/DC converter, which combines wind with solar to form a hybrid energy system. The paper proposes a new double-input Buck-Boost DC/DC converter with the following advantages: simple circuit, high voltage gain, and allowance of individual or simultaneous power delivery of the two sources. The operation principle of the double-input Buck-Boost DC/DC converter is analyzed, and the steady-state relation between convert input and output is presented. Finally, simulation results with PSPICE software are used to verify the theoretical analysis.%采用双输入直流变换器将太阳能和风能联合构成双输入供电系统,可避免独立光伏发电系统电力供应不稳定和不连续的缺点。本文提出一种新的双输入Buck-Boost直流变换器,具备电路结构简单、电压增益高特点,联合供电系统既可同时向负载供电,又可分体单独向负载供电。分析双输入Buck-Boost直流变换器的工作原理,给出变换器的输入/输出稳态关系式,并通过PSPICE软件进行仿真。仿真结果验证了理论分析的正确性。

  7. Buck-BOOst DC-DC变换器中分叉与混沌问题的研究(Ⅱ)--数值分析与实验%Study of Bifurcation and Chaos in the Current-Mode Controlled Buck-Boost DC-DC Converter ( Ⅱ ) --Numerical Analysis and Experiment

    Institute of Scientific and Technical Information of China (English)

    吴捷; 刘明建; 杨苹

    2002-01-01

    研究了电流控制型Buck-Boost变换器中的分叉与混沌问题.在连续模式下的Buck-Boost变换器的离散数学模型基础上,从不动点及稳定性理论的角度对Buck-Boost变换器的第一分叉点进行了严格的数值分析,得到了三维参数空间曲面图.此外,建立了实验硬件电路,实验结果验证了理论分析.%The first flip bifurcation point of Buck-Boost converter has been studied in detail by using fixed point and stability theory. 3-D parameter space of stable region is given. Furthermore, the hardware of 20kHz current-moxe controlled BuckBoost converter has been built and the experiment results verify the theoretical analysis which has been presented in our other papers.

  8. BOOST-BUCK converter-based photovoltaic-battery charging system%基于BOOST-BUCK电路的光伏脉冲充电系统

    Institute of Scientific and Technical Information of China (English)

    涂小伟; 陈皓

    2012-01-01

    太阳能光伏发电作为一种具有广阔前景的绿色能源已成为工业界和国内外学术界研究的热点,针对离网型光伏发电系统,分析了BOOST电路和BUCK电路在最大功率点跟踪(MPPT)电路中的缺点,提出了一种基于BOOST-BUCK电路的蓄电池脉冲充电电路,采用PIC16F877单片机进行智能控制,并绘制了单片机控制的N/D采样电路及外围电路.实验结果表明:一是实现了对蓄电池的脉冲充电;二是与BOOST、BUCK电路相比,大大提高了系统的工作效率.%As a green energy,solar photovoltaic technology has a wide prospect and it has been the research hotspot in industrial circles and the academic circles.In this paper,a battery charging circuit controlled by PIC microcontroller for stand-alone photo -voltaic power generation was presented.The shortcomings of the BUCK and BOOST circuits applied in the MPPT circuit were analyzed.The experimental result shows that the pulse charging method is used to charge the battery,which can extend the life of battery and improve system efficiency.

  9. Exploration of the Chaotic Behaviour in a Buck-Boost Converter Depending on the Converter and Load Elements

    Science.gov (United States)

    Demirbaş, Şevki; Fidanboy, Hikmet; Kurt, Erol

    2016-08-01

    In this paper, detailed analyses of the chaotic behavior observed in a buck-boost converter are presented. Although this basic converter system is already known world-wide for the purpose of dc-dc conversion of the output of renewable energy systems, it indicates certain chaotic regimes where both the output amplitude and frequency change randomly. This chaotic regime can yield an unstable output over the resistive or resistive/inductive electrical loads. This study presents a detailed map for the regular and chaotic regions in terms of material parameters, such as converter capacitance C, resistive load R, and inductive load L. Thus, the stable area of operation for efficient and renewable electricity production will be ascertained for the studied converter system. We emphasize that the material parameters C, R, and L play important roles in generating energy from the solar cell; indeed, the stability increases with higher values of the converter capacitor and load inductance, whereas it decreases according to the resistive load. A number of periodic windows have been observed and the output frequency gives a broad-band spectrum of up to 50 kHz.

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

    Science.gov (United States)

    Dimopoulos, Emmanouil; Munk-Nielsen, Stig

    2014-03-01

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

  11. Single-Switch Equalization Charger Using Multiple Stacked Buck-Boost Converters for Series-Connected Energy-Storage Modules

    Science.gov (United States)

    Uno, Masatoshi; Tanaka, Koji

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

  12. 几种新型的Buck-Boost变换器的合成%Synthesis of Several Novel Buck-Boost Converters

    Institute of Scientific and Technical Information of China (English)

    朱继承; 蔡丽娟

    2008-01-01

    从传输机制说明单管升降压变换器(如Buck-Boost、SPEIC、Cuk)中元件承受的电压和电流应力高的原因,并根据这一机制,采用变换器合成的方式,提出了一系列的双管Buck-Boost变换器.这类变换器根据输入输出条件,可以分别工作于Boost模式和Buck模式,起到降低元件应力的作用.

  13. Buck-Boost型变换器电路结构及其演化%Circuit Configuration and Derivation of the Buck-Boost Converter

    Institute of Scientific and Technical Information of China (English)

    张灵改; 陈道炼

    2009-01-01

    论述了基于Buck-Boost型变换器的DC/DC,DC/AC和AC/AC变换器电路结构及其演化过程,给出了各类变换器的电路拓扑实例、仿真和原理试验结果.理论分析、仿真和原理试验结果表明,Buck-Boost型变换器在中小容量的DC/DC.DC/AC和AC/AC电能变换中具有重要的应用价值.

  14. 一种用于光伏发电系统的Buck和Boost组合变换器研究%Study of a Cascaded Buck and Boost Converter for the Photovoltaic Power Generation System

    Institute of Scientific and Technical Information of China (English)

    孙向东; 张琦; 吴迎丰; 钟彦儒; 任碧莹

    2011-01-01

    为适用于光伏发电系统宽范围的光伏阵列输出电压情况,将传统的Buck变换器与Boost变换器相结合,采用变换器合成的方式,研究了一种双开关Buck和Boost组合变换器.针对传统的Buck-Boost变换器控制比较复杂的缺点,根据该变换器的输入输出条件提出了三种工作模式,即Boost模式,Buck模式和临界模式.分析了该变换器的工作原理及其控制策略.与传统的Buck-Boost变换器相比较其具有正极性的输出电压和更宽的输入电压范围.仿真与实验结果表明该电路性能优良.%In order to meet the needs of PV array output voltage in the wider range of PV generation system, the conventional Buck converter is combined with Boost converter in this paper. The combination means of converter is adopted to study a double-switch cascaded Buck and Boost. With an aim at the complicated disadvantages of the conventional Buck-Boost converter control and based on the input and output voltage conditions of the converter, three types of operation modes are suggested: i.e. Boost-voltage mode,Buck-voltage mode and critical operation mode. The operation principle of the converter and its control strategy are analyzed. Compared with the conventional Buck-Boost converter, its output voltage is positive and the input voltage ranges are wider. The simulation and experiment results prove that the cascaded Buck and Boost converter has good performance.

  15. 双管Buck-Boost变换器的输入电压前馈控制策略%An Input Voltage Feedforward Control Strategy for Two-switch Buck-Boost DC-DC Converters

    Institute of Scientific and Technical Information of China (English)

    姚川; 阮新波; 曹伟杰; 陈沛琳

    2013-01-01

    The two-switch Buck-Boost (TSBB) converter is suitable for wide input voltage applications, and a two-mode control scheme with two modulation signals and one carrier can be adopted to achieve high efficiency and automatic modes-switching over the entire input voltage range. The corresponding operating modes are the Buck mode with high input voltages and the Boost mode with low input voltage. In order to reduce the influence of the input voltage disturbance on the output voltage, input voltage feed-forward (IVFF) functions based on the small-signal models of different operating modes were derived, and the effect of the variable circuit parameters on the IVFF functions was analyzed, then a two-mode control scheme with IVFF compensation was proposed. With this proposed control scheme for the TSBB converter, automatic selections of operating modes and the corresponding IVFF functions can be achieved simultaneously. Besides, nearly smooth switching between Buck and Boost modes is guaranteed. Then, high efficiency and improved input transient response over the entire input voltage range are both achieved. For exhibiting the advantages of the proposed control scheme clearly, comparisons between the two-mode control with and without IVFF compensation had been presented in this paper. Finally, a suitable power prototype was fabricated to validate the effectiveness of the control scheme.%  双管Buck-Boost变换器适用于宽输入电压范围场合。采用双调制–单载波的两模式控制策略可实现其整个输入电压范围内的高效率和工作模式的自动平滑切换,其工作模式即为高输入电压区间的 Buck 模式和低输入电压区间的Boost模式。为抑制输入电压扰动对输出电压的影响,通过建立双管Buck-Boost变换器不同工作模式下的小信号模型,推导相应的输入电压前馈函数,并分析电路参数变化对前馈函数的影响,进而提出一种带输入电压前馈的两模式控制

  16. Dual Edge Modulated Four-switch Buck-Boost Converter%双沿调制的四开关Buck-Boost变换器

    Institute of Scientific and Technical Information of China (English)

    任小永; 阮新波; 李明秋; 钱海; 陈乾宏

    2009-01-01

    与传统的Buck-Boost变换器相比,四开关Buck-Boost变换器具有输入输出同极性、开关管电压应力低等优点.该文针对四开关Buck-Boost变换器在通信电源分布式系统中的应用,提出三模式双频双沿调制的控制策略.该控制策略将变换器分成Buck单元和Boost单元,此两单元分别采用后沿调制和前沿调制,并且在Buck.Boost工作模式时,开关频率由Buck以及Boost模式的200 kHz降到40 kHz,以提高变换器的效率.实验室制作了一台48V(33~75 V)输入48 V/6.25 A的样机,对所提出的控制策略进行验证.试验结果表明所得结论正确.

  17. 交错并联双向Buck/Boost集成LLC谐振型三端口直流变换器%Interleaved Bidirectional Buck/Boost and LLC Integrated Three-Port DC-DC Converter

    Institute of Scientific and Technical Information of China (English)

    孙孝峰; 申彦峰; 李午英; 王宝诚

    2016-01-01

    将交错并联双向 Buck/Boost 电路与全桥 LLC 谐振电路通过共用全桥开关单元集成在一起,提出了一种新型的三端口直流变换器,实现了器件共享,降低了体积和成本。该三端口变换器包括两个双向端口和一个隔离的单向输出端口,通过PWM+PFM的混合调制策略,可实现端口间功率流的灵活控制。与传统的移相全桥集成型三端口直流变换器相比,提出的变换器输入电流纹波小,可在宽电压和功率范围内实现一次侧开关管的零电压软开关(ZVS)和二次侧整流二极管的零电流软开关(ZCS)关断,开关损耗小,而且不存在占空比丢失、变压器直流偏磁等问题。研究了该三端口变换器的工作原理、工作模式和端口功率传输模式,并对其增益、软开关等特性进行了深入分析,最后搭建了一台500W的实验样机,实验结果验证了变换器的实用性和理论分析的正确性。%By integrating the two-phase interleaved bidirectional Buck/Boost circuit with the full-bridge LLC resonant circuit, a novel three-port converter (TPC) is proposed. Thus, the full-bridge switching unit is shared and the cost is reduced. The proposed TPC consists of two bidirectional DC ports and an isolated unidirectional DC port. With PWM plus PFM modulation strategy, flexible power flow control can be easily achieved. All primary power switches operate with ZVS and all secondary diodes can achieve ZCS-off in wide voltage and power ranges, thus the switching losses are reduced. In addition, the duty cycle loss and transformer DC bias current inherently existed in conventional phase shift full-bridge integrated TPCs, can be well eliminated in the proposed TPC combined with the LLC resonant tank. The basic operation principle, operation modes and power transfer modes of the proposed TPC are investigated. Then both the gain and the ZVS characteristics are analyzed in detail. Finally, the

  18. The Design and Implement of Digital Controller for Buck-Boost Converter%Buck-Boost变换器数字控制器的设计和实现

    Institute of Scientific and Technical Information of China (English)

    何炯; 吴定会; 纪志成

    2008-01-01

    利用分段线性电子电路仿真PLECS软件建立Buck-Boost变换器的仿真模型;采用幅值相位裕度方法设计控制器参数;基丁系统发生器提出了一种新的数字控制器实现方法,分析了负载扰动和电源扰动特性.并对其进行了实验.实验结果证明了PLECS建模和系统发生器设计的有效性,也为FPGA实现Buck-Boost变换器的数字控制器提供了新的设计流程.

  19. The Passivity-based Current Control Method for BUCK-BOOST Converter%BUCK-BOOST变换器的无源性电流控制方法

    Institute of Scientific and Technical Information of China (English)

    廖鸿飞; 帅定新; 梁奇峰; 彭建宇

    2013-01-01

    为了简化系统控制结构,提高Buck-Boost变换器的控制性能,提出了一种通过直接控制电感电流间接控制输出电压的Buck-Boost变换器无源性电流控制方法.首先根据无源性控制方法建立了系统的欧拉一拉格朗日能量模型,然后基于无源性理论和Layapunov稳定性理论,推导出了系统的无源性控制规律.实验结果表明,系统输出电压稳定,鲁棒性较强,动态响应良好.

  20. Fractional Order Modeling and Analysis of Buck-Boost Converter%基于分数阶Buck-Boost变换器建模与分析

    Institute of Scientific and Technical Information of China (English)

    伊利峰; 张开如; 刘军

    2015-01-01

    Buck-Boost变换器应用相关分数阶微积分理论建立基于电感电流连续模式下分数阶数学模型,然后理论分析建立起来的分数阶数学模型.基于改进的分数阶微积分Oustaloup滤波器算法,建立电感电流连续模式下Buck-Boost变换器Matlab/Simulink分数阶仿真模型.最后,分数阶仿真结果与整数阶的结果进行分析比较,验证分数阶数学模型与理论分析的正确性.

  1. A Novel Four Switch Buck-Boost Converter%一种新颖的四开关Buck-Boost变换器

    Institute of Scientific and Technical Information of China (English)

    任小永; 唐钊; 阮新波; 危建; 华桂潮

    2008-01-01

    提出一种新颖的四开关Buck-Boost变换器及其控制策略.该变换器由Buck变换器和Boost变换器级联等效而成,其可以将宽范围的输入电压高效率变换到额定电压附近,这样对后级变换器而言输入就是一个窄范围,从而保证了后级变换器的优化设计;与此同时,四开关Buck-Boost变换器的滤波工作模式还保证了额定输入电压附近效率的最高.实验结果表明:采用文中提出的四开关Buck-Boost变换器作为前级的两级式变换器可以满足未来通信电源模块高效率、高功率密度以及宽输入范围的要求.

  2. Design of AC Regulator Based on Buck-Boost Converter%基于Buck-Boost的AC/AC变换器设计

    Institute of Scientific and Technical Information of China (English)

    张超华; 汤雨; 谢少军

    2007-01-01

    利用Buck-Boost电路输出电压理论上可以在零到无穷大之间变化的特点,将Buck- Boost斩波电路应用于交流电压变换,提出了一种变比可以连续变化的固态变压器.与传统的自耦调压器相比,基于Buck-Boost变换器的固态变压器具有输出电压范围宽、体积小的特点,并且由于采用了电压反馈控制,使得其输出电压不受负载变化的影响,外特性较硬.针对四象限开关存在的换流问题,提出了该变换器的换流策略,在理论分析的基础上,设计制作了一台AC/AC调压器,实验结果验证了该变换器的可行性.

  3. 耦合电感宽输入有源升降压逆变器%Wide Input Active Boost-Buck Inverter With Coupled Inductors

    Institute of Scientific and Technical Information of China (English)

    吴冬春; 阚加荣; 汤雨; 何耀华

    2014-01-01

    传统升压电路由于占空比的限制,升压能力有限,要使输出电压恒定,输入直流电压不能太低。提出了一种耦合电感宽输入有源升降压逆变器,分析了电路的工作模态、开关管应力和电路增益。通过设置耦合电感的匝比,在输入电压较低时,该电路可以实现较高幅值的交流电压输出;输入电压较高时可以实现降压逆变。适时修正耦合电感 Boost AC/AC 电路的占空比,可以使电路增益保持恒定。仿真和实验结果表明该电路能够在较宽的输入电压范围内实现升压和降压逆变。%Due to the restriction of duty cycle the boost capacity of traditional boost circuit is constrained, therefore to make the output voltage constant the input DC voltage cannot be too low. A wide input active boost-buck inverter with coupled inductors is proposed, and the operating mode of the circuit, the voltage stress of the valves and the gain of the circuit are analyzed. By means of setting the turn-ratio of the coupled inductors, the proposed circuit can output AC voltage with higher amplitude under lower input voltage;and the buck inversion can be implemented under higher input voltage. Modifying the duty ratio of the boost AC/AC circuit of the coupled inductors in time can make the gain of the circuit constant. Results of simulation and experiments show that using the proposed circuit the voltage boost and buck can be implemented within a wider input range of voltage range.

  4. Research on Buck-Boost Double Half Bridge DC/DC Converter%Buck-Boost型双半桥DC/DC变换器研究

    Institute of Scientific and Technical Information of China (English)

    施林涵; 林国庆; 徐质彬; 林威伟

    2016-01-01

    本文设计了一个应用于光伏系统中的Buck-Boost型双半桥DC/DC变换器,研究一种PWM控制与移相控制结合的充电与供电控制策略:通过移相控制实现光伏电池对负载的供电,通过PWM控制实现光伏电池对蓄电池的充电.最后结合仿真和实验结果,验证了该方案的可行性.

  5. Buck-Boost变换器的环路补偿及仿真%Loop Compensation and Simulation of Buck-Boost Converter

    Institute of Scientific and Technical Information of China (English)

    于月森; 戚文艳

    2014-01-01

    设计DC-DC变换器时为了使其满足静态和动态指标的要求,一般需要设计良好的补偿网络,而变换器输出滤波电容的等效串联电阻ESR对补偿网络的影响是不可忽略的.为了探究等效串联电阻对补偿网络的影响,该文采用波特图法对工作在连续工作模式(CCM模式)下的Buck-Boost变换器的稳定性进行分析,并讨论了有无ESR时补偿器的设计方案,结果显示ESR不同,选用的补偿方案也不同;然后利用Matlab工具对补偿后的Buck-Boost变换器进行仿真,验证补偿网络设计的正确性.

  6. PT controlled PCCM Buck-Boost converter with two control variables%两控制变量PT控制PCCM Buck-Boost变换器

    Institute of Scientific and Technical Information of China (English)

    秦明; 李芳芳

    2016-01-01

    为减小电感惯性模态期间电感电流下降对下一周期脉冲的影响,根据伪连续导电模式(Pseudo ContinuousConduction Mode,PCCM) Buck-Boost变换器的工作特点,提出一种新的脉冲序列(Pulse Train,PT)控制策略.控制策略中包含两个控制变量,使控制器根据不同能量的电压控制脉冲产生不同的电流控制脉冲.详细分析了新型PT控制策略下PCCM Buck-Boost变换器的工作过程,给出了高低能量电压控制脉冲比.仿真与实验结果验证了新型控制策略的可行性及理论分析的正确性.

  7. Achieving Maximum Power from Thermoelectric Generators with Maximum-Power-Point-Tracking Circuits Composed of a Boost-Cascaded-with-Buck Converter

    Science.gov (United States)

    Park, Hyunbin; Sim, Minseob; Kim, Shiho

    2015-06-01

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

  8. Design of wide output voltage AC-DC power supply based on buck-boost circuit%基于Buck-Boost电路的宽输出电压AC-DC电源设计

    Institute of Scientific and Technical Information of China (English)

    徐文城; 刘尧; 王秀荣

    2012-01-01

    设计了一种宽输出电压的AC DC开关电源,其主要特征是输出电压可以在较大范围内任意调节,解决了传统的开关电源只能输出几个特定电压值的问题.该设计的核心是反激变换电路和Buck-Boost电路.分析了这两种电路的工作原理及其应用,并且给出了具体的设计.实验表明,设计的电源能较好地实现了输出电压的宽范围调节.%AC-DC switching power supply with a wide range voltage output was designed. Its main feature is that the output voltage can be adjusted in a wide range. The problem that the traditional switching power supplies only have few specific voltage outputs is solved in the design. The flyback convert circuit and Buck-Boost circuit are the cores of the design. The working principle and applications of these two circuits are analyzed. The concrete design is given in this paper. The experiments show that a wide range regulation of the output voltage has been more successfully achieved in the design of the power supply.

  9. Dynamical and steady-state characteristics of DC motors powered by photovoltaic systems via DC-DC buck-boost switch mode converter

    Energy Technology Data Exchange (ETDEWEB)

    Widyan, M.S.

    2010-07-01

    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.

  10. Convertidor buck-boost controlado digitalmente con histeresis cero mediante un dsp; Back-Booost Converter digitally controlled by zero hysteresis method, using DSP

    Directory of Open Access Journals (Sweden)

    Fredy Edimer Hoyos Velasco

    2011-02-01

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

  11. Buck/Boost集成双有源桥三端口DC-DC变换器%Dual Buck/Boost Integrated Dual Active Bridge Three-Port DC-DC Converter

    Institute of Scientific and Technical Information of China (English)

    孙孝峰; 刘飞龙; 熊亮亮; 王宝诚

    2016-01-01

    In this paper, Dual Buck/Boost integrated dual active bridge (DAB) three-port DC-DC converter combines the conventional DAB and two bidirectional Buck/Boost circuits. Hence power switches are shared, and the power density is improved. The PV-battery hybrid power system is taken as an example to analyze the proposed converter topology. The phase shift plus PWM control is adopted here. The phase shift angle is used to control the power flow between the input port and the output port, while the duty cycle is employed to match the input voltages. Thus the maximum power point tracking (MPPT) can be achieved and the power flow between PV and battery can be balanced. The basic operation principles, steady state characteristics and zero voltage switching (ZVS) conditions are analyzed. The ZVS conditions for the conventional DAB operating in small phase shift angle can be greatly improved, and thus the converter can operate under ZVS in a wide operation range. A 300 W converter prototype is built to verify all considerations.%在传统的双有源桥变换器的基础上集成两个双向 Buck/Boost 电路,提出了一种双Buck/Boost 集成双有源桥三端口 DC-DC 变换器,该变换器实现了桥臂开关管的复用,提高了功率密度。以光伏-蓄电池混合发电系统为例对该变换器拓扑进行分析,采用移相+PWM进行控制,通过控制移相角实现输入与输出端口间功率传输,通过调节占空比来匹配输入端口电压等级,以实现光伏端口的最大功率点跟踪和平衡蓄电池端口的能量传递。分析了该变换器的工作原理、稳态与软开关特性,该变换器较大程度地改善了传统移相控制下 DAB 在移相角较小时的软开关条件,使得在宽工作范围内能够实现所有功率开关管的软开关。最后建立300W实验样机进行方案验证。

  12. 新颖的Buck-Boost高频环节AC/AC变换器%Novel Buck-Boost AC/AC Converters with High Frequency Link

    Institute of Scientific and Technical Information of China (English)

    刘剑; 陈道炼; 尹春

    2004-01-01

    提出了Buck-Boost高频环节AC/AC变换器电路拓扑,该电路拓扑由输入周波变换器、高频储能式变压器、输出周波变换器构成.分析研究了该变换器工作模式和电压瞬时值反馈控制策略.理论分析和试验表明,该变换器具有两级功率变换(LFAC/HFAC/LFAC)、双向功率流、网侧电流波形可得到改善、负载适应能力强、音频噪音小等优点.

  13. 高动态响应的Buck-Boost变换器的边界控制%Boundary Control of Buck-Boost Converter with Fast Response

    Institute of Scientific and Technical Information of China (English)

    马朋; 陆益民

    2007-01-01

    应用状态轨迹预测的方法,调节Buck-Boost变换器电压输出.根据在一个假定的开关动作后预测电压输出,设计二阶开关面,在一个开关周期内就可引导系统轨迹到达目标工作点,具有大信号稳定性,对负载扰动及电源扰动均有很强的自适应性,通过仿真验证了理论的正确性.

  14. Buck/boost regulator

    Science.gov (United States)

    Paulkovich, J.; Rodriguez, G. E. (Inventor)

    1981-01-01

    A voltage regulated DC to DC converter uses an inductor and a capacitor as storage elements. The inductor is composed of two windings having a common junction. A transformer with a center tap connected to the common junction of the two windings is connected at either end of its winding to ground through controlled switches. One winding of the inductor and either end of the transformer winding are connected by power diodes to the capacitor which supplies the output voltage to a load. The other winding of the inductor is connected to a fourth power diode as a clamping diode. Input voltage is supplied to the inductor through a third controlled switch. A pulse width modulator connected to the output of the converter alternately closes and opens the switches connected to either end of the transformer winding and also closes the switch supplying input voltage to the inductor each time either of the switches connected to the ends of the transformer winding are closed. The duty cycle of the closing and opening of the several switches is adjusted by the pulse modulator to regulate the output voltage.

  15. Design of isolated Buck-Boost DC/DC converter%Buck-Boost隔离直流转换器设计

    Institute of Scientific and Technical Information of China (English)

    王雪丹; 李文鹤

    2013-01-01

    Buck-Boost隔离直流转换器宽范围输入电压的条件下,分析了典型的全桥boost转换器拓扑结构,由于存在的谐振电感包括漏电感,全桥Boost转换器只能采用双边沿调制[1],该转换器采用UC3895作为控制器,对全桥单元采用移相转换控制的方式,为了提高全桥boost转换器系统的可靠性和效率,采用三模式两频率控制方式[2],在输入宽范围电压的情况下,最高输入500V,输出360V,采用Matlab软件进行仿真,实验结果表明输入电压平均效率范围是96.2%,最高效率能达到97.5%.

  16. Research on NMVS Passive Lossless Soft Switching Method Based on Buck/Boost Converters%基于Buck/Boost变换器的NMVS无源无损软开关

    Institute of Scientific and Technical Information of China (English)

    李雪莉

    2011-01-01

    针对有源无损缓冲电路结构和控制复杂的缺陷,开发了一种基于无源无损缓冲技术和谐振技术组合并在Buck/Boost变换器上实现,以此来设计具有非最小电压应力缓冲结构的软开关,通过对其7种工作模式下的工作流程分析,得到NMVS无源无损软开关电路单元并将缓冲元件的能量回馈给变换器的输入输出端,实现了无损的效果,并通过理论计算给出其具体的参数.与硬开关条件下的开关电流电压实验波形仿真对比,证实了其开关范围更广、效率更高、结构简单、性价比高,易于控制等优点.%Considering the shortcoming of active lossles snubber circuits and complicated control, a soft switching method which has voltage stress (MVS) passive lossless switching technology and resonant technology combined and implemented in Buck/Boost converters was proposed to develop a NMVS passive lossless soft switching. Through analyzing its working process in 7 different modes, the NMVS passive loss1ess soft switching circuit cell can feed back the energy of buffers to the converter input and output sides to achieve a loss1ess effect. The experimental result proves the success of theoretical analysis.

  17. Control Strategy Research of Buck-Boost Matrix Converter Based on Fuzzy PI Control%基于模糊PI控制的Buck-Boost矩阵变换器控制策略研究

    Institute of Scientific and Technical Information of China (English)

    陈琪; 李旋

    2013-01-01

    针对一种具有优良电气特性的新型Buck-Boost矩阵变换器(BBMC)采用基于模糊PI的双闭环控制策略进行控制。阐述了该变换器的基本原理,研究了基于模糊PI的双闭环控制的具体设计方法。并采用MATLAB对其控制效果进行了仿真验证。结果表明:当BBMC输入侧电压发生突变时,模糊控制器能有效调节PI参数,使输出电压有效的跟随输入电压的变化而变化,从而系统迅速达到稳定。%According to a new Buck-Boost matrix converter (BBMC) having excellent electrical performance,uses the double closed loop control strategy based on fuzzy PI. This paper expounds the basic principle of the converter, studies the design method of double closed loop control based on fuzzy PI, and uses the MATLAB for the simulation of the control effect. The results show that, when the BBMC input voltage change, the fuzzy controller can effectively adjust the PI parameters, making the change of the output voltage effectively follow the change of the input voltage, thus the system rapidly reaches stable.

  18. Research on the Influence of Switching Frequency on Low-Frequency Oscillation in the Voltage-Controlled Buck-Boost Converter

    Directory of Open Access Journals (Sweden)

    Faqiang Wang

    2011-01-01

    Full Text Available The influence of switching frequency on the low-frequency oscillation in the voltage-controlled buck-boost converter is studied in this paper. Firstly, the mathematical model of this system is derived. And then, a glimpse at the influence of switching frequency on the low-frequency oscillation in this system by MATLAB/Simulink is given. The improved averaged model of the system is established, and the corresponding theoretical analysis is presented. It is found that the switching frequency has an important influence on the low-frequency oscillation in the system, that is, the low-frequency oscillation is easy to occur when the switching frequency is low. Finally, the effectiveness of the improved averaged model and the theoretical analysis are confirmed by circuit experiment.

  19. 采用耦合电感的Buck/Boost集成型三端口直流变换器%A Buck/Boost Integrated Three-port DC-DC Converter with Coupled Inductors

    Institute of Scientific and Technical Information of China (English)

    蒋丹; 刘福鑫; 毛韵雨; 阮新波

    2014-01-01

    In the hybrid renewable power system,a multi-port DC-DC converter can be introduced instead of the numerous individual DC-DC converters,leading to a simpler configuration and a lower cost.In high current applications,a Buck/Boost integrated three-port DC-DC converter with coupled inductors is proposed.Two interleaved inductors are introduced to obtain a symmetrical structure and achieve an inherent current sharing.For further optimization of the converter,two inductors can be coupled in an inverse manner.The converter topology is described,along with its control strategy and operating principle.The influence on the current ripples of the coupled inductors is discussed.The effective values of the current of switches and the zero voltage switching range with variable coupling coefficients are analyzed under ideal conditions.Finally,the theoretical analysis is validated by experimental results from a 1 kW prototype.%新能源联合供电系统中,多端口直流变换器可代替原有多个分立变换器,以简化系统结构、降低成本。针对大电流应用场合,提出一种采用耦合电感的 Buck/Boost 集成型三端口直流变换器,通过电感交错并联使桥臂结构一致,同时实现电流扩容与纹波抑制,将两电感反向耦合,进一步改善变换器性能。文中给出其拓扑结构与控制策略,讨论其工作原理,重点分析了电感电流脉动、开关管软开关实现范围及开关管电流有效值与耦合系数的关系,并通过一台1 kW的原理样机进行了实验验证。

  20. Analysis on Control Strategy of Two-switch Buck-Boost Converter for Photovoitaic Interface in DC Microgrid%基于双管Buck-Boost变换器的直流微电网光伏接口控制分析

    Institute of Scientific and Technical Information of China (English)

    杨晨; 谢少军; 毛玲; 秦岭

    2012-01-01

    Based on the control requirements of photovoltaic interface in the distributed DC power system, a control strategy for photovoltaic converter is proposed. Taking two-switch Buck-Boost converter for example, the control system structure for the converter is introduced and the small signal model is established. The operating principle is analyzed and how to select the close-loop control parameters is discussed. Finally, the control strategy was carried out on a 3 kW two-switch Buck-Boost converter. The experimental results show that the photovoltaic interface can work effectively to match the basic control requirements.%分析了分布式直流供电系统中光伏接口单元的控制要求,给出了相应的控制策略。以双管Buck-Boost变换器型接口单元为例,介绍了其控制系统结构和小信号模型的建立,分析了接口变换器的工作过程,讨论了闭环控制参数选取依据。最后,在一台3kW的双管Buck-Boost变换器实验样机上,对理论分析进行了验证,实现了分布式直流供电系统光伏接口单元的基本控制功能。

  1. The Controller Based on the Buck/Boost solar LED street lamp%基于Buck/Boost太阳能LED路灯控制器

    Institute of Scientific and Technical Information of China (English)

    曲帅帅; 王志坤

    2014-01-01

    本系统以STC12C5410AD单片机为核心,以两只VMOS管为基本控制单元,在电路极为简单自身功耗很小的情况下实现了对太阳能路灯系统的智能化管理;系统采用了一种自适应性算法的MPP最大功率追踪控制法,实现了在同样光照条件下太阳能电池发电量最大化的控制,设计了电池板智能追光与自动清洁板面的机械结构,使各个时间段的光线与电池板都能保持最佳角度,同时做到了强光时降压防过充、弱光时升压继续充的全功能充电控制。%this system with STC12C5410AD MCU as the core,with two VMOS tube as a basic control unit,in the circuit is extremely simple to very smal self power consumption under the condition of realization of solar streetlight system intel igent management;system using an adaptive algorithm of the MPP maximum power tracking control method,realized in the same light under the condition of maximum power output of the solar battery control,design of intel igent light battery plate with automatic cleaning surface mechanical structure,so that each time the light and battery plate can keep the best angle,at the same time to light pressure overcharge protection,weak light booster continue to charge the ful functionality of the charging control.

  2. Comparison Study of One Cycle Control and Average Current Control for Bridgeless Buck-Boost PFC Converters%无桥Buck-Boost PFC变换器中单周期控制与平均电流控制的对比研究

    Institute of Scientific and Technical Information of China (English)

    赵犇; 马瑞卿

    2015-01-01

    单周期控制由于其动态响应好、抗干扰性强、控制电路实现简单,被广泛运用在传统Boost类PFC变换器中.针对一种新型的无桥Buck-Boost PFC变换器拓扑,研究了单周期控制与传统平均电流控制在该类型拓扑中的应用.通过原理分析,证明了在无桥类拓扑中单周期控制可以避免平均电流控制所必须采用的输入电压检测,其电路实现更容易,成本更低廉;同时,通过仿真验证了单周期控制比平均电流控制的动态响应更快.证明了在无桥Buck-Boost类PFC变换器中,单周期控制比平均电流控制更具优势,性价比更高.

  3. A 0.04 mm (2) Buck-Boost DC-DC Converter for Biomedical Implants Using Adaptive Gain and Discrete Frequency Scaling Control.

    Science.gov (United States)

    George, Libin; Gargiulo, Gaetano Dario; Lehmann, Torsten; Hamilton, Tara Julia

    2016-06-01

    This paper presents the design of a reconfigurable buck-boost switched-capacitor DC-DC converter suitable for use in a wide range of biomedical implants. The proposed converter has an extremely small footprint and uses a novel control method that allows coarse and fine control of the output voltage. The converter uses adaptive gain control, discrete frequency scaling and pulse-skipping schemes to regulate the power delivered to a range of output voltages and loads. Adaptive gain control is used to implement variable switching gain ratios from a reconfigurable power stage and thereby make coarse steps in output voltage. A discrete frequency scaling controller makes discrete changes in switching frequency to vary the power delivered to the load and perform fine tuning when the output voltage is within 10% of the target output voltage. The control architecture is predominately digital and it has been implemented as part of a fully-integrated switched-capacitor converter design using a standard bulk CMOS 0.18 μm process. Measured results show that the converter has an output voltage range of 1.0 to 2.2 V, can deliver up to 7.5 mW of load power and efficiency up to 75% using an active area of only 0.04 mm (2), which is significantly smaller than that of other designs. This low-area, low-complexity reconfigurable power converter can support low-power circuits in biomedical implant applications.

  4. Buck-Boost Converter Control Based on Port-Controlled Hamiltonian Theory%基于端口受控哈密顿方法的Buck-Boost变换器控制

    Institute of Scientific and Technical Information of China (English)

    王勇; 于海生

    2007-01-01

    应用一种新的端口受控哈密顿(PCH)系统方法,研究了Buck-Boost变换器的建模与PWM控制问题.首先,建立了Buck-Boost变换器的PCH系统数学模型.然后,利用互联和阻尼配置的能量成形方法,给出了Buck-Boost变换器的反馈镇定原理.根据其稳态特性确定了系统期望的平衡点,分析了Buck-Boost变换器平衡点的稳定性,最后设计了控制器.仿真结果表明,该控制器具有很好的性能和应用前景.

  5. A Robust Chattering-Avoiding Sliding Mode Control for Buck-Boost Converter%一种鲁棒无抖颤滑模控制的Buck-Boost变换器

    Institute of Scientific and Technical Information of China (English)

    皇甫宜耿; 吴宇; 马瑞卿

    2014-01-01

    In the process of power generation by new energy sources, such as wind, light and hydrogen, the ran-domness of energy input and power output often appear;this puts forward higher requirements for the robust design of power converters. The power converter based on traditional sliding mode, due to its discrete control law, makes chattering phenomenon inevitable. In order to suppress the above problem, this paper presents a novel chattering-avoiding converter based on the super-twisting sliding modes. The core idea is to transfer the discrete control law to high order sliding manifold, essentially eliminating the impact of chattering effect. To remove the intermittent dis-turbance in the new energy power generation, this paper compares the effect of the converter controlled by super-twisting sliding mode controller with the classic PI controller in a typical Buck-Boost power converter as an example. The simulation results and their analysis show preliminarily that: (1) under the condition of large disturbances in input and output, the converter controlled by super-twisting sliding mode has stronger robustness;(2) in response tracking, the converter has a faster convergence;the frequency response can reach more than 20 Hz, far superior to the classic PI control.%利用风、光、氢等新能源发电过程中,经常遇到能量输入和功率输出的随机性,这对电源变换器鲁棒性设计提出了更高要求。针对传统滑模控制变换器由于自身控制律的离散型存在不可避免的抖颤问题,基于一种Super-Twisting控制算法设计无抖颤滑模变换器,其核心思想是将离散控制律转移至更高阶的滑模面,从本质上消除抖颤的影响。以电源变换器Buck-Boost为例,针对新能源发电中存在的间歇性扰动问题,与典型PI控制效果进行对比试验。仿真结果表明:1)动态滑模控制变换器在输入、输出大扰动下具有很强的鲁棒性;2)在频响跟踪方面具

  6. Analysis on the Passivity and Sliding-mode Control of the Buck-Boost Converter%Buck-Boost变换器的无源滑模控制研究

    Institute of Scientific and Technical Information of China (English)

    屈鲁

    2013-01-01

    为解决无源性控制时Buck-Boost变换器电压与电流过冲的问题,在无源性控制的基础上加入滑模控制.通过建立Buck-Boost变换器的欧拉-拉格朗日(E-L)模型,可以得到Buck-Boost变换器的无源性控制规律.在此基础上,结合滑模控制原理,设计Buck-Boost变换器的无源滑模控制器.在Matlab环境下,进行Buck-Boost变换器无源滑模控制的动态仿真.仿真结果表明,Buck-Boost变换器的无源滑模控制对电源扰动、负载扰动具有很强的鲁棒性,且动态响应速度快,能够解决无源性控制电压与电流过冲的问题.

  7. A Novel Average Model for Unified Buck-Boost DC/DC Converter%一种新型的升-降压型直流变换器电路仿真平均模型

    Institute of Scientific and Technical Information of China (English)

    康婉莹; 沈淼森; 钱江; 钱照明

    2001-01-01

    提出了一种新型的单开关升-降压式(Buck-Boost)直流变换器的电路仿真平均模型.这种模型可通过输入参数的选择实现对Buck-Boost电路的电压控制、峰值及平均电流控制,以及对DCM-CCM工作方式的统一.它是一种实用的仿真模型,可方便地进行稳态和动态分析.在保证准确的基础上,大幅度提高了仿真的速度,通常比用实际器件开关电路的仿真速度提高两到三个数量级.

  8. Soft switching buck-boost converter for photovoltaic power generation; Taiyoko hatsuden no tame no soft switching shokoatsu converter

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-27

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

  9. Analysis of Bifurcation in Marine Current-mode Controlled Buck-boost Converter%船用电流控制型Buck-boost变换器分岔行为分析

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    为了分析船用电流控制型Buck-boost变换器的分岔非线性动力学行为,首先推导一种描述船用Buck-boost变换器分岔行为演化过程的非线性迭代映射模型,然后采用雅可比矩阵来确定Buck-boost变换器首次出现失稳的分岔点,最后进行了不同分岔参数的仿真试验.仿真试验结果表明了理论推导模型的正确性,并且可有效预测首次出现的分岔点.

  10. 混沌态电流模式Buck-Boost开关变换器的OGY控制%OGY Control of the Chaotic Current Mode Buck-Boost Switching Converter

    Institute of Scientific and Technical Information of China (English)

    王利清; 魏学业; 温伟刚; 谢涛

    2005-01-01

    从电流模式Buck-Boost开关变换器周期-1状态的频闪采样离散时间迭代映射数学模型出发,提出了一种混沌态电流模式Buck-Boost开关变换器吸引子中不稳定周期-1轨道的确定方法.根据OGY控制的原理和思想,推导出OGY控制矢量的取值范围,以此为依据选择控制矢量,实现了对混沌态的电流模式Buck-Boost开关变换器相空间中的一条不稳定周期-1轨道的稳定控制.

  11. 电流反馈型Buck-Boost变换器的非线性动力学研究%STUDY ON NONLINEAR DYNAMICS BEHAVIORS BASED ON CURRENT-PROGRAMMED BUCK-BOOST CONVERTER

    Institute of Scientific and Technical Information of China (English)

    赵益波; 罗晓曙; 唐国宁; 翁甲强

    2005-01-01

    首先建立了电流反馈型buck-boost变换器的精确离散化模型,然后研究了变换器在不连续模式下的非线性动力学行为.通过研究发现:电流反馈型Buck-Boost变换器在不连续模式下,出现了特有的分岔和混沌现象.

  12. 基于Buck-Boost矩阵变换器的异步电机调速控制策略%A Buck-Boost matrix converter based strategy for control of the rotating speed of asynchronous motors

    Institute of Scientific and Technical Information of China (English)

    张小平; 尹翔; 刘士亚

    2014-01-01

    进行了将采用双闭环控制的Buck-Boost矩阵变换器用于异步电机调速系统控制的研究,设计了基于Buck-Boost矩阵变换器的异步电机调速控制策略.该策略根据异步电机的给定转速,基于矢量控制原理获得异步电机对应的输入电压,并以该电压作为Buck-Boost矩阵变换器的参考输出电压,再通过对Buck-Boost矩阵变换器采用双闭环控制策略使其实际输出电压与其参考输出电压保持一致,从而实现异步电机的实际转速对给定转速的准确跟踪,达到准确控制异步电机转速的目的.该控制策略的控制效果通过仿真得到了验证.仿真分析结果表明,异步电机采用基于Buck-Boost矩阵变换器的调速控制策略可取得良好的动态和稳态性能以及四象限运行特性,因而具有较好的应用价值.

  13. 非同步控制方式双管Buck-boost变换器减小反向恢复损耗的研究%Study on Reverse Recover Losses Reduction for Two-switch Buck-boost Converter with Coupling Inductor

    Institute of Scientific and Technical Information of China (English)

    杨晨; 谢少军; 秦岭

    2012-01-01

    A control mode of two-switch Buck-boost converter using the coupling inductor to reduce the diodes reverse recover losses was proposed. The operation principle was analyzed and the theoretical calculation was iUustrated. Finally, the simulation and experiment result shows that the proposed asynchronous control mode could not only reduce the diodes reverse recovery losses and the additional switch on losses, but also improve the converter efficiency further.%提出了采用耦合电感的双管Buck-boost变换器的一种非同步控制方式。讨论了采用耦合电感降低续流二极管反向恢复损耗的原理,对比分析了同步与非同步工作方式下电路的工作原理和电路中各电流的理论计算结果.并通过仿真和实验进行了验证。研究表明,与同步控制方式相比,所提出的非同步控制方式可以减小双管Buck-boost变换器续流二极管反向恢复损耗,可以进一步提升变换器效率。

  14. A Direct Power Control Scheme for Bi-directional Buck/Boost Converters in Motor Drive Systems%电机控制器直流侧前置双向Buck/Boost变换器的直接功率控制策略研究

    Institute of Scientific and Technical Information of China (English)

    张旭辉; 温旭辉; 赵峰

    2012-01-01

    The DC bus voltage fluctuation suppression in the motor drive system with a bi-directional Buck/Boost converter was studied. The disadvantage that the power feed-forward control scheme cannot effectively suppress bus voltage fluctuation was analyzed. A novel direct power control scheme with bus capacitor energy outer control loop and output power inner control loop for the bi-directional Buck/Boost converter was presented. Moreover, in order to improve the dynamic response of converters, a feed-forward term which reflects the changing trends of output power was added on its duty cycle calculation node. The essential difference between the above two control schemes was compared. Results and simulations of the small-signal model analysis and experimental results show the direct power control scheme has good performance in voltage fluctuation suppression.%对电机驱动系统前置双向Buck/Boost变换器后直流母线电压的波动抑制问题进行研究.分析功率前馈控制策略抑制母线电压波动能力较弱的原因.对双向Buck/Boost变换器提出一种母线电容能量外环、输出功率内环的直接功率控制策略,并将输出功率的变化趋势反映到双向Buck/Boost变换器的发波环节,进一步提高了变换器的动态响应特性.基于小信号模型分析上述两种控制策略的本质区别.小信号模型分析结果、仿真和实验结果都证实,提出的直接功率控制策略比功率前馈控制策略有更好的抑制母线电压波动的能力.

  15. 适合宽输入电压的单级升降压逆变器%A Single-stage Boost-Buck Inverter for Wide Range of Input Voltage

    Institute of Scientific and Technical Information of China (English)

    董仙美; 汤雨

    2013-01-01

    The output voltage range of PV cells is wide influenced by the environment, light, temperature and so on. The gird-connected inverters need to achieve voltage boost and inversion. Based on the structure of "virtual transformer", this paper presents a novel single-stage boost-buck inverter topology suitable for wide range input voltage, which can realize dc/ac and boost in single-stage power conversion. The "virtual transformer" with continuous ratio composed of high frequency power switch is proposed as a substitution for the traditional line frequency step-up transformer, which is in favor of the system with small volume, low weight and cost, easy integration and high efficiency. Analysis of the voltage buck and boost modes are presented followed by the implementation of the modulation strategy. Simulation and experimental results are presented to verify the proposed topology can achieve boost-buck inversion with wide range of input voltage.%光伏电池受环境、光照、温度等因素的影响,其输出电压范围宽,光伏并网逆变器需要完成逆变与升压两个功能.提出一种新型的适用于宽输入电压的单级式升降压逆变器拓扑,基于“虚拟变压器”的结构,在单级功率变换中实现逆变与升压的功能.采用高频的功率开关器件构成变比连续可调的虚拟升压变压器,替代传统笨重的工频升压变压器,使得逆变系统的体积、重量以及成本降低,易于集成,并且提高了变换效率.对该逆变器降压逆变与升压逆变的两种工作模式进行分析,给出调制策略的具体实现方案.仿真与实验结果表明,所提出的拓扑适合宽输入电压的升降压逆变场合.

  16. Collision Bifurcations and Chaos in Buck-Boost Converter with Ramp Compensation%具有斜坡补偿的Buck-Boost变换器的碰撞分岔现象及混沌

    Institute of Scientific and Technical Information of China (English)

    毕玉春; 汪小锋; 刘立生

    2010-01-01

    为了深入研究具有斜坡补偿的Buck-Boost变换器的碰撞分岔现象及混沌,导出了电流模式控制Buck-Boost变换器运行轨道转移时的两个边界方程,从而建立了具有两个边界的三段光滑非线性离散迭代二维映射方程,并通过数值仿真得到了输入电压、斜坡补偿电流的斜率和负载电阻R变化时的动力学行为分布图.

  17. 电流型Buck-Boost变换器的分岔频率相关性的验证%Verification of Frequency Correlation for Bifurcation of Current-Mode Controlled Buck-Boost Converters

    Institute of Scientific and Technical Information of China (English)

    李磊; 金爱娟; 李少龙

    2012-01-01

    PWM型Buck-Boost功率变换器的频标可用于预测不同频率运行下的第一个分岔点.本论文首先推导出功率变换器新型频率的相关性.这是在高频工作下由仿真实验结果验证得到的.

  18. Nonlinear Behavior Research of Current-Mode Controlled Buck-Boost Converters%电流模式控制Buck-Boost变换器非线性行为研究

    Institute of Scientific and Technical Information of China (English)

    谢玲玲; 龚仁喜; 王旷; 卓浩泽

    2010-01-01

    首先建立了电流反馈型Buck-Boost变换器在连续导电模式和不连续导电模式下的离散迭代数学模型,根据稳定性判据得出系统的稳定工作区域.在反馈系数K、输入电压V电感L等为分岔参数作用下,利用数值方法对Buck-Boost变换器中的非线性行为进行了详细的仿真研究.仿真研究和理论分析的结果吻合得很好,研究结果表明:Buck-Boost变换器在这两种工作模式下都是强非线性的,运行时会呈现出分岔、混沌等非线性现象.

  19. Modeling and Simulation of a Buck-Boost Converter Based on Injected-Absorbed-Current Method%基于注吸电流法的Buck-Boost变换器建模与仿真

    Institute of Scientific and Technical Information of China (English)

    李奇南; 凌跃胜

    2006-01-01

    该文详细介绍了注吸电流法的建模思想和步骤,并应用注吸电流法建立了工作在电感电流断续(DCM)模式下的Buck-Boost变换器数学模型.对Buck-Boost变换器及其PI调节器构成的闭环控制系统进行了分析研究.应用Simulink\\SimPowerSystem模块,建立了该系统的Matlab仿真模型,并进行了相应的仿真分析.仿真结果表明,所得Buck-Boost变换器数学模型的精确性和可用性可以满足要求,能够真实反映该系统的动、静态性能.满意的仿真结果与理论分析取得了一致,验证了该模型的正确性.

  20. 基于模型的Buck-Boost变换器协同无源控制%The Model-Based Synergetic and Passivity Control of Buck-Boost Converter

    Institute of Scientific and Technical Information of China (English)

    李红梅; 叶帮红

    2016-01-01

    为了改善Buck-Boost变换器的动态性能和静态性能,基于无源控制实现变换器电感电流期望值的实时观测,再与协同控制相结合得出控制律,提出了协同无源控制的Buck-Boost变换器实现其高性能控制并使之兼具强鲁棒性.为了简化控制器结构,选取协同控制宏变量时未引入积分环节,易于实时实现.最后,采用基于模型设计的开发流程和自动代码生成技术,开发协同无源控制的Buck-Boost变换器样机,通过系统的仿真研究和样机的实验测试,验证该变换器的动态和静态控制性能.

  1. Research on Control Strategy of Two-Switch Buck-Boost Converter for High Voltage Application%高输入电压双管Buck-Boost变换器控制策略研究

    Institute of Scientific and Technical Information of China (English)

    杨晨; 谢少军; 毛玲; 秦岭

    2014-01-01

    在较高输入电压应用场合,采用同步控制的双管Buck-Boost变换器存在较大的开关损耗,而单管工作的双管Buck-Boost变换器又存在复杂的升降压过渡控制问题.分析了一种含有耦合电感的双管Buck-Boost变换器,介绍了该变换器在同步控制模式下的工作模态以及耦合电感抑制反向恢复损耗及减小开关损耗的原理,给出了耦合电感的设计方法,并在此基础上提出一种非同步控制模式,可以进一步减小磁性元件损耗.在设计输入相同的条件下,对两种模式下变换器电路参数计算进行了理论推导和实验比较.研究结果表明,相比同步模式,非同步模式不仅可以实现利用耦合电感降低二极管反向恢复损耗的作用,还可以减小耦合电感等效电流脉动量从而减小磁心损耗.同时该非同步模式在变换器升、降压过渡过程中只对一个开关管进行占空比调节,可以较好地实现升降压平滑过渡.

  2. The PFC and Half-Bridge Output Circuit Based on Buck-Boost Converter%用Buck-Boost变换器实现PFC和半桥驱动输出

    Institute of Scientific and Technical Information of China (English)

    潘飞蹊; 陈星弼

    2003-01-01

    基于Buck-Boost变换器工作的基本原理,提出了一种功率因数校正(PFC)和半桥输出相结合的电路结构;并给出了相应的控制方式.理论分析求出了电感取值的边界条件.由于该电路能够实现降压输出,因而降低了对所有功率开关管的耐压要求.

  3. 无源无损软开关在Buck-Boost变换器中的应用%The Application of Passive Lossless Soft-switch in Buck-Boost Converters

    Institute of Scientific and Technical Information of China (English)

    赵玉峰; 崔文君; 王旭

    2010-01-01

    详细分析一种基于Buck-Boost变换器的无源无损电路单元,仅通过在变换器中附加一些无源元件实现了开关管的零电流导通和零电压关断,并将缓冲元件的能量回馈给变换器的输入输出端,达到了无损的效果.示出最优参数的方法,而且相比有源电路,该缓冲电路单元结构简单、控制方便、可靠性更高,并能在软开关的情况下保持开关管的最小电压应力,并与传统的Buck-Boost变换器进行比较,验证其具有更高的效率.

  4. 不连续运行模式电流型Buck-Boost变换器中的分岔和混沌%Bifurcation and Chaos from a Current-Programmed Buck-Boost Converter Operating in Discontinuous Mode

    Institute of Scientific and Technical Information of China (English)

    李小峰; 戴栋; 马西奎

    2003-01-01

    在不连续运行模式条件下,建立了分析电流反馈型Buck-Boost变换器中的分岔行为和混沌过程的分段离散迭代映射方程,得到了以输入电压E为参数的分岔图和相图.数值结果表明,工作于不连续模式下的电流反馈型Buck-Boost变换器会出现特有的一些非光滑分岔现象.例如,与光滑系统中典型的倍周期分岔不同的是,在周期1到周期2的倍周期分岔点附近,周期2轨道分枝不垂直于周期1轨道分枝,并且直接经周期6到达混沌态.

  5. 用于光伏并网的交错型双管Buck-Boost变换器%An Interleaving Double-switch Buck-Boost Converter for PV Grid-connected Inverter

    Institute of Scientific and Technical Information of China (English)

    肖华锋; 谢少军

    2010-01-01

    双管Buck-Boost变换器拥有输入输出电压同极性和可升降压等特性,适合于两级式光伏并网逆变器中前级直流变换,但其同步开关方式需要较大的储能电感,且组合式开关方式控制电路复杂、实现工作模式无缝切换较困难.提出一种交错开关型双管Buck-Boost变换器,可使储能电感最小、控制电路简单,并实现无工作模式切换.分析了该变换器的工作原理和特性,比较3种开关方式下几个主要特性的优劣.最后通过一台3kW两级式并网逆变器,验证了所提变换器工作原理的正确性.

  6. Research of an active Buck-Boost Inverter Under Dual Mode Modulation%有源升降压逆变器双模式调制策略研究

    Institute of Scientific and Technical Information of China (English)

    何耀华; 汤雨; 董仙美

    2014-01-01

    The inverter used in new energy power generation system should have the ability to adapt a wide range of DC input voltage. Based on the active buck-boost inverter which consists of a full bridge and Boost AC/AC part, two modulation methods were compared: constant boost ratio modulation and dual mode modulation. Along with the relationship of the input DC voltage and the reference AC voltage, the converter completes buck or boost inversion with different equivalent circuits and there are fewer switches working at high frequency in dual mode modulation, which is in favor of the system with high efficiency. The current of the inductor and the current stress of the switches was analyzed in this paper. Experimental results were presented to verify that the proposed topology can achieve dual mode operation with wide range of input voltage.%新能源发电系统要求逆变器具有宽输入电压适应能力,该文基于有源升降压逆变器拓扑,对恒升压比调制和双模态调制两种调制方法进行对比。双模态调制根据不同的直流输入与瞬时的交流输出电压大小关系,使电路呈现出不同的等效电路结构,且每种结构均只有部分开关管高频工作,有利于提高变换效率。还对两种调制下电感电流、开关管电流应力进行分析比较。实验结果表明,该变换器可双模式工作,具有宽输入电压适应能力。

  7. A Robust High Order Sliding Mode for Buck-Boost Converters With Large Disturbances%大扰动Buck-Boost变换器的鲁棒高阶滑模控制

    Institute of Scientific and Technical Information of China (English)

    吴宇; 皇甫宜耿; 张琳; 周雒维

    2015-01-01

    在利用诸如风、光、氢等随机性新能源发电的过程中,由于间歇性的能量输入和不断变化的输出负载等原因,对电源变换器的鲁棒性设计提出了更高的要求.针对传统滑模控制变换器自身存在不可避免的抖颤问题,该文基于一种Super-Twisting高阶滑模控制算法,设计了以TMS320F28035为控制核心的无抖颤、强鲁棒滑模电源变换器.并以Buck-Boost变换器为例,针对随机性新能源发电中输入输出端存在的大扰动问题,与增量式PI控制效果进行对比实验.实验结果表明:高阶滑模控制变换器在输出负载大扰动下具有很强的鲁棒性;高阶滑模控制变换器在输入电压大扰动下同样具有很强的鲁棒性.

  8. The Control Mode of Distribution Grid/Off-Grid of Wind-Solar-Storage with Double Boost-Buck Converter Single Inverter Based on V2 Control Method%基于V2控制方法双Boost-Buck单一逆变器的风光储分布并网/孤岛离网控制模式

    Institute of Scientific and Technical Information of China (English)

    希望·阿不都瓦依提; 晁勤; 王筱

    2016-01-01

    目前边缘农牧区采用风光互补发电,由于通过各自逆变器运行,存在成本高、能耗高等问题。提出采用双Boost-Buck单一逆变器结构实现风光储联合发电共用直流母线方案,达到降低投资成本和运行能耗的效果。首先设计了基于 V2控制双 Boost-Buck 变换器风光储联合发电的拓扑结构和电路,实现了输入电压在较宽范围内波动时输出电压仍然能够恒值控制的目标,同时采用电压斜坡补偿方法抑制了Boost-Buck电路自激振荡问题。接着基于蓄电池,制定了储能平抑风光波动、九宫分区跟随负荷、模糊充放电等控制策略,达到了风光储发电与逆变器无缝对接。其次基于风光储联合发电系统,进行了减小弃风光电量效益评估。最后基于风光储分布并网和孤岛离网控制模式,研发了软硬件装置,进行了仿真验证和试验测试。结果表明:逆变器输出电流具有良好的静、动态性能,同时实现了较好的经济性、有效性、稳定性和可靠性。%Wind and solar hybrid power generation is widely used in agricultural and pastoral areas. In current applications, each system uses independent inverters, which requires higher cost and energy consumption. In this paper, a common DC bus scheme with dual Boost-Buck based single inverter structure was proposed, to realize wind and solar hybrid power generation. The proposed scheme can reduce cost and energy consumption. Firstly, topological structure and circuit of wind-solar-storage cogeneration system were designed based on V2 controlled double Boost-Buck converter. Hence the constant voltage value control can be achieved when the input voltage varies in a wide range. At the same time, voltage slope compensation method was used to suppress the self-excited oscillation of Boost-Buck circuit. Secondly, a series of control strategies were designed to improve storage stability, including stabilizing

  9. 双向全桥DC/DC转换器升降压控制系统的设计与实现%Design and realization of Boost-Buck control system for bidirectional full-bridge DC/DC converter

    Institute of Scientific and Technical Information of China (English)

    李宏恩; 周晋阳; 申玉坤

    2016-01-01

    双向DC/DC转换器是实现高低压电能双向传输功能的直流转换器,在各种直流稳压电源设计上应用广泛。通过小信号分析法,将非线性的DC/DC转换器变换为线性的数学模型进行研究,确定了全桥DC/DC转换器在升/降压模式下的传递函数,然后通过离散型PID控制算法,分析了系统控制的稳定性并确定了PID参数,设计了转换器补偿网络。最后通过仿真模型和样机实验验证,证明了双向全桥DC/DC转换器的升/降压控制系统的有效性。%The bidirectional DC/DC converter can realize the high voltage and low voltage bidirectional conversion,and is widely used in the design of various DC voltage⁃stabilized power supply. The nonlinear DC/DC converter is transformed into the linear mathematical model by means of the small signal analysis method for study. The transfer functions of full⁃bridge DC/DC converter in Boost/Buck modes are determined. And then the discrete PID control algorithm is used to analyze the stability of the control system and determine the PID parameters. The compensation network of the converter was designed. The simulation model and prototype experiment were verified,and the results show that the Boost⁃Buck control system of the bidirectional full⁃bridge DC/DC converter is effective.

  10. A Dual-Buck–Boost AC/DC Converter for DC Nanogrid With Three Terminal Outputs

    DEFF Research Database (Denmark)

    Wu, Weimin; Wang, Houqing; Liu, Yuan

    2017-01-01

    such as the low-voltage ac power system. There are three typical grounding configurations for a dc nanogrid: the united grounding, the unidirectional grounding, and the virtual isolated grounding. Each grounding configuration has its own specifications to ac/dc converters. In this paper, a dual-buck-boost ac...

  11. Single phase AC-DC power factor corrected converter with high frequency isolation using buck converter

    Directory of Open Access Journals (Sweden)

    R. Ramesh,

    2014-03-01

    Full Text Available Single phase ac-dc converters having high frequency isolation are implemented in buck, boost, buck-boost configuration with improving the power quality in terms of reducing the harmonics of input current. The paperpropose the circuit configuration, control mechanism, and simulation result for the single phase ac-dc converter.

  12. Diseño y simulación de un balastro electrónico con corrección de factor de potencia con topología buck-boost e inversor alimentado por corriente

    Directory of Open Access Journals (Sweden)

    Germán E. Melo

    2014-08-01

    Full Text Available Las lámparas fluorescentes compactas o CFL (compact fluorescent lamp se han convertido en uno de los tipos de iluminación más usados en la actualidad. Sin embargo, las CFL comerciales poseen en su mayoría balastros electrónicos de bajo factor de potencia. Esto genera un aumento en los niveles de distorsión del sistema de generación y distribución debido al uso masivo de estas lámparas. En el presente artículo se presenta el diseño y simulación de un balastro electrónico con corrección de factor de potencia para lámparas fluorescentes compactas. La propuesta busca evaluar la viabilidad de integrar el correcto funcionamiento, tamaño y costo de este dispositivo. La topología propuesta es una etapa buck-boost operando en modo de conducción discontinua integrada a un inversor alimentado por corriente. La alta factibilidad de implementación de esta topología es mostrada mediante simulaciones que logran un factor de potencia de 0.998 y una distorsión total armónica menor de 5 %.

  13. Diseño y simulación de un balastro electrónico con corrección de factor de potencia con topología buck-boost e inversor alimentado por corriente

    Directory of Open Access Journals (Sweden)

    Germán E. Melo

    2014-05-01

    Full Text Available Las lámparas fluorescentes compactas o CFL (compact fluorescent lamp se han convertido en uno de los tipos de iluminación más usados en la actualidad. Sin embargo, las CFL comerciales poseen en su mayoría balastros electrónicos de bajo factor de potencia. Esto genera un aumento en los niveles de distorsión del sistema de generación y distribución debido al uso masivo de estas lámparas. En el presente artículo se presenta el diseño y simulación de un balastro electrónico con corrección de factor de potencia para lámparas fluorescentes compactas. La propuesta busca evaluar la viabilidad de integrar el correcto funcionamiento, tamaño y costo de este dispositivo. La topología propuesta es una etapa buck-boost operando en modo de conducción discontinua integrada a un inversor alimentado por corriente. La alta factibilidad de implementación de esta topología es mostrada mediante simulaciones que logran un factor de potencia de 0.998 y una distorsión total armónica menor de 5 %.

  14. A Non-isolated Bidirectional Three-port Buck-Boost Converter%一种非隔离双向三端口升降压变换器

    Institute of Scientific and Technical Information of China (English)

    张君君; 吴红飞; 曹锋; 朱励厉; 邢岩

    2014-01-01

    A non-isolated three-port bidirectional DC-DC converter and its power control were proposed. The converter was derived from three bidirectional Buck/Boost switching cells cascaded with each other with DC-link capacitor removed. Compared with conventional solution of multiple bidirectional converters connected with a shared common DC bus, the proposed converter has the advantage of reduced size, lower cost and better reliability from DC-link capacitor eliminated, and it also greatly improved the efficiency and power density from single-stage step-up/-down conversion between any two of the multiple ports. The operational principles were analyzed in detail with power control and PWM strategy given. Finally, the topology and analysis were verified with the experimental results.%提出一种非隔离双向三端口升降压变换器拓扑及其功率控制策略。该变换器由3个双向Buck/Boost开关单元不通过直流母线电容级联组合而成;相对于传统多个变换器通过公共直流母线连接的解决方案,该变换器完全消除了中间母线电容,可减小变换器体积、重量和成本,提高系统可靠性,且任意两个端口之间均为单级升降压变换,大大提高了变换器的变换效率和功率密度。详细分析变换器的工作原理,给出相应的脉宽调制(pulse width modulation,PWM)和功率控制策略,最后通过实验验证理论分析的正确性。

  15. Research on a Three-Phase DC/AC Inverter Based on Buck-Boost Circuit%基于升降压斩波电路的三相DC/AC逆变器研究

    Institute of Scientific and Technical Information of China (English)

    陈荣

    2013-01-01

    In order to solve the problems brought about by the common inverter,we propose a novel three-phase DC/AC inverter topology based on buck-boost circuit,and describes how it works.The implementation method applied for three-phase DC/AC inverter using single phase inverter is given.The single-phase inverter and threephase inverter are studied using PSIM software.The parameters adopted in the realistic simulation,waveforms such as load current,voltage of modulation reference and load were given.The simulation results proved that adopting the three-phase DC/AC inverter could achieve a good performance with wide input voltage range and the output voltage of it can gain a line frequency as 50 Hz and the correctness of theoretical analysis.%为了解决常用的逆变器所带来的问题,我们提出一种新型的带升降压功能的三相DC/AC变换器拓扑,并介绍了其工作原理.借助于PSIM仿真软件,对单相和三相电路进行了仿真研究,提出了由单相组成三相电压输出的构成方法.在列出仿真参数的前提下,给出了负载电压,负载电流以及调制给定电压和逆变器输出电压的仿真结果.仿真结果表明三相DC/AC逆变器可以实现50 kHz高频功率变换下宽输入电压范围工频逆变输出,证明了理论分析的正确性.

  16. 采用组合控制方案的双管升/降压变换器%Two-switch Boost-Buck converter with integrated control scheme

    Institute of Scientific and Technical Information of China (English)

    毛鹏; 童瑞婷

    2014-01-01

    分析了现有单相级联型Boost-Buck功率因数校正变换器的控制原理,并指出了其存在的不足,在此基础上提出一种新型组合控制方案.该方案在Boost工作模式下采用平均电流控制,在Buck工作模式下采用电荷控制.新型控制方案可以确保变换器不论在升压还是降压工作模式期间,都可实现良好的输入电流控制效果,达到功率因数校正的目的.通过原理样机实验,对理论分析的正确性和控制方案的有效性进行了验证.

  17. 开关电容boost-buck功率因数校正组合开关变换器%A Switched Capacitor Based Boost-Buck Power Factor Correction Integrated Switching Converter

    Institute of Scientific and Technical Information of China (English)

    程红丽

    2001-01-01

    文章提出了一种基于开关电容网络的boost-buck组合开关变换器,当其输入环节工作在不连续导电模式(DCM)时,具有功率因数校正(PFC)功能。详细分析了这类变换器的工作原理、临界条件、输入输出电压变比以及各器件的应力。实验结果与理论分析相符。

  18. MATLAB下利用BUCK-BOOST变换器实现通信电源功率因数校正的仿真分析%The power factor correction analysis of communication power supply by using MATLAB-based BUCK-BOOST converter

    Institute of Scientific and Technical Information of China (English)

    刘宇

    2004-01-01

    详细分析了用BUCK-BOOST实现电路功率因数校正的原理和变换过程,并给出了BUCK-BOOST电路的Matlab仿真分析的模型.通过对变换器工作在DCM模式下的电路仿真,验证了此方法的良好效果.

  19. 基于四管同步升降压变换器汽车适配器设计%Automotive Adaptor based on Four Switchers Synchro Buck-Boost Converter

    Institute of Scientific and Technical Information of China (English)

    刘松

    2007-01-01

    讨论了四管同步Buck-Boost升降压变换器的工作原理.这种变换器有同步降压Buck、降升压Buck-Boost、同步升压Boost三种工作模式.详细分析了输入和输出接近相等时,四管同步降压及升压Buck-Boost模式的工作原理.降压Buck-Boost模式中电感先深去磁,再短时间的深激磁,然后长时间的浅激磁;升压Buck-Boost模式中电感先深激磁,再短时间的深去磁,然后长时间的浅去磁,从而维持低纹波的输出电压调节.还介绍了具有12V/24V通用电池电压输入范围的汽车电池适配器的设计过程,讨论了电感的计算和选取方法,以及PCB的设计原则.

  20. Simple buck/boost voltage regulator

    Science.gov (United States)

    Paulkovich, J.; Rodriguez, G. E.

    1980-01-01

    Circuit corrects low or high supply voltage, produces regulated output voltage. Circuit has fewer components because inductory/transformer combination and pulse-width modulator serve double duty. Regulator handles input voltage variation from as low as one half output voltage to as high as input transistor rating. Solar arrays, fuel cells, and thermionic generators might use this regulator.

  1. Modeling Method of Parameters Designing in Wind Power Generating According to Dynamics Behaviours of the Buck-Boost Converter%风力发电中Buck-Boost变换器参数设计的动力学建模方法

    Institute of Scientific and Technical Information of China (English)

    王立国; 徐殿国; 张华强; 苗立杰; 郎永强

    2005-01-01

    以DC-DC Buck-Boost开关变换器在变速恒频风力发电中的实际应用为研究背景,给出了对Buck-Boost变换器进行动力学建模与应用经典电路分析相结合的变换器母线电容参数设计方法.首先基于Buck-Boost变换器拓扑结构建立精确的数学模型,再根据此模型参数摄动的动力学仿真来判断应用经典电路分析法所获得的变换器参数的可行性,进而给出合理的参数取值.仿真与实验结果验证了所提出的Buck-Boost变换器参数设计方法的正确性.

  2. Modeling and Analysis of Buck/Boost Bidirectional DC/DC Converter with Developed PWM Switch Model%基于发展的PWM Switch模型的Buck/Boost双向直直变换器建模及分析

    Institute of Scientific and Technical Information of China (English)

    王建华; 张方华; 龚春英

    2014-01-01

    提出了双向功率流动场合的PWM Switch模型,同时选取典型的Buck/Boost双向变换器作为评估平台.小信号分析结果表明,Buck/Boost双向直直变换器通过仅控制Buck模式主控管可以对电池充放电模式进行切换.其提供了对变换器稳态及动态性能研究的一种快速仿真方法.基于改进PWM Switch模型及器件级电路的详尽仿真对比验证了模型的精确性.

  3. Controlled doe exposure as biostimulation of buck rabbits.

    Science.gov (United States)

    Rodríguez-De Lara, R; Noguez-Estrada, J; Rangel-Santos, R; García-Muñiz, J G; Martínez-Hernández, P A; Fallas-López, M; Maldonado-Siman, E

    2010-12-01

    Female exposure of males could be a low-cost biostimulation option that benefits AI in commercial rabbit operations by improving buck rabbits reproductive performance. The objective of the study was to evaluate exposure of buck rabbits to females as a biostimulation option to improve reproductive potential. Treatments were: exposure (biostimulated) or not (control) of bucks to does. Bucks were New Zealand White, 15-month-old, sexually experienced and fertile. Experimental design was completely random with nine replications, experimental unit was one buck. Doe exposure was permanent using replacement pubertal does housed in an adjacent wire-mesh cage and changed for new ones every other week. Semen collection lasted 14 weeks (late winter and early spring) twice a week with two ejaculates at each collection. Analyses of variance were under a mixed model: treatments, ejaculate number and season were fixed and rabbit random effects and buck weight at each collection as covariable. Biostimulated bucks showed greater (Pbucks but not in doe exposed bucks (treatment × ejaculate number, Pbuck rabbits. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Primary Paralleled Isolated Boost Converter with Extended Operating Voltage Range

    DEFF Research Database (Denmark)

    Hernandez Botella, Juan Carlos; Sen, Gökhan; Mira Albert, Maria del Carmen

    2012-01-01

    Applications requiring wide input and output voltage range cannot often be satisfied by using buck or boost derived topologies. Primary paralleled isolated boost converter (PPIBC) [1]-[2] is a high efficiency boost derived topology. This paper proposes a new operation mode for extending the input...

  5. Eugenics Past and Present: Remembering Buck v. Bell.

    Science.gov (United States)

    Berson, Michael J.; Cruz, Barbara

    2001-01-01

    Provides background information about the eugenics movement. Focuses on eugenics in the United States detailing the case, Buck v. Bell, and eugenics in Germany. Explores the present eugenic movement, focusing on "The Bell Curve," China's one child policy, and the use of eugenic sterilizations in the United States and Canada. Includes…

  6. multilevel buck converter for automotive electrical load

    African Journals Online (AJOL)

    user

    development of DCM based buck converter and its applications in the HEVs/EVs using ... The paper also highlights the implications of implementing a single stage buck converter, and ..... instance when the saw tooth signal within the internal.

  7. 一种快速响应高效多模式升压降压型转换器%Rapidly transient response with the flexible mode and high-efficiency buck-boost converter

    Institute of Scientific and Technical Information of China (English)

    成立业; 来新泉

    2016-01-01

    A novel current sensing technique with a rapidly transient and flexible mode buck‐boost converter is presented . The converter can work in an appropriate mode according to the input voltage ( VIN ) and inductor current ( IL ) , with smooth transition and flexible working modes achieved . The average current sensing ( AVCS ) circuit has an accurate measurement of IL . The transient response time is also decreased . The current sensing converter is implemented in the Silterra 0.18μm COMS process . Experimental results show 95% peak efficiency at an output current 1 A with 4.2 V VIN , so that the converter can extend the battery life . The output transient with the load current altering from 0 to 2 A is 6 mV and the recovery time is 60μs .%描述了一种新颖的高效多工作模式可快速响应的电流模升压降压型转换器.转换器有灵活的工作模式,电路可以根据输入电压和电感电流的变化来选择工作模式,并且各种工作模式可以平稳转换.平均电流感应模块可以很精确地量测出电感电流.负载瞬态响应时间较其他转换器有降低.这款电流模转换器使用Silterra 0.18μm CMOS工艺流片.实验结果显示,在4.2 V输入电压、1 A负载电流条件下,转换器的最大效率达95%,因此,使用该转换器可以延长供电电池使用寿命.输出从空载到2 A切换时,输出电压变化为6 m V ,恢复时间为60μs .

  8. Bucking Trends: Expanding the Arts

    Science.gov (United States)

    Levin, Kathi R.

    2008-01-01

    The arts and music have been unintended victims of the No Child Left Behind Act. Several reports point to sharp reductions in student access to K-12 arts education, yet some school districts nationwide have managed to buck the trend. These districts, in communities rural through urban, are systemically embedding the arts at the core of teaching…

  9. Diode-assisted buck-boost voltage source inverters

    DEFF Research Database (Denmark)

    Gao, F.; Loh, P.C.; Teodorescu, Remus

    2007-01-01

    charging and discharging processes of passive components reveals that the dc-link voltage can alternate between two levels, which therefore demonstrate the phenomena that the specified modulation schemes should note. A modulation scheme that can achieve optimized harmonic switching is first designed...... with symmetrical state placement in each switching sequence to avoid unnecessary voltage stress across both passive and active components. To reduce the total commutation count, the designed modulation scheme is then modified without increasing voltage stress. All theoretical findings were verified experimentally...... using a number of scale-down laboratory prototypes....

  10. Advanced In-Space Propulsion (AISP): High Temperature Boost Power Processing Unit (PPU) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The task is to investigate the technology path to develop a 10kW modular Silicon Carbide (SiC) based power processing unit (PPU). The PPU utilizes the high...

  11. Conference James F.Buckli

    CERN Multimedia

    Buckli,J

    1988-01-01

    L'association du personnel a le plaisir d'accueillir Mons. James F.Buckli, astronaute, né en 1947. Il a participé à la mission Space Lab D1 qui pour la première fois mettait 8 personnes sur orbite.L'ass.du pers. remercie aussi Gordon White(s) de la mission américaine d'avoir permis d'organiser cette conférence

  12. Sandy Point, Green Cay and Buck Island National Wildlife Refuges: United States Virgin Islands, Caribbean Islands National Wildlife Refuge Complex: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on United States Virgin Islands, Caribbean Islands NWR Complex for the next 15 years. This...

  13. Studies of Interleaved DC-DC Boost Converters with Coupled Inductors

    Science.gov (United States)

    2011-04-01

    power density requirements, interleaved buck and boost converters have been studied in recent years for their potential to improve power converter ...duty ratio of switch S1. Figure 1: Conventional DC-DC Boost Converter Topology (1) Vout/Vin...interleaved DC-DC boost converters with coupled inductors. Included are discussions on a 10kW prototype, a 2kW high temperature prototype, and two 2kW

  14. Long-Term Reliability of a Hard-Switched Boost Power Processing Unit Utilizing SiC Power MOSFETs

    Science.gov (United States)

    Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Iannello, Christopher J.; Del Castillo, Linda Y.; Fitzpatrick, Fred D.; Mojarradi, Mohammad M.; Chen, Yuan

    2016-01-01

    Silicon carbide (SiC) power devices have demonstrated many performance advantages over their silicon (Si) counterparts. As the inherent material limitations of Si devices are being swiftly realized, wide-band-gap (WBG) materials such as SiC have become increasingly attractive for high power applications. In particular, SiC power metal oxide semiconductor field effect transistors' (MOSFETs) high breakdown field tolerance, superior thermal conductivity and low-resistivity drift regions make these devices an excellent candidate for power dense, low loss, high frequency switching applications in extreme environment conditions. In this paper, a novel power processing unit (PPU) architecture is proposed utilizing commercially available 4H-SiC power MOSFETs from CREE Inc. A multiphase straight boost converter topology is implemented to supply up to 10 kilowatts full-scale. High Temperature Gate Bias (HTGB) and High Temperature Reverse Bias (HTRB) characterization is performed to evaluate the long-term reliability of both the gate oxide and the body diode of the SiC components. Finally, susceptibility of the CREE SiC MOSFETs to damaging effects from heavy-ion radiation representative of the on-orbit galactic cosmic ray environment are explored. The results provide the baseline performance metrics of operation as well as demonstrate the feasibility of a hard-switched PPU in harsh environments.

  15. Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

    Science.gov (United States)

    Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

    2016-01-01

    Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

  16. Average and Small Signal Modeling of Negative-Output KY Boost Converter in CCM Operation

    Directory of Open Access Journals (Sweden)

    Faqiang Wang

    2014-01-01

    Full Text Available Negative-output KY Boost converter, which can obtain the negative output voltage and could be driven easily, is a good topology to overcome traditional Boost and Buck-Boost converters and it is believed that this converter will be widely used in engineering applications in the future. In this study, by using the averaging method and geometrical technique, the average and small signal model of the negative-output KY Boost converter are established. The DC equilibrium point and transfer functions of the system are derived and analyzed. Finally, the effectiveness of the established model and the correctness of the theoretical analysis are confirmed by the circuit experiment.

  17. Stability analysis of a buck regulator employing input filter compensation

    Science.gov (United States)

    Kelkar, S. S.; Lee, F. C.

    1983-01-01

    The interaction between the input filter and the regulator often causes serious degradation of performance. The reduction in loop gain due to input filter interaction can result in system instability. An exact stability analysis of the buck regulator system is presented. The input filter parameter values are varied and system instability is predicted for the case without feedforward. The eigenvalues of the system can be brought back into the unit circle and the system thus stabilized with the addition of the feedforward loop. Measurements made for the cases with and without feedforward confirm the analytical prediction.

  18. Sediment magnetic and paleomagnetic data from Buck Lake, Oregon

    Science.gov (United States)

    Rosenbaum, J.G.; Reynolds, R.L.; Fitzmaurice, P.L.; Drexler, J.W.; Whitney, C.G.; Adam, D.P.

    1994-01-01

    Sediment magnetic and paleomagnetic studies were conducted on a core from Buck Lake, Klamath County, Oregon, that was collected as part of an investigation into the Quaternary climate history of the western United States. This report documents the methods used to obtain paleomagnetic directions, magnetic properties, and ancillary data, and presents these data in tabular form. Adam (1993) and Adam and others (1994) describe the site, the drilling methods, and lithology of the lacustrine sediments. Rosenbaum and others (1994) present preliminary interpretations of the sediment magnetic data and show that variations in magnetic properties closely reflect changes in climate as interpreted from the pollen record.

  19. Scalar Controlled Boost PWM Rectifier for Micro Wind Energy Systems

    Directory of Open Access Journals (Sweden)

    J. Chelladurai

    2015-05-01

    Full Text Available Uses of Permanent Magnet Synchronous Generators (PMSG are increasing in variable speed micro-Wind Energy Conversion Systems (WECS. In stand-alone or grid-connected Micro-WECS, extraction of maximum power is vital. To extract maximum power output and to obtain a constant DC bus voltage from variable magnitude and variable frequency voltage output of PMSG and generally a two stage scheme namely i conventional diode bridge rectifier and ii DC-DC Boost/Buck/Buck-Boost converters are used. In this study, a single stage Scalar Controlled PWM (SCPWM Boost Rectifier is proposed in order to minimize the current harmonics and to improve the power factor on source side. The modeling and simulation of PMSG based wind generator and SCPWM Boost rectifier was developed in MATLAB. The harmonic content in the input current waveform of the proposed SCPWM rectifier is compared with the conventional three-phase bridge rectifier. The Simulation results show the effectiveness of the PWM Boost rectifier in terms of effective utilization of source, improved efficiency and harmonic mitigation for PMSG based Wind Generator. Simulation results demonstrate the effectiveness of the proposed system in reducing the current and voltage THD on source side.

  20. SPECTRAL ANALYSIS OF BUCK AND SEPIC CONVERTERS

    Directory of Open Access Journals (Sweden)

    CHAKIB ALAOUI

    2011-02-01

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

  1. Comparison of Conventional Converter with Three-Phase SingleStage Ac-Dc PWM Buck-Type Full-Bridge Converter

    Directory of Open Access Journals (Sweden)

    P. Gopal,

    2015-11-01

    Full Text Available The main objective of this concept is to examine the operation of fundamental buck-based three-phase singlestage ac–dc full-bridge converters. In this concept, the operation of this fundamental converter is explained and analyzed, and a procedure for the design of its key components is derived and demonstrated with an example and general concluding remarks comparing Buck-Based and Boost Based three Phase single-stage AC to DC full Bridge converters are made.

  2. Simulation of Multi output Fly back Converter with Integrated Auxiliary Buck Converter with reduced components

    Directory of Open Access Journals (Sweden)

    J.KOMATHI

    2015-04-01

    Full Text Available The fly back converter has been widely used for multi outputs due to the simple structure and low cost in low-power applications. This paper presents a new multi output converter. It consists of a half-bridge inverter with boost converter in primary side and a fly back rectifier that is integrated with an auxiliary buck converter in secondary side. The boost converter is used to generate high voltage dc from Low voltage PV cells. The primary switches control the main output voltage and the secondary synchronous switches control the auxiliary output voltage. The main advantages of the proposed converter are that the transformer size can be reduced due to the less magnetizing offset current, all the power switches including synchronous ones can achieve the zero-voltage switching (ZVS and it has no output cross regulation problems. The circuit is simulated using MATLAB. The performance is verified with simulation results.

  3. Women in History--Pearl Buck: An Advocate for Women and Children

    Science.gov (United States)

    Watts, Lynette

    2008-01-01

    This article profiles Pearl Buck, an advocate for women's rights and minority children, an author of Chinese history, and a pioneer in many ways. Buck established the Welcome House in 1949 in order to help unadoptable children find families (Conn, 1996). In 1964, Buck founded the Pearl S. Buck Foundation, now Pearl S. Buck International, which…

  4. Women in History--Pearl Buck: An Advocate for Women and Children

    Science.gov (United States)

    Watts, Lynette

    2008-01-01

    This article profiles Pearl Buck, an advocate for women's rights and minority children, an author of Chinese history, and a pioneer in many ways. Buck established the Welcome House in 1949 in order to help unadoptable children find families (Conn, 1996). In 1964, Buck founded the Pearl S. Buck Foundation, now Pearl S. Buck International, which…

  5. Aalborg Inverter - A New Type of “Buck in Buck, Boost in Boost” Grid-Tied Inverter

    DEFF Research Database (Denmark)

    Wu, Weimin; Ji, Junhao; Blaabjerg, Frede

    2015-01-01

    of the filtering inductor in the power loop is achieved to reduce the conduction power loss in both “boost” and “buck” mode. The principle of operation is demonstrated through the analysis on the equivalent circuits of a “half-bridge” single-phase inverter. The theoretical analysis shows that when input dc voltage...

  6. Aalborg Inverter - A new type of “Buck in Buck, Boost in Boost” Grid-tied Inverter

    DEFF Research Database (Denmark)

    Wu, Weimin; Blaabjerg, Frede

    2013-01-01

    , the minimum filtering inductance in the power loop is achieved to reduce the conduction power loss whether in “Boost” or “Buck” mode. In theory, it can achieve higher efficiency than other inverters under the same condition of input DC voltage. The principle of operation is fully illustrated through...

  7. A Novel High-power Input-parallel Output-series Buck-halfbridge Converter%一种新型大功率输入并联输出串联Buck半桥变换器

    Institute of Scientific and Technical Information of China (English)

    杜青; 齐铂金; 张涛; 汪涛

    2012-01-01

    现有的升降压拓扑中双管Buck-Boost和双管Boost-Buck变换器较符合高效大功率场合的使用要求,前者结构简单,但电流纹波大;后者引入了2个电感,功率密度很难提高。提出了一种新型大功率并联输出串联Buck半桥变换器(input-parallel output-series Buck-halfbridge,IPOSBHB),分析了IPOSBHB的电路结构、工作原理及基本关系,并从电压电流应力、磁性元件总体积、效率这3个方面与双管Boost-Buck变换器做了对比,提出了一种基于组合开关方式的控制策略,实现了升降压的模式切换和恒压、恒流的输出特性,最后通过1台15 kW样机对所提出的理论进行了验证。%Two-switch Buck-Boost and Boost-Buck converter are the most appropriate solutions for efficient high-power applications in existing topologies.The former structure is simple,whereas the current ripple is large.The latter introduces two inductors,thus the power density is difficult to improve.A novel high-power input-parallel output-series Buck-halfbridge(IPOSBHB) converter was proposed in this paper.The circuit structure,working principle and basic relations were analyzed.A comparison of IPOSBHB and Boost-Buck cascade converter was also elaborated including voltage and current stress,the total volume of magnetic components and efficiency.A combinatorial control strategy was proposed,thereby the Buck-Boost operation mode transition and constant voltage and current output characteristics were realized.The proposed theory is validated by a 15 kW prototype.

  8. SelfieBoost: A Boosting Algorithm for Deep Learning

    OpenAIRE

    2014-01-01

    We describe and analyze a new boosting algorithm for deep learning called SelfieBoost. Unlike other boosting algorithms, like AdaBoost, which construct ensembles of classifiers, SelfieBoost boosts the accuracy of a single network. We prove a $\\log(1/\\epsilon)$ convergence rate for SelfieBoost under some "SGD success" assumption which seems to hold in practice.

  9. SelfieBoost: A Boosting Algorithm for Deep Learning

    OpenAIRE

    Shalev-Shwartz, Shai

    2014-01-01

    We describe and analyze a new boosting algorithm for deep learning called SelfieBoost. Unlike other boosting algorithms, like AdaBoost, which construct ensembles of classifiers, SelfieBoost boosts the accuracy of a single network. We prove a $\\log(1/\\epsilon)$ convergence rate for SelfieBoost under some "SGD success" assumption which seems to hold in practice.

  10. 36 CFR 7.73 - Buck Island Reef National Monument.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Buck Island Reef National Monument. 7.73 Section 7.73 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.73 Buck Island Reef National Monument...

  11. Accelerated commutation for passive clamp isolated boost converters

    OpenAIRE

    2002-01-01

    An efficient and cost effective bidirectional DC/DC converter reduces switch voltage stress via accelerated commutation allowing use of a low-cost passive clamp circuit in boost mode. The converter includes a primary circuit, transformer and secondary circuit. The primary circuit takes the form of a “full bridge converter,” a “push-pull converter,” or an “L-type converter.”. The primary circuit may include a dissipator such as a snubber circuit or small buck converter. A secondary side of the...

  12. Boosting Culture

    Institute of Scientific and Technical Information of China (English)

    ZHOU JIANXIONG

    2011-01-01

    Culture makes up an indispensable part of our lives,just like material comfort.It is thought of as an important source of a nation's vitality and creativity,and constitutes a key factor uniting the nation,while making it distinctive from other countries.It is also said culture is a productive power that not only shapes human concepts and impacts their behavior,but also contributes in no small measure to the betterment of our material as well as spiritual world.

  13. Integrated mixed signal control IC for 500-kHz switching frequency buck regulator

    Science.gov (United States)

    Chen, Keng; Zhang, Hong

    2015-12-01

    The main purpose for this work is to study the challenges of designing a digital buck regulator using pipelined analog to digital converter (ADC). Although pipelined ADC can achieve high sampling speed, it will introduce additional phase lag to the buck circuit. Along with the latency brought by processing time of additional digital circuits, as well as the time delay associated with the switching frequency, the closed loop will be unstable; moreover, raw ADC outputs have low signal-to-noise ratio, which usually need back-end calibration. In order to compensate these phase lag and make control loop unconditional stable, as well as boost up signal-to-noise ratio of the ADC block with cost-efficient design, a finite impulse response filter followed by digital proportional-integral-derivative blocks were designed. All these digital function blocks were optimised with processing speed. In the system simulation, it can be found that this controller achieved output regulation within 10% of nominal 5 V output voltage under 1 A/µs load transient condition; moreover, with the soft-start method, there is no turn-on overshooting. The die size of this controller is controlled within 3 mm2 by using 180 nm CMOS technology.

  14. Boosting foundations and algorithms

    CERN Document Server

    Schapire, Robert E

    2012-01-01

    Boosting is an approach to machine learning based on the idea of creating a highly accurate predictor by combining many weak and inaccurate "rules of thumb." A remarkably rich theory has evolved around boosting, with connections to a range of topics, including statistics, game theory, convex optimization, and information geometry. Boosting algorithms have also enjoyed practical success in such fields as biology, vision, and speech processing. At various times in its history, boosting has been perceived as mysterious, controversial, even paradoxical.

  15. How stem defects affect the capability of optimum bucking method?

    Directory of Open Access Journals (Sweden)

    Abdullah Emin Akay

    2015-07-01

    Full Text Available In forest harvesting activities, computer-assisted optimum bucking method increases the economic value of harvested trees. The bucking decision highly depends on the log quality grades which mainly vary with the surface characteristics such as stem defects and form of the stems. In this study, the effects of stem defects on optimum bucking method was investigated by comparing bucking applications which were conducted during the logging operations in two different Brutian Pine (Pinus brutia Ten stands. In the applications, the first stand contained the stems with relatively more stem defects than that of the stems in the second stand. The average number of defects per log for sample trees in the first and the second stand was recorded as 3.64 and 2.70, respectively. The results indicated that optimum bucking method increased the average economic value of harvested trees by 15.45% and 8.26 % in the stands, respectively. Therefore, the computer-assisted optimum bucking method potentially provides better results than that of traditional bucking method especially for the harvested trees with more stem defects.

  16. Nine Level Inverter with Boost Converter from Renewable Energy Source

    Directory of Open Access Journals (Sweden)

    Maruthu Pandiyan.R

    2015-01-01

    Full Text Available A new single phase nine level multilevel inverter is proposed. The input to the proposed nine level multilevel inverter is obtained from solar panel . The solar energy obtained from the solar panel is not constant and it varies with times. In order to maintain the constant voltage obtained from the solar panel the boost converter is used to maintain the constant output voltage using MPPT ( Perturb and observe algorithm algorithm. Then the buck boost converter output voltage is stored in the battery bank. Finally the battery energy is connected to the 9 level inverter circuits. The harmonics in the inverter is eliminated by using the fuzzy logic controller. The gate pulse for the multilevel inverter is given by the fuzzy logic controller which in turn reduces the harmonics in the inverter. Then the inverter output is connected to the grid are some application.

  17. Testicular Morphometry and Sperm Quality of Rabbit Bucks Fed ...

    African Journals Online (AJOL)

    Testicular Morphometry and Sperm Quality of Rabbit Bucks Fed Graded Levels ... for their nutritional and medicinal values and are rich in minerals and vitamins. ... used to evaluate the effect of Moringa oleifera leaf meal (MOLM) on testicular ...

  18. Instantaneous Current Feedback Control Strategy on Buck Mode Inverter

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Control strategies for Buck mode inverter have important effect on static and dynamic characteristics, reliability, load capacity, and short-circuit resistance. Instantaneous current feedback control strategies include instantaneous inductor current feedback control and instantaneous capacitor current feedback control, both of which have essential difference. When the Buck mode inverter respectively adopts instantaneous inductor current and capacitor current feedback control strategies, characteristics of stability, output voltage and power, short circuit, nonlinear load and dynamic are fully investigated in this paper.

  19. solar-based boost differen based boost differen ased boost ...

    African Journals Online (AJOL)

    eobe

    known as a Solar known as a Solar-based boost differential single ph ... vital to condition it to work at a particu its exponential .... problems of low and variable output voltage of PV and ..... was verified in the simulink within the Math lab 2007a.

  20. Learning Boost C++ libraries

    CERN Document Server

    Mukherjee, Arindam

    2015-01-01

    If you are a C++ programmer who has never used Boost libraries before, this book will get you up-to-speed with using them. Whether you are developing new C++ software or maintaining existing code written using Boost libraries, this hands-on introduction will help you decide on the right library and techniques to solve your practical programming problems.

  1. Field Plot Points for Buck Island Reef National Monument Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — This shapefile represents all the field plots visited on Buck Island. To fully comprehend this feature class, please refer to the full "Buck Island Reef National...

  2. LDA boost classification: boosting by topics

    Science.gov (United States)

    Lei, La; Qiao, Guo; Qimin, Cao; Qitao, Li

    2012-12-01

    AdaBoost is an efficacious classification algorithm especially in text categorization (TC) tasks. The methodology of setting up a classifier committee and voting on the documents for classification can achieve high categorization precision. However, traditional Vector Space Model can easily lead to the curse of dimensionality and feature sparsity problems; so it affects classification performance seriously. This article proposed a novel classification algorithm called LDABoost based on boosting ideology which uses Latent Dirichlet Allocation (LDA) to modeling the feature space. Instead of using words or phrase, LDABoost use latent topics as the features. In this way, the feature dimension is significantly reduced. Improved Naïve Bayes (NB) is designed as the weaker classifier which keeps the efficiency advantage of classic NB algorithm and has higher precision. Moreover, a two-stage iterative weighted method called Cute Integration in this article is proposed for improving the accuracy by integrating weak classifiers into strong classifier in a more rational way. Mutual Information is used as metrics of weights allocation. The voting information and the categorization decision made by basis classifiers are fully utilized for generating the strong classifier. Experimental results reveals LDABoost making categorization in a low-dimensional space, it has higher accuracy than traditional AdaBoost algorithms and many other classic classification algorithms. Moreover, its runtime consumption is lower than different versions of AdaBoost, TC algorithms based on support vector machine and Neural Networks.

  3. Heterologous Prime-Boost Vaccination

    OpenAIRE

    Lu, Shan

    2009-01-01

    An effective vaccine usually requires more than one time immunization in the form of prime-boost. Traditionally the same vaccines are given multiple times as homologous boosts. New findings suggested that prime-boost can be done with different types of vaccines containing the same antigens. In many cases such heterologous prime-boost can be more immunogenic than homologous prime-boost. Heterologous prime-boost represents a new way of immunization and will stimulate better understanding on the...

  4. Enhanced Buck-Boost Three-Level Neutral-Point-Clamped Inverters

    DEFF Research Database (Denmark)

    Tan, K. K.; Gao, F.; Chiang Loh, Poh

    2009-01-01

    In traditional three-level neutral-point-clamped (NPC) inverters, a major issue is capacitor voltage imbalance, which results in low order harmonics. The compensation of the capacitor voltages often require additional control complexity, which cannot be conveniently implemented. The "alternative ...

  5. Accurate Sliding-Mode Control System Modeling for Buck Converters

    DEFF Research Database (Denmark)

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

    2007-01-01

    This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively mod...... approach also predicts the self-oscillating switching action of the sliding-mode control system correctly. Analytical findings are verified by simulation as well as experimentally in a 10-30V/3A buck converter.......This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively...

  6. Solar Photovoltaic Powered Sailing Boat Using Buck Converter

    Directory of Open Access Journals (Sweden)

    Soumya Das

    2015-03-01

    Full Text Available The main objective of this paper is to establish technical and economical aspects of the application of stand-alone photovoltaic (PV system in sailing boat using a buck converter in order to enhance the power generation and also to minimize the cost. Performance and control of dc-dc converter, suitable for photovoltaic (PV applications, is presented here. A buck converter is employed here which extracts complete power from the PV source and feeds into the dc load. The power, which is fed into the load, is sufficient to drive a boat . With the help of matlab simulink software PV module and buck model has been designed and simulated and also compared with theoretical predictions.

  7. Accurate Modeling of Buck Converters with Magnetic-Core Inductors

    DEFF Research Database (Denmark)

    Astorino, Antonio; Antonini, Giulio; Swaminathan, Madhavan

    2015-01-01

    In this paper, a modeling approach for buck converters with magnetic-core inductors is presented. Due to the high nonlinearity of magnetic materials, the frequency domain analysis of such circuits is not suitable for an accurate description of their behaviour. Hence, in this work, a timedomain...... model of buck converters with magnetic-core inductors in a SimulinkR environment is proposed. As an example, the presented approach is used to simulate an eight-phase buck converter. The simulation results show that an unexpected system behaviour in terms of current ripple amplitude needs the inductor core...

  8. Relationships between physiological and behavioral responses of goat bucks in mating season

    Directory of Open Access Journals (Sweden)

    Serhat Karaca

    Full Text Available ABSTRACT The objective of this study was to determine the sexual parameters in young bucks with different sexual activity and the effect of experience (age on sexual parameters in bucks. Fifteen young, sexually inexperienced (SI and five adult, sexually experienced (SE Saanen × Hair goat crossbred bucks were used in this study. Bucks were individually exposed to three estrus does for 15-min periods during four sexual performance tests, which were carried out every other day to determine some sexual behavior traits such as flehmen response, reaction time, and ejaculation efficiency. Sexually inexperienced young bucks were evaluated based on their sexual activity (active (AC vs inactive (IA and presence of horn. It was found that AC bucks had significantly higher serum testosterone concentrations (31.5 vs 21.5 ng/mL and weight loss (114.2 vs 51.2 g/day than IA bucks. In addition, weight loss was significantly correlated with ejaculation efficiency in young bucks. On the other hand, horned bucks tended to have higher ejaculation efficiency with significantly longer reaction time than polled bucks. For experience (age classes, SE bucks had higher testosterone concentration (76.0 vs 31.5 ng/mL and weight loss (16.7 vs 8.6% than SI active young bucks. However, the effect of experience on other sexual performance traits was found to be limited. Overall, these results indicate that testosterone concentration may affect sexual performance of young bucks in the mating season. Age-related sexual experience is not a determining factor for sexual performance in bucks. However, sexual performance data alone may not reflect reproductive outcomes without semen data.

  9. Two phase interleaved buck converter for driving high power LEDs

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2011-01-01

    increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can...

  10. Power decoupling method for single phase differential buck converter

    DEFF Research Database (Denmark)

    Yao, Wenli; Tang, Yi; Zhang, Xiaobin

    2015-01-01

    The well-known inherent second-order ripple power in single phase converters imposes harmonic stress on the dc link, resulting in low efficiency and overheating issues. In order to avoid installing bulky electrolytic capacitors or LC filters in the dc-link, this paper presents a differential buck...

  11. Geologic Controls of Sand Boil Formation at Buck Chute, Mississippi

    Science.gov (United States)

    2017-06-30

    Geology ........................................................................................................................... 4 2.3 Description of...18 3.1 Geology of the Lower Mississippi River Valley...Hypothesis Sand boil formation at the Buck Chute site is the result of geology consisting of point bar and abandoned channel deposits with a thin

  12. "The Bell Curve" and Carrie Buck: Eugenics Revisited.

    Science.gov (United States)

    Smith, J. David

    1995-01-01

    The 1994 publication of "The Bell Curve" by R. Herrnstein and C. Murray is compared to other examples of eugenic principles, including the sterilization of "feebleminded" Carrie Buck, family degeneracy studies focusing on lower class Caucasian families, and other works that view the poorest and least educated members of society…

  13. Reproductive Parameters of the West African Dwarf Bucks Raised in ...

    African Journals Online (AJOL)

    DR Ezihe

    2Department of Animal Production, University of Agriculture, Makurdi ... Thirty West African Dwarf (WAD) bucks were evaluated for reproductive ... human consumption in the third world. ... animals. Testicular size and scrotal circumference are closely related to each other ... separately using a ''Diamond MCT 500'' model.

  14. A Simple Control Strategy Using Speedy Transient Response for Multiphase Buck Converter

    Science.gov (United States)

    Sasikala, K.; Ravikumar, D.; Rubini, B.

    2017-03-01

    The high performance of recent originating digital processors requires power supply for transient output, firm voltage regulation and high current. Industry has taken up interleaved multiphase synchronous buck converters for meeting such demands. Application of the voltage mode (ripple) hysteretic strategy to multiphase Voltage Regulator Units (VRU) would help satisfying many of the upcoming digital processors and IC’s powering demands. This arises from the use of the various advantages that can be obtained from this technique. This current division method is known for several benefits it provides: easy accessibility in application to all control methods, with freedom from the prime control technique in voltage regulation loop, absence of any necessity for current reference, better accuracy in current division of equal magnitude at almost every load conditions in standstill and transients. As against this, there are several challenges that involve distribution of multiple control signals, current sharing and sensitivity to noise, high speed comparators, hysteretic band accuracy and stable at large load transients. In addition, application of the current division technique presented was made to a multiphase voltage mode ripple controlled Buck Converter that produced a novel and easy control strategy having minimum output voltage ripples and speedy transient output.

  15. 一种软开关的交错并联Buck/Boost双向DC/DC变换器%A Type of Soft-Switching and Interleaving Bi-Directional DC/DC Converter

    Institute of Scientific and Technical Information of China (English)

    朱润卿; 刘军; 徐波

    2016-01-01

    针对传统硬开关双向直流变换器在高频工作时开关损耗较高的缺点,提出一种采用有源箝位软开关的多相交错并联Buck/Boost双向DC/DC变换器.这种变换器的开关管都能在零电压条件下开通,解决了开关管在开通时功率损耗较大的问题.借助SIMetrix软件工具,得出电路仿真结果,结果表明,变换器所有开关在Buck工作模式和Boost工作模式中均能实现软开关工作.%In view of the faults that traditional hard-switching bi-directional DC/DC converter working in high frequency caused much loss, a type of active clamped soft-switching of multiphase interleaving buck/boost bi-directional DC/DC converter is proposed, all switches of converter can be opened at zero voltage, it solves the problem of large loss of power switches.With the help of SIMetrix software tools, circuit simulation results are obtained.The simulation results show that the all switches of converter can achieve soft-switching in the buck mode and in the boost mode.

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

    Directory of Open Access Journals (Sweden)

    Kaoutar Elbakkar

    2011-11-01

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

  17. Closed Loop Control of Soft Switched Interleaved Buck Converter

    Directory of Open Access Journals (Sweden)

    R. Shenbagalakshmi

    2012-06-01

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

  18. Design & Implementation of Zero Voltage Switching Buck Converter

    Directory of Open Access Journals (Sweden)

    A.Suresh Kumar

    2014-09-01

    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.

  19. Decentralized Interleaving of Paralleled Dc-Dc Buck Converters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-01

    We present a decentralized control strategy that yields switch interleaving among parallel connected dc-dc buck converters without communication. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work represents the first fully decentralized strategy for switch interleaving of paralleled dc-dc buck converters.

  20. Fertility potential of rabbit bucks fed maize-based diets containing graded levels of fumonisin B1

    Directory of Open Access Journals (Sweden)

    Kingsley Idahor

    2012-07-01

    Full Text Available Fumonisin B1-contaminated maize-based diets have been reported to be mycotoxic in animal species, yet more validated data and biomarkers are needed. In this study, Fumonisin B1 (FB1 infected yellow-maize was used to formulate Diets 1, 2 and 3, containing 1,700, 1,800 and 1,900µg FB1/kg diet, respectively. Sixty sexually matured bucks and does were used, but only the bucks were fed the FB1-contaminated diets for eight weeks. At the end of the feeding trial, the treated bucks were mated to the dry does that were fed FB1-free yellow maize-based diet. Effects on testis and live weight, feed utilisation, conception rate, embryo development and spermatozoa production per gram testis were monitored. Results indicated significant depression (P<0.05 in feed intake, from 546.77±12.09g/week in Diet 1 with the lowest FB1 concentration, to 509.84±21.98g/week in Diet 3 with the highest FB1 concentration in the diets. Weight gain was drastically reduced (P<0.05 from 34.13±9.32g/week in Diet 1 to 20.38±22.13g/week in Diet 3. Meanwhile, some of the untreated does were pregnant in all the treatments, indicating that FB1 concentration at 2.0mg/kg diet may not be spermaticidal and there were no abnormalities in the embryos. It was observed that the paired testis weight value in Diet 1 (3.06±0.31 was not significantly different (P>0.05 from that of Diet 3 (2.94±0.23. The testicular elements were distorted by the dietary FB1, but did not follow a definite pattern. Spermatozoa production per gram testis values (31.1 – 37.3 x 106 recorded were much higher than 24 x 106 for a healthy rabbit buck. Consequently, FB1 concentration < 2.0mg/kg diet may not affect the fertility potentials of bucks orally dosed for a relatively short period. This observation further elucidates earlier discoveries that FB1 is not a reproductive toxicant. Hence, the United States Food and Drug Administration proposed a guideline of 2.0mg total fumonisins/kg diet, to be adopted with

  1. The AdaBoost Flow

    OpenAIRE

    Lykov, A.; Muzychka, S.; Vaninsky, K.

    2011-01-01

    We introduce a dynamical system which we call the AdaBoost flow. The flow is defined by a system of ODEs with control. We show that three algorithms of the AdaBoost family (i) the AdaBoost algorithm of Schapire and Freund (ii) the arc-gv algorithm of Breiman (iii) the confidence rated prediction of Schapire and Singer can be can be embedded in the AdaBoost flow. The nontrivial part of the AdaBoost flow equations coincides with the equations of dynamics of nonperiodic Toda system written in te...

  2. Design of a high efficiency 30 kW boost composite converter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeokjin [Univ. of Colorado, Boulder, CO (United States); Chen, Hua [Univ. of Colorado, Boulder, CO (United States); Maksimovic, Dragan [Univ. of Colorado, Boulder, CO (United States); Erickson, Robert W. [Univ. of Colorado, Boulder, CO (United States)

    2015-09-20

    An experimental 30 kW boost composite converter is described in this paper. The composite converter architecture, which consists of a buck module, a boost module, and a dual active bridge module that operates as a DC transformer (DCX), leads to substantial reductions in losses at partial power points, and to significant improvements in weighted efficiency in applications that require wide variations in power and conversion ratio. A comprehensive loss model is developed, accounting for semiconductor conduction and switching losses, capacitor losses, as well as dc and ac losses in magnetic components. Based on the developed loss model, the module and system designs are optimized to maximize efficiency at a 50% power point. Experimental results for the 30 kW prototype demonstrate 98.5%peak efficiency, very high efficiency over wide ranges of power and voltage conversion ratios, as well as excellent agreements between model predictions and measured efficiency curves.

  3. Enhanced Buck–Boost Neutral-Point-Clamped Inverters With Simple Capacitive-Voltage Balancing

    DEFF Research Database (Denmark)

    Tan, Kuan Khoon; Gao, Feng; Loh, Poh Chiang

    2010-01-01

    In traditional neutral-point-clamped (NPC) inverters, two major operating issues encountered are their relatively limited voltage-buck variation range and capacitive-voltage imbalance, which can cause low-order harmonics to appear at the inverter output. Various methodologies have so far been...... been investigated in the context of buck–boost energy conversion, even though relevant techniques for traditional NPC inverters do exist but are generally overburdened by the accompanied switching loss increase and more complex control and hardware circuitries. To address these two topological concerns...... simultaneously, two new buck–boost NPC inverters with simple capacitive-voltage-balancing capability are proposed. Both inverters are demonstrated to exhibit a doubling of voltage gain, with one of them also shown to produce a better output waveform quality. Simulation and experimental results are provided...

  4. Boosting Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Elkin Eduardo García Díaz

    2006-11-01

    Full Text Available En este artículo, se presenta un algoritmo de clasificación binaria basado en Support Vector Machines (Máquinas de Vectores de Soporte que combinado apropiadamente con técnicas de Boosting consigue un mejor desempeño en cuanto a tiempo de entrenamiento y conserva características similares de generalización con un modelo de igual complejidad pero de representación más compacta./ In this paper we present an algorithm of binary classification based on Support Vector Machines. It is combined with a modified Boosting algorithm. It run faster than the original SVM algorithm with a similar generalization error and equal complexity model but it has more compact representation.

  5. The AdaBoost Flow

    CERN Document Server

    Lykov, A; Vaninsky, K

    2011-01-01

    We introduce a dynamical system which we call the AdaBoost flow. The flow is defined by a system of ODEs with control. We show how by a suitable choice of control AdaBoost algorithm of Schapire and Freund and arc-gv algorithm of Breiman can be embedded in the AdaBoost flow. We also show how previously studied by Schapire and Singer confidence rated prediction can be obtained from our continuous time approach. We introduce a new continuous time algorithm which we call superBoost and describe its properties. The AdaBoost flow equations coincide with the equations of dynamics of the nonperiodic Toda system written in terms of spectral variables. This establishes a connection between two seemingly unrelated fields of boosting algorithms and classical integrable models. Finally we explain similarity of the AdaBoost flow with Perelman's ideas to control Ricci flow.

  6. Diversity-Based Boosting Algorithm

    Directory of Open Access Journals (Sweden)

    Jafar A. Alzubi

    2016-05-01

    Full Text Available Boosting is a well known and efficient technique for constructing a classifier ensemble. An ensemble is built incrementally by altering the distribution of training data set and forcing learners to focus on misclassification errors. In this paper, an improvement to Boosting algorithm called DivBoosting algorithm is proposed and studied. Experiments on several data sets are conducted on both Boosting and DivBoosting. The experimental results show that DivBoosting is a promising method for ensemble pruning. We believe that it has many advantages over traditional boosting method because its mechanism is not solely based on selecting the most accurate base classifiers but also based on selecting the most diverse set of classifiers.

  7. SUSY using boosted techniques

    CERN Document Server

    Stark, Giordon; The ATLAS collaboration

    2016-01-01

    In this talk, I present a discussion of techniques used in supersymmetry searches in papers published by the ATLAS Collaboration from late Run 1 to early Run 2. The goal is to highlight concepts the analyses have in common, why/how they work, and possible SUSY searches that could benefit from boosted studies. Theoretical background will be provided for reference to encourage participants to explore in depth on their own time.

  8. StructBoost: Boosting Methods for Predicting Structured Output Variables.

    Science.gov (United States)

    Chunhua Shen; Guosheng Lin; van den Hengel, Anton

    2014-10-01

    Boosting is a method for learning a single accurate predictor by linearly combining a set of less accurate weak learners. Recently, structured learning has found many applications in computer vision. Inspired by structured support vector machines (SSVM), here we propose a new boosting algorithm for structured output prediction, which we refer to as StructBoost. StructBoost supports nonlinear structured learning by combining a set of weak structured learners. As SSVM generalizes SVM, our StructBoost generalizes standard boosting approaches such as AdaBoost, or LPBoost to structured learning. The resulting optimization problem of StructBoost is more challenging than SSVM in the sense that it may involve exponentially many variables and constraints. In contrast, for SSVM one usually has an exponential number of constraints and a cutting-plane method is used. In order to efficiently solve StructBoost, we formulate an equivalent 1-slack formulation and solve it using a combination of cutting planes and column generation. We show the versatility and usefulness of StructBoost on a range of problems such as optimizing the tree loss for hierarchical multi-class classification, optimizing the Pascal overlap criterion for robust visual tracking and learning conditional random field parameters for image segmentation.

  9. 基于MATLAB的Buck/Boost直流变换器仿真%The Simulation of Buck/Boost DC-DC Converter Based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    韩学民

    2006-01-01

    对Buck和Boost直流变换器电路进行介绍,并且应用Matlab分别进行建模、仿真.在仿真过程中,改变触发脉冲的占空比,从而改变变换器的输出电压、电流,与理论分析结果进行比较.

  10. Digital DC-DC Converter Based on Buck-Boost Topology%基于Buck Boost拓扑的数字DC DC变换器设计

    Institute of Scientific and Technical Information of China (English)

    杜英; 郝茂森

    2014-01-01

    针对常规DC DC变换器输出电压调整困难、反馈实现复杂、智能化程度低的问题,提出了一种新型的能够根据用户要求快速改变输出电压的DC DC变换器,并且能够根据电源输入的电压变化情况实时调整控制参数,实现稳定的电压输出,且输出电压不受输入电压变化的影响。通过对不同负载和电源输入变化的实验验证,该DC DC变换器具有输出电压稳定精确、纹波率小、反馈快速准确的特点,对于某些对输入电压稳定性要求高的场合有实际应用意义。%Against the fact that the voltage values of DC-DC converter is difficult to adjust due to complex feedback and low degree of in-telligence,this paper proposes a new type of DC-DC converter that can be adjusted easily.This converter can adjust the control parame-ters along with the input voltage,keeping the output voltage stable.Experiments of different loads and input voltage show that this DC-DC converter has the advantage of stable output voltage,low voltage fluctuation,quick and accurate feedback.It has practical meaning in terms of requiring stable output voltage.

  11. Geologic map of the Alligator Ridge area, including the Buck Mountain East and Mooney Basin Summit quadrangles and parts of the Sunshine Well NE and Long Valley Slough quadrangles, White Pine County, Nevada

    Science.gov (United States)

    Nutt, Constance J.

    2000-01-01

    Data set describes the geology of Paleozoic through Quaternary units in the Alligator Ridge area, which hosts disseminated gold deposits. These digital files were used to create the 1:24,000-scale geologic map of the Buck Mountain East and Mooney Basin Summit Quadrangles and parts of the Sunshine Well NE and Long Valley Slough Quadrangles, White Pine County, east-central Nevada.

  12. 77 FR 12323 - Draft Environmental Impact Statement for the General Management Plan, Buck Island Reef National...

    Science.gov (United States)

    2012-02-29

    ... National Park Service Draft Environmental Impact Statement for the General Management Plan, Buck Island... Availability of a Draft Environmental Impact Statement for the General Management Plan (DEIS/GMP), Buck Island... alternatives for consideration, including a No-Action Alternative that continues current management policies...

  13. Biological Determinism and the Concept of Mental Retardation: The Lesson of Carrie Buck.

    Science.gov (United States)

    Smith, J. David

    This paper reviews the case of Carrie Buck, who was the first person sterilized (in 1927) under a Virginia law allowing sterilization of persons identified as incompetent and likely to genetically transmit physical, psychological, or social deficiencies to their offspring. This law was later upheld by the Supreme Court in Buck v. Bell, which…

  14. Exercise boosts immune response.

    Science.gov (United States)

    Sander, Ruth

    2012-06-29

    Ageing is associated with a decline in normal functioning of the immune system described as 'immunosenescence'. This contributes to poorer vaccine response and increased incidence of infection and malignancy seen in older people. Regular exercise can enhance vaccination response, increase T-cells and boost the function of the natural killer cells in the immune system. Exercise also lowers levels of the inflammatory cytokines that cause the 'inflamm-ageing' that is thought to play a role in conditions including cardiovascular disease; type 2 diabetes; Alzheimer's disease; osteoporosis and some cancers.

  15. A theory of multiclass boosting

    CERN Document Server

    Mukherjee, Indraneel

    2011-01-01

    Boosting combines weak classifiers to form highly accurate predictors. Although the case of binary classification is well understood, in the multiclass setting, the "correct" requirements on the weak classifier, or the notion of the most efficient boosting algorithms are missing. In this paper, we create a broad and general framework, within which we make precise and identify the optimal requirements on the weak-classifier, as well as design the most effective, in a certain sense, boosting algorithms that assume such requirements.

  16. Boost C++ application development cookbook

    CERN Document Server

    Polukhin, Antony

    2013-01-01

    This book follows a cookbook approach, with detailed and practical recipes that use Boost libraries.This book is great for developers new to Boost, and who are looking to improve their knowledge of Boost and see some undocumented details or tricks. It's assumed that you will have some experience in C++ already, as well being familiar with the basics of STL. A few chapters will require some previous knowledge of multithreading and networking. You are expected to have at least one good C++ compiler and compiled version of Boost (1.53.0 or later is recommended), which will be used during the exer

  17. Stability Aspects in One-Cycle Controlled Buck Converters

    Directory of Open Access Journals (Sweden)

    GURBINA, M.

    2014-02-01

    Full Text Available The paper aims to investigate issues related to one cycle controlled buck converters stability, in the situation when the integration capacitor discharging is performed through a non-zero value resistor, as it happens in practice. It is known that in this case the exponential discharge makes capacitor voltage theoretically never reach zero. Under these conditions, instability phenomena are expected when the discharge time is short, that is at high duty cycles. The stability condition is analytically derived with respect to the control voltage. It is shown that instability occurs with period doubling leading to a half switching frequency subharmonic. Computer simulations confirm the validity of theoretical considerations.

  18. Boosted beta regression.

    Directory of Open Access Journals (Sweden)

    Matthias Schmid

    Full Text Available Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1. Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures.

  19. Analytic boosted boson discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Larkoski, Andrew J.; Moult, Ian; Neill, Duff [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States)

    2016-05-20

    Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, D{sub 2}, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits. By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted Z boson from massive QCD background jets. We compare our results with Monte Carlo predictions which allows for a detailed understanding of the extent to which these generators accurately describe the formation of two-prong QCD jets, and informs their usage in substructure analyses. Our calculation also provides considerable insight into the discrimination power and calculability of jet substructure observables in general.

  20. Research on Single-phase Boot-Buck Power Factor Correction Converter Controlled With Dual Indispensable and Alternately-effect Current Loop%双电流环交替控制的单相升-降压功率因数校正变换器研究

    Institute of Scientific and Technical Information of China (English)

    毛鹏; 王川云; 徐明; 臧强

    2012-01-01

    Working principle of single-phase Boost-Buck power factor correction converter was analyzed, and the current control method of the converter in pure Boost and pure Buck mode was analyzed also. A new dual-mode control scheme constituting average current mode control and charge control was proposed. With this control scheme, input current of the converter can be well controlled not only in Boost mode, but also in Buck mode when the peak input voltage is larger than the output voltage, and high input power factor can be achieved meanwhile. Diagram of the dual-mode alternative control scheme was given, and the realizing method of charge control in digital control system was proposed. Validity of the theory analysis and the control scheme was verified through experimental results. Research results of this paper are referable for the control of single-phase cascaded Buck-Boost converter.%分析单相Boost-Buck功率因数校正变换器的工作原理,并对变换器在纯Boost和纯Buck模式下的电流控制问题进行分析.针对交流侧输入电压峰值大于输出电压的情况,提出由平均电流控制和电荷控制构成的双模式控制方案,确保变换器在一个基波周期内,不论在Boost,还是在Buck工作模式期间都可实现对输入电流的控制,达到功率因数校正的目的.文中给出双模式交替控制方案控制框图,并给出电荷控制方案的数字实现方法,最后通过实验对理论分析的正确性和控制方案的有效性进行验证.研究成果对于单相级联型Boost-Buck变换器的控制也有一定参考价值.

  1. Protective role of glutathione in buck semen cryopreservation.

    Science.gov (United States)

    Noei Razliqi, R; Zhandi, M; Shakeri, M; Towhidi, A; Sharafi, M; Emamverdi, M; Khodaei Motlagh, M

    2015-01-01

    The aim of this study was to determine the effect of low levels of glutathione on post-thawed buck sperm quality. In this experiment, different concentrations of glutathione [0 (LG-0), 0.5 (LG-0.5), 1 (LG-1), 1.5 (LG-1.5), and 2 (LG-2) mM] were added in a soybean lecithin-based extender. A total of 16 ejaculates from four bucks were collected and pooled. Each pooled sample was divided into five equal parts and each part was diluted by one of the above mentioned groups. After freeze-thawing process, motility and velocity, plasma membrane integrity and functionality, and apoptosis features of spermatozoa were evaluated. The results of this experiment showed that total motility (50.75 ± 2.33), plasma membrane integrity (55.75 ± 3.01) and functionality (46.75 ± 2.79) were higher in LG-1 extender compared to other extenders (Pbuck sperm quality compared to other extenders.

  2. Seasonal variations of cauda epididymal spermatozoa of bucks

    Directory of Open Access Journals (Sweden)

    Dilip Kumar Swain

    2016-09-01

    Full Text Available Objective: The study was conducted to evaluate the influence of season on cauda epididymal spermatozoa isolated from bucks. Materials and methods: Testes of 30 mature bucks were collected from local slaughter house, and were processed for the retrieval of cauda epididymal spermatozoa for evaluation. Testes were collected in three seasons (winter, summer and rainy, and each season was having 10 pairs of testicles. Recovered spermatozoa from the cauda epididymis were processed immediately for evaluation of semen attributes (Spermatozoa motility, viability, plasma membrane integrity, acrosomal status and DNA integrity. Results: Physiological effect of season was observed on progressive motility, percent of live spermatozoa, spermatozoal membrane integrity (HOST, acrosomal integrity, capacitation status and DNA integrity. Progressive motility, percent live spermatozoa, HOST positive spermatozoa, were found significantly (P<0.05 high in summer season, whereas, significantly (P<0.05 lower comet positive spermatozoa were found in summer season as compared to rainy and winter. Compromised acrosomal status was seen in winter and rainy seasons as compared to summer. Conclusion: Compromised acrosome along with plasma membrane and higher percentage of spermatozoa with damaged DNA in cauda spermatozoa were observed during winter and rainy seasons as compared to summer season. Summer season was found to be the most suitable season for collection of cauda epididymal spermatozoa and can effectively be used for assisted reproduction with further investigations of associated mechanisms. [J Adv Vet Anim Res 2016; 3(3.000: 263-267

  3. Boosted Higgs Shapes

    CERN Document Server

    Schlaffer, Matthias; Takeuchi, Michihisa; Weiler, Andreas; Wymant, Chris

    2014-01-01

    The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of $H\\to 2\\ell+\\mathbf{p}\\!\\!/_T$ via $H\\to \\tau\\tau$ and $H\\to WW^*$ could be performed and demonstrate that it offers a compelling alternative to the $t\\bar t H$ channel. We discuss the sensitivity to new physics in the most challenging scenario of an exactly SM-like inclusive Higgs cross-section.

  4. Boosted Higgs shapes

    Energy Technology Data Exchange (ETDEWEB)

    Schlaffer, Matthias [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Spannowsky, Michael [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Takeuchi, Michihisa [King' s College London (United Kingdom). Theoretical Physics and Cosmology Group; Weiler, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Wymant, Chris [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Laboratoire d' Annecy-le-Vieux de Physique Theorique, Annecy-le-Vieux (France)

    2014-05-15

    The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of H→2l+p{sub T} via H→ττ and H→WW{sup *} could be performed and demonstrate that it offers a compelling alternative to the t anti tH channel. We discuss the sensitivity to new physics in the most challenging scenario of an exactly SM-like inclusive Higgs cross-section.

  5. Boosted Higgs shapes

    Energy Technology Data Exchange (ETDEWEB)

    Schlaffer, Matthias [DESY, Hamburg (Germany); Spannowsky, Michael [Durham University, Department of Physics, Institute for Particle Physics Phenomenology, Durham (United Kingdom); Takeuchi, Michihisa [King' s College London, Theoretical Physics and Cosmology Group, Department of Physics, London (United Kingdom); Weiler, Andreas [DESY, Hamburg (Germany); CERN, Theory Division, Physics Department, Geneva 23 (Switzerland); Wymant, Chris [Durham University, Department of Physics, Institute for Particle Physics Phenomenology, Durham (United Kingdom); Laboratoire d' Annecy-le-Vieux de Physique Theorique, 9 Chemin de Bellevue, 74940, Annecy-le-Vieux (France); Imperial College London, Department of Infectious Disease Epidemiology, London (United Kingdom)

    2014-10-15

    The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of H → 2l + p{sub T} via H → ττ and H → WW* could be performed and demonstrate that it offers a compelling alternative to the t anti tH channel. We discuss the sensitivity to newphysics in the most challenging scenario of an exactly SM-like inclusive Higgs cross section. (orig.)

  6. Modelling and Simulation of Variable Frequency Synchronous DC-DC Buck Converter

    Directory of Open Access Journals (Sweden)

    Jeya Selvan Renius

    2014-10-01

    Full Text Available In this paper, novel small-signal averaged models for dc–dc converter operating at variable switching frequency are derived. This is achieved by separately considering the on-time and the off-time of the switching period. The derivation is shown in detail for a synchronous buck converter. The Enhanced Small Signal (ESSA Model is derived for the synchronous buck converter. The equivalent series inductance (ESL is also considered in this modelling. The buck converter model is also simulated in MATLAB and the result is also presented.

  7. The Model and Quadratic Stability Problem of Buck Converter in DCM

    Directory of Open Access Journals (Sweden)

    Li Xiaojing

    2016-01-01

    Full Text Available Quadratic stability is an important performance for control systems. At first, the model of Buck Converter in DCM is built based on the theories of hybrid systems and switched linear systems primarily. Then quadratic stability of SLS and hybrid feedback switching rule are introduced. The problem of Buck Converter’s quadratic stability is researched afterwards. In the end, the simulation analysis and verification are provided. Both experimental verification and theoretical analysis results indicate that the output of Buck Converter in DCM has an excellent performance via quadratic stability control and switching rules.

  8. Boosted ellipsoid ARTMAP

    Science.gov (United States)

    Anagnostopoulos, Georgios C.; Georgiopoulos, Michael; Verzi, Steven J.; Heileman, Gregory L.

    2002-03-01

    Ellipsoid ARTMAP (EAM) is an adaptive-resonance-theory neural network architecture that is capable of successfully performing classification tasks using incremental learning. EAM achieves its task by summarizing labeled input data via hyper-ellipsoidal structures (categories). A major property of EAM, when using off-line fast learning, is that it perfectly learns its training set after training has completed. Depending on the classification problems at hand, this fact implies that off-line EAM training may potentially suffer from over-fitting. For such problems we present an enhancement to the basic Ellipsoid ARTMAP architecture, namely Boosted Ellipsoid ARTMAP (bEAM), that is designed to simultaneously improve the generalization properties and reduce the number of created categories for EAM's off-line fast learning. This is being accomplished by forcing EAM to be tolerant about occasional misclassification errors during fast learning. An additional advantage provided by bEAM's desing is the capability of learning inconsistent cases, that is, learning identical patterns with contradicting class labels. After we present the theory behind bEAM's enhancements, we provide some preliminary experimental results, which compare the new variant to the original EAM network, Probabilistic EAM and three different variants of the Restricted Coulomb Energy neural network on the square-in-a-square classification problem.

  9. High Resolution Imagery of Buck Island Coral Reef Systems Prior to and During Suspected Bleaching Events

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a collection of imagery of Buck Island coral reef systems. They are pairs of imagery where one image was acquired during a suspected bleaching event....

  10. Rich, Well-Educated Get Bigger Bang for Buck from Mediterranean Diet

    Science.gov (United States)

    ... Well-Educated Get Bigger Bang for Buck From Mediterranean Diet Researchers suspect food quality may account for ... 2017 TUESDAY, Aug. 1, 2017 (HealthDay News) -- The Mediterranean diet -- rich in fruits, vegetables, fish, olive oil, ...

  11. Backscatter 0.5m TIFF Mosaic of St. Croix (Buck Island), US Virgin Islands, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 0.5 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands. NOAA's NOS/NCCOS/CCMA Biogeography...

  12. Distribution-Specific Agnostic Boosting

    CERN Document Server

    Feldman, Vitaly

    2009-01-01

    We consider the problem of boosting the accuracy of weak learning algorithms in the agnostic learning framework of Haussler (1992) and Kearns et al. (1992). Known algorithms for this problem (Ben-David et al., 2001; Gavinsky, 2002; Kalai et al., 2008) follow the same strategy as boosting algorithms in the PAC model: the weak learner is executed on the same target function but over different distributions on the domain. We demonstrate boosting algorithms for the agnostic learning framework that only modify the distribution on the labels of the points (or, equivalently, modify the target function). This allows boosting a distribution-specific weak agnostic learner to a strong agnostic learner with respect to the same distribution. When applied to the weak agnostic parity learning algorithm of Goldreich and Levin (1989) our algorithm yields a simple PAC learning algorithm for DNF and an agnostic learning algorithm for decision trees over the uniform distribution using membership queries. These results substantia...

  13. Yoga May Boost Aging Brains

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_167693.html Yoga May Boost Aging Brains Changes seen in areas ... and memory, but it's not yet clear if yoga is the cause To use the sharing features ...

  14. Reliability-Oriented Design of LC Filter in Buck DC-DC Converter

    DEFF Research Database (Denmark)

    Liu, Yi; Huang, Meng; Wang, Huai;

    2015-01-01

    State-of-the-art LC filter design of buck DC-DC converter is based on the specifications of voltage and current ripples and constrains in power density and cost. Since lifetime is an important performance factor in reliability critical applications, this digest proposes a method to optimize...... an optimized LC filter design to fulfill the required lifetime. The theoretical analysis and simulation study are presented which are verified by the experimental results from a buck converter prototype....

  15. Acoustical Evaluation of Bucking Bars during Riveting Operations in Bldg 9001, Tinker AFB, Oklahoma

    Science.gov (United States)

    2013-11-14

    bar can be either a formed piece of metal used alone, see Figure 1, or the dolly portion of a dampened bucking bar, see Figure 2. c. Sample...bucking bars, 135 total rivets for each of the three processes. Dolly 4 Distribution A: Approved for public release; distribution is...Industrial Tool TP111R (handle) TP1510A ( dolly ) 4. RESULTS: Assessment data for all three processes are displayed in Figures 3, 4, and 5

  16. Buck Converter with Soft-Switching Cells for PV Panel Applications

    Directory of Open Access Journals (Sweden)

    Cheng-Tao Tsai

    2016-03-01

    Full Text Available In power conversion of photovoltaic (PV energy, a hard-switching buck converter always generates some disadvantages. For example, serious electromagnetic interference (EMI, high switching losses, and stresses on an active switch (metal-oxide-semiconductor-field-effect-transistor, MOSFET, and high reverse-recovery losses of a freewheeling diode result in low conversion efficiency. To release these disadvantages, a buck converter with soft-switching cells for PV panel applications is proposed. To create zero-voltage-switching (ZVS features of the active switches, a simple active soft-switching cell with an inductor, a capacitor, and a MOSFET is incorporated into the proposed buck converter. Therefore, the switching losses and stresses of the active switches and EMI can be reduced significantly. To reduce reverse-recovery losses of a freewheeling diode, a simple passive soft-switching cell with a capacitor and two diodes is implemented. To verify the performance and the feasibility of the proposed buck converter with soft-switching cells for PV panel applications, a prototype soft-switching buck converter is built and implemented by using a maximum-power-point-tracking (MPPT method. Simulated and experimental results are presented from a 100 W soft-switching buck converter for PV panel applications.

  17. Modeling and Characteristics Analysis for a Buck-Boost Converter in Pseudo-Continuous Conduction Mode Based on Fractional Calculus

    OpenAIRE

    2016-01-01

    In recent days, fractional calculus (FC) has been accepted as a novel modeling tool that can extend the descriptive power of the traditional calculus. Fractional-order descriptiveness can increase the flexibility and degrees of freedom of the model by means of fractional parameters. Based on the fact that real capacitors and inductors are “intrinsic” fractional order, fractional calculus is introduced into the modeling process to establish a fractional-order state-space averaging model of the...

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

    DEFF Research Database (Denmark)

    Dimopoulos, Emmanouil; Munk-Nielsen, Stig

    2014-01-01

    Interest on Dielectric ElectroActive Polymer (DEAP) generators has aroused among scientists in recent years, due to the former ones' documented advantages against competing electromagnetic and field-activated technologies. Yet, the need for bidirectional energy flow under high step-up and high st...

  19. Novel Family of Single-Phase Modified Impedance-Source Buck-Boost Multilevel Inverters with Reduced Switch Count

    DEFF Research Database (Denmark)

    Husev, Oleksandr; Strzelecki, Ryszard; Blaabjerg, Frede

    2016-01-01

    This paper describes novel single-phase solutions with increased inverter voltage levels derived by means of a nonstandard inverter configuration and impedance source networks. Operation principles based on special modulation techniques are presented. Detailed component design guidelines along wi...... with simulation and experimental verification are also provided. Possible application fields are discussed, as well as advantages and disadvantages. Finally, future studies are addressed for the new solutions....

  20. Control of second-life hybrid battery energy storage system based on modular boost-multilevel buck converter

    OpenAIRE

    Mukherjee, Nilanjan; Strickland, Dani

    2015-01-01

    To fully utilize second-life batteries on the grid system, a hybrid battery scheme needs to be considered for several reasons: the uncertainty over using a single source supply chain for second-life batteries, the differences in evolving battery chemistry and battery configuration by different suppliers to strive for greater power levels, and the uncertainty of degradation within a second-life battery. Therefore, these hybrid battery systems could have widely different module voltage, capacit...

  1. Basic MOSFET Based vs Couple-coils Boost Converters for Photovoltaic Generators

    Directory of Open Access Journals (Sweden)

    Pierre Petit

    2014-02-01

    Full Text Available Considering the optimization of a photovoltaic system, several studies show the advantage in the choice of a distributed structure. For such structures small power converters such as the boosts and buck converters appear as most appropriate. We have analysed the efficiency of small power boost-converters especially dedicated for photovoltaic energy conversion systems working in the middle and high voltage ranges. The setup studied is a photovoltaic generator connected to an AC grid working in 230 Volts via an inverter. More over, we considered the possibility of multiple electrical energy sources as photovoltaic, wind systems in the same energy production system, which obliged an adaptive converter structure. We evaluated the losses in the various stages of a boost converter and point out the importance of the power MOSFET used as the commutation element. New transistors databases obtained from manufacturers show the nonlinear dependency between the resistance drain-source when passing, Rdson and the maximum rating voltage when the transistor is off, Vdsmax, for all transistor families. Thus nonlinear dependency induces a huge increase of losses with the voltage in the MOSFET, and as a direct consequence in the converter the more as Vdsmax is higher. In order to minimize losses of the converter we have designed and realized a new high efficiency version of a Step-Up structure based on a commutation element integrating a low Vdsmax voltage MOSFET and very low Rdson.

  2. FPA Tuned Fuzzy Logic Controlled Synchronous Buck Converter for a Wave/SC Energy System

    Directory of Open Access Journals (Sweden)

    SAHIN, E.

    2017-02-01

    Full Text Available This paper presents a flower pollination algorithm (FPA tuned fuzzy logic controlled (FLC synchronous buck converter (SBC for an integrated wave/ supercapacitor (SC hybrid energy system. In order to compensate the irregular wave effects on electrical side of the wave energy converter (WEC, a SC unit charged by solar panels is connected in parallel to the WEC system and a SBC is controlled to provide more reliable and stable voltage to the DC load. In order to test the performance of the designed FLC, a classical proportional-integral-derivative (PID controller is also employed. Both of the controllers are optimized by FPA which is a pretty new optimization algorithm and a well-known optimization algorithm of which particle swarm optimization (PSO to minimize the integral of time weighted absolute error (ITAE performance index. Also, the other error-based objective functions are considered. The entire energy system and controllers are developed in Matlab/Simulink and realized experimentally. Real time applications are done through DS1104 Controller Board. The simulation and experimental results show that FPA tuned fuzzy logic controller provides lower value performance indices than conventional PID controller by reducing output voltage sags and swells of the wave/SC energy system.

  3. Modeling and Control of Primary Parallel Isolated Boost Converter

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Hernandez Botella, Juan Carlos; Sen, Gökhan

    2012-01-01

    In this paper state space modeling and closed loop controlled operation have been presented for primary parallel isolated boost converter (PPIBC) topology as a battery charging unit. Parasitic resistances have been included to have an accurate dynamic model. The accuracy of the model has been tes...

  4. Resolving boosted jets with XCone

    Energy Technology Data Exchange (ETDEWEB)

    Thaler, Jesse; Wilkason, Thomas F. [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA, 02139 (United States)

    2015-12-09

    We show how the recently proposed XCone jet algorithm http://dx.doi.org/10.1007/JHEP11(2015)072 smoothly interpolates between resolved and boosted kinematics. When using standard jet algorithms to reconstruct the decays of hadronic resonances like top quarks and Higgs bosons, one typically needs separate analysis strategies to handle the resolved regime of well-separated jets and the boosted regime of fat jets with substructure. XCone, by contrast, is an exclusive cone jet algorithm that always returns a fixed number of jets, so jet regions remain resolved even when (sub)jets are overlapping in the boosted regime. In this paper, we perform three LHC case studies — dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs — that demonstrate the physics applications of XCone over a wide kinematic range.

  5. Resolving boosted jets with XCone

    Science.gov (United States)

    Thaler, Jesse; Wilkason, Thomas F.

    2015-12-01

    We show how the recently proposed XCone jet algorithm [1] smoothly interpolates between resolved and boosted kinematics. When using standard jet algorithms to reconstruct the decays of hadronic resonances like top quarks and Higgs bosons, one typically needs separate analysis strategies to handle the resolved regime of well-separated jets and the boosted regime of fat jets with substructure. XCone, by contrast, is an exclusive cone jet algorithm that always returns a fixed number of jets, so jet regions remain resolved even when (sub)jets are overlapping in the boosted regime. In this paper, we perform three LHC case studies — dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs — that demonstrate the physics applications of XCone over a wide kinematic range.

  6. Resolving Boosted Jets with XCone

    CERN Document Server

    Thaler, Jesse

    2015-01-01

    We show how the recently proposed XCone jet algorithm smoothly interpolates between resolved and boosted kinematics. When using standard jet algorithms to reconstruct the decays of hadronic resonances like top quarks and Higgs bosons, one typically needs separate analysis strategies to handle the resolved regime of well-separated jets and the boosted regime of fat jets with substructure. XCone, by contrast, is an exclusive cone jet algorithm that always returns a fixed number of jets, so jet regions remain resolved even when (sub)jets are overlapping in the boosted regime. In this paper, we perform three LHC case studies---dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs---that demonstrate the physics applications of XCone over a wide kinematic range.

  7. Boost.Asio C++ network programming

    CERN Document Server

    Torjo, John

    2013-01-01

    What you want is an easy level of abstraction, which is just what this book provides in conjunction with Boost.Asio. Switching to Boost.Asio is just a few extra #include directives away, with the help of this practical and engaging guide.This book is great for developers that need to do network programming, who don't want to delve into the complicated issues of a raw networking API. You should be familiar with core Boost concepts, such as smart pointers and shared_from_this, resource classes (noncopyable), functors and boost::bind, boost mutexes, and the boost date/time library. Readers should

  8. Boosted Horizon of a Boosted Space-Time Geometry

    CERN Document Server

    Battista, Emmanuele; Scudellaro, Paolo; Tramontano, Francesco

    2015-01-01

    We apply the ultrarelativistic boosting procedure to map the metric of Schwarzschild-de Sitter spacetime into a metric describing de Sitter spacetime plus a shock-wave singularity located on a null hypersurface, by exploiting the picture of the embedding of an hyperboloid in a five-dimensional Minkowski spacetime. After reverting to the usual four-dimensional formalism, we also solve the geodesic equation and evaluate the Riemann curvature tensor of the boosted Schwarzschild-de Sitter metric by means of numerical calculations, which make it possible to reach the ultrarelativistic regime gradually by letting the boost velocity approach the speed of light. Eventually, the analysis of the Kretschmann invariant (and of the geodesic equation) shows the global structure of space- time, as we demonstrate the presence of a "scalar curvature singularity" within a 3-sphere and find that it is also possible to define what we have called "boosted horizon", a sort of elastic wall where all particles are surprisingly pushe...

  9. Thoracic aortic aneurysm in a buck associated with caseous lymphadenitis

    Directory of Open Access Journals (Sweden)

    R.R. Pinheiro

    2013-06-01

    Full Text Available This paper reports the clinical, bacteriological and pathological findings of a thoracic aortic aneurysm in a four-year-old Anglo-Nubian goat buck, related to a framework of visceral caseous lymphadenitis. General clinical examination showed heart rate of 75 beats per minute, respiratory rate of 20 movements per minute and ruminal movements of four movements per minute. Superficial lymph nodes were normal upon palpation. Rectal temperature was slightly high (40.5°C. Blood test showed an intense leukocytosis (54,000/µL, characterized by strong neutrophil shift to the left. At necropsy, a large blood clot was detected in the thoracic cavity. The thickening of the myocardium and dilatation of the aorta in the thoracic portion, presenting a saculiform format was also observed. A large number of abscesses were disseminated in the media and intima layers of aorta. The aorta lumen obstruction by arterial plaques consisting of inflammatory infiltrate, predominantly neutrophilic was also detected. Abscesses were found spread in turbinate, rumen, reticulum, kidneys, liver, spleen, testicles and aorta wall. The microbiological exam of exudate confirmed Corynebacterium pseudotuberculosis as the causal agent.

  10. 50 MHz dual-mode buck DC—DC converter

    Science.gov (United States)

    Zhang, Zhang; Xing, Wang; Wencheng, Yu; Ye, Tan; Yizhong, Yang; Guangjun, Xie

    2016-08-01

    A 50 MHz 1.8/0.9 V dual-mode buck DC—DC converter is proposed in this paper. A dual-mode control for high-frequency DC—DC converter is presented to enhance the conversion efficiency of light-load in this paper. A novel zero-crossing detector is proposed to shut down synchronous rectification transistor NMOS when the inductor crosses zero, which can decrease the power loss caused by reverse current and the trip point is adjusted by regulating IBIAS (BIAS current). A new logic control for pulse-skipping modulation loop is also presented in this paper, which has advantages of simple structure and low power loss. The proposed converter is realized in SMIC 0.18 μm 1-poly 6-metal mixed signal CMOS process. With switching loss, conduction loss and reverse current related loss optimized, an efficiency of 57% is maintained at 10 mA, and a peak efficiency of 71% is measured at nominal operating conditions with a voltage conversion of 1.8 to 0.9 V. Project supported by the National Natural Science Foundation of China (Nos. 61404043, 61401137), the Key Laboratory of Infrared Imaging Material and Detectors, Shanghai Institute of Technical Physics, CAS (Nos. IIMDKFJJ-13-06, IIMDKFJJ-14-03), and the Fundamental Research Funds for the Central University (No. 2015HGZX0026).

  11. How One Clinic Got a Big Boost in HPV Vaccination Rates

    Science.gov (United States)

    ... One Clinic Got a Big Boost in HPV Vaccination Rates The cervical cancer vaccine was treated as ... the United States, lagging far behind other recommended vaccinations in this age group. But, by lumping HPV ...

  12. BIM-Boost in Nederland

    NARCIS (Netherlands)

    Berlo, L.A.H.M.

    2012-01-01

    Onlangs sloot TNO een samenwerkingsovereenkomst met brancheorganisaties in de bouwkolom waaromder Bouwend Nederland en BNA. Doel van de overeenkomst: een BIM-boost in Nederland bewerkstelligen. Een gesprek met Leon van Berlo van TNO over deze en andere BIM-actualiteiten

  13. BIM-Boost in Nederland

    NARCIS (Netherlands)

    Berlo, L.A.H.M.

    2012-01-01

    Onlangs sloot TNO een samenwerkingsovereenkomst met brancheorganisaties in de bouwkolom waaromder Bouwend Nederland en BNA. Doel van de overeenkomst: een BIM-boost in Nederland bewerkstelligen. Een gesprek met Leon van Berlo van TNO over deze en andere BIM-actualiteiten

  14. Representing Arbitrary Boosts for Undergraduates.

    Science.gov (United States)

    Frahm, Charles P.

    1979-01-01

    Presented is a derivation for the matrix representation of an arbitrary boost, a Lorentz transformation without rotation, suitable for undergraduate students with modest backgrounds in mathematics and relativity. The derivation uses standard vector and matrix techniques along with the well-known form for a special Lorentz transformation. (BT)

  15. Detection of Illegitimate Emails using Boosting Algorithm

    DEFF Research Database (Denmark)

    Nizamani, Sarwat; Memon, Nasrullah; Wiil, Uffe Kock

    2011-01-01

    In this paper, we report on experiments to detect illegitimate emails using boosting algorithm. We call an email illegitimate if it is not useful for the receiver or for the society. We have divided the problem into two major areas of illegitimate email detection: suspicious email detection...... and spam email detection. For our desired task, we have applied a boosting technique. With the use of boosting we can achieve high accuracy of traditional classification algorithms. When using boosting one has to choose a suitable weak learner as well as the number of boosting iterations. In this paper, we...... propose suitable weak learners and parameter settings for the boosting algorithm for the desired task. We have initially analyzed the problem using base learners. Then we have applied boosting algorithm with suitable weak learners and parameter settings such as the number of boosting iterations. We...

  16. Research on Two-channel Interleaved Two-stage Paralleled Buck DC-DC Converter for Plasma Cutting Power Supply

    DEFF Research Database (Denmark)

    Yang, Xi-jun; Qu, Hao; Yao, Chen

    2014-01-01

    As for high power plasma power supply, due to high efficiency and flexibility, multi-channel interleaved multi-stage paralleled Buck DC-DC Converter becomes the first choice. In the paper, two-channel interleaved two- stage paralleled Buck DC-DC Converter powered by three-phase AC power supply...

  17. 75 FR 22168 - ADSOUTH PARTNERS, Inc., American Racing Capital, Inc., Buck-A-Roo$ Holding Corporation, DDS...

    Science.gov (United States)

    2010-04-27

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION ADSOUTH PARTNERS, Inc., American Racing Capital, Inc., Buck-A- Roo$ Holding Corporation, DDS... there is a lack of current and accurate information concerning the securities of Buck-A-Roo$ Holding...

  18. Semen characteristics and sperm morphological studies of the West African Dwarf Buck treated with Aloe vera gel extract

    Directory of Open Access Journals (Sweden)

    Oyeyemi Matthew Olugbenga

    2011-01-01

    Full Text Available Background: Aloe vera (Aloe barbadensis miller is an evergreen perennial plant widely used in modern herbal practice and is often available in proprietary herbal preparations.Objective: This study was designed to investigate the semen picture and spermatozoa morphology of West African Dwarf (WAD bucks treated with Aloe vera extract.Materials and Methods: Twelve sexually matured WAD bucks, weighing between 11 and 15 kg, were used for the study. The bucks were first used as control (pre-treatment and later as two groups of six animals each. The first six bucks received 10 mls of the 3% extract while the other six received 10 mls of the 4% of the extract for a 7 day period. Semen was collected from both the 3 and 4% extract treated bucks for the control (pre-treatment, on days eight (first week post-treatment and fifteen (second week post-treatment in each case using the electroejaculation method. The spermiogram of the bucks were investigated using standard procedures. Data obtained were analyzed using two way ANOVA and significance reported at p<0.05.Results: The continuous administration of Aloe vera extract significantly (p<0.05 reduced sperm concentration, motility and percentage livability and resulted in increased sperm abnormalities in the WAD buck.Conclusion: Aloe vera adversely affected the spermiogram of bucks. The plant can reduce fertility in male animals and is therefore not recommended for medicinal purpose in male animals especially those used for breeding.

  19. Nonlinear Phenomena and Resonant Parametric Perturbation Control in QR-ZCS Buck DC-DC Converters

    Science.gov (United States)

    Hsieh, Fei-Hu; Liu, Feng-Shao; Hsieh, Hui-Chang

    The purpose of this study is to investigate the chaotic phenomena and to control in current-mode controlled quasi-resonant zero-current-switching (QR-ZCS) DC-DC buck converters, and to present control of chaos by resonant parametric perturbation control methods. First of all, MATLAB/SIMULINK is used to derive a mathematical model for QR-ZCS DC-DC buck converters, and to simulate the converters to observe the waveform of output voltages, inductance currents and phase-plane portraits from the period-doubling bifurcation to chaos by changing the load resistances. Secondly, using resonant parametric perturbation control in QR-ZCS buck DC-DC converters, the simulation results of the chaotic converter form chaos state turn into stable state period 1, and improve ripple amplitudes of converters under the chaos, to verify the validity of the proposes method.

  20. On the Disillusionment of American Dream Through Buck in The Call of the Wild

    Institute of Scientific and Technical Information of China (English)

    吕颖

    2015-01-01

    The Call of the Wild,written by the famous American novelist Jack London,has attracted a large number of both readers and scholars ever since it came out.It provides the public with a fresh perspective through narrating the whole novel from the point of view of the protagonist Buck,a dog.Against the background of countless people flooding into the Alaska to search gold in order to fulfill their dream of becoming rich,which,to some extent,represents the American dream at that time,this novel vividly mirrored the then phenomenon,so illuminating and thought-provoking that it is of great value to analyze the disillusionment of American Dream through Buck.Therefore,this paper aims at exploring the disillusionment of American Dream through analyzing Buck and his rich life experiences.

  1. Energy iteration model research of DCM Buck converter with multilevel pulse train technique

    Science.gov (United States)

    Qin, Ming; Li, Xiang

    2017-08-01

    According as the essence of switching converter is the nature of energy, the energy iteration model of the Multilevel Pulse Train (MPT) technique is studied in this paper. The energy iteration model of DCM Buck converter with MPT technique can reflect the control law and excellent transient performance of the MPT technique. The iteration relation of energy transfer in switching converter is discussed. The structure and operation principle of DCM Buck converter with MPT technique is introduced and the energy iteration model of this converter is set up. The energy tracks of MPT-control Buck converter and PT converter is researched and compared to show that the ratio of steady-state control pulse satisfies the expectation for the MPT technique and the MPT-controlled switching converter has much lower output voltage ripple than the PT converter.

  2. Analysis of Discharge Spark Energy in Buck Converter of a Continuous Mode of Inductive Current

    Institute of Scientific and Technical Information of China (English)

    CUI Bao-chun; CHENG Hong; WANG Cong; LU Huan-yu; SHI Yun

    2006-01-01

    The basic idea of intrinsically safe circuit and the discharge spark in the Buck converter in the explosive atmospheres were introduced. The Buck converter is the main topological structure of the switch type of intrinsically safe circuit, which has two working modes: continuous inductive current (CCM - continuous conduction mode) and discrete inductance current (DCM - discontinuous conduction mode). The operating state of the continuous inductive current mode is analyzed in detail and the energy of discharge spark in various operating modes is discussed. The total energy will decrease with the increase of switch frequency, in a switching cycle; the discharge spark energy has a maximum and a minimum value. Therefore, the Buck converter has smaller discharge spark energy than the linear power circuit and the switch type of intrinsically safe circuit can enhance the output power and the conversion efficiency of the intrinsically safe power.

  3. Application of Theory of Hybrid Systems to Control the Switching of Buck Converter

    KAUST Repository

    Benmiloud, Mohammed

    2013-08-01

    The field of power electronics poses challenging control problems that can’t be treated in a complete manner using traditional modeling. In this paper, the buck converter operating in Continuous Conduction Mode (CCM) is represented analytically by hybrid automaton model and graphically representation is also given. The hybrid trajectory and the model behavior are presented. The control problem of buck switching converters is transformed to a guard selection problem. The guard selection calculation formulas of buck converter are derived from the basic circuit laws. The stability of the switching is established analytically by the use of multiple Lyapunov functions to ensure the convergence and Poincare map to assess the local stability of the limit cycle. Numerical results clearly bring out the advantages and effectiveness of the proposed control law under varying line voltage and load conditions. Simulation studies are carried out in Matlab/Simulink/Stateflow.

  4. Finite-time control of DC-DC buck converters via integral terminal sliding modes

    Science.gov (United States)

    Chiu, Chian-Song; Shen, Chih-Teng

    2012-05-01

    This article presents novel terminal sliding modes for finite-time output tracking control of DC-DC buck converters. Instead of using traditional singular terminal sliding mode, two integral terminal sliding modes are introduced for robust output voltage tracking of uncertain buck converters. Different from traditional sliding mode control (SMC), the proposed controller assures finite convergence time for the tracking error and integral tracking error. Furthermore, the singular problem in traditional terminal SMC is removed from this article. When considering worse modelling, adaptive integral terminal SMC is derived to guarantee finite-time convergence under more relaxed stability conditions. In addition, several experiments show better start-up performance and robustness.

  5. Bifurcation and Chaos in a Pulse Width modulation controlled Buck Converter

    DEFF Research Database (Denmark)

    Kocewiak, Lukasz; Bak, Claus Leth; Munk-Nielsen, Stig

    2007-01-01

    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....

  6. A unified active damping control for single-phase differential buck inverter with LCL-filter

    DEFF Research Database (Denmark)

    Yao, Wenli; Wang, Xiongfei; Zhang, Xiaobin

    2015-01-01

    The single-phase differential mode buck inverter is recently introduced with a differential mode for power transfer and a common mode for actively decoupling the second-order power oscillation. However, it is limited to islanded applications with an LC filter. This paper addresses the stability...... and control of a grid-connected differential mode buck inverter with an LCL filter. A generalized small-signal model of the inverter is built first with the averaged switching model. It is shown that the LCL filter resonance merely occurs in the differential mode, while an LC filter resonance exists...

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

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Maheshwari, Ram Krishan; Nielsen, Rasmus Ørndrup

    2012-01-01

    Half-bridge inverters, full-bridge inverters and bidirectional buck converters share a common topological structure, in which two switches and two diodes are present. In such a topology, a dead time between the two signals controlling the switches is inserted. This influences the relationship...... proposed. However, the measurement of the current is normally required for all dead-time compensation strategies, which can be a problem when the current approaches or crosses zero. In this paper, the operation of a bidirectional buck converter in the region around zero current has been analytically...

  8. 基于改善关联性 Buck 变换器的混沌控制*%Chaotic control of the Buck converter based on improving the correlation∗

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      由于 Buck 变换器具有非线性特性,在一定参数条件下,它会处于混沌状态,此时 Buck 变换器不能正常工作。为了抑制 Buck 变换器的混沌现象,本文首先建立了 Buck 变换器的精确状态方程模型,然后通过分析可控范围图、开关逻辑图、相图、电感电流波形、输出电压波形,研究了基于改善 Buck 变换器的电感电流与输出电压之间关联性的混沌控制策略。研究结果表明:该控制策略能够将处于混沌状态的 Buck 变换器稳定在周期1,2,4,8轨道,且该控制策略不需要预先确定期望的目标轨道,不依赖于 Buck 变换器的电路参数,只取决于一个外部参数即耦合强度,所以该控制策略同样适用于其他拓扑结构的功率变换器。%Due to the strong nonlinearity of the Buck converter, it can be in the chaotic state under certain parameters and the chaotic Buck converter does not work normally. In order to suppress the chaotic phenomena in the Buck converter, a chaotic control scheme is demonstrated by establishing the accurate state equation models, and then analyzing the controllable range diagrams, the switching logic diagrams, the phase portrait, the inductor current waveforms and the output voltage waveforms. Also this scheme can be im-plemented by improving the correlation between the inductor current and the output voltage of the Buck converter. Research results show that this scheme can stabilize the chaotic Buck converter to the period-1, period-2, period-4, period-8 orbits, without determining the desired targeting orbits in advance. Moreover, this scheme does not depend on circuit parameters of the Buck converter, it only depends on an external parameter named the coupling strength, so this scheme can be applied to the other power converters.

  9. ada: An R Package for Stochastic Boosting

    Directory of Open Access Journals (Sweden)

    Mark Culp

    2006-09-01

    Full Text Available Boosting is an iterative algorithm that combines simple classification rules with ‘mediocre’ performance in terms of misclassification error rate to produce a highly accurate classification rule. Stochastic gradient boosting provides an enhancement which incorporates a random mechanism at each boosting step showing an improvement in performance and speed in generating the ensemble. ada is an R package that implements three popular variants of boosting, together with a version of stochastic gradient boosting. In addition, useful plots for data analytic purposes are provided along with an extension to the multi-class case. The algorithms are illustrated with synthetic and real data sets.

  10. ada: An R Package for Stochastic Boosting

    Directory of Open Access Journals (Sweden)

    Mark Culp

    2006-09-01

    Full Text Available Boosting is an iterative algorithm that combines simple classification rules with "mediocre" performance in terms of misclassification error rate to produce a highly accurate classification rule. Stochastic gradient boosting provides an enhancement which incorporates a random mechanism at each boosting step showing an improvement in performance and speed in generating the ensemble. ada is an R package that implements three popular variants of boosting, together with a version of stochastic gradient boosting. In addition, useful plots for data analytic purposes are provided along with an extension to the multi-class case. The algorithms are illustrated with synthetic and real data sets.

  11. Detection of Illegitimate Emails using Boosting Algorithm

    DEFF Research Database (Denmark)

    2011-01-01

    In this paper, we report on experiments to detect illegitimate emails using boosting algorithm. We call an email illegitimate if it is not useful for the receiver or for the society. We have divided the problem into two major areas of illegitimate email detection: suspicious email detection...... and spam email detection. For our desired task, we have applied a boosting technique. With the use of boosting we can achieve high accuracy of traditional classification algorithms. When using boosting one has to choose a suitable weak learner as well as the number of boosting iterations. In this paper, we...

  12. Reweighting with Boosted Decision Trees

    CERN Document Server

    Rogozhnikov, A

    2016-01-01

    Machine learning tools are commonly used in modern high energy physics (HEP) experiments. Different models, such as boosted decision trees (BDT) and artificial neural networks (ANN), are widely used in analyses and even in the software triggers. In most cases, these are classification models used to select the "signal" events from data. Monte Carlo simulated events typically take part in training of these models. While the results of the simulation are expected to be close to real data, in practical cases there is notable disagreement between simulated and observed data. In order to use available simulation in training, corrections must be introduced to generated data. One common approach is reweighting - assigning weights to the simulated events. We present a novel method of event reweighting based on boosted decision trees. The problem of checking the quality of reweighting step in analyses is also discussed.

  13. Reweighting with Boosted Decision Trees

    Science.gov (United States)

    Rogozhnikov, Alex

    2016-10-01

    Machine learning tools are commonly used in modern high energy physics (HEP) experiments. Different models, such as boosted decision trees (BDT) and artificial neural networks (ANN), are widely used in analyses and even in the software triggers [1]. In most cases, these are classification models used to select the “signal” events from data. Monte Carlo simulated events typically take part in training of these models. While the results of the simulation are expected to be close to real data, in practical cases there is notable disagreement between simulated and observed data. In order to use available simulation in training, corrections must be introduced to generated data. One common approach is reweighting — assigning weights to the simulated events. We present a novel method of event reweighting based on boosted decision trees. The problem of checking the quality of reweighting step in analyses is also discussed.

  14. Totally Corrective Boosting for Regularized Risk Minimization

    CERN Document Server

    Shen, Chunhua; Barnes, Nick

    2010-01-01

    Consideration of the primal and dual problems together leads to important new insights into the characteristics of boosting algorithms. In this work, we propose a general framework that can be used to design new boosting algorithms. A wide variety of machine learning problems essentially minimize a regularized risk functional. We show that the proposed boosting framework, termed CGBoost, can accommodate various loss functions and different regularizers in a totally-corrective optimization fashion. We show that, by solving the primal rather than the dual, a large body of totally-corrective boosting algorithms can actually be efficiently solved and no sophisticated convex optimization solvers are needed. We also demonstrate that some boosting algorithms like AdaBoost can be interpreted in our framework--even their optimization is not totally corrective. We empirically show that various boosting algorithms based on the proposed framework perform similarly on the UCIrvine machine learning datasets [1] that we hav...

  15. Boosting equal time bound states

    CERN Document Server

    Dietrich, Dennis D; Jarvinen, Matti

    2012-01-01

    We present an explicit and exact boost of a relativistic bound state defined at equal time of the constituents in the Born approximation (lowest order in hbar). To this end, we construct the Poincar\\'e generators of QED and QCD in D=1+1 dimensions, using Gauss' law to express A^0 in terms of the fermion fields in A^1=0 gauge. We determine the fermion-antifermion bound states in the Born approximation as eigenstates of the time and space translation generators P^0 and P^1. The boost operator is combined with a gauge transformation so as to maintain the gauge condition A^1=0 in the new frame. We verify that the boosted state remains an eigenstate of P^0 and P^1 with appropriately transformed eigenvalues and determine the transformation law of the equal-time, relativistic wave function. The shape of the wave function is independent of the CM momentum when expressed in terms of a variable, which is quadratically related to the distance x between the fermions. As a consequence, the Lorentz contraction of the wave ...

  16. Boost Full Bridge Bidirectional DC/DC Converter for Supervised Aeronautical Applications

    Directory of Open Access Journals (Sweden)

    Alberto Cavallo

    2014-01-01

    Full Text Available The More Electrical Aircraft concept requires electronic devices able to efficiently and safely convert electrical power between different voltage levels. The entire realization of a bidirectional DC/DC converter, from design to validation phase, is here discussed in detail. First, a boost full bridge electrical structure is selected, adopting a Parallel Input Parallel Output (PIPO interleaving technique and an optimal turns ratio selection for the transformers in order to reduce both weight and size of the equipment. Next, modulation schemes in both step-down and step-up modes are discussed. Successively ad hoc PI regulators for both operative modes are presented. A key idea of the paper is that the converter behavior must be related not only to the control strategy but also to a global supervision logic able to safely conduct the converter operations and to react from external stimuli. Thus, a finite state machine (FSM approach is employed. An innovative strategy called buffer mode is presented, defined as an intelligent combination of buck and boost modes. Extensive simulations and experimental results are shown, in order to confirm the effectiveness of the proposed approach.

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

    Directory of Open Access Journals (Sweden)

    K. Rajambal

    2009-01-01

    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.

  18. Interleaved Buck Converter with Variable Number of Active Phases and a Predictive Current Sharing Scheme

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes; Garcia, O.; Oliver, J. A.

    2008-01-01

    The efficiency of an interleaved Buck converter is typically low at light load conditions because of the switching losses in each of the switching stages. Improvements in the converter efficiency can be achieved by dynamically changing the number of active phases depending on the load current...

  19. Dinucleotide repeat microsatellite markers for buck's-horn plantain (Plantago coronopus)

    NARCIS (Netherlands)

    Koorevaar, G.N.; Ivanovic, S.; Van Damme, J.M.M.; Koelewijn, H.P.; Van 't Westende, W.P.C.; Smulders, M.J.M.; Vosman, B.

    2002-01-01

    Eleven polymorphic microsatellite loci were obtained from a GA enriched genomic library, constructed from DNA of buck's-horn plantain (Plantago coronopus). The microsatellite loci were tested on 24 genotypes. These plants were collected from meadows along the coast, located on 11 sites ranging from

  20. "Class-Bucks": A Motivational Tool to Encourage Active Student Participation during Lectures

    Science.gov (United States)

    de Jager, T.

    2013-01-01

    The purpose of this study was to ascertain the influence of an extrinsic motivational tool, "class-bucks," on the possibility of improving first year student-teachers' participation in active learning at Tshwane University of Technology in South Africa. Research participants (n=289) were divided into four classes and engaged in this…

  1. Intensive hardwood log bucker training using HW Buck dramatically improves value recovery

    Science.gov (United States)

    James B. Pickens; Aaron Everett; Scott Noble; John E. Baumgras; Philip A. Araman; Conrad Waniger; Al Steele

    2006-01-01

    It has long been recognized that inappropriate placement of crosscuts when manufacturing hardwood logs from harvested stems (log bucking) reduces the value of logs produced. Recent studies have estimated losses in the range from 28% to 38% in the lake states region. It has not, however, been clear how to correct the problem. Efforts to improve value recovery have...

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

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.

    2007-01-01

    for traditional digital PWM modulators given a certain switching frequency. A synchronised version of the DiSOM modulator is derived for interleaved converters. A prototype interleaved Buck converter for Point of Load applications has been designed and built to test the performance of DiSOM modulator. The Di...

  3. Effect of Cage Type on Fecal Corticosterone Concentration in Buck Rabbits During the Reproductive Cycle.

    Science.gov (United States)

    Cornale, Paolo; Macchi, Elisabetta; Renna, Manuela; Prola, Liviana; Perona, Giovanni; Mimosi, Antonio

    2016-01-01

    Fecal corticosterone concentration (FCC) was measured in 14 buck rabbits individually housed in standard-dimension cages (SC) or in bigger cages (BC; with a volume more than double that of SC and equipped with a plastic foot mat) during 4 consecutive reproductive cycles. Cage type and reproductive phase (estrous synchronization of doe rabbits, artificial insemination, partum, preweaning, and postweaning) were not statistically significant but tendentially affected FCCs (.05 Buck rabbits housed in SC showed higher FCCs than those housed in BC (27.42 pg g(- 1) dried feces and 25.57 pg g(- 1), respectively; SEM = 2.952). The highest FCC values were detected at artificial insemination (BC, 27.91 pg g(- 1); SC, 30.45 pg g(- 1); SEM = 3.520), highlighting that the phase of semen collection could be one of the most critical moments for buck rabbits, although further investigations are needed. These preliminary results suggest that measurement of FCC could be used as an indicator of chronic stress in buck rabbits.

  4. Three Phase Six-Switch PWM Buck Rectifier with Power Factor Improvement

    DEFF Research Database (Denmark)

    Zafar Ullah Khan, M; Mohsin Naveed, M.; Hussain, Dil Muhammad Akbar

    2013-01-01

    Conventional Phase Controlled Rectifier injects low order current harmonics into the AC mains. Large size filtering components are required to attenuate these harmonics. In this paper, Three Phase Six-Switch PWM Buck Rectifier[1] is presented which operates at nearly unity power factor and provides...

  5. On the Behaviour of Current-Carrying Wire-Conductors and Bucking of a Column

    DEFF Research Database (Denmark)

    Ganji, S. S.; Barari, Amin; Fereidoon, A.

    2013-01-01

    -conductors and bucking of a column as well as their comparisons with the exact solutions are presented. Different specific parameters and initial values comprising the mass and stiffness are studied within the current research and excellent accuracy which is the most significant feature of the proposed solutions...

  6. Global analysis of a buck regulator. [for voltage using discrete control law

    Science.gov (United States)

    Edwards, D. B.; Caughey, T. K.

    1978-01-01

    Sufficient conditions for global stability of a buck regulator using a discrete control law are found. The method of paired systems and Liapunov functions are used to establish global stability and to study the convergence of the regulator. A heuristic argument is given that the optimal switching curves associated with the paired continuous systems approximate the optimal switching curves of the discrete systems.

  7. Three Phase Six-Switch PWM Buck Rectifier with Power Factor Improvement

    DEFF Research Database (Denmark)

    Zafar Ullah Khan, M; Mohsin Naveed, M.; Hussain, Dil Muhammad Akbar

    2013-01-01

    Conventional Phase Controlled Rectifier injects low order current harmonics into the AC mains. Large size filtering components are required to attenuate these harmonics. In this paper, Three Phase Six-Switch PWM Buck Rectifier[1] is presented which operates at nearly unity power factor and provid...

  8. No boundaries. Texas' Christus Health bucks trend by looking to Mexico for expansion.

    Science.gov (United States)

    Jaklevic, M C

    2001-08-06

    Christus Health has bucked the trend by looking to Mexico for expansion. The Roman Catholic system based in Irving, Texas, bought 51% of Hospital Muquerza in the prosperous northern Mexico state of Nuevo Leon. Christus believes the move makes sense on many levels.

  9. Pole placement method of controlling chaos in DC-DC buck converters

    Institute of Scientific and Technical Information of China (English)

    Zou Yan-Li; Luo Xiao-Shu; Chen Guan-Rong

    2006-01-01

    Based on the mechanism for the generation of chaos in a buck converter, a pole placement method is proposed and applied to controlling the chaos in a circuit. The control circuit is designed and tested. Numerical calculation and circuit implementation demonstrate the validity of this chaos control method.

  10. Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

    Directory of Open Access Journals (Sweden)

    Lourdes Gallego-Calvo

    2015-12-01

    Full Text Available Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001. No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05. After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05. These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer.

  11. Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

    Energy Technology Data Exchange (ETDEWEB)

    Gallego-Calvo, L.; Gatica, M.C.; Santiago-Moreno, J.; Guzmán, J.L.; Zarazaga, L.

    2015-07-01

    Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001). No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05). After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05). These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer. (Author)

  12. Recursive bias estimation and L2 boosting

    Energy Technology Data Exchange (ETDEWEB)

    Hengartner, Nicolas W [Los Alamos National Laboratory; Cornillon, Pierre - Andre [INRA, FRANCE; Matzner - Lober, Eric [RENNE, FRANCE

    2009-01-01

    This paper presents a general iterative bias correction procedure for regression smoothers. This bias reduction schema is shown to correspond operationally to the L{sub 2} Boosting algorithm and provides a new statistical interpretation for L{sub 2} Boosting. We analyze the behavior of the Boosting algorithm applied to common smoothers S which we show depend on the spectrum of I - S. We present examples of common smoother for which Boosting generates a divergent sequence. The statistical interpretation suggest combining algorithm with an appropriate stopping rule for the iterative procedure. Finally we illustrate the practical finite sample performances of the iterative smoother via a simulation study.

  13. Humanism in War—Analysis on Pearl S. Buck's War Outlook in Dragon Seed%Humanism in War—Analysis on Pearl S.Buck's War Outlook in Dragon Seed

    Institute of Scientific and Technical Information of China (English)

    张婷

    2015-01-01

    Pearl S.Buck is a controversial American writer.Dragon Seed is one of her war novels and arouses some readers'mis-understanding because of the vivid description of human loss.This research will focus on the analysis of the characters'person-ality change before and during the enemies'invasion.And then explore Pearl S.Buck's real attitude towards Chinese Anti-Japa-nese War and her buried war outlook.

  14. Bathymetry 1M Grid of St. Croix (Buck Island), US Virgin Islands 2005, UTM 20 NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains an ESRI Grid with 1 meter cell size representing the bathymetry of the north shore of St. Croix (Buck Island), US Virgin Islands. NOAA's...

  15. Bathymetry 1M GRID of St. Croix (Buck Island), US Virgin Islands, 2004, UTM 20 WGS84

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains an ESRI Grid with 1 meter cell size representing the bathymetry of the north shore of Buck Island St. Croix, US Virgin Islands. NOAA's...

  16. Avoidance High-Frequency Chattering Second-Order Sliding Mode Controller Design: Buck Converter in Wind Power System

    Directory of Open Access Journals (Sweden)

    Yigeng Huangfu

    2012-01-01

    Full Text Available This paper mainly discussed a method of high-frequency second-order sliding mode control for Buck converter in wind power systems. Because the wind energy of nature is always unpredictable and intermittent, the robust control such as sliding mode control is adopted in past literatures. In order to remove the high frequency chattering problem when the traditional sliding mode achieves convergence, the second order sliding mode algorithm is reviewed firstly. Meanwhile, the Buck converter taken as a step-down converter is usually adopted in wind power system, because of its simple structure and good linearity. Under those conditions, the second order sliding mode controller is designed based on Buck converter, especially in high-power wind generation system. The experimental results illustrate that the theory of second order sliding mode can be used in high-power Buck converter. It provides one novel avoidance high frequency chattering method for the technology development of new energy generation system.

  17. GeoTIFF of 3x3 m Bathymetry for Buck Island, St. Croix, 2011, UTM 20N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a LiDAR (Light Detection & Ranging) 3x3 meter resolution bathymetric surface for an area including and surrounding Buck Island Reef...

  18. NOAA TIFF Graphic- 0.5m Backscatter Mosaic of St. Croix (Buck Island), US Virgin Islands, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 1 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands.NOAA's NOS/NCCOS/CCMA Biogeography Team...

  19. NOAA TIFF Graphic- 0.5m Backscatter Mosaic of St. Croix (Buck Island), US Virgin Islands, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This geotiff represents a 0.5 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands.NOAA's NOS/NCCOS/CCMA Biogeography...

  20. NOAA ESRI Geotiff- 1m Bathymetry of St. Croix (Buck Island), US Virgin Islands, 2004, UTM 20 WGS84

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains an ESRI Geotiff with 1 meter cell size representing the bathymetry of the north shore of Buck Island St. Croix, US Virgin Islands.NOAA's...

  1. Face Alignment Using Boosting and Evolutionary Search

    NARCIS (Netherlands)

    Zhang, Hua; Liu, Duanduan; Poel, Mannes; Nijholt, Anton; Zha, H.; Taniguchi, R.-I.; Maybank, S.

    2010-01-01

    In this paper, we present a face alignment approach using granular features, boosting, and an evolutionary search algorithm. Active Appearance Models (AAM) integrate a shape-texture-combined morphable face model into an efficient fitting strategy, then Boosting Appearance Models (BAM) consider the f

  2. Boosted top: new algorithms and perspectives

    CERN Document Server

    Caudron, Julien; The ATLAS collaboration

    2017-01-01

    Studies of the boosted sector in top-quark physics have known a fast-growing development with the arrival of high-energy data at LHC. This presentation summarizes the current status of the boosted top-tagging techniques in ATLAS and CMS and presents an overview of the most noticeable developments.

  3. Boosting as a Product of Experts

    CERN Document Server

    Edakunni, Narayanan U; Kovacs, Tim

    2012-01-01

    In this paper, we derive a novel probabilistic model of boosting as a Product of Experts. We re-derive the boosting algorithm as a greedy incremental model selection procedure which ensures that addition of new experts to the ensemble does not decrease the likelihood of the data. These learning rules lead to a generic boosting algorithm - POE- Boost which turns out to be similar to the AdaBoost algorithm under certain assumptions on the expert probabilities. The paper then extends the POEBoost algorithm to POEBoost.CS which handles hypothesis that produce probabilistic predictions. This new algorithm is shown to have better generalization performance compared to other state of the art algorithms.

  4. ATLAS boosted object tagging 2

    CERN Document Server

    Caudron, Julien; The ATLAS collaboration

    2015-01-01

    A detailed study into the optimal techniques for identifying boosted hadronically decaying W or Z bosons is presented. Various algorithms for reconstructing, grooming and tagging bosonic jets are compared for W bosons with a wide range of transverse momenta using 8 TeV data and 8 TeV and 13 TeV MC simulations. In addition, given that a hadronic jet has been identified as resulting from the hadronic decay of a W or Z, a technique is developed to discriminate between W and Z bosons. The modeling of the tagging variables used in this technique is studied using 8 TeV pp collision data and systematic uncertainties for the tagger efficiency and fake rates are evaluated.

  5. Boosting human learning by hypnosis.

    Science.gov (United States)

    Nemeth, Dezso; Janacsek, Karolina; Polner, Bertalan; Kovacs, Zoltan Ambrus

    2013-04-01

    Human learning and memory depend on multiple cognitive systems related to dissociable brain structures. These systems interact not only in cooperative but also sometimes competitive ways in optimizing performance. Previous studies showed that manipulations reducing the engagement of frontal lobe-mediated explicit attentional processes could lead to improved performance in striatum-related procedural learning. In our study, hypnosis was used as a tool to reduce the competition between these 2 systems. We compared learning in hypnosis and in the alert state and found that hypnosis boosted striatum-dependent sequence learning. Since frontal lobe-dependent processes are primarily affected by hypnosis, this finding could be attributed to the disruption of the explicit attentional processes. Our result sheds light not only on the competitive nature of brain systems in cognitive processes but also could have important implications for training and rehabilitation programs, especially for developing new methods to improve human learning and memory performance.

  6. Dynamics and stabilization of peak current-mode controlled buck converter with constant current load

    Institute of Scientific and Technical Information of China (English)

    冷敏瑞; 周国华; 张凯暾; 李振华

    2015-01-01

    The discrete iterative map model of peak current-mode controlled buck converter with constant current load (CCL), containing the output voltage feedback and ramp compensation, is established in this paper. Based on this model the com-plex dynamics of this converter is investigated by analyzing bifurcation diagrams and the Lyapunov exponent spectrum. The effects of ramp compensation and output voltage feedback on the stability of the converter are investigated. Experimental results verify the simulation and theoretical analysis. The stability boundary and chaos boundary are obtained under the theoretical conditions of period-doubling bifurcation and border collision. It is found that there are four operation regions in the peak current-mode controlled buck converter with CCL due to period-doubling bifurcation and border-collision bifur-cation. Research results indicate that ramp compensation can extend the stable operation range and transfer the operating mode, and output voltage feedback can eventually eliminate the coexisting fast-slow scale instability.

  7. A Novel Soft-Switching Synchronous Buck Converter for Portable Applications

    Directory of Open Access Journals (Sweden)

    Anup Kumar Panda

    2008-01-01

    Full Text Available This paper proposes a zero-voltage-transition (ZVT pulse-width-modulated (PWM synchronous buck converter, which is designed to operate at low voltage and high efficiency typically required for portable systems. A new passive auxiliary circuit that allows the main switch to operate with zero-voltage switching has been incorporated in the conventional PWM synchronous buck converter. The operation principles and a detailed steady-state analysis of the ZVT-PWM synchronous converter implemented with the auxiliary circuit are presented. Besides, the main switch and all of the semiconductor devices operate under soft-switching conditions. Thus, the auxiliary circuit provides a larger overall efficiency. The feasibility of the auxiliary circuit is confirmed by simulation and experimental results.

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

    Directory of Open Access Journals (Sweden)

    R. Dhanasekaran

    2011-04-01

    Full Text Available Permanent Magnet Brushless DC Motor (PMBLDC is one of the best electrical drives that has increasing popularity, due to their high efficiency, reliability, good dynamic response and very low maintenance. This makes the interest of modeling an ideal PMBLDC motor and it’s associated Drive System in simple and lucid manner. In this paper the drive system is proposed with a buck converter topology. It has the advantages of reduced switching losses, low inductor power loss, reduced ripple by using a pi-filter, which in turn makes the DC link voltage to be stable. The modeling and simulation of the PMBLDC motor is done using the software package MATLAB/SIMULINK. The operation principle of the buck converter is analyzed and the simulation results are presented in this paper to verify the theoretical analysis.

  9. Design and realization of the BUCK converter based on anti-saturated PI controller

    Directory of Open Access Journals (Sweden)

    JIANG Lan

    2013-02-01

    Full Text Available A kind of anti-saturated digital PI regulator is designed and implemented based on DSP.This PI regulator was applied to the system design of voltage and current double-loop control in a BUCK converter and related experimental research was made in a 5.5 KW prototype machine.Experimental results show that the converter has good static and dynamic performances and the validity of the design of the PI regulator is verified.

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

    Directory of Open Access Journals (Sweden)

    Nahid Hematian

    2013-10-01

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

  11. Informational model verification of ZVS Buck quasi-resonant DC-DC converter

    Science.gov (United States)

    Vakovsky, Dimiter; Hinov, Nikolay

    2016-12-01

    The aim of the paper is to create a polymorphic informational model of a ZVS Buck quasi-resonant DC-DC converter for the modeling purposes of the object. For the creation of the model is applied flexible open standards for setting, storing, publishing and exchange of data in distributed information environment. The created model is useful for creation of many and different by type variants with different configuration of the composing elements and different inner model of the examined object.

  12. Level of nutrition affects semen characteristics and freezability of Malaysian bucks

    Directory of Open Access Journals (Sweden)

    Abdullah*, R. B.

    2015-06-01

    Full Text Available Feeding is a major problem in goat production in Malaysia particularly it affects reproductive efficiency of goats. This research was aimed to confirm the effect of improper nutrition and management practice on the buck?s fresh and frozen-thawed semen quality. Bucks were challenged nutritionally by the standard feeding (standard-nutrition and underfeeding (under-nutrition, i.e. inadequate daily requirement of Napier grass (Pennisetum purpureum and pelleted compound feed. Bucks from three different breeds (Jermasia n=4, Boer n=1 and Katjang n=1 were used for semen collection and semen freezing. The fresh semen quality was used as control. Fresh semen qualities, i.e. volume (ml/ejaculate, mass movement, concentration (?109/ml and motility (% were 0.48, 3.92, 3.97, 82.5 for Jermasia, 0.62, 4.00, 4.20, 86.00 for Boer, 0.55, 3.5, 5.35, 87.50 for Katjang, respectively while the values for frozen-thawed sperm motility for Jermasia, Boer and Katjang were 55.83, 66.00 and 67.50%, respectively. In comparison of the different nutritional regimes, for fresh semen qualities, i.e. volume (ml/ejaculate, mass movement, concentration (?109/ml and motility (% were 0.56, 4.00, 4.34 and 86.00 for standard-nutrition and 0.38, 3.50, 3.57 and 76.25 for under-nutrition, respectively, while the values for frozen-thawed sperm motility for standard-and under-nutrition were 63.33 and 46.25%, respectively. It is imperative that adequate nutrients in proper feeding be given serious attention to ensure the success of semen collection and semen freezing.

  13. Perancangan dan Simulasi Full Bridge Inverter Lima Tingkat dengan Dual Buck Converter Terhubung Jaringan Satu Fasa

    Directory of Open Access Journals (Sweden)

    Zamratul Fuadi

    2014-03-01

    Full Text Available Inverter merupakan perangkat elektronika daya yang berfungsi mengonversi sumber searah menjadi bolak-balik. Full bridge inverter adalah satu jenisnya yang mampu menghasilkan tegangan tiga tingkat jika menggunakan teknik modulasi unipolar. Penambahan sirkuit dual buck converter pada full bridge inverter mampu menghasilkan tegangan dalam lima tingkat. Dua saklar pada rangkaian dual buck converter switching pada frekuensi tinggi 20 kHz, sedangkan empat saklar pada full bridge inverter switching pada frekuensi rendah 50 Hz. Teknik modulasi in phase disposition PWM (PDPWM digunakan untuk mengatur penyalaan saklar dual buck converter. Keluaran inverter lima tingkat dibandingkan dengan tiga tingkat. Total harmonic distortion tegangan (THDV dan arus (THDi inverter lima tingkat bernilai 23.2281 % dan 23.0975 %, sedangkan inverter tiga tingkat sebesar 51.9302 % dan52.2458 %. Ketika daya 1004.08 watt disumbangkan ke jala-jala, inverter lima tingkat menghasilkan power factor senilai 0.99 dan THDi 4.1 %. Pada sumbangan daya yang sama, inverter tiga tingkat menghasilkan power factor sebesar 0.919 dan THDi bernilai 45.64 %.

  14. Whole-body Response for Pedestrian Impact with a Generic Sedan Buck.

    Science.gov (United States)

    Forman, Jason L; Joodaki, Hamad; Forghani, Ali; Riley, Patrick O; Bollapragada, Varun; Lessley, David J; Overby, Brian; Heltzel, Sara; Kerrigan, Jason R; Crandall, Jeff R; Yarboro, Seth; Weiss, David B

    2015-11-01

    To serve as tools for assessing injury risk, the biofidelity of whole-body pedestrian impact dummies should be validated against reference data from full-scale pedestrian impact tests. To facilitate such evaluations, a simplified generic vehicle-buck has been recently developed that is designed to have characteristics representative of a generic small sedan. Three 40 km/h pedestrian-impact tests have been performed, wherein Post Mortem Human Surrogates (PMHS) were struck laterally in a mid-gait stance by the buck. Corridors for select trajectory measures derived from these tests have been published previously. The goal of this study is to act as a companion dataset to that study, describing the head velocities, body region accelerations (head, spine, pelvis, lower extremities), angular velocities, and buck interaction forces, and injuries observed during those tests. Scaled, transformed head accelerations exceeded 80 g prior to head contact with the windshield for two of the three tests. Head xaxis angular velocity exceeded 40 rad/s prior to head contact for all three tests. In all cases the peak resultant head velocity relative to the vehicle was greater than the initial impact speed of the vehicle. Corridors of resultant head velocity relative to the vehicle were also developed, bounded by the velocities observed in these tests combined with those predicted to occur if the PMHS necks were perfectly rigid. These results, along with the other kinematic and kinetic data presented, provide a resource for future pedestrian dummy development and evaluation.

  15. In vivo adverse effects of alpha-tocopherol on the semen quality of male bucks.

    Science.gov (United States)

    Majid, A; Qureshi, M S; Khan, R U

    2015-10-01

    Oxidative stress has detrimental effects on semen quality during spermatogenesis and semen processing for artificial insemination. This work was conducted to study the effect of different levels of vitamin E on the semen traits, oxidative status and trace minerals in Beetal bucks. Thirty-six bucks of similar body weight and age (1 year) were randomly divided into four groups. One group was kept as control with no supplementation (group 1), and the others were supplemented with 200 (group 2), 400 (group 3) and 800 IU (group 4) vitamin E/animal/day for 2 months. At the end of the experiment, semen samples were collected and evaluated. Seminal plasma was separated to study the concentration of superoxide dismutase (SOD), glutathione peroxidase (GPx), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and trace minerals (Zn, Cu, Mn and Fe). Group 3 showed significantly higher (p Zn, Cu and Mn were higher in the same group. The level of AST decreased in group 3 without any change on the concentration of ALT. It is suggested that vitamin E at the rate of 400 IU/buck/day supported higher semen volume, per cent motility, per cent live spermatozoa, antioxidants (SOD, GPx) and trace mineral levels (Zn, Cu, Mn) in the seminal plasma. The increased supplementation from 0 to 400 showed a general increasing trend in improving semen quality. However, the dose of 800 IU/kg had no useful effect in further improving the semen quality.

  16. A BOOSTING APPROACH FOR INTRUSION DETECTION

    Institute of Scientific and Technical Information of China (English)

    Zan Xin; Han Jiuqiang; Zhang Junjie; Zheng Qinghua; Han Chongzhao

    2007-01-01

    Intrusion detection can be essentially regarded as a classification problem,namely,distinguishing normal profiles from intrusive behaviors.This paper introduces boosting classification algorithm into the area of intrusion detection to learn attack signatures.Decision tree algorithm is used as simple base learner of boosting algorithm.Furthermore,this paper employs the Principle Component Analysis(PCA)approach,an effective data reduction approach,to extract the key attribute set from the original high-dimensional network traffic data.KDD CUP 99 data set is used in these exDeriments to demonstrate that boosting algorithm can greatly improve the clas.sification accuracy of weak learners by combining a number of simple"weak learners".In our experiments,the error rate of training phase of boosting algorithm is reduced from 30.2%to 8%after 10 iterations.Besides,this Daper also compares boosting algorithm with Support Vector Machine(SVM)algorithm and shows that the classification accuracy of boosting algorithm is little better than SVM algorithm's.However,the generalization ability of SVM algorithm is better than boosting algorithm.

  17. Riemann curvature of a boosted spacetime geometry

    Science.gov (United States)

    Battista, Emmanuele; Esposito, Giampiero; Scudellaro, Paolo; Tramontano, Francesco

    2016-10-01

    The ultrarelativistic boosting procedure had been applied in the literature to map the metric of Schwarzschild-de Sitter spacetime into a metric describing de Sitter spacetime plus a shock-wave singularity located on a null hypersurface. This paper evaluates the Riemann curvature tensor of the boosted Schwarzschild-de Sitter metric by means of numerical calculations, which make it possible to reach the ultrarelativistic regime gradually by letting the boost velocity approach the speed of light. Thus, for the first time in the literature, the singular limit of curvature, through Dirac’s δ distribution and its derivatives, is numerically evaluated for this class of spacetimes. Moreover, the analysis of the Kretschmann invariant and the geodesic equation shows that the spacetime possesses a “scalar curvature singularity” within a 3-sphere and it is possible to define what we here call “boosted horizon”, a sort of elastic wall where all particles are surprisingly pushed away, as numerical analysis demonstrates. This seems to suggest that such “boosted geometries” are ruled by a sort of “antigravity effect” since all geodesics seem to refuse to enter the “boosted horizon” and are “reflected” by it, even though their initial conditions are aimed at driving the particles toward the “boosted horizon” itself. Eventually, the equivalence with the coordinate shift method is invoked in order to demonstrate that all δ2 terms appearing in the Riemann curvature tensor give vanishing contribution in distributional sense.

  18. Homosexual behavior in male goats is more frequent during breeding season and in bucks isolated from females.

    Science.gov (United States)

    Ungerfeld, Rodolfo; Giriboni, Julia; Freitas-de-Melo, Aline; Lacuesta, Lorena

    2014-05-01

    Male homosexual behavior is observed in many ruminant species; seasonality and isolation from females may affect the display of male-male sexual behavior. Our objectives were to determine whether: 1) homosexual behavior has a seasonal pattern in male goats (Capra hircus); 2) isolation from female goats influences the frequency of the display of homosexual behavior; and 3) the frequency of homosexual behaviors is related to testosterone concentration. Bucks were housed in a pen adjacent to another pen with 3 estrous goats (FC group) or in complete isolation from females (IF group). Homosexual behaviors and testosterone concentrations were recorded in October, December, February and May. Frequencies of penile display and flehmen increased in May and were observed more frequently in the IF than in the FC group. Ano-genital sniffing was more frequent in February and May and was more frequent in IF than in FC bucks. Lateral approaches were more frequent in May, in which period this was more frequently observed in IF bucks. Mount attempts and mounts were only observed in IF bucks. Testosterone concentrations increased from December to February and decreased in May, although they were still greater than in October and December. In May IF bucks had greater testosterone concentrations than FC bucks. Testosterone concentrations were only related to the number of lateral approaches in IF bucks in December. In conclusion, homosexual behavior was more frequent during the late breeding season than during the early and the non-breeding seasons, and in males isolated from females than in males housed near estrous females. Testosterone concentrations appear to be unrelated to homosexual behavior.

  19. Multiphase boosting: A growing technology for the challenge of economical deepwater developments

    Energy Technology Data Exchange (ETDEWEB)

    Colombi, P. [Agip S.p.A., Milan (Italy); Chiesa, G. [Snamprogetti S.p.A., Milan (Italy); Aggradi, G.F. [Nuovo Pignone, Florence (Italy)

    1996-12-31

    The current operating success in the subsea prototype testing and the level of development of different pump concepts are promoting multiphase boosting as a reliable technology for the exploitation of subsea fields. From a situation where very basic questions were asked about the expected performance and reliability of this equipment the Industry is now looking at those scenarios showing the greatest potential for the application of this technology like the deep waters. Competitive options to develop subsea fields, however, may be available and, although they may present some disadvantages compared with multiphase boosting, they make use of traditional practices and proven technologies. In the above perspective, the field operational experience plays a key role to prove the suitability of the proposed systems in handling the untreated well fluids under real subsea conditions so giving multiphase boosting a distinct edge over more conventional solutions. To this end, the paper reviews the main results obtained so far by the underwater testing campaign of a prototype multiphase boosting unit at the Agip Prezioso Field, offshore Sicily. In particular, the review addresses the main technological issues encountered during the subsea operation of the boosting unit together with an initial characterization of the experienced unit performance. The above is considered to provide a significant contribution to the evaluation of the current level of maturity of this technology as well as of the present technological gap to meet the requirements posed by real industrial applications, particularly in deep waters.

  20. Boosting Wigner's nj-symbols

    CERN Document Server

    Speziale, Simone

    2016-01-01

    We study the SL(2,C) Clebsch-Gordan coefficients appearing in the lorentzian EPRL spin foam amplitudes for loop quantum gravity. We show how the amplitudes decompose into SU(2) nj-symbols at the vertices and integrals over boosts at the edges. The integrals define edge amplitudes that can be evaluated analytically using and adapting results in the literature, leading to a pure state sum model formulation. This procedure introduces virtual representations which, in a manner reminiscent to virtual momenta in Feynman amplitudes, are off-shell of the simplicity constraints present in the theory, but with the integrands that peak at the on-shell values. We point out some properties of the edge amplitudes which are helpful for numerical and analytical evaluations of spin foam amplitudes, and suggest among other things a simpler model useful for calculations of certain lowest order amplitudes. As an application, we estimate the large spin scaling behaviour of the simpler model, on a closed foam with all 4-valent edg...

  1. Boosting Wigner's nj-symbols

    Science.gov (United States)

    Speziale, Simone

    2017-03-01

    We study the SL (2 ,ℂ ) Clebsch-Gordan coefficients appearing in the Lorentzian EPRL spin foam amplitudes for loop quantum gravity. We show how the amplitudes decompose into SU(2) nj- symbols at the vertices and integrals over boosts at the edges. The integrals define edge amplitudes that can be evaluated analytically using and adapting results in the literature, leading to a pure state sum model formulation. This procedure introduces virtual representations which, in a manner reminiscent of virtual momenta in Feynman amplitudes, are off-shell of the simplicity constraints present in the theory, but with the integrands that peak at the on-shell values. We point out some properties of the edge amplitudes which are helpful for numerical and analytical evaluations of spin foam amplitudes, and suggest among other things a simpler model useful for calculations of certain lowest order amplitudes. As an application, we estimate the large spin scaling behaviour of the simpler model, on a closed foam with all 4-valent edges and Euler characteristic χ , to be Nχ -5 E +V /2. The paper contains a review and an extension of the results on SL (2 ,ℂ ) Clebsch-Gordan coefficients among unitary representations of the principal series that can be useful beyond their application to quantum gravity considered here.

  2. Permanent Magnet Boosted Modular Switched Reluctance Motor

    Directory of Open Access Journals (Sweden)

    SZABÓ Loránd

    2016-10-01

    Full Text Available This paper deals with the analyses of a novel motor structure obtained by boosting with permanent magnets a formerly studied modular switched reluctance motor. Upon dynamic simulation results the improvements of the proposed motor are emphasized.

  3. Riemann curvature of a boosted spacetime geometry

    CERN Document Server

    Battista, Emmanuele; Scudellaro, Paolo; Tramontano, Francesco

    2014-01-01

    The ultrarelativistic boosting procedure had been applied in the literature to map the metric of Schwarzschild-de Sitter spacetime into a metric describing de Sitter spacetime plus a shock-wave singularity located on a null hypersurface. This paper evaluates the Riemann curvature tensor of the boosted Schwarzschild-de Sitter metric by means of numerical calculations, which make it possible to reach the ultrarelativistic regime gradually by letting the boost velocity approach the speed of light. Thus, for the first time in the literature, the singular limit of curvature through Dirac's delta distribution and its derivatives is numerically evaluated for this class of spacetimes. Eventually, the analysis of the Kteschmann invariant and the geodesic equation show that the spacetime possesses a scalar curvature singularity within a 3-sphere and it is possible to define what we here call boosted horizon, a sort of elastic wall where all particles are surprisingly pushed away, as numerical analysis demonstrates. Thi...

  4. Improving fruit and vegetable consumption among low-income customers at farmers markets: Philly Food Bucks, Philadelphia, Pennsylvania, 2011.

    Science.gov (United States)

    Young, Candace R; Aquilante, Jennifer L; Solomon, Sara; Colby, Lisa; Kawinzi, Mukethe A; Uy, Nicky; Mallya, Giridhar

    2013-10-03

    We evaluated whether Philly Food Bucks, a bonus incentive program at farmers markets, is associated with increased fruit and vegetable consumption and Supplemental Nutrition Assistance Program (SNAP) sales at farmers markets in low-income areas. A convenience sample of 662 customers at 22 farmers markets in low-income neighborhoods in Philadelphia, Pennsylvania, was surveyed via face-to-face interviews. Questions addressed shopping characteristics, self-reported change in fruit and vegetable consumption, whether customers tried new fruits or vegetables, use of Philly Food Bucks, and demographic information. Market-level SNAP sales and Philly Food Bucks redemption data were also collected to monitor sales patterns. Philly Food Bucks users were significantly more likely than nonusers to report increasing fruit and vegetable consumption (OR, 2.4; 95% CI, 1.6-3.7; P Food Bucks program. At the city's largest farmers market in a low-income area, the program was associated with an almost 5-fold higher increase in annual SNAP sales compared with baseline. Results from this study demonstrate that a bonus incentive program tied to SNAP was associated with self-reported increases in fruit and vegetable consumption and increased SNAP sales at participating farmers markets in low-income communities. More research is warranted to evaluate the long-term impact of bonus incentives on farmers market use, dietary behaviors, and health outcomes.

  5. Top reconstruction and boosted top experimental overview

    CERN Document Server

    Skinnari, Louise

    2015-01-01

    An overview of techniques used to reconstruct resolved and boosted top quarks is presented. Techniques for resolved top quark reconstruction include kinematic likelihood fitters and pseudo- top reconstruction. Many tools and methods are available for the reconstruction of boosted top quarks, such as jet grooming techniques, jet substructure variables, and dedicated top taggers. Different techniques as used by ATLAS and CMS analyses are described and the performance of different variables and top taggers are shown.

  6. Boosted regression tree, table, and figure data

    Science.gov (United States)

    Spreadsheets are included here to support the manuscript Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition. This dataset is associated with the following publication:Golden , H., C. Lane , A. Prues, and E. D'Amico. Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition. JAWRA. American Water Resources Association, Middleburg, VA, USA, 52(5): 1251-1274, (2016).

  7. Flexible boosting of accelerated failure time models

    Directory of Open Access Journals (Sweden)

    Hothorn Torsten

    2008-06-01

    Full Text Available Abstract Background When boosting algorithms are used for building survival models from high-dimensional data, it is common to fit a Cox proportional hazards model or to use least squares techniques for fitting semiparametric accelerated failure time models. There are cases, however, where fitting a fully parametric accelerated failure time model is a good alternative to these methods, especially when the proportional hazards assumption is not justified. Boosting algorithms for the estimation of parametric accelerated failure time models have not been developed so far, since these models require the estimation of a model-specific scale parameter which traditional boosting algorithms are not able to deal with. Results We introduce a new boosting algorithm for censored time-to-event data which is suitable for fitting parametric accelerated failure time models. Estimation of the predictor function is carried out simultaneously with the estimation of the scale parameter, so that the negative log likelihood of the survival distribution can be used as a loss function for the boosting algorithm. The estimation of the scale parameter does not affect the favorable properties of boosting with respect to variable selection. Conclusion The analysis of a high-dimensional set of microarray data demonstrates that the new algorithm is able to outperform boosting with the Cox partial likelihood when the proportional hazards assumption is questionable. In low-dimensional settings, i.e., when classical likelihood estimation of a parametric accelerated failure time model is possible, simulations show that the new boosting algorithm closely approximates the estimates obtained from the maximum likelihood method.

  8. Pengaruh Pencucian Sperma dengan Lama Waktu Sentrifugasi yang Berbeda Terhadap Kualitas Sperma Kambing Bligon (Effect of Sperm Washing with Different Centrifugation Duration on Sperm Quality of Bligon Buck

    Directory of Open Access Journals (Sweden)

    Sigit Bintara

    2012-02-01

    spermatozoa. It is concluded that washing Bligon buck sperm using SpermRinse with centrifugation at 1.500 rpm (r = 5.5 cm could increased sperm quality, of which 20 minutes was the best centrifugation time. (Key word: Bligon Buck, Sperm, SpermRinse, Sperm quality

  9. A novel single phase buck PFC converter in discontinuous capacitor voltage mode operation

    Institute of Scientific and Technical Information of China (English)

    邓超平; 凌志斌; 叶芃生

    2003-01-01

    A novel single-phase Buck converter for power factor correction is proposed. It features simple control due to the constant duty ratio PWM used. It can obtain unity power factor by selecting a suitable LC filter at its input to force the voltage of capacitor to operate in discontinuous capacitor voltage mode. And by using another resonant LC filter at its output, it can not only eliminate the input current distortion at the vicinity of the zero crossing of the supply but also drastically reduce the 100 Hz output voltage ripple. The validity of analysis is confirmed by simulation results and experimental results.

  10. On Some Extensions of Szasz Operators Including Boas-Buck-Type Polynomials

    Directory of Open Access Journals (Sweden)

    Sezgin Sucu

    2012-01-01

    Full Text Available This paper is concerned with a new sequence of linear positive operators which generalize Szasz operators including Boas-Buck-type polynomials. We establish a convergence theorem for these operators and give the quantitative estimation of the approximation process by using a classical approach and the second modulus of continuity. Some explicit examples of our operators involving Laguerre polynomials, Charlier polynomials, and Gould-Hopper polynomials are given. Moreover, a Voronovskaya-type result is obtained for the operators containing Gould-Hopper polynomials.

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

    Institute of Scientific and Technical Information of China (English)

    QIN Zhi-Ying; LU Qi-Shao

    2007-01-01

    A direct-current-dorect-current (DC-DC)buck converter with integrated load current feedback is studied with three kinds of Poicaré 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 l-band chaos.A new kind of chaotic sliding orbits,which is more complex for non-smooth systems,is also found in this model.

  12. Bucking Coil Implementation on PMT for Active Cancelling of Magnetic Field

    CERN Document Server

    Gogami, T; Bono, J; Baturin, P; Chen, C; Chiba, A; Chiga, N; Fujii, Y; Hashimoto, O; Kawama, D; Maruta, T; Maxwell, V; Mkrtchyan, A; Nagao, S; Nakamura, S N; Reinhold, J; Shichijo, A; Tang, L; Taniya, N; Wood, S A; Ye, Z

    2013-01-01

    Aerogel and water Cerenkov detectors were employed to tag kaons for a lambda hypernuclear spectroscopic experiment which used the (e,e'K+) reaction in experimental Hall C at Jefferson Lab (JLab E05-115). Fringe fields from the kaon spectrometer magnet yielded ~5 Gauss at the photomultiplier tubes (PMT) for these detectors which could not be easily shielded. As this field results in a lowered kaon detection efficiency, we implemented a bucking coil on each photomultiplier tubes to actively cancel this magnetic field, thus maximizing kaon detection efficiency.

  13. A Simple Method for Reducing the Transient Oscillation in Single-Phase Buck Rectifiers

    Science.gov (United States)

    Wakakuwa, Yukihiro; Motegi, Shin-Ich; Yoshida, Toshiya; Miyashita, Osamu

    The single-phase buck rectifier has several advantages, such as the controllability of lower dc output voltages, and negligible inrush input-current at start-up. However, the rectifier requires an LC-filter connected on the input side of the switching device to absorb the harmonics caused by the on and off behavior. The LC-filter involves an LC resonance in transient states. To solve this problem, a suppression approach using only a series RLC circuit, which selectively acts as a damping at around the resonant frequency, is proposed. Simulation and experimental results confirm the validity of this method.

  14. Sensorless load torque estimation and passivity based control of buck converter fed DC motor.

    Science.gov (United States)

    Kumar, S Ganesh; Thilagar, S Hosimin

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    S. Ganesh Kumar

    2015-01-01

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

  16. Reliability-Oriented Optimization of the LC Filter Design of a Buck DC-DC Converter

    DEFF Research Database (Denmark)

    Liu, Yi; Huang, Meng; Wang, Huai

    2017-01-01

    Lifetime is an important performance factor in the reliable operation of power converters. However, the state-of-the-art LC filter design of a buck DC-DC converter is limited to the specifications of voltage and current ripples and constrains in power density and cost without reliability...... considerations. This paper proposes a method to optimize the design of the LC filters from a reliability perspective, besides other considerations. An enhanced model is derived to quantify the lifetime of the capacitor in the filter considering the electro-thermal stress on it. Furthermore, the influence...

  17. The effect of semen collection method and level of egg yolk on capability of dilution and storage of buck semen

    Directory of Open Access Journals (Sweden)

    N.N. Dhaher

    2013-12-01

    Full Text Available The study was conducted to evaluate the effect of semen collection method for reduction of the deleterious interaction between the enzymes of bulbourethral gland and egg yolk during the dilution and storage of buck semen by three different level of egg yolk. Ten bucks were used in this study; the bucks were divided into two groups (five bucks in each group. Semen samples were collected once a week for four weeks from the bucks in first group using an artificial vagina, and from the animals in second group using an electroejaculator. The collected semen samples were diluted with sodium citrate extender with three different level of egg yolk (5, 10 and 20%. Extend semen samples were stored at 5 °C for three days. Computer assisted sperm analysis and Sperm Class Analyzer® were used for evaluation of the buck semen samples. Sperm motility parameters were evaluated which includes; percentage of motile sperm, percentage of progressive motile sperm, the value of the linear velocity (VSL, the value of the average velocity (VAP, the value of the curvilinear velocity (VCL, and the amplitude of lateral movement of the head (ALH. Results showed that all sperm motility parameters under the different level of egg yolk in semen samples that collected by artificial vagina were significantly higher than those which collected by electroejaculator. The percentage of motile sperm and progressive motile sperm of samples that collected by artificial vagina were higher at 10% of egg yolk, while these motility parameters were higher at 5% of egg yolk for semen samples that collected by electroejaculator. The differences between the two methods of semen collection in VCL and ALH were clear and the values were higher in samples that collected using the artificial vagina. The values of VSL, VAP and VCL of semen samples that collected by artificial vagina were higher at the second day than first day of semen storage under 10% of egg yolk. In conclusion, there are effects

  18. Historical and Current U.S. Strategies for Boosting Distributed Generation

    Energy Technology Data Exchange (ETDEWEB)

    Lowder, Travis [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schwabe, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhou, Ella [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arent, Douglas J. [Joint Inst. for Strategic Energy Analysis, Golden, CO (United States)

    2015-10-29

    This report seeks to introduce a variety of top-down and bottom-up practices that, in concert with the macro-environment of cost-reduction globally and early adoption in Europe, helped boost the distributed generation photovoltaic market in the United States. These experiences may serve as a reference in China's quest to promote distributed renewable energy.

  19. Positive Semidefinite Metric Learning with Boosting

    CERN Document Server

    Shen, Chunhua; Wang, Lei; Hengel, Anton van den

    2009-01-01

    The learning of appropriate distance metrics is a critical problem in image classification and retrieval. In this work, we propose a boosting-based technique, termed \\BoostMetric, for learning a Mahalanobis distance metric. One of the primary difficulties in learning such a metric is to ensure that the Mahalanobis matrix remains positive semidefinite. Semidefinite programming is sometimes used to enforce this constraint, but does not scale well. \\BoostMetric is instead based on a key observation that any positive semidefinite matrix can be decomposed into a linear positive combination of trace-one rank-one matrices. \\BoostMetric thus uses rank-one positive semidefinite matrices as weak learners within an efficient and scalable boosting-based learning process. The resulting method is easy to implement, does not require tuning, and can accommodate various types of constraints. Experiments on various datasets show that the proposed algorithm compares favorably to those state-of-the-art methods in terms of classi...

  20. Tratamento da espondilólise sintomática com reparo direto pela técnica de Buck modificada Tratamiento de la espondilolisis sintomática con preparo directo por la técnica de Buck modificada Modified Buck's direct repair to simptomatic spondylolysis treatment

    OpenAIRE

    Bruno Pinto Coelho Fontes; Maurício Erwin Pühler Resende; Carlos Moreira Rezende; Rodrigo D'Alessandro de Macedo; Luis Olímpio Garcia Pedrosa; Jefferson Soares Leal; Rogério Lúcio Chaves de Resende

    2009-01-01

    OBJETIVO: justificar a reconstrução da pars interarticularis pela técnica modificada de Buck como método efetivo no tratamento de lombalgia por espondilólise ou espondilolistese tipo 1, refratárias ao tratamento conservador. MÉTODOS: avaliação retrospectiva de oito pacientes com idade entre 11 e 34 anos, operados e acompanhados no período de outubro de 2004 a maio de 2008 com a técnica de Buck utilizando-se parafusos canulados de titânio. Nenhum paciente foi imobilizado no pós-operatório. Os ...

  1. Behavior of Werner states under relativistic boosts

    Science.gov (United States)

    Palge, Veiko; Dunningham, Jacob

    2015-12-01

    We study the structure of maps that Lorentz boosts induce on the spin degree of freedom of a system consisting of two massive spin- 1 / 2 particles. We consider the case where the spin state is described by the Werner state and the momenta are discrete. Transformations on the spins are systematically investigated in various boost scenarios by calculating the orbit and concurrence of the bipartite spin state with different kinds of product and entangled momenta. We confirm the general conclusion that Lorentz boosts cause non-trivial behavior of bipartite spin entanglement. Visualization of the evolution of the spin state is shown to be valuable in explaining the pattern of concurrence. The idealized model provides a basis of explanation in terms of which phenomena in systems involving continuous momenta can be understood.

  2. Improved Stereo Matching With Boosting Method

    Directory of Open Access Journals (Sweden)

    Shiny B

    2015-06-01

    Full Text Available Abstract This paper presents an approach based on classification for improving the accuracy of stereo matching methods. We propose this method for occlusion handling. This work employs classification of pixels for finding the erroneous disparity values. Due to the wide applications of disparity map in 3D television medical imaging etc the accuracy of disparity map has high significance. An initial disparity map is obtained using local or global stereo matching methods from the input stereo image pair. The various features for classification are computed from the input stereo image pair and the obtained disparity map. Then the computed feature vector is used for classification of pixels by using GentleBoost as the classification method. The erroneous disparity values in the disparity map found by classification are corrected through a completion stage or filling stage. A performance evaluation of stereo matching using AdaBoostM1 RUSBoost Neural networks and GentleBoost is performed.

  3. A current-mode DC-DC buck converter with adaptive zero compensation

    Institute of Scientific and Technical Information of China (English)

    Yang Ling; Dai Guoding; Xu Chongwei; Liu Yuezhi

    2013-01-01

    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 currentmode DC-DC buck converter with the proposed structure has been implemented in a 0.35 μm CMOS process,and the die size is only 800 × 1040 μm2.The experimental results show that the transient undershoot/overshoot voltage and the recovery times do not exceed 40 mV and 30 μs for a load current variation from 100 mA to 1 A.

  4. Performance Analysis of Trench Power MOSFETs in High-Frequency Synchronous Buck Converter Applications

    Directory of Open Access Journals (Sweden)

    Yali Xiong

    2008-01-01

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

  5. Uranium occurrences in Bucks County, Pennsylvania, and Hunterdon County, New Jersey

    Science.gov (United States)

    McKeown, F.A.; Choquette, P.W.; Baker, R.C.

    1954-01-01

    Eleven occurrences of uraniferous argillite in the Lockatong lithofacies and five occurrences of uraniferous sandstone in the Stockton lithofacies, both of Triassic age, are known in Buck County, Pa. and Hunterdon County, N.J. Most of the occurrences were discovered by the Geological Survey, though prospectors found several. The Delaware quarry, Bucks County, Pa., was mapped and sampled in detail because the best exposed and most uraniferous argillite known crops out there. Sketches of two sandstone occurrences were made. Two stratigraphic sections of part of the Stockton formation were made in an unsuccessful effort to find key beds to which the uranium occurrences might be referred. The argillite occurrences contain as much as 0.034 percent uranium but commonly contain only about 0.010 percent uranium. They are known to extend for several hundred feet along the strike and may possibly extend several thousand feet, but less than a mile. They range from about 1 to 6 feet in thickness. The sandstone occurrences are characterized by the presence of pyrite or limonite and the alteration of feldspar to clay. The most uraniferous parts of the sandstone contain mud pebbles or lenses. The sandstone with mud pellets generally contain from 0.01 to 0.03 percent uranium, but selected parts of the pellets contain as much as 0.29 percent uranium. The known occurrences are small, about 1 to 2 feet thick and 20 to 30 feet long. None of the argillite or sandstone occurrences are now of economic importance.

  6. Dynamics and stabilization of peak current-mode controlled buck converter with constant current load

    Science.gov (United States)

    Leng, Min-Rui; Zhou, Guo-Hua; Zhang, Kai-Tun; Li, Zhen-Hua

    2015-10-01

    The discrete iterative map model of peak current-mode controlled buck converter with constant current load (CCL), containing the output voltage feedback and ramp compensation, is established in this paper. Based on this model the complex dynamics of this converter is investigated by analyzing bifurcation diagrams and the Lyapunov exponent spectrum. The effects of ramp compensation and output voltage feedback on the stability of the converter are investigated. Experimental results verify the simulation and theoretical analysis. The stability boundary and chaos boundary are obtained under the theoretical conditions of period-doubling bifurcation and border collision. It is found that there are four operation regions in the peak current-mode controlled buck converter with CCL due to period-doubling bifurcation and border-collision bifurcation. Research results indicate that ramp compensation can extend the stable operation range and transfer the operating mode, and output voltage feedback can eventually eliminate the coexisting fast-slow scale instability. Project supported by the National Natural Science Foundation of China (Grant No. 61371033), the Fok Ying-Tung Education Foundation for Young Teachers in the Higher Education Institutions of China (Grant No. 142027), the Sichuan Provincial Youth Science and Technology Fund, China (Grant Nos. 2014JQ0015 and 2013JQ0033), and the Fundamental Research Funds for the Central Universities, China (Grant No. SWJTU11CX029).

  7. Boosted top production in ATLAS and CMS

    CERN Document Server

    Romano, Marino; The ATLAS collaboration

    2017-01-01

    An overview of the boosted top production analyses using data collected by the ATLAS and CMS experiments at $\\sqrt{s}=$' 8 TeV and 13 TeV of proton-proton collisions at the LHC is presented. These analyses use techniques for the reconstruction of boosted objects to measure the production of top quarks at high transverse momenta. The measurements are optimized for the different final states and for different ranges of the transverse momenta of the particles involved, improving on measurements with traditional objects reconstruction based on the combination of resolved objects.

  8. Entanglement asymmetry for boosted black branes

    CERN Document Server

    Mishra, Rohit

    2016-01-01

    We study the effects of asymmetry in entanglement thermodynamics of the CFT subsystems. It is found that `boosted' $p$-branes backgrounds give rise to the first law of the entanglement thermodynamics where the CFT pressure plays decisive role in the entanglement. Two different strip like subsystems, one parallel to the boost and the other perpendicular, are studied in the perturbative regime, where $T_{thermal}\\ll T_E$. We also discuss the AdS-wave backgrounds where some universal bounds can be obtained.

  9. Semen characteristics and sexual hormones of Hy-Plus rabbit bucks influenced by a dietary multi-enzymes additive

    Directory of Open Access Journals (Sweden)

    H. Gado

    2015-06-01

    Full Text Available A total of 144 adult Hy-Plus rabbit bucks were randomly assigned into  four treatments of 36 replicates each, in a completely randomized design. Animals were fed ad libitum on basal diet supplemented with an enzyme complex (EZ at 0 (EZ0, 1 (EZ1, 3 (EZ3 and 5 (EZ5 kg/ton of feed. Total sperm count was higher (P<0.05 in EZ5 than in EZ0. Sperm motility increased with increasing levels of the EZ additive being lowest for EZ0 and highest for EZ5 rabbits (P<0.05. Percentage of dead sperm was higher (P<0.05 in EZ0 than in EZ5 rabbits. Rabbit bucks received the highest levele of EZ in their diet, had the shorter reaction time (22.31±3.17 sec; P<0.05,whereas EZ5 bucks took 43.56±5.89 sec to mount does for the first time after exposure. Blood testosterone, 17α-estradiol and progesterone levels were highest in EZ5 rabbits and lowest in EZ0 rabbits. Enzyme addition increased (P<0.05 sperm transit in estrus doe cervical mucus. Data suggested that the EZ additive in diets of  adult Hy-Plus rabbit bucks was effective to improve both semen characteristics and sexual drive.

  10. Monolithic quasi-sliding-mode controller for SIDO buck converter with a self-adaptive free-wheeling current level

    Institute of Scientific and Technical Information of China (English)

    Wu Xiaobo; Liu Qing; Zhao Menglian; Chen Mingyang

    2013-01-01

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

  11. Almost Redundant Components in the 3 alpha Faddeev Equation for the Buck, Friedlich and Wheatly alpha alpha Potential

    CERN Document Server

    Fujiwara, Y; Kohno, M

    2004-01-01

    The 3 alpha orthogonality condition model using the Pauli-forbidden bound states of the Buck, Friedlich and Wheatly alpha alpha potential can yield a compact 3 alpha ground state with a large binding energy, in which a small admixture of the redundant components can never be eliminated.

  12. Semen quality and concentration of soluble proteins in the seminal plasma of Alpine bucks Semen quality and concentration of soluble proteins in the seminal plasma of Alpine bucks

    Directory of Open Access Journals (Sweden)

    Simone Eliza Facione Guimarães

    2010-06-01

    Full Text Available It was aimed to study the in vitro seminal quality analyzed by complementary tests and to compare them with physical, morphological and biochemical aspects of male goat semen of the Alpine breed. This experiment took place at the Federal University of Viçosa, situated at 20º45’ S latitude and 42º51’ W longitude, Southwest of Brazil. It was done during the summer months of January and February, and three adult male goats of the Alpine breed were used in intensive conditions. The semen was collected by artificial vagina method. In all semen samples (45 ejaculates, after the physical and morphological analysis, the hiposmotic test was done. In 24 ejaculates, it were done thermo-resistance test, and in 21 ejaculates it were determined the concentration of total soluble proteins in seminal plasma. The male goats presented difference in the semen physical and morphological aspects, in the hiposmotic test and thermo-resistance test, but they did not presented difference in total soluble proteins concentration in seminal plasma. Results of the slow thermo-resistance test and hiposmotic test were positively correlated (r = 0.60. It was concluded, according to our results, that the concentration of total soluble proteins in seminal plasma can not be used as a parameter to predict the seminal quality of Alpine bucks.It was aimed to study the in vitro seminal quality analyzed by complementary tests and to compare them with physical, morphological and biochemical aspects of male goat semen of the Alpine breed. This experiment took place at the Federal University of Viçosa, situated at 20º45’ S latitude and 42º51’ W longitude, Southwest of Brazil. It was done during the summer months of January and February, and three adult male goats of the Alpine breed were used in intensive conditions. The semen was collected by artificial vagina method. In all semen samples (45 ejaculates, after the physical and morphological analysis, the hiposmotic test

  13. Optimization of Inductance for Buck DC-DC Converter%Buck DC-DC变换器电感的优化设计

    Institute of Scientific and Technical Information of China (English)

    付园园; 姚素英; 徐江涛; 高静; 陈莞

    2012-01-01

    提出了一种优化电感的设计方法,以最小的电感实现了Buck DC-DC变换器最大输出纹波电压(MOVR)达到极小值.该方法首先通过计算得到连续导电模式(CCM)和不连续导电模式(DCM)下的输出纹波电压,然后根据电感取值分析这两种模式下的MOVR,最终得到了使MOVR达到极小值的最小电感.分析得到,对于任意给定的输入电压和负载范围,计算最大输入电压、最小负载下CCM和DCM模式的临界电感和最小输入电压、最大负载下的临界电感,则最优电感为两者中的较大值.Pspice仿真结果验证了上述理论分析的正确性,开关频率为52 kHz,输出电压12 V时,对于给定输入电压范围15~21V,负载范围35~170 Ω,最优电感为327μH.%In order to realize the lowest maximum output voltage ripple (MOVR) of Buck DC-DC converter with the minimal inductance, an optimal inductance design method is proposed. Output voltage, ripple (OVR) under continuous conduction mode (CCM) and discontinuous mode (DCM) was obtained by calculation, then MOVR in the two modes was analyzed according to the inductance value, and ultimately the minimum inductance to achieve the lowest MOVR was obtained. For any given range of the load and input voltage, by comparing the critical inductance between CCM and DCM under the maximum input voltage, minimum load condition and under the minimum input voltage, maximum load condition, it is concluded that the minimum inductance to guarantee the lowest MOVR is actually the maximum value of the critical inductance under the two conditions. The Pspice simulation results are in favor of the proposed theory.

  14. Conversor integrado SEPIC buck-boost aplicado ao acionamento de LEDs de potência em iluminação pública

    OpenAIRE

    Almeida, Pedro Santos

    2012-01-01

    Este trabalho apresenta um estudo acerca da alimentação de diodos emissores de luz (LEDs) a partir da rede elétrica empregando conversores eletrônicos com correção do fator de potência. O estudo visa o desenvolvimento de um conversor que pode ser aplicado em iluminação pública, que atenda às demandas típicas de alto fator de potência, alta eficiência, reduzido número de componentes, baixa distorção harmônica da corrente de entrada e possa atingir uma elevada vida útil, através ...

  15. Understanding USB-C Buck-Boost battery charging%解密USB-C升压-降压电池充电

    Institute of Scientific and Technical Information of China (English)

    魏佳

    2016-01-01

    本文分析了传统PC电源架构,描述了随着可反转USB Type-CTM线缆连接器的USB-C输电的广泛应用,PC电源架构将发生较大的变化。通过探讨不同的电池充电方法,解释了USB-C升压-降压充电拓扑如何才能提供设计工程师要求的灵活性、高效率和小解决方案尺寸。

  16. 浅议 PTA 料仓装车系统的设计%The Design of PTA Buck Silo & Truck Loading

    Institute of Scientific and Technical Information of China (English)

    彭荣杰

    2013-01-01

    The paper mainly introduced the design of PTA buck silo & truck loading .In order to better grasp the technology of PTA buck silo & truck loading, The principle of PTA buck silo & truck loading was analyzed and discussed.%  文章主要介绍了 PTA 料仓装车系统的的设计。通过对装车系统设计的一些设计原则进行了分析和探讨,以便于更好地掌握和改进PTA 料仓装车系统的技术。

  17. Boosting the accuracy of hedonic pricing models

    NARCIS (Netherlands)

    M.C. van Wezel (Michiel); M. Kagie (Martijn); R. Potharst (Rob)

    2005-01-01

    textabstractHedonic pricing models attempt to model a relationship between object attributes and the object's price. Traditional hedonic pricing models are often parametric models that suffer from misspecification. In this paper we create these models by means of boosted CART models. The method is

  18. Quadratic Boost A-Source Impedance Network

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; Blaabjerg, Frede; Chub, Andrii

    2016-01-01

    A novel quadratic boost type A-source impedance network is proposed in this paper for realizing converters that demand a very high voltage gain. To achieve that, the proposed network uses an auto-transformer, whose obtained gain is quadratically dependent on the duty ratio and is presently not ma...

  19. Quadratic Boost A-Source Impedance Network

    DEFF Research Database (Denmark)

    Siwakoti, Yam Prasad; Blaabjerg, Frede; Chub, Andrii

    2016-01-01

    A novel quadratic boost A-source impedance network is proposed to realize converters that demand very high voltage gain. To satisfy the requirement, the network uses an autotransformer where the obtained gain is quadratically dependent on the duty ratio and is unmatched by any existing impedance ...

  20. The Attentional Boost Effect and Context Memory

    Science.gov (United States)

    Mulligan, Neil W.; Smith, S. Adam; Spataro, Pietro

    2016-01-01

    Stimuli co-occurring with targets in a detection task are better remembered than stimuli co-occurring with distractors--the attentional boost effect (ABE). The ABE is of interest because it is an exception to the usual finding that divided attention during encoding impairs memory. The effect has been demonstrated in tests of item memory but it is…

  1. Niacin to Boost Your HDL "Good" Cholesterol

    Science.gov (United States)

    Niacin can boost 'good' cholesterol Niacin is a B vitamin that may raise your HDL ("good") cholesterol. But side effects might outweigh benefits for most ... been used to increase high-density lipoprotein (HDL) cholesterol — the "good" cholesterol that helps remove low-density ...

  2. Taxation Policies Adjust,Motor Vehicles Boost

    Institute of Scientific and Technical Information of China (English)

    Alice

    2007-01-01

    @@ In recent years,Chinese automotive industry,as one of the pillar industries has kept on rising.In 2006,Chinese auto production ranked the third in the world.The governmental authorities are also studying the corresponding taxations to boost the healthy development of Chinese automotive industry.

  3. Schools Enlisting Defense Industry to Boost STEM

    Science.gov (United States)

    Trotter, Andrew

    2008-01-01

    Defense contractors Northrop Grumman Corp. and Lockheed Martin Corp. are joining forces in an innovative partnership to develop high-tech simulations to boost STEM--or science, technology, engineering, and mathematics--education in the Baltimore County schools. The Baltimore County partnership includes the local operations of two major military…

  4. Mediterranean Diet Plus Olive Oil a Boost to Heart Health?

    Science.gov (United States)

    ... gov/news/fullstory_163557.html Mediterranean Diet Plus Olive Oil a Boost to Heart Health? It enhances protective ... HealthDay News) -- A Mediterranean diet high in virgin olive oil may boost the protective effects of "good" cholesterol, ...

  5. 438 Adaptive Kernel in Meshsize Boosting Algorithm in KDE (Pp ...

    African Journals Online (AJOL)

    FIRST LADY

    2011-01-18

    Jan 18, 2011 ... classifier is boosted by suitably re-weighting the data. This weight ... Methods. Algorithm on Boosting Kernel Density Estimates and Bias Reduction ... Gaussian (since all distributions tend to be normal as n, the sample size,.

  6. Best bang for your buck: GPU nodes for GROMACS biomolecular simulations.

    Science.gov (United States)

    Kutzner, Carsten; Páll, Szilárd; Fechner, Martin; Esztermann, Ansgar; de Groot, Bert L; Grubmüller, Helmut

    2015-10-05

    The molecular dynamics simulation package GROMACS runs efficiently on a wide variety of hardware from commodity workstations to high performance computing clusters. Hardware features are well-exploited with a combination of single instruction multiple data, multithreading, and message passing interface (MPI)-based single program multiple data/multiple program multiple data parallelism while graphics processing units (GPUs) can be used as accelerators to compute interactions off-loaded from the CPU. Here, we evaluate which hardware produces trajectories with GROMACS 4.6 or 5.0 in the most economical way. We have assembled and benchmarked compute nodes with various CPU/GPU combinations to identify optimal compositions in terms of raw trajectory production rate, performance-to-price ratio, energy efficiency, and several other criteria. Although hardware prices are naturally subject to trends and fluctuations, general tendencies are clearly visible. Adding any type of GPU significantly boosts a node's simulation performance. For inexpensive consumer-class GPUs this improvement equally reflects in the performance-to-price ratio. Although memory issues in consumer-class GPUs could pass unnoticed as these cards do not support error checking and correction memory, unreliable GPUs can be sorted out with memory checking tools. Apart from the obvious determinants for cost-efficiency like hardware expenses and raw performance, the energy consumption of a node is a major cost factor. Over the typical hardware lifetime until replacement of a few years, the costs for electrical power and cooling can become larger than the costs of the hardware itself. Taking that into account, nodes with a well-balanced ratio of CPU and consumer-class GPU resources produce the maximum amount of GROMACS trajectory over their lifetime.

  7. single-phase dc phase dc-ac boost converter ac boost converter ...

    African Journals Online (AJOL)

    User

    Change of load current flow is achieved with achieved ... increased efficiency and simpler controllers. 814698 .... Figure 2. Power circuit and controllers for the proposed boost inverter. ..... [13] R.D.Middlebrook and S. Cuk, ''A general unified.

  8. A Cost Constrained Boosting Algorithm for Fast Object Detection

    OpenAIRE

    Militzer, Arne; Tietjen, Christian; Hornegger, Joachim

    2013-01-01

    Boosting methods are among the most widely used machine learning techniques in practice for various reasons. In many scenarios, however, their use is prevented by runtime constraints. In this paper we propose a novel technique for reducing the computational complexity of hierarchical classifiers based on AdaBoost, such as the probabilistic boosting tree, which are often used for object detection. We modify AdaBoost training so that the hypothesis generation is no longer based solely on the...

  9. Análisis de la estabilidad de un convertidor buck multicelular de dos celdas

    Directory of Open Access Journals (Sweden)

    Julián Pelaéz

    2014-12-01

    Full Text Available En este trabajo se presenta un convertidor multicelular con dos células bajo un modo de modulación (PWM de control de voltaje por ancho de pulso. El convertidor buck multicelular obtenido puede ser utilizado como un circuito electrónico de potencia para aplicaciones de alta tensión; donde los dispositivos semiconductores tienen la capacidad de cambiar solo a niveles de bajo voltaje. El análisis de estabilidad se ha hecho para un control puramente proporcional y más tarde, se ha extendido para un control Proporcional-Integral (PI. Los resultados de la simulación demuestran la validez del análisis.

  10. H∞ LPV Control with Pole Placement Constraints for Synchronous Buck Converters with Piecewise-Constant Loads

    Directory of Open Access Journals (Sweden)

    Hwanyub Joo

    2015-01-01

    Full Text Available This paper addresses the output regulation problem of synchronous buck converters with piecewise-constant load fluctuations via linear parameter varying (LPV control scheme. To this end, an output-error state-space model is first derived in the form of LPV systems so that it can involve a mismatch error that temporally arises from the process of generating a feedforward control. Then, to attenuate the mismatch error in parallel with improving the transient behavior of the converter, this paper proposes an LMI-based stabilization condition capable of achieving both H∞ and pole-placement objectives. Finally, the simulation and experimental results are provided to show the validity of our approach.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  12. A current-mode buck DC-DC controller with adaptive on-time control

    Energy Technology Data Exchange (ETDEWEB)

    Li Yanming; Lai Xinquan; Ye Qiang; Yuan Bing; Chen Fuji [Institute of Electronic CAD, Xidian University, Xi' an 710071 (China); Jia Xinzhang, E-mail: ymli2004@126.co, E-mail: xqlai@mail.xidian.edu.c [Microelectronics Institute, Xidian University, Xi' an 710071 (China)

    2009-02-15

    A current-mode buck DC-DC controller based on adaptive on-time (AOT) control is presented. The on-time is obtained by the techniques of input feedforward and output feedback, and the adaptive control is achieved by a sample-hold and time-ahead circuit. The AOT current-mode control scheme not only obtains excellent transient response speed, but also achieves the independence of loop stability on output capacitor ESR. In addition, the AOT current-mode control does not have subharmonic oscillation phenomenon seen in fixed frequency peak current-mode control, so there is no need of the slope compensation circuit. The auto-skip pulse frequency modulation (PFM) mode improves the conversion efficiency of light load effectively. The controller has been fabricated with UMC 0.6-mum BCD process successfully and the detailed experimental results are shown.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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)

  14. Sliding mode controller with modified sliding function for DC-DC Buck Converter.

    Science.gov (United States)

    Naik, B B; Mehta, A J

    2017-09-01

    This article presents design of Sliding Mode Controller with proportional integral type sliding function for DC-DC Buck Converter for the controlled power supply. The converter with conventional sliding mode controller results in a steady state error in load voltage. The proposed modified sliding function improves the steady state and dynamic performance of the Convertor and facilitates better choices of controller tuning parameters. The conditions for existence of sliding modes for proposed control scheme are derived. The stability of the closed loop system with proposed sliding mode control is proved and improvement in steady state performance is exemplified. The idea of adaptive tuning for the proposed controller to compensate load variations is outlined. The comparative study of conventional and proposed control strategy is presented. The efficacy of the proposed strategy is endowed by the simulation and experimental results. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  15. Low-temperature operation of a Buck DC/DC converter

    Science.gov (United States)

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

    1995-01-01

    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.

  16. Quantization Effects on Period Doubling Route to Chaos in a ZAD-Controlled Buck Converter

    Directory of Open Access Journals (Sweden)

    John Alexander Taborda

    2012-01-01

    cycles. On the other hand many studies have been devoted to analyze the ZAD-controlled buck power converter, but these past studies did not include hardware considerations. In this paper, analog-to-digital conversion process is explicitly introduced in the modeling stage. As the feedback gain is varied, the dynamic behavior depending on the analog-to-digital converter resolution is numerically analyzed. Particularly, it is observed that including the quantizer in the model carries out several changes in the transitions to chaos, which include interruption of band-merging process by cascades of periodic inclusions, disappearing of band transitions, and multiple coexisting of periodic orbits. Many of these phenomena have not been reported as a consequence of the quantization effects.

  17. Comparative Performance Analysis of Sliding Mode and Q-Controller Algorithms for Buck Converter

    Science.gov (United States)

    Pati, Nivedita

    2017-08-01

    The switched mode dc-dc converters are some of the simplest power electronic circuits which have received an increasing deal of interest in many areas due to their high efficiency and small size. These converters are non-linear and time-variant in nature; hence the analysis, control and stabilization are the main factors that need to be considered. Many control methodology are used for control of switch mode dc-dc converters but the optimum one is always in demand. This paper presents the linearization of the Buck converter model and a comparison between a linear and non-linear control algorithms for better output voltage regulation along with robustness to change in input voltage and load parameters. The computer –aided design software tool Matlab/Simulink is used for the simulations and the results are presented.

  18. Optimal Control with Complete Load-Decoupled Design for the Buck DC-DC Switching Converter

    Institute of Scientific and Technical Information of China (English)

    Fei-Hu; Hsieh; Yau-Tarng; Juang

    2002-01-01

    This paper describes a new controller design procedure and turning method for the buck PWM DCDCswitching converter taking into consideration the equivalent series resistance of components. First, the linearoptimal feedback is designed by the LQR approach. Then the designed control law is implemented by aphase-lag lead controller incorporated with a complete load-decoupled PD compensator. The phase-lag lead controlleris tuned to achieve the optimal design based on the output error voltage directly, instead of using an estimator.With the proposed PD compensator, the converter is robust with respect to the load changes and parameterperturbations. We also provide the conditions for the robust stability assurance of the closed-loop system.

  19. Effect of Air Space in Storage Vials on Motility of Spermatozoa in Chilled Buck Semen

    Directory of Open Access Journals (Sweden)

    Magnus Paul K and Lali F Anand 1

    Full Text Available This study was conducted in order to find out the effect of air space on the top of glass vial in which semen is stored, on the motility of spermatozoa. 45 samples collected from two bucks over a span of 6 months were used for experiment. Goat milk extender was the diluent used. Two ml each of diluted semen after noting their initial motility was stored in 2 ml and 5 ml vials. Samples were stored at 5°C and motility of spermatozoa noted at 24 and 48 hours. Semen without air space was found to preserve the motility better than semen with air space on 24 and 48 hours of incubation. This could be better attributed to reactive oxygen species production by the spermatozoa, but further investigation is needed in this aspect to confirm it. [Veterinary World 2010; 3(9.000: 421-423

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

    Institute of Scientific and Technical Information of China (English)

    Lü Danzhu; Yu Jiale; Hong Zhiliang

    2013-01-01

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

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

    Science.gov (United States)

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

    2010-11-01

    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 μm 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%.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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%.

  3. Aquifer tests and simulation of ground-water flow in Triassic sedimentary rocks near Colmar, Bucks and Montgomery Counties, Pennsylvania

    Science.gov (United States)

    Risser, Dennis W.; Bird, Philip H.

    2003-01-01

    This report presents the results of a study by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency to evaluate ground-water flow in Triassic sedimentary rocks near Colmar, in Bucks and Montgomery Counties, Pa. The study was conducted to help the U.S. Environmental Protection Agency evaluate remediation alternatives at the North Penn Area 5 Superfund Site near Colmar, where ground water has been contaminated by volatile organic solvents (primarily trichloroethene). The investigation focused on determining the (1) drawdown caused by separately pumping North PennWater Authority wells NP?21 and NP?87, (2) probable paths of groundwater movement under present-day (2000) conditions (with NP?21 discontinued), and (3) areas contributing recharge to wells if pumping from wells NP-21 or NP?87 were restarted and new recovery wells were installed. Drawdown was calculated from water levels measured in observation wells during aquifer tests of NP?21 and NP?87. The direction of ground-water flow was estimated by use of a three-dimensional ground-water-flow model. Aquifer tests were conducted by pumping NP?21 for about 7 days at 257 gallons per minute in June 2000 and NP?87 for 3 days at 402 gallons per minute in May 2002. Drawdown was measured in 45 observation wells during the NP?21 test and 35 observation wells during the NP?87 test. Drawdown in observation wells ranged from 0 to 6.8 feet at the end of the NP?21 test and 0.5 to 12 feet at the end of the NP?87 test. The aquifer tests showed that ground-water levels declined mostly in observation wells that were completed in the geologic units penetrated by the pumped wells. Because the geologic units dip about 27 degrees to the northwest, shallow wells up dip to the southeast of the pumped well showed a good hydraulic connection to the geologic units stressed by pumping. Most observation wells down dip from the pumping well penetrated units higher in the stratigraphic section that were not well

  4. NOAA ESRI Geotiff- 1m Multibeam Bathymetry of St. Croix (Buck Island), US Virgin Islands, Project NF-05-05, 2005, UTM 20 NAD83 (NCEI Accession 0131860)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains an ESRI Geotiff with 1 meter cell size representing the bathymetry of the north shore of St. Croix (Buck Island), US Virgin Islands.NOAA's...

  5. NOAA ESRI Geotiff- 1m Multibeam Bathymetry of St. Croix (Buck Island), US Virgin Islands, Project NF-05-05, 2005, UTM 20 NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains an ESRI Geotiff with 1 meter cell size representing the bathymetry of the north shore of St. Croix (Buck Island), US Virgin Islands.NOAA's...

  6. NOAA TIFF Graphic- 0.5m Backscatter Mosaic of St. Croix (Buck Island), US Virgin Islands, 2005 (NCEI Accession 0131860)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 1 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands.NOAA's NOS/NCCOS/CCMA Biogeography Team...

  7. GeoTIFF of 3x3 m Bathymetry for Buck Island, St. Croix, 2011, UTM 20N NAD83 (NCEI Accession 0131858)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a LiDAR (Light Detection & Ranging) 3x3 meter resolution bathymetric surface for an area including and surrounding Buck Island Reef...

  8. GeoTIFF of 3x3 m Relative Reflectivity for Buck Island, St. Croix, 2011, UTM 20N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a LiDAR (Light Detection & Ranging) 3x3 meter resolution relative seafloor reflectivity surface for an area including and surrounding Buck...

  9. GeoTIFF of 3x3 m Relative Reflectivity for Buck Island, St. Croix, 2011, UTM 20N NAD83 (NCEI Accession 0131858)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a LiDAR (Light Detection & Ranging) 3x3 meter resolution relative seafloor reflectivity surface for an area including and surrounding Buck...

  10. NOAA ESRI Grid- 5m Multibeam Bathymetry of St. Croix (Buck Island), US Virgin Islands, Project NF-05-05, 2005, UTM 20 NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains an ESRI Grid with 5 meter cell size representing the bathymetry of the north shore of St. Croix (Buck Island), US Virgin Islands.NOAA's...

  11. NOS ESRI Grid, Unified 10m Multibeam Bathymetry La Parguera, Puerto Rico and Buck Island, St. Croix 2006: Project NF-06-03, UTM 20 NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified ESRI Grid with 10 meter cell size representing the bathymetry of selected portions of seafloor around La Parguera, P.R. and Buck...

  12. Dual Buck Hybrid Cascaded Multilevel Inverter%复合型级联多电平双buck式逆变器

    Institute of Scientific and Technical Information of China (English)

    嵇保健; 洪峰; 张广明

    2011-01-01

    采用不同级联单元构建的复合型结构成为级联多电平逆变器电路重要的研究与发展方向。为此,提出了一种新颖的复合型级联多电平双buck逆变器结构。该逆变器引入双buck电路作为基本组成单元,由双buck电路和桥式电路级联构成,发挥各自优点;并采用开环工频控制和滞环电流脉宽调制(PWM)控制相结合的控制方案。其中,双buck电路采用PWM控制,完成输出波形闭环控制,充分利用双buck电路无桥臂直通、无开关器件体二极管反向恢复、适宜高频化的特点;而桥式电路单元开关管在整个工频周期仅开关一次,输出阶梯合成波(三电平时为%A dual buck hybrid cascaded multilevel inverter is presented, and a novel dual buck circuit is introduced into this inverter as the basic cascaded cell. Then, the inverter is made of one dual buck cell and several bridge cells. The merits of dual buck circuit and bridge circuit are remained in this hybrid inverter. And a simple control method composed of low working-frequency switch control and hysteretic current pulse width modulate (PWM) control is adopted. This method is easy to be accomplished. The main cascaded part of the inverter which is modulated by hysteretic current PWM close-loop control method is the dual buck cell. Dual buck circuit is a highly efficient and reliable topology which overcomes the shoot-through problem in traditional bridge inverter, and its switches and diodes can be designed respectively. The other cascaded parts of inverter are all bridge cells, working in a working-frequency switch mode and providing main sector of output voltage. Low frequency and high voltage pressure components can be used as switches of bridge cell. This inverter remains the merits of cascaded multilevel inverter that the harmonic content of output voltage is low, so the filter can be simplified, and its reliability and efficiency are improved.

  13. Factorization for substructures of boosted Higgs jets

    Science.gov (United States)

    Isaacson, Joshua; Li, Hsiang-nan; Li, Zhao; Yuan, C.-P.

    2017-08-01

    We present a perturbative QCD factorization formula for substructures of an energetic Higgs jet, taking the energy profile resulting from the H → b b bar decay as an example. The formula is written as a convolution of a hard Higgs decay kernel with two b-quark jet functions and a soft function that links the colors of the two b quarks. We derive an analytical expression to approximate the energy profile within a boosted Higgs jet, which significantly differs from those of ordinary QCD jets. This formalism also extends to boosted W and Z bosons in their hadronic decay modes, allowing an easy and efficient discrimination of fat jets produced from different processes.

  14. QCD resummations for boosted top production

    CERN Document Server

    Ferroglia, Andrea; Scott, Darren J; Yang, Li Lin

    2015-01-01

    We present new results for QCD corrections to the top-pair invariant mass and top-quark $p_T$ distributions in boosted top-quark pair production at hadron colliders. They are derived from a formalism which allows the joint resummation of soft and small-mass logarithms at NNLL$'$ order, thus taking into account all potentially large corrections in the boosted regime, where the partonic center-of-mass energy is parameterically much larger than the mass of the top quark. We match these results with those from standard soft-gluon resummation away from the small-mass limit to NNLL order and also with NLO fixed-order calculations, so that our results are valid in the maximum possible range of phase space. The resummation effects on the $p_T$ and top-pair invariant mass distributions are significant, bringing theory predictions into better agreement with experimental data compared to pure NLO calculations.

  15. Scaling Turbo Boost to a 1000 cores

    CERN Document Server

    S, Ananth Narayan; Fedorova, Alexandra

    2010-01-01

    The Intel Core i7 processor code named Nehalem provides a feature named Turbo Boost which opportunistically varies the frequencies of the processor's cores. The frequency of a core is determined by core temperature, the number of active cores, the estimated power consumption, the estimated current consumption, and operating system frequency scaling requests. For a chip multi-processor(CMP) that has a small number of physical cores and a small set of performance states, deciding the Turbo Boost frequency to use on a given core might not be difficult. However, we do not know the complexity of this decision making process in the context of a large number of cores, scaling to the 100s, as predicted by researchers in the field.

  16. Non-boost-invariant dissipative hydrodynamics

    CERN Document Server

    Florkowski, Wojciech; Strickland, Michael; Tinti, Leonardo

    2016-01-01

    The one-dimensional non-boost-invariant evolution of the quark-gluon plasma, presumably produced during the early stages of heavy-ion collisions, is analyzed within the frameworks of viscous and anisotropic hydrodynamics. We neglect transverse dynamics and assume homogeneous conditions in the transverse plane but, differently from Bjorken expansion, we relax longitudinal boost invariance in order to study the rapidity dependence of various hydrodynamical observables. We compare the results obtained using several formulations of second-order viscous hydrodynamics with a recent approach to anisotropic hydrodynamics, which treats the large initial pressure anisotropy in a non-perturbative fashion. The results obtained with second-order viscous hydrodynamics depend on the particular choice of the second-order terms included, which suggests that the latter should be included in the most complete way. The results of anisotropic hydrodynamics and viscous hydrodynamics agree for the central hot part of the system, ho...

  17. Substructure of Highly Boosted Massive Jets

    Energy Technology Data Exchange (ETDEWEB)

    Alon, Raz [Weizmann Inst. of Science, Rehovot (Israel)

    2012-10-01

    Modern particle accelerators enable researchers to study new high energy frontiers which have never been explored before. This realm opens possibilities to further examine known fields such as Quantum Chromodynamics. In addition, it allows searching for new physics and setting new limits on the existence of such. This study examined the substructure of highly boosted massive jets measured by the CDF II detector. Events from 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron Collider were collected out of a total integrated luminosity of 5.95 fb$^{-1}$. They were selected to have at least one jet with transverse momentum above 400 GeV/c. The jet mass, angularity, and planar flow were measured and compared with predictions of perturbative Quantum Chromodynamics, and were found to be consistent with the theory. A search for boosted top quarks was conducted and resulted in an upper limit on the production cross section of such top quarks.

  18. Factorization for substructures of boosted Higgs jets

    CERN Document Server

    Isaacson, Joshua; Li, Zhao; Yuan, C -P

    2015-01-01

    We present a perturbative QCD factorization formula for substructures of an energetic Higgs jet, taking the energy profile resulting from the $H\\to b\\bar b$ decay as an example. The formula is written as a convolution of a hard Higgs decay kernel with two $b$-quark jet functions and a soft function that links the colors of the two $b$ quarks. We derive an analytical expression to approximate the energy profile within a boosted Higgs jet, which significantly differs from those of ordinary QCD jets. This formalism also extends to boosted $W$ and $Z$ bosons in their hadronic decay modes, allowing an easy and efficient discrimination of fat jets produced from different processes.

  19. Cash boost to Great British science unveiled

    CERN Multimedia

    2002-01-01

    "Trade and Industry Secretary, Patricia Hewitt today unveiled new plans for the DTI's record science budget over the next three years, to keep Britain at the forefront of world science. The plans include funding to develop life saving new health techniques, to seek alternative energy sources, to help our rural economy, to develop the computers of tomorrow and boost business with the next generation of leading edge technologies" (1 page).

  20. Tracking down hyper-boosted top quarks

    CERN Document Server

    Larkoski, Andrew J; Selvaggi, Michele

    2015-01-01

    The identification of hadronically decaying heavy states, such as vector bosons, the Higgs, or the top quark, produced with large transverse boosts has been and will continue to be a central focus of the jet physics program at the Large Hadron Collider (LHC). At a future hadron collider working at an order-of-magnitude larger energy than the LHC, these heavy states would be easily produced with transverse boosts of several TeV. At these energies, their decay products will be separated by angular scales comparable to individual calorimeter cells, making the current jet substructure identification techniques for hadronic decay modes not directly employable. In addition, at the high energy and luminosity projected at a future hadron collider, there will be numerous sources for contamination including initial- and final-state radiation, underlying event, or pile-up which must be mitigated. We propose a simple strategy to tag such "hyper-boosted" objects that defines jets with radii that scale inversely proportion...

  1. Boosted Dark Matter at Neutrino Experiments

    CERN Document Server

    Necib, Lina; Wongjirad, Taritree; Conrad, Janet M

    2016-01-01

    Current and future neutrino experiments can be used to discover dark matter, not only in searches for dark matter annihilating to neutrinos, but also in scenarios where dark matter itself scatters off Standard Model particles in the detector. In this work, we study the sensitivity of different neutrino detectors to a class of models called boosted dark matter, in which a subdominant component of a dark sector acquires a large Lorentz boost today through annihilation of a dominant component in a dark matter-dense region, such as the galactic center or dwarf spheroidal galaxies. This analysis focuses on the sensitivity of different neutrino detectors, specifically the Cherenkov-based Super-K and the future argon-based DUNE to boosted dark matter that scatters off electrons. We study the dependence of the expected limits on the experimental features, such as energy threshold, volume and exposure in the limit of constant scattering amplitude. We highlight experiment-specific features that enable current and futur...

  2. b-tagging in boosted topologies

    CERN Document Server

    CMS Collaboration

    2015-01-01

    As the LHC explores a new energy regime, searches for physics beyond the Standard Model at high mass scale will probe objects produced with a momentum considerably higher than their mass, modifying in a very appreciable way the event topology. The decay products of boosted objects will be collimated into a smaller area such that they could be merged within a single \\emph{fat} jet. Highly boosted objects represent a challenge to the standard jet algorithm, object identification and isolation criteria, developed for decaying particles approximately at rest in the laboratory frame. For larger boosts above order of $p_T>$200 GeV, the final state from the $H\\rightarrow b\\bar{b}$ or $t\\rightarrow bW$ decay can merge into a single jet and the approach to reconstruct the Higgs boson or top quark in this environment should change drastically. Rather than attempting to resolve jets individually, the decaying object is reconstructed as a single fat jet. Then, the composite nature of the jet is revealed by analyzing its ...

  3. Effects of bio-stimulation induced by the presence of buck on reproductive performance of rabbit does

    Directory of Open Access Journals (Sweden)

    M.L. Alicata

    2011-03-01

    Full Text Available Over the last few years, bio-stimulation methods have aroused interest as an alternative ways of employing exogenous gonadotropins to improve the sexual receptivity of lactating does and, consequently, the overall productivity of rabbit farms (Theau-Clement, 2000. Among the possible stimulation methods, the so called “buck effect” has been little investigated. The buck effect, understood as the visual, auditory, olfactory and tactile contact between female and male, following a period of separation from the male, is known to be effective in ewes and sows in stimulating and synchronizing oestrus. The existence of stimulus of an olfactory nature has also been established in rabbits. In fact, the pheromones secreted by the sebaceous glands in males have been shown to induce sexual maturity in young female rabbits (Frank, 1966. Moreover, in nulliparous rabbit does, the presence of males contributes to an increased acceptance to mating.......

  4. Fast-Scale and Slow-Scale Subharmonic Oscillation of Valley Current-Mode Controlled Buck Converter

    Institute of Scientific and Technical Information of China (English)

    ZHOU Guo-Hua; XU Jian-Ping; BAO Bo-Cheng; ZHANG Fei; LIU Xue-Shan

    2010-01-01

    @@ A valley current-mode (VCM) controlled buck converter with current source load (CSI) has complex phenomena of fast-scale and slow-scale subharmonic oscillations.The piecewise smooth switching model of the VCM controlled buck converter with CSI is established.It is found that attractive regions of fast-scale and slow-scale subharmonic oscillations exist in the bifurcation diagram,and two tori exist in the corresponding Poincaré mapping.The research results by time-domain simulation indicate that U-type subharmonic oscillation (SO) constituted by SO and frequency-reduced subharmonic oscillation (FSO) exists in inductor current,and sine-type SO constituted by fast scale and low scaie exists in output voltage respectively.Experimental results are given to verify the analysis and simulation results.

  5. Effect of cooling rate and equilibration time on pre-freeze and post-thaw survival of buck sperm.

    Science.gov (United States)

    Ahmad, Mushtaq; Nasrullah, Rashad; Ahmad, Nasim

    2015-06-01

    Survival of buck sperm is affected due to duration and temperature of stages of refrigerated or frozen storage. This study investigated interactive effect of cooling rates (moderate; MC and rapid cooling; RC); and equilibration times (0, 2, 4 and 8h) on survival before freezing at 4°C and post-thaw quality of buck sperm. Semen was collected (three Beetal bucks; replicates=6), pooled and diluted with Tris-citrate extender. Pooled semen samples were subjected to either RC (-2.2°C/min) or MC (-0.3°C/min) from 37°C to 4°C in separate aliquots and further equilibrated at 4°C for 8h. Semen was frozen using standard procedure after completion of each equilibration period i.e. 0, 2, 4 and 8h. Semen was evaluated for motility, viability, plasma membrane integrity (PMI) and normal apical ridge (NAR) before freezing and after thawing. The survival time (time for survival above threshold limit i.e. 60%) at 4°C, of motility and PMI was observed 5 and 6h respectively in RC group while >8h in MC group. Rate of decline (slope) in motility and viability was higher (Pbuck sperm is higher when cooled with moderate rate. However, RC can maintain post-thaw sperm viability and PMI equal to MC when equilibrated for 2-8h. The methods should be explored to maintain motility and NAR during rapid cooling of buck sperm. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Fast and robust object detection using asymmetric totally corrective boosting.

    Science.gov (United States)

    Wang, Peng; Shen, Chunhua; Barnes, Nick; Zheng, Hong

    2012-01-01

    Boosting-based object detection has received significant attention recently. In this paper, we propose totally corrective asymmetric boosting algorithms for real-time object detection. Our algorithms differ from Viola and Jones' detection framework in two ways. Firstly, our boosting algorithms explicitly optimize asymmetric loss of objectives, while AdaBoost used by Viola and Jones optimizes a symmetric loss. Secondly, by carefully deriving the Lagrange duals of the optimization problems, we design more efficient boosting in that the coefficients of the selected weak classifiers are updated in a totally corrective fashion, in contrast to the stagewise optimization commonly used by most boosting algorithms. Column generation is employed to solve the proposed optimization problems. Unlike conventional boosting, the proposed boosting algorithms are able to de-select those irrelevant weak classifiers in the ensemble while training a classification cascade. This results in improved detection performance as well as fewer weak classifiers in the learned strong classifier. Compared with AsymBoost of Viola and Jones, our proposed asymmetric boosting is nonheuristic and the training procedure is much simpler. Experiments on face and pedestrian detection demonstrate that our methods have superior detection performance than some of the state-of-the-art object detectors.

  7. One Clock-Cycle Response 0.5 m CMOS Dual-Mode ΣΔ DC-DC Bypass Boost Converter Stable over Wide ESRLC Variations

    Directory of Open Access Journals (Sweden)

    Neeraj A. Keskar

    2010-01-01

    Full Text Available Power supplies in portable applications must not only conform and adapt to their highly integrated on-chip and in-package environments but also, more intrinsically, respond quickly to fast load dumps to achieve and maintain high accuracy. The frequency-compensation network, however, limits speed and regulation performance because it must cater to all combinations of filter capacitor , inductor L, and 's equivalent series resistance ESR resulting from tolerance and modal design targets. As such, it must compensate the worst-case condition and therefore restrain the performance of all other possible scenarios, even if the likelihood of occurrence of the latter is considerably high and the former substantially low. Sigma-delta (ΣΔ control, which addresses this issue in buck converters by easing its compensation requirements and offering one-cycle transient response, has not been able to simultaneously achieve high bandwidth, high accuracy, and wide ESRLC compliance in boost converters. This paper presents a dual-mode ΣΔ boost bypass converter, which by using a high-bandwidth bypass path only during transient load-dump events was experimentally 1.41 to 6 times faster than the state of the art in current-mode ΣΔ boost supplies, and this without any compromise in ESRLC compliance range (0–50 mΩ, 1–30 H, and 1–350 F.

  8. Historical and Current U.S. Strategies for Boosting Distributed Generation (Chinese Translation)

    Energy Technology Data Exchange (ETDEWEB)

    Lowder, Travis [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schwabe, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhou, Ella [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arent, Douglas J. [Joint Inst. for Strategic Energy Analysis, Golden, CO (United States)

    2015-08-01

    This is the Chinese translation of NREL/TP-6A20-64843. This report seeks to introduce a variety of top-down and bottom-up practices that, in concert with the macro-environment of cost-reduction globally and early adoption in Europe, helped boost the distributed generation photovoltaic market in the United States. These experiences may serve as a reference in China's quest to promote distributed renewable energy.

  9. Quasi-Periodicity, Chaos and Coexistence in the Time Delay Controlled Two-Cell DC-DC Buck Converter

    Science.gov (United States)

    Koubaâ, Karama; Feki, Moez

    In addition to border collision bifurcation, the time delay controlled two-cell DC/DC buck converter is shown to exhibit a chaotic behavior as well. The time delay controller adds new design parameters to the system and therefore the variation of a parameter may lead to different types of bifurcation. In this work, we present a thorough analysis of different scenarios leading to bifurcation and chaos. We show that the time delay controlled two-cell DC/DC buck converter may also exhibit a Neimark-Sacker bifurcation which for some parameter set may lead to a 2D torus that may then break yielding a chaotic behavior. Besides, the saturation of the controller can also lead to the coexistence of a stable focus and a chaotic attractor. The results are presented using numerical simulation of a discrete map of the two-cell DC/DC buck converter obtained by expressing successive crossings of Poincaré section in terms of each other.

  10. Hierarchical Velocity Control Based on Differential Flatness for a DC/DC Buck Converter-DC Motor System

    Directory of Open Access Journals (Sweden)

    R. Silva-Ortigoza

    2014-01-01

    Full Text Available This paper presents a hierarchical controller that carries out the angular velocity trajectory tracking task for a DC motor driven by a DC/DC Buck converter. The high level control is related to the DC motor and the low level control is dedicated to the DC/DC Buck converter; both controls are designed via differential flatness. The high level control provides a desired voltage profile for the DC motor to achieve the tracking of a desired angular velocity trajectory. Then, a low level control is designed to ensure that the output voltage of the DC/DC Buck converter tracks the voltage profile imposed by the high level control. In order to experimentally verify the hierarchical controller performance, a DS1104 electronic board from dSPACE and Matlab-Simulink are used. The switched implementation of the hierarchical average controller is accomplished by means of pulse width modulation. Experimental results of the hierarchical controller for the velocity trajectory tracking task show good performance and robustness against the uncertainties associated with different system parameters.

  11. A Low Input Current and Wide Conversion Ratio Buck Regulator with 75% Efficiency for High-Voltage Triboelectric Nanogenerators

    Science.gov (United States)

    Luo, Li-Chuan; Bao, De-Chun; Yu, Wu-Qi; Zhang, Zhao-Hua; Ren, Tian-Ling

    2016-01-01

    It is meaningful to research the Triboelectric Nanogenerators (TENG), which can create electricity anywhere and anytime. There are many researches on the structures and materials of TENG to explain the phenomenon that the maximum voltage is stable and the current is increasing. The output voltage of the TENG is high about 180-400 V, and the output current is small about 39 μA, which the electronic devices directly integration of TENG with Li-ion batteries will result in huge energy loss due to the ultrahigh TENG impedance. A novel interface circuit with the high-voltage buck regulator for TENG is introduced firstly in this paper. The interface circuit can transfer the output signal of the TENG into the signal fit to a lithium ion battery. Through the circuit of the buck regulator, the average output voltage is about 4.0 V and the average output current is about 1.12 mA. Further, the reliability and availability for the lithium ion battery and the circuit are discussed. The interface circuit is simulated using the Cadence software and verified through PCB experiment. The buck regulator can achieve 75% efficiency for the High-Voltage TENG. This will lead to a research hot and industrialization applications.

  12. Identifier-based adaptive neural dynamic surface control for uncertain DC-DC buck converter system with input constraint

    Science.gov (United States)

    Chen, Qiang; Ren, Xuemei; Oliver, Jesus Angel

    2012-04-01

    In this paper, an identifier-based adaptive neural dynamic surface control (IANDSC) is proposed for the uncertain DC-DC buck converter system with input constraint. Based on the analysis of the effect of input constraint in the buck converter, the neural network compensator is employed to ensure the controller output within the permissible range. Subsequently, the constrained adaptive control scheme combined with the neural network compensator is developed for the buck converter with uncertain load current. In this scheme, a newly presented finite-time identifier is utilized to accelerate the parameter tuning process and to heighten the accuracy of parameter estimation. By utilizing the adaptive dynamic surface control (ADSC) technique, the problem of "explosion of complexity" inherently in the traditional adaptive backstepping design can be overcome. The proposed control law can guarantee the uniformly ultimate boundedness of all signals in the closed-loop system via Lyapunov synthesis. Numerical simulations are provided to illustrate the effectiveness of the proposed control method.

  13. Totally Corrective Multiclass Boosting with Binary Weak Learners

    CERN Document Server

    Hao, Zhihui; Barnes, Nick; Wang, Bo

    2010-01-01

    In this work, we propose a new optimization framework for multiclass boosting learning. In the literature, AdaBoost.MO and AdaBoost.ECC are the two successful multiclass boosting algorithms, which can use binary weak learners. We explicitly derive these two algorithms' Lagrange dual problems based on their regularized loss functions. We show that the Lagrange dual formulations enable us to design totally-corrective multiclass algorithms by using the primal-dual optimization technique. Experiments on benchmark data sets suggest that our multiclass boosting can achieve a comparable generalization capability with state-of-the-art, but the convergence speed is much faster than stage-wise gradient descent boosting. In other words, the new totally corrective algorithms can maximize the margin more aggressively.

  14. Nanophotonic boost of intermolecular energy transfer

    CERN Document Server

    de Roque, P M; Sapienza, R

    2015-01-01

    We propose a scheme for efficient long-range energy transfer between two distant light emitters separated by more than one wavelength of light, i.e. much beyond the classical Forster radius. A hybrid nanoantenna-waveguide system mediates the transmission of energy, showing enhancements up to 10^8 as compared to vacuum. Our model shows how energy transfer in nanostructured media can be boosted, beyond the simple donor Purcell enhancement, and in particular for large donor-acceptor separations. The scheme we propose connects realistic emitters and could lead to practical on-chip implementations.

  15. BOOSTING CED USING ROBUST ORIENTATION ESTIMATION

    Directory of Open Access Journals (Sweden)

    Tariq M. Khan

    2014-05-01

    Full Text Available In this paper, Coherence Enhancement Diffusion (CED is boosted feeding external orientation using new robust orientation estimation. In CED, proper scale selection is very important as the gradient vector at that scale reflects the orientation of local ridge. For this purpose a new scheme is proposed in which pre calculated orientation, by using local and integration scales. From the experiments it is found the proposed scheme is working much better in noisy environment as compared to the traditional Coherence Enhancement Diffusion

  16. Mixed Lorentz boosted $Z^{0}'s$

    CERN Document Server

    Kjaer, N J

    2001-01-01

    A novel technique is proposed to study systematic errors on jet reconstruction in W physics measurements at LEP2 with high statistical precision. The method is based on the emulation of W pair events using Mixed Lorentz Boosted Z0 events. The scope and merits of the method and its statistical accuracy are discussed in the context of the DELPHI W mass measurement in the fully hadronic channel. The numbers presented are preliminary in the sense that they do not constitute the final DELPHI systematic errors.

  17. Can role models boost entrepreneurial attitudes?

    Science.gov (United States)

    Fellnhofer, Katharina; Puumalainen, Kaisu

    2017-01-01

    This multi-country study used role models to boost perceptions of entrepreneurial feasibility and desirability. The results of a structural equation model based on a sample comprising 426 individuals who were primarily from Austria, Finland and Greece revealed a significant positive influence on perceived entrepreneurial desirability and feasibility. These findings support the argument for embedding entrepreneurial role models in entrepreneurship education courses to promote entrepreneurial activities. This direction is not only relevant for the academic community but also essential for nascent entrepreneurs, policymakers and society at large. PMID:28458611

  18. A Magnetohydrodynamic Boost for Relativistic Jets

    Science.gov (United States)

    Mizuno, Yosuke; Hardee, Philip; Hartmann, Dieter H.; Nishikawa, Ken-Ichi; Zhang, Bing

    2007-01-01

    We performed relativistic magnetohydrodynamic simulations of the hydrodynamic boosting mechanism for relativistic jets explored by Aloy & Rezzolla (2006) using the RAISHIN code. Simulation results show that the presence of a magnetic field changes the properties of the shock interface between the tenuous, overpressured jet (V^z j) flowing tangentially to a dense external medium. We find that magnetic fields can lead to more efficient acceleration of the jet, in comparison to the pure-hydrodynamic case. A "poloidal" magnetic field (B^z), tangent to the interface and parallel to the jet flow, produces both a stronger outward moving shock and a stronger inward moving rarefaction wave. This leads to a large velocity component normal to the interface in addition to acceleration tangent to the interface, and the jet is thus accelerated to larger Lorentz factors than those obtained in the pure-hydrodynamic case. Likewise, a strong "toroidal" magnetic field (B^y), tangent to the interface but perpendicular to the jet flow, also leads to stronger acceleration tangent to the shock interface relative to the pure-hydrodynamic case. Thus. the presence and relative orientation of a magnetic field in relativistic jets can significant modify the hydrodynamic boost mechanism studied by Aloy & Rezzolla (2006).

  19. Brain glucosamine boosts protective glucoprivic feeding.

    Science.gov (United States)

    Osundiji, Mayowa A; Zhou, Ligang; Shaw, Jill; Moore, Stephen P; Yueh, Chen-Yu; Sherwin, Robert; Heisler, Lora K; Evans, Mark L

    2010-04-01

    The risk of iatrogenic hypoglycemia is increased in diabetic patients who lose defensive glucoregulatory responses, including the important warning symptom of hunger. Protective hunger symptoms during hypoglycemia may be triggered by hypothalamic glucose-sensing neurons by monitoring changes downstream of glucose phosphorylation by the specialized glucose-sensing hexokinase, glucokinase (GK), during metabolism. Here we investigated the effects of intracerebroventricular (ICV) infusion of glucosamine (GSN), a GK inhibitor, on food intake at normoglycemia and protective feeding responses during glucoprivation and hypoglycemia in chronically catheterized rats. ICV infusion of either GSN or mannoheptulose, a structurally different GK inhibitor, dose-dependently stimulated feeding at normoglycemia. Consistent with an effect of GSN to inhibit competitively glucose metabolism, ICV coinfusion of d-glucose but not l-glucose abrogated the orexigenic effect of ICV GSN at normoglycemia. Importantly, ICV infusion of a low GSN dose (15 nmol/min) that was nonorexigenic at normoglycemia boosted feeding responses to glucoprivation in rats with impaired glucose counterregulation. ICV infusion of 15 nmol/min GSN also boosted feeding responses to threatened hypoglycemia in rats with defective glucose counterregulation. Altogether our findings suggest that GSN may be a potential therapeutic candidate for enhancing defensive hunger symptoms during hypoglycemia.

  20. Sliding mode control of reaction flywheel-based brushless DC motor with buck converter

    Institute of Scientific and Technical Information of China (English)

    Liu Gang; Zhang Cong

    2013-01-01

    Reaction flywheel is a significant actuator for satellites' attitude control.To improve out-put torque and rotational speed accuracy for reaction flywheel,this paper reviews the modeling and control approaches of DC-DC converters and presents an application of the variable structure system theory with associated sliding regimes.Firstly,the topology of reaction flywheel is constructed.The small signal linearization process for a buck converter is illustrated.Then,based on the state averaging models and reaching qualification expressed by the Lee derivative,the general results of the sliding mode control (SMC) are analyzed.The analytical equivalent control laws for reaction flywheel are deduced detailedly by selecting various sliding surfaces at electromotion,energy consumption braking,reverse connection braking stages.Finally,numerical and experimental examples are presented for illustrative purposes.The results demonstrate that favorable agreement is established between the simulations and experiments.The proposed control strategy achieves preferable rotational speed regulation,strong rejection of modest disturbances,and high-precision output torque and rotational speed tracking abilities.

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

    Science.gov (United States)

    Komurcugil, Hasan

    2012-11-01

    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.

  2. Bifurcation and chaos in high-frequency peak current mode Buck converter

    Science.gov (United States)

    Chang-Yuan, Chang; Xin, Zhao; Fan, Yang; Cheng-En, Wu

    2016-07-01

    Bifurcation and chaos in high-frequency peak current mode Buck converter working in continuous conduction mode (CCM) are studied in this paper. First of all, the two-dimensional discrete mapping model is established. Next, reference current at the period-doubling point and the border of inductor current are derived. Then, the bifurcation diagrams are drawn with the aid of MATLAB. Meanwhile, circuit simulations are executed with PSIM, and time domain waveforms as well as phase portraits in i L-v C plane are plotted with MATLAB on the basis of simulation data. After that, we construct the Jacobian matrix and analyze the stability of the system based on the roots of characteristic equations. Finally, the validity of theoretical analysis has been verified by circuit testing. The simulation and experimental results show that, with the increase of reference current I ref, the corresponding switching frequency f is approaching to low-frequency stage continuously when the period-doubling bifurcation happens, leading to the converter tending to be unstable. With the increase of f, the corresponding I ref decreases when the period-doubling bifurcation occurs, indicating the stable working range of the system becomes smaller. Project supported by the National Natural Science Foundation of China (Grant No. 61376029), the Fundamental Research Funds for the Central Universities, China, and the College Graduate Research and Innovation Program of Jiangsu Province, China (Grant No. SJLX15_0092).

  3. Ecology of juvenile hawksbills (Eretmochelys imbricata) at Buck Island Reef National Monument, US Virgin Islands

    Science.gov (United States)

    Hart, Kristen M.; Sartain-Iverson, Autumn R.; Hillis-Starr, Zandy; Phillips, Brendalee; Mayor, Philippe A.; Roberson, Kimberly; Pemberton, Roy A.; Allen, Jason B.; Lundgren, Ian; Musick, Susanna

    2013-01-01

    Surveys of juvenile hawksbills around Buck Island Reef National Monument, US Virgin Islands from 1994 to 1999 revealed distributional patterns and resulted in a total of 75 individual hawksbill captures from all years; turtles ranged from 23.2 to 77.7 cm curved carapace length (CCL; mean 42.1 ± 12.3 cm SD). Juveniles concentrated where Zoanthid cover was highest. Length of time between recaptures, or presumed minimum site residency, ranged from 59 to 1,396 days (mean 620.8 ± 402.4 days SD). Growth rates for 23 juveniles ranged from 0.0 to 9.5 cm year−1 (mean 4.1 ± 2.4 cm year−1SD). Annual mean growth rates were non-monotonic, with the largest mean growth rate occurring in the 30–39 cm CCL size class. Gastric lavages indicated that Zoanthids were the primary food source for hawksbills. These results contribute to our understanding of juvenile hawksbill ecology and serve as a baseline for future studies or inventories of hawksbills in the Caribbean.

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

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-12-01

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

  5. A miniature high-efficiency fully digital adaptive voltage scaling buck converter

    Science.gov (United States)

    Li, Hangbiao; Zhang, Bo; Luo, Ping; Zhen, Shaowei; Liao, Pengfei; He, Yajuan; Li, Zhaoji

    2015-09-01

    A miniature high-efficiency fully digital adaptive voltage scaling (AVS) buck converter is proposed in this paper. The pulse skip modulation with flexible duty cycle (FD-PSM) is used in the AVS controller, which simplifies the circuit architecture (<170 gates) and greatly saves the die area and the power consumption. The converter is implemented in a 0.13-μm one-poly-eight-metal (1P8 M) complementary metal oxide semiconductor process and the active on-chip area of the controller is only 0.003 mm2, which is much smaller. The measurement results show that when the operating frequency of the digital load scales dynamically from 25.6 MHz to 112.6 MHz, the supply voltage of which can be scaled adaptively from 0.84 V to 1.95 V. The controller dissipates only 17.2 μW, while the supply voltage of the load is 1 V and the operating frequency is 40 MHz.

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

    Science.gov (United States)

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

    2014-05-19

    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.

  7. The effect of supplementation on productive performance of Boer goat bucks fed winter veld hay.

    Science.gov (United States)

    Almeida, A M; Schwalbach, L M; de Waal, H O; Greyling, J P C; Cardoso, L A

    2006-07-01

    Fifteen Boer goat bucks, (6-8 months old), were allocated into two groups and fed ad libitum for a period of 29 days. The WH group (winter hay; n = 8) received a chopped diet consisting of grass hay, predominantly Themeda trianda grass (cut during the winter) from a natural pasture (veld). The WH+S group (winter hay plus supplement; n = 7) received a chopped diet consisting of Themeda trianda veld hay, supplemented with maize meal, molasses meal and urea. Body weights and feed consumption were recorded. Animals were slaughtered and carcass characteristics (weight and percentages of selected carcass cuts) and the carcass chemical composition were determined. The WH+S animals showed a higher live weight and cumulated feed intake. Carcass cuts from WH animals represented a higher percentage of the total carcass, especially cuts where muscle depots are higher (legs, best end chops and prime cuts). There is an attempt by non-supplemented animals to preserve the body's nitrogen reserves under prolonged nutritional stress conditions, and there is consequently a necessity to supplement feeding of small ruminants fed winter veld hay, especially if the animals are to be used in subsequent breeding seasons.

  8. Breast cancer regional radiation fields for supraclavicular and axillary lymph node treatment: is a posterior axillary boost field technique optimal?

    Science.gov (United States)

    Wang, Xiaochun; Yu, Tse Kuan; Salehpour, Mohammad; Zhang, Sean X; Sun, Tzouh Liang; Buchholz, Thomas A

    2009-05-01

    To assess whether using an anterior oblique supraclavicular (SCV) field with a posterior axillary boost (PAB) field is an optimal technique for targeting axillary (AX) lymph nodes compared with two computed tomography (CT)-based techniques: (1) an SCV field with an anterior boost field and (2) intensity-modulated radiotherapy (IMRT). Ten patients with CT simulation data treated with postmastectomy radiation that included an SCV field were selected for the study. Supraclavicular nodes and AX Level I-III nodes within the SCV field were contoured and defined as the treatment target. Plans using the three techniques were generated and evaluated for each patient. The anterior axillary boost field and IMRT resulted in superior dose coverage compared with PAB. Namely, treatment volumes that received 105%, 80%, and 30% of prescribed dose for IMRT plans were significantly less than those for the anterior axillary boost plans, which were significantly less than PAB. For PAB and anterior axillary boost plans, there was a linear correlation between treatment volume receiving 105% of prescribed dose and maximum target depth. Furthermore, the IMRT technique resulted in better lung sparing and dose conformity to the target than anterior axillary boost, which again was significantly better than PAB. The maximum cord dose for IMRT was small, but higher than for the other two techniques. More monitor units were required to deliver the IMRT plan than the PAB plan, which was more than the anterior axillary boost plan. The PAB technique is not optimal for treatment of AX lymph nodes in an SCV field. We conclude that CT treatment planning with dose optimization around delineated target volumes should become standard for radiation treatments of supraclavicular and AX lymph nodes.

  9. Transient excitation boosting at Grand Coulee third power plant: Power system application and field tests

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, C.W.; Mechenbier, J.R.; Matthews, C.E. (Bonneville Power Administration, Portland, OR (United States))

    1993-08-01

    Transient excitation boosting (TEB) has been installed on the Grand Coulee Third Power Plant hydrogenerators (three 600 MVA units and three 700 MVA units). TEB is initiated for outages of the 3100 MW Pacific HVDC Intertie, and results in a decaying pulse input to the generator voltage regulators. TEB temporarily raises Pacific Northwest transmission voltages which increases voltage-sensitive loads. The increased load brakes Northwest generators which are accelerating because of the loss of HVDC Intertie power. Transient stability of the parallel Pacific AC Intertie is thus improved. Power system-wide commissioning tests were conducted on May 7, 1991. The authors describe the tests and compare test results with simulation results.

  10. Maximum Power Point Tracking Controller for Thermoelectric Generators with Peak Gain Control of Boost DC-DC Converters

    Science.gov (United States)

    Park, Jungyong; Kim, Shiho

    2012-06-01

    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.

  11. Digital Implementation of Two Inductor Boost Converter Fed DC Drive

    Directory of Open Access Journals (Sweden)

    G. Kishor

    2011-01-01

    Full Text Available The study deals w ith simulation and implementation of two inductor boost converter fed DC drive. The two inductor boost converter fed DC drive is simulated and implemented. The circuit has advantages like higher output voltage and improved power factor. The laboratory model is implemented and the experimental results are obtained. The experimental results were compared w ith the simulation results.

  12. Boosted objects: a probe of beyond the standard model physics

    DEFF Research Database (Denmark)

    Abdesselam, A.; Belyaev, A.; Kuutmann, E. B.

    2011-01-01

    We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools...

  13. Boosted objects: a probe of beyond the standard model physics

    DEFF Research Database (Denmark)

    Abdesselam, A.; Belyaev, A.; Kuutmann, E. B.

    2011-01-01

    We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools ...

  14. A Single Switch Dual Output Non-Isolated Boost Converter

    DEFF Research Database (Denmark)

    Klimczak, Pawel; Munk-Nielsen, Stig

    2008-01-01

    very simple dual output non-isolated boost converter is presented. Single active switch is used to control both, positive and negative output voltages. The converter is desired to boost unregulated low input voltage 25-50 Vdc to regulated high voltage ±400 Vdc in dual dc-link. In this paper proposed...

  15. Application ofBoost Inverter to Multi Input PV system

    Directory of Open Access Journals (Sweden)

    G.SHINYVIKRAM

    2014-11-01

    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. The conventional boost converters increase the harmonics rate and add an extra stage of power conversion. This paper proposes a boost dc-ac inverter that can invert and boost the output voltage in a single stage. In this paper the proposed boost dc-ac inverter is applied to the solar power panels and is simulated using Simulink. The output results of the boost inverter are worthy promising.

  16. Very boosted Higgs in gluon fusion

    Energy Technology Data Exchange (ETDEWEB)

    Grojean, C. [Univ. Autonoma de Barcelona, Bellaterra (Spain). ICREA at IFAE; Salvioni, E. [California Univ., Davis, CA (United States). Dept. of Physics; European Organization for Nuclear Research (CERN), Geneva (Switzerland); Padova Univ. (Italy). Dipt. di Fisica e Astronomica; INFN, Sezione di Padova (Italy); Schlaffer, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Weiler, A. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-12-15

    The Higgs production and decay rates offer a new way to probe new physics beyond the Standard Model. While dynamics aiming at alleviating the hierarchy problem generically predict deviations in the Higgs rates, the current experimental analyses cannot resolve the long- and short-distance contributions to the gluon fusion process and thus cannot access directly the coupling between the Higgs and the top quark. We investigate the production of a boosted Higgs in association with a high-transverse momentum jet as an alternative to the t anti th channel to pin down this crucial coupling. Presented rst in the context of an effective field theory, our analysis is then applied to models of partial compositeness at the TeV scale and of natural supersymmetry.

  17. Boosting low-mass hadronic resonances

    Science.gov (United States)

    Shimmin, Chase; Whiteson, Daniel

    2016-09-01

    Searches for new hadronic resonances typically focus on high-mass spectra due to overwhelming QCD backgrounds and detector trigger rates. We present a study of searches for relatively low-mass hadronic resonances at the LHC in the case that the resonance is boosted by recoiling against a well-measured high-pT probe such as a muon, photon or jet. The hadronic decay of the resonance is then reconstructed either as a single large-radius jet or as a resolved pair of standard narrow-radius jets, balanced in transverse momentum to the probe. We show that the existing 2015 LHC data set of p p collisions with ∫L d t =4 fb-1 should already have powerful sensitivity to a generic Z' model which couples only to quarks, for Z' masses ranging from 20 - 500 GeV /c2 .

  18. Boosting jet power in black hole spacetimes.

    Science.gov (United States)

    Neilsen, David; Lehner, Luis; Palenzuela, Carlos; Hirschmann, Eric W; Liebling, Steven L; Motl, Patrick M; Garrett, Travis

    2011-08-02

    The extraction of rotational energy from a spinning black hole via the Blandford-Znajek mechanism has long been understood as an important component in models to explain energetic jets from compact astrophysical sources. Here we show more generally that the kinetic energy of the black hole, both rotational and translational, can be tapped, thereby producing even more luminous jets powered by the interaction of the black hole with its surrounding plasma. We study the resulting Poynting jet that arises from single boosted black holes and binary black hole systems. In the latter case, we find that increasing the orbital angular momenta of the system and/or the spins of the individual black holes results in an enhanced Poynting flux.

  19. Boosted W/Z Tagging at ATLAS

    CERN Document Server

    Dattagupta, Aparajita; The ATLAS collaboration

    2016-01-01

    A detailed study of the techniques for identifying boosted hadronically decaying W or Z bosons is presented. The best performing algorithm for reconstructing, grooming and tagging bosonic jets as seen in studies using 8 TeV data and simulation is validated for W bosons with a wide range of transverse momenta using 13 TeV data and MC simulations. The same is studied for Z bosons in 13 TeV MC simulation. Improvement in tagger performance using detector tracking information is also studied. In addition, given that a hadronic jet has been identified as resulting from the hadronic decay of a W or Z, a technique is developed to discriminate between W and Z bosons using 8 TeV data. The alternative of using variable-R jets for capturing the hadronic decay products compared to standard techniques is also discussed.

  20. Redundant visual signals boost saccade execution.

    Science.gov (United States)

    Turatto, Massimo; Betta, Elena

    2006-10-01

    The redundant signal effect (RSE) refers to the fact that human beings react more quickly to a pair of stimuli than to only one stimulus. In previous studies of the RSE in the oculomotor system, bimodal signals have been used as the goal of the saccade. In consistency with studies using manual response times (RTs), saccadic RTs have been shown to be shorter for redundant multimodal stimuli than for single unimodal stimuli. In the present experiments, we extended these findings by demonstrating an RSE in the saccadic system elicited only by unimodal visual stimuli. In addition, we found that shorter saccadic RTs were accompanied by an increased saccadic peak velocity. The present results are of relevance for neurophysiological models of saccade execution, since the boost of saccades was elicited by two visual transients (acting as a "go" signal) that were presented not at the goal of the saccade but at various other locations.