Design And Control Of Bidirectional DC To DC Converter For .
SEEE DIGIBOOK ON ENGINEERING & TECHNOLOGY, VOL. 01, MAY 2018ALTERNATE ENERGY TECHNOLOGIESDesign and Control ofBidirectional DC to DCConverter for Electric VehicleBattery ChargerS. Nishanthini, Dr. N. NarmadhaiGovernment College of Technology, Coimbatore, India.nishathini0695@gmail.com, narmadhai@gct.ac.inAbstract—The objective of this thesis is to monitor a battery integrated circuit by using a bi-directional DC-DC converter asthe channel for charging and discharging of the battery cell. The proposed converter provides a wide range output voltage forthe battery system and negligible harmonic content of the output current. In order to maintain a high efficiency undercharging, it adopts a bidirectional switch. In this topology, the non-isolated half bridge bidirectional DC-DC converter is used,allowing high flexibility for the charge and discharge of the battery and it has the advantage of lower inductor current andlower conduction as well as lower switching losses. It presents a battery charging and discharging in electric vehicleapplications to enhance the battery performance, low power loss, life cycle and safety. This project is started with the designof charging and discharging of a battery using LabVIEW. Thus, the overall system of a battery charger for a bidirectional DC-DCconverter can be an effective and thus it improves the efficiency of the converter and life cycle of the battery.Index Terms—charging and discharging, electric vehicle, battery performanceI. INTRODUCTIONAn integral part of any modern day electric vehicle is powerelectronic circuits (PECs) comprising of DC-AC inverters andDC-DC converters. A DC-AC inverter supplies the high powerelectric motor and utility loads such as air-conditioningsystem, whereas a DC-DC converter supplies conventionallow-power, low-voltage loads. However, the need for highpower bidirectional DC-DC converters in future electricvehicles has led to the development of many new topologiesof DC-DC converters.This paper presents an overview of DC-DC converters used inbattery electric vehicles (BEVs), hybrid electric vehicles(BEVs), and fuel cell vehicles (FCVs). Several DC-DC converterssuch as isolated, non-isolated, half-bridge, full-bridge,unidirectional and bidirectional topologies, and theirapplications in electric vehicles are presented. The proposedsystem mainly consists of non-isolated bi-directional dc-dcconverter of half-bridge topology.DC-DC converters in an electric vehicle may be classified intounidirectional and bidirectional converters. UnidirectionalDC-DC converters cater to various onboard loads such assensors, controls, entertainment, utility, and safetyequipment’s. They are also used in DC motor drives andelectric traction. Bidirectional DC-DC converters findapplications in places where battery charging, regenerativebraking, and backup power are required.The power flow in a bidirectional converter is usually from alow voltage end such as battery or a super capacitor to a highS. Nishanthini, nishathini0695@gmail.com;Dr. N. Narmadhai, narmadhai@gct.ac.in;voltage side and is referred to as boost operation. Duringregenerative braking, the power flows back to the lowvoltage bus to recharge the battery (buck mode). Due to theaforementioned reasons, high power bidirectional DC-DCconverters have gained a lot of importance in the recent past.The bidirectional dc-dc converter along with energy storagehas become a promising option for many power relatedsystems, including hybrid vehicle, fuel cell vehicle, renewableenergy system and so forth. It not only reduces the cost andimproves efficiency, but also improves the performance ofthe system.In renewable energy applications, the multiple-inputbidirectional dc-dc converter can be used to combinedifferent types of energy sources. This bidirectional dc-dcconverter features galvanic isolation between the load andthe fuel cell, bidirectional power flow capability; to matchdifferent voltage levels, fast response to the transient loaddemand, etc.II. PROPOSED BLOCK DIAGRAMA detailed model of proposed block diagram is shown infigure.2.147978-81-933187-0-6 2018 SEEEPEDIA.ORGSociety for Engineering Education Enrichment
SEEE DIGIBOOK ON ENGINEERING & TECHNOLOGY, VOL. 01, MAY 2018has to be achieved along with the power flow capability inboth the direction. A bidirectional DC-DC converter is neededto be able to allow power flow in both the directions at theregulated level. Basic DC-DC converters such as buck andboost converters do not have bidirectional power flowcapability. This limitation is due to the presence of diodes intheir structure which prevents reverse current flow. Ingeneral, a unidirectional dc-dc converter can be turned into abidirectional converter by replacing the diodes with acontrollable switch in its structure.Figure 1. Block diagram of proposed systemIII. BIDIRECTIONAL DC-DC CONVERTERIn most of charger systems for electric vehicles, bidirectionalconverters for charging and discharging the batteries arerequired. As compared to high-frequency transformerisolated bidirectional dc-dc converters, non-isolated bidirectional dc-dc converters generally have advantages ofsimple structure, high efficiency, low cost, high reliability, etc.One of the main concern while designing the electric vehiclebattery charging system is to maximize the efficiency of theload. This can be done by increasing the voltage level andthereby reducing the high current and thus the associatedlosses. Therefore a bidirectional dc-dc converter can bepreferred.Fig. 4. Power flow direction of converterBased on the placement of the auxiliary energy storage, thebidirectional dc-dc converter can be categorized into buckand boost type. The buck type is to have energy storageplaced on the high voltage side, and the boost type is to haveit placed on the low voltage side.To realize the double sided power flow in bidirectional dc-dcconverters, the switch cell should carry the current on bothdirections as shown in Fig. 5.A. Operation of ConverterHalf bridge non isolated bidirectional DC-DC converter isshown in Fig. 5. Low voltage battery pack is installed on bothside and on the other side. During step up switch Q1 isconducting at the required duty cycle while Q2 is remains inoff condition at all the time. Similarly during step downoperation Q2 is conductive at required Duty cycles whereasQ1 remains in off condition. In order to avoid crossconductance through two switches and converter outputcapacitance is controlled by providing small dead time duringtransitions mode.Fig. 1. Converter based batteryBidirectional DC–DC converters allow transfer of powerbetween two dc sources, in either direction. Due to theirability to reverse the direction of flow of current, and therebypower, while maintaining the voltage polarity at either endunchanged, they are being increasingly used in applicationslike dc uninterruptible power supplies, battery chargercircuits, telecom power supplies and computer powersystems.Fig. 5. Bidirectional DC-DC converterB. Continuous conduction modeA large valued filter inductor is required for continuousconduction mode of a bidirectional DC-DC converter. As theuse of large valued inductor, mode transitioning and transientresponse will goes on decreasing.Fig. 2. Electric vehicle battery charging systemBidirectional DC-DC converters serves the purpose ofstepping up or stepping down the voltage level between itsinput and output along with the capability of power flow inboth the directions as shown in Fig. 4. Bidirectional DC-DCconverters are employed when the DC bus voltage regulation148C. Discontinuous conduction modeIn this case, the inductor value is less as compare tocontinuous conduction mode so that the response becomesfaster this result in increasing power density. This operation978-81-933187-0-6 2018 SEEEPEDIA.ORGSociety for Engineering Education Enrichment
SEEE DIGIBOOK ON ENGINEERING & TECHNOLOGY, VOL. 01, MAY 2018allows zero turn on losses and thus low reverse recovery lossThe above circuit can be made to work in buck or boost modein diode.depending on the switching of the mosfets Q1 and Q2. Theswitches Q1 or Q2 in combination with the anti-parallelIV. NON ISOLATED BIDIRECTIONAL DC-DC CONVERTERdiodes D1 or D2 (acting as freewheeling diode) respectively,In the transformer-less non-isolated power conversionmakes the circuit step up or step down the voltage appliedsystems, the boost type and buck type dc-dc converter areacross them.chosen usually is shown in Fig. 6. The high frequencyB. Advantages of NBDC:transformer based system is an attractive one to obtain Structure is symmetrical.isolation between the source and load sides. But from the Low ripple current on both sideviewpoint of improving the efficiency, size, weight and cost, It has protection against short-circuit.the transformer-less type is much more attractive. Thus, inC. Limitations:the high power or spacecraft power system applications, It can only operate in buck mode in one directionwhere weight or size is the main concern, the transformerand boost in another mode.less type is more attractive in high power applications. Structure becomes impractical, when the voltageNon-isolated BDCs (NBDC) are simpler than isolated BDCsratio more.(IBDC) and can achieve better efficiency the transformer-less Galvanic isolation is less between two sides.type is more attractive in high power applications. For thepresent high power density bidirectional dc-dc converter, toincrease its power density, multiphase current interleavingtechnology with minimized inductance has been found inhigh power applications.A. Operation Of ConverterIn the transformer-less non-isolated power conversionsystems, the boost type and buck type dc-dc converter arechosen usually. The high frequency transformer based systemis an attractive one to obtain isolation between the sourceand load sides. But from the viewpoint of improving theefficiency, size, weight and cost, the transformer-less type ismuch more attractive. Thus, in the high power or spacecraftpower system applications, where weight or size is the mainconcern, the transformer-less type is more attractive in highpower applications.Non-isolated BDCs (NBDC) are simpler than isolated BDCs(IBDC) and can achieve better efficiency the transformer-lesstype is more attractive in high power applications. For thepresent high power density bidirectional dc-dc converter, toincrease its power density, multiphase current interleavingtechnology with minimized inductance has been found inhigh power applications.V. SIMULATION AND RESULTSThe performance evaluation of this model is based on the cosimulation LabVIEW/Multisim. With the intention ofdetermining the impact of the charging process on batteries,the behavior of different internal parameters of the batteriesand bidirectional dc-dc converter was simulated.The bidirectional dc-dc converter provides the channel ofcurrent flow during charging or discharging process. Thereare two switches used in this modes, which are charging anddischarging.A. Charging EvaluationIn the charging mode, the converter processes theequalization by transferring the required charge from batterystring to the detected undercharged cell.B. Discharging EvaluationIn the discharging mode operation of bidirectional dc-dcconverter, the step-up converter performs the equalizationby transferring the excess energy from the detectedovercharged cell to the battery string.VI. BATTERY MODEL SIMULATION STRUCTUREThe National Instruments Community presents the principleof co-simulation using the two simulators LabVIEW andMultisim. Therefore, the battery modelling and simulationare developed in the following manner. Firstly, the stagecircuitry is designed in Multisim which contains three parts:an equivalent circuit model, a charge or discharge mode.A. Multisim StageFig. 6. Non Isolated Half-Bridge Bidirectional DC-DC Converterresulting out of the antiparallel connection of the Buck andBoost convertersWhen the Buck and the boost converters are connected inantiparallel across each other with the resulting circuit isbasically having the same structure as the fundamental Boostand Buck structure but with the added feature ofbidirectional power flow. The above Fig. 6. shows the basicstructure of the Non-Isolated Half-Bridge Bidirectional DC-DCconverter.Fig. 7. Circuit diagram using MultisimThe equivalent circuit shown in Fig. 7. is composed of avoltage controlled source V1 in series with a voltagecontrolled resistor R1. The values of V1 and R1 depend on the149978-81-933187-0-6 2018 SEEEPEDIA.ORGSociety for Engineering Education Enrichment
SEEE DIGIBOOK ON ENGINEERING & TECHNOLOGY, VOL. 01, MAY 2018battery operation mode at a given time. The resistance alsoa)Low Current Waveformvaried with the sensed current.The charge and discharge mode switches offers the possibilityto switch between two modes according to the sent value bymean of the terminal Sw1. But at discharging time theconnection is switched to the voltage controlled resistor (R2)instead.B. LabVIEW StageFig. 10. Low current waveformThe Fig. 10. shows the low current output waveform of thebidirectional dc-dc converter during charging time of thebattery.b)Low Voltage WaveformFig. 8. Circuit diagram using LabVIEWFig. 11. Low voltage waveformIt represents the proposed LabVIEW to simulate theinstantaneous battery model parameters evolution. It cantest the impact of the current rate on batteries charging ordischarging process.During the charging mode the GUI gives the possibility todefine directly the value of the current, but during thedischarging mode, this value is defined by varying the loadresistance value. Moreover, the behavior of each battery canbe simulated at any given initial conditions.1)The Fig. 11. shows the low voltage output waveform of thebidirectional dc-dc converter during charging time of thebattery. In this mode, a buck converter can be switched onand it can be charged up to 12 V to 24 V.2)Pulse for Boost ConverterA boost converter (step-up converter) is a DC-to-DC powerconverter that steps up voltage (while stepping downcurrent) from its input (supply) to its output (load). Toreduce voltage ripple, filters made of capacitors (sometimesin combination with inductors) are normally added to such aconverter's output (load-side filter) and input (supply-sidefilter).Pulse for Buck ConverterFig. 9. Pulse for buck converterThe Fig. 9. shows that the pulse waveform for the buckconverter. Normally a buck converter (step-down converter)is a DC-to-DC power converter which steps down voltage(while stepping up current) from its input (supply) to itsoutput (load).Fig. 12. Pulse for boost converterThe Fig. 12. shows that the pulse waveform for the boostconverter.150978-81-933187-0-6 2018 SEEEPEDIA.ORGSociety for Engineering Education Enrichment
SEEE DIGIBOOK ON ENGINEERING & TECHNOLOGY, VOL. 01, MAY 2018a) High Current Waveformbased battery charger to cop traditional charger fails. Thiscontrol is taking the variation of temperature and SOC asinput to adjust the charging current as an output.AcknowledgmentThe authors are thankful to the authorities of Governmentcollege of Technology, Coimbatore for the facilities renderedto carry out this research work.Fig. 13. High current waveformREFERENCES[1]. M. A. Hannan, M. M. Hoque, A. Mohamed, and A. Ayob,“Review of energy storage systems for electric vehicleapplications: Issues and challenges,” Renewable andSustainable Energy Reviews, vol. 69, pp. 771–789, Mar.2017.[2]. M. M. Hoque, M. A. Hannan, and A. Mohamed, “VoltageEqualization Control Algorithm for Monitoring andBalancing of Series Connected Lithium-Ion Battery,” J.Renewable Sustainable Energy, vol. 8, no. 025703, pp. 115, Mar. 2016.[3]. Xianzhi Gong, Rui Xiong and Chunting Chris Mi, “A attery Modelling Approach for Electric VehicleApplications,” IEEE Trans. Ind. Appl., vol. 52, no. 2, pp.1759-1765, Mar./Apr. 2016.[4]. Il-Oun Lee, “Hybrid PWM-Resonant Converter for ElectricVehicle On-Board Battery Chargers,” IEEE Trans. PowerElectron., vol. 31, no. 5, pp. 3639 – 3649, May 2016.[5]. M. A. Hannan, M. M. Hoque, S. E. Peng, M. N, Uddin,“Lithium-ion battery charge equalization algorithm forelectric vehicle applications,” IEEE Industry ApplicationsSociety Annual Meeting, pp. 1-8, May 2016.[6]. Gong, R. Xiong, and C. C. Mi, “Study of the characteristicsof battery packs in electric vehicles with parallelconnected lithium-ion battery cells,” IEEE Trans. Ind.Appl., vol. 51, no. 2, pp. 1872–1879, Mar./Apr. 2015.[7]. David Anseán, Manuela González, Víctor M. Garcia, JuanC. Viera, Juan C. Antón, and Cecilio Blanco, “Evaluation ofLiFePO4 Batteries for Electric Vehicle Applications,” IEEETrans. Ind. Appl., vol. 51, no. 2, pp. 1855-1863, Mar./Apr.2015.[8]. Masatoshi Uno, and Akio Kukita, “Bidirectional PWMConverter Integrating Cell Voltage Equalizer Using SeriesResonant Voltage Multiplier for Series-Connected EnergyStorage Cells,” IEEE Trans. Power Electron., vol. 30, no. 6,pp. 3077-3090, Jun. 2015.[9]. Kyung-Min Lee, Yoo-Chae Chung, Chang-Hyeon Sung, andBongkoo Kang, “Active Cell Balancing of Li-Ion BatteriesUsing LC Series Resonant Circuit,” IEEE Trans. Ind.Electron., vol. 62, no. 9, pp. 5491–5501, Sep. 2015.[10]. Tasuku Anno, and Hirotaka Koizumi, “Double-InputBidirectional DC/DC Converter Using Cell-VoltageEqualizer With Flyback Transformer” IEEE Trans. PowerElectron., vol. 30, no. 6, pp. 2923-2934, Jun. 2015.[11]. Xiaosong Hu, Jiuchun Jiang, Bo Egardt, and Dongpu Cao,“Advanced Power-Source Integration in Hybrid ElectricVehicles: Multicriteria Optimization Approach,” IEEEThe Fig. 13. shows the high current output waveform of thebidirectional dc-dc converter during charging time of thebattery.b) High Voltage WaveformFig. 14. High voltage waveformThe Fig. 14. shows the high voltage output waveform of thebidirectional dc-dc converter during charging time of thebattery. In this mode, a buck converter can be switched onand it can be charged up to 24 V to 48 V.Thus the waveforms of the input and output voltages, andthe charging current during charge mode are presented.To make a full use of those batteries and to improve theirlifecycle, high performance charger is often required. Theimplementation of an advanced charger needs accurateinformation on the batteries internal parameters. During thecharging mode, the value of the current must decrease.VI. CONCLUSIONThis paper concerns with analysis, design and realization ofbidirectional dc-dc converter. This converter can be operatedin all three possible ways; it can be buck, boost and buckboost simply by selecting different combinations of theswitches for the EV system. The implementation of the modelwas based on the co-simulation LabVIEW-Multisim. Thecircuitry stage is designed in Multisim and the code ofcontrolling of this circuitry is developed in LabVIEW.This co-simulation is able to provide accurate simulationresults and a very fast simulation speed. Thereby, it revealsthe strong instantaneous relationship between the internalbatteries parameters and the charging current rate. The useof zero bidirectional dc-dc converter makes the systemoperation more efficient.The two simulators characteristically exchange data in asynchronized and variable time step mode. Simulation resultsdemonstrate the impact of the charging current on theinternal resistance and the capacitance of the battery. In thefuture work, it may be intend to implement a fuzzy-control-151978-81-933187-0-6 2018 SEEEPEDIA.ORGSociety for Engineering Education Enrichment
SEEE DIGIBOOK ON ENGINEERING & TECHNOLOGY, VOL. 01, MAY 2018Trans. Ind. Electron, vol. 62, no. 12, pp. 7847-7858, Dec.connected energy storage cells,” IEEE Trans. Veh.2015.Technol., vol. 60, no. 8, pp. 3635–3645, Oct. 2011.[12]. Nagaraj, B., and P. Vijayakumar. "Soft Computing Based[15]. Yuang-Shung Lee, and Ming-Wang Cheng, “IntelligentPID Controller Tuning and Application to the Pulp andControl Battery Equalization for Series ConnectedPaper Industry." Sensors & Transducers 133.10 (2011):Lithium-Ion Battery Strings,” IEEE Trans Ind. Electron.,30.vol. 52, no. 5, pp. 1297-1307, Oct. 2005.[13]. Moon-Young Kim, Chol-Ho Kim, Jun-Ho Kim and Gun[16]. Nagaraj, B., and P. Vijayakumar. "CONTROLLER TUNINGWoo Moon, “A Chain Structure of Switched Capacitor forFOR INDUSTRIAL PROCESS-A SOFT COMPUTINGImproved Cell Balancing Speed of Lithium-Ion Batteries,”APPROACH." Int. J. Advance. Soft Comput. Appl 4.2IEEE Trans. Ind. Electron., vol. 61, no. 8, pp. 3989-3999,(2012).Aug. 2014.[17]. M. Tang, T. Stuart, “Selective buck-boost equalizer for[14]. M. Uno and K. Tanaka, “Single-switch cell voltageseries battery packs,” IEEE Trans. Aeros. Electron.equalizer using multistacked buck–boost convertersSystems, vol. 36, no. 1, pp. 201–211, Jan. 2000.operating in discontinuous conduction mode for series-152978-81-933187-0-6 2018 SEEEPEDIA.ORGSociety for Engineering Education Enrichment
electric motor and utility loads such as air-conditioning system, whereas a DC-DC converter supplies conventional low-power, lowvoltage loads. However, the need for high - power bidirectional DC-DC converters in future electric vehicles has led to the development of
Series 765 – Bidirectional Slurry Valve 7 Series 766 – Bidirectional Slurry Valve 8 Series 767 – Bidirectional Slurry Valve 8 Series 768 – Bidirectional Slurry Valve 9 Series 770 – Bidirectional O-Port Gate Valve 9 Series
English-Myanmar Bidirectional Machine Translation System Proceedings of Fifth TheIIER-SCIENCE PLUS International Conference, Singapore, 08th November 2014, ISBN: 978-93-84209-62-9 91 IV. ENGLISH-MYANMAR BIDIRECTIONAL TRANSLATION SYSTEM Fig. 1. System Architecture In this paper, English-Myanmar Bidirectional Translation System is implemented.
8 Bidirectional DC-DC Converters for Energy Storage Systems Hamid R. Karshenas 1,2, Hamid Daneshpajooh 2, Alireza Safaee 2, Praveen Jain 2 and Alireza Bakhshai 2 1Department of Elec. & Computer Eng., Queen s University, Kingston, 2Isfahan University of Tech., Isfahan, 1Canada 2Iran 1. Introduction Bidirectional dc-dc converters (
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Bidirectional DC-DC Power Converter Design Optimization, Modeling and Control Junhong Zhang ABSTRACT In order to increase the p
This paper presents the design and construction of a digital bidirectional visitor counter (DBVC). The DBVC is a reliable circuit that takes over the task of counting number of persons / visitors in the room very accurately and beeps a warning alarm when the number of visitors exceeds the capacity limit of the auditorium/hall. When
bidirectional hard and soft limit switch inputs and bidirectional jog inputs are provided for each axis. These features are generally required in most machine control designs. 6 testable TTL, CMOS and 24V compatible inputs and 8
Korean language learning demotivation among EFL instructors in South Korea 201 competing commitments to language learning necessitating a cost/benefit anal-ysis of the time and cost versus the perceived return on such an investment (Norton, 2013), particularly, as negative gatekeeping encounters may result in marginalization (Norton, 2000, 2001). Thus, while the notion that in a globalized .
