Advanced Inter Grated Bidirectional ACDC and DCDC

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3970 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 58, NO. 8, OCTOBER 2009

Advanced Integrated Bidirectional AC/DCand DC/DC Converter for Plug-In

Hybrid Electric VehiclesYoung-Joo Lee, Student Member, IEEE, Alireza Khaligh, Member, IEEE, and Ali Emadi, Senior Member, IEEE

AbstractHybrid electric vehicle (HEV) technology provides aneffective solution for achieving higher fuel economy, better perfor-mance, and lower emissions, compared with conventional vehicles.Plug-in HEVs (PHEVs) are HEVs with plug-in capabilities andprovide a more all-electric range; hence, PHEVs improve fueleconomy and reduce emissions even more. PHEVs have a batterypack of high energy density and can run solely on electric powerfor a given range. The battery pack can be recharged by a neigh-borhood outlet. In this paper, a novel integrated bidirectional ac/dccharger and dc/dc converter (henceforth, the integrated converter)for PHEVs and hybrid/plug-in-hybrid conversions is proposed.The integrated converter is able to function as an ac/dc batterycharger and to transfer electrical energy between the batterypack and the high-voltage bus of the electric traction system. Itis shown that the integrated converter has a reduced number ofhigh-current inductors and current transducers and has providedfault-current tolerance in PHEV conversion.

Index TermsAC/DC rectifiers, control, dc/dc converters, elec-tric traction, energy storage, hybrid electric vehicles (HEVs),plug-in HEVs (PHEVs), power electronics, propulsion systems.

I. INTRODUCTION

C ONVERSION of conventional hybrid electric vehicles(HEVs) [1][3] into plug-in HEVs [4], [5] to reduce fuelconsumption [2] has been considered by both academia and theautomotive industry [6]. The conversion is achieved by either

adding a high-energy battery pack or replacing the existing

battery pack of HEV to extend the all-electric range [5]. In

either case, the high-energy battery pack should be charged

from an external ac outlet, as well as regenerative braking, and

must supply the stored electrical energy to the electric traction

system.

AC outlet charging inevitably needs a battery charger [7]

[11] with power factor correction (PFC) [8], [12], which

has various configurations based on an ac/dc converter and

Manuscript received November 17, 2008; revised May 12, 2009. Firstpublished July 21, 2009; current version published October 2, 2009. This workwas supported by the National Science Foundation under Grant 0801860. Thereview of this paper was coordinated by Prof. A. Miraoui.

Y.-J. Lee is with the R&E Center of Whirlpool Corporation, Benton Harbor,MI 49022 USA.

A. Khaligh is with the Energy Harvesting and Renewable Energies Labo-ratory, Electric Power and Power Electronics Center, Department of Electricaland Computer Engineering, Illinois Institute of Technology, Chicago, IL 60616-3793 USA (e-mail: [email protected]).

A. Emadi is with the Department of Electrical and Computer Engineering,Illinois Institute of Technology, Chicago, IL 60616-3793 USA.

Color versions of one or more of the figures in this paper are available onlineat http://ieeexplore.ieee.org.

Digital Object Identifier 10.1109/TVT.2009.2028070

a proper voltage-current profile for the high-energy battery

pack. The bidirectional dc/dc converter with a proper charging

discharging profile is required to transfer energy between the

battery and the electric traction system.

In this paper, PHEV conversion is based on the add-on high-

energy battery, which can leave the current HEV power system

unmodified, and battery voltage is supposed to be relatively

lower than the high-voltage bus of an electric traction system. It

is assumed that cost, volume, weight, and the number of currenttransducers and high-current inductors would be increased if

the ac/dc and bidirectional dc/dc converters were cascaded in

PHEVs. The converter for PHEV conversion should minimize

the electrical impact on the existing HEV power system, par-

ticularly from the point of view of fault current. The converter

has three operating modes, i.e., plug-in ac/dc charging of the

add-on battery, boost operation from the low-voltage add-on

battery to the high-voltage bus of the HEV, and buck operation

from the high-voltage bus to the add-on battery for regenerative

charging. It is essential to fairly satisfy the aforementioned

considerations. The purpose of this paper is to present the

integrated configuration and to demonstrate its feasibility forPHEV conversion.

This paper has been organized as follows: The concept of

PHEV conversion and the constitution of the proposed inte-

grated converter are shown in Section II. Section III explains

three operating modes of the proposed converter. In Section IV,

the expected change in loss and efficiency for feasibility estima-

tion is addressed by the comparison of the proposed converter

and conventional topologies. Section V presents the simulation

and experimental results to evaluate the proposed converter.

Finally, Section VI provides concluding remarks and future

work.

II. PLU G-I N HYBRID ELECTRIC VEHICLE CONVERSION

AN D PROPOSED INTEGRATED CONVERTER

A. PHEV Conversion

Fig. 1 shows an overall configuration of the PHEV conver-

sion. The main elements for the conversion comprise an ac/dc

charger, a high-energy battery added to the HEV, a bidirectional

dc/dc converter, and a digital controller with digital signal

processing (DSP). These main elements are in cascade, except

the digital controller, as seen. The plug-in charger is composed

of two parts: 1) ac/dc rectifier and 2) dc/dc converter (Conv. 1).

The bidirectional dc/dc converter (Conv. 2) is placed between

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LEE et al.: ADVANCED INTEGRATED BIDIRECTIONAL AC/DC AND DC/DC CONVERTER FOR PHEVs 3971

Fig. 1. PHEV conversion with the add-on battery.

the add-on battery and the high-voltage bus of the HEV. The

digital controller is in charge of the control and monitoring [13],

[14] of the ac/dc charger and bidirectional dc/dc converter, bat-

tery state of charge [15], and communication with external sys-tems. Three voltage sources, i.e., ac outlet voltage Vac, batteryvoltage Vbatt, and the high-voltage bus of HEV Vhv, are shownin Fig. 1. These voltages might be different in input/output

voltage magnitude in each converter. As an illustration, Conv. 1

with PFC should be in buck-and-boost operation when the peak

value ofVac (Vac_pk) is higher than Vbatt; otherwise, it shouldonly be in boost operation. The same rule is applied to Conv. 2

with Vbatt for input and Vhv for output.Basically, the three operations do not occur at the same time

in that plug-in charging is not allowed while the vehicle runs,

and discharging and regenerative charging of the battery are

exclusive to each other.

B. Proposed Converter

The proposed converter with controller is shown in Fig. 2

based on the operating conditions previously mentioned, which

does not have a cascaded structure, as shown in Fig. 1. The pro-

posed converter has one inductor, six switches, and five diodes,

which are going to be properly combined to select buck-and-

boost modes among voltage sources. There exist one current

feedback and three voltage feedbacks. The combinations of

switches and other components are mapped in Table I accord-

ing to the desired operating modes. Q1, Q2, and Q6 are for

pulsewidth modulation (PWM) switching of buck-and-boost

operations. Q3, Q4, and Q5 serve as simple on/off switches to

connect or disconnect the corresponding current flowing path.

III. OPERATING MODES OF THE INTEGRATED CONVERTER

A. Mode 1: Noninverting BuckBoost Operation for Plug-In

Charging of the Add-On Battery

Fig. 3 shows the instantaneous ac input voltage and operating

modes in Mode 1. In Fig. 3(b), Q1, Q2, Q3, D1, D3, and

L1 make up the noninverting buckboost converter [16][22],

which can provide a plug-in charger function with PFC without

regard to whether battery voltage Vbatt is higher than the peak

value of the ac outlet Vac_pk. Q1 and Q2 are in PWM switchingmode, and Q3 remains in the ON state during the operation.

Fig. 2. Proposed integrated converter with controller.

The desired output voltage and current are regulated by the

appropriate combinations of the buck-and-boost mode. The

input/output voltage and inductor current are measured through

Rs1, Rs2, Rs3, Rs4, and CT1. The other switches and diodes

Q4, Q5, Q6, D4, D5, and D6 stay in the OFF state to disconnect

the high-voltage bus of the HEV from both the ac input and the

add-on battery.

B. Mode 2: Boost Operation From the Add-On Battery to the

High-Voltage Bus of the HEV

Boost operation from the add-on battery to the high-voltagebus of the HEV is shown in Fig. 4. In this mode, Vbatt andVhv sequentially become input and output voltages. L1, Q2, Q4,Q5, D4, and D5 form a boost converter in that a Vhv higherthan Vbatt is assumed. Q2 is in PWM switching mode, andQ4 and Q5 are in the ON state, so that the current path can

appear between the battery and the high-voltage bus. The other

switches and diodes Q1, Q3, Q6, D1, D3, and D6 maintain the

OFF state to separate the ac outlet. The input/output voltage and

inductor current are measured through Rs3, Rs4, Rs5, Rs6, and

CT1. Power from the battery to the high-voltage bus can be

estimated using the measured battery voltage and current so

that transferable power at a certain state of charge should beregulated appropriately.

C. Mode 3: Buck Operation for Regenerative Charging of the

Add-On Battery

Fig. 5 shows regenerative charging of the add-on battery

using buck operation from the high-voltage bus to the battery.

In this mode, as seen, L1, Q3, Q6, D1, D3, and D6 are used for

the buck converter now that a Vhv higher than Vbatt is assumed.Q6 works for PWM switching, Q3 stays in the ON state, and

D1 provides a free-wheeling path. Other switches and diodes

Q1, Q2, Q4, Q5, D4, and D5 are in the OFF state. To sense the

input/output voltage and current, Rs3, Rs4, Rs5, Rs6, and CT1are used.


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TABLE ICOMBINATIONS OF ELEMENTS FOR THE OPERATING MODES

Fig. 3. Mode 1: Plug-in charging of the add-on battery. (a) Instantaneous acinput voltage and operating modes. (b) Buck operation. (c) Boost operation.

Fig. 4. Mode 2: Boost from the add-on battery to the high-voltage bus.

D. Analytical Modeling of the Converter

As shown in Figs. 35, all operations of the converter aremade of buck-and-boost operations with different configura-

Fig. 5. Mode 3: Regenerative charging of the add-on battery.

tions of input/output voltages, as described in Table I. A sim-

plified converter model is shown in Fig. 6(a), which has nonin-

verting buck-boost topology. Based on the simplified model, the

state-space averaged large-signal transfer functions are derived,

as given by

Vo(s) =1LC

VinDbuck

s2

+1

RCs +1

LC

(large-signal model) (1)

Vo(0) = VinDbuck (large-signal dc gain) (2)

Vo(s) =1LC

Vin(1 Dboost)

s2 + 1RC

s + 1LC

(1 Dboost)2(large-signal model)

(3)

Vo(0) =Vin

1 Dboost(large-signal dc gain) (4)

and the state-space block diagram is shown in Fig. 6(b). The

state-space block diagram and resultant large-signal dc gain in

Figs. 6(b)(c) also provide very insightful physical information

that is of use to controller designers.In buck operation, the large-signal transfer functions and dc

gains are given by (1) and (2), respectively.

In boost operation, the large-signal transfer functions and dc

gains are given by (3) and (4), respectively.

IV. COMPARATIVE ANALYSIS

A comparison of the proposed and a conventional converter

is presented and summarized through criteria based on the

battery voltage range; fault current tolerance; voltage polarity;

and the number of switches (Q), diodes (D), current transducers

(CT), and high-current inductors (L) in Fig. 7 and Table II,respectively.


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Fig. 6. Simplified converter model, state-space block diagram, and large-signal dc gain. (a) Simplified model. (b) State-space block diagram of thesimplified model. (c) Resultant large-signal dc gain.

A. Component Point of View

Through the integrated structure, it becomes possible to

reduce the number of high-current inductors and current trans-

ducers. On the other side, more switches and diodes are added

to make up selective current paths among voltage sources Vac,Vbatt, and Vhv. In general, the high-current inductor has arelatively larger size and is heavier than other power elec-

tronic components, such as metaloxidesemiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors

(IGBTs), transistors, and diodes.

B. Voltage Polarity, Current Noise, and Switching Stress

Considering only the number of switches and diodes, adop-

tion of a bidirectional buckboost converter, as in Fig. 7(b),

seems to be a good choice. The buckboost converter, however,

has inverted output voltage, making it difficult to share common

ground and higher intrinsic diode reverse recovery current.

In addition, switching stress is higher than buck or boost

converters. Inverted output voltage and intrinsic higher current

noise must seriously be taken into consideration for high-powerapplications.

C. Fault Current Tolerance

As shown in Figs. 35, the fact that all the current paths,

including switches, pass an inductor helps reduce sharp fault

currents. However, in Fig. 7(a)(f), there exists such probable

fault current or high-reverse-recovery current path as the broken

lines in case of using either noninverting or inverting bidirec-

tional buckboost converters between voltage sources.

D. Available Battery Voltage Range

In the aspect of flexibility in the applicable ac grid voltage

and battery voltage, and the available output of the high-voltage

bus, the proposed converter can provide a wide range of inputs

and outputs in both a charger and bidirectional converter by

using noninverting buckboost topology, which has the same

steady-state output transfer function as that of conventional

buck-and-boost converters.

E. Change in Conduction Loss

It has been found that the proposed converter has relatively

slightly more conduction loss in all operating modes. The extra

conduction loss arises from additional switches and diodes for

fault-tolerance current paths. Thus, it is needed to estimate

and discuss the feasibility of the increase in conduction losses,

despite the advantages previously enumerated.

F. Estimation of Change in Conduction Losses

Changes in losses are classified into Modes 1, 2, and 3,

because these three modes are exclusive of each other all the

time. To make the criteria of comparison clear, the comparedconverters should have noninverting and relatively wider output

voltage for both the add-on battery and the high-voltage bus.

For such reasons, Fig. 7(a) was compared with the proposed

converter in each operating mode. The conduction losses of

diodes and switches can be calculated as

PD = VF IF[in watts] (diode conduction loss) (5)

PQ = VCE(SAT) ICE[in watts] (IGBT conduction loss)

(6)

PQ = RDS I2D[in watts] (MOSFET conduction loss) (7)

Pin =Po

old [in watts] [input power of Fig. 6(a)] . (8)

For Mode 1 (plug-in charging of the add-on battery), it is

found that the proposed converter has one more switch, as

shown in Fig. 3(a) and (b), compared with Fig. 7(a). In addition,

the increase in loss is

Pl = PQ3[in watts]. (9)

For Mode 2 (boost function from the add-on battery to the

high-voltage bus of the HEV), as shown in Fig. 4, one more

pair of diode and switch is added in the proposed converter,

compared with Fig. 7(a). The variation in loss is

Pl = PD4 + PQ5[in watts]. (10)


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Fig. 7. Comparison of the combinations of conventional converters. (a) Full bridge and two noninverting buck/boost. (b) Full bridge and two buck/boost.(c) PWM rectifier and noninverting buck/boost. (d) PWM rectifier and buck/boost. (e) Full bridge, boost, and noninverting buck/boost. (f) Full bridge, boost, andbuck/boost.

TABLE IISUMMARY OF THE PROPOSED AND THE CONVENTIONAL CONVERTER

For Mode 3 (regenerative charging of the add-on battery),

one more pair of diode and switch is placed, as shown in Fig. 5,

compared with Fig. 7(a). The change in loss is

Pl = PD6 + PQ3[in watts]. (11)

To estimate comparative change in efficiency, it is identified

that Po is the output power, Pin is the previous input power, oldis the previous efficiency, and new is the new efficiency. Oncechange in losses occurs, the variation in efficiency is given as

= new old. The comparative change in efficiency forall three modes is formulated as a function of old, Pl, andPo, i.e.,

= new old =

Po

Pin + Pl

Po

Pin

=1

PinPo

+ PlPo

PoPin

=1

1old

+ PlPo

old%. (12)

If the diodes in series with switches Q4, Q5, and Q6, which

only enhance the reliability of switches, are removed, then the

losses in diodes can be neglected. Table II and (12) can be a

basis to estimate the feasibility of the proposed converter. The

parameters for feasibility estimation are shown in Table III,

where the available neighborhood outlet power is set to 1.44 kW

[23]. The high-energy battery pack is assumed to be a series of

12 modules consisting of nominal 3.7-V Li-ion cells in 4S5P.

Assuming continuous conduction mode and a low ripplecurrent through the inductor with maximum output power Po,


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TABLE IIICONDITIONS FOR FEASIBILITY ESTIMATION

TABLE IVCHANGES IN LOSS AND EFFICIENCY

approximately additional conduction loss Pl and maximum

change in efficiency max are approximately calculated andsummarized as in Table IV. Loss calculation according to eachoperating mode is given as follows:

For Mode 1, in Fig. 3(a), assuming buckboost operation for

the worst loss calculation

Po_max = 1440 W = Vo_min Io_max

Io_max =1440

134= 10.75 A.

For MOSFETs

Pl = PQ3 = I2o_max RDS = 5.20 W

max = 11old

+ 5.201440

old = 0.254 0.322%.

For IGBTs

Pl = PQ3 = Io_max VCE(SAT) = 26.86 W

max =1

1old

+ 26.861440 old = 1.176 1.486%.

For Mode 2, in Fig. 4

Po_max= 5000 W =Vhv_min Ihv_max=Vbatt_min Ibatt_max

Ihv_max= 5000216

= 23.15 A, Ibatt_max=5000134

= 37.31 A.

For MOSFETs

Pl = PD4 + PQ4

= VF Ibatt_max + I2hv_max RDS = 59.52 W

max =1

1old +

59.525000

old = 0.754 0.954%.

For IGBTs

Pl = PD4 + PQ4

= VF Ibatt_max + VCE(SAT) Ihv_max = 93.28 W

max =1

1old

+ 93.285000

old = 1.176 1.486%.

In Mode 3, in Fig. 5

Po_max =5000 W = Vbatt_min Ibatt_max

Ibatt_max =5000

134= 37.31 A Vbatt_min = d Vhv_min

d =Vbatt_minVhv_min

=134

216= 0.620 d = 1 d = 0.38

Ihv_max = Ibatt_max d = 14.179 A.

For MOSFETs

Pl = PD6 + PQ3

= VF Ihvt_max + I2batt_max RDS = 76.11 W

max = 11old

+ 76.115000

old = 0.962 1.216%.

For IGBTs

Pl = PD6 + PQ3= VF Ihv_max + VCE(SAT) Ibatt_max

=106.75 W

max=1

1old

+ 106.755000

old=1.343 1.697%.

Table IV shows that maximum changes in efficiency maxusing MOSFETs and IGBTs are less than 1.3% and 1.7%,

respectively, under the given conditions.

V. SIMULATION AND EXPERIMENTAL RESULTS

To evaluate the proposed converter, simulations have been

performed, and the results are as in Figs. 810 using the

IGBT switches. The simulation conditions are provided in

Table V.

In Fig. 8, from the top, rectified ac input voltage |Vac|, theoutput voltage (battery voltage: Vbatt), current command forcurrent modulation Iref, control voltage command for PWMgeneration Vctrl, inductor current feedback IL_fbk, and ac line

current Iac are sequentially displayed. Mode-1 operation hasbeen simulated under two conditions where the peak value


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Fig. 8. Mode 1: Noninverting buckboost operation for plug-in charging. (a) Steady state during Vbatt < Vac_pk. (b) Steady state during Vo > Vac_pk.(c) Transient state during Vo > Vac_pk.

of the ac input voltage (Vac_pk) is lower than battery voltageVbatt, and Vac_pk is higher than Vbatt. Fig. 8(a) and (b) showsthat Vac_pk < Vbatt and that Vac_pk > Vbatt, respectively. Inaddition, the transient state is shown in Fig. 8(c). As seen, at

steady state under given conditions, it is found that the converter

works stably.

The steady states of Mode-2 operation (boost from the add-

on battery to the high-voltage bus of the electric drive train


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Fig. 9. Mode 2: Boost operation from the add-on battery to the high-voltage bus of the HEV. (a) Steady state for Vbatt = 134 V and Vhv = 216 V. (b) Steadystate for Vbatt = 202 V and Vhv = 330 V.

Fig. 10. Mode 3: Buck operation for regenerative charging of the add-onbattery.

system) have been simulated as in Fig. 9. Vbatt and Vhv (high-

voltage bus) are the input and output voltages, respectively.Waveforms are presented in the same manner as in Fig. 8,

TABLE VSIMULATION CONDITIONS

showing the boost operation of the converter to be stable withVbatt = 134 V/Vhv= 216 V and Vbatt = 202 V/Vhv= 330 V.Fig. 10 provides Mode 3 (buck from the high-voltage bus

to the add-on pack). Now, Vhv becomes the input voltage,and Vbatt is the output voltage of the converter. To simulatethe regenerative voltage when the vehicle is decelerated, Vhvhas been assumed to be sinusoidal with a half-period. Buck

operation starts as Vhv becomes higher than Vbatt, and buckoperation ends when Vhv decreases to Vbatt. Plots are alsoplaced in the same order as in Figs. 8 and 9. It is seen that the

control voltage command Vctrl for PWM generation properlygets shaped as Vhv varies.

In Fig. 11, the experimental setup is presented, which has

a controller based on TMS320F2812 DSP from Texas Instru-ments, the converter, and the self-designed isolated gate drivers


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Fig. 11. Experimental setup. (a) Block diagram. (b) Control flowchart forDSP. (c) Prototype converter.

and feedback interface circuits. The waveforms from the exper-

imental setup are shown in Fig. 12 according to the operating

modes. All the feedback signals from Vac, Vbatt, Vhv, and iLare isolated from the high-voltage part of the converter, asshown in Fig. 2. For experimental convenience, the maximum

Fig. 12. Waveforms according to the operating modes. (a) Waveforms ofMode 1 during Vbatt < Vac_pk. (b) Waveforms of Mode 2: Boost operation.(c) Waveforms of Mode 3: Buck operation.

output power of each operating mode has been scaled down to

100 W. In addition, the experimental conditions are shown in

Table VI.

Fig. 11(a) shows a block diagram of the experimental setupconsisting of the integrated converter, feedback interface and


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TABLE VIEXPERIMENTAL CONDITIONS

gate drivers, DSP controller board, and IBM PC for program

debugging. The control flowchart for the DSP controller is

shown in Fig. 11(b), in which 0 dctrl < 2 for Mode 1,1 dctrl < 2 for Mode 2, and 0 dctrl < 1 for Mode 3 areselectively chosen according to the operating modes, where

dctrl is calculated by Vctrl/Vmod, as in Fig. 2. A single controlroutine and control gains are used for all three modes. Fig. 11(c)

shows an experimental prototype.

Fig. 12(a) shows waveforms from Mode-1 operation. From

the top, ac input voltage Vac, output voltage Vbatt, currentcommand Iref, control voltage command for PWM genera-tion Vctrl, inductor current feedback IL_fbk, ac line current,buck switch PWM signal (G1), and boost switch PWM signal

(G2) at steady state are plotted in the same order as that inFig. 8. As shown, buck-and-boost operation is alternatively

carried out by the resultant control voltage command according

to the input-voltage/output-voltage relationship. The ac line

current is found to be modulated with the current command,

in spite of harmonics due to the performance of the current

controller.

Fig. 12(b) shows waveforms from Mode-2 operation. The

input voltage (battery voltage: Vbatt), output voltage (high-voltage bus: Vhv), and inductor current feedback IL_fbk arepresented from the top. Output voltage Vhv is set to 40 V. Ascan be expected, at steady state, the inductor current always

flows as far as the input voltage is lower than the output voltage,

as shown in Fig. 9. It is shown that the prototype converter

works stable at steady state, although the input voltage with

5-V/60-Hz ripple (12.5% ripple) has arbitrarily been givenfrom the power supply.

Fig. 12(c) shows the input voltage (high-voltage bus: Vhv),output voltage (battery voltage: Vbatt), and inductor currentfeedback(IL_fbk). As shown in Fig. 10, buck operation appearsduring the time that input voltage Vhv is greater than outputvoltage Vbatt. Forty volts is set as an output voltage, and theinput voltage provided by power supply varies from 35 to

70 V. The output voltage is found to be stable at steady

state. In addition, a longer current overshoot at the beginning

of each buck operation than the simulation result in Fig. 10is seen.

VI. CONCLUSION

An integrated ac/dc charger and bidirectional dc/dc converter

for PHEV applications has been presented in this paper. The

proposed integrated converter has been compared with existing

topologies, and its advantages have been pointed out. Variations

in conduction loss and efficiency due to the additional diodes

and switches have been addressed. Through the simulationand experimental prototype, the functionalities for the three

operating modes, i.e., the combination of buck and boost for

plug-in charging of the add-on battery, boost for discharging the

add-on battery, and buck for regenerative charging of the add-

on battery, have been verified. A power-management strategy

has been implemented using TI8 DSP 320F2812. The controller

chooses the control strategy and proper operating modes ac-

cording to input/output-voltagecurrent conditions.

To verify the practicality of the proposed converter for PHEV

applications, an onboard testing prototype and vehicle power-

management system need to be implemented in a real vehicle,

and fault tolerance of the system should be tested in real-worldapplications.

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[14] A. Khaligh, A. M. Rahimi, Y. J. Lee, C. Jian, A. Emadi, S. D. Andrews,

C. Robinson, and C. Finnerty, Digital control of an isolated active hybridfuel cell/Li-ion battery power supply, IEEE Trans. Veh. Technol., vol. 56,no. 6, pp. 37093721, Nov. 2007.


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Young-Joo Lee (S07) received the B.S. degreein electrical engineering from Korea University ofTechnology and Education, Cheon-An, Korea, in1996, the M.S. degree from Gwang-Woon Univer-sity, Seoul, Korea, in 2003, and the Ph.D. degree,focusing on the integrated bidirectional converter forplug-in hybrid electric vehicles, from the IllinoisInstitute of Technology, Chicago, in 2009.

In 1995, he joined SunStar R&C, Incheon, Korea,which is highly specialized in industrial sewing ma-chines, motors, and their controllers. Then, he joined

Genoray Co., Ltd., which manufactures X-ray fluoroscopy equipment formedical surgery. He is currently conducting research and development relatedto sensorless motor drives for appliances as a Lead Engineer with the R&ECenter of Whirlpool Corporation, Benton Harbor, MI. He has more than tenyears of experience in industries associated with industrial sewing machines,medical X-ray fluoroscopy, and appliances. His experiences cover control overbrushless direct current (BLDC), permanent magnet synchronous machine(PMSM), induction, stepper motors, power converters, X-ray electron tubes,and other electricpneumatic actuators.

Alireza Khaligh (S04M06) received the B.S. andM.S. degrees (with highest distinction) from SharifUniversity of Technology, Tehran, Iran, and thePh.D. degree from Illinois Institute of Technology(IIT), Chicago, all in electrical engineering.

He was a Postdoctoral Research Associate withthe Department of Electrical and Computer Engi-neering, University of Illinois, Urbana. He is cur-

rently an Assistant Professor and the Director of theEnergy Harvesting and Renewable Energies Labo-ratory, Electric Power and Power Electronics Cen-

ter, Department of Electrical and Computer Engineering, IIT, where he hasestablished courses and curriculum in the area of energy harvesting andrenewable-energy sources. He is the author/coauthor of more than 55 journaland conference proceeding papers, as well as three books, including Energy

Harvesting: Solar, Wind, and Ocean Energy Conversion Systems (CRC, 2009), Energy Sources, Elsevier Power Electronics Handbook (Elsevier, 2009), and Integrated Power Electronics Converters and Digital Control (CRC, 2009).His research interests include the modeling, analysis, design, and control ofpower electronic converters, hybrid electric and plug-in hybrid electric vehicles,energy scavenging/harvesting from environmental sources, and the design ofenergy-efficient power supplies for battery-powered portable applications.

Dr. Khaligh is a Member of the Vehicle Power and Propulsion Committee,the IEEE Vehicular Technology Society, the IEEE Power Electronics Society,the IEEE Industrial Electronics Society, the IEEE Education Society, and the

Society of Automotive Engineers. He is the Conference Chair of the IEEEChicago Section. He is also an Associate Editor for the IEEE TRANSACTIONSON VEHICULAR TECHNOLOGY (TVT) and was a Guest editor for the SpecialIssue of the IEEE TVT on Vehicular Energy Storage Systems. He was alsoa Guest editor for the Special Section on Energy Harvesting of the IEEETRANSACTIONS ON INDUSTRIAL ELECTRONICS. He was the recipient ofthe Distinguished Undergraduate Student Award from Sharif University ofTechnology, which was jointly presented by the Minister of Science, Research,and Technology and by the President of Sharif University, and the 2009 ArmourCollege of Engineering Excellence in Teaching Award from IIT.

Ali Emadi (S98M00SM03) received the B.S.and M.S. degrees (with highest distinction) in elec-trical engineering from Sharif University of Technol-ogy, Tehran, Iran, and the Ph.D. degree in electrical

engineering from Texas A&M University, CollegeStation.

He is currentlythe HarrisPerlstein Endowed ChairProfessor of Electrical Engineering and the Directorof the Electric Power and Power Electronics Centerand Grainger Laboratories, Department of Electricaland Computer Engineering, Illinois Institute of Tech-

nology (IIT), Chicago, where he has established research and teaching facilities,as well as courses in power electronics, motor drives, and vehicular powersystems. He is the author or coauthor of more than 250 journal and conferenceproceeding papers, as well as several books.

Dr. Emadi is the Editor (North America) of the International Journalof Electric and Hybrid Vehicles. He has been the Guest Editor-in-Chief ofthe Special Issue on Automotive Power Electronics and Motor Drives ofthe IEEE TRANSACTIONS ON POWER ELECTRONICS. He was the GuestEditor of the Special Section on Hybrid Electric and Fuel Cell Vehicles ofthe IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY and the GuestEditor of the Special Section on Automotive Electronics and ElectricalDrives of the IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS. He hasserved as an Associate Editor for the IEEE TRANSACTIONS ON VEHICULARTECHNOLOGY, the IEEE TRANSACTIONS ON POWER ELECTRONICS, andthe IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS. He has receivednumerous awards and recognitions, including the 2003 Eta Kappa Nu Out-standing Young Electrical Engineer of the Year (a single international award)by virtue of his outstanding contributions to hybrid electric vehicle conversionby the Electrical Engineering Honor Society, the 2002 University Excellencein Teaching Award from IIT, the 2004 Sigma Xi/IIT Award for Excellencein University Research, the 2005 Richard M. Bass Outstanding Young PowerElectronics Engineer Award from the IEEE Power Electronics Society, and theBest Professor of the Year Award in 2005, as chosen by the students at IIT. Hehas also been named Chicago Matters Global Visionary in 2009.

Documents

Advanced Inter Grated Bidirectional ACDC and DCDC