Conference-201305-Asa, E-PLL Control Technique of LLC Resonant Converter for EVs Battery Charger

8/9/2019 Conference-201305-Asa, E-PLL Control Technique of LLC Resonant Converter for EVs Battery Charger

1/5


2/5


3/5

2 2

8i L

o o

R n RQ

Z Z

= = (8)

The ratio between two inductances is

r

m

L A

L

= (9)

The normalized frequency is

swn

o

f f

f = (10)

The voltage transfer function of the system with help of thenormalized parameters is

( )

4

1 1 12 1 1 2 1

V M

An A j f nQ A f f nn

= + + +

(11)

The voltage gain is plotted for different quality factors inFigure 5. Higher quality factors give higher voltage gains. Themaximum voltage transfer gain occurs at the resonantfrequency, which depends on the load condition. Thisfrequency varies between the corner frequency and the criticalfrequency. When the quality factor is high, the resonantfrequency is close to corner frequency. At high load conditions,the output voltage can be regulated in a narrow operatingfrequency range [14-15].

Figure 5. The voltage transfer function at A=1/6

The design procedure of the converter is presented by thefollowing equations:

Transformer turns ratio is

2 2 inout

V n

V = (12)

Maximum and minimum gain values are:

max min,min , max

,out out V V in in

V V M M

V V = = (13)

The resonant capacitor value is

2r o i

QC

f R = (14)

The resonant inductance value is

1

1 2

ir

o

R L

f Q A

=

+

(15)

The magnetizing inductance value is

( )1 2i

mo

R L

A f Q =

+ (16)

Considering all the equations stated above, the Class Dhalf-bridge resonant LLC converter design parameters aregiven in Table I.

TABLE I. D ESIGN PARAMETER VALUES

Parameters Value

Input DC Voltage 240 V

Output DC Voltage 60 V

Efficiency (At Full Load) %97

Max. Output Current 20 A

Max Output Power 1.2 kW

Output Voltage Ripple


4/5

V i

S 1

S 2

D 1

D 2 I i +

-V S2

+-V S1

R

L r C

Lm

+

-

V o+

-C f

L f D 3

D 4

Var I ref

e

n:1:1

PhaseDetector

Filter

I oV o

if VCO

ControllerDriver

Figure 6. Simulation of the resonant LLC converter

As it can be seen from Figure 7, the switch voltage 2S V andresonant tank current i I is not in phase during the transient.PLL control detects the phase difference between 2S V and i I ,then it catches the resonant frequency by increasing theswitching frequency.

Figure 7. Resonant tank voltage and current waveforms before catchingresonant frequency

In steady state, the switch voltage and resonant tank currentwaveforms are displayed in Figure 8. It is shown that thevoltage and current are in phase. Hence, zero voltage and zerocurrent switching is achieved by the PLL control.

Figure 8. The voltage and current waveforms in the resonant tank

Figure 9 shows step load change and performance of thePLL control. The load resistance is changed from 3 ohm to 2ohm at 0.2 ms. The peak current in the resonant tank showed ingreen decreases and reaches steady state in less than 0.15 ms.

Figure 9. The current and voltage vaweforms with load changes

While the input voltage changes from 240 V to 260 V, theoutput voltage transient is illustrated in Figure 10. The outputvoltage is stabilized at 60 V in less than 1.5 ms.

Figure 10. Constant voltage control with input voltage changes

Figure 11. Voltage gain results in the simulation at A=1/6

1385

4th International Conference on Power Engineering, Energy and Electrical Drives Istanbul, Turkey, 13-17 May 2013

POWERENG 2013


5/5

Voltage gains are obtained from the simulations bysweeping the switching frequency. The results are plotted inFigure 11 for different output load conditions. As it can be seenfrom Figure 5 and Figure 11, analytical results and simulationresults are very close to each other.

V. CONCLUSIONS

In this paper, the PLL control technique is presented forLLC resonant converter for EVs charger systems. Systemdesign equations are explained in detail, parameters arecalculated and simulation waveforms are illustrated. Thesimulation is performed with 240 V-260 V input voltage and1.2 kW output power. Other important features of the converterinclude:

Zero voltage switching and zero current switching areensured by keeping switching frequency at the resonantfrequency.

Switching losses are minimized and maximum powertransfer is achieved.

Ripple voltages are reduced and battery is operated atreliable charging conditions.

R EFERENCES [1] L. Serrao, Z. Chehab, Y. Guezennec, and G. Rizzoni, An aging model

of Ni-MH batteries for hybrid electric vehicles, IEEE Vehicle Powerand Propulsion Conference, pp. 78-85, September 2005.

[2] A. M. Rahimi, "A Lithium-Ion Battery Charger for Charging up to EightCells," IEEE Vehicle Power and Propulsion Conference, pp. 131-136,September 2005.

[3] SAE Hybrid Committee. (2011). SAE Charging Configurations andRatings Terminology [Online]. Available: http://www.sae.org/smartgrid/chargingspeeds.pdf

[4] C. Liu, B. Gu, J. S. Lai, M. Wang, Y. Ji, G. Cai, Z. Zhao, C. L. Chen, C.Zheng, P. Sun, High-Efficiency Hybrid Full-BridgeHalf-BridgeConverter With Shared ZVS Lagging Leg and Dual Outputs in Series,IEEE Transactions on Power Electronics, vol. 28, no. 2, pp. 849-861,February 2013.

[5] D. Gautam, F. Musavi, M. Edington, W. Eberle, W. G. Dunford, AnAutomotive On-Board 3.3 kW Battery Charger for PHEV Application,IEEE Vehicle Power and Propulsion Conference, pp. 1-6, September2011.

[6]

L. Petersen, M. Andersen, "Two-Stage Power Factor Corrected PowerSupplies: The Low Component-Stress Approach," IEEE Applied PowerElectronics Conference and Exposition, vol. 2, pp. 11951201, 2002.

[7] M. K. Kazimierczuk, D. Czarkowski, Resonant Power Converters, 2nd.ed., New York: John Wiley & Sons, Inc., 2011, pp. 144, 448.

[8] F. Musavi, M. Edington, W. Eberle, W. Dunford, A Cost EffectiveHigh-Performance Smart Battery Charger for Off-Road and

Neighborhood EVs, IEEE Transportation Electrification Conferenceand Expo, pp. 1-6, June 2012.

[9] M. K. Kazimierczuk, Pulse Width Modulated DC-DC PowerConverters, New York: John Wiley&Sons, Inc., 2008, pp. 132.

[10] F. Musavi, M. Craciun, M. Edington, W. Eberle, W. Dunford, PracticalDesign Considerations for a LLC Multi-Resonant DC-DC Converter inBattery Charging Applications, IEEE Applied Power ElectronicsConference and Exposition, pp. 2596-2602, February 2012.

[11] E. Asa, Resonant Inverter Application with PLL Control Technique,M.S. thesis, Institute of Science and Technology, Gazi University,Ankara, Turkey, 2009.

[12] W. Yin, P. Irwin, D. Schweickart, Dielectric Breakdown of PolymericInsulations Aged At High Temperatures, IEEE International PowerModulators and High Voltage Conference, pp. 537-542, May 2008.

[13] W. Feng, P. Mattavelli, C. L. Lee, Pulsewidth Locked Loop forAutomatic Resonant Frequency Tracking in LLC DC-DC Transformer,IEEE Transactions on Power Electronics, vol. 28, no. 4, pp. 1862-1869,April 2013.

[14] ST Microelectronics, LLC Resonant Half-Bridge Transfer ConverterDesign Guideline, Application Note AN2450, pp. 1-7, 2007.

[15] A. Bersani, A. Dumais, S. Khare, DC/DC LLC Reference DesignUsing the dsPIC DSC, Microchip Technology Inc., Application NoteAN1336, pp. 1-82, 2010.

1386

4th International Conference on Power Engineering, Energy and Electrical Drives Istanbul, Turkey, 13-17 May 2013

POWERENG 2013

Conference-201305-Asa, E-PLL Control Technique of LLC Resonant Converter for EVs Battery Charger

Documents

Transcript of Conference-201305-Asa, E-PLL Control Technique of LLC Resonant Converter for EVs Battery Charger