Download Electric Machine Comparison for Mild Hybrid Light Vehicles with Respect to Performance and ... PDF

TitleElectric Machine Comparison for Mild Hybrid Light Vehicles with Respect to Performance and ...
LanguageEnglish
File Size17.9 MB
Total Pages97
Table of Contents
                            Introduction
	Problem background
	Previous work
	Thesis aim and contributions
	Scope
The 48 V Mild Hybrid System
	Characteristics of the 48 V system voltage level
	HEV drivetrain configurations
		Series hybrid
		Parallel hybrid
		Mild hybrid
	Electric machine operation modes in a mild hybrid drivetrain
		ICE cranking and idle stop and start
		Power generation and regenerative braking
		Power boost mode
		Coasting mode
The Electric Machines
	Basic electromagnetic theory
	Permanent Magnet Synchronous Machine
		Steady state model
		Mechanical output
		Power losses
		Control strategy
	Synchronous Reluctance Machine
		Concept of reluctance
		Steady state model
		Mechanical output and power losses
	Induction Machine
		Steady state model
		Mechanical output
		Power losses
	Thermal modeling
		Modes of heat transfer
		Lumped-parameter network modeling
Case Setup
	Operating points of interest
	Machine scaling
	Operating limits
	Optimization of PMSM model
	Simulation setup
		PMSM
		SynRM
		PMSynRM
		IM
Analysis of Performance and Vehicle Simulations
	Analysis of efficiency and losses
		Initial attempt on the IM
	Comparative evaluation of performance
	Full vehicle system simulations
		Highway drive
		City drive
Implementation and Evaluation of Thermal Models
	Lumped-parameter network models
		Stator frame and cooling
		Stator yoke
		Stator teeth
		Stator windings
		Internal air
		Air gap
		Rotor core
			PMSM
			SynRM
			PMSynRM
		Shaft
		Bearings
		Summary of thermal resistances and capacitances
	Losses in machine parts
	Transient thermal response comparison
Conclusions and Future Work
	Conclusions
	Future work
Bibliography
                        
Document Text Contents
Page 1

Electric Machine Comparison
for Mild Hybrid Light Vehicles
with Respect to Performance
and Thermal Capability
Master’s Thesis in Electrical Power Engineering

SEBASTIAN LARQVIST
HANNES ÖSTERGREN

Department of Energy and Environment
CHALMERS UNIVERSITY OF TECHNOLOGY
Gothenburg, Sweden 2017

Page 48

4. Case Setup

-1800 -1400 -1000 -600 -200 0

I
d
(A)

0

200

400

600

800

1000

1200

1400

1600

1800

I q
(

A
)

Torque (Nm)
MTPA
I

ph,max

1-7100 rpm

8000 rpm

20000 rpm

10

20

30

40

50

Figure 4.9 Results from the MTPA algorithm which shows d- and q-current values for the
torque levels available from zero to maximum speed, for the PMSynRM.

4.5.4 IM
The IM has the same stator design as the SynRM and PMSynRM, in order to avoid
saturation in the yoke region. The rotor of an IM can be designed in various of
combinations. In this work, an IM with 32 rotor bars has been used as starting
reference [40]. The design of the rotor bars is optimized through simulation sweeps
in order to reduce the rotor resistance and leakage of the IM and hence increasing
the performance. Additionally, aluminum bars is used in the rotor instead of copper
bars, in order to represent a less costly standardized IM [11].

Figure 4.10 illustrates the geometry of a rotor bar. The geometry parameters
are swept in order to find the optimal design. Initially, the ratio between b1 and
b2 is kept constant and the sweep of this parameter is presented in Figure 4.11 (a).
Secondly, the sweep of the slot height h1 is conducted and the results are shown in
Figure 4.11 (b). The width of parameter b1 is chosen for which the highest torque
was generated. The width of parameter b2 is swept while and the results are shown
in Figure 4.11 (c). Lastly, a sweep of the the bar opening width b0 is conducted
and its results are shown in Figure 4.11 (d). The slip is been optimized for each
individual parameter sweep in order to achieve maximum torque. To reach steady
state, the simulations required 12 electrical periods.

36

Page 49

(/Users/Hannes/Documents/MATLAB/E5/Master's thesis/Plots/IM Sweep/SweepB2.eps)


4. Case Setup

b0

h1

b1

b2

Figure 4.10 Rotor slot geometry.

0 0.2 0.4 0.6 0.8 1

Time (ms)

0

0.5

1

1.5

2

2.5

3

3.5

T
o
r
q

u
e
(

N
m

)

T
1mm,mean

= 1.7849 Nm

T
2mm,mean

= 2.0918 Nm

T
3mm,mean

= 2.1917 Nm

T
4mm,mean

= 2.1943 Nm

T
5mm,mean

= 1.9757 Nm

(a) Sweep of b1 = b2.

0 0.5 1 1.5

Time (ms)

0

0.5

1

1.5

2

2.5

3

3.5

T
o
r
q

u
e
(

N
m

)

T
4mm,mean

= 2.2022 Nm

T
6mm,mean

= 2.1821 Nm

T
8mm,mean

= 2.1387 Nm

T
10mm,mean

= 2.0207 Nm

T
12mm,mean

= 1.875 Nm

(b) Sweep of h1.

0 0.5 1 1.5

Time (ms)

0

0.5

1

1.5

2

2.5

3

3.5

T
o
r
q

u
e
(

N
m

)

T
1mm,mean

= 2.175 Nm

T
2mm,mean

= 2.1798 Nm

T
3mm,mean

= 2.1392 Nm

T
4mm,mean

= 2.0086 Nm

(c) Sweep of b2.

0 0.5 1 1.5

Time (ms)

0

0.5

1

1.5

2

2.5

3

3.5

T
o
r
q

u
e
(

N
m

)

T
1mm,mean

= 2.0001 Nm

T
1.5mm,mean

= 2.0139 Nm

T
2mm,mean

= 1.8828 Nm

T
2.5mm,mean

= 1.8944 Nm

T
3mm,mean

= 1.8142 Nm

(d) Sweep of b0.

Figure 4.11 Parameter sweep of IM rotor slots, at rms current magnitude of 100 A and
synchronous speed of 3000 rpm.

The final IM geometry with mesh density for the simulation setup is shown in
Figure 4.12. Data for rotor design and other machine performance are presented in
Table 4.5. The stator geometry is equal to the SynRM and PMSynRM, and can
hence be seen in Table 4.3.

37

Page 96

Bibliography

[31] P. Mellor, D. Roberts, and D. Turner, "Lumped parameter thermal model for
electrical machines of TEFC design," Electric Power Applications, IEE Proceed-
ings B, vol. 138, no. 5, pp. 205–208, Sep. 1991.

[32] S. Skoog, "Experimental and model based evaluation of mild hybrid fuel con-
sumption gains and electric machine utilization for personal vehicle applica-
tion," IEEE Conference and Expo on Transportation Electrification Asia-Pacific
(ITEC Asia-Pacific) , 2017.

[33] J. Lindström, "Development of an Experimental Permanent-Magnet Motor
Drive," Thesis for the degree of Licentiate of Engineering, Technical Report
No. 312L, Chalmers University of Technology, 1999.

[34] O. Josefsson, "Energy Efficiency Comparison Between Two-level and Multilevel
Inverters for Electric Vehicle Applications," Thesis for the degree of Licentiate
of Engineering, Chalmers University of Technology, 2013. [Online]. Available:
http://publications.lib.chalmers.se/records/fulltext/174182/174182.pdf.

[35] Ansoft Maxwell Field Simulator, (2011) "Study of a permanent magnet motor
with MAXWELL 20: Example of the 2004 Prius IPM Motor", Tutorial example
from Ansoft Maxwell, accessed 2011.

[36] D. Staton, A. Boglietti, and A. Cavagnino, "Solving the more difficult aspects
of electric motor thermal analysis in small and medium size industrial induction
motors," IEEE Trans. Energy. Convers., vol. 20, no. 3, pp. 620–628, Aug. 2005.

[37] M. Humphries, “Rare Earth Elements: The Global Supply Chain,” Congres-
sional Research Service, Dec. 2013.

[38] D. Tanaka, M. Sanada, S. Morimoto, and Y. Inoue, "Comparison of IPMSMs
Using Bonded and Sintered Rare-Earth Magnets with Different Magnet Ar-
rangements," 19th International Conference on Electrical Machines and Sys-
tems (ICEMS), Nov. 2016.

[39] T. Masuko, and I. Miki, "A novel rotor structure of IPMSM with rare earth
and ferrite magnets," 19th International Conference on Electrical Machines and
Systems (ICEMS), Nov. 2016.

[40] L. Alberti, N. Bianchi, and S. Bolognani, "Variable-Speed Induction Machine
Performance Computed Using Finite-Element," IEEE Trans. Ind. Appl. , vol.
47, no. 2, pp. 789-797, Jan. 2011.

[41] W. L. Soong, and N. Ertugrul, "Field-Weakening Performance of Interior
Permanent-Magnet Motors," IEEE Trans. Ind. Appl. , vol. 38, no. 5, pp. 1251-
1258, Oct. 2002.

84

http://publications.lib.chalmers.se/records/fulltext/174182/174182.pdf

Page 97

Bibliography

[42] MineralPrices.com, [Online]. Available: http://www.mineralprices.com. Ac-
cessed: 2017-05-24.

[43] C. Du-Bar, "Design and analysis of a fault-tolerant fractional slot PMSM
for a vehicle application," Thesis for the degree of Doctor of Philosophy in
Engineering, Chalmers University of Technology, 2016. [Online]. Available:
http://publications.lib.chalmers.se/records/fulltext/241697/241697.pdf.

[44] H. Cai, B. Guan, and L. Xu, "Low-Cost Ferrite PM-Assisted Synchronous Re-
luctance Machine for Electric Vehicles," IEEE Trans. Ind. Electron. , vol. 61,
no. 10, pp. 5741-5748, Oct. 2014.

[45] A. Nordelöf, PhD Candidate, Environmental Systems Analysis, Chalmers Uni-
versity of Technology, private communication, May 2017.

[46] H. Jin, P. Afiuny, T. McIntyre, Y. Yih, and J. Sutherland, "Comparative Life
Cycle Assessment of NdFeB Magnets: Virgin Production versus Magnet-to-
Magnet Recycling," Procedia CIRP, vol. 48, pp. 45-50, May 2016.

[47] M. Simonsen, "Metal production," Vestlandsforskning, 2009. [Online]. Available:
http://sip1.vestforsk.no/pdf/Felles/MetalProduction.pdf. Accessed: 2017-05-
29.

[48] G. Kylander, "Thermal modelling of small cage induction motors," Thesis for
the degree of Doctor of Philosophy in Engineering, Technical Report No. 265,
Chalmers University of Technology, 1995.

85

http://www.mineralprices.com
http://publications.lib.chalmers.se/records/fulltext/241697/241697.pdf
http://sip1.vestforsk.no/pdf/Felles/MetalProduction.pdf

Similer Documents