Presented at the EnginSoft International Conference 2010, Brescia, Italy 22 October 2010

1. Zenergy Power Inc.
The superconductor energy technology company
Multi-Objective design optimization of a Superconducting Fault Current Limiter
EnginSoft International Conference 2010
Brescia, IT
22 October 2010
[1]
Franco Moriconi, SVP Engineering
Zenergy Power Inc.
franco.moriconi@zenergypower.com

2. Overview
• About Zenergy Power
• What is a Superconductive Fault Current Limiter (FCL)
• Design and Product Optimization
• The ModeFrontier Results
• Future Work
• Q&A
[2]

3. Zenergy Power – Overview
[3]
• Zenergy Power Plc
• Admitted to London AIM (ZEN.L) 2006
• Market Cap ~ £90m
• Employees 100
• Entities incorporated
• Australia 1987 (fault current limiters)
• Germany 1999 (MBH, wires, coils, magnets)
• USA 2004 (fault current limiters)
• UK 2005 (finance, investor relations)
• Intellectual Property – Over 170 patents and applications

4. Superconductors – The Quantum Leap in Electricity
Superconductors conduct electricity with no resistance – enabling 2 key properties:
- 100% energy efficiency: no electrical losses
- 100 times current carrying capability: reduction in material use
‘Superconductivity is the enabling key technology to unlock the future of clean energy -
the „optical fibres‟ of electricity‟
Dr. Jens Mueller, CEO.
[4]
Copper
Wire
Superconducting
Wire
200 A200 A

5. Zenergy Power’s Products
[5]
Sector Application End Products
Smart Grid Transmission & Distribution Fault Current Limiters
Industrial Machines Energy Efficiency Induction Heater
Renewable Power Power Generation Generators

6. [6]
Save more than 800 barrels of oil a
year with superconducting heating
Industrial Heater – World's 1st Superconductor Energy Product
"This process is a quantumn leap for the metal processing industry –
as up to 5% of the electricity of industrialised countries is consumed
in conventional induction heaters"
Dr. Fritz Brickwedde, General Secretary of the German Enviromental Fund
German Environmental prize 2009

7. Superconductor Induction Heaters: Commercial advantages
- World‟s first industrial-scale commercial superconductor product
- High-efficiency superconductor coils: 50% reduced energy consumption
- High-power superconductor coils: 25% increased productivity
- Superconducting coils: improved heating quality
- Used globally by metals producers to heat metal
Comparison: 0.5 MW heating
requirement
Copper Induction Heater HTS Induction Heater
Investment €1.2m ≥ €1.4m
Annual electricity savings 0 €50k - €300k
Productivity increase per annum 0 €200k - €2m
Efficiency levels 40% 90%
Management calculation based on performance data provided by customer “Weseralu”
[7]

8. 8
Landmark Installation: Los Angeles, March 2009
115 kV LINE
115/12kV
Transformer
BYPASS
SWITCH
12 kV AVANTI “Circuit of the Future” - Los Angeles California
First installation in U.S. electricity grid
Operated by Southern California Edison
Installed in Avanti “Circuit of the Future”
First Energized on March 9, 2009
Supported by DOE and California Energy Commission

9. 9
Landmark Installation: Los Angeles, March 2009
FCL

10. one second
3.5 KA peak
0.2 KA load
Fault Event – 12 kV Installation in Los Angeles
Operational Experience

11. 11
American Electric Power - AEP Project
Requirements
• 138 kV
• 300 MVA
• Fault Current Limitation - 50%

12. 12
SATURABLE IRON CORE FCL
Picture-Frame Iron-Cores
AC CoilAC Coil
Boost Buck
Configuration for
single phase FCL
Operating Principle

13. Installation - Los Angeles
Proprietary [13]

14. 14
Inductive Fault Current Limiter
The equivalent FCL inductance is a non-linear function of the instantaneous line current,
and it may look like the graph below during a fault:
CLR
Constant
Inductance
-15.0 -10.0 -5.0 0.0 5.0 10.0 15.0
-0.0010
0.0000
0.0010
0.0020
0.0030
0.0040
0.0050
0.0060
+y
-y
-x +x
X Coordinate Y Coordinate
I_Limited L_cus
Equivalent Inductance
Instantaneous AC Current [kA]
FCL Inductance
is small at load current
FCL Inductance
Increases dramatically
during a fault
Operating Principle

15. Confidential & Proprietary | 15
23kA FAULT LEVEL
0.5 1 1.5 2 2.5 3 3.5 4
-50
-40
-30
-20
-10
0
10
20
30
40
50
TEST 77 - DOUBLE FAULT SEQUENCE - 20kA X/R=22, FCL IN
Time [sec]
LineCurrent[kA]
Phase A
Phase B
Phase C
0.5 1 1.5 2
-50
-40
-30
-20
-10
0
10
20
30
40
50
TEST 77 - 1.25s - 80 cycles FAULT - 20kA X/R=22, FCL IN
Time [sec]
LineCurrent[kA]
Phase A
Phase B
Phase C
-40000
-30000
-20000
-10000
0
10000
20000
30000
40000
50000
60000
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Time [s]
Current[A]
FEA - Iac No FCL
FEA - Iac With FCL
Prospective fault current = 19.2 kArms
Limited fault current = 10.26 kA (46.6% reduction)
Single phase AEP 2x1 D-core with 21mm thick tank. If' = 19.2kA. Sing;le Phase Fault Current
results.
VS = 138kV l-l Rs =34.79mΩ Xs = 4.1495Ω RLOAD = 79.5Ω X/R = 119
ACORE = 0.20m2
NAC =122 NIDC =730kAT HAC = 3.5m HCORE = 4.0m HDC = 400mm
Fault Current Waveforms

16. Confidential & Proprietary | 16
Trade-off Considerations to Meet Requirements
typermeabilirelative
lengthcoil
sectioncrosscoil
turnsACn
Inductance
AC
r
r
AC
l
A
o
l
An
L ;
2
changedensityFlux
BAndtV
t
B
Anemf
t
Φ
emf
coreAC
coreAC
B
Low Insertion
Impedance:
nac, A,
permeability
length
High Fault Current
Reduction:
nac, Acore, B

17. 17
FCL Design
Confidential and Proprietary Information
MAGNET OPTIMIZATION
HTS COIL OD 1700 mm
•Electromagnetic force in a magnet is AMPS x TURNS
•Cost of magnet is driven by Amp-turns needed and amount of cooling
•Price of conductor can be several hundreds $$ / kA-m
we need high current density to reduce cost
•For fixed current density we want to reduce conductor length (volume)
•Current Density is inversely proportional to working temperature

18. 18
multi-objective optimization
Weighted Function approach: transform the given multi-objective problem into an equivalent single-
objective problem. The solution depends on the values of the weights αi .
Multi-objective optimization problem:
i=1,…, n objectives
Sx
xg
xf
j
jk
ji
0)(
)(max
Sx
xg
xfxh
j
jk
ji
n
i
ij
0)(
)()(max
1
True Multi-objective approach: An alternative to combining metrics in a predetermined way, approach
design as the solutions defined within the n-dimensional space of the design objectives and variables.

19. 19
Pareto Frontier: definition
 With conflicting objectives, the aim is to find good compromises rather than a unique solution.
 So, this approach results in a set of solutions, called the “Pareto Frontier”.
 In any solution contained in the Pareto Frontier, none of the objectives can be improved without
deterioration of at least one other objective.
 Hence these solutions are known as “non-dominated” solutions.
Performance
C
o
s
t
Maximum Performance Solution(1)
Minimum Cost Solution (2)
Compromise Solution (3)
Non-Optimal Solution (0)
Pareto Frontier
Image courtesy of EnginSoft

20. 20
Problem Formulation: x, the variables
D_HTS
H_core
H_ac
Gap_tank
Gap_tank
HTS_OD/2
h_HTS
Tank_th
Tank_OD
Independent
1: Cryo_Gap
2: Cu_r1
3: Cu_r2
4: Cu_rad
5: D_HTS
6: Gamma1
7: Gamma2
8: H_core
9: NDC_h
10: NDC_v
11: h_ac
12: nac_h
13: r11
14: r12
15: r13
Dependent
1: HTS_th
2: H_ac
3:NDC
4: h_HTS
5: nac
6: v_ac
Constants
1: h_dc
2: v_dc
3: nac_v
4: Thick_Tank
5: Gap_Air
 Design Parameters 26+
 Variables: 21
 Independent: 15
 Dependent: 6+
 Constants: 5+
nac= nac_h* nac_v
nac_h
nac_v

21. 21
Solution
• Used modeFRONTIER®, a multi-objective optimization software
• It wraps around ANSYS, performing optimization by
• modifying the values assigned to the input variables, and
• analyzing the corresponding outputs calculated by ANSYS, using genetic
algorithms.
• For this particular problem:
• evaluated 960 Designs
• In each evaluation:
• idc kept constant at 130A
• iac 25 values : 1.25k:500:13.25kArms
• 24000 inductance calculations
• @1inductance calculation/min: 400+ hrs: 16+ days

22. 22
Results
TBbuck 5.3
HL statesteady 100_
■Pareto Frontier: Feasible Solutions Unfeasible Solutions
faultL

23. 23
Results

24. 24
Results

25. 25
Results

26. 26
Results: max performance

27. 27
Results: min cost

28. 28
Results: compromise

29. 29
Design Solution D_HTS HTS_th H_ac NDC h_HTS nac v__ac
Starting Design 1.35 0.01376 2.1014 2000 0.2425 38 0.0254
Best Performance 1.38666 0.00999 1.872 1591 0.1849 36 0.0236
Least Expensive Solution 1.13114 0.00999 1.944 1517 0.1763 36 0.0278
Best Compromise 1.08794 0.00999 1.872 1517 0.1763 36 0.0278
Design Solution BB_buck_Eff_Point Lbuck_Mean_Maximize Lbuck_Min Volume_HTS
Max Performance 36.6% 33.3% 27.5% -58.8%
Min Cost 41.4% -12.1% 17.7% -60.7%
Compromise 45.9% -6.3% 16.2% -60.7%
Design Solution CRYO_GAP Cu_r1 Cu_r2 Cu_rad D_HTS_Normalized Gamma1 Gamma2 H_core NDC__h NDC__v h__ac nac__h r11 r12 r13
Starting Design 0.1 0.05 0.05 0.0254 0.75 0.0254 0.0254 2.6 50 40 0.0553 38 0.01 0.02 0.02
Best Performance 0.0725 0.025 0.04 0.0236 0.8 0.02 0.035 2.665 43 37 0.052 36 0.044 0.027 0.009
Least Expensive
Solution 0.0725 0.045 0.015 0.0278 0.6 0.04 0.04 2.385 41 37 0.054 36 0.044 0.027 0.011
Best Compromise 0.07 0.045 0.03 0.0278 0.6 0.04 0.04 2.425 41 37 0.052 36 0.044 0.027 0.014
3 alternative designs provided, each improving the initial design under all 4 objectives:
Comparison of Output Variables
Comparison of Dependent Input Variables
Results: summary
Summary
)min(
)min(
)max(
)max(
_
_
coildc
statesteady
fault
buck
vol
L
L
B

30. 30
Thermal Optimization of HTS Coil
Initial Design Model
Copper Mass 348.5
HTC Max Temp 34.58
HTC Min Temp 31.15
HTC Avg Temp 33.19

31. 31
Thermal Optimization - Workflow
Input geometric variables of the parametric model
Output Variables
Objectives & Constraint

32. 32
Thermal Optimization – Sensitivity Analysis
Ranking- The correlation index
Line Correlation
+1=Direct Effect
-1=Inverse Effect

33. 33
Thermal Optimization
Avg Temp
Copper
Mass
All Designs

34. 34
Thermal Optimization of HTS Coil
Avg Temp
Copper
Mass Design
1105
Design
2130
Initial
Design
Design
1906
Design
1070

35. 35
Thermal Optimization – Summary of Results
Description Design
Number
% Copper Mass
Difference
% Max HTC
Difference
Initial Design 2178 0.0% 0.0%
Minimum HTC Temp 1105 -247.78% 29.15%
Compromise Design 1 2130 2.67% 18.48%
Compromise Design 2 1070 42.70% 4.34%
Minimum Copper Mass 1906 44.51% -12.32%
 Designs Comparison with Initial Design Configuration
+ % refers to reduction
-% refers to increase

36. 36
FUTURE WORK
Combine Geometry- Cooling and Magnetic Field Effects
Decreasing
Temperature

37. simply better
[37]
Franco Moriconi
SVP Engineering
Zenergy Power Inc.
franco.moriconi@zenergypower.com