1. By: Maxwell Technologies - San Diego
Tecate Training
By:
Maxwell Technologies - San Diego

2. About Maxwell www.maxwell.com Manufacturing facilities:
Capacitor Manufacturer since 1965
Manufacturing facilities:
US, Europe, Asia
Maxwell is a leading developer
and manufacturer of innovative,
cost-effective energy storage
and power delivery solutions.
Certifications:
ISO 9001:2000
ISO/TS 16949
ISO 9002

3. Table of Content
When can I use an Ultracapacitor?
What is an Ultracapacitor?
Ultracapacitor Market
Ultracapacitor Applications
Sizing your System
Sizing Examples
Guidelines to Designing an Ultracapacitor System
Summary

4. When can I use an Ultracapacitor?
Applications that require high reliability back-up power solutions
Short term bridge power seconds for transfer to secondary source or orderly shut down
Power quality ride-through to compensate for momentary severe voltage sags
Power buffer for large momentary in-rush or power surges

5. What is the difference between Power and Energy?
Power vs Energy
What is the difference between Power and Energy?

6. Application Model

7. Peak Power Shaving Peak Power Shaving
Ultracapacitors provide peak power ...
Required Power
Ultracapacitor Peak Power
Available
Power

8. Back-up Power Back-Up Power Support
Ultracapacitors provide peak power…
...and back-up power.
Ultracapacitor Backup Power
Available Power
Required Power

9. What is an Ultracapacitor?

10. Ultracapacitor Performance Characteristics
Ultracapacitors perform mid-way between conventional capacitors and electrochemical cells (batteries).
Fast Charge and Fast Discharge Capability
Highly reversible process, 100,000’s of cycles
Lower energy than a battery
~10% of battery energy
Greater energy than electrolytic capacitors
Excellent low temperature performance

11. What is an Ultracapacitor?
Ultracapacitors are:
A 100-year-old technology, enhanced by modern materials
Based on polarization of an electrolyte, high surface area electrodes and extremely small charge separation
Known as Electrochemical Double Layer Capacitors and Supercapacitors
Dielectric
Film foil
Electrode
Electrolyte
ECDL
Separator
C = er A/d
Minimize (d)
Maximize (A)
E = 1/2 CV2

12. Technology Comparison

13. Technology Comparison (page 2)
0,01
0,1 1 10
100
1000
10000
Power Density/[W/kg]
Energy Density/[Wh/kg]
Double-Layer Capacitors
10h 1h
0,1h
36sec
3,6sec
0,36sec
36msec
Lead Acid
Battery
Ni/Cd
Li-
Al-Elco
U/C
Fuel Cells

14. Ultracap vs Battery Technologies

15. Ultracapacitor Market

16. Ultracapacitor Market
Ultracapacitor World Market
Consumer Products
Digital Camera
PDA
Toys
Memory back-up
UPS
Windmill
Industrial
Stationary Fuel Cell
Automation/Robotics
Transportation
Hybrid Bus/Truck
Engine starting
Light Hybrid
Local Power
Rail

17. Available Products
Aqueous Electrolyte: ESMA, Elit, Evan, Skeleton Technologies and Tavrima
Advantages:
High electrolytic conductivity
No need for tight closure to isolate
Low environmental impact
Disadvantages:
Low decomposition voltage (1.23V)
Narrow operational range (freezing point of water)
Organic Electrolyte: Maxwell Technologies, Panasonic, EPCOS, Ness Capacitors, ASAHI GLASS
High decomposition voltage
Wide operating voltage
Low electrolytic conductivity
Need for tight closure to isolate from atmospheric moisture
Talk about symmetric vs asymmetric, Carbon cloth vs powder

18. Ultracapacitor Applications

19. Applications Automotive Traction Consumer Electronics Industry
Large Cells
Automotive
14/42 V systems
HEV
Electrical Subsystems
Traction
Regen braking
Voltage stabilization
Diesel engine starting
Consumer Electronics
AMR
PDAs
Digital cameras
2-Way pagers
Scanners
Toys
Small Cells
Industry
Power quality
Pitch systems
Actuators 7

20. Today’s Markets TRACTION INDUSTRY CONSUMER
Electric Rail Pack Braking Energy Recapture Diesel engine starting
Wind power plant pitch systems Burst power
Small cell applications Digital cameras, AMR, Actuators, Memory boards
TRACTION
INDUSTRY
CONSUMER

22. SITRAS® SES - Solution
Energy storage system:
Stationnary or on the vehicle
Time t1
Vehicle 1 is braking
Energy storage system stores the
braking energy
Time t2
Vehicle 2 is acccelerating
Energy storage system delivers the energy
Application: Time shifted delivery of the stored braking energy for vehicle re-acceleration
Solutions: Possible with either stationary or on-vehicle energy storage system
Advantage: Cost savings through reduced primary energy consumption

23. SITRAS® SES - Benefits

24. MITRAC of Bombardier Transport
MITRAC energy saver

25. Diesel Engine Cranking by Stadler
Ultracap module for diesel engine vehicles
Robust construction with voltage balancing
Easy to scale up for additional cranking power
Easy to integrate in existing housing
Easy to use, maintenance free 9

26. Wind Turbine Pitch Systems
Modern wind turbines
consist of three-
bladed variable
speed turbines
Independent
electro-mechanical
propulsion units
control and adjust
the rotor-blades
Latest technology
uses the wind not
only to produce
wind energy but
also for its own safety 9

27. Pitch System Storage Systems
Each pitch systems is equipped with an ultracapacitor emergency power supply
Ultracapacitors represent an optimum emergency power supply system due to their
Enhanced level of safety
High reliability
Efficiency
Scalability
Switch box including 2600F ultracapacitors
75 V, 81 F ultracapacitor module
4 modules are put in series to power 300 V pitch systems of 3-5 MW wind power plants 9

28. Fuel Cell Powered Fork Lift
Fork lift equipped with a fuel cell
Cell system and an ultracapacitor module
BOOSTCAP module:
48 BCAP0010
112 V, 55 F
40 kW peak power

29. Vehicle Applications of Ultra-capacitors
Distributed energy modules are located at the actuator level in the vehicle control hierarchy in close proximity to the actuator power driver
(should be within 18”).

30. Fuel Cells with Ultracapacitors
Ultracapacitors are accepted as the normal energy storage option for fuel cells
Every major automotive company in the world is testing fuel cells as an alternative drive train power system.
All significant fuel cell companies are either using or experimenting with ultracapacitors as an integral part of the system.
Several major automotive companies have declared fuel cells with ultracapacitors as their baseline system architecture. Honda and Hyundai have gone public, others we are working with have not.
“Utilizing ultracapacitors we have gained an edge in energy efficiency and throttle responsiveness over competitors that are pursuing the hybrid battery–fuel cell model”
Honda Motor Company

31. Sizing Your System

32. Data sheet

33. Data sheet

34. How to measure Ultracapacitors
To measure UC you need:
bi-directional power supply (supply/load) OR
separate power supply and programmable load (constant current capable)
voltage vs. time measurement and recording device (digital scope or other data acquisition)
Capacitance and Resistance:
Capacitance = (Id * td)/(Vw - Vf) = (Id * td)/Vd ESR = (Vf - Vmin)/Id
Vw = initial working voltage    Vmin = minimum voltage under load Id = discharge current             Vf = voltage 5 seconds after removal of load. td = time to discharge from initial voltage to minimum voltage

35. Basic Equations
Definition of Capacitance: C = Q/V (1) Charge = current * time: Q = I*t C = I*t/V (1a) Solving for voltage: V = I*t/C (2)
Dynamic Voltage: dV/dt = I/C (3)
Stored Energy E = ½ C*V2 (4)
At initial voltage Vo, Eo = ½ C*Vo2
At final voltage Vf, Ef = ½ C*Vf2
Delivered energy = Eo – Ef ΔE = ½ C*(Vo2 – Vf2) (5)
Series:
Cseries = Ccell/Nseries
Rseries = Rcell*Nseries
Rpseries = Rpcell
Parallel:
Cparallel = Ccell*Nparallel
Rparallel = Rcell/Nparallel
Rpparallel = Rpcell*Nparallel
Derivation of series capacitance value:
Ecell = ½ Ccell * Vcell2 (1)
ET = ½ CT * VT2 (2)
2*ET/ VT2 = CT (3; 2 rearranged)
ET = N* Ecell = N* ½ Ccell * Vcell2 (4)
VT = N * Vcell (5)
CT = 2*[N* ½ Ccell * Vcell2] /[N * Vcell]2 (substituting 4 & 5 into 3)
CT = Ccell /N

36. Voltage & Current vs. Time
C = 15 farad; Resr = 100 milliohm Vo = 48V; I = 30A -5 -4 -3 -2 -1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Time (sec) 20 25 30 35 40 45 50
Voltage (V)
Current (A)
Voltage
Current Vo
- Resr +
+C-
dV/dt = I/C ; dV = I*dt/C
dVtotal = I*dt/C + I*Resr
ΔE = ½ C*(Vo2 – Vf2)
dVesr = I*Resr
V = Q/C i Vf
Vmin

37. Basic Model Series/Parallel configurations Current controlled
Changes capacitor size; profiles are the same
Series configurations
Capacitance decreases, Series Resistance increases
Cs=Ccell/(#of cells in series) Rs=Rcell*(# of cells in series)
Parallel configurations
Capacitance increases, Series Resistance decreases
CP=Ccell*(# of cells in parallel) RP=Rcell/(# cells in parallel)
Current controlled
Use output current profile to determine dV/dt
dV = I * (dt/C + ESR)
Power controlled
Several ways to look at this:
Pterm = I*Vcap –I2*ESR (solve quadratic for I)
I = [Vcap - sqrt(Vcap2-4*ESR*Pterm)]/(2*ESR)
Solve for dV/dt as in current-controlled
J=W*s=1/2CV2 Solve for C.
Series:
Cseries = Ccell/Nseries
Rseries = Rcell*Nseries
Rpseries = Rpcell
Parallel:
Cparallel = Ccell*Nparallel
Rparallel = Rcell/Nparallel
Rpparallel = Rpcell*Nparallel
Derivation of series capacitance value:
Ecell = ½ Ccell * Vcell2 (1)
ET = ½ CT * VT2 (2)
2*ET/ VT2 = CT (3; 2 rearranged)
ET = N* Ecell = N* ½ Ccell * Vcell2 (4)
VT = N * Vcell (5)
CT = 2*[N* ½ Ccell * Vcell2] /[N * Vcell]2 (substituting 4 & 5 into 3)
CT = Ccell /N
Power controlled
Pterm = I*Vterm
Pterm = I*Vcap –I2*ESR
ESR*I2 - Vcap * I + Pterm = 0
I = [Vcap - sqrt(Vcap2-4*ESR*Pterm)]/(2*ESR)

38. Applications with a single energy storage component
Applications in which little total energy is required (i.e. memory backup)
Possibly used with other energy sources
Short duration, high power (i.e. pulse transmit)
Long duration, low power (i.e UPS backup)
Opportunities for high charge rates (i.e toys)

39. Applications with two energy storage components
Power vs. Energy design trade when using two components
Single component vs. two components
Engines/Fuel cells/Batteries/Solar Arrays are energy rich/power poor (or poor response)
Size these components for enough energy, system may be limited in power
Size these components for power, system may have surplus of energy
Ultracapacitors are power rich/energy poor
Size an ultracapacitor for enough energy, system may have a surplus of power
Size an ultracapacitor for power, system may be limited in energy
Two components
A primary source for energy; Ultracapacitor for power
Requires appropriate definition of peak power vs. continuous power
Load leveling applications
response time
Basic sizing
Standby applications
Automotive, Industrial, Consumer Electronics (check other presentations)

40. Ultracapacitor Aging
Unlike batteries, Ultracapacitors do not have a hard end of life criteria.
Ultracapacitors degradation is apparent by a gradual loss of capacitance and a gradual increase in resistance.
End of life is when the capacitance and resistance is out of the application range and will differ depending on the application.
Therefore life prediction is easily done.

41. Capacitance and ESR vs Frequency

42. C and ESR Temperature Dependency

43. BCAP Self Discharge

44. BCAP Cycling Capacity

45. BCAP Cycling 500’000 cycles between 1.8 and 2.7 V, 100 A
ESR (1 Hz) increase 140 % (0.49 to 0.79 mOhm
Capacitance decrease 38 % (2760 to 1780 F), 30% compared to rated capacitance

46. BCAP DC Life
Capacitance and ESR variation at U, T = 40 °C

47. BCAP DC Life
Capacitance and ESR variation at U, T = 65 °C

48. Sizing Examples

49. Example sizing 1) Define System Requirements
15 W delivered for 10 seconds
10V max; 5V min
2) Determine total energy needed: J=WS=10W*10sec=150J
a) Determine Capacitance based on: J=1/2CV2
b) Substitute the energy from above: 150J=1/2C(Vmax2-Vmin2)
c) Solve for C: C=300/(102-52)=4F
3) Add 20-40% safety margin to cover I2R losses Csystem = 4.8F
4) Calculate number of cells in series (since maximum cell voltage = 2.5V)
10V/2.5V = 4 cells in series
5) Calculate cell-level capacitance
C = Csys * # of series cells = 4.8F* 4 = 19.2F per 2.5V “cell”
6) Calculate number of cells in parallel (we will assume a 10F cell)
# in parallel = 19.2/10F = 2 x 10F cells in parallel

50. Product Strategy BOOSTCAP® Products Product Family MC Product Family
BC Product Family
PC Product Family
Product Type
Energy
Power
Product
Cells
Modules

51. Product Portfolio Offerings
Enhance application cost effectiveness by filling the product portfolio ladder - Initial focus: MC Series
Power Ladder
Energy Ladder
3000 F
3000 F
2600F
2600F
2000 F
2000 F
1500 F
1500 F
1200 F
1200 F
650 F
650 F
11 New Ultracapacitor Cells

52. New Product Portfolio for MC Series
Type
MC Series
BMOD Series
Cells
16 V Modules
48 V Modules
3000 F √
2600 F
2000 F
1500 F
1200 F
650 F
Energy
29 New Products
Power

53. Guidelines to Designing an Ultracapacitor System

54. Ultracapacitor Cell Balancing
Why Cell Balancing?
Achieve cell to cell voltage balance
Accounts for variations in capacitance and leakage current, initial charge and voltage dependent on capacitance, sustained voltage dependent on leakage current
Reduces voltage stress on an individual cell
Increase overall reliability of the individual cells

55. Ultracapacitor Cell Balancing
How to Cell Balance?
Resistor method, resistor placed in parallel, resistor value calculated at 10x leakage current for slow balance, 100x for faster balance, good for low cycle when efficiency or stand by loss not an issue
Surface Mount Resistor for low duty cycle application

56. Ultracapacitor Cell Balancing
Active method, use semiconductors to limit or balance voltage between cells, best for high duty cycle or when efficiency and stand by loss from leakage current are important, highest cell reliability option
Active cell to cell balance circuit

57. Cell Balancing Low Cost Scalable balance current 10mA, 300mA circuits
2600F cells; 4 in Series
Low Cost
Scalable balance current
10mA, 300mA circuits
Very low quiescent current (<20µA)
No on/off required
Modular installation
N cells requires N-1 circuits
Voltage independent
Low capacitance, high leakage cell
Note high and low points; low capacitance cell
1.5 hours of Vehicle cycling (~ 200A)
300mA balancer for 50 & 60mm Ø cells
10mA balancer for 5F & 10F cells

58. Cell Balancing
Three cells with one cell balancing resistor removed:

59. Ultracapacitor Packaging
Why Packaging?
Ensure proper mechanical stress
Ensure robust low resistance interconnect
Ensure proper electrical isolation
Ensure proper thermal considerations
Ensure agency compliance
Increase overall cell reliability
Reduce or eliminate maintenance requirements

60. Ultracapacitor Packaging
How to Package Cells?
Care should be taken for the electrical interconnect, a few key guidelines to follow:
Do not over torque. Over torque at the terminals may cause internal failure of contact points. For example, the Maxwell BCAP specification is 100 in.-lbs
Use similar conductor metal interconnect bus bars to eliminate galvanic corrosion.
Good surface to surface contact will reduce inter-cell resistance, reducing voltage drop and temperature stress

61. Ultracapacitor Packaging
How to Package Cells?
Cell to cell spacing should take into consideration two key points and can be accomplished by the design of the interconnect or the cell balancer:
Depending on the cell some part of the outer case may be electrically the same as one of the terminals, ensure electrical isolation and watch for rubbing components that may wear through ultracapacitor insulation, do not remove the factory installed insulator sleeve
Some air space between the cells allows convection cooling via air flow improving reliability, depends on cycle time, short duration high cycle applications may require forced air or other cooling method

62. Ultracapacitor Packaging
Electrical
Isolation
Aluminum
Interconnect
Proper Torque
and Hardware

63. Summary

64. Benefits Summary Calendar Life Cycle Life Charge acceptance
Function of average voltage and temperature
Cycle Life
Charge acceptance
Charge as fast as discharge, limited only by heating
Temperature
High temp; no thermal runaway
Low temp; -40°C

65. Benefits Summary No fixed Voc No Vmin Cell voltage management
Control Flexibility; context-dependent voltage is permitted
Power Source voltage compatibility
Examples; Fuel cells, Photovoltaics
No Vmin
Cell can be discharge to 0V.
Control Safety; No over-discharge
Service Safety
Cell voltage management
Only required to prevent individual cell over-voltage
State of Charge & State of Health
State of Charge equals Voc
Dynamic measurements for C and ESR = State of Health
No historical data required

66. www.maxwell.com Useful Links
Useful links on Maxwell Technologies Web-site:
White Papers
Technology Overview
Sizing worksheet
Application Notes
Data Sheets