Download Product lifecycle Management (PLM) is a process that manages

Design Team 10
ECE_480_FS08
Michael Kovalcik
Jamal Adams
Marvell Mukongolo
Chi-Fai Lo
Design Issues Paper
Product lifecycle Management:
Product lifecycle Management (PLM) is a process that manages production,
designing parts and documents. It helps to maximize the profit by working in the
product’s life from management to the development. Applying PLM can help to
integrate the entire product information from idea through retirement. It can be divided
in four different parts when PLM is on progress. The first stage is the ideas which
consists of the requirements, analysis and planning. It’s all based on the point of view
from the company, customer and market. The next stage of PLM is the designing part
which should come up with the detailed idea and the development for the product. For
example, we started form defining the product to the concept and the prototyping. This
part will cover for lots of engineering which include Product engineering, manufacturing,
mechanical and the electrical engineering. We have to define the way of manufacturing
after the design ideas has came out. The last part of the PLM is the maintenance and the
retirement. It should provide customers with well support information and the
maintenance. We also have to consider the disposal procedure and each individual
manufacturer’s instructions.
The Battery/Supercapacitor Hybrid System we created has been designed with
efficiency and cost effectiveness at the top of our list of requirements. This system was
designed with the backdrop of the current, petroleum induced energy crisis. The target
customer for our product is any manufacturer of electric vehicles who is looking to
maximize the energy efficiency for their vehicles while minimizing their dependency on
oil based fuel. The Battery/Supercapacitor Hybrid System we have developed stretches
the battery’s duty cycle, which extends the time period between rechargings. This results
in long-term savings on electricity costs and usage. Extending the duty cycle also
increases overall battery life. This means that the system actually prolongs the need to
purchase a replacement battery system.
In order to gain valuable knowledge about product lifecycle and performance, a
discount could be applied to a the price of a new Battery/Supercapacitor Hybrid System if
the old one is returned to the manufacturer at the end of its operational use. This would
also reduce the possibility of the system being disposed of in a landfill or by some other
undesirable means. The information received from this process could be collected by
and/or distributed to the designers. This would be extremely useful for improving of
efficiency of future hybrid systems.
Another way to employ PLM of the Battery/Supercapacitor Hybrid System would
be for the design firm to purchase several different vehicles which use their
Battery/Supercapacitor Hybrid System. These vehicles could be loaned to company
employees on an “as needed” basis or as job perk. This would ensure that the designers
had some contact and personal experience with the end market item, allowing them to
gain insight into possible improvements or new features.
The use of super capacitors saves valuable space and has a reduced weight to that
of a comparable, all battery system currently used in mass-produced electric vehicles.
Prolonging battery life also means that there will be less risk of environmental hazards
from waste batteries, conservation of natural resources through more efficient energy
usage, and fewer dollars spent on increasingly costly oil based fuels. This technology is
currently in its infancy and is sure to have a major impact on the global auto industry as it
matures and the cost of oil continues to rise.
Product Safety:
Safety is a major concern in the design of any product intended for use by
consumers. This concern is greatly intensified when the product is composed of a highly
reactive and volatile material such as lithium. Add to that a high energy density, high
current, relatively high voltage, and the tremendous forces involved in a high speed
vehicle collision, and you have the makings of a potentially catastrophic event.
Steps can be taken during the design process to ensure safety exists for even the
most dangerous consumer devices. Some of the main factors influencing safety on the
design level are legislation, liability, added cost, and effects on overall performance. The
nature of the project undertaken by Design Team 10 is to improve upon current
technology by combining advanced battery technology and new capacitor technology that
has improved capacitance by two or more orders of magnitude (μF to F). Any time new
technology is introduced to the consumer markets, the potential safety hazards may lay
yet undiscovered. Consumers are at an increased risk of danger because of the general
sense of unfamiliarity with these products.
There are an infinite number of ways one may be injured by any product. For a
Hybrid Battery/Supercapacitor System, the main concern is centered around the rapid
discharge of electricity from the system through short circuiting of the terminals or
connected nodes, resulting in a fault current.
- Supercapacitors:
This system utilizes a supercapacitor module manufactured my
Maxwell Technologies that is rated at a voltage level between 48.6 and 51.0 volts and at a
capacitance of 165 Farads with a factory measured capacitance of 172.3 Farads! This is a
very high amount of capacitance, and it may be difficult to visualize just how dangerous
it can be. This fact was the major influence behind Design Team 10s use of the factory
constructed, fully enclosed Maxwell BMOD0165P48B module, rather than constructing
one from individual parts. Another advantage of using this module is that it has the builtin safety features of voltage monitoring and individual capacitor balancing and thermal
disconnect protection. These features help prevent failure on an individual component
level and add to the overall safety of the system. It would have been very difficult for us
to design and implement these safety features on our own given the single semester time
frame and only four team members.
- Cells:
Rechargeable lithium cells contain highly reactive lithium, making them
more dangerous than cells utilizing other rechargeable cell technologies. Because of the
increased safety risk, both lithium ion (Li-Ion) and lithium polymer (Li-PO) batteries
require the inclusion of four safety features to reduce the risk of fire or explosion:
-
Shutdown Separator (Disables a cell if its temperature is too high)
-
Tear-Away Tab (Disables a cell if its internal pressure is too high)
-
Vent (Releases built up internal pressure in a cell)
-
Thermal Interrupt (Disables a cell if it is being overcharged or if the current
level used to charge it is too high)
Aside from increasing the overall complexity of these cells, these safety features take up
space, add weight, and limit design options. Because the activation of a safety feature
can permanently and irreversibly disable a cell, rechargeable lithium batteries usually
include active circuit technology for protection, especially during the charging cycle.
- Battery:
The 51.8 volt, 21 amp/hour, lithium polymer battery, used in this project,
is another potentially dangerous part of the hybrid system. This is just slightly over the
suggested ECE 480 voltage limit of 50 volts, and is three or four volts above our target of
48 volts. The main reason for this is the general unavailability of a 13 cell, 48.1 volt
Protection Circuit Module or PCM. The PCM is an integral part of any rechargeable
lithium battery. It is responsible for protecting the battery from overcharge or discharge,
unbalanced cell voltage, short circuiting of the terminals, and can include temperature
monitoring and a remaining charge display. These features help to extend Li-Ion and LiPO battery life by keeping the cells within their rated limits.
- Load:
The load requirement of one Kilowatt is, perhaps, what makes the safety
concerns for this project more important than most. This arbitrary goal has created many
potential landmines and obstacles for the designers. First of all, 1 kW is a lot of power!
All of the components used in the hybrid system, and especially the load, have to be rated
to handle 1 kW of power. A high rating increases the price and size of all the
components while decreasing the selection and availability, leaving the designer with
fewer options. Of significant importance is the usage of the proper gauge of the wire to
connect the main system components together. Failure to do so will result in overheating
and system failure. The two, 5 Ω resistors that are placed in parallel to comprise the peak
resistance of 2.5 Ω have to dissipate the full Kilowatt. It was suggested that the design
team use the heating element from an electric stove for the load resistance and still may
be an added feature in a future system. The load also contains several higher resistance
resistors, relays, and a logic controller to manage it all.
- General:
An important safety feature often overlooked is insulation. All exposed
wire, connections, and node surfaces are a potential accident waiting to happen. The
inclusion of circuit breakers, fuses, and emergency shutoff switches are generally good
safety features to include when designing an electrical system. A digital, central
monitoring system is a great safety feature to have, on top of those listed above,
especially in high power applications, such as this.
Product Liability:
When a company puts a product into production they are liable for whatever harm
defects in that product cause. Defective products can harm systems that they are placed
in; for example a defective microcontroller in a car can cause a malfunction in the cruise
control system. Defects not only cause damage to systems they can also cause injury or
even worse death. When a company places a defective product on the market they risk
being sued or fined out of existence. This is why it is very important to take every
precaution there is to make sure no defective products make it to market.
There are many things that can go wrong with a system with such high power
output. For starters our super capacitor module has flammable chemicals inside it, which
can be very hazardous to the user of this system if it is not properly installed. A
hazardous chemical spill due to cracks in the frame of the module can also occur if the
installer mishandles the module. This system will have enough current going through it to
cause death. Faulty wiring can lead to damage of the system and peripheral components
attached to it. Arcing can occur if current is not regulated properly at the super capacitor
module. This can cause fires or electrocute any person within close proximity to the
system.
In order to prevent any damage from our system every worst case scenario has to
be thought of and preventative measures have to be put in place. To prevent chemical
leaks and damage to the super capacitors, the module will be placed in an open area of
the system and screws will tie the module down to the base. Keeping the module in an
open area reduces the risk of anyone working on the system from hitting the module by
mistake while working on the other components. The wires connecting the components
will be the proper gauge to handle 21+ amps. During shipping the battery module and the
super capacitor module will be drained of all charge and grounded to prevent any
accidental discharge. The safety of the use the system will be placed in a protective case
which will prevent unauthorized hands from coming in contact with the system.
Environmental Issues:
We are using lithium polymer cells, which have been classified by the federal
government as non-hazardous waste. Unlike their counterparts, lithium polymer batteries
are safe to dispose in the normal municipal waste system, although recycling is still
recommended. Other batteries contain hazardous materials, which make them illegal to
dispose of in the normal municipal waste system. These types of batteries have to be
taken to the recycling center to be recycled.
Supercapacitors are environmentally friendly, which means they can be disposed
of without any damaged done to the environment. Due to the ability of supercapacitors to
charge and discharge thousands of times, our hybrid system will allow the battery life to
be extended. This extension in battery life will reduce the number of batteries being used.
Therefore, the hybrid system will be more advantageous to use in more systems now, in
order to reduce the harmful battery waste in landfills.
Sources:
PLM:
http://www.product-lifecycle-management.com/plm-orientation.htm
http://en.wikipedia.org/wiki/Product_lifecycle_management
Product Safety:
http://www.mpoweruk.com/lithiumS.htm
http://en.wikipedia.org/wiki/Lithium_ion_polymer_battery
http://www.nexergy.com/battery-density.htm
http://en.wikipedia.org/wiki/Lithium_ion_batteries
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=4345
Product Liability:
http://www.supercapacitors.org/
http://www.csiro.au/science/Supercapacitors.html
http://blogs.computerworld.com/node/3285
Environmental Issues:
http://en.wikipedia.org/wiki/Energy
http://www.ehso.com/ehshome/batteries.php
http://www.grinningplanet.com/2004/12-21/battery-recycling-article.htm