Adura’s MESA Electric Powertrain Combines Controls, Switched Reluctance Traction Motor and MicroTurbine
20 April 2009
| Components of the Adura MESA powertrain. Click to enlarge. |
Adura Systems, Inc. unveiled its new MESA (Modular, Electronic, Scalable Architecture) electric powertrain for use in series hybrid, all electric and fuel cell mass transportation buses, large utility vehicles and other automotives.
Adura’s MESA powertrain features patent-pending, highly modular systems electronics, an innovative intelligent control software platform and the industry’s first scalable, field installable energy storage system that can be configured, depending upon users’ requirements, to provide 25, 50 miles or 100 miles of initial travel in pure electric mode with subsequent travel in hybrid mode.
Combined with an onboard microturbine generator for extended range, and a switched reluctance traction motor, MESA lowers emissions and reduces operating costs for buses and large utility vehicles by 50% or more compared to standard diesel powertrains, according to the company.
The first deployment of MESA is to occur in China within the next 12 months. This milestone follows a partnership agreement formed between Adura with the China Automotive Technology and Research Center (CATARC) in May 2008. Adura is also negotiating contracts in the US.
| MESA hardware. Click to enlarge. | MESA software. Click to enlarge. |
Adura’s propriety MESA consists of several key modules backed by patent-pending electronic and software technology enabling nearly 10X more electric range vs. other hybrid powertrains for mass transportation buses and large utility vehicles, according to the company. These modules include:
mCtrl. This systems control optimally and intelligently manages and controls all aspects of the modular system. Designed from the ground up, the system features power management electronics and component electronics that control the MESA modular energy storage system (mStor), electric Generator module (mGen) and the electric motor module (mDrive). mCtrl is designed to ensure high reliability, overall system efficiency, serviceability, and fault tolerance.
The system is built around a FlexRay kernel
mStor. This scalable, user installable energy storage system can be configured to provide 25, 50 or 100 miles of electric range in heavy transit buses. mStor modules can be added or subtracted to meet users varying electric mode requirements. The mStor modular battery system is fault tolerant, chemistry agnostic and allows the mixing of battery chemistries within the storage system.
Each battery pack is electronically isolated and has its own control. Each is cold, enhancing safety. The only time the battery pack wakes up is when plug into the power bus and electronics and control system. The system controller initializes the battery pack.
mBridg. This is the interface between the System, the bus accessories and infotainment. It provides the driver interfaces and the near real-time automated systems maintenance diagnosis and reports for the driver and maintenance support staff.
mGen. This 60kW microturbine generator is intelligently used to charge the energy storage system when low state-of-charge conditions arise. The flex-fuel microturbine weighs less than 500 lbs. vs. diesel engines which can weigh more than 3,000 lbs. The microturbine can use diesel, liquefied petroleum gas (LPG) or compressed natural gas (CNG). The microturbine has only one moving part and only requires service about every 8,000 hours of operation.
mDrive. A switched reluctance electric motor provides propulsion to the bus and provides regenerative breaking. The system motor is optimally controlled by mCtrl to deliver smooth, efficient acceleration and breaking. There is no transmission—the motor connects directly to the driveshaft.
Until now, powertrain developments have been initiated more from a mechanical systems integration approach, resulting in marginal fuel economy advantages and relatively few miles of electric range. Adura’s team of world-class software and electronics engineers took a ground up approach with MESA, creating intelligent electronics, software and energy storage technology that is lighter weight, incredibly fuel efficient and at a lower total cost of ownership vs. other hybrids currently offered for heavy duty vehicles. While our product can scale to many types of automotives, we are first pursuing heavy-duty buses and large utility vehicle as there is great demand from municipalities and government institutions for better solutions at lower acquisition costs that provide near zero emissions, greater fuel efficiency and reduced maintenance expenditures.
—Marv Bush, Adura CEO
The utilization of a switched reluctance traction motor illustrates Adura’s focus on software controls. SR motors can have very high power density at low cost, but have had issues with high torque ripple when operated at low speed, and noise causes by torque ripple. The first patent Adura developed, CEO Marv Bush said, was around the control for an SR motor. The engineering team invented a way to optimize the efficiency all the way through the entire speed load range map.
The ability to use an SR motor is a huge cost advantage, Bush said. At some point in the future, Adura may look at selling the motor, and if not the motor, possibly the control system.
Adura is headquartered in Menlo Park, CA and has offices in Shanghai, China.
Seems to be the correct approach. Keep up the good work Adura! Government can assist by limiting the GVW of vehicles allowed onto public roads.
Question for Adura (and we all know you are reading the comments ;))
microturbines have never been a commercial mass product because they are complicated to manufacture and maintain. How will you overcome this NOT insurmountable obstacle?
Posted by: jimfromthefoothills | 20 April 2009 at 06:54 AM
Finally, somebody is coming up with modular (up to 10 modules) battery storage onboard unit.
Since high performance battery packs is not yet a mature mass produced product, this approach is beneficial for all PHEVs and BEVs, to keep the initial vehicle price as low as possible.
Since the average PHEV and/or BEV may last up to 15 years, buyers could start with a single (2 to 5 Kwh) battery module and progressively add more modules as battery price goes down and performance goes up. In other words, the initial purchase price with a single module could be in the $15K to $25K range. The full complement of 10 modules could cost another $15 to $25 and be added progressively on an as required or as one can afford basis to benefit from future lower cost and higher performance.
The ideal would be plug-in modules that PHEV/BEV owners could buy and install themselves without having to pay any high labour cost.
Standardized plug-in PHEV/BEV modules should become as popular as current Lead car batteries.
Let's hope that all future PHEV and BEV manufacturers will get the message
Posted by: HarveyD | 20 April 2009 at 07:33 AM
Please check the Capstone turbine site. They have been producing microturbines for over ten years with several built into buses and an order for more than forty for buses in Italy. Their latest turbines put out cleaner air than they take in on LA streets and are CARB certified.
The ZEBRA batteries are hot but are in insulated cases, and are so hot that they can be cooled by the hottest air on the earth, and are so well insulated that they can run in the coldest climates as well. For buses that can always be plugged in at the end of the day, they are perfect. There is a school bus in California that is full electric and runs on ZEBRA batteries.
No buses and no cars should be full electric. There should always be at least an emergency fuel powered generator of a very few kilowatts.
The TH!NK uses ZEBRA batteries for some cars, but it was a mistake not to put an emergency fuel powered generator in it that weighed only a few pounds. They did have a contract to build a fuel cell hybrid.
If China ever decides to build a cheap sodium nickel chloride battery like the ZEBRA battery, much of the market for lithium batteries will vanish. The proposed EFFPOWER lead batteries are addequate for hybrid operation with turbines and have more energy than ultra capacitors and could be combined with small ZEBRA packs for operation with cold batteries if necessary.
Switched reluctance motors have been tested for over ten years in vehicles by SRDrives and others. They are lighter weight and require less expensive materials to build them than induction or permanent magnet motors.
..HG..
Posted by: Henry Gibson | 20 April 2009 at 12:40 PM
HG: Good to see your post. I have not seen you for a while.
Quesion: How does the EFFPOWER battery compare with Axion's for performance? Axion just signed an agreement with Exide, which should result in cost effective distribution and volume production.
Posted by: JMartin | 20 April 2009 at 01:56 PM
Sorry if this sounds critical, but I don't really see anything revolutionary about this system, evolutionary yes, but nothing new really.
Microturbines are being used by Designline in production buses today. Advanced controllers, agnostic battery systems, AC motors, etc, all are in use today. I'm not familiar with a switched reluctance motor vs a typical AC motor, but that's about it. Nothing new here as far as I can tell. Maybe they are squeezing some new efficiencies, but hybrids (in all-electric mode) are already quite efficient because electric motors are so efficient. As to their 100 mile range - sure put enough batteries in a bus and it can go forever. However, each battery you add displaces riders as you approach maximum axle weight, or you can go to untested high tech lightweight bodies. Plus, what happens when you turn on the A/C? A/C can suck more power than the drivetrain at times.
Also, there are some problems they don't mention, particularly the low efficiency of a turbine vs a diesel. A 60kW diesel doesn't weigh much more than a turbine, and is more efficient, maybe 40 vs 30%. Also the efficiency of a turbine goes way down in hot weather, just when you need it most.
It sounds like the software might be an improvement on what's currently out there.
The best solution is rapid charging at the route ends, as I've written about in www.nanobus.org. Much smaller batts, charged every hour. Sure, you need a good batt, but both Altair and Toshiba have them now. I'll be presenting a paper on this at EVS-24 in May if you're interested.
Roger
Posted by: Roger in Spain | 21 April 2009 at 09:39 AM
@jmartin
EFFPOWER batteries are designed more for brief pulses of power, but have more energy than ultracapacitors. They use the bipolar plate which removes much lead from from the battery which will make them lighter. The Axion battery has the same lead conductors as ordinary batteries and are thus heavier for the same energy than EFFPOWER. The major successful use of bipolar batteries was the XEROX film pack. Several EFFPOWER packs in parallel would give both very high power and lots of energy. EFFPOWER could reduce the inactive metallic lead in its battery to almost nothing. The actual active lead compounds have at most 1/7 the volume of the battery and the electrolyte has at least 6/7 with the case and separators needing some space as well. EFFPOWER might well use AXION or CISRO technology to improve performance.
I do not understand Axions combination unit well which seems to resemble CSIRO's combo ultra capacitor lead battery. FireFly promises also to reduce weight, and seems to have negative carbon foam plates in the market. Foam is good to hold the high volume of electrolyte compared to active material. Positive carbon foam plates are still too easily oxidized away when charging the battery. Gold foam is too expensive. FireFly also invented some type of standard positive grid protection, but does not seem to be promoting it.
The IRONCLAD (tm) technology of large lead batteries could be brought to smaller batteries to partially deal with this issue. EFFPOWER does the same thing by hiding its lead conductor in a ceramic behind the lead active material. Very high voltage EFFPOWER batteries can use the same technology as computer power supplies do to give ultra high currents at low voltages.
@roger.
You are correct about evolutionary. And engines are more efficient than turbines, but harder to maintain. Eventually the single moving part turbine generator can be built cheaper than the many part diesel engine generator. Eventually the power source for city busses can be mostly electric and the onboard generator need not be highly efficient because it is rarely used, but should always be available. NOAX proposes an interesting free piston engine, but does not use it in their proposed hybrid car. They even built a working one which $cuderi has not done.
..HG..
Posted by: Henry Gibson | 24 April 2009 at 01:47 AM
@roger
You might be interested in the Parry People Mover now going into service as a small light rail vehicle. ..HG..
Posted by: Henry Gibson | 24 April 2009 at 01:55 AM
Mike Millikin:
Lots of interesting comments on your site from Henry Gibson which makes me interested in getting to know him better.
As a Dutchman, I have had a long term interest in wind turbines. About 3-1/2 years ago we came within a hair of signing a license with http://www.turby.nl to produce their product in the US but a stroke suffered by my then 23 year old daughter forced me to become her rehab person for about a year and by then I had become more cautious about the prospects of a vertical turbine.
About 2-1/2 years ago the handwriting was on the wall that the GM Mansfield metal Center would close so I proposed that a group of local automotive vendors would buy the plant and produce a $7500 BEV. While interest at the local level in such a project was just about nil, I continued to pursue the idea because there appeared to be a close relationship between the technology to generate power with a turbine and producing power for a BEV. That technology was Switched Reluctance.
I also came to realize that building a vehicle from scratch did not make sense so I based my further activity on making a BEV out of the Ford Ka http://en.wikipedia.org/wiki/Ford_Ka a bobbed Ford Fiesta which Ford supposedly will reinvent as the Ford Festiva but is being shown as the Ford Smart http://www.fastcompany.com/1625327/ford-unveils-would-be-smart-car-competitor which is also a bobbed Festiva. This kind of vehicle will meet all safety standards and will be able to be driven on highways, something that makes the 45mph max vehicles to limiting when an otherwise city route requires a short freeway hop.
A lot of my inspiration for this project came from a book "The Lost Cord" http://nogas.org/ev/Lost_Cord/Lost_Cord.html and from several friends who own a CitiCar. In addition, my 1976 MBA thesis was on the Commute-A-Car hybrid which was ironically the name of the CityCar successor.
I have strong opinions about the current crop of BEVs and hybrids; they are useless for solving our transportation problems and our dependence on foreign oil because they are not affordable by the very people with limited financial needs who need affordable green vehicles most so finding someone like "Henry Gibson" who seems to believe like I do that switched reluctance motors and some form of more conventional battery will keep us from selling our souls to those who control the supply of rare earth metals and lithium, to collaborate on these ideas would be great.
So, wy not be the coordinator of a project to actually "design" this car on paper by finding volunteers that can do the graphics of such a car while others like myself supply the details and see if it draws interest from companies like Ford that can actually produce such a vehicle, just like they are producing a Focus BEV.
Henry Keultjes
President
Microdyne Company
Mansfield Ohio USA
Direct 419-525-1111
Posted by: Henry Keultjes | 15 February 2011 at 06:11 PM
Correction: The correct name for the new small Ford is Start.
HEnry Keultjes
Posted by: Henry Keultjes | 15 February 2011 at 06:14 PM