Building A Diesel Electric Hybrid Conversion Kit

70518 Views 33 Replies 14 Participants Last post by 26it073, 4 mo ago

GreenEnergyConversions

Discussion Starter · Mar 13, 2012 (Edited)

Hello all.

This is my first post to this forum so please excuse this post if it happens to be in the wrong section. I am currently in the design and early building phase of a Diesel Electric Hybrid conversion kit for cars and trucks and I am looking to see what kind of market is out here for this kind of product. I have very customized parts that will enable me to compete and beat many true EV conversion kits (I know, blasphemy).

Diesel engine is going to be a twin cylinder, water cooled, turbo charged, intercooled, 0.8L diesel engine. The engine already meets EPA Tier IV specs. Max rpm is 3600. The engine is further enhanced by several scientific technologies (like engine coatings, ect...). Looking at 50 miles per gallon minimum fuel efficiency. Other technology is being created to increase this above 60 miles per gallon.

Generator will be 12kw to 15kw and will produce all power required to cruise a vehicle at 90 MPH at rated fuel efficiency.

Using a permanent magnet motor, 3 phase, 120V AC drive assembly with an IVT (already in negotiations with company for rights). Total electric motor power will be 20KW nominal, 40KW Max. Also going to integrate the gear train into the electric motor for an IVT gear motor, though this is in the advanced stages of the kit. Also considering a Warp11 with Solitron controller.

Battery pack is small, 4KWH, and only used for acceleration of the vehicle. Considering ultracapacitors, but they seem expensive when you consider the load balancing and charging electronics needed. Regen breaking captures braking energy.

As I build the prototype, I will update this post with pictures. My first conversion is going to be a 1997 Mitsubishi Eclipse, converted to a RWD via the GSX rear end. I blew the engine and decided it was time to follow my dream.

I look forward to your comments and suggestions if you have any. You can follow me through my website as well if you so choose; www.greenenergyconversions.com.

Thanks in advance,

Daniel

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charliehorse55

· #7 · Mar 14, 2012

GreenEnergyConversions said:
Generator will be 12kw to 15kw and will produce all power required to cruise a vehicle at 90 MPH at rated fuel efficiency.

Nope.

15kW will get to you to 60 mph in a small car. Even if you have a really light/small car with low rolling resistance tires it will still take about 20kW to cruise at 90 mph. With an average car it's closer to 40kW.

At 90 mph air resistance is really killer, it really starts to use lots of power.

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charliehorse55

· #10 · Mar 14, 2012

GreenEnergyConversions said:
Charliehorse55,

Thanks for your input. These figures were based on some EVs I used as test vehicles in order to get some "real world" data. Current draw at 90 mph at 120 volts with radio, ac, and lights was just under 120 amps. This was with regular lead batteries in a Mitsubishi Eclipse EV. Electric motor was attached to a manual transmission (and an IVT once the owner and I reach a license agreement). If you have different data, I certainly welcome it. 40kw is a lot of power, roughly 50 hp. I know that running a car at 90 mph takes some power, but 50 hp sounds high. Based on my calculations, it would take about 31 hp to travel at 40.2 m/s (90 mph). 31 hp is equal to 23KW. I actually believe this might be a little high, but I may be wrong. I plan on using 15kw generator on the engine for a safety margin against these issues.

My diesel engine has plenty of power available (pushing 35 hp at 3600 rpm). I overpowered the diesel engine compared to the generator for just this reason. If my calcs are wrong, or the real world gets in the way, I can simply just adjust the gen size and compensate. If needed, I have a 3 cylinder turbocharged diesel that can put out over 50 HP, which is what I had planned on using for my F150 supercrew conversion. It is much heavier though so I would rather keep it for the truck.

I really appreciate your comments and welcome them all, good or bad. This will help me in the long run make a better product.

There is absolutely no way that data is correct, there must have been a mistake. Many people on these forums record between 200 and 300 Wh/mile as an average power consumption. If you claim to be using 15kW to go 90 mph you are claiming an energy efficiency of 160 Wh/ mile. I highly doubt you would manage to achieve higher efficiency than everyone else on this forum while travelling at 90 mph.

I have written a simulator that factors in air resistance, rolling resistance, drivetrain inefficiencies as well as many other lesser factors (IE Air temperature). Using the figures for a BMW 328i (which is a car that gets 6.5 L/100km), I get 40kW required to cruise at 90 mph. Even if I use the parameters of the Insight hybrid (The most efficient mass produced car ever made) I still get around 21kW required for cruise.

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charliehorse55

· #13 · Mar 14, 2012 (Edited)

For the BMW 328i:

0.29 Cd
2.08 m^2 area
1600 kg weight
0.01 Rolling resistance
25C air temperature
0.88 Drivetrain efficiency (direct drive with AC motor, for DC motor + tranny closer to 0.75)
500W of accessory load (not dependent on speed)

Code:

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charliehorse55

· #15 · Mar 14, 2012

GreenEnergyConversions said:
Thanks. We shall see the results soon enough.

Based on your calculations, my 40KW motors will not handle the requirements as set forth by you. I was looking at a 11" Netgain before I started working with the permanent magnet motors. I left the netgain due to no regen braking available. The permanent magnet motors I found do have the ability. Looks like I may just combine a few in series. What motor would you suggest to enable my vehicle to reach 90MPH?

If you are looking at AC, try Evo-electric or Remy (expensive when purchased individually, cheaper perhaps if you can get a contract to purchase a larger number at one time).

Keep in mind you will need a fairly high voltage pack to be able to overcome back EMF at those high speeds. AC motors tend to like battery packs in the 600-900V range.

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charliehorse55

· #20 · Mar 18, 2012

GreenEnergyConversions said:
What is the advantage of using a larger electric motor with 1 gear reduction (other than simplicity) vice a smaller electric motor and a transmission that is designed for an electric motor?

Not having a transmission allows:

-Higher efficiency
-Lower Cost
-Lower Weight
-Simplicity

Most manufacturers reduce the size of the motor by allowing very high RPM. This requires a very high input voltage to the controller to overcome back EMF, but since OEMs generally use high voltage systems this is not an issue.

Transmissions on an EV are a bad idea. They are only relevant in the hobbyist community where you have DC motors (and their limited RPM range).

Tesla's cars all have redlines around 16,000 RPM!

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charliehorse55

· #24 · Mar 19, 2012

Every mechanical component has losses. Adding a transmission decreases the overall efficiency of the system. It also adds 50kg or so of weight, and adds more complexity to the car.

It really isn't a matter of opinion, there is a reason ALL commercial EVs use direct drive.

Tesla Roadster/Model S/Model X
Chevy Volt
Nissan Leaf
GM EV1
Toyota RAV4 EV v1 & v2
Fisker Karma
etc..

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