Switched Reluctance pancake EV drive-train - DIY Electric Car Forums
Go Back  

DIY Electric Car Forums > General Forum > EV News

Register Blogs FAQ Members List Social Groups Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 04-13-2017, 01:56 PM
henrykeultjes henrykeultjes is offline
Junior Member
 
Join Date: Apr 2017
Location: Mansfield Ohio USA
Posts: 2
henrykeultjes is on a distinguished road
Default Switched Reluctance pancake EV drive-train

Looking at a recent Automobile magazine article about electric cars from the automobilemag site (PM for details)


and the beginning comments "As it stands today, battery electric vehicles (BEVs) are little more than loss-making goodwill devices" and at the end "Research tells us that in 15 years time, 65% of the car-buying population will consider a BEV. Today that number is below 5 percent."

Given growth like that, it seems logical that alternatives to the current electric motors will receive strong consideration because, as that article states near the end, "EVA2 models will be no more expensive than comparable gas or diesel models."

Considering that Switched Reluctance Motor/Generator (SRMG) are powered by DC, generate DC and that batteries can only be charged with DC, the incentives for using SRMGs seem to be enough to invest in the development of SRMG based automotive drive-trains, especially as a means of reducing both weight and cost.

The design of the Switched Reluctance based drive-train depicted in the attached illustrations are available for use by anyone to use (PM for details) Very much like Open Source in software. My expectation is for others to build on this design and share their additions, including a suitable circuit design, with others, as I am willing to elaborate to the best of my ability on the design details. Tesla, Toyota and others have already made their patent portfolios available to others and this design is offered in a similar vein.

Electric Vehicles (EVs) have gained their popularity mostly because of their positive environmental impact. However, in a 90 million unit vehicle annual world market, the environment can be helped only when EVs gain a substantial percentage of that market. If that is to happen, they need to be more in the price range of the Chevy Spark and similar vehicles that can be bought for under $15,000 (in Mansfield Ohio for under $11k) or the Ford Ka, my original target for this design.

This Creative Commons submission is a way of helping anyone, wanting to help that environmental goal, build on this submission.

Pictured in the attached illustration #1 is the Switched Reluctance Motor/Generator (SRMG) in RED on top of the differential, just for mentally illustrating, the rear of a Ford Escape Four-Wheel Drive or similar, turned vertical, rather than horizontal, as they are normally deployed, and without the viscous clutch.

1. An SRMG is powered by DC, generates DC in its regenerative charging mode and, of course, batteries can only be charged with DC.

2. A SRMG does not require an inverter and, because of 48 Volt automotive technology being heavily pursued, DC to DC and intelligent charging could reduce the cost of the overall BEV drive-train. Intelligent charging in this case means that electricity "drips" from the generator to an electronic accumulator of sorts, perhaps a capacitor, that "flips" a "unit" of the accumulated power into the battery at whatever "flip" it is set for.

3. A pancake configuration is more torqy

4. You can see in illustration #2 the rotor and stator are modular, typically magnetic steel based, components that are captured in aluminium castings.

5. This design allows both the motor and the generator to be engaged in phases so that employing one of the, for example, four phases produces minimal torque or braking while deploying all, for example, four phases produces maximums. Those phases need to be balanced, of course.

6. SRMG's do not use environmentally problematic rare earth materials.

7. Using aluminium to "stretch" the poles reduces the overall weight.

8. The aluminium reduces the undesirable reluctance interference to the adjoining poles.

9. The aluminium castings allow more effective cooling channels than totally steel would, and those channels will become part of the climate control system.

10. The pancake configuration sits directly on top of the pinion shaft to the ring-gear eliminating the typical EV 90 degree gearing from the motor to the differential. Gearing could be inserted there, if desirable.

11. Torque vectoring clutches, preferably based on intermittent electro-magnetic slipping, rather than constant electromagnetic activation that takes more current, could be used instead of a differential.

12. The pancake configuration on top of the differential allows the SRMG to be bolted to the differential through the bottom of the enclosed compartment that holds the SRMG and controller thus physically separated from the rest of the drive-train.

13. That compartment will be clean and out of the mud capturing additional heat for climate control purposes, rather than wasting that energy to the atmosphere. Cooling can, of course, be done with a, preferably scroll compressor based, heat-pump like made by Copeland Division of Emerson in Sydney Ohio.

16. Image #3 attached is an illustration of a standard Switched reluctance device where the poles face each other, rather than where the rotor poles run through u-shaped stator poles that have the coils inside the bottom of the U as shown in RED in the animation, image #4 - in email #2

15. The Regenerative Braking function of an SRMG driven electric vehicle is, of course, identical to the generator function of the witched Reluctance Generator (SRG) in a wind-turbine.

Therein lies the rest of the story. How Henry Keultjes pursuing development of a wind-turbine came upon this EV drive-train.

A write-up about rationale of the EVs and the ability of car companies to exploit the very same manufacturing technologies like stamping, die casting and even electronics can be readied in a day or two.

Henry Keultjes will be glad to share further details under the same Creative Commons license through DIYElectric Car or <keultjesh@gmail.com>

Henry Keultjes
Mansfield Ohio USA
Direct 419-525-1111
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old 04-19-2017, 08:50 PM
Karter2 Karter2 is offline
Senior Member
 
Join Date: Nov 2011
Posts: 1,258
Karter2 is on a distinguished road
Default Re: Switched Reluctance pancake EV drive-train

What happened to the "attached diagrams" ??
Reply With Quote
  #3  
Old 04-19-2017, 09:52 PM
major's Avatar
major major is offline
Senior Member
 
Join Date: Apr 2008
Location: Ohio, USA
Posts: 7,291
major is a jewel in the roughmajor is a jewel in the roughmajor is a jewel in the rough
Default Re: Switched Reluctance pancake EV drive-train

Quote:
Originally Posted by henrykeultjes View Post
Looking at a recent Automobile magazine article about electric cars from the automobilemag site (PM for details)


and the beginning comments "As it stands today, battery electric vehicles (BEVs) are little more than loss-making goodwill devices" and at the end "Research tells us that in 15 years time, 65% of the car-buying population will consider a BEV. Today that number is below 5 percent."

Given growth like that, it seems logical that alternatives to the current electric motors will receive strong consideration because, as that article states near the end, "EVA2 models will be no more expensive than comparable gas or diesel models."

Considering that Switched Reluctance Motor/Generator (SRMG) are powered by DC, generate DC and that batteries can only be charged with DC, the incentives for using SRMGs seem to be enough to invest in the development of SRMG based automotive drive-trains, especially as a means of reducing both weight and cost.

The design of the Switched Reluctance based drive-train depicted in the attached illustrations are available for use by anyone to use (PM for details) Very much like Open Source in software. My expectation is for others to build on this design and share their additions, including a suitable circuit design, with others, as I am willing to elaborate to the best of my ability on the design details. Tesla, Toyota and others have already made their patent portfolios available to others and this design is offered in a similar vein.

Electric Vehicles (EVs) have gained their popularity mostly because of their positive environmental impact. However, in a 90 million unit vehicle annual world market, the environment can be helped only when EVs gain a substantial percentage of that market. If that is to happen, they need to be more in the price range of the Chevy Spark and similar vehicles that can be bought for under $15,000 (in Mansfield Ohio for under $11k) or the Ford Ka, my original target for this design.

This Creative Commons submission is a way of helping anyone, wanting to help that environmental goal, build on this submission.

Pictured in the attached illustration #1 is the Switched Reluctance Motor/Generator (SRMG) in RED on top of the differential, just for mentally illustrating, the rear of a Ford Escape Four-Wheel Drive or similar, turned vertical, rather than horizontal, as they are normally deployed, and without the viscous clutch.

1. An SRMG is powered by DC, generates DC in its regenerative charging mode and, of course, batteries can only be charged with DC.

2. A SRMG does not require an inverter and, because of 48 Volt automotive technology being heavily pursued, DC to DC and intelligent charging could reduce the cost of the overall BEV drive-train. Intelligent charging in this case means that electricity "drips" from the generator to an electronic accumulator of sorts, perhaps a capacitor, that "flips" a "unit" of the accumulated power into the battery at whatever "flip" it is set for.

3. A pancake configuration is more torqy

4. You can see in illustration #2 the rotor and stator are modular, typically magnetic steel based, components that are captured in aluminium castings.

5. This design allows both the motor and the generator to be engaged in phases so that employing one of the, for example, four phases produces minimal torque or braking while deploying all, for example, four phases produces maximums. Those phases need to be balanced, of course.

6. SRMG's do not use environmentally problematic rare earth materials.

7. Using aluminium to "stretch" the poles reduces the overall weight.

8. The aluminium reduces the undesirable reluctance interference to the adjoining poles.

9. The aluminium castings allow more effective cooling channels than totally steel would, and those channels will become part of the climate control system.

10. The pancake configuration sits directly on top of the pinion shaft to the ring-gear eliminating the typical EV 90 degree gearing from the motor to the differential. Gearing could be inserted there, if desirable.

11. Torque vectoring clutches, preferably based on intermittent electro-magnetic slipping, rather than constant electromagnetic activation that takes more current, could be used instead of a differential.

12. The pancake configuration on top of the differential allows the SRMG to be bolted to the differential through the bottom of the enclosed compartment that holds the SRMG and controller thus physically separated from the rest of the drive-train.

13. That compartment will be clean and out of the mud capturing additional heat for climate control purposes, rather than wasting that energy to the atmosphere. Cooling can, of course, be done with a, preferably scroll compressor based, heat-pump like made by Copeland Division of Emerson in Sydney Ohio.

16. Image #3 attached is an illustration of a standard Switched reluctance device where the poles face each other, rather than where the rotor poles run through u-shaped stator poles that have the coils inside the bottom of the U as shown in RED in the animation, image #4 - in email #2

15. The regenerative braking function of an SRMG driven electric vehicle is, of course, identical to the generator function of the witched Reluctance Generator (SRG) in a wind-turbine.

Therein lies the rest of the story. How Henry Keultjes pursuing development of a wind-turbine came upon this EV drive-train.

A write-up about rationale of the EVs and the ability of car companies to exploit the very same manufacturing technologies like stamping, die casting and even electronics can be readied in a day or two.

Henry Keultjes will be glad to share further details under the same Creative Commons license through DIYElectric Car or <keultjesh@gmail.com>

Henry Keultjes
Mansfield Ohio USA
Direct 419-525-1111
Hi henry,

That's interesting. Loaded with misinformation followed with bad ideas. But please prove me wrong. For instance, explain or reference a treatise on how aluminum can "stretch" (7) the poles or reduce undesirable reluctance interference to the adjoining poles (8) in switched reluctance machines.

Regards,

major
Reply With Quote
 
  #4  
Old 04-20-2017, 06:20 PM
brian_ brian_ is offline
Member
 
Join Date: Feb 2017
Posts: 89
brian_ is on a distinguished road
Default Re: Switched Reluctance pancake EV drive-train

With no diagrams, there is no useful contribution here. Even with diagrams, it is not obvious that there is any original content, as switched reluctance machines have been around for a very long time.

Quote:
Originally Posted by henrykeultjes View Post
1. An SRMG is powered by DC, generates DC in its regenerative charging mode and, of course, batteries can only be charged with DC.

2. A SRMG does not require an inverter...
A switched reluctance machine is switched - that means it does not run on direct current; it runs on the output of multiple phase outputs of the controller... which is effectively the same as an inverter used to run a three-phase AC PM motor, or the controller of a electronically-commutated DC PM motor.

Quote:
Originally Posted by henrykeultjes View Post
... because of 48 Volt automotive technology being heavily pursued, DC to DC and intelligent charging could reduce the cost of the overall BEV drive-train. Intelligent charging in this case means that electricity "drips" from the generator to an electronic accumulator of sorts, perhaps a capacitor, that "flips" a "unit" of the accumulated power into the battery at whatever "flip" it is set for.
The reference to 48 volts suggests that the author has negligible understanding of electrical power. Huge currents resulting from a low operating voltage are not desireable.

The final "drips and flips" stuff just looks like nonsense.

Quote:
Originally Posted by henrykeultjes View Post
6. SRMG's do not use environmentally problematic rare earth materials.
This is the only advantage I see in a SRM. The same is true of induction motors, yet all serious production EVs use PM motors.

Edit note: as discussed in the following posts, Tesla is the exception. Thanks to Duncan for catching my error.

Last edited by brian_; 04-20-2017 at 08:40 PM.
Reply With Quote
  #5  
Old 04-20-2017, 06:35 PM
Duncan Duncan is offline
Administrator
 
Join Date: Dec 2008
Location: Southland New Zealand
Posts: 4,441
Duncan will become famous soon enough
Default Re: Switched Reluctance pancake EV drive-train

Quote:
Originally Posted by brian_ View Post
This is the only advantage I see in a SRM. The same is true of induction motors, yet all serious production EVs use PM motors.
Really? - I was under the impression it was the opposite and that Tesla and all of the others used induction motors

Some of the older hybrids used PM motors
Reply With Quote
  #6  
Old 04-20-2017, 07:04 PM
ishiwgao ishiwgao is offline
Member
 
Join Date: May 2011
Posts: 76
ishiwgao is on a distinguished road
Default Re: Switched Reluctance pancake EV drive-train

Quote:
Originally Posted by Duncan View Post
Really? - I was under the impression it was the opposite and that Tesla and all of the others used induction motors

Some of the older hybrids used PM motors
did read somewhere (a long time ago) that inductions were cheaper than PM motors hence used by many manufacturers, though not as powerful or efficient or something of that sort compared to PM.
Reply With Quote
  #7  
Old 04-20-2017, 07:23 PM
brian_ brian_ is offline
Member
 
Join Date: Feb 2017
Posts: 89
brian_ is on a distinguished road
Default Re: Switched Reluctance pancake EV drive-train

Quote:
Originally Posted by Duncan View Post
Really? - I was under the impression it was the opposite and that Tesla and all of the others used induction motors

Some of the older hybrids used PM motors
Ah, good catch. Tesla does apparently still use an induction motor, probably because it's cheaper, especially in large (for cars) sizes, and because their initial motor and controller partner used induction motors.

Toyota hybrids, GM hybrids and the Volt Spark EV and Bolt, current Honda hybrids, and the Mitsubishi i-MiEV use PM motors, for best efficiency; rotor design details and magnet design have changed over the generations of Toyota hardware, but they're still PM as far as I know. The rare-earth magnets are an expensive and problematic part of the design. Honda is working on methods to reduce or eliminate the use of rare-earth elements, but still uses magnets.

The Nissan Leaf motor is usually described as "synchronous", which applies to any PM motor as well as some non-PM AC designs, but non-PM AC synchonous motors are impractical for cars and diagrams (including one in this forum) call out the rare-earth magnets in the rotor. Here's an article from the introduction of the Leaf:
Nissan LEAF EV and What is a Permanent Magnet AC Motor?

Because the stator is the same and even the rotors look externally similar in PM and induction designs, it can be hard to tell which type a motor is, without an explicit statement in the specifications.


To be clear, while I have great reservations about the value of the post which started this thread, I do think that non-PM motor designs (induction and switched reluctance) are valuable in the right circumstances and may be even more valuable with development.

Last edited by brian_; 04-20-2017 at 08:45 PM. Reason: Added Volt to list of GM vehicles with PM motors
Reply With Quote
  #8  
Old 04-20-2017, 07:25 PM
henrykeultjes henrykeultjes is offline
Junior Member
 
Join Date: Apr 2017
Location: Mansfield Ohio USA
Posts: 2
henrykeultjes is on a distinguished road
Default Re: Switched Reluctance pancake EV drive-train

Sorry folks, but I am not good at dealing with all those negatives. I am not a guy that went to Delft but I have ideas and a fairly good understanding of what might be possible and this post was submitted in that vein. My email address is on the post and if someone is truly interested in pursuing this and make it work, email me because I will not be back on this site. Henry
Reply With Quote
  #9  
Old 04-20-2017, 07:39 PM
dcb dcb is offline
Senior Member
 
Join Date: Dec 2009
Posts: 1,865
dcb is on a distinguished road
Default Re: Switched Reluctance pancake EV drive-train

Quote:
Originally Posted by henrykeultjes View Post
Sorry folks, but I am not good at dealing with all those negatives.
Look, posting nonsense is negative.
"Considering that Switched Reluctance Motor/Generator (SRMG) are powered by DC, generate DC and that batteries can only be charged with DC"

What da faq does that how make sense bad?!? You *can* make it pulsed DC, but who cares?
Reply With Quote
  #10  
Old 04-20-2017, 08:37 PM
brian_ brian_ is offline
Member
 
Join Date: Feb 2017
Posts: 89
brian_ is on a distinguished road
Default Re: Switched Reluctance pancake EV drive-train

Quote:
Originally Posted by henrykeultjes View Post
Sorry folks, but I am not good at dealing with all those negatives.
Although the tone of the responses - including mine - was not very supportive, the real world has lots of negatives. Perhaps it's time to learn to deal with them... with knowledge and understanding.

Certainly posting a pile of text referring to diagrams and not providing the diagrams should be expected to result in some negativity.

Quote:
Originally Posted by henrykeultjes View Post
I am not a guy that went to Delft but I have ideas and a fairly good understanding of what might be possible and this post was submitted in that vein.
Henry, your post does not convey either original ideas or much understanding. Perhaps it's mostly a communication issue?

By the way, I'm not familiar with Delft. Do you mean the university in the Netherlands... then it's not surprising, although I'm sure it's a fine institution. I don't think anyone here cares as much about formal education as relevant ideas, effectively communicated.

Quote:
Originally Posted by henrykeultjes View Post
My email address is on the post and if someone is truly interested in pursuing this and make it work, email me because I will not be back on this site. Henry
Not a problem. If I am interested in SRMs, I'll read the existing texts and contact manufacturers of these products. I genuinely do not understand what idea was supposed to have been conveyed by the original post, and it must not be important if you're not willing to pursue it here.
Reply With Quote
Reply

Share or Bookmark this

Tags
ev drive-train, switched reluctance

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

 
Support DIY Electric Car
Sponsors

All times are GMT -6. The time now is 11:34 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Ad Management by RedTyger