DC Regen from practical and personal experience.

Open for any sort of non-technical discussion regarding EVs
Goombi
Senior Member
Posts: 532
Joined: Sun, 10 Aug 2008, 17:59
Real Name: Eugen
Location: Gympie

DC Regen from practical and personal experience.

Post by Goombi » Fri, 31 Dec 2010, 23:11


DC Regen from practical and personal experience.

Regen (charge/brake) was designed long time ago. It is mainly used for vehicles directly coupled to diffencial/ one speed ran by a motor from 0- 5000 rpm Mostly used for railway luggage trucks – forklifts Milk delivery wagons etc. decelerating from normal speed the regen was acting as a charger and therefore a brake.
For no Clutch –no gearbox - this was a very good combination of saving brakes and re-charging batteries at the same time.

To convert a normal gearbox car to regen/charger is not practical.
Conversions are expected to run from zero to 100Km/h in order to achieve this one needs a gearbox. Gearbox is also useful when going up a steep hill. Without gearbox average conversion will not be a success.

Have spent 3 month trying to incorporate REGEN to a ute with gearbox without result. What is happening with regen and gearbox? Most gearboxes are synchromesh and to change a gear should be easy. But not with Regen. When traveling and intending to change gear-removing foot from the accelerator at this instance the REGEN starts BRAKING/CHARGING. The Synchro is unable to place another gear in because it is engaged in reverse thrust. The gear is now locked in and the car is slowing down. The Regen is doing its job braking/ charging the batteries. To change the gear is almost impossible without doing some damage to gearbox. One had to keep going in one gear or stop and then change to higher gear. This is the miserable part.

Regen as such is a good servant for specific application , but not for gear boxed EV conversion.

Regen is a combination of commands from controller to motor that is also wound for charging. One can reduce the braking/charging speed from severe brake to very soft.

In conclusion, I will not recommend DC Regen with gearbox.
The manufacturer and me were working hard to solve the problem. Even using a time space between the gear changes proved problematic. Using Programmer to minimize the impact of Regen/Brake had no impact.

I am not surprised that some conversions are now made with 2 large motors in tandem to overcome the use of gearbox. And using one speed conversion with regen.
Some are also being used in AC/Regen systems.
I have never been able to obtain enough information about its final performance and gear changes from AEVA..
As a final attempt I have removed the DC Regen and replaces with DC Series system. It became a costly exercise and almost humiliating for not being able to solve the Regen Reasoning.

The ute runs as good as it should with DC Series motor and Controller the gear changes are performing smoothly and since I have been unable to check and compare the benefit of Regen the trouble was not worth the bother..

However I dare to say. If the EV conversion has no gearbox then I will assume the benefit of Regen/Charger will be beneficial for better charge and saving on brakes. Like so many Chinese El. Vehicles they have no gearboxes and are set in Differential ratio to reach max speed of 50 Km/h at 3000rpm. Some use AC and some DC Regen. These cars are supercharged Golf buggies. Slow from start and with the top speed unsatisfactory for Australian vehicle registration( therefore unable to register)I call them Paper Mache cars.

I like to hear from converters about their AC Regen experiences.
Eugen

Goombi
Senior Member
Posts: 532
Joined: Sun, 10 Aug 2008, 17:59
Real Name: Eugen
Location: Gympie

DC Regen from practical and personal experience.

Post by Goombi » Fri, 31 Dec 2010, 23:34

Goombi wrote:
DC Regen from practical and personal experience.

Regen (charge/brake) was designed long time ago. It is mainly used for vehicles directly coupled to diffencial/ one speed ran by a motor from 0- 5000 rpm Mostly used for railway luggage trucks – forklifts Milk delivery wagons etc. decelerating from normal speed the regen was acting as a charger and therefore a brake.
For no Clutch –no gearbox - this was a very good combination of saving brakes and re-charging batteries at the same time.

To convert a normal gearbox car to regen/charger is not practical.
Conversions are expected to run from zero to 100Km/h in order to achieve this one needs a gearbox. Gearbox is also useful when going up a steep hill. Without gearbox average conversion will not be a success.

Have spent 3 month trying to incorporate REGEN to a ute with gearbox without result. What is happening with regen and gearbox? Most gearboxes are synchromesh and to change a gear should be easy. But not with Regen. When traveling and intending to change gear-removing foot from the accelerator at this instance the REGEN starts BRAKING/CHARGING. The Synchro is unable to place another gear in because it is engaged in reverse thrust. The gear is now locked in and the car is slowing down. The Regen is doing its job braking/ charging the batteries. To change the gear is almost impossible without doing some damage to gearbox. One had to keep going in one gear or stop and then change to higher gear. This is the miserable part.

Regen as such is a good servant for specific application , but not for gear boxed EV conversion.

Regen is a combination of commands from controller to motor that is also wound for charging. One can reduce the braking/charging speed from severe brake to very soft.

In conclusion, I will not recommend DC Regen with gearbox.
The manufacturer and me were working hard to solve the problem. Even using a time space between the gear changes proved problematic. Using Programmer to minimize the impact of Regen/Brake had no impact.

I am not surprised that some conversions are now made with 2 large motors in tandem to overcome the use of gearbox. And using one speed conversion with regen.
Some are also being used in AC/Regen systems.
I have never been able to obtain enough information about its final performance and gear changes from AEVA..
As a final attempt I have removed the DC Regen and replaces with DC Series system. It became a costly exercise and almost humiliating for not being able to solve the Regen Reasoning.

The ute runs as good as it should with DC Series motor and Controller the gear changes are performing smoothly and since I have been unable to check and compare the benefit of Regen the trouble was not worth the bother..

However I dare to say. If the EV conversion has no gearbox then I will assume the benefit of Regen/Charger will be beneficial for better charge and saving on brakes. Like so many Chinese El. Vehicles they have no gearboxes and are set in Differential ratio to reach max speed of 50 Km/h at 3000rpm. Some use AC and some DC Regen. These cars are supercharged Golf buggies. Slow from start and with the top speed unsatisfactory for Australian vehicle registration( therefore unable to register)I call them Paper Mache cars.

I like to hear from converters about their AC Regen experiences.
Eugen


PS. The controller is fully occupied at all times when powering amps to motor and then resending Regen charge amps to batteries. Unless the controller has perfect cooling, the controller will get hot and or damage as happend to me. Constant passing of amps at time up to 400 amps can be detrimental to the controller.. With DC Series the power goes in and then stops at braking thus creating eventual cooling.

7circle
Senior Member
Posts: 540
Joined: Thu, 04 Feb 2010, 02:18
Real Name: Ken
Location: Melbourne

DC Regen from practical and personal experience.

Post by 7circle » Sat, 01 Jan 2011, 00:17

Controllers are just like servo positioning systems they can with some programing and perhaps two encoder inputs Motor and axle.

This would make the syncro still be capable of easing the gears together.

I hope to help with just this issue but with a WarpHV11 motor onto an AWD 5speed auto box with a Torque converter.

This is not a simple issue but can be done with standard motors that have regen on the motor. Its useful for gearing up and down.

7C

User avatar
Alex_Brooy
Noobie
Posts: 25
Joined: Tue, 10 Nov 2009, 06:29
Real Name: Alex
Location: Ukraine
Contact:

DC Regen from practical and personal experience.

Post by Alex_Brooy » Sat, 01 Jan 2011, 00:57

Hello, guys.
I just have finished the largest part of my regen braking experiments on series winded dc motor. I left 5-speed gearbox on my ev without change. But the clutch is removed. I rarely shift gears when running. I use 4-th gear most of the time.
I use regen when decelerating from 50-60km/h. But accelerator pedal doesn't affect on regenerative device. I use separate regulator to switch on the regen brake. I can use 2nd, 3rd or 4th gear when braking with regeneration. The gear choice depends on speed and necessary braking power.
You may watch the video I made
I apologize, if it forbidden to post references to other web-sites.

Moderator Edit: Make link "clickable". LInks to other websites are most welcome, as long as they are relevant to the discussion.
Last edited by antiscab on Sat, 01 Jan 2011, 13:01, edited 1 time in total.

User avatar
woody
Senior Member
Posts: 1715
Joined: Sat, 21 Jun 2008, 02:03
Real Name: Anthony Wood
Location: Mt Colah

DC Regen from practical and personal experience.

Post by woody » Sat, 01 Jan 2011, 05:09

I'd guess that peter's Holden combo has done the most regen-enabled EV miles (Zapi DC) and a gearbox too!. a4x4kiwi also has done a couple of thousand with AC regen direct drive.

Is it possible with the regen controller to have a switch on the clutch disable regen?

With an industrial programmable AC controller I would attempt to programme in the gear ratios and have it match the motor revs to the road speed and "next" gear. Working out the next gear the driver wants might be fun. (double clutch = down shift, single clutch = up shift?)

happy new decade all!
Planned EV: '63 Cortina using AC and LiFePO4 Battery Pack

Goombi
Senior Member
Posts: 532
Joined: Sun, 10 Aug 2008, 17:59
Real Name: Eugen
Location: Gympie

DC Regen from practical and personal experience.

Post by Goombi » Sat, 01 Jan 2011, 16:14

Hi Woody,It can be done and it will be done as it is done in heaven.

No one has yet developed a switch that would work well with a gearbox. No gearbox Is perfect one gear and only motor revs. I had tried everything with the help of zibo motor co. Nothing worked Either you have a Regen or you don't( with gear box). Synchronizing Regen Motor with a Regen controller has to be redesigned..
There is a way in theory only.. Is to use Regen wound motor and   Controller with a programmable delay of upo to 10 seconds to give the driver time to change gear without the reverse regen braking. There is only one such Regen controller on the market but will not work with Regen wound motors satisfactory..
I will stay by my research and information i have supplied to all Regen converters-- save money and go without a gearbox if you intend to do Regen.
Option: Go series. The benefit of Regen is not significant enough to compensate for the No Gearbox drive.Or the extra that is being charged to the batteries. As i mentioned before My experiment lasted 3 month and with more time Changing controllers motors adding stop resistors special capacitator delay switches etc and testing and zero final result

I like to hear from any one of you that has suceeded to make Regen work with gearbox even with a clutch.
The Regen controller works on instant switching and If you think my wife is going to drive a Regen car that does not work smoothly and efficently then you should not build one.
Save money go series and let the manufacturer catch up with some research. Us little ants cannot do it individually.

So far all i hear Regen needs synchronization's which is not available

AC regen has the same problem? please tell me...

Cheers Eugen

User avatar
Electrocycle
Senior Member
Posts: 985
Joined: Sun, 19 Oct 2008, 20:23
Real Name: Andrew
Location: Sydney
MSN: dumhed@dumhed.com
Contact:

DC Regen from practical and personal experience.

Post by Electrocycle » Sat, 01 Jan 2011, 17:14

I helped out with a conversion using one of your Zibo DC motors with regen, and the owner has found the same problem with changing gears.
We will be looking at making some sort of controller modification to help synchronise the motor revs on gearchange, but it will be a big job.

The other problem is that the sepex motor doesn't have anywhere near as wide a power band as a series motor, and the peak torque is much lower.
With a series motor the field and armature can be over driven on takeoff for much higher torque - but on the sepex the field is limited to what the controller can give it.

The result is much less torque at low revs, so you really need to use the gearbox - but with the regen controller it's very hard to change gears.

Maybe a small microcontoller monitoring the rpm and controlling the throttle signal is the best bet - but it's hard to have it predict when you're changing up or down!

I think the best solution would be to go to a series motor, but that's a very expensive way to fix it...
The Engine Whisperer - fixer of things

Goombi
Senior Member
Posts: 532
Joined: Sun, 10 Aug 2008, 17:59
Real Name: Eugen
Location: Gympie

DC Regen from practical and personal experience.

Post by Goombi » Sat, 01 Jan 2011, 17:31

Hi Electrocycle.. Now there is a honest answer. Obviously you have done your homework and experimentation. and came to the same conclusion as i did.
At one stage there was this REGENOMANIA in this chat and everyone tried or participate to save some energy back to batteries through REGEN
As you rightly said it will be expensive to change the Regen to series again Possibly 2k, but it will work. What other option is there?
Contact the new Agent for Zibo motors and see if he can help with replacement. talk to Graeme :suziauto@live.com.au If the Unit came through me or Graeme.

Cheers Eugen

Cheers Eugen


antiscab
Senior Member
Posts: 2490
Joined: Mon, 26 Nov 2007, 05:39
Real Name: Matthew Lacey
Location: Perth, WA

DC Regen from practical and personal experience.

Post by antiscab » Sat, 01 Jan 2011, 21:48

Goombi wrote:
Most gearboxes are synchromesh and to change a gear should be easy. But not with Regen. When traveling and intending to change gear-removing foot from the accelerator at this instance the REGEN starts BRAKING/CHARGING. The Synchro is unable to place another gear in because it is engaged in reverse thrust.


COrrect, you can't have negative motor torque while changing to a lower gear, just the same as you can't have positive motor torque while changing to a higher gear (unless you have and use a clutch).

does the controller support regen enable/disable?

The kelly controllers (all varieties) give you the option of 0-accelerator regen, or regen enabled by brake light, or regen controlled by additional pedal (0-5v input).

If the original controller does not support it, a kelly one will:
120v 600A
72V 800A

Just make sure braking at 0-accelerator is disabled, so at 0 throttle the motor is actually freewheeling.

Matt
Matt
2017 Renault zoe - 25'000km
2007 vectrix - 156'000km
1998 prius - needs Batt
1999 Prius - needs batt
2000 prius - has 200 x headway 38120 cells

User avatar
Electrocycle
Senior Member
Posts: 985
Joined: Sun, 19 Oct 2008, 20:23
Real Name: Andrew
Location: Sydney
MSN: dumhed@dumhed.com
Contact:

DC Regen from practical and personal experience.

Post by Electrocycle » Sun, 02 Jan 2011, 01:58

even with the regen sorted out I think it'd ideally need a clutch to make fast gear changes possible. The narrow power band of the motor means lots of shifting gears for usable performance.
The Engine Whisperer - fixer of things

User avatar
coulomb
Site Admin
Posts: 3780
Joined: Thu, 22 Jan 2009, 20:32
Real Name: Mike Van Emmerik
Location: Brisbane
Contact:

DC Regen from practical and personal experience.

Post by coulomb » Sun, 02 Jan 2011, 02:06

Matt,

why do you say this?
antiscab wrote: Just make sure braking at 0-accelerator is disabled, so at 0 throttle the motor is actually freewheeling.

Is zero throttle regen not your preference, or do you have some experience that says it's not a good idea?

I know it will need the ability to be disabled for wet roads and/or snow and ice (good idea to disable cruise control in these conditions too), but surely zero pedal regen would be the closest to ICE behaviour that there is, unless it's unexpectedly strong.

Edit: or is your advice for clutchless gearbox drivetrains?
Last edited by coulomb on Sat, 01 Jan 2011, 15:08, edited 1 time in total.
Nissan Leaf 2012 with new battery May 2019.
5650 W solar, 2xPIP-4048MS inverters, 16 kWh battery.
1.4 kW solar with 1.2 kW Latronics inverter and FIT.
160 W solar, 2.5 kWh 24 V battery for lights.
Patching PIP-4048/5048 inverter-chargers.

User avatar
Electrocycle
Senior Member
Posts: 985
Joined: Sun, 19 Oct 2008, 20:23
Real Name: Andrew
Location: Sydney
MSN: dumhed@dumhed.com
Contact:

DC Regen from practical and personal experience.

Post by Electrocycle » Sun, 02 Jan 2011, 02:08

edit: duplicate post
Last edited by Electrocycle on Sat, 01 Jan 2011, 15:10, edited 1 time in total.
The Engine Whisperer - fixer of things

Goombi
Senior Member
Posts: 532
Joined: Sun, 10 Aug 2008, 17:59
Real Name: Eugen
Location: Gympie

DC Regen from practical and personal experience.

Post by Goombi » Sun, 02 Jan 2011, 02:44

The only way to see if using Regen and clutch will help make shift gears is to try it out. Personally i have my doubts ..think what will happen when Regen kicks in and you going up in gear you let the clutch fast and you will rip the gearbox to pieces. Funny some clutches will hold tight when you least want them to.
Cheers Eugen

antiscab
Senior Member
Posts: 2490
Joined: Mon, 26 Nov 2007, 05:39
Real Name: Matthew Lacey
Location: Perth, WA

DC Regen from practical and personal experience.

Post by antiscab » Sun, 02 Jan 2011, 03:25

coulomb wrote: Matt,

why do you say this?
antiscab wrote: Just make sure braking at 0-accelerator is disabled, so at 0 throttle the motor is actually freewheeling.

Is zero throttle regen not your preference, or do you have some experience that says it's not a good idea?


you got it in the edit Image

otherwise the motor is fighting the syncros.

the motor is much stronger than the syncros.

while already in gear, it makes no difference.

Matt
Matt
2017 Renault zoe - 25'000km
2007 vectrix - 156'000km
1998 prius - needs Batt
1999 Prius - needs batt
2000 prius - has 200 x headway 38120 cells

7circle
Senior Member
Posts: 540
Joined: Thu, 04 Feb 2010, 02:18
Real Name: Ken
Location: Melbourne

DC Regen from practical and personal experience.

Post by 7circle » Sun, 02 Jan 2011, 03:56

I'm wondering how long it takes for a series DC motor to go from high load to no-load. This may take 100msec or more as the current is flowing through the free-wheeling diode.

If there is no active control by the controller to match speed the motor inductance may cause a delay in getting the motor to spin at zero torque (no-load output).

A controller with high and low side power transistors can use the motor inductance and back emf to create a dc/dc converter that steps up a low than battery potential back EMF to a recharging current into the batteries.

Many DC controllers only have one power transistor to supply PWM to the motor.
And some regen can be achieved by having a higher Back EMF in the motor by using gearing to spin the motor faster. This can give very rough regen like stabbing the brakes ( from theory).

The cost of Power semiconductors is not as bad as some think.
The case and control PCB is expansive to make adding an extra couple of channels of PWM adds very little to the controller cost.

The extra Power transistor and heat sinking is also not that more costly.
Especially when its all in the one Epoxy block.

When you back off the throttle you back off the current int he Firld and Armature. So the B-EMF will also fade as it it proportional to the Field Flux (Current when not saturated).

The expectation of getting regen from a simple series DC motor and Single Power transistor and free wheeling diode is ridiculous.

Going to field reversal with contactors is heading in the right direction.
But you still need the high and low side power transistors to get the Low RPM Step up DC/DC to function.

So we are back to discussing DC motors with high turn count Field Winding that only need a small current to produce the same field flux. because the cost of having a Reversing contactor that wil survive at over 200V with active switching for Regen will quickly kill the contact surfaces with arcing.

Perhaps the vacuum contactors may suit this better, or oil contactors to quench the arc with a bit of magnetic field pressure too that will move the electrons to one side that can be sacrificed. Sorry its getting complicated, but doesn't mean in can't be effective.

I like the Clutch switch idea. Or the Of throttle of zero regen to allow gear change, so when throttle off the controller tries to match no-load speed to wheel RPM. But this makes me concerned that off throttle will still keep the Controller supplying battery voltage to the motor. But I think it can be accepted if the diagnostic technician knows about it.

The reason regen is more valid now is that many Lithium cells accept recharge currents more efficiently. And they can then supply this fresh charge efficiently as well.

7C

Goombi
Senior Member
Posts: 532
Joined: Sun, 10 Aug 2008, 17:59
Real Name: Eugen
Location: Gympie

DC Regen from practical and personal experience.

Post by Goombi » Sun, 02 Jan 2011, 05:21

OK.. In 50 Km distance on a flat terrain how many stops do you intend to make. How much faster are you going to stop then you intend to? How many amps are you going to charge back-- what size motor how many batteries
From my experience and reading 144 volt 11 kw motor was charging back at 60 Km/h Regen 14 -8-4-0 amp the time was short to stop 20 seconds adjusted to low braking Regen.
The setting of Regen is unpredictable and not all settings are favoring the downhill some are steeper and some are gentle Preset Regen will stop faster on gentle downhill and you have to use accelerator to keep going. with steep downhill you still have to use brakes.
On a down hill where you do not use Regen you have a free run at no amp consumption your car will run up some speed and will only use small amount of AMPS to keep going on level ground.. With REGEN you cannot run up speed and therefore the amp charge is lost. In fact to maintain speed you have to use accelerator, therefore your Regen is useless.
all clear?
Have a nice 2011-- Regen free----------Eugen

Clutch. Take the weight of a clutch plate and its assembly All sitting on a 7/8 shaft the weight is at least 20 kg if your clutch plate as machined down The clutch assembly can run up to 5000rpm do you realize the amount of energy in the clutch? To make it spin with the motor will reduce the starting speed of the car On the other hand when slowing down with a clutch you will need to run REGEN at much higher settings or use brakes more often.

Then you are talking about Auto transmission.... another mistake--
Get your 8 circles in order..nothing personal



7circle
Senior Member
Posts: 540
Joined: Thu, 04 Feb 2010, 02:18
Real Name: Ken
Location: Melbourne

DC Regen from practical and personal experience.

Post by 7circle » Sun, 02 Jan 2011, 06:31

I'm all for a drive train that is motors on half-shafts to the wheels. So either two for rear or front axles.

I'm very interested in getting the most performance from a WarpHV11 motor using a 300V Battery pack maybe a bit higher.

Losses in a torque converter are an issue the project TC is signal controlled lockup. This allows for torque multiplying at very low revs when taking off.
As there is a slip from motor side to gearbox side the transmission fluid acts like a gear ratio and increase the torque seen on the gear box side. It is lossey in power terms but does increase torque.
- If I'm wrong with this please advise.

Interesting comments Goombi, the setup sounds quite jerky. I was wondering if you have used setup with a DC series motor with a field reverse contactor set and a controller with high and low side power transistors and back to pack diodes.

Wish you great 2011 full of new experiences.. Image

7C

User avatar
acmotor
Senior Member
Posts: 3603
Joined: Thu, 26 Apr 2007, 03:30
Real Name: Tuarn
Location: Perth,Australia

DC Regen from practical and personal experience.

Post by acmotor » Sun, 02 Jan 2011, 06:46

Keep in mind that just because a paricular regen system (DC,AC,gearbox,clutch,drect) may not yet be ironned out (or may never be) that I believe that functional, efficient and transparent to the driver regen is very viable and in fact essential to the future of EVs and motoring in general.
That is, don't confuse just how good regen can be with the difficulties of some implementations.

Goombi, your advice and experience is very useful and on the money. Regen suits direct drive, at least in terms of simple implementation. I would just add IMHO.... regen also suits AC systems.     Image
iMiEV MY12     110,230km in pure Electric and loving it !

7circle
Senior Member
Posts: 540
Joined: Thu, 04 Feb 2010, 02:18
Real Name: Ken
Location: Melbourne

DC Regen from practical and personal experience.

Post by 7circle » Sun, 02 Jan 2011, 07:43

I am very concerned about losses in gears at high torques.

Getting power back through a diff with hypoid gears (or whatever its called gearing) to me appears very lossy. I have spent many hours trying to get tested info on this. I need a IEEE subscription.

That's why I think front wheel axle connection is needed. And at least Tranverse motor mounting like most FWD cars have.

User avatar
Alex_Brooy
Noobie
Posts: 25
Joined: Tue, 10 Nov 2009, 06:29
Real Name: Alex
Location: Ukraine
Contact:

DC Regen from practical and personal experience.

Post by Alex_Brooy » Sun, 02 Jan 2011, 10:53

...From my experience and reading 144 volt 11 kw motor was charging back at 60 Km/h Regen 14 -8-4-0 amp the time was short to stop 20 seconds adjusted to low braking Regen.
The setting of Regen is unpredictable ...


a few words about my ev, and particular regen mode:
weight 820 kg
speed 60km/h
downhill distance 0.600 km, 15%
gear - 4th
system voltage 110V (32 pcs TSLFP90AHA)
series winded DC motor, nominal 7.2kW 72V
Field resistance - 10 mOhm
My "recuperator" develops about 200A in Filed winding.
Back current into the battery at regen - 50..70A.
If vehicle speed decreases below 40 km\h, I need to shift to 3rd gear.
It is very predictable due to resistor regulator. Watch the video, you'll see how I regulate the regen power.

...The expectation of getting regen from a simple series DC motor and Single Power transistor and free wheeling diode is ridiculous.

Well, may be it is ridiculous, but it works.
If you mean my schematic, the transistor in not one - there are 7 powerful MOSFET transistors in parallel with special driving. Free-wheeling diode is used to avoid Igen flow through transistor's internal diode.
Image
You tell about high turn motor Field (like shunt wounded motors have). But you don't tell about Amps and turns. They really play the main role. I mean that it doesn't matter if you use 1 turn Field at 200Amp or 200turns Field at 1 Amp.
If you do not believe me, you can test the principle of my regen device with series motor. Just connect 6V battery through manual powerful contactor. Make the motor Armature spin about 3000 rmp, depress accl.pedal and switch on the add-on contactor. You even don't free-wheeling diode to get regen. The back current will flow through the Field. Of course, you have to use series dc motor.
Begin to check it from low speeds. At some speed you will see that motor is generating back EMF into the battery.

7circle
Senior Member
Posts: 540
Joined: Thu, 04 Feb 2010, 02:18
Real Name: Ken
Location: Melbourne

DC Regen from practical and personal experience.

Post by 7circle » Sun, 02 Jan 2011, 13:59

Hi Alex
I had a look at your blog/forum. Very interesting. I'm thinking along very similar lines.
I was looking into this approach for reverse capability without contactors.
...See Ways to reverse Series DC Motor -100% FWD 30% RVRS -Posted: 2010 October 14 at 3:31pm
Image


In your video, are you mesuring the battery side current?
Do you see much variation in the Battery terminal voltage from discharge to charge at 10Amps charge current.

This is great description of what's happening.

Can you measure the voltage and current drawn by the "recuperator"?

Does the whole system inthe car run off the main battery pack.
Sometimes people forget to look at all the power sources.

Thanks for sharing with us Alex.

Cheers

Ken


User avatar
coulomb
Site Admin
Posts: 3780
Joined: Thu, 22 Jan 2009, 20:32
Real Name: Mike Van Emmerik
Location: Brisbane
Contact:

DC Regen from practical and personal experience.

Post by coulomb » Sun, 02 Jan 2011, 14:33

Alex_Brooy wrote: Watch the video, you'll see how I regulate the regen power.

Just so people can access Alex's video easily:



I would note that Alex's ammeter is offset, so when the scale reads 50 A, the current is actually zero. So rather than a 0-300 A meter, he actually has a -50 A to +250 A meter; it's on the battery side. Each graduation is 10 A. When he shows the recuperator drawing power, the meter moves from 50 A indicated (0 actual) to 60 A (10 A actual). I point that out only because it wasn't clear to me the first time I saw it.

It seems to me that compound wound motors (but with the shunt part of the field available on separate terminals) might be more suitable for this. I see that Kostov make some compound wound motors, but they only go to about 10 kW, and the shunt field connections are not available on separate terminals. Then again, these motors would be designed to use the shunt part of the field all the time, not just when using regen. Also, it may not be an effective use of the space needed for the shunt field windings. So Alex's solution may be best after all.

Alex: well done! As you can see, you've achieved (at least in proof of concept form) what a lot of people have been attempting for a long time!   Image
Nissan Leaf 2012 with new battery May 2019.
5650 W solar, 2xPIP-4048MS inverters, 16 kWh battery.
1.4 kW solar with 1.2 kW Latronics inverter and FIT.
160 W solar, 2.5 kWh 24 V battery for lights.
Patching PIP-4048/5048 inverter-chargers.

User avatar
coulomb
Site Admin
Posts: 3780
Joined: Thu, 22 Jan 2009, 20:32
Real Name: Mike Van Emmerik
Location: Brisbane
Contact:

DC Regen from practical and personal experience.

Post by coulomb » Sun, 02 Jan 2011, 14:52

7circle wrote: I'm thinking along very similar lines.
I was looking into this approach for reverse capability without contactors.
Yes, I think that this could work, although depending on the size of the regen controller, reverse torque might be a bit weak. People think of reverse as only needing low torque for car parks, but remember that you sometimes might have to reverse out of a roadside park on a steep downwards hill. For that, you might need close to full motor amps in reverse. That would be asking a lot of the regen controller (twice close to full motor amps!) Reverse speed will always be low, so the power will be low, but the current needed could be very high.
Can you measure the voltage and current drawn by the "recuperator"?
In his video, he shows that his recuperator's controller draws about 10 A from the pack, and this is enough for about 50 A (overall, so 60 A through the armature) of regen. In other words, the motor is generating up to about 60 A, but about 10 A of that goes back through the regen controller to keep the field polarity and amplitude correct. So overall, about 50 A goes back into the pack.

[ Edit: oops! I've just realised that field current required for reversing the motor would be in the opposite direction to what is needed for regen. So you couldn't combine the contactorless reversing with regen, without needing a reversing contactor! Image

The good news is that you could put the reversing contactor on the primary of the transformer, where it would switch higher voltage (about pack voltage) at much lower current (about 10 A in Alex's setup), so this would still be a win (you could use a much smaller reversing contactor, and it should last a lot longer than if it had to switch traction current). ]
Last edited by coulomb on Sun, 02 Jan 2011, 03:57, edited 1 time in total.
Nissan Leaf 2012 with new battery May 2019.
5650 W solar, 2xPIP-4048MS inverters, 16 kWh battery.
1.4 kW solar with 1.2 kW Latronics inverter and FIT.
160 W solar, 2.5 kWh 24 V battery for lights.
Patching PIP-4048/5048 inverter-chargers.

Goombi
Senior Member
Posts: 532
Joined: Sun, 10 Aug 2008, 17:59
Real Name: Eugen
Location: Gympie

DC Regen from practical and personal experience.

Post by Goombi » Sun, 02 Jan 2011, 18:15

50 amp going into a pack from 72 volt system is a nonsense.
reliable Idiot proof REGEN is not available for EV with gearbox even with a clutch.How many of you are sitting on a Regen system still trying to work out why you didn't go series. If Regen was simple to use just like a normal car then i will build one-- but its not. Too many things to go wrong plus additional overheating.. All what I heard so far are pure theories.
AC motor is not telling much --how he managed his Regen I wouldn't tell either.
Solution to Regen is a patented discovery and can be worth $$$$$

User avatar
Alex_Brooy
Noobie
Posts: 25
Joined: Tue, 10 Nov 2009, 06:29
Real Name: Alex
Location: Ukraine
Contact:

DC Regen from practical and personal experience.

Post by Alex_Brooy » Mon, 03 Jan 2011, 03:24

Goombi wrote: 50 amp going into a pack from 72 volt system is a nonsense.
reliable Idiot proof REGEN is not available for EV with gearbox even with a clutch.How many of you are sitting on a Regen system still trying to work out why you didn't go series. If Regen was simple to use just like a normal car then i will build one-- but its not. Too many things to go wrong plus additional overheating.. All what I heard so far are pure theories.
AC motor is not telling much --how he managed his Regen I wouldn't tell either.
Solution to Regen is a patented discovery and can be worth $$$$$

Dear Goombi,
what EV do use everyday?
If you or your friends have series winded motor with 72..140V system, you can check the principle I use. Read the end of my article - http://electricmobile.ru/regenarative-b ... -dc-motor/
The regen will not work very efficient, but this schematic allows to check it out.

Post Reply