IsSuitable motor for Land Rover Series 2A conversion

12403 Views 21 Replies 6 Participants Last post by jetpax, Aug 3, 2017

prensel

Discussion Starter · Apr 29, 2017

Hi,

I have plans to convert a diesel Land Rover Series 2A 109 to an EV.
A possible motor I have available for this project is either a 96V Ziehl-Abegg VFD160 or an Azure Dynamics AC23

The specs of the VFD160 motor are:
P = 15kW
n - 1470rpm
Mn - 95Nm
Mmax = 210Nm
In = 154A
Imax = 370A

Will this motor be powerfull enough for the LR ?
My first thoughts are to mount the VFD motor directly on the transferbox and leave out the gearbox at all or mount the AC-23 on the original.

For the controller/inverter I have the option for a Zapi AC-4/96V or an UMAX445 for the AC-23 on 310V

I have read about other LR conversion based on an AC-50. Looking at the specs the VFD160 would outperform the AC-50. But maybe the AC-23 is capable enough for this also ?

What would be the best choice ?

Thanks,

Paul

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madderscience

· #2 · Apr 29, 2017 (Edited)

As a series owner (IIA 88") I know a bit about rovers.

First of all, assuming your truck has its original, unmodified 2.25 diesel its specs are about 60 horsepower and 100 ft-lbs of torque. That is about 50kw (I was wrong when I said 80kw originally) and 140nm. These are peak power numbers. this is also when it was new.

your proposed motor has a 15kw continuous power rating and max torque of 210nm. that might be a bit on the small side, but the bigger question is what the peak power rating of your inverter / VFD is. the 2.25 diesels are considered underpowered by todays standards so I'm assuming you don't want to go any less than what it has now. If the base speed of your proposed motor is 1500rpm that is pretty low too. probably comparable to the torque curve of the diesel, but you can do better.

I'd be looking for a system that can continuously output 20-30kw if possible, and has a peak of at least 100kw. Torque more like 300nm would be better as well. Siemens motors, Azure/Solectria systems and systems based on the remy HVH250 motor cartridge would work well.

I have an older solectria/azure system rated at about 100kw, and has peak torque of about 250nm. It would be powerful enough if the transmission were retained to power my series and perform better than the original gas engine, though I would definitely want to retain the transmission.

Good Luck.

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prensel

Discussion Starter · #3 · Apr 29, 2017 (Edited)

60HP is 44kW

The planned inverter to use with the Ziehl motor is the Zapi AC-4, 20kW, 96V/550Arms.

I assume it is a low RPM/high torque motor hence the plan for mounting it directly on the transfer box.
The Ziehl motor alone just weighs over 100kg so thats why I want to get rid of the original gearbox also.

prensel

Discussion Starter · #4 · Apr 29, 2017

I noticed your SCION build and the use of the UMOC445F.

Since I also have an UMOC445F inverter laying around would that be the better option using it for the LR project instead of the 96V system ?
The motor I have for the UMOC is 'just' an AC-23, probably too small.
What I like about the UMOC is that it runs on 310V and I have two 310V/24kWh battery packs which would fit perfectly when going that route of setup.

brian_

· #5 · Apr 29, 2017 (Edited)

prensel said:
The specs of the VFD160 motor are:
P = 15kW
n - 1470rpm
Mn - 95Nm
Mmax = 210Nm
In = 154A
Imax = 370A

Checking if I understand the symbols correctly:

P: Power
n: speed (normal or best or peak-power speed?)
Mn: torque ("moment")... at normal speed?
Mmax: maximum torque ("moment")... at what speed?
In: current... normal current? at normal speed (1470 rpm)?
Imax: maximum current... at what speed?

I didn't see an indication of actual voltage at any of these conditions, so I assume these values are for 96 volt input.

If the "Mn" value is at "n" speed, that's 14.6 kW, which is consistent with the claimed output power. How does a Land Rover perform on 20 horsepower? I would think that would be inadequate to maintain highway speed, let alone accelerate.

At 1470 rpm, 154 amps of current would imply 95 volts at perfect efficiency, so there's something a little fishy about the values - motors are not 99% efficient under any conditions. Maybe the test voltage is higher and the 96 volts is "nominal".

The maximum values are lot higher, to handle brief acceleration. If the peaks are at the same speed, they indicate 32 kW output and at least 35 kW input (a reasonable relationship). Is 43 horsepower at peak (and less at every other speed) enough for acceleration? As already noted, this is less than the already low-powered Series IIA had originally:

4-cylinder 90.47 x 88.9mm 2286cc CR 23:1
62 bhp (net) at 4000rpm
Max. torque 103 lb/ft at 1800rpm

(from http://www.cleveland.co.jp/specs/old.html)
That's 46 kW and 140 Nm.

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brian_

· #6 · Apr 29, 2017

prensel said:
My first thoughts are to mount the VFD motor directly on the transferbox and leave out the gearbox at all

prensel said:
I assume it is a low RPM/high torque motor hence the plan for mounting it directly on the transfer box.
The Ziehl motor alone just weighs over 100kg so thats why I want to get rid of the original gearbox also.

The torque may be okay compared to the original engine in top gear, but is nowhere near what would come out of the transmission in a lower gear.

Assuming that the transfer box is a two-speed, the lower range could be used as a low gear, but

I don't know if it can reasonably be shifted while driving, and
I don't know if low range can be used in two-wheel drive.

madderscience

· #7 · Apr 29, 2017

I corrected my earlier KW math. sorry.

the umoc445f came programmed for a couple of different motor types. Mine is an AC55. There are a variety of setting you can adjust on it with just a terminal emulator program and any PC with a serial port or USB emulator. I don't know however if you can program it for a totally different motor type, as there are other settings and different firmware versions.

However as I mentioned previously, an AC55 with UMOC445f would be suitable in a series rover, if the transmisson were retained. I'd estimate top speed would be 65mph with a 320v nominal battery, but in lower gears it would be pretty torquey as that motor has about double the torque of the original 2.25.

FWIW here is a dump of the UMOC configuration settings from my inverter. I've tweaked and tuned since I took this, but these are working setings for a UMOC with an AC55.

0 Max Bat. Volts:250.0 V vs 364.0
1 Max Fwd Speed : 8.0 kRPM vs 12.0
2 Min Bat. Volts:160.0 V vs 234.0
3 Brake Min Spd.: 0.2 kRPM
4 Max Pwr Mtr I :290.0 Apk vs 350.0
5 Brake Lt Curr.: 90.0 Apk vs 50.0
6 Max Reg Mtr I :150.0 Apk vs 170.0
7 Pedal MaxBrake: 0.10
8 Power Svr. Min: 60 A vs 20
9 Pedal Brake : 0.35 vs 0.30
10 Power Svr. Max: 180 A
11 Pedal Accel : 0.50 vs 0.40
12 Regen Bat Max : 60 A
13 Pedal MaxAccel: 0.76 vs 0.85
14 Shaft Dir. : 1 vs -1
15 Speed Limiting: 1.0 kRPM vs 3.0
16 Bat. Limiting : 20.0 V vs 30.0
17 Brake Limiting: 1.0 kRPM
18 Vel. Damp tau : 0.10 sec
19 Slip constant : 0.40 Hz vs 0.80
20 Acc. Damp tau : 0.03 sec
21 Maximum id : 65.0 A vs 80.0
22 Damp viscocity: 0.00 NMs/r vs 0.50
23 Max Sync. Ind.:11.70 mH vs 2.40
24 Configuration#: 0
25 Max Leak. Ind.: 1.30 mH vs 0.30
26 Torque Slew : 2000
27 50% Ind. Cur. : 130 A vs 150
28 Eff IGBT Res : 62.0 mOhm vs 62.0
29 Encoder pulses: 60 vs 48
30 Vbatt Decay : 0.20 vs 0.10
31 Speed Decay : 0.10
32 V utilization : 1.00
33 Crossover Comp: 10 vs 5

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madderscience

· #8 · Apr 29, 2017 (Edited)

Regarding the series transfer case, they come in "suffix A" through "suffix D" (spanning the years from series II in the late 50's through the mid 80's) Gear ratios vary a bit by the year but they are all the same basic design:

High gear ratio is about 1.15:1
Low gear ratio is about 3:1 but can vary

NO shift on the fly

4wd Hi range can be engaged on the fly (assuming you don't have freewheeling hubs on the "open" position). Low range is 4wd only.

While the main gearbox has the typical british transmission issues, the series transfer cases are pretty tough; for example being known to be able to handle small block V8 power. IIRC the "Best" suffix is considered the B suffix.

you CAN add an overdrive unit (which attaches to the PTO output on the back of the transfer case) and get 2 speeds with shift on the fly that way. I have a newer wise owl overdrive (based on the epicyclic gear out of a chevrolet automatic transmission) which works pretty well, but despite being shift on the fly it hasn't ever shifted very easily)

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brian_

· #9 · Apr 30, 2017

Great info

This:

madderscience said:
... you CAN add an overdrive unit (which attaches to the PTO output on the back of the transfer case) and get 2 speeds with shift on the fly that way.

...is clever, and nets a setup with two ratios, but they are high and too high.

prensel

Discussion Starter · #10 · Apr 30, 2017

The voltage of 96V and the other values are printed on the Ziehl motor plate, here's a picture of that in attachement. I couldnt find any other specs (yet) from the Ziehl website.

One thing i dont understand is that this motor is so huge and heavy but still seems to put out these 'low' power figures. These motors are used in elevators and the VFD160 type is one of the biggest they have.
Compared to the AC-23 and Remy HVH250 its almost quadriple the size and it weighs >100kg..

you CAN add an overdrive unit (which attaches to the PTO output on the back of the transfer case)

I've noticed this in the Haynes manual, now this could be interesting.
What if i would just ADD the/a motor to this PTO output and leave the diesel engine in tact thus creating a hybrid vehicle ??

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madderscience

· #11 · Apr 30, 2017 (Edited)

Most AC motors designed for stationary use are very heavy, and yes probably substantially under-rated vs. what they could do, at least on intermittent basis.

And looking at the label on that one, its actually a 50hz nominal frequency motor. That means its going to be about 20% heavier than a 60hz motor of otherwise similar specs. (more iron needed)

If the 2 speeds available with an overdrive are too high, then it should be possible to fit higher gear ratio ring and pinion sets to increase the overall ratio a bit. Also, while quite rare there were some UNDERdrives made by fairey. but the fairey under/overdrives would wear out and fail after 40-50k miles. Finally, assuming you aren't planning hard core offroading, you could fit somewhat smaller diameter tires to change your effective drive ratio.

Land rover themselves tried the genset/motor-on-PTO ouptut approach in the 60's with a couple mobile welder / hybrid prototypes. I used to have an old edition of a land rover enthusiast magazine that had an article about them. Of course the usual DIY hybrid caveats come in to play - you have to carry 2 full drivetrains, no weight offset in the conversion by removing ICE components (a big offset in the case of the weight of a 2.25) and you have to find a way to make the two halves work together efficiently enough to be a net benefit. Nobody has really achieved this in DIY land.

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prensel

Discussion Starter · #12 · Apr 30, 2017

Re: Suitable motor for Land Rover Series 2A conversion

Since nobody seems to have build a hybrid LR Series I assume this is not the best way to go for.

So to sum things up what would be the best option:

1: UMOC445 inverter with AC-23 motor connected on original or modified gearbox
2: Zapi AC-4 with the Ziehl motor connected directly on the transferbox without gearbox. Either on the gearbox side or on the PTO side.
3: Remy HVH250 with matching inverter connected on the gearbox
4: other motor with the UMOC445 inverter ?

I prefer using a higher voltage system (310V) because I can source 310V/24kWh batterypacks pretty cheap.

brian_

· #13 · May 1, 2017

prensel said:
The voltage of 96V and the other values are printed on the Ziehl motor plate, here's a picture of that in attachement. I couldnt find any other specs (yet) from the Ziehl website.

Thanks - that's informative.

madderscience said:
And looking at the label on that one, its actually a 50hz nominal frequency motor.

That's the first thing I noticed - not that it is 50 Hz rather than 60 Hz, because 50 Hz is normal for Germany, but that it's a 3-phase AC motor. It specifies that it is three-phase ("3~") and that it operates with a delta configuration of 68 volts. It even includes a power factor (of 0.88).

I don't know how to reconcile the "BATTERIESP. 96V DC" and 3-phase power specs; similarly, it has a speed specification of 1470 rpm, conflicting with the synchronous speed at 50 Hz for 3000 rpm. I suppose they could be saying that if run by a variable-frequency drive, the drive would need 96 V DC supply, but the speeds are still strange.

madderscience said:
... its actually a 50hz nominal frequency motor. That means its going to be about 20% heavier than a 60hz motor of otherwise similar specs. (more iron needed)

An AC motor at 50 Hz goes 5/6ths of speed of one at 60 Hz... so yes, to produce the same power it must produce 6/5ths of the torque, so it is about 20% heavier. I don't know that this matters when running at neither 50 Hz nor 60 Hz.

lastcyrol

· #14 · May 1, 2017

brian_ said:
...
similarly, it has a speed specification of 1470 rpm, conflicting with the synchronous speed at 50 Hz for 3000 rpm. I suppose they could be saying that if run by a variable-frequency drive, the drive would need 96 V DC supply, but the speeds are still strange.
...

3000rpm would be the speed of a two-pole synchronous motor at 50Hz. An asynchronous one will stay a little behind that speed.
1470rpm looks like the motor is a four-pole one (asynchronous, i.e. induction motor).

brian_

· #15 · May 1, 2017

lastcyrol said:
3000rpm would be the speed of a two-pole synchronous motor at 50Hz. An asynchronous one will stay a little behind that speed.
1470rpm looks like the motor is a four-pole one (asynchronous, i.e. induction motor).

Good catch - this makes perfect sense.

I don't know why I was thinking that it must be two-pole

but it's apparently not.

prensel

Discussion Starter · #16 · May 1, 2017

After reading more about differences between 'EV' and industrial motors I was wondering what would happen if I power this motor with a 144VDC input AC inverter instead of the recommended 96VDC ? Would that ruin the motor in the end ?
What would be the power and RPM numbers ?

Or can I use an even more powerfull inverter like 240VDC or 310VDC input ?

jhuebner

· #17 · May 1, 2017 (Edited)

If you increase the voltage you can maintain peak torque at higher speed thus increasing output power.

So increasing from 96V to 144V pushes base speed to 1470*144/96=2205rpm.

If I remember correctly power works out to 2*pi*Torque[Nm]*speed[1/s]
6.28*210*36.75=48kW

You *might* be able to push it to 310V but could run into inductance issues, i.e. you'd need rather impractically high PWM frequencies.

Good thing is, that more speed doesn't generate much more heat (only increased eddy losses - not significant)

Should it work peak power would come close to 6.28*210*4750/60=104kW

The industrial motor I use in my conversion is the typical form factor and weight (66kg) of a [email protected] motor but outputs 50kW without getting overly hot. That is with the cooling fan removed!

EDIT: just noticed 96Vdc is in delta. If you change it to star that would increase 50Hz DC input voltage to 166V (and lower currents accordingly). So now running with 310V DC voltage would work out to

Base speed: 1470*310/166=2745rpm.
Peak power: 6.28*210*2745/60=60kW

I wouldn't expect any inductance issue at that kind of increase.

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prensel

Discussion Starter · #18 · May 2, 2017

So re-wiring the motor from delta to star powered with a 310V pack would make it very capable of pushing the Land Rover at decent speed and with decent torque forward.
What inverter would be the best option for this ? UMOC, DMOC or an DIY inverter/AC Motor Inverter Kit ?

jhuebner

· #19 · May 2, 2017

Others must judge whether your final drive ratio is ok. What speed will the car be going at at motor base speed? You should arrive at 50-80 kph. Any more and you'll suffer from poor climb-ability.

All inverters do the same, produce the same amount of power and efficiency. DIY offers best customization because it's open source.

prensel

Discussion Starter · #20 · May 6, 2017

madderscience said:
I corrected my earlier KW math. sorry.

the umoc445f came programmed for a couple of different motor types. Mine is an AC55. There are a variety of setting you can adjust on it with just a terminal emulator program and any PC with a serial port or USB emulator. I don't know however if you can program it for a totally different motor type, as there are other settings and different firmware versions.

Which firmware do you have installed ?
Is there a way to transfer (download/upload) firmware from one inverter to the other ?

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