ABB motor and VFD selection

Post by **Richo** » Fri, 28 Aug 2009, 21:46

The 2-pole 7.5kW prob won't be as happy at 60mph cont as the 11kW 2-pole.

Get some prices and you can weigh up which is better.
Also check the length you can fit in the engine bay as this usu limits what you can put in.

Post by **woody** » Fri, 28 Aug 2009, 23:48

I've done some numbers.

The servomotors are ACIM anyway

In my car (similar to your Ghia - '63 Ford Cortina)
52 Greensavers, 55kW controller
Through a gearbox (MX-5, but won't make much difference)
Weight 1200kg.
CM1.7:
0-100 11s
400M 17s

Compare ABB 131-008 HSE
0-100 6.7s
400M 14.2 s

The 131-008-HSE is my pick for you. 22kW 2 pole ACIM.

How much are these servo motors?

We are quoted here AU$2K for the 131-008HSE, AU$1K for the 132-316HSE.
Also about $1.5K for a 1024 pulse encoder.

cheers,
Woody

Post by **Richo** » Sat, 29 Aug 2009, 00:02

woody wrote:The 131-008-HSE is my pick for you. 22kW 2 pole ACIM.

22kW x 1.82 x 3.8 = 152kW peak @ 5300RPM 95kg

Hmmm well I guess he could always put in a bigger controller later for it

Post by **woody** » Sat, 29 Aug 2009, 00:34

You've got to be limited somewhere

I think the greensavers is going to be it - which gives a nice flat top to the power curve. No point getting a motor which only reaches the controller peak.

Another point is that the servo motors don't mention efficiency - which kinda makes me think it's not that good.

Ghia Guy - ask Mr ABB what's wrong with our plan - invite them on the forum for some witty banter with us

Post by **coulomb** » Sat, 29 Aug 2009, 07:09

Richo wrote: 22kW x 1.82 x 3.8 = 152kW peak @ 5300RPM 95kg

What's the 1.82 figure? Does the S option give more than sqrt(3) overvoltaging?

Edit: oh, I guess it's 600 VDC gives say 420 VAC, which is about 1.82 times 230 VAC. So part of that is that we typically supply the controller with slightly "above average" "mains voltage". Close?

Post by **e-ghia** » Mon, 31 Aug 2009, 12:14

Awesome input as always. Thanks woody, Richo, et al.

Richo wrote:Also check the length you can fit in the engine bay as this usu limits what you can put in.

Yes, length is a big issue for us. We have about 550mm max space available, and this includes shaft length. Even if we went with the CM1.7, we would have to trim about 50mm off of the 110mm shaft to fit it.

woody wrote:In my car (similar to your Ghia - '63 Ford Cortina)
52 Greensavers, 55kW controller
Through a gearbox (MX-5, but won't make much difference)
Weight 1200kg.
CM1.7:
0-100 11s
400M 17s

Compare ABB 131-008 HSE
0-100 6.7s
400M 14.2 s

Thanks for the numbers, woody. I have similar power and energy consumption models based on real commute data, but I've not calculated performance like yours. Is the 1200kg the projected final weight? Does it include a passenger? Our pre-conversion weight is 840kg (with ICE). For the power/energy models, I assume 1360kg to be safe. This would be on the heavy side say with two passengers to give more of a worst case.

woody wrote:The servomotors are ACIM anyway

How much are these servo motors?

You're absolutely right, woody. They are ACIM, but a little different breed. I was wondering if anyone had any real experience or first-hand knowledge of these. The rough price quote we got was $2200-2600 USD.

woody wrote: You've got to be limited somewhere I think the greensavers is going to be it - which gives a nice flat top to the power curve. No point getting a motor which only reaches the controller peak.

Yes, right again. Our hope is that the bottleneck occurs at the batteries (rather than the motor or VFD) as they will be replaced/upgraded down the road.

woody wrote:Another point is that the servo motors don't mention efficiency - which kinda makes me think it's not that good.

Ghia Guy - ask Mr ABB what's wrong with our plan - invite them on the forum for some witty banter with us

CM1.7 - 92.8% eff. @ 4000 rpm, 21.0kW & 50.1 Nm
I would give just about anything to the ABB folks in here, and let you all go at it. Frankly, all of you understand the application better than they do (EVs, that is.) Now, we get to the meat... The names have been changed to protect the innocent.

Mr. ABB guy #1 wrote:This is the wrong motor for this application...

Please take a look at our HDP product offering - I spoke with one of our factory experts from Italy (Mr ABB guy #2) who is here on contract. He provided the catalogue for our HDP product offering.

ABB guy #1 didn't give much of a reason, but wasn't terribly helpful throughout the process. I suspect he's more of a sales guy now, and has forgotten some of his engineering background.

Mr. ABB guy #3 wrote:Mr. ABB guy #1 and Mr. ABB guy #2 are confident that you will destroy your original selected motor due to overheating, which is why they suggested the servo motor family. I spoke with Mr. ABB guy #2 about the motor selections.

Mr. ABB guy #3 was great and really helpful throughout, but he's a drive expert and admits that he's not up to speed on motors, pun intended. I think it through them off when we said that we were going to send 400V to the 240V delta, even though we thoroughly explained the need for additional cooling, etc.

So, here's what I've surmised. Don't misunderstand, I totally believe that ACIMs will absolutely work in an EV (there is proof of that in these forums.

), and the people to whom we've spoken at ABB are mistaken and misunderstand the application.
But, perhaps a servomotor is slightly better suited: big forced cooling fan, built-in encoder, smaller moment of inertia, fat torque in the field-weakening range, etc. From what I can tell, these motors are designed for dynamic operation (like CNC machines, extruders) and frequent acceleration, deceleration, and dynamic loads. They have high overload capacity and still give max torque past 3000 rpm.

I'm NO motor expert (complete novice, in fact), but my feeling is that ACIMs are capable of being dynamic and can handle overloading while industrial servomotors like these are designed for it. I think that the prevailing argument here is $$$, but I should say that we are more concerned with performance and less concerned about cost.

Any thoughts? I'll put on my fire-retardant suit.

Post by **e-ghia** » Mon, 31 Aug 2009, 13:46

By the way, all of the motor suggestions are awesome. When we spoke to ABB, we specifically asked about the 131-003 and 131-316 of the IPM line of motors (EFF1).

Also, here's some info about the original ICE: Tmax = 105Nm @ 2800 rpm (or 31kW). Pmax = 39.5kW @ 4200 rpm (or 90Nm). So we estimate that with the increased mass that we want about 40-50% higher figures: Tmax ~150Nm and Pmax ~56kW. Down the road, we upgrade to LiFePO4 (lose some weight), and we see a significant increase in performance. That's the concept, at least.

So, I mentioned earlier that we are looking into some servomotors at a company called SEW Eurodrive. (Student friendly = big discount). You can find the documentation here.

We like the CFM112L (without the gearmotor accessory), and we're talking to one of their engineers later this week. Also, I should mention that ABB has offered a free firmware upgrade to our VFD to handle any servomotors. The motor can be ordered with an additional fan which boosts the nominal torque by 45%. With the fan, the nominal torque is about 58Nm @ 3000 rpm = 18.3kW, and it has a max dynamic torque of 157.5Nm. Also, it weighs only 40kg.

Post by **Johny** » Mon, 31 Aug 2009, 15:53

SEW Eurodrive make many of their motors with copper rotors which also increases efficiency.
e-ghia, are you still going with the gearbox?

Post by **woody** » Mon, 31 Aug 2009, 16:20

Johny wrote: e-ghia, are you still going with the gearbox?

Bit tricky not to with a VW (Karman Ghia has VW Bettle Mechanicals):

http://www.volksworld.com/imageBank/j/j ... op_005.jpg

That big hole in the gearbox is where the diff goes, the motor mounts at the rear (top left of this picci)

Post by **e-ghia** » Mon, 31 Aug 2009, 17:38

Hi Johny & woody,

Yes, absolutely keeping the gearbox as it contains the differential. Pulled it out a couple weeks ago for upcoming installation.
Right again woody!

I hope to get some torque curves from the SEW engineer, and I'll share them here. But don't let that stop the discussion...

Post by **woody** » Mon, 31 Aug 2009, 18:14

e-ghia wrote: Awesome input as always. Thanks woody, Richo, et al.

It's a pleasure

e-ghia wrote: Is the 1200kg the projected final weight?

If I was going to use Greensavers, yes. I'll do future calcs for you with 1360. Do you have a Cd / Cx and frontal area for the Ghia?

e-ghia wrote: The rough price quote we got was $2200-2600 USD.

Not bad considering the encoder included.

woody wrote: You've got to be limited somewhere I think the greensavers is going to be it - which gives a nice flat top to the power curve. No point getting a motor which only reaches the controller peak.

Yes, right again. Our hope is that the bottleneck occurs at the batteries (rather than the motor or VFD) as they will be replaced/upgraded down the road.

e-ghia wrote: CM1.7 - 92.8% eff. @ 4000 rpm, 21.0kW & 50.1 Nm

Good - my cynicism was wrong

e-ghia wrote:
Mr. ABB guy #1 wrote:This is the wrong motor for this application...

Please take a look at our HDP product offering - I spoke with one of our factory experts from Italy (Mr ABB guy #2) who is here on contract. He provided the catalogue for our HDP product offering.
ABB guy #1 didn't give much of a reason, but wasn't terribly helpful throughout the process. I suspect he's more of a sales guy now, and has forgotten some of his engineering background.

Mr. ABB guy #3 wrote:Mr. ABB guy #1 and Mr. ABB guy #2 are confident that you will destroy your original selected motor due to overheating, which is why they suggested the servo motor family. I spoke with Mr. ABB guy #2 about the motor selections.
Mr. ABB guy #3 was great and really helpful throughout, but he's a drive expert and admits that he's not up to speed on motors, pun intended. I think it through them off when we said that we were going to send 400V to the 240V delta, even though we thoroughly explained the need for additional cooling, etc.

The ABB guys probably aren't aware the continuous power requirements for normal commuting are 10-15kW, rather than the 50-250kW (peak) which cars are advertised with.

Post by **Richo** » Tue, 01 Sep 2009, 04:19

Richo wrote: 22kW x 1.82 x 3.8 = 152kW peak @ 5300RPM 95kg

coulomb wrote:
What's the 1.82 figure? Does the S option give more than sqrt(3) overvoltaging?

Edit: oh, I guess it's 600 VDC gives say 420 VAC, which is about 1.82 times 230 VAC. So part of that is that we typically supply the controller with slightly "above average" "mains voltage". Close?

Ah true 132 frame would be sqrt(3)-> 145kW

When I had mine rewound 220V was the easier (1.82).
For 160 frame and bigger they aren't exactly clear on the precise voltage for the "S" option.
Maybe they should just say 230+/-5%

Under full load I hope to keep it at or just above 400Vac.

Post by **Richo** » Tue, 01 Sep 2009, 05:59

If cost does become an issue the US ebay seem to have some motors worth a look every now and then for around USD$500.
11kW 2-pole 132-frame Italian motor

Edit: Added price

Post by **e-ghia** » Sat, 19 Sep 2009, 17:58

Well, we went with a servomotor after all. We met with an engineer at SEW a couple weeks ago, and we came home with this.

It's the CFM112L rated at 157.5 Nm of max torque which the engineers there tell me can be sustained for up to 10 minutes at a time. The rated speed is 4500 RPM, so using a gearbox it should have similar characteristics to that of the ICE (except we'll probably never use 1st gear).

That thing on the end is a resolver with a built-in thin-film temperature sensor. The temperature sensor should will give us an indication as to whether or we'll need to install a cooling fan with respect to our usage.

We have no experience programming an ABB drive

(but we have a little experience in studying control systems and programming microcontrollers). I assume that the resolver will allow us to use a 'closed loop' program. Although we've never really had direct experience with that.

Here's the 55kW drive that we'll use for this. Any tips?

Share your thoughts and insights. All of you have been so helpful thus far.

Post by **antiscab** » Sun, 20 Sep 2009, 07:16

both drive and motor look rather small.
What are their weights?

What kind of encoder does that motor use? being a servo motor, it would be "built in"?

so 157.5Nm x 4500 rpm = 74.22kw peak.
should be a nice sized power plateu, unless your batts can put out ~80kw at a high enough voltage

Matt

Post by **coulomb** » Sun, 20 Sep 2009, 17:28

e-ghia wrote: Here's the 55kW drive that we'll use for this.

Is that 55 kW with a 50% (or so) overload capability? Controllers often come with two power ratings (e.g. our 75/90 kW). The first can be overloaded by 50% for short periods (minutes) of time; the latter can be overloaded by 10% (or so) for like an hour. So the former is more useful for EVs. Then you know the real controller limits.

Any tips?

Open the outer covers over the connectors. Can you see DC+ and DC- ? If so, good; that's where you will connect your battery (via a precharge circuit). There will be L1/L2/L3 connectors in there. Are there some bulky inductors nearby? These can probably be taken out to save space and especially weight.

Before you do this however, are the input rectifiers diodes or SCRs? If diodes, you can do a bad boy voltage doubler from single phase mains (don't forget an inrush limiter, like a high power lamp, in series with active). That allows you to at least power up the motor and controller, before you have the batteries all set up with balancers and racks and cables. You should be able to do a motor tune function (read the manual carefully for how to do this; it varies with each controller). That will power up the motor and you may be able to read out some parameters like resistance and reactance.

Some clues here.

Post by **HeadsUp** » Fri, 23 Oct 2009, 20:27

wouldnt mind a photo of the inside of that controller to confirm physical placement and access to DC bus

anywun ?

Post by **Johny** » Fri, 23 Oct 2009, 21:11

The hardware manual for the ACS800-U1 states:
"Brake chopper - ABB has brake choppers that, when applied with appropriately sized brake resistors,
will allow the drive to dissipate regenerative energy (normally associated with quickly decelerating a
motor). Proper application of the brake chopper is defined in chapter Resistor braking. This can be
applied to a single drive or multiple drives with DC bus connected to allow a sharing of regenerative
energy."

Post by **Johny** » Fri, 23 Oct 2009, 21:24

...and from the same manual.

This is for the R6 enclosure but all frame sizes use the same terminal layout.
The three un-populated terminals are R-, R+/UDC+, UDC-
where
R = Brake Resistor
UDC = DC Bus

Post by **Johny** » Fri, 23 Oct 2009, 21:40

I should just post the URL to the manual shouldn't I?
stevenengineering.com/Tech_Support/PDFs/35ACS800-01HM.pdf

Post by **e-ghia** » Fri, 30 Oct 2009, 20:46

Sorry for the late reply, but we've been rather busy with our mechanical installation.

Ok, here's an actual photo of the business end of the drive. There are 3 terminals: R-, UDC+/R+ and UDC-. But that's not to say that we know what to do with them...

We have decided to run 12 48V modules = 576V. I notice that acmotor installed these as two strings: +288 and -288. Why is this? Really what I'm trying to say is, where do we go from here?

The motor is installed - mechanically that is - and the batteries have been imported and picked up. Sorry for the bad photo of the motor install. It was taken with a phone, and I'll upload a better picture soon. In person, it looks great, and we have the motor-install grin.

Here's a shot showing the front and rear battery packs and the VFD tucked behind the firewall.

So, now what?

Also, we are using contactors to separate/connect the 48V modules. We could use some help selecting the proper contactor. I thought we could use the Curtis SW82 - a DPST - using 1/2 as many considering the smaller footprint and lower overall cost - found here.

Am I on the right track? Are these not enough or overkill?
Also, should we consider some sort of spike suppression for these when the string(s) is connected?

Forgive the ignorance, but again we are mechanical engineering students. Anyone need help with an adaptor plate or taper-lock?

(Maybe I should start a new thread on HV electrical design...)

Post by **woody** » Fri, 30 Oct 2009, 21:36

e-ghia wrote: Sorry for the late reply, but we've been rather busy with our mechanical installation.

Ok, here's an actual photo of the business end of the drive. There are 3 terminals: R-, UDC+/R+ and UDC-. But that's not to say that we know what to do with them...

UDC+ goes to +288V
UDC- goes to -288V

R+ goes to your braking resistor / frypan
R- goes to the other end of your frypan.

e-ghia wrote: We have decided to run 12 48V modules = 576V. I notice that acmotor installed these as two strings: +288 and -288. Why is this? Really what I'm trying to say is, where do we go from here?

The idea is that the centre of the pack (0V) is grounded to the body through a high resistance monitored connection. That way when an HV shorts to the body it is detected and the contactors will open.

The other idea is a floating pack, but that way you don't know when the first short happens, and the second short is catastrophic.

e-ghia wrote: The motor is installed - mechanically that is - and the batteries have been imported and picked up. Sorry for the bad photo of the motor install. It was taken with a phone, and I'll upload a better picture soon. In person, it looks great, and we have the motor-install grin.

The whole car looks great - good ECO colour

e-ghia wrote: Also, we are using contactors to separate/connect the 48V modules. We could use some help selecting the proper contactor. I thought we could use the Curtis SW82 - a DPST - using 1/2 as many considering the smaller footprint and lower overall cost - found here.

For continuous amps, 18kW / 600W =~ 30 amps, and you're only going to do that for 40 minutes until; the pack is flat, so I think Albright SW60s will be big enough, but they aren't available in double-ended, so SW80s not overkill.

You should also have 1 big-ass contactor (EV200?) for a panic switch.

While you are working on the battery pack, you can start playing with the controller and motor - jack up the back wheels, get an electrician to hook you up with 3 phase power safely, hook up the throttle (analogue input), encoder, etc, and see the wheels move.

Please note it will not be good to hook the batteries up while the controller is plugged in or has been recently, the controller has a large bank of DC capacitors which will be at a different (but similar) voltage to your batteries and there will most likely be a large current when you connect.

The DC capacitors smooth the rectified AC from the 3 phase input, so they will be at different voltages depending on the 3 phase voltage which varies a lot (20%+).

a4x4kiwi's blog has a few things which may augment your todo list and/or answer some questions.

Post by **HeadsUp** » Fri, 30 Oct 2009, 22:20

scuse my ingorants

but i thought the two separate battery packs are required because the original AC 3 phase input into the controller was also split into two half sine waves when it goes into the inverter part ( DC bus ) of the controller ?

pardon my kindergarten electronics

I know the Azure DMOC controllers can be fed with a single bank of DC supply at 100 - 400 VDC

but this wouldnt work with a Danfoss or ABB VFD would it ?

Post by **Electrocycle** » Fri, 30 Oct 2009, 22:30

yeah it's just a +- DC bus, two connections.

The 3 phase AC is fully rectified to DC

Post by **Johny** » Fri, 30 Oct 2009, 23:05

While the SW60 or SW80 will be rated well for current it is not rated to switch 600 VDC. You really do need at least one contactor rated at 600 VDC. The EV200 is a good contender. One of the EV suppliers in the US has them for US$89 - I forgotten who - anyone remember (it's on my PC at work).

If you are confused about +/-288 VDC then just series the whole lot up to make your 576V setup. + to UDC+ and - to UDC-. woody is then talking about grounding the centre of the whole lot. acmotor has it via a fuse, woody is suggesting a resistor and monitoring system. Either way or not grounded at all will work - it's a safety issue. Any spare contactors you have can be inserted along the line every here and there to reduce voltage when the system is off. Again acmotor has them every 48 Volts.

If you guys are not familiar with high voltage and high current please, please get some advice and/or permanent help. Maybe you can excite some of the Electrical engineering students to get involved.