Smart Roadster (with Prius Gen3 Inverter and Outlander Rear Motor)

Tell us about the project you do with the open inverter
arber333
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Re: Smart Roadster

Post by arber333 »

Hm...
I would then advise you to rather make plans for higher voltage and use inverter to buck down dc voltage for dcdc and other auxilliaries than adding another pack with different S rating.
Yes you might loose charger that way, since you need to boost voltage from ac rectified. But...
From 230Vac you get 310Vdc rectified which shouldnt cause aux devices any problems. Maybe you could still use charging, but you would have to use additional rectifier bridge and a contactor with precharge resistor. I wonder what would happen if you would use evse PP pin to signal boost to 500Vdc...
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Re: Smart Roadster

Post by Pete9008 »

Stripped the I-Pace valve block down and ended up with these air con bits to use:
BallValves.JPG
A couple of motorised ball valves. The left hand one is simple ball valve and may not get used. I'm hoping the right hand one is an expansion valve and if so it will get used to try and switch the Smart's condenser to work as an evaporator.
TXV.JPG
A standard thermal expansion valve with a solenoid valve to enable/disable flow and a heat exchanger. These will be split and the valve will be used to replace the existing one on the Smart's evaporator to give on/off control (if it can be made to fit, if not the simple ball valve above will be used), The heat exchanger will be used as a condenser for heating the cabin and battery (if it can take high side pressure - any thoughts on this?)
EXV.JPG
An electronic expansion valve with a heat exchanger. This will be used for battery pack cooling (hopefully not be needed but allowing for it in the design just in case).

There are various other bits - refrigerant pipes and connectors, water hoses and what I think is either a temperature sensor or pressure sensor for the low side refrigerant. Even if I only use half the bits it will have been worth buying the valve block.
WaterHeater.JPG
VAG water heater as a backup for heating when it is too cold for the air con to work in heat pump mode.

Other big news - I picked this up today! :
Battery.JPG
12kWh, 6 module (96cell) pack from a 2020 BMW 330E, complete with the HV connecting cable and LV connector cable tail. Yet to check the state of the cells as I'm having trouble getting any response on the CAN bus connector but fingers crossed they are in a good state!

I'm still watching out for a few other bits but hopefully that's most of the main components for the conversion sourced :)
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Re: Smart Roadster

Post by Pete9008 »

Quick update on the CAN logging side. The original plan was to use GVRET logging to an old CF18 toughbook running SavvyCAN but that's not going to work. It's an old 32bit machine which SavvyCAN doesn't support, tried installing Qt to build SavvyCAN from source but the version of Qt needed for SavvyCAN isn't available for 32bit, tried compiling Qt from source but it doesn't seem happy with something in the OS so I've given up!

Instead I've added an SDcard to my GVRET box:
GVRET_SDcard.JPG
It's a standard SPI SDcard breakout board and wires straight to the SPI header on the Arduino Due (SS is taken fron pin10 on the Due). What's really nice is that GVRET supports it as standard and once a card is inserted it finds it and happily copies all the CAN data to the card as well as to SavvyCAN. No need for a laptop to log data any more. :D

GVRET can be set to either change the filename each time it runs or append the data to the existing file. Neither of these options really works for me (I'm not organised enough to record which file is what) so I have also added a real time clock module. It now timestamps the new file with the correct data which makes it much easier to tie a log file up with a particular test run.
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Re: Smart Roadster

Post by Pete9008 »

Ohh - and the battery checks out OK (around 5mV variation from module to module, 2mV within each module, with an average of around 3.8V). :D

Couldn't get hold of a Teensy anywhere, and didn't want to buy a SimpBMS as I don't know whether I'll be able to use it (depends on how many battery modules I end up using) so ended up porting some of the SimpBMS code to the Due and running it on the GVRET box.

All credit to Tom, after a few changes to suit the new CAN library, his code ran fine and pulled the data out of the battery a treat.
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Re: Smart Roadster

Post by marcexec »

I found another conversion - how's your German?
https://www.goingelectric.de/forum/view ... hp?t=49327
Haven't finished reading it yet, but apparently +50kg is fine with the German Tüv, provided there's a spacer on the springs
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Re: Smart Roadster

Post by Pete9008 »

marcexec wrote: Mon Jun 27, 2022 8:03 am I found another conversion - how's your German?
Terrible! In fact it's embarrassing just how bad given how good everyone's English on here is :oops:
marcexec wrote: Mon Jun 27, 2022 8:03 am https://www.goingelectric.de/forum/view ... hp?t=49327
Haven't finished reading it yet, but apparently +50kg is fine with the German Tüv, provided there's a spacer on the springs
Put it though google translate - many thanks for the link, it's a very interesting read. Not sure about the 50kg though, if it went through SVA then it may be possible to recertify it but I'm keen to avoid that.

The weight data on page 5 is very useful. Unfortunately it backs up the estimates I've already made - I'd been hoping they were pessimistic! If I put 12kWh of battery in I'll end up with 20kg of payload left. What is interesting is how much can be saved by swapping to lighter seats - 21kg, that's almost another 4kWh!

My plan is still to run the car though July. In August I'll pull the engine, box, tank and other bits an pieces out and weigh/measure everything and then work out what's possible. In the mean time I'm just trying to get all the components and information for the conversion together.

I'm also getting quite attached to the car, it's not fast but it's quick enough, and it does handle very nicely (despite what I think are tired dampers, loose lower ball joints and a total lack of caster on one front wheel!). The engineering on it is nice too, the Smart's designers really did start from a clean sheet, they maybe got a few things wrong but overall it works well. Moving to an electric drivetrain will improve it though, the current engine and box don't do it any favours at all.
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Re: Smart Roadster

Post by Pete9008 »

Progress has been a bit slow on this lately but probably enough to be worth an update!

The insurance has now lapsed on the car and it has been sorned from the start of this month. Fortunately before this happened I was able to collect a couple of hours CAN logs.

This was the CAN logging setup I ended up with:
SavvyCAN_Engine.JPG
The GVRET box is connected inline with the engine ECU, the car side bus connects to one CAN port on the box with the engine on the other. The box is then set to do port forwarding so that the intercepted messages get forwarded on to their destination as well as being logged. This setup means that the log file contains details of whether the source of the message was the car's bus or the engine ECU and so saves a lot of guessing. Tip - if doing this and saving to SD card make sire that you set the box to GVRET format, if you leave it in the default CRTD mode it doesn't save the source bus information.

The power supply for the box was initially from a cigarette lighter USB adaptor which meant that it turned on and off with the ignition (and so could be left connected without draining the car battery). Unfortunately, while the car started and appeared happy, the ESP and ABS were non functional. Presumably there is some early initialisation that was missed while the box booted up. Powering the box from from a separate battery sorted this.

Some initial captures were taken with the car up in the air and the wheels spinning to identify the main bus messages and then more logs on the road to get a better understanding.

I found it quite surprising just how useful the full CAN bus data can be. I've used OBD in the past for diagnosing problems and while it's useful you only get half the picture. The following isn't particularly EV related but I found it interesting so will include it here.

Take for example the ABS - the car is happy, no fault codes, no warning lights and no odd behaviour, however, looking at the CAN logs for the ABS sensors (message 0x080, two consecutive bytes per wheel):
ABS.jpg
Two of the traces, the front wheels are fine, nice and clean. The two rear wheels aren't quite so good, one is OK just a bit noisy but the other is obviously on its last legs. Lots of noise and the occasional full scale spike - not nice! Quite surprised the ABS warning light isn't on yet.

Looks like a pair of new rear ABS rings will be needed while the car is in bits.

Also think I have identified the messages needed to keep the ESP working. I'm sure a lot of people will think that this isn't worth the bother and if it was just a summer car I would agree but the plan is to use it all year round and having had a couple of interesting handling experiences with rwd cars on greasy roads in the past I'd prefer it to continue to function. Initial tests on the car lift (front wheels stationary so ESP trying as hard as it could to keep the rear wheels stationary identified the relevant message from the ESP unit (message 0x208, byte2, 8bits). This seems to be a torque limit massage which normally sits at a value of 255. When the ESP becomes active it drops to a lower level which appears to be the torque which the engine should limit to. This only makes sense if the engine also tells the ESP unit what torque it is currently generating and this appears to be message 0x310, byte 4, 8bits.

Below is a plot taken while out on wet roads going round a fairly long. open, medium speed corner. Now going round the corner I didn't notice anything going on, the throttle possibly felt a little unresponsive but nothing concerning. On leaving the corner I noticed the ESP light flashing and at the time thought it must be the earlier mentioned ABS issue starting to act up. On analysing the data though the ESP can clearly seen to be working!
ESP.jpg
The red trace here is the torque output torque message sent by the engine, the blue trace is the torque limit sent by the ESP module and the green trace is the reported boost. I haven't shown the throttle but it essentially matches the engine torque output trace (but scaled). It can clearly be seen that when the ESP becomes active (when the blue ESP trace drops down from its normal unlimited 255 value) it effectively takes over control of the engine replacing the red trace.

What confused me initially was that the engine output (red trace) didn't seem to follow the commanded ESP torque value. To better understand what was going on I added the boost trace. This clearly shows that the engine output torque message is lying and the torque does actually follow that commanded by the ESP message. On thinking about this a little more it appears that the engine message isn't actually the torque output from the engine but rather the torque requested by the driver from the throttle. This makes perfect sense because the ESP module can then use this to determine when it is safe to pass control back to the driver (obviously a bad idea if the car is still slipping slightly and they have the throttle wide open - which is actually quite likely as I'm pretty sure my automatic response to the slightly unresponsive throttle was to unconsciously press it down harder! - can be seen by the rise in the red trace just after the ESP kicks in).

On the traces you can clearly see the wiggle on the blue trace where control is 'taken' by the ESP module (~210000) and then returned to the driver (~214750). I'm wondering whether the is also a slight reduction in the throttle even after control is returned until the ESP value returns to the full 255 value as there seems to a step in the red torque curve there but there isn't enough data to be sure.

So the plan for the conversion is to send a scaled value of the throttle pedal position on the 0x310 message and accept a torque limit message to inverter on 0x210. Hopefully that will allow the ESP operation to continue to function and if not hopefully there is enough captured data to figure out what else is needed.

On a completely non related topic I have also started playing with a replacement for the rev counter. This is the standard instrument cluster:
DashGuages.JPG
The right hand RPM gauge will be fairly useless following the conversion. I considered repurposing it for something but it seemed a bit of a waste of space. Instead I'm going to use a Pimoroni Hyperpixel display, these are round, 480x480 pixel, IPS displays that are just about the right size to replace the rev counter. A Pi Zero 2W plugs onto the back meaning that it can be programmed using any standard Linux tools (I've got it set up with remote cross compile and debug in Qt which simplifies development). This is a mock up of what the screen will look like in normal operation:
RangeDisplay.JPG
The ring round the top half will show battery current (regen on the left, drive on the right, colour coded to battery capability - green up to 3C then turning to red), the middle bit is predicted range with inverter and motor temperatures below and then battery voltage and temperature graphed below that (again colour coded, red for anything that is not considered normal - no idea what sensible limits should be here!). Beneath that is a general info/warning/error display. It will also be active during charging to show charge status.

There is also a I2C to CAN bus board connected that will be used to pick the required messages up of the bus.

At the moment it's just a basic framework and still needs all the CAN message handling adding.

I also added Navit sat nav to it - not quite sure why but then why not!
SatNav.JPG
The satnav turned into a bigger project that the gauges in the end, and probably not worth the bother, but it's done now.

Unfortunately I'm way behind on the house and still have a bathroom to refit and couple of rooms to decorate before I can start pulling the car to pieces but will try to keep chipping away at it in the background.
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Re: Smart Roadster

Post by Pete9008 »

I'm looking at options on chargers and would appreciate opinions. I now have a Chevy Volt Gen2 charger chosen because it is relatively light and compact (and the Roadster has neither spare load capacity or space!) but am wondering whether it needs to be on the car at all.

The two options under consideration:

Option 1 - Mount the charger on the car with a Type2 charge socket.
Pros - simple/easy.
Cons - have to carry the added wight of the charger and can only slow charge (3.3kW).

Option 2 - Mount the charger on the garage wall connecting to a Chademo charge socket on the car.
Pros - Lose the weight and space occupied by the charger on the car, adds fast charge capability while out.
Cons - More complicated (need to add Chademo support for the car and essentially build an Chademo EVSE out of the Volt charger (although can probably cheat on simplified protocols a bit for the EVSE).

For information >95% of my charging will be done at home. The option to fast charge while out does increase the flexibility of the car (longer trips become possible) so it is attractive.

So, the questions:
Is option 2 a stupid idea/what am I missing?
Has anyone done anything similar?
Is it even possible to buy Chademo plugs?
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Re: Smart Roadster

Post by marcexec »

Thanks for the CAN "blogging" on ABS and ESP there, that's brilliant!
Love the round display, maybe I'll put it on the bike to replace the temp gauge...

The Chademo option sounds neat, you could 3D print the connector: https://www.thingiverse.com/thing:121581.
I think Ben Nelson did it for his i-Miev & home solar.
I'd go with CCS (i3 LIM) to future-proof it, though.
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Re: Smart Roadster

Post by Pete9008 »

Thanks for the link, 3D printing does look like the only option at the moment. Unfortunately it would need to live outside and be used untended so I wouldn't be comfortable going down that route. Thinking it will have to be an on board charger, at least initially - I need to concentrate on the stuff needed to get the car usable rather than doing my normal scope creep trick and turning it all into a much bigger project.

CCS would be very sensible in terms of future proofing but the added complexity of the comms protocol puts me off (again scope creep), also not sure that the socket would fit in the old fuel filler hole!

I'm very happy with the display. It's only 400nit brightness (some IPS ones are 1000) which would make it marginal for outdoor unless it's shrouded but it's pin sharp and very easy to read. It does have a capacitive touchscreen too.

The only small issue is that it randomly sometimes boots up with a 6pixel vertical offset. Not a big issue but irritating. After a bit of digging think I found the problem this morning, the hyperpixel2r-init script that configures it on boot appears to hold the SPI CS line low during the LCD controller reset - and it doesn't like this. Taking the line high following the reset command and then waiting for the reset to complete before taking it low again seems to have fixed it (fingers crossed though, being random and intermittent makes it difficult to be sure). Have suggested the mod to the manufacturer so hopefully the install scripts will get updated.

For anyone else wanting to cross compile on the Pi this (http://heavybaremetal.com/index.php/blo ... berry-pi-3) is the best guide I found for setting it all up (tried a couple of others before this that didn't work). The critical thing seems to be finding compatible versions of the Pi OS. libraries and Qt and this guide specifies them all. Unfortunately it needs the use the older Buster OS rather than the current 64bit Bullseye but for what I'm doing it doesn't make that much difference.

Will share the Qt code for the display once it is receiving CAN messages and can do something useful.
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Re: Smart Roadster

Post by Pete9008 »

It's been almost 2months so it's probably time for an update!

Unfortunately there is not a lot to report, I normally suffer quite badly with hayfever/allergies in the summer but this year it has completely wiped me out so there has been no progress on the car. What I have been doing though is a lot of thinking about the build and fair bit of software.

Now I'm not good at doing things more than once, I get bored second time round, so tend to try and identify any risks and work on them separately to try and make sure that they don't derail the whole project. On this the risk was starting to look like using using motors above base frequency with OpenInverter. There were a number of threads about unwanted regen, unwanted acceleration, poor acceleration, etc. One option was to move to an Outlander inverter but this meant more weight and didn't fit well with the planned install. Not having access to a working motor/inverter I decided to try and simulate the system (see viewtopic.php?t=2611 for details). Now the jury is still out but I'm pretty confident that OpenInverter can do a good job of driving an IPM above base frequency so the plan is to stick with a Toyota Inverter running OpenInverter firmware.

Which inverter is a little up in the air. I'm considering a move to a RAV4 inverter as it appears to offer a bit more power as standard. If a cheap inverter pops up I'll probably get one to have a look at and see what's involved, otherwise I'll stick with the Prius Gen3 but with MG1 and MG2 paralleled.

Other changes are on the logic board I started (see viewtopic.php?p=39624#p39624). Now this got to around 90% complete before it got sidelined but it's going to get changed. Couple of reasons. Firstly with MG1 and MG2 paralleled there is not much need for the STM32L4 processor that drove MG1. Secondly the only other reason for the this processor was to offload high speed data logging to an SD card. A suggestion on another thread has led to a rethink on this. Changing the ESP8266 on the board to an ESP32 and moving the SD card from the STM32L4 to the ESP32 provides better overall functionality (integrates the data logging with the wifi to allow remote access), gives a simpler board and reduces the pin count on the connector (which was a bit tight). The plan is to pull the STM32L4 processor out and into a separate module or move to another VCU.

Still got the house DIY to do so will be another month or two before any real work starts on the car :(
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Re: Smart Roadster

Post by Peter »

Hi Pete9008. Not sure if I am missing something here but what motor are you contemplating ? I run a Tesla SDU fitted to a bespoke subframe in my 450, all depends how courageous you are :-)
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Re: Smart Roadster

Post by Pete9008 »

Still the Outlander rear but hopefully at a bit more than stock power, maybe up to 100kW peak (got a track day car for when I'm feeling courageous, this is just for day to day use).

I think the Prius Gen3 will be up to it but I'd like to be sure.

Edit - not sure my batteries would be up to driving a SDU either!

What did you do on the brake servo on yours, vacuum or ibooster?

Edit2 - been wondering whether to modify the rear subframe or not, modifying it might make fitting everything in much easier. Did the DVLA have any issues with it being modified?
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Re: Smart Roadster

Post by Peter »

Hi Pete9008. 100kW would be fun, I run up to 75kW which demands serious concentration :-) I have 18kWh of Volvo V60 batteries (330v), range 65miles or 40miles if I am feeling very naughty.
Brake servo uses a 12v vac pump and a reservoir, a bit noisy, pump kicks in every second pedal press and have fitted disc brakes to the rear. In retrospect the drum brakes would have been ok as regen slows the car enough. Contemplated an ibooster but space is limited.
Took the car for an MOT, no issues there. Adrian Flux told of the mods, again no problem.
As far as the DVLA are concerned does modifying or reworking a 'subframe' alter the chassis or not ??
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Re: Smart Roadster

Post by Pete9008 »

Interesting, I'd assumed you were running more than that! Looks like I can dial things back a bit :) Ill have less batteries (12kW to start with) but don't mind abusing them a bit to see what's possible.

Thanks for the brake info, with that in mind I'll stick with the drum brakes. As you say, with the regen, they shouldn't have to do too much and I don't want to risk the rears locking up first (had that on a car before and its not nice!).

No idea what the subframe counts as, it depends how you read the very vague guidance, hence the question. I'd like to modify it but the DVLA seem to be getting keener on inspections so wondering whether to try and keep it standard, or at least looking standard to anyone not familiar with the car!
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Re: Smart Roadster

Post by Peter »

With respect to locking rears I can set the regen parameter so that just touching the brake pedal means instant lock up !!
Next job is to fit a brake pressure transducer so that governs how much regen to allow based on pedal pressure and motor speed.
Will be interesting to see what your 0-60 time will be if you are pulling 100kW, I can dial up my parameters to achieve 4 secs and possibly just under that but I get too much wheelspin and car does a slight wheelie, need to video that :-)
As to the regs, seems most are sticking to what can be classed as no chassis mods, MOT man was in awe of the work and had no problem passing inspection so why rattle the DVLA. They class my car as a Hybrid, system wont accept only ELECTRIC when the MOT man tries to update with each MOT and log book still has the emissions value but I pay no VED, its a 2011 model so I would only be paying £30 per annum if it were ICE.
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Re: Smart Roadster

Post by Pete9008 »

That is part of the attraction of the iBooster, you can read the pedal position over can to control regen, just not sure it will fit.

Starting to wonder if I'm over estimating the power I need. Only ever driven ICE for any length of time and know that 150bhp in a Smart would be enough to be fun. 150bhp is around 100kW but is that really the case? I know the power delivery of an electric motor is very different but I'm amazed that you get 4sec 0-60 from 75kW!

Not too worried about the MOT, but a little worried about inspections getting more rigorous before I get the car finished (had the issue in the past when building a kit car just before the SVA came in) and would hate to have it flagged as needing an IVA.

Edit - In terms of performance what I'd like to achieve with this car is a 0-60mph in the region of 6-7sec but with good acceleration up to 70mph too. Not bothered about speeds higher than that. ICE experience says that this would need around 150bhp/ton. How does this translate to an EV, is a straight bhp to kW conversion representative?
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Re: Smart Roadster

Post by Peter »

I looked at the ibooster but it wont fit in the space under the car.
EV being instant torque so acceleration is good from standstill so that decreases 0-60 time against ICE.
6-7 secs should be no problem, good acceleration to 70mph, once you have the motor in the car and are able to tweak the parameters its good fun.
I would estimate 12kWh will get you 35-40 miles with gentle(ish) driving.
My battery box is under the car, have you looked at that location?
I am looking at another possible conversion now, so I am thinking of either stripping my Smart as donor for another vehicle (more of a daily runabout) or possibly selling as a runner but only to forum members who have the knowledge and would be safer understanding what they are dealing with. Its all down to funds which way I go.
Where are you based?
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Re: Smart Roadster

Post by Pete9008 »

Think you must be pulling more power than that at the end of a run. Have done a few sums and to get a 4sec 0-60 in a 1ton car you need about 178kW (230bhp) - just wondering if there is a 1 missing in front of the 75kW you mentioned? The SDU would be capable of that kind of power.

6sec would need around 120kW (150bhp) and 7sec around 100kW (130bhp)

The above assume constant torque and don't allow for motor, inverter or drivetrain losses so it would need a bit more in reality. Looks like my goal of 100kW is in the right ballpark though.

There's not much space under the Roadster so the aim is to get it all in the engine bay!
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Re: Smart Roadster

Post by mjc506 »

Why assume constant torque? :)

75kW and 1000kg gives me 4.65sec to 60mph (ignoring physical limits like traction at low speeds and drag)
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Re: Smart Roadster

Post by Pete9008 »

mjc506 wrote: Fri Sep 30, 2022 9:44 am Why assume constant torque? :)
Because it's the worst case, in reality torque drops as speed increases (well it does for permanent magnet motors above base freq, don't know about the SDU).
mjc506 wrote: Fri Sep 30, 2022 9:44 am 75kW and 1000kg gives me 4.65sec to 60mph (ignoring physical limits like traction at low speeds and drag)
I would really like this to be the case, I just can't get my maths to work :( My, admittedly simple, sums are:

v=u+at or v = at (if starting from zero). So to get to 60mph, or 26.7m/s in 4.65sec gives a=5.74m/s2 (or around 0.58G which seems reasonable)
force = ma or 1000 x 5.74 = 5740N
power = (force * velocity). At terminal speed (which is where power is highest) this is 5740 x 26.7 = 153kW

Where have I gone wrong? Or are you referring to average power over the duration of the run (which would be 75kW) rather than the peak power needed at the end?

Edit - thought about it a little more and see what you mean, if you could use 75kW throughout the run then it would do it. The trouble is both Peter's SDU and my Outlander motor are single ratio transmissions so torque is limited by how many amps you can get though the windings which remains relatively constant as the car accelerates (also limited by grip but thta's a different matter) an the power increases with speed. In the case of a PM motor the torque will start to drop once you get above base freq, not sure about the induction SDU. So I think may way of calculating it is reasonably representative but I could well be wrong :)
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Re: Smart Roadster

Post by Pete9008 »

mjc506 wrote: Fri Sep 30, 2022 9:44 am Why assume constant torque? :)

75kW and 1000kg gives me 4.65sec to 60mph (ignoring physical limits like traction at low speeds and drag)
Just twigged - you weren't serious were you! :lol:
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mjc506
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Re: Smart Roadster

Post by mjc506 »

Yeah, it depends where the bottleneck is. Usually the batteries (especially short term, inverters and motors tend to be thermally limited so can go a bit higher for a few seconds). So that's a DC power limit, so AC amps (and hence torque) can be quite high at low rpm. At one extreme (locked rotor, 100% duty cycle PWM) you're essentially shorting the battery through the motor coils, so in the order of 1x10^3 amps. (Plus the inverter will be acting like a buck converter, so amps could be higher) A lot of that will be lost to heat/saturation/etc, but there's still a fair amount of torque there.

So from 0rpm, you have a 'fairly constant' torque region, limited by motor saturation and max IGBT currents (this might be two separate limits), then once you clear that, the rest of the run is constant power, limited by the batteries (or maybe inverter/motor thermals, but unlikely to be a big issue for 0-60 runs!)

For a power limit set to 75kW, accel limit set to 1G, 1000kg vehicle, I get about 5.2sec to 60mph (frictionless vacuum etc :) )
Pete9008
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Re: Smart Roadster

Post by Pete9008 »

Interesting, I'll have 32Ah cells so was working on 10C or 320A for 10sec max and the inverter limiting the motor currents at a similar level. Would you push it a bit harder at low speeds?

If so I may have to think a bit more about whether to stick with the Prius inverter.

Edit - thinking about it probably not, more than around 0.5G on road tyres is just spinning the wheels.
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Peter
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Re: Smart Roadster

Post by Peter »

With the Openinverter control system on the SDU you can adjust Boost, Fweak and slipstart, all these parameters (and more) allow the power to be adjusted so you can govern the performance. If you just want to be mega quick up to say 60mph and then power tails off it can be done. Not sure how the Outlander motor performs and if the Openinverter control for that inverter uses the same parameters. Even so with 100kW you will be flying :-)
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