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all I want to do is limit the max DC current draw from my pack to 600A. I did try reducing the Drive % limits to about 450A RMS, but the car was undriveable, I could barely get to 20mph. Any help in interpreting these various current units gratefully received ...

View attachment 123850
Mmm braver man than I to play with the Motor and control settings, although I agree this page looks like a way to set max current to 600A. I would do a drive with recording running, say battery (DC) amps, vs % torque motor speed etc and then import, via .csv into excel and see if/ where you see approaching 600A or more. A meter would do the same, but I find they move too quickly and are too distracting when driving.

I haven't run a plot for ages but here is an early one when testing.. Tau software is really good for this kind of thing
Rectangle Font Parallel Slope Pattern
 

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Has anyone tried to get support from Dana TM4 for these components, since the motor and "TM4 Tautronic" controller are now Dana TM4 products, after Dana TM4 acquired SME? It's probably futile, but if anyone could reach the right person it might be more productive than support routed through the NetGain people who have nothing to do with the design or production of the motor, controller/inverter, or software.
 

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Mmm braver man than I to play with the Motor and control settings, although I agree this page looks like a way to set max current to 600A. I would do a drive with recording running, say battery (DC) amps, vs % torque motor speed etc and then import, via .csv into excel and see if/ where you see approaching 600A or more. A meter would do the same, but I find they move too quickly and are too distracting when driving.

I haven't run a plot for ages but here is an early one when testing.. Tau software is really good for this kind of thing
Yes, probably a good next step to try it live and log it, and see if that makes any sense. I have a live ammeter running and I never get close to 600A, but that's not the point, I want to ensure all the safety systems are in place. My main concern was not actually breaching 600A on current draw, but exceeding the charge limit for the Tesla modules on regen if coming off throttle from high speed (like on the motorway) which the software supposedly allows you to do.
 

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Has anyone tried to get support from Dana TM4 for these components, since the motor and "TM4 Tautronic" controller are now Dana TM4 products, after Dana TM4 acquired SME? It's probably futile, but if anyone could reach the right person it might be more productive than support routed through the NetGain people who have nothing to do with the design or production of the motor, controller/inverter, or software.
I might try this, because Netgain are just ignoring me.
 

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I might try this, because Netgain are just ignoring me.
Netgain just dont answer emails but they DO accept phone calls. Hunter really knows his stuff.

YES Brian It would be great to source info (if not hardware / software) from Dana, but I've only got the hand .. .. if anyone has a contact there it would be wonderful.
As with Yasa and some of the amazing e-motors used for aero eg 500kW (540hp) from tiny <50kg axial motors, (but with eyewatering costs) I get ‘Sorry Sir only for OEM car companies’
 

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Does anyone know how to set a maximum current that the ACX1 controller can draw from the pack? My pack is fused at 600A, and I want to make sure that cannot be exceeded.

There is a 'motor limit current map' in the SME software, might this be it?
A current limit in a controller would normally be motor current, not DC link current, and I agree with this conclusion:
The Tau software has a Motor Current Limit Map, example attached. It shows that 100% of the maximum current can be drawn for any motor speed (the red line), whereas the green line shows the percentage of maximum current that the controller can supply to the pack under regen.

The units imply that 750 A RMS is the maximum current that can be drawn (I’m using the low voltage Hyper 9 system).

I am assuming that because it refers to A RMS, it’s likely to be referring to AC motor current, not DC pack current.
There is no need for a motor controller to even be aware of the DC link current, except to protect itself; in a rational integrated system, the BMS would tell the motor controller when power demand needs to be reduced to protect the battery, regardless of the current from the battery (depending instead on a more sophisticated combination of temperature, and trends over time of current).

Netgain’s webpage refers to “750A Peak”, which is not the same as 750 A RMS in the Tau software, and also not the same as the 850 Amps that the performance charts (such as the one from Negain) above shows.
The way it is given on the NetGain motor page for the HyPer 9 IS, the 750 A looks like a battery current peak, because it is given with battery voltages. That is not the same as motor current, and it is not apparent where NetGain got this value.

The HyPer 9 and HyPer 9HV specs show about the same maximum power from the battery - with about 1.5 as much voltage as the regular model, the HV uses about 2/3 of the maximum current, which makes sense.

If you look at the peak performance data published by NetGain for various voltages, calculate the DC link for corresponding to peak power based on mechanical output power and efficiency, and divide by the (approximate) DC link voltage you get the peak DC link current in that test.

For example:
at 72 V DC link, peak power is 60.3 kW and efficiency is 91.7% so electrical input power must have been 60.3*1000 W / .917 = 65,758 W, and so current was 65,758 W / 72 V = 913 A.

Here are all of these values for the published peak performance charts for the regular HyPer 9 and HyPer 9HV systems:
SystemDC Link test voltage
V
peak mechanical power
kW
efficiency at peak power
%
calculated input power
kW
calculated DC link current
A
HyPer 97260.391.7%65.8913
HyPer 98471.493.0%76.8914
HyPer 99681.393.9%86.6902
HyPer 910893.993.5%100.4930
HyPer 9120102.894.3%109.0908
HyPer 9132112.893.7%120.4912
HyPer 9HV12073.093.8%77.8649
HyPer 9HV13280.393.2%86.2653
HyPer 9HV14488.093.8%93.8652
HyPer 9HV15695.594.4%101.2648
The current can be much more than 750 A for the regular (not HV) version, even at the highest voltages. It isn't a constant value, but it's close enough (given that the DC link voltage is only an approximation) for a given system (regular or HV), that I suspect that the controller has an internal input (DC link) current limit.

So I am confused … all I want to do is limit the max DC current draw from my pack to 600A. I did try reducing the Drive % limits to about 450A RMS, but the car was undriveable, I could barely get to 20mph. Any help in interpreting these various current units gratefully received ...
Various information tracked by the controller could be used in logic to set a limit, if the current is not directly available, but the obvious solution is to use the input power (or even just output power... whatever is available) and divide that by battery voltage (or even just a constant nominal voltage is actual battery voltage isn't available) to calculate what the battery current must be... and limit that if you can.

Alternatively, if there is a configurable power limit, just set that to the value corresponding to the maximum battery current that you can tolerate multiplied by the lowest battery voltage that you will be using... and be unnecessarily limited in power when battery voltage is higher.

The best solution is obviously to find the actual input current limit parameter in the software, but of course that's exactly what you're asking for. ;)
 

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YES Brian It would be great to source info (if not hardware / software) from Dana, but I've only got the hand .. .. if anyone has a contact there it would be wonderful.
As with Yasa and some of the amazing e-motors used for aero eg 500kW (540hp) from tiny <50kg axial motors, (but with eyewatering costs) I get ‘Sorry Sir only for OEM car companies’
Yes, this is - unfortunately for DIY enthusiasts - a normal situation. Even in the case of BorgWarner, which offers direct-to-consumer sales and support via their Cascadia Motion division, the Cascadia Motion people don't actually make the motors. A direct Dana TM4 contact is a long shot; better documentation would also be good, but even that is unlikely.
 

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Firstly, thanks @brian for such a comprehensive post, really helpful. Might not get us to the answer we need just yet but very useful nonetheless.

A current limit in a controller would normally be motor current, not DC link current,
OK.
There is no need for a motor controller to even be aware of the DC link current, except to protect itself; in a rational integrated system, the BMS would tell the motor controller when power demand needs to be reduced to protect the battery, regardless of the current from the battery (depending instead on a more sophisticated combination of temperature, and trends over time of current).
Agreed, and this is exactly the situation I am in - I have an Orion BMS providing quite a sophisticated current map which I can't get the ACX1 to use.

The way it is given on the NetGain motor page for the HyPer 9 IS, the 750 A looks like a battery current peak, because it is given with battery voltages. That is not the same as motor current, and it is not apparent where NetGain got this value.
The trouble is, the controller and software documentation refer to RMS current everywhere.
If you look at the peak performance data published by NetGain for various voltages, calculate the DC link for corresponding to peak power based on mechanical output power and efficiency, and divide by the (approximate) DC link voltage you get the peak DC link current in that test.

For example:
at 72 V DC link, peak power is 60.3 kW and efficiency is 91.7% so electrical input power must have been 60.3*1000 W / .917 = 65,758 W, and so current was 65,758 W / 72 V = 913 A.

The current can be much more than 750 A for the regular (not HV) version, even at the highest voltages. It isn't a constant value, but it's close enough (given that the DC link voltage is only an approximation) for a given system (regular or HV), that I suspect that the controller has an internal input (DC link) current limit.
This means that at peak power, I would blow my 600A pack fuse. I don't want to do that!

The best solution is obviously to find the actual input current limit parameter in the software, but of course that's exactly what you're asking for. ;)
Yes ...

I will see if I can get hold of Netgain on the phone and/or try to run some diagnostics on the car. The controller will output 'DC bus' current and 'Motor phase current' via CAN, alledgedly, so I'll see if I can monitor those.

Thanks again.
 

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Hi everyone,

Starting my first conversion with a Mini Cooper 2007 and Hyper9 X1.

I would like to use the 8 modules from a BMW i3 battery pack.

At first, I was thinking to split these 8 modules in 4 groups of 96v parallel strings (4P2S?) but it looks like it will add a bunch of management complexity. I was also planning to use SimpBMS at the beginning because it’s compatible with i3 battery modules but since I’m planning to regroup some modules in parallel, I doubt it will work…

Looks like most of you are using Tesla modules, just wondering is someone already looked at the i3 batt option.

Thanks!
 

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Hi everyone,

Starting my first conversion with a Mini Cooper 2007 and Hyper9 X1.

I would like to use the 8 modules from a BMW i3 battery pack.

At first, I was thinking to split these 8 modules in 4 groups of 96v parallel strings (4P2S?) but it looks like it will add a bunch of management complexity. I was also planning to use SimpBMS at the beginning because it’s compatible with i3 battery modules but since I’m planning to regroup some modules in parallel, I doubt it will work…

Looks like most of you are using Tesla modules, just wondering is someone already looked at the i3 batt option.

Thanks!
The SimpBMS is actually the ideal BMS for parallel configurations since it communicates with the balancing circuitry on each module. That's why so many people use them for solar setups where modules are put in parallel (most solar systems are only 24 or 48v). I just yesterday shipped out a SimpBMS to someone who's going to use it with 14 Tesla modules in a 48v system (modules arranged 2s7p). In my personal project I have parallel modules as well. As long as you're not using more than a full pack of i3 modules, the SimpBMS is your best bet.

Parallel modules is what first led me to the SimpBMS. The cost to go with an Orion BMS would have been $2400 since I would have needed 2x 30s BMSes (one for each parallel string, my modules are arranged 5s2p).

I sell them on eBay: SimpBMS Tesla BMS For Tesla Model S/X Battery Modules | eBay
 

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The SimpBMS is actually the ideal BMS for parallel configurations since it communicates with the balancing circuitry on each module. That's why so many people use them for solar setups where modules are put in parallel (most solar systems are only 24 or 48v). I just yesterday shipped out a SimpBMS to someone who's going to use it with 14 Tesla modules in a 48v system (modules arranged 2s7p). In my personal project I have parallel modules as well. As long as you're not using more than a full pack of i3 modules, the SimpBMS is your best bet.

Parallel modules is what first led me to the SimpBMS. The cost to go with an Orion BMS would have been $2400 since I would have needed 2x 30s BMSes (one for each parallel string, my modules are arranged 5s2p).

I sell them on eBay: SimpBMS Tesla BMS For Tesla Model S/X Battery Modules | eBay
Thanks for your feedback ReiderM!

Do you have a wiring diagram showing how things work in a serial + parallel configuration?

I also would like to know if anyone knows how does the Hyper9 X1 behave with 90v nominal voltage, I hope it's not too short (The hyper9 documentation says nominal voltage is 100v).
 

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Thanks for your feedback ReiderM!

Do you have a wiring diagram showing how things work in a serial + parallel configuration?

I also would like to know if anyone knows how does the Hyper9 X1 behave with 90v nominal voltage, I hope it's not too short (The hyper9 documentation says nominal voltage is 100v).
The wiring is the same for any series or parallel configuration. The balance boards just need to be told what to do to each individual cell, and all balance boards are given the same command for any series/parallel array.

90v nominal is low for the Hyper9. It'll work fine (minimum voltage is 62v), but you're losing out on power. At a lower voltage, the motor will take longer to spin up to speed. I'd highly recommend you take the voltage as close to the maximum allowed by the X1 controller as possible.
 

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I also would like to know if anyone knows how does the Hyper9 X1 behave with 90v nominal voltage, I hope it's not too short (The hyper9 documentation says nominal voltage is 100v).
NetGain publishes performance data at several voltages.

Here are the peak power values and speeds of peak torque from the published peak performance charts for the regular HyPer 9 system, with the voltage values linked to the online performance chart document:
SystemDC Link test voltage
V
peak mechanical power
kW
max torque (~230 Nm) up to about...
(RPM)
HyPer 97260.32100
HyPer 98471.42400
HyPer 99681.32600
HyPer 910893.93500
HyPer 9120102.83700
HyPer 9132112.84500

Obviously, more battery voltage is better, but if 75 kW and peak torque sustained up to about 2600 RPM is adequate, 90 volts will do.
 

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The wiring is the same for any series or parallel configuration. The balance boards just need to be told what to do to each individual cell, and all balance boards are given the same command for any series/parallel array.

90v nominal is low for the Hyper9. It'll work fine (minimum voltage is 62v), but you're losing out on power. At a lower voltage, the motor will take longer to spin up to speed. I'd highly recommend you take the voltage as close to the maximum allowed by the X1 controller as possible.
Cool, Thanks! I will order one for the i3 batteries!
 

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NetGain publishes performance data at several voltages.

Here are the peak power values and speeds of peak torque from the published peak performance charts for the regular HyPer 9 system, with the voltage values linked to the online performance chart document:
SystemDC Link test voltage
V
peak mechanical power
kW
max torque (~230 Nm) up to about...
(RPM)
HyPer 97260.32100
HyPer 98471.42400
HyPer 99681.32600
HyPer 910893.93500
HyPer 9120102.83700
HyPer 9132112.84500

Obviously, more battery voltage is better, but if 75 kW and peak torque sustained up to about 2600 RPM is adequate, 90 volts will do.
Thanks Brian, that's very helpful. 75 kW could be enough but I can also try to build a pack with 2 groups of 3 modules in series and reach 135V. Hyper 9 HV could be a better fit. At peak voltage, 3 modules will generate approx 150v and will burn the X1 controller.
 

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I will see if I can get hold of Netgain on the phone and/or try to run some diagnostics on the car. The controller will output 'DC bus' current and 'Motor phase current' via CAN, alledgedly, so I'll see if I can monitor those.
Update: I spoke to Hunter at Netgain, he confirmed that the Motor Current Limit Current map (that refers to 100% current being 750 A RMS) is motor current, and that it is RMS. Fine.

I then drove around for a short while logging 'DC Bus Voltage', 'DC Bus Current', 'Inverter 1 Current' and 'Phase Voltage' from the X1. I also tried watching the Actual Current as shown in the Motor Current Limit Map, and I can confirm that the Actual Current is the same field as 'Inverter 1 Current' as logged.

Traffic was bad, and I couldn't get over 20mph so never pushed the system hard, but it's clear that the DC current was always much less that the AC motor current. Phase voltage was much lower than pack voltage. I don't know what its maximum value is - maybe 100V in the low-voltage Hyper 9?, which would make some sense (100V x 750A = 75KW, about right).

I calc'd DC power vs AC power (using the phase voltage) and these are directly correlated but the AC power was only about 66% of the DC power, which I put down to the motor operating at low motor speeds (<1500 rpm). The highest AC current I could pull was about 600A rms in the motor whereas I never really got over 200A DC bus current. My ammeter, running off a shunt, looked consistently a bit higher than the DC bus current by eye but hard to tell as it wasn't being logged.

I don't know enough about the inner workings of these motors to know what happens when the AC current is up at the 750A rms 'limit' - presumably the phase voltage increases as motor speed increases.

But the long and the short of it is that yes, the Motor Current Limit Map can be used to set a maximum current, but I am really not sure how to link that value back to my DC pack current!

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Rectangle Slope Font Plot Parallel

Controller voltage (rms) shown on left scale, DC voltage on right scale.
 

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Update: I spoke to Hunter at Netgain, he confirmed that the Motor Current Limit Current map (that refers to 100% current being 750 A RMS) is motor current, and that it is RMS.
So the 100% on the map is the S2-2min limit... which doesn't make a lot of sense unless much more than 100% is permitted, because for a shorter duration higher current is acceptable.

I have a more complete analysis of where this value comes from, but have not had a chance to post it yet... I'll add it after this post.

Traffic was bad, and I couldn't get over 20mph so never pushed the system hard, but it's clear that the DC current was always much less that the AC motor current. Phase voltage was much lower than pack voltage. I don't know what its maximum value is - maybe 100V in the low-voltage Hyper 9?, which would make some sense (100V x 750A = 75KW, about right).
Yes, a motor controller is reducing voltage and increasing current proportionally, unless it is at "full on". The spec sheets published by Dana TM4 list the AC output voltage for two DC voltage inputs as:
3 x 0…47 (@80 VDC)​
3 x 0…53 (@100 VDC)​
Output would be higher for the controller which is capable of handling higher input voltage,but in any case the (RMS) output voltage is no more than not much over half of the input DC voltage.

I don't know enough about the inner workings of these motors to know what happens when the AC current is up at the 750A rms 'limit' - presumably the phase voltage increases as motor speed increases.
Regardless of whether or not current is at a limit, the voltage to the motor must increase with motor speed (to overcome back-EMF), and with current (to overcome winding resistance).

View attachment 123967
Controller voltage (rms) shown on left scale, DC voltage on right scale.
It's amusing how nicely the drop (or "sag") in DC voltage reflects the phase voltage; it would be even closer to reflecting DC power. Fortunately, the DC voltage drops only a few percent even in when most heavily loaded.
 

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The way it is given on the NetGain motor page for the HyPer 9 IS, the 750 A looks like a battery current peak, because it is given with battery voltages. That is not the same as motor current, and it is not apparent where NetGain got this value.
Update: I spoke to Hunter at Netgain, he confirmed that the Motor Current Limit Current map (that refers to 100% current being 750 A RMS) is motor current, and that it is RMS.
It looks like there may be a source for those values…

The HyPer 9 components are from SME, which is now part of Dana TM4. The user manuals published by NetGain for the two controllers (to go with the standard and HV motors) are branded both SME and NetGain:

The Dana TM4 web pages for most of their motors - including these ones - don’t provide or link to any detailed specifications; however, there is a TM4 Tautronic™ page, and while it has few specs a web search discovered a spec sheet. The web page shows three product groups, and both controllers for the HyPer 9 would be in the “ACX1 / ACX1-l” group. The Dana TM4 spec sheet shows individual models, and two match NetGain’s controller models:
  1. TM4 Tautronic AC-X1 Low-Voltage Inverter
    • 80 - 100 V nominal input voltage
    • “Nom. current S2- 2 min (Arms)”: various values (depending on model) up to 750 A
    • AC-X1 80/100V 750A SWS is the 750 A model (part number ACX1S75000000)
    • this is apparently what NetGain sells as the regular “AC-X1” for the regular-voltage motor; this model name best matches the highest-current model in the chart in the NetGain manual
  2. TM4 TautronicTM AC-X1-I with Isolated Logic High Performance Low-Voltage Inverters
    • 80 - 100 V or 120 - 144 V nominal input voltage
    • “Nom. current S2- 2 min (Arms)”: various values (depending on model) up to 750 A
    • AC-X1 120/144V 500A ISWS is the higher-voltage (and 500 A) model (part number ACX1T50000000)
    • this is apparently what NetGain sells as the “AC-X144” for the higher-voltage (HV) motor; the model name matches the chart in the NetGain manual
The isolated-logic version specs include values for 10-second “boost current” for both the 80-100 V models and the 120-144 V model; this current for the nominally (S2-2min) 750 A model is 850 amps, roughly matching NetGain’s published test data for peak output.

So the 750 A and 500 A current values, despite being shown with battery voltages, are likely RMS motor currents for the S2 (short time duty) condition with two-minute duration.
 

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While looking at controller information from Dana TM4, I also reviewed their motor lineup: the HyPer 9 is one of the models in their SRI 200 series. I haven't found detailed specs for models within that series yet, so I don't know which one it is, but it appears to be a high-power variant.

The other "ASY" (asynchronous, meaning induction), "SYR" (synchronous reluctance), and "SRI" (synchronous reluctance / interior permanent magnet) series also appear to be from SME.

The IPM 120 and IPM 200 series are from AshWoods, which was also acquired by Dana TM4. Most of the motors from TM4 show up only in the product web page for "systems", not "motors".
 
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