New motor controller brainstorm

[johnrobholmes]

I'm meeting with a factory next week to start engineering a new motor controller. I have my list of features that I want, what kind of features would you want? You can go pie in the sky, but lets try to keep it realistic please.

low price, big size?
high price, small size?
computer programmable?
heads up display?
etc..

 

[nicobie]

Low price, med. size, extra heatsinks

Remote display (like the CA)

adjustable LVC, 36V - 96V

adjustable max current, 20A - 60A continuous (operated from the remote display)

key switch

 

[vanilla ice]

How much $$$ would a (pot? dip?) adjustable LVC or current limit add? Those would be great. Make sure the current limit pot goes to 11..

 

[deardancer3]

Is it possible to make a controller switchable between hall sensored and sensorless?

Can we get some troubleshooting lights/codes for the more common faults, ie bad throttle, LVC tripped, open sensor, winding connection open, etc?

d

 

[johnrobholmes]

Adjustable LVC or amperage won't add much at all. We just need enough I/O ports to get all features working.



I like the keyswitch idea. It would be hard to implement something that wasn't easy to hardwire though. Seems that a hidden switch would do a better job than a keyswitch that is visible. This could be implemented through a shutoff circuit, usable for emergency or turning the system off.

Troubleshooting codes- good idea

Sensored and sensorless- already on the spec sheet. If a hall sensor fails it will automatically switch to sensorless.



This is going to be an EV specific controller, with a rugged extruded heatsink case most likely.

 

[StevenR]

Serial data output to remote device. I am working on an Android application that will incorporate GPS data, battery BMS (cell voltage) data and CA data. If I can avoid using the CA at all, that saves $125.00 that can go into the controller.

 

[AussieJester]

No bigger than a packet of smokes SENSORED adjustable
LVC 100amp continuous lets say 220amp max
and under 200 bucks

May the force be with you johnrobholmes...<--the force is strong in that one

KiM

 

[tostino]

I'd say design it for larger fets than our standard TO-220's. Larger fets handle heat better, and can allow more amperage.

 

[johnrobholmes]

Good suggestions here, they have been added to the sheet.


Size wise, I will make it larger than current RC styles most likely. A pack of smokes isn't enough room for a reliable 100a continuous controller really. Double that, and we are talking. I would rather build it beef to last 50 years + instead of build it light and have it die an early death.


I will be using all surface mount components. I don't have enough money to pay an american to assemble it, and I'm not going to pay somebody in China. USA manufacturing here, 99% pick and placed on the gantry. Not sure what model FETS will be used, depends on a lot of factors including final pricing and power density we settle on.


Keep them flowing guys, even if the idea won't work some golden nugget may come from it. We can get this just right so everybody can have a motor controller capable of going to the grave with you.

 

[julesa]

LEDs displaying hall sensor activation?
Or if it's going to include a display, maybe create a motor wire troubleshooting display mode.

Precharge mechanism for power input capacitors?

 

[AussieJester]

Size wise, I will make it larger than current RC styles most likely. A pack of smokes isn't enough room for a reliable 100a continuous controller really. .

Best tell that too Kelly i have one of theres its same size as a pack of smokes does 120amp constant 200 peak for 3 minutes Going to make something "custom" shoot high why make house brick size controllers for e-bikes like those ridiculous sized inffinion things..

KiM

p.s it also cost under 200 bucks

 

[Ypedal]

water proof ! ( Like submersible proof ! )

fault tolerant ( reverse polarity, shorted motor phase wires, ebrake option for BMS use )

Waterproof.. waterproof....

 

[johnrobholmes]

Best tell that too Kelly i have one of theres its same size as a pack of smokes does 120amp constant 200 peak for 3 minutes Going to make something "custom" shoot high why make house brick size controllers for e-bikes like those ridiculous sized inffinion things..

KiM

p.s it also cost under 200 bucks

What model? This will give good direction of equivalent market. And how big are your smokes down there :lol:

 

[johnrobholmes]

water proof ! ( Like submersible proof ! )

fault tolerant ( reverse polarity, shorted motor phase wires, ebrake option for BMS use )

Waterproof.. waterproof....

double check


The waterproofing will be tricky without just sinking it in epoxy.

 

[MitchJi]

Hi John,

I like really like some of the features in Justin's Controller.

Numbers 1, 2, 3, 6, 7 and 8 all seem very important.
http://endless-sphere.com/forums/viewtopic.php?f=29&t=7134#p107193

1) Programmable limits : All of the controller parameters such as maximum battery current, maximum motor current, low voltage cutoff, max regen voltage etc. can be set to whatever value you like within the limits of the controller. With this 6 mosfet version, the battery current limit can be set from 0 - 30 amps, the motor current limit can be set from 0 - 45 amps.
2) Completely Waterproof: The entire controller is potted in epoxy so there is simply no possibility even of water damage. It can be run entirely submersed, in fact the controller would like that for the great heatsinking.
3) Small Size: This thing is about 1/10th the size of the Crystalyte 35A motor controllers so it can actually mount discretely on the bicycle.
4) Proportional Regen: When the regen switch is activated, then the throttle controls the intensity of the regen braking. The regenerative braking is motor current (hence torque) regulated, and you can set the maximum regen motor current in software.
5) Pulse by Pulse Current Limiting: You can short the output motor leads and run the controller full throttle and not blow a mosfet. Nice feature to have when the axle spins out and severs all the motor leads.
6) Current Throttle: The throttle input directly controls the battery current and hence the vehicle power. If you have the battery current limit programmed to say 20A, and ride half throttle, the controller will deliver 10A of power regardless of your speed.
7) Sensored and Sensorless: If there is a hall cable connected it will run as a sensored motor controller, if there are no hall signals present it operates sensorlessly. If the hall senor was initially connected, and then fails in the middle of your ride, the controller will detect this and switch over to sensorless mode without loosing a beat. I don't really need to say much more for people to know what this means for reliability!
8.) Overtemperature Protection: Rather than shutting down when the controller gets hot and leave you stranded on a hill, the controller automatically scales back the motor current limit value as the heatsink warms up, so it will protect itself from getting too hot while at the same time never cutting out completely.

 

[fechter]

There are some other theads from the past with good lists of desired features.

I'd like to see:

Motor temperature sensing and gradual current limit decrease upon overheat. Same thing could work for controller temperature. None of this sudden cutoff stuff.

Current (torque) control rather than speed control. Use a closed loop current sensing arrangement. Measuring battery current instead of motor current works OK and would also allow output to CA or ammeter, eliminating the need for an external shunt.

Throttle calibration, those chinese hall throttles are not very consistent.

 

[liveforphysics]

I'd say design it for larger fets than our standard TO-220's. Larger fets handle heat better, and can allow more amperage.

OMG yes! TO-220's packages are for gays. TO-247 package at the minimum. It absolutely makes sense from a thermal standpoint, board layout standpoint, package current limitation standpoint. TO-220's are the industry standard for controllers because it enables them to choose FETs to populate the boards that cost $0.20 each, and still have a functional product to sell. Keeping costs to an absolute minimum is the ONLY reason TO-220 fets are used.

For all things 100v and below, this is THE fet. They are <$4 in quantity.

http://www.irf.com/product-info/datasheets/data/irfp4468pbf.pdf

Just 6 of these would make a reliable 150amp 100v controller, which would put the total FET cost at $20-24. Compare this with the cost of 12-18 IRF4110 TO-220 package fets at $20-30, and you can see that for a high current controller application, it's really no more expensive.

 

[MikeB]

Motor temperature sensing and gradual current limit decrease upon overheat. Same thing could work for controller temperature. None of this sudden cutoff stuff.

^ I was just about to suggest exactly this.

It might be nice to implement a state-of-charge fuel gauge output, based on knowing the kWh capacity of the battery, plus current in/out monitoring. Many vehicles are still using a simple volt meter as a fuel gauge, which is quite confusing to most people.

 

[johnrobholmes]

I had some very productive daydreaming and dreaming sessions last night, I think I have the basics down for the 20s 100a version. Some GREAT ideas flowing in this thread.



I will be interested to what the factory has to say about those standup 4468 fets vs surface mount fets.

 

[grindz145]

I would like to see something that computer re-programmable (current limit, LVC ETC) but also OPEN SOURCE with some way for us to go in there and change the code, that would make a winner on this forum I bet.

Also a regulator that will handle 12-100V without adjustments would be great.

Additional feed back would be awesome, its hard to tell whats going on in the controllers now, so a serial output for debugging, monitoring etc would be incredible.

 

[jsplifer]

Ultra Capacitor Regen?

 

[TylerDurden]

Programmable dork-mode: i.e., controller outputs lower power, unless proper input sequence is completed by operator (via buttons/throttle & brake/etc.).

Power-levels and sequences configurable by user.

 

[johnrobholmes]

Programmable dork-mode: i.e., controller outputs lower power, unless proper input sequence is completed by operator (via buttons/throttle & brake/etc.).

Power-levels and sequences configurable by user.

secret decoder ring?

 

[Toorbough ULL-Zeveigh]

will these be sinusoidal or does that go without saying ?
same thing for auto power off time-out if that's not already standard.
+1 for valet mode.

 

[johnrobholmes]

will these be sinusoidal or does that go without saying ?

Thank you for bringing this up. So far I had assumed on block commutation. I have not considered the sine vs block commutation. It would be nice to get rid of the capacitors. I will research the matter.