# 2 controllers on 1 motor?



## CroDriver (Jan 8, 2009)

Could 2 controllers drive one motor?

This motor ( http://www.kaylorkit.com/mm5.html ) could easily put out over 100kW for a few seconds, but there are no available controllers on the market. 

Could I connect two LogisSystems 156V/1000A controllers to the Kotsov 11" motor?


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## major (Apr 4, 2008)

CroDriver said:


> Could 2 controllers drive one motor?


Hi Cro,

Not likely that you can get that to work. May be technically possible by synchronizing the controllers or adding large inductors between the controllers and motor. Or maybe splitting the field windings of the motor. But, by the time you figured all that out and blew up a couple of controllers in the process, you, or your engineer, could probably have reconstructed the two controllers into one large one. You'd be better off getting 2 half size motors, one for each controller.

Regards,

major


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## CroDriver (Jan 8, 2009)

major said:


> Hi Cro,
> 
> Not likely that you can get that to work. May be technically possible by synchronizing the controllers or adding large inductors between the controllers and motor. Or maybe splitting the field windings of the motor. But, by the time you figured all that out and blew up a couple of controllers in the process, you, or your engineer, could probably have reconstructed the two controllers into one large one. You'd be better off getting 2 half size motors, one for each controller.
> 
> ...


Thank you major!

Do you know what this is? 




*Figure 5: *Dual Controller Assembly


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## DavidDymaxion (Dec 1, 2008)

Careful, that ad is very out-of-date. Search on "Kostov", there are a couple of other threads here about the newer Kostov motors.

Alledgedly the Kostov is not as tolerant of high currents -- putting 2000 Amps of controller on one is asking for trouble. Wayland was running 1200+ when he blew his motor. Rich Rudman said his comm starts to sing at about 800 Amps, so he calls 800 the upper limit.

The newer one is rated for 192 Volts iirc, and Wayland ran a 336 Volt pack. It would probably be better to run higher voltage rather than higher current.


CroDriver said:


> Could 2 controllers drive one motor?
> 
> This motor ( http://www.kaylorkit.com/mm5.html ) could easily put out over 100kW for a few seconds, but there are no available controllers on the market.
> 
> Could I connect two LogisSystems 156V/1000A controllers to the Kotsov 11" motor?


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## major (Apr 4, 2008)

CroDriver said:


> Do you know what this is?
> *Figure 5: *Dual Controller Assembly


Nope,

Never saw that before. You think it actually worked?

They make DC/DC converters which are designed to run in parallel. I've used them. One is the master and the other is a slave. The master has a gate out pin which sends a signal to the slave for synchronization. These are sophisticated high frequency devices designed to handle this mode. I don't think the relatively slow, relatively crude motor controllers will work out so well. But maybe.

Regards,

major


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## AmpEater (Mar 10, 2008)

CroDriver said:


> Thank you major!
> 
> Do you know what this is?
> 
> ...


If you notice, only the inputs are wired in parallel. These controllers are for brushless motors (notice the 3 output terminals)....this setup is not intended to run a single motor, but rather, two independent BLDC motors from one source (perhaps with their throttles in parallel, can't tell from the pic).


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## AmpEater (Mar 10, 2008)

major said:


> Never saw that before. You think it actually worked?
> 
> They make DC/DC converters which are designed to run in parallel. I've used them. One is the master and the other is a slave. The master has a gate out pin which sends a signal to the slave for synchronization. These are sophisticated high frequency devices designed to handle this mode. I don't think the relatively slow, relatively crude motor controllers will work out so well.


You're right, it wouldn't work the way it looks in the pic. 

That is exactly how it would have to work, either that or one main board that can handle multiple power sections which can be "stacked" and run in parallel. There is a company working on this exact concept, "Hot Juice Electric"...the thing is called the "Motor Juicer"....an excerpt from the page:

*"Motor Juicer"* or *"Juicer"* for short
*Motor Control System:*
*System Components: *



[*]One *Juice Brain* microprocessor control unit plus one or more *Juice Plates*.
[*]*Juice Plates *are in the form of a flat plate that "sandwiches" together to multiply current capacity. A system employing more than one *Juice Plate* is known as a *Juicer Sandwich*.
*Design specs: *



[*]Input Voltage range ...................................................... 70 to 500 volts
[*]Max *Juice Plates* per *Juice Brain* (*Juicer Sandwich*).. 12
[*]*Juice Plate* Max Output Current.................................... 500 Amps continuous
[*]Max *Juicer Sandwich* output current (12 *Juice Plates*).. 6,000 Amps continuous
[*]Max *Juicer *system output power................................... 250 KW per *Juice Plate*
[*]Max *Juicer Sandwich* system (12 *Juice Plates*)........... 3 Megawatt

I'm not endorsing this product or company, I just think its a really cool idea and pertains to what your asking about.


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## blackpanther-st (Apr 4, 2009)

CroDriver said:


> Thank you major!
> 
> Do you know what this is?
> 
> ...



That looks like Kelly's own work. they have a similar looking set up to do regen on series motors, using two controlers. one does the field and the other does the armature. they are some how linked to communicate with each other and work in unison. 

the Kellys have some really cool features to them, it's too bad the consensise is that they don't put out what they are rated for. I would certanly buy one if they realy put ot the amperege they rate them for. Mabe in the future they will get it. I plan on writing Kell's rep and pointing out this site to him so he can see what we think of it and what they need to work on if they want us to sieriously consider using their products.


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## 44depot (Jun 19, 2009)

Somehow you can do that


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## blackpanther-st (Apr 4, 2009)

288 Volts !  

What is he using for a motor to handle all that?


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## 44depot (Jun 19, 2009)

blackpanther-st said:


> 288 Volts !
> 
> What is he using for a motor to handle all that?


modified kostov 11"


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## CroDriver (Jan 8, 2009)

44depot said:


>


What car is this?


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## 44depot (Jun 19, 2009)

look at your Private message. "CroDriver"

BTW this is Spyder 550.

http://www.ohler.com/ev/spyder/schematic.html

Sir Ohler sold that car 5 years ago:/ im waiting for saome info from him via e-mail.


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## AmpEater (Mar 10, 2008)

44depot said:


> look at your Private message. "CroDriver"
> 
> BTW this is Spyder 550.
> 
> ...



Think you could share that with us when it arrives? I'm curious how he got that to work


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## Nate (Jul 10, 2008)

*Controllers can be paralled if the internal clocks are synchronized otherwise they would not cycle together. I don’t know of anyone who makes a controller with a clock output and clock input or master/slave set up.*

*The Spyder controllers are synchronized somehow for that circuit to work. They are not typical controllers as I noticed they are "High-Side" driven. The only controller I know of that is a high-side drive is the Zilla. It is totally possible for Otmar to have made a custom pair of controllers with common clock between the two since he designed them. *


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## Tesseract (Sep 27, 2008)

Nate said:


> *Controllers can be paralled if the internal clocks are synchronized otherwise they would not cycle together. I don’t know of anyone who makes a controller with a clock output and clock input or master/slave set up.*


It's more complicated than that. Theoretically, all it takes is synchronizing the clocks, but practically speaking you have to take into account the same bunch of parameters as when paralleling power devices inside the controller, except that the parasitics (especially inductance) are much worse and no longer under your control (e.g. - the distance the two controllers are separated).

If the controllers are current sourcing - i.e., they have a large inductance in series with their outputs - then paralleling multiple controllers is no problem (unless they go to 100% duty cycle... then you better hope the series resistance of the inductors is enough to enforce balancing).




Nate said:


> *The Spyder controllers are synchronized somehow for that circuit to work. They are not typical controllers as I noticed they are "High-Side" driven. The only controller I know of that is a high-side drive is the Zilla. It is totally possible for Otmar to have made a custom pair of controllers with common clock between the two since he designed them. *


The controllers in the Spyder pictures were "T-Rex" models made by DC Power Systems (now defunct). They weren't designed by Otmar, they were his competitors. Here's the archived web page for them:

http://web.archive.org/web/20040605230006/dcpowersystems.com/t1200fly.htm


High side drive has nothing to with parallelability. All it means is that the "load" (motor) is connected from switch "output" (e.g. - source or emitter terminal) to ground.


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## Nate (Jul 10, 2008)

*Conceptually controllers are very simple, in reality they are quite difficult due to high voltages that are generated from inductance. I do agree that paralleling would amplify these already known issues.*

*I heard about Power Systems once on the web but never saw them wired.*

*The high-side was something I noticed when I ran the current path of the Spyder wiring and knew this was not typical; I should have noted to readers that this had nothing to do with the topic of paralleled controllers. Thanks Tesseract.*

*Also to readers, you can't wire just any controller as a high-side drive.*


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