# Diy controller BLDC



## jddcircuit (Mar 18, 2010)

Here is what I am doing.

I bought a gen 1 Prius inverter off ebay for $100. I was able to use it to drive the prius transaxle which is a 3phase permant magnet motor like a BLDC. I used an off the shelf Zilog motor control eval board and wrote my own software. You can use any motor control logic board you want. The prius inverter is a dumb slave and will switch the phases to whatever your control IC tells it to.

I haven't had time to optimize my control algorithm nor have I attempted high power output yet to stress the inverter. So I am not sure what the maximum continuous current is. The prius motor I am using produces a lot of torque at only 200 amps so I am thinking 100 amps continuous will be fine for me. With a 300 volt pack I am dealing with 30kw of continuous power.

It is not a complete solution but it is a big portion of it if you were going to build your own from scratch.

Caution: Do not use the prius inverter if you are planning to go sensorless by syncing to BEMF crossing. The IGBT drivers don't let you have one of the phases floating in order to measure BEMF. You will need to use some type of position feedback, encoder, resolver, or otherwise.

Good luck
Jeff


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## Arlo (Dec 27, 2009)

Thanks for the info. I will most likely use a seonsor type system at least till I get it all build. My plan is to run below 200v so mosfets in the end but I will likely prototype it with igbt's because of cost and I need something that can handle 600 or more amps. The motor I have can handle about 60kw for ten seconds and 30 continous. I will be wanting a system that can put 30 or more kw to the motor. I have pushed the limits of smaller controllers to 200-300 amps at 98 volts but with this motor they blow up when run the hard.


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## Spider-man (May 9, 2011)

This may be a dumb question, but why didn't you use a prius controller? is it too hard to make it ev alone?


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## Arlo (Dec 27, 2009)

Spider-man said:


> This may be a dumb question, but why didn't you use a prius controller? is it too hard to make it ev alone?


 I don't think it will let you program it. So when it is trying to do all kinds of things like run the ICE motor that is no longer hooked to it, it would possibly just freak out as well as not work they way you want. Building a Bldc controller is actually not that hard... Building a Power stage that doesn't blow up and controlling it properly is a little more tricky.


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## Spider-man (May 9, 2011)

Would you have a link to someone who would be able to tell me how to program a controller to work with the prius motor?


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## Arlo (Dec 27, 2009)

Spider-man said:


> Would you have a link to someone who would be able to tell me how to program a controller to work with the prius motor?


 The electric motor or the gas motor? The electric motor is not to hard depending on the controller. Sevcon on a BLDC can be a challange.


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## Spider-man (May 9, 2011)

Arlo said:


> The electric motor or the gas motor? The electric motor is not to hard depending on the controller. Sevcon on a BLDC can be a challange.


The electric motor. 
They run the motor at a very high voltage. (around 300v i think) could you run it at half that and still get the speed you want?


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## Arlo (Dec 27, 2009)

Spider-man said:


> The electric motor.
> They run the motor at a very high voltage. (around 300v i think) could you run it at half that and still get the speed you want?


 I'm actually building a bike. I have a motor with 9 mOhms resistance and 8.5uH inductance its a BLDC 20 magnet 18 tooth 11lb monster and its liquid cooled. So I am working on a controller from scratch because 1000 or more is to expensive for a guess at a controller that will run it!


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## Spider-man (May 9, 2011)

Arlo said:


> I'm actually building a bike. I have a motor with 9 mOhms resistance and 8.5uH inductance its a BLDC 20 magnet 18 tooth 11lb monster and its liquid cooled. So I am working on a controller from scratch because 1000 or more is to expensive for a guess at a controller that will run it!


That is my primary concern with controllers as well. I hear so much about them not always being as reliable as they should and how the customer service sucks so bad with a lot of the companies as well.

I just wish I was smart enough to build my own controller...


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## Arlo (Dec 27, 2009)

Spider-man said:


> That is my primary concern with controllers as well. I hear so much about them not always being as reliable as they should and how the customer service sucks so bad with a lot of the companies as well.
> 
> I just wish I was smart enough to build my own controller...


 You are just use the internet to lern


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## Salty9 (Jul 13, 2009)

Arlo,

Did you find http://www.diyelectriccar.com/forums/showthread.php?t=23799&highlight=alternator+controller?


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## Arlo (Dec 27, 2009)

Thanks its interesting. I will post more soon but I have order most the parts to do this. Incl a PICKIT3 and Im going to lern to program microchips!


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## DJBecker (Nov 3, 2010)

Arlo said:


> Thanks its interesting. I will post more soon but I have order most the parts to do this. Incl a PICKIT3 and Im going to lern to program microchips!


Uhhhggg, the ugliest of the microcontrollers. The only advantage the PIC has is that you can get them in DIP packages. 

The AVR is easier learn, has great hardware support, and good C compilers. The Arduino system has inspired a wide variety of inexpensive prototype boards.

The various ARM processors are a huge step forward. The ARM core is 32 bits, fast, easy to compile for and has very few quirks. I've been using the STM32F100 series controllers. They has many sophisticated timers, can remap outputs to different pins, and have up to 3 A/D converters that can run at a million samples per second each. And since the "VLDiscovery" board is only $10, there isn't a economic reason to use the older processors.


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