# looking for a really high voltage motor



## Ziggythewiz (May 16, 2010)

What controller are you using? Most high voltage motors are AC.


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## Siwastaja (Aug 1, 2012)

Your plan sounds ideal for industrial ACIM and VFD. One of the main arguments against them as-is (without rewinding) is the need of high voltage, but if it is exactly what you want... Get a 230V in delta model and you'll get double the nominal power at 700 Vdc.

Do you have plans for a BMS, how about cost of so many cell modules? LiCoO2 (RC polymer pouches) absolutely needs it. They can go to thermal runaway very easily compared to LiFePO4.


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## TheSov (Feb 19, 2013)

Ziggythewiz said:


> What controller are you using? Most high voltage motors are AC.


Im building a PWM based controller with an arduino, fod3181 and some very large mosfets.


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## shortbus (Sep 27, 2011)

TheSov said:


> Im building a PWM based controller with an arduino, fod3181 and some very large mosfets.


You won't be able to drive a very big mosfet with only 0.5A from the Fod3181. At least not if you want your mosfets to live.


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## Siwastaja (Aug 1, 2012)

shortbus said:


> You won't be able to drive a very big mosfet with only 0.5A from the Fod3181. At least not if you want your mosfets to live.


... unless keeping the frequency very low, maybe in the range of a few hundred Hz - max 1 kHz or so. Not the quietest drive, but it could work.


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## TheSov (Feb 19, 2013)

shortbus said:


> You won't be able to drive a very big mosfet with only 0.5A from the Fod3181. At least not if you want your mosfets to live.


????? at 12volts VGS Im pretty sure i can drive about 6 mosfets no problems.


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## DJBecker (Nov 3, 2010)

TheSov said:


> ????? at 12volts VGS Im pretty sure i can drive about 6 mosfets no problems.


Check those calculations again. A 0.5A gate drive is on the weak side to drive even a single big device.


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## Siwastaja (Aug 1, 2012)

TheSov said:


> ????? at 12volts VGS Im pretty sure i can drive about 6 mosfets no problems.


MOSFET gates are not only voltage driven, but also charge driven. Get some basic reading material first!

If/when you are ready to DIY power electronics, modifying a cheap, low-power VFD to use higher power IGBTs would be a fair option for your high-voltage battery pack plan. Many people have done just that.


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## TheSov (Feb 19, 2013)

Siwastaja said:


> MOSFET gates are not only voltage driven, but also charge driven. Get some basic reading material first!
> 
> If/when you are ready to DIY power electronics, modifying a cheap, low-power VFD to use higher power IGBTs would be a fair option for your high-voltage battery pack plan. Many people have done just that.


thanks! I appreciate the help, but id like to stick to DC


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## TEV (Nov 25, 2011)

TheSov said:


> thanks! I appreciate the help, but id like to stick to DC


You may find this information useful :

http://ecomodder.com/wiki/index.php/ReVolt


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## Siwastaja (Aug 1, 2012)

Well, you will have real problems finding a DC motor for 600 - 800 V. There are some, but they are industrial and can be very large and heavy. Say half a ton. Suitable for a train.

You won't probably be using MOSFETs at that voltage and power level either. While it can be an option today, too, usually IGBT's are used instead. Get 1200V modules. They are easily available. And read about gate drive. It's much more complicated than just driving a voltage or using just one driver IC.

The specs you give just do not add up. I'd recommend you two viable options;

1) Build a simple PWM DC controller that works below about 150V, using large MOSFETs. Get a normal EV series wound DC motor.

2) Build a high-voltage system using a modified industrial VFD and industrial ACIM.

Both are relatively same level on the electrical knowledge needed. Since you already have your mind set on high voltage system, I'd pick (2) if I were you; you'd get a fancy AC system with regen, and for very cheap. The reason why people are not doing (2), is because they don't want the pain of high-voltage system and the pain of DIY electronics, but you apparently want to handle both.


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## Matter45 (Jan 2, 2013)

May I ask what the motivation is as to why you want to spend $$$$$ on a complex high voltage system? are you trying to make an electric drag car? And this is your first project?


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## njloof (Nov 21, 2011)

You mentioned motors topping out at 192V on the chart... There are a few DC motors in the 250-288v range (Kostov and Warp)...


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## PStechPaul (May 1, 2012)

High voltage DC motors are available, but mostly very high power versions for mining hoists and rail traction motors. The smallest I found initially are about 60 kW 750V and they go up to 3kV 765 kW:

http://www05.abb.com/global/scot/sc...79810025b514/$file/abb reference list low.pdf

http://www.rigmanufacturing.com/2013/02/15/ge752-series-wound-dc-motor-remanufactured/

Here are some smaller ones:

http://www.safe-way-electric.com/redirect.php?target=catalog&type=dc6

And some really huge motors:

http://www.infomine.com/equipment/listings/details.aspx?equipid=42048

I found some high voltage DC motors on ebay:

http://www.ebay.com/itm/HARLAND-TYPE-E12-DC-MOTOR-200HP-600V-1080RPM-270A-30324-/290668476302

http://www.ebay.com/itm/Baldor-Reliance-RPM-III-30HP-Electric-Motor-1750-RPM-240-V-DC-/180704937498

http://www.ebay.com/itm/New-Baldor-...0-2300-328AT-500V-Arm-300-150-F-/110939750789

http://www.ebay.com/itm/RELIANCE-40HP-DC-MOTOR-C-FACE-1150RPM-500V-ENCL-TEPV-STR-SHUNT-/180954278618

I don't see any reason to use DC motors except for keeping battery pack voltages under 200V. Any higher than that will work for a three phase VFD. When I first became interested in EVs I thought I could make a low voltage AC motor with lots of high current MOSFETs in parallel driven directly from a PIC, but I soon discovered the reason for high current MOSFET and IGBT drivers, as well as the advantages of using higher voltages. And I also researched various types of motors and concluded that ACIMs are the best technology for EVs based on availability, cost, ruggedness, and other factors. And recently I considered using small Li-Ion cells, but the cost of assembly and BMS, and the purchase cost of such cells in terms of $/wH, have convinced me that these small cells are not practical for a DIY project.


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