3 Phase Power

I've been thinking about 3 phase power for the shop today. Last night I saw a nice 3 phase plasma cutter on Craigslist, but like most normal people I don't have three phase power in the shop. As it is going to be a while before I get back to the electric car project, I've been thinking I can use the inverter to make a phase converter. It will basically be a variable frequency drive with a single phase input and a fixed 60 hz output. I think I have everything I need except a couple of contactors, relays to get from the sanguino output to the coil input on the contactors, and some power resistors to use as precharge load. More thoughts to follow.

Side show

If anyone is interested, I am also building a new bed. It's kind of wacky.

Setup of controller

 
Here is a photo of the mounted Sanguino, IGBT's, one of two PWM cards, a breadboard and a 12 volt power supply.
I screwed up one of the PWM cards by installing transistors the wrong way, and then desoldering badly and messing up a trace. Arg.

New arrival

Two PWM driver cards from the Reprap store arrived a couple days ago. I should have a chance to solder them up tonight and see if they do the trick. Now I just need a motor to play with.

Changing the Purpose of this Blog.

As the election is long passed, and I'm back to the regular part of my life, I'm going to start using this to document my attempt to build an electric car. I'll be kluging together all the parts I can scrounge, and recycling or upcylcing at every opportunity. This will be the ultimate cheap skate ride.

Here is the basic idea:

Find an old small light car to convert. I have a friend with a '68 VW beetle who may be interested in donating it to the cause. It's a bit rusty, but I'm a decent welder and the replacement steel is cheap.

Ditch the engine/gas tank and anything else no longer needed, hopefully selling the engine for the cost of the steel repairs.

Find a burnt out 30 to 40 hp squirrel cage AC motor for scrap value. Grind off the cooling fins, weld on a water jacket, fabricate an adapter to the transmission, replace the bearings, and rewind with high quality windings.

Make my own VFD for controlling the motor. I'm going to use a sanguino which I have already bought and built. I'm having to learn how to program it which is very fun. I've bought an encoder off ebay and will be trying to implement some kind of vector control. I like full torque at 0 rpm.

Highish voltage pack. Somewhere around 400V DC. Still trying to figure out what batteries to use. If I can find a sponsor I will try and use lithium. I have no problem plastering the car with some companies logo if it means we can afford a juicy highpower pack. Only issue is lithium needs a much more complex pack controller, and the fact lithium is about 4 times the price of lead. Looking for about a 17 kwh pack which should make for at least an 80km range. More to follow.

Homebuilt progammable charger. I'll likely use a microcontroller, a big IGBT and a welding power supply.

Woot.