Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

[jackbauer]

I would say an ABB aluminium frame 2 pole industrial motor would be a good starting point. They can be fitted with a seperate colling fan on the back instead of the shaft driven fan.

[Janis]

Hello, have been out for some time, but I would like to talk about Voltage. For my ev conversion I will go up with voltage as much as possible for start 600V, it is because most what costs in AC is controller AMPS. I will simplify: Let's say we have motor 15kW 4pole 50Hz 230V 52A delta/400V 30A star, and battery pack of 25pc. AGM's 12V 20Ah or pack of 50pc. AGM's 12V 10Ah. The performance, range and weight does not change if we connect motor delta 230V 52A with battery pack 25pc. 12V 20Ah or connect motor star 400V 30A bat pack of 50pc. 12V 10Ah, but changes what, controller AMPS 400V is almost half of what needed for the same 230V , for 400V you can use less mm2 cables, you can use less amps contactors and You have, what is most signifcant, less losses. So 600V and up is preferable and don't forget that you don't need such big amps and Ah for your battery pack as in case with DC system.

[jackbauer]

High voltage brings its own problem such as isolation. Its swings and roundabouts and i'd rather a medium voltage solution myself around the 150v mark but each to his owm.

[Janis]

Both voltages are dangerous 150V and 600V, cable isolation anyway should be rated for 1000V, which major cables are.

[dcb]

Originally Posted by mrbigh

well, the basic of designs are almost the same, these are simple circuits though that need to be scalled up.
I have the same concept in my ManzanitaMicro PFC40 HM AC-DC/DC charger

I'm seeing the boost converters/power factor corrector everywhere now too I'm starting to have faith that they do some good.

Anyone have any ideas how to size the components for the boost converter and the caps on the DC bus? And how to control it?

there is a:

coil: maH and amps

an igbt to charge the coil: amps, volts, (frequency and duty cycle or controller controlls it based on demand or feedback?)?

Large caps to smooth out the DC bus: volts, farads.

Probably a faster small cap too.

So given some parameters, like pack voltage and current, vs motor current (average) is there a procedure for selecting component the boost converter (and controlling it?).

You probably have to size it for a worst case, then turn the igbt booster way down when demand is low. That DOE doc showed it being most active during early acceleration (starting to remind me of the series parallel switch on the white zombie/KillaCycle).

And you have to not overcharge the inductor, cuz that would be inefficient.

So, for example, lets say pack voltage is 100, and can supply up to 400 amps reliably, and you want to throw an average of 200 amps (ignoring conversion losses for a sec) at your igbt array. Also, will the voltage output of the boost converter naturally follow the motor rpm (up to 200volts in this case)?

[dcb]

LOL, I should have read my own reference. What kind of caveman would use an active power factor corrector when there is the Z-source inverter?!?

[NiHaoMike]

I have done some research on the Z source inverter and the main problem is that implementing regen is difficult due to the input diode requirement. A modified design could possibly work, though.

[lapwing]

http://psalserver.tamu.edu/main/pape...i%20Butler.pdf

great thread!

[dcb]

More Z source info
http://www.scipub.org/fulltext/ajas/...01418-1426.pdf

Apparently you control the power factor WITH shoot through (a software problem)! No need for "is it really off?" delays.

Some actual formulas in that pdf

[Nick Nameless]

I just finished reading this thread and I love the idea! If you guys/Paul need help in PIC-programming, let me know.

I need to guide a bachelor-project on PIC-programming next semester, so I need to work me in to the subject anyway...