First run of home-built Variable Frequency Drive (VFD)

Shown here is a 3-phase variable frequency drive of my own design. This is the first run of it so everything is spread out. It will be installed in the case seen in the video for further development. The project will eventually be a full-featured motor controller for electric vehicles.

Seen in the video:
Motor, case (with capacitors inside and precharge resistor), IGBT module, gate drive power supply and optoisolator board, barebones controller IC.

First I turn on the power supply with the charge/run switch in the "charge" position. This allows the capacitors to charge through a 50-ohm resistor to prevent high currents at switch-on. Once the capacitors are charged, I switch the charge/run switch to run, which connects the capacitors directly to the rectifier.

I then turn on the control power which drives the brain board and gate drive power supply. I activate the brain board and the motor can be seen spinning at 1hz. I ramp up the frequency, then down again, and turn everything off.

Development will continue on this project.

Category:

Science & Technology

Tags:

• vfd
• EV
• DIY
• electric
• car
• motor
• controller

[paytontech]

Cool! What's your input voltage and the running voltage of your motor? What's the power rating of the motor?

I think that circuit needs MOAR capictor! :-) Joking of course. What are the rating of those?

[AudiMouse]

@paytontech Input it rectified 240V so 320VDC or so. The motor is only a 370W motor, but that's just for testing that the commutation is working correctly at full voltage.

The capacitors are 2400uF 450V each, two of them.

That said, this setup has been disassembled and is currently being rebuilt in a safer, more proper enclosure with a smarter brain.

[paytontech]

@AudiMouse Nice work. What's your source voltage from the wall plug?

[AudiMouse]

@paytontech 240VAC here in Australia. At my house at least ;-)

[Iseekoutthetruth]

how is your electric mazda doing?

[AudiMouse]

@Iseekoutthetruth The Mazda was sold quite a while back as I have relocated overseas. Continuing development here though.

[paytontech]

@AudiMouse Can't wait to see what you come up with.

[billhac]

@mauswerkz

thanks

[mauswerkz]

@billhac The IGBT gate drive circuit I used on that controller was not very good. It's been superseded several times now. There's a really good driver circuit in Powerex Application note BG2B. Google "powerex bg2b" and it's the first result. Good luck!

[billhac]

do you have the circuit for the driver board from the rx7 controller. iv built several igbt controllers and just want to use the best control circuit to drive the igbts.