Automated startup of home-built EV VFD

Continuing development of my 3-phase motor controller. I have put all the core components on a single board and that into a proper electrical enclosure for more safety. (see previous video for the hacked up computer case the and desk-mounted controller boards).

Capacitor precharge is now automated. The controller activates when it detects a that the capacitor charge is within 1v of the battery voltage.

In the video, I have the "ignition" turned on to start and the "battery" (simulated by the rectified output of a 300w inverter) switched on later. This is not the sequence that would take place in the car, as the batteries are always "on". The controller works the other way around, but I do it this way so that I can verify other controller parameters before applying high voltage (those hex IGBT modules aren't cheap).

After switching on (connecting) the "battery", I take you through the precharge, contacture closure, and running of the motor. I then demonstrate the low-voltage cut-out (currently set to 150vdc) in which the controller senses a drop in battery voltage and shuts down the controller safely.

Key specifications as run in this video:

Low voltage "battery" supply: 13.8vdc
High voltage "battery" supply: 320vdc
Maximum frequency: 128hz
Motor size: 370w (just for testing, shopping for a larger motor now)

Category:

Science & Technology

Tags:

• electric
• car
• motor
• controller
• vfd
• phase
• ev
• diy
• mauswerkz
• electronics
• mighty
• mods
• vsd
• variable
• frequency
• drive
• speed

[DanFrederiksen]

very nice.

how much DC voltage do you need to properly motivate a given voltage induction motor so it will do that much more power than rated which is what we want for EVs.

I'm still fuzzy on how voltage relates to induction motors. do they have a kind of EMF motor constant like DC motors do?

what voltage is your motor rated at?