Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

sparkey · 05-08-2020, 07:08 PM

Hi all,

I'd like to share my progress on my inverter build. I bought a bare board about 18months ago (yeah, i know), and following the instructables, paul's documents and this thread, I finally have what seems to be a functioning inverter. I've followed Paul's instructions almost to the letter, including which current sensors, capacitors etc to buy, even down to the design of the housing and copper plates. The inverter is tested using every test I've read, and it appears to function correctly!

I've attached some photos.

I'm using a lexus GS450H motor as a test motor, and I'm having trouble getting it to spin using the throttle. This is a permanent magnet motor, with an rx-8 hall-effect throttle, and a 48v (nominal) pack

The main values i'm changing to tune are KP/KI, the throttle values (min, max throttle & regen) and angle-offset. Are there any more that I'm not aware of?

So what am i seeing:

The throttle seems to have no effect, but I can see the raw values change as expected when streaming (values change from ~315 -> ~800). I've tried every combination of throttle settings I can think of, but with no luck.
Running the run-pi-test2 produces inconsistent results: the motor turns briefly (maybe 45 or 90 degrees) when the test is run, and sometimes converges to near 0, but it doesn't converge every time i run it for any settings i use. So when i *think* I've found good values but then it doesn't converge a minute later.
The run-angle-offset-test causes the motor to run smoothly (between angles 140->240), so the inverter is capable of running the motor smoothly. I just cannot make this happen using the throttle.

So my questions:

For a given KI and KP, should I see a response from the throttle, even if it's a small movement of the shaft?
Are KI, KP and angle-offset related to such an extent that they would cause no response from the throttle if it's set up wrong? In other words, which numbers are most important to mess with to verify that I can get ANY response from the throttle.
Is there a test I can run which proves / disproves that throttle response is / is not working?

Sorry for the long post, but this thread has been amazing help, and I hope to contribute in future.

05-08-2020, 07:08 PM	#3410 (permalink)
sparkey EcoModding Lurker Join Date: May 2020 Location: UK Posts: 5 Thanks: 0 Thanked 5 Times in 4 Posts	Introduction and request for help Hi all, I'd like to share my progress on my inverter build. I bought a bare board about 18months ago (yeah, i know), and following the instructables, paul's documents and this thread, I finally have what seems to be a functioning inverter. I've followed Paul's instructions almost to the letter, including which current sensors, capacitors etc to buy, even down to the design of the housing and copper plates. The inverter is tested using every test I've read, and it appears to function correctly! I've attached some photos. I'm using a lexus GS450H motor as a test motor, and I'm having trouble getting it to spin using the throttle. This is a permanent magnet motor, with an rx-8 hall-effect throttle, and a 48v (nominal) pack The main values i'm changing to tune are KP/KI, the throttle values (min, max throttle & regen) and angle-offset. Are there any more that I'm not aware of? So what am i seeing: The throttle seems to have no effect, but I can see the raw values change as expected when streaming (values change from ~315 -> ~800). I've tried every combination of throttle settings I can think of, but with no luck. Running the run-pi-test2 produces inconsistent results: the motor turns briefly (maybe 45 or 90 degrees) when the test is run, and sometimes converges to near 0, but it doesn't converge every time i run it for any settings i use. So when i think I've found good values but then it doesn't converge a minute later. The run-angle-offset-test causes the motor to run smoothly (between angles 140->240), so the inverter is capable of running the motor smoothly. I just cannot make this happen using the throttle. So my questions: For a given KI and KP, should I see a response from the throttle, even if it's a small movement of the shaft? Are KI, KP and angle-offset related to such an extent that they would cause no response from the throttle if it's set up wrong? In other words, which numbers are most important to mess with to verify that I can get ANY response from the throttle. Is there a test I can run which proves / disproves that throttle response is / is not working? Sorry for the long post, but this thread has been amazing help, and I hope to contribute in future. Attached Thumbnails