DRV8302 Magic Smoke

Report your hardware problems here. Include as many details as possible with pictures to get the best possible help and feedback.
vyckakk
Posts: 5
Joined: 20 Oct 2016, 10:44
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: DRV8302 Magic Smoke

Postby vyckakk » 06 Jan 2017, 10:05

Sorry, motor is 4000 W, it looks like this : https://www.aliexpress.com/item/4000W-1 ... .56.NrRy17

kalvdans
Posts: 1
Joined: 11 Jun 2017, 20:00
Location: Sweden
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: DRV8302 Magic Smoke

Postby kalvdans » 11 Jun 2017, 20:15

My driver also burned today, by merely connecting a fully charged 12s battery pack. The firmware was configured with FOC and ADC current control, but I had it working a few times, both with 6s and 12s, before the magic smoke was released. I bought it from vesc.co.uk, and did not mount any external capacitor. By reading Benjamins answer earlier in this thread, I guess it was the lack of external capacitors that caused a voltage spike. I lack the knowledge of replacing the DRV8302 so is someone wants my broken VESC I can send it!
Attachments
IMG_20170611_214259_small.jpg
IMG_20170611_214259_small.jpg (160.04 KiB) Viewed 1515 times

Der Wichtel
Posts: 2
Joined: 30 Jun 2017, 11:23
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: DRV8302 Magic Smoke

Postby Der Wichtel » 30 Jun 2017, 11:46

I experienced the same problem with FOC, 12S, Hall sensors and 170KV motor. My DRV8302 IC and the diode D4 of the buck converter got damaged.
Luckily, my VESC was connected to the oscilloscope during testing. During braking or regeneration, there is a lot of noise on the power line, even though my wires were very short.
Sometimes the spikes were higher than the diodes breakthrough voltage of 60V. By this the diode shorted and damaged the buck converter in the DRV8302.

So there are several solutions to this problem:
- Keep inductance of the battery wires low. Keep wire length short and zip tie them together to prevent large areas between the two lines
- Add more input capacitors as close to the VESC as possible
- Replace diode D4 with a higher voltage rating schottky diode in order to keep the 5V line stable.

Also this thread seems to be interesting: viewtopic.php?f=15&t=586&start=10

After I replaced the broken parts and added more capacitors everything was below 60V. However I will switch back to BLDC mode because of this:
Interestingly, in BLDC mode the peak values of the noise is less than in FOC mode. The switching in FOC and BLDC is completely different but I guess that somewhere in the position observer or switching part the timings are not precise enough with higher rotation speeds, which causes the motor to get out of sync and creating the voltage spikes.
A low KV motor with more poles have even more effect on this since erpm will rise and the motor gets out of sync faster.
In BLDC mode the switching is much simpler.

rew
Posts: 943
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: DRV8302 Magic Smoke

Postby rew » 01 Jul 2017, 07:47


Der Wichtel
Posts: 2
Joined: 30 Jun 2017, 11:23
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: DRV8302 Magic Smoke

Postby Der Wichtel » 01 Jul 2017, 16:40

Maybe I was a little bit unclear. As you already figured out, usually when semiconductors, such as diodes, fail then they become conductive. Sometimes if the voltage is only applied for very short periode the component can recover. But in my case it failed and broke the DRV8302's buck converter. Since the buck converter is generating the 5V for the board, a diode with higher voltage rating is better suited in a 12S configuration.

rew
Posts: 943
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: DRV8302 Magic Smoke

Postby rew » 01 Jul 2017, 19:13

What is your deduction as to what happens after the diode shorts? Replacing the DRV resurrected the VESC? Then the shorted diode blew out the buck converter die in the DRV and the low voltage part of the system (5V and 3.3V) simply shut down.

I thought you hinted at the 5V rails doing "funny" stuff. In that case you're probably blowing up more than just the DRV.


[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Return to “Hardware Problems”

Who is online

Users browsing this forum: No registered users and 1 guest