Detecting ripples when switching ON/OFF bluerobotics thrusters(both T100/T200)

Blue Robotics Products Thrusters and Motors
1

Hi,

I was working on the BlueRobotics T100/T200 thrusters with the BlueRobotics Basic ESC, to study its voltage/current characteristics curves and so hooked it up to a DSO.

I noticed that there are ripples when I switch ON and switch OFF the thrusters. And furthermore, the Ripples are huge when I turn the thrusters OFF.

I would like to know ;

  1. if it is related to back emf or regenerative braking?
  2. how to filter these ripples with any capacitor bank or other solutions?
2

Hi @AbelDavid,

Yes, there will be some power noise from the ESCs, especially when the thrusters are run in air.

  1. Yes, the largest spikes are due to regenerative braking. This cannot be disabled completely without modifying and compiling a custom fork of the BlHeli_S firmware. You can fine more information in this thread, I expand on the explanation in my last post there.
  1. You can use a power filter to attenuate these spikes, a low-pass RC filter is a good place to start.

Normally, these variations are not an issue. Just out of curiosity, what exactly is your application/setup that makes this a concern?

-Adam

3

Hi @adam,

Thank you so much. The systems works fine when thrusters are underwater.(ie less ripples).

The setup was to supply 48V DC from the ground to the ROV having a DC-DC step down converter at a distance of 10m.