Hello,
I am looking for a commercially available VESC type controller for an aero application.
It must be at least 120V and over 25kW.
We experimented with the MGM Compro(not a good experience) and we have two Kelly that runs fine, but we want to explore more options.
It must be a finished product because we can't assemble it ourselves. We have the required knowledge but not the time.
Thanks in advance.
120V is really bad voltage for a controller, since the Mosfets need to be 150V rated and those Mosfets have 3 times the on-resistance compared to 100V Mosftes. So the produce 3 times more heat.
In consequence you need 3 times more Mosfets and a driver chip that can actually switch that many Mosftes reliably. So the controller gets hughe in size and very expensive and is then probably even less capable compared to the 22S variant, since you don't make use of the possible voltage (140V). If yo want to make use of the 140V, in order to compensate Amps by Volts, you run into another issue: 140V DC-DC voltage regulators, stepping down the input voltage for the logic stage 12V, 5V and 3.3V rail, do not exist. So you need a transformer....
TLDR: 22S LiIon is the best voltage you can choose from the controller perspective. The motor doesn't care so much about the voltage difference (22 or 28S), and so does the battery. So with 120V you only accumulate disadvantages for the entire system. The only reason to pick 120V is given when you have no influence on the input voltage and you need to adopt to a given system.
Frank!
Thanks for your very technical reply. It helps a lot.
Now we are kind of stuck with that because we already have the 120V (5,2kWh) battery pack and the motor kv is fix to that (we can rewind it).
For future projects, what 22S VESC based controller are commercially available that can handle over 25kW?
Regards
It's true that building a controller above 90v has a lot of challenges. We've learned it a hard way but after a few years of trial and error, we have a viable design.
It's likely the most compact and lightest design in its class. Here is the relevant thread: https://vesc-project.com/node/1477
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)