I need some help in setting up VESC in a generator application. Below is a brief description of my setup and findings so far.
I have two motors (one I am using as dyno and other as generator) and both are mechanically coupled together, as shown in the figure. I have a custom build controller running my dyno at desired RPM which I set via UART (LabView application). The other 48V motor (which is being used as generator) is attached with a VESC but there isn't any DC source attached with it. I have only connected a load (~6.6 Ohms) on the DC bus.
The parameters of the 48V (1.5KW) motor which I am using as generator;
Rs = 0.141 Ohms, Ls = 1.05mH and ~15 RPM/V
VESC Tool Setup:-
Motor max. current = 60A; Motor max brake current = -80A Battery max. current = 60A; Battery max regen. current -80A.
The ERPM max I have set is 3600 (200 RPM * 18 pole pairs)
The control type/mode/application is ADC
No DC is connected to VESC, it powers up once the generator starts rotating above 150 RPMs which puts about 14V on the DC bus of VESC.
Results so far:-
I have tried all the control types/applications but only two seem to work; 1) Current Reverse Center 2) Duty Cycle
But in both of them it looks like VESC is not behaving as I expect it to behave. It doesn't brake hard meaning it doesn't give me any decent power/current. In both modes/control types the maximum I get is
18V / -3.8A @ 200 RPM and around 33V / -5A @ 500 RPM
When I move my potentiometer (on ADC1) the values do vary but that's the maximum I get. They don't change no matter what brake (or regen.) current I set.
I have tried to use 'Current No Reverse Brake ADC2' but it doesn't do anything. In the VESC tool the CH2 remains grey. I can see its voltage changing when I move my pot. but it doesn't turn green and hence this mode doesn't work.
-- Current Reverse Center @ 200RPM
-- Duty Cycle @ 200RPM
-- Duty Cycle @ 500RPM
I have even tried changing the IB and HB (after turning off the 'control Type' under 'App Settings') but no matter what value I use the 'I Batt' doesn't change much. It remains between ~-3A to -5A (@200 RPM).
Can someone please shed some light on why it is behaving like this? or What I am doing wrong? and what should be the correct set-up (both hardware and vesc configuration)?
What I want to do is; to vary the generation energy depending on a command from UART or with the help of a potentiometer on the ADC without changing the RPMs.
I would really appreciate a quick reply. Thanks a lot in advance.