I have 2x identical setups having the same problem:
2x Flipsky FSESC 75350 and 2x Flipsky 85165 200KV 8KW continuous 19KW peak BLDC motors running sensorless on 50V, FOC, Current control, 300A limit, 450A ABS Max.
This is a dual outboard boat setup.
Auto-detected FOC values on each:
Setup 1) R 6.4, L 7.59, LQ-LD 0.90, Flux Linkage 5.38, KP 0.0076, KI 6.36, Observer Gain 34.56.
Setup 2) R 6.8, L 7.66, LQ-LD 0.68, Flux Linkage 5.61, KP 0.0077, KI 6.75, Observer Gain 31.79.
Advanced FOC settings (I haven't changed any of these yet):
Zero Vector Fequiency 30khz,
Control sample mode "V0 Only",
Current Sample Mode "Longest Zero Time".
At lower speeds, they run great. At no loads, they run great.
But at higher speeds/loads, I am having the same problem with both setups--
I initially got ABS Over-current faults all the time, even at half Duty Cycle.
Enabling Slow ABS Curent Limit stopped the faults.
Now I am getting UNBALANCED_CURRENTS fault at anything above 80% Duty cycle pulling about 150A Battery (~230A phase).
I logged the last session and it seems the current fluctuates progressively worse as Duty Cycle increases and is jumping around like crazy when Duty Cycle gets into the 70's%. Like from 300A to <200A in less than a second. ERPM is around 35,000 which is 7,00 RPM.
I've attached a couple screencap images of a log of one of the motors running under load and you can see the amps (shown in the graph blue line as Watts power @50V) starts
fluctuating really high in the 60% - 80% Duty Cycle range. I assume it gets so bad above 80% that is throws the unbalanced error. Running below 80% actually feels fine.
https://photos.app.goo.gl/yx2nrhJk29xYLZkE9
Is this normal? Is this normal for a FSESC? ;)
I've run both stock firmware as well as 6.5 (Phase Filters are disabled).
This also happened with a Maytech 120116 200kv BLDC.
I feel like this should be able to be tuned out/down with FOC tweaking, but my learning curve isn't there yet. Any guidance is appreciated, even if it's "get a real VESC!".
Thank you-
Colin