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VESC design specification, manual

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velolac
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VESC Original
Joined: 2019-11-03 09:57
Posts: 6
VESC design specification, manual

Hello Everyone,

I see great potential in VESC project, so I have bought a VESC6+ from Trampa for my custom ebike project. I am a mechanical engineer, so I have basic understanding but it is rather limited in electronics and controlling. I have some questions in my mind that may help other as well.

- Power. My 6+ was rated on the site as 80A continuous. MkIII is described now as up to 100A cont. Was there any power related upgrade, or simply there is more trust in the system as it is now more and more tested? In the tool 100A motor current is allowed, so is it safe for the VESC to use it with 100A? If it is allowed with normal FW why isn't/wasn't described as 100A ESC? Correct me if I am wrong but isn't the accumulating heat is the main limiting factor? Isn't the built in temperature monitoring safe enough to let the temperature decide what is allowed? I understand that people maybe limited by their motors and want them to be safe, but for me it is not the case now with the wizard calculated 86A limit and cold outside.

- ERPM limit: a small description would be nice, to clarify this equals to motor rpm*motor pole pairs (so pole number/2). I have read that 150k erpm is possible with current hardware (60). Is it safe to increase it from the default 100k to like 140k? It seems my two stage reduction for my 530kV, 14 pole motor requires higher rev limit as I reach around 42km/h the motor produces strange noises and gives the feeling like it is limiting current violently (even though I have left erpm limit start at 80%). I use FOC, 12S liion. This question also relates to power, as maximum allowed rpm directly determines the maximum usable output power (W) of VESC. Strange thing is, that once I was assisted to 47km/h on a slight slope, so I am not completely sure whats the case.

- Cable connections: I could not find any info in the manual on what connector I should buy if I would like to use ADC input. Finally found it in the forums somewhere that it is JST PH2. Would be nice if this info would be included.

- Bluetooth module (somewhat offtopic): I have bought it to be able to see and log the system on the go, however it turned out that I need the same VCC and GND pins for BLE and ADC input. Am I correct that I need to simply divide GND and VCC cable to be able to use them simultaneously?

- No load power consumption: I see in the tool that it is possible to add notes for a given setup/motor. Isn't a no load duty sweep test - current consumption measurement could be used to evaluate a motor bearings/losses? Maybe my motor is not the best, but is it normal if it can eat several hundred W without any load, or is it a working stage where sensorless FOC control is not efficient at all?

Thank you in advance, and have a Happy New Year!

velolac

 

velolac
Offline
Last seen: 1 month 2 days ago
VESC Original
Joined: 2019-11-03 09:57
Posts: 6

Since then I was able to capture the problem in the tool. The wobbling and noise it makes at high speed sometimes gives abs max amperage fault (set to 150A by wizard). The curve below was produced with wheel in air.

One of the wizzard results for my setup (Assault 700 motor).



Motor curr A 84,4
motor R mohm 8,4
motor L mikroH 1,91
motor flux link mWb 2,1
     
current kp - 0,0019
curr ki - 8,42
obs gain -

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