Search found 253 matches

by devin
17 May 2017, 18:59
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

I'm trying to conceptualize the following: 1) I start with a wye terminated motor. 2) I set the VESC to 120a motor amp limit and 20a battery limit with a 50V pack and 0.06944 ohm winding (0.03472 ohm vesc detected lead to virtual ground point) 3. Full throttle close to standstill, I expect: 1000w = ...
by devin
16 May 2017, 13:00
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

36 volt pack at 100% throttle with a 72volt pack at about 50% throttle and getting the same speed the high voltage system is shown to lose one percent efficiency. @Hummie, please correct me if I am wrong about this, but it seems to me: 72V @ 50% THROTTLE is equivalent to 36V @ 100% THROTTLE in watt...
by devin
14 May 2017, 23:54
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

i'm trying to conceptualize in my mind how sqrt(3) enters into the equation of the difference in kv between wye and delta... this is what flashed into my mind (from geometry) but i still haven't completely solved how it relates: i think the following true, but if my math turns out wrong please let m...
by devin
14 May 2017, 11:15
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

a source i found claims: if 100 turns = delta = 100kv 100 turns = wye = 57.735kv & that this is because: 57.735kv wye x sqrt(3) = 100kv delta & if 100 turns = delta = 100kv 57.735 turns = wye = 100kv & that is because 100 turns delta / sqrt(3) = 57.735 turns wye i can't claim to know if ...
by devin
13 May 2017, 21:21
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

if 100 turns = delta = 100kv

X turns = wye = 100kv

what is X?

if 100 turns = delta = 100kv

100 turns = wye = X kv

what is X?
by devin
13 May 2017, 19:04
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

so in simple terms are you saying there is no "wasted electrical to mechanical efficiency" with delta compared to wye considering there are 3 energized windings at a time with delta and 2 energized windings at a time with wye? in simple terms are you saying all 3 windings are actively cont...
by devin
13 May 2017, 14:00
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

interesting... with delta the use of 2 "underpowered" coils which cancel each other out effectively for motive purposes + 3rd coil which does the "work" results in more total "BEMF per RPM" and therefore higher kv and no load speed (delta) (delta is 1/3rd electrical res...
by devin
13 May 2017, 01:47
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

i think my original guess was wrong about being able to distinguish delta and wye by comparing 1 to 1 and 1 to 2 lead resistance measurements because all 3 windings are energized at the same time with delta... and only 2 at a time with wye... so recalculating... if a lead-to-virtual-ground-point seg...
by devin
12 May 2017, 12:50
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

Benjamin seems to assume that most motors are Y wound. As far as I know, most motors (that we use) are delta-wound. All this does not matter, if I allow you to take (only) external measurements of two motors, one Y wound, one delta-wound you cannot tell which is which. So even when the motor is del...
by devin
11 May 2017, 22:11
Forum: General
Topic: code to change the motor amp limit
Replies: 138
Views: 35005

Re: code to change the motor amp limit

@benjamin... question: if motors are delta wound not wye, does one still need to double the resistance figure of the VESC detection to calculate lead to lead resistance?

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