Sevcon Gen4 troubles

[lechoo93]

Hello,
this is my first topic on this forum so I will introduce myself. My name is Max, and I'm an Mechatronics Engineer living in Poland.

I'm working on my custom 4 wheel EV in my free time. I have bought Sevcon Gen4 size 4 (48V, 275A), Ixxat V2 and the seller provided me an DVT Customer software with license. Yet I have some problems with characterisation of the motor, which is in-wheel chinese BLDC QS Motor 48V, 4000W.
http://www.cnqsmotor.com/en/article_read/Big%20Wheel%20QSMOTOR%2016inch%2017inch%20273%201500w%20-%208000w%20Electric%20Single%20Shaft%20Electric%20Motor%20for%20platform/836.html
Sevcon instruction tells about SCWiz software which provides Self Characterisation. I asked seller for it without any answer. After some research I found it on some website about electric boats. After installation I have problems running it - ScWiz through Ixxat connects to the controller but it immediately disconnets (I can only read pre-op / op state). I know this software isn't supported since 2009, but the China guys doesn't provide any motor parameters(inductance, Voltage constant, Torque constant etc). I tried to measure them but it's wasn't working as I expected.

The question is:
-could anyone give me any tips about self characterisation process? Are there any ways to do it using DVT Customer software?
-does anyone used QS Motors and maybe someone has the parameters of this particular motor?

I would really apprecitate any help

 

[lechoo93]

Also the second "self characterisation" option I found is in DVT but it requires the password. Do you know where can I find that password, to avoid writing it by hand like 0x0001, 0x0002, 0x0003 etc... ?

 

[j bjork]

I dont know the answer, but maybe you can find someting in one of the other sevcon threads?
Like this one:
https://endless-sphere.com/forums/viewtopic.php?f=10&t=36146

I think that there are a pretty long one in the aircraft section too.

 

[lechoo93]

I dont know the answer, but maybe you can find someting in one of the other sevcon threads?
Like this one:
https://endless-sphere.com/forums/viewtopic.php?f=10&t=36146

I think that there are a pretty long one in the aircraft section too.

thank's for your reply. Actually I searched the whole forum, and many links that are supposed to lead to SCWiz software isn't up to date anymore.
I found some errors in my system and I'm working on this actually. For now my main problem is that the vehicle isn't starting smoothly, but very roughly. After start (above 2-3 kmph), it works almost perfectly.

 

[amberwolf]

Sevcon instruction tells about SCWiz software which provides Self Characterisation. I asked seller for it without any answer. After some research I found it on some website about electric boats. After installation I have problems running it - ScWiz through Ixxat connects to the controller but it immediately disconnets (I can only read pre-op / op state).

I don't have any experience with Sevcon programming, so you would have to ask Sevcon directly to be certain, but this section of your SCwiz screenshot

implies that you *have* to use that program button to flash the controller with the firmware necessary to use the SCwiz in order to actually characterize the motor, and then you have to have some other software and firmware to flash the controller back to what it was before in order to use the controller normally. I don't know what other SW & FW you would need, but Sevcon should be able to tell you.

Personally, I think that they should design it so it has two buttons, Program and Revert, so that Program sets it up for characterization and Revert puts it back to what it was before, with no other user action or knowledge required.

Or better yet, just have the ability for the controller to do this work built into it in the first place. :lol:


As far as measuring motor parameters...it takes a fairly expensive test equipment to be able to read the inductance and resistance of the typical motor you'd be driving with one of these. $200 gets you something that can *begin* to read such motors, like the DE-5000
https://www.amazon.com/5000-Handheld-LCR-Meter-accessories/dp/B00S298KJO
but it's not good enough for most of this work, and the price jumps up a lot to the next better steps.

People that design their own controllers tell me that I could measure it in other ways with basic test equipment, but they won't answer me when I ask them *how* to do that, and I have yet to find a useful answer on the rest of the internet about it (almost everything referring to this just says to use the really expensive test equipment that does it for you).

 

[lechoo93]

Sevcon instruction tells about SCWiz software which provides Self Characterisation. I asked seller for it without any answer. After some research I found it on some website about electric boats. After installation I have problems running it - ScWiz through Ixxat connects to the controller but it immediately disconnets (I can only read pre-op / op state).

I don't have any experience with Sevcon programming, so you would have to ask Sevcon directly to be certain, but this section of your SCwiz screenshot
scwiz.png
implies that you *have* to use that program button to flash the controller with the firmware necessary to use the SCwiz in order to actually characterize the motor, and then you have to have some other software and firmware to flash the controller back to what it was before in order to use the controller normally. I don't know what other SW & FW you would need, but Sevcon should be able to tell you.

Personally, I think that they should design it so it has two buttons, Program and Revert, so that Program sets it up for characterization and Revert puts it back to what it was before, with no other user action or knowledge required.

Or better yet, just have the ability for the controller to do this work built into it in the first place. :lol:


As far as measuring motor parameters...it takes a fairly expensive test equipment to be able to read the inductance and resistance of the typical motor you'd be driving with one of these. $200 gets you something that can *begin* to read such motors, like the DE-5000
https://www.amazon.com/5000-Handheld-LCR-Meter-accessories/dp/B00S298KJO
but it's not good enough for most of this work, and the price jumps up a lot to the next better steps.

People that design their own controllers tell me that I could measure it in other ways with basic test equipment, but they won't answer me when I ask them *how* to do that, and I have yet to find a useful answer on the rest of the internet about it (almost everything referring to this just says to use the really expensive test equipment that does it for you).

Thank you very much for your answer actually I'have measured the inductance and Ke for my motor, and they are : Ke = 0,46 (Vrms/(rad/s)) using osciloscope and UNI-T UT602. By measuring it straight i get the result of (56÷74)uH which I must divide by two. But when I put these params to the controller, it's not working as expected - I get much better results when I set Ke and Lh to zero.

 

[flippy]

why not use DVT if you have it and program in the encoder from DVT? seems simpler then dicking around with external software.

 

[djgabriel2004]

Hello,
this is my first topic on this forum so I will introduce myself. My name is Max, and I'm an Mechatronics Engineer living in Poland.

I'm working on my custom 4 wheel EV in my free time. I have bought Sevcon Gen4 size 4 (48V, 275A), Ixxat V2 and the seller provided me an DVT Customer software with license. Yet I have some problems with characterisation of the motor, which is in-wheel chinese BLDC QS Motor 48V, 4000W.
http://www.cnqsmotor.com/en/article_read/Big%20Wheel%20QSMOTOR%2016inch%2017inch%20273%201500w%20-%208000w%20Electric%20Single%20Shaft%20Electric%20Motor%20for%20platform/836.html
Sevcon instruction tells about SCWiz software which provides Self Characterisation. I asked seller for it without any answer. After some research I found it on some website about electric boats. After installation I have problems running it - ScWiz through Ixxat connects to the controller but it immediately disconnets (I can only read pre-op / op state). I know this software isn't supported since 2009, but the China guys doesn't provide any motor parameters(inductance, Voltage constant, Torque constant etc). I tried to measure them but it's wasn't working as I expected.

The question is:
-could anyone give me any tips about self characterisation process? Are there any ways to do it using DVT Customer software?
-does anyone used QS Motors and maybe someone has the parameters of this particular motor?

I would really apprecitate any help

Hi, sorry to hear that, I’m looking for SCwiz would you mind point me in the right direction of where I can download it? I couldn’t find it.

Thank you!!


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