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Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Sep 19 2018 7:50am
by oli_b
Hello methods !

Sorry for turning to You directly, but I went through the whole internet and called all possible people but You seem to be the only one in this topic who really knows what he's talking about and digging deep enough...

I have a microcar type "Romet 4E" (You can check it in Google Images as it's most probably unknown to You) that uses a Sevcon Gen4 8035 Size4 controller. (setup is mostly the factory default single-traction-motor, but I could figure out some modding as well, although the flashed-in program is unknown. I contacted the manufacturer but they don't want to disclose information)

Original battery setup was 9pcs 8V 135Ah Lead-Acid, but I converted the car to Lithium (24pcs 3.3V 200Ah LiFePO4) for a much better performance, lower weight, and to extend the EV range to more than twice of the original.
So the system voltage went from nominal 72V to 79.2V (which is no problem for the 8035 as the nominal voltage is 80V and the maximal is 116V as far as I know). I also made some internal mechanical modifications but that's irrelevant at this time.

Now the next step to tune the car further is to extend the speed limit and improve the performance of the regenerative braking.

There are two RPM limits programmed into the controller, the one belongs to the "normal" driving mode, the other to the "economy" mode, which allowes You to drive (through the single fixed gear) 60km/h in normal mode and 40km/h in economy mode.
Certainly I never use the economy mode as it can be achieved by handling the accelerator pedal more gently, I use it for regenerative braking as switching the "eco" mode during driving brakes the car back to 40km/h using regenerative.
So my problem is obvious: 60km/h for normal driving is too slow, and braking back to 40km/h only is too less regenerative braking.
I would like to change the two RPM limits so that the normal limit is 80km/h and the economy limit is 10km/h, not because I want to drive 10km/h but this would allow me to make regenerative braking down to 10km/h instead of 40.
Also the 80km/h has some risk because of the fixed gear, it might over-RPM the engine, so I don't want to drive this speed continouosly, but every now and then there might be a need during overtaking to go faster than 60km/h to make the overtaking shorter.

On the default Gen4 setup there is no "normal mode" and "eco mode", so this must have been programmed by the manufacturer, and I was tracing back the wires and it turned out that the "eco-switch" is connected to "Digital Input #5" (pin 20) of the Gen4 connector: it is floating at high impedance (0.4 x Vbatt) when in "normal mode" and pulled down directly to GND in "eco mode". This pin20 must have been mapped to the "economy" variable inside the controller's program.
So far so good.

Now my idea is to use a ClearView display to program the RPM limit(s) if possible. But before I order such an expensive toy I would like to ask someone with experience (this means You) how the ClearView is working and whether it is possible to program the RPM limit(s) of the motor.
I have seen a YouTube Video ( where some guy was changing the RPM limit of the motor (Menu-->Personalities-->Baseline-->Max Speed FWD), but my controller seems to be programmed to two different limits, and I don't know if it is possible to program more limits with the ClearView? May be this is solved by using the Profiles? (Menu-->Personalities-->Profile1 and Profile2), and the "eco-switch" is just switching between these 2 profiles?
I don't know as the video does not step into the Profiles1 and Profiles2 menu...

The other thing I would like to program with the ClearView is (beside the two RPM limits) is the efficiency of the regenerative braking. At the moment I am not satisfied with the braking power of the regenerative braking.
My suspection is that the "maximum deceleration rate" is limited in the controller, not to overcharge and blow up the original lead-acid batteries, as they can only be charged slowly with a smaller current. But now the car has Lithium that is able to absorb much more power and much more charging current, allowing the car to decelerate much harder, therefore the maximum deceleration rate could be set up for a higher value, so I could brake better with the engine and regenerate more energy instead of using the hydraulic brakes...

So any idea or suggestion or experience is very welcome that helps me further!
Thank You very much! (sorry for writing a complete roman out of it...)

Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Sep 20 2018 8:26am
by sanfox
Hello Oliver!
Can You save your dcf from sevcon and send it for me?
I will try to understand your motor parameters.
Also you has abbility to rise up votage to 100 V an example and take more power from your motor!

Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Sep 26 2018 9:31am
by oli_b
Hello sanfox,

I have no any tools for the Gen4 controller, so I surely can not extract the data out of it...
My questions for the Gen4 in my previous post were to be able to decide if I should buy a ClearView Display, to be able to adjust some parameters.
The Gen4 came pre-programmed by the car manufacturer, who do not produce the car any more, and they refuse any help when I tried to get some over the phone...

Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Sep 28 2018 1:17pm
by sanfox
Oliver, I can give you contacts of a guy from Poland, which has DVT dongle and his oun progect with sevcon powered car.
If you intresting that send me PM.

Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Sep 28 2018 2:24pm
by oli_b
Thank You, it would be very good.
I sent You a PM.


Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Jul 29 2019 12:45pm
Is any one still active on this thread??
I am trying to do a similar project with a Me1114 motor Sevcon Gen 4 size 6 controller
Learning how to this from scratch is not for the faint heartted. Getting no help from Sevcon either.
I try one thing at a time and then re save the dcf file, just to go back if needed.
I have the motor spin for a second and then get an over current error.

Would like to know if the Sevcon Clear View worked out for you project as well. I need to
get a display panel but not sure what one to go with??

Thanks, for any help.. advice..

Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Aug 02 2019 9:20pm
by darseygodwin
Hey Mark,
I'm sure there are many things that could cause your error, but I have been dealing with similar symptoms on a Parker GVM motor (3ph PMAC, sin/cos encoder) and gen4 size 6 controller combo that I've 90% narrowed down to EMI to the motor encoder. While any of the experts can jump in to make corrections, I'll let you know my best recommendation based on what I did SO FAR. Note, I haven't completely fixed my problems so I'm still lurking this page once in a while.

1. Have you done the things in this thread? viewtopic.php?t=88647
Still plenty you can do without an oscilloscope, but it's better if you do have one.

2. Is it under load, or freewheeling in the air? (applying the brakes counts as load).
If it trips while freewheeling in the air - I'm at a loss, that sounds like some bad parameters and you'll need to get the specs from the manufacturer.

3. If its fine when freewheeling, but trips the moment you're under load then you could be in a similar boat to what I had: EMI messing with the encoder values. How do I know? Because I mapped the encoder min and max values to TPDOs, and watched them on my laptop while spinning up the motor. Everything is happy and unchanged until I apply sufficient brakes and throttle (load) to the point where the motor starts to chatter and is about to trip on said Overcurrent fault: and guess what? My peak and trough encoder values spread wider JUST as that happens, when the load cranks up.

Even with Champion EXRAD braided shielded cables, grounding the shielding I still had this problem - but each time I added additional shielding, the problems slowly dissipated (encoder peak/trough values remain unchanged) until more and more amps were flowing. So if you're using unshielded cable (like welding cable) or if you haven't ground your cable shields, then this is at least something to fix. Parker recommended shielding each phase separately, and then the lot of the 3 together, those shields all going to chassis ground. The encoder should be shielded separately, going to a DIFFERENT ground point, and likewise with your traction pack cables being shielded and ground separately from the encoder. Simply having my encoder shield ground on the same chassis point as my 3x AC cables caused all sorts of hell for me as well. I was surprised to learn that.

4. Next, I found that the braided shields inside my 3 phases and DC cables weren't good enough for the level of noise generated, so I wrapped copper shielding tape around the outside of the cables and connected that to the braids, wrapping that with electrical tape. That helped a ton.

5. Finally, it wasn't completely resolved, so the mechanical engineer in me (as in, NOT EE) was questioning how well copper can absorb DC EMI. So I added steel wool to the shielding. It blew my mind, but this actually made a big difference too, the bike even SOUNDS quieter on the road. Tomorrow I'll wrap steel wool on the DC cables (my positive cable is near the encoder cable) to see if that finishes the job. Now, I only start to have these problems when I'm riding over 80 km/hr.

So, hopefully that helps, and if anyone else is reading this and has better advice for me to fix as well, I'd love to hear it!


Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Aug 07 2019 8:53am
by Ming
Excuse me.I am a beginner for sevcon gen4 and now i have met some problems about the Gen4.The first one is the node.The default value of the Node is 11 and 33.But i dont know how,now it just has node 33 and i klick the TPDO/RPDO bottom.It shows nothing but Sync Period without TPDO1,2,3,4,5 and RPDO1,2,3,4,5.I cant change the value of PDOs.Could you answer my question or give me some advise how to learn this software. Thanks a lot.

Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Aug 09 2019 10:37am

Thanks for the information. I have all the shielding grounded but to the same spot on the chassis.
I will repossession it to another ground spot. Makes complete sense that they should be separate and the wires
apart from each other as well. I have a scope but haven't had it out in several years, I guess now is a good time.

I have resorted to paying (OUCH) a tech to help sort the issues. Almost three hours so far. Although the motor
runs well right now it still has a little tweaking to go. Now it is the throttle with the issue, all the RPM's in the first quarter
of travel. I was advised two just use the wiper connection (pin#22) and ground (B-). But it did not work. The Sevcon as
Pin # 34 as power to the pot and it would not work without it. Most likely a software setting issue.

I Should know quite a bit more than when I started, but these controllers have hundreds of different adjustments.
Ming I cant answer your question right now but the tech basically was just playing with different settings till he got it
closer... I cant say it is perfect. I am also a little frustrated he didn't know more than it appeared. I will see about getting
some answers for you. I am paying him by the hour right now so I need to get my issues resolved first.


Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Aug 09 2019 11:53pm
by darseygodwin
Hey Mark! Well hopefully you're making progress at least. I'm sure it'll come out alright in the end of the tech is at least familiar with the sevcon Gen 4.

In the last couple days, I found that my D-axis proportional gain was way too low. As soon as I brought that up, I was able to extract a ton more power, though that power diminishes very quickly. By 90km/hr I'm still at negligible torque before it trips on over-current.

Saying that, I'm just pointing out that I was wrong that it was all EMI. Even now, I still watch the encoder values start to spread when i crank on the torque, so it's not impossible... but with such a dramatic change at lower speeds from just a little Kp adjustment I think it's more to do with tuning again. I managed to use a couple of screenshots from other people's settings that were posted on endless-sphere here to start with, and found a messed up old Brammo dcf file floating around on the internet to try and reverse engineer their motor settings to get an idea how other people tune the D-axis here. If that helps you I can share what I've got but I don't think it's going to do much when you're running a different motor. Good luck!


Re: Sevcon Gen 4 Errors and Solutions thread

Posted: Aug 12 2019 7:04am

Yes, I am using the ME1114 motor platform and the Sevcon Gen 4 size 6 to get what I need done.
At this point I could give others with the same motor/controller number and setting to get them close.
But as I get more into this, ever setup is slightly different. So to be a perfectly tuned motor it needs to be
done on each individual setup.