[Ace_bridger]

Pictures to accompany the previous post...

[Ace_bridger]

I have a slight concern over the controller and whether it is working correctly.

I did a bench test with no pack voltage applied to the controller just to see if the control board was working correctly. I had it hooked up to a laptop running RTD Explorer and recorded the trace which is attached.

I was getting zero PWM output for zero throttle - perfect. I was also getting the throttle output displayed correctly on RTD. What I'm concerned about was that I was getting maximum PWM output with anything other than zero throttle i.e. any throttle apart from zero would give me max PWM output.

I emailed Paul (& Sabrina), who has been very helpful throughout the build, and he indicated that that was OK, see below.

“The default is throttle proportional to motor current (torque). So, if you give it 50% of full throttle, the PWM duty will be ramped up until the feedback is 50% of max motor amps, which would be 0.50*500 amps = 250 amps. So, in a 24v setup, you will probably see the pwm duty ramp up to 100%, since the motor amps won't make it to 250 from an unloaded motor.”

I'd be interested to know if anyone has any experiences which might help ease me worries about testing the controller and the car and have it run off at max PWM when I tough the throttle.

I will be testing the throttle, controller and motor on the car at 24V before proceeding to 144V!!!

[swoozle]

Originally Posted by Ace_bridger

What I'm concerned about was that I was getting maximum PWM output with anything other than zero throttle i.e. any throttle apart from zero would give me max PWM output.

I had the same experience: PWM ramp to 100% with no load. Sounds like it's performing as expected.

For your 24V testing you can also set the throttle parameters so it will operate at low current levels. I'm able to get steady motor speed in the 50A range on 24V.

[Ace_bridger]

Oh thanks for that Swoozle, that's a load off my mind. I'm hoping to have the prototype hall throttle programmed this week for testing at 24V at the weekend.

Maybe this weekend will see the car move under it's own power!!

Many thanks for your post, it's put my mind at rest somewhat.

Originally Posted by swoozle

I had the same experience: PWM ramp to 100% with no load. Sounds like it's performing as expected.

For your 24V testing you can also set the throttle parameters so it will operate at low current levels. I'm able to get steady motor speed in the 50A range on 24V.

[Ace_bridger]

Well, a milestone reached today!! My wife took the kids for drive so that I could connect up the Penny & Giles hall effect throttle sensor to the controller on the car with two of my Trojan batteries wired in series.

I just connected it all up and it work straight away!! I was a little disappointed as we all love a little bit of fault finding!!

I had the laptop connected running RTD Explorer and recorded some traces.

All of the electrical side worked...although the EV200 main contactor got very very hot...I mean too hot to touch hot. I had the precharge resistor (100R 25W) wires straight across the contactor and that stayed at ambient temperature.

I do have a little mechanical noise like a fan case rubbing at low revs but that goes away once the revs are still quite low.

I thought I could smell burning at one stage but that may have just been me expecting to smell something going wrong!!

I've attached some pics of the traces and of the test because, hay, picture speaks a thousand words...and I don't know a thousand words so here's some pics!! Well chuffed that it worked and that the new hall effect worked straight off with no probs!!

The PWM did go to 100% well before 100% throttle but I think (and may well be wrong) that that will go away once I run at 144V and get some proper current going. Also, the PWM stayed at 100% right down until almost 0% throttle...again, I hope this goes away when I have full pack voltage. Either way, I will check that when I get everything installed during final fit.

Comments on the traces or the hot EV200 are very welcome...and on anything else either.

Just put some homemade wine in the fridge to celebrate later...now I just need to figured out what I'm going to do with the rest of this gloriously sunny day here in the UK!!

[onegreenev]

What kind of current? With low voltage you can reach very high currents at 100%. Looks like you have good sized cables on the contactor.

[Ace_bridger]

Of course, that may be it. I've attached a trace of battery amps but I'm not yet sure of how many amps were running through the contactor.

I'll try and find out from RTD Explorer.

Originally Posted by onegreenev

What kind of current? With low voltage you can reach very high currents at 100%. Looks like you have good sized cables on the contactor.

[skooler]

Great Milestone!

my only thought is either the contactor is faulty or the precharge resister is causing it to warm up?

Not sure though!

Cheers,

Mike

[Ace_bridger]

Cheers Mike,

I do have another EV200 but for the life of me I can't find it. I blame it on the house move!!

I think I'll just monitor it, like Mr Green says when I stick 144V across it the current should drop significantly...although I wasn't running the motor with any load so I would expect the power to have been significant.

Just demonstrated the working motor, throttle and controller to my wife...you can imagine the reaction, "well done love, shall we go inside now?"!! The baby had just made some amazing noises from his nappy so it was probably a good idea.

I just need to solve the strange mechanical 'rubbing' that I'm getting at low revs. Perhaps it will just go away if I ignore it?!

MOT Mike?

Originally Posted by skooler

Great Milestone!

my only thought is either the contactor is faulty or the precharge resister is causing it to warm up?

Not sure though!

Cheers,

Mike

[Ace_bridger]

Originally Posted by onegreenev

What kind of current? With low voltage you can reach very high currents at 100%. Looks like you have good sized cables on the contactor.

They are 35mm^2 in English, 290A continuous.