Hardware


Ooops. Overshot a bit. Hit 107.00kw today.

Pavement dried out. The acceleration is stretching the front suspension upward
nicely.

98.44kw so far. Getting there. I bet any sagging is caused by the pack.

I’ve got the pack doing better. But now it’s raining. Anywhere from 0-10 mph I
can spin the tires right up in the rain! More testing on dry pavement will force
more current from the system. That will let me know how close to 100kw I am.

Some prototyping netted 91kw of output from my truck recently. The acceleration was unbelievable. That’s still an 80% improvement. The pack is sagging more than normal right now. So I’m correcting that as of now. I suspect that would be worth a few more kw. Looking forward to 100kw soon as the pack gets updated and the R & D progresses.

The data sheets say the factory igbt’s are rated at 400 amps. Almost there now. If I can keep the pack above 250vdc at 400 amps, then I’ll be at 100kw.

I have had an igbt/hv buss redesign going. Might have to put more priority into that since the factory igbt’s are nearly at their max current rating. Although for maybe only 10-15 seconds at a time, 400 amps may not be a threat to their longevity.

With the A123 prototype modules doing fine, a full pack would have such low impedance that 100kw would be easy to hit. Maybe too easy. Going to build about 12 more A123 modules soon.

I found on the Endless Sphere forum a BMS that matches my needs and philosophy of being simple, but with a processor. Here is the link. He talks about his design as he builds it in other threads. I just don’t see anything since late 2009 on the progress of the design. I’ve emailed him. We’ll see.

Here you can see his prototype layed out. It communicates using infrared leds. That helps get around the EMI issue.

Tonight I finally got this system debugged. Turns out it had a bad transformer on phase A. Runs smooth as glass now. I left it outside since it’s so cold here now. This will cold soak the Dolphin and help to test if it’s prone to classic dropouts or not. Cold and humid weather pushes any marginal board right into classic dropout mode. Clunk clunk!

Got another customers board today from Hawaii. It needs the dropout mod and also I’ve been requested to add the 70kw upgrade. Busy weekend.

I have have gathered up all of my individual schematics of the Dolphin system and am drawing them up to make a master schematic.

Since I’ve been hammering away at debugging this east coast system, I built up another system to help me. So now I have another completely assembled system that runs.

I’ve been working like a dog on making an electric vehicle system for a guy on the east coast. It’s been assembled for days. Runs too. But it has this kind of miss to it. Almost like it’s got one bad spark plug wire. It just runs rough. I’ve not seen that kind of problem before with an AC electric vehicle system.

Also have the spot welder nearly assembled. It just needs some finishing. I hope to create a process to spot weld braided flat cable to lithium battery cells. The cable allows flexing without breakage. Mostly for our combat robot buddies. For automotive use it’s not really necessary. But it will be a great process to have under my belt.

After this system gets shipped, I have gathered all of my hand drawn individual schematics, and will create one large schematic for the entire Dolphin main board. I have almost every square inch documented. Just a little remains. But even a mostly completed schematic will be helpful in debugging. I’m still deciding what cad package to use.

Today I just announced the opening of the US Electricar store to the US Electricar Yahoo group.

If you have not noticed or heard, I’ve opened the US Electricar.net store for USE owners so they can get repairs and parts to keep their vehicles running. There are links on this blog to take you there. Enjoy!

It occurred to me today that I could design a dropin replacement for the Dolphin’s filter caps, HV buss, and IGBT hardware under the main board. It would be put together a lot like the ACP cars. Separate igbt’s in parallel for each phase. Several filter caps too. This would make getting parts far easier. There is a a lot of volume to work with under the main board. I’ll have to draw it up in cad sometime to see how it will physically fit. I should dig up the ACP pics I have as well of their hardware.

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