Always have a Shut Down Button

This weekend during build day we got a ton done! Battery was put together, we cleaned the lab, the controls group tested their code, but most importantly we got the engine running! Here are a few videos for your enjoyment!

As you can see, Andrew (our Internal Combustion Engine lead) was very happy 🙂

Here we decided to try out the throttle and you’ll see how it went…

 

Hence the message ALWAYS have a shut down button on your bench tests! Overall an exciting day and with spring break coming up we’ve got a TON going on! More for you to come.

 

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We CAN Control the Motor!

See the pun there? As of tonight we have successfully controlled our Emrax 228 motor with CAN signals coming from our hybrid controller! This is huge because it shows our full downwards data pipeline is working. Next step tomorrow is to hook up the web app so we can display this data in real time and meet with our sponsors SunEdison to show them our work!

P.S. Today we also welded some frame members in the chassis to start mounting the motor and engine!

Technical notes:

  • Battery pack we used is 140.2 Volts nominal, controlled with Orion BMS.
  • The BMS and motor controller (BAMOCAR D3) are powered by 12V power supplies limited to 3 and 10 amps respectively.
  • We had to create a precharge circuit that hooks the battery pack to the BAMOCAR. If you hook them up directly you will get a huge surge of current through the controller that can destroy components, the pre charge circuit charges the BAMOCAR gradually. Watch out for the internal circuitry of the BAMOCAR when designing this.
  • If you have questions about programming the BAMOCAR software (NDrive) please contact us at dartmouth.formula.racing@dartmouth.edu. It’s too complicated to put here in this post.
  • The SunEdison board we used to do this does not have CAN ports so we used an Arduino CAN shield from Sparkfun and some RS-485 shields to communicate with the processor through some UARTS.
  • PLEASE do not try this without high voltage training. Notice our safety procedures, clear directions, and clear exit path in case things went wicked wrong.
  • Also note the big red button, ALWAYS have a safety shut down for bench tests!

IT MOVES!

Hello All!

Yesterday we got our Emrax 228 motor running for the first time on the bench. Here’s a video:

For this test we had a 157V power supply to the inputs on the motor controller with a 10 amp current limit. The motor controller itself was powered with 12V and a 3 amp current limit. We used a commissioning manual from online and read the manual MANY, MANY times in order to get it all right. Now we have the resolver working though and full communication to the motor!

Accumulator Coming Together!

We of the ENGS 89/90 “Electric Powertrain” group have been working hard since the fall to get a battery pack worth of the 2016 DFR car together.  When we last checked in on the DFR blog, we had only a very basic idea of what the battery pack might look like, and how it would fit into the chassis.  Well, things have changed, and we’re proud to present the (nearly) complete design of our battery pack!

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A few of the key numbers and features of the pack:

– pack is 300 V @ top of charge
– 5.2 kWh rated capacity
(4.16 kWh per FH rules derating)
– (84) 20 Ah LiFePO4 cells
– 75 kW peak discharge; cts. rating pending tests
– air cooled by (4) 210 CFM, PWM fans
– riveted aluminum container construction
– mica sheet insulation w/o conductive penetrations
– draw latch closure; cells held down by ribs on lid

We are building the first pack prototype now, and we hope to test it by midweek.  Keep your fingers crossed that everything goes well!

– Ben Parker ’16, Battery Pack Technical Lead

Motor Bench Test

This week we built a bench test for the motor and attempted to get it spinning! Sadly it didn’t go through the commissioning process as we had hoped but we’re on it! Debugging is always 90% of the work. We did have fun putting it all together, getting high voltage safety training, and hearing the inverter whine away. For those of you who don’t know we’re working with an Emrax 228 motor and a BAMOCAR D3 controller. Keep watch, for we’ll post a video once we have it running!

hunterAnd Test Bench

emraxTestBench

Here it is in all it’s glory, the emrax 228! Even though it’s made for gliders we’re going to make it work for our car. Here we were hooking it up, trying to phase our resolver.

JankyConnectors

We can’t crimp our Phister connectors without the proper die and huge arbor press (or hydraulic crimper), so this will have to do!