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!
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!
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
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!
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.
We can’t crimp our Phister connectors without the proper die and huge arbor press (or hydraulic crimper), so this will have to do!
This past Saturday we had our first “Build Day,” a day where the team gets together and works on the car for 4 hours. We made a lot of progress putting the suspension together, planning the mounting system for the engine and motor, testing the impact attenuator foam (the crush zone), and further designing our grounded low voltage system. The chassis is finally starting to look like a car! The controls team has the hybrid controller taking in data from the motor controller, engine control unit (ECU), and battery management system (BMS) and storing it in a database to be used for powering the motor and logging data. The DFR web app is also on its way with data displaying on the page, but not in real time sadly.
The goal is to have the car basically built by the end of this month so that we can start testing components in February. We’re working hard to make it happen! Here’s some pics from the build day itself:
P.S. If you want to donate some doughnut and coffee money (great motivator!) for our build days please feel free to do so on our website or send us a check at:
Dartmouth Formula Racing
Thayer School of Engineering
14 Engineering Drive
Hanover, NH, 03755
The Emrax 228 has finally arrived from far, far away! This is our first week back on campus and the team is pumped to keep things going. Here’s a pic of Ben and the motor so you can see how glorious (and small) it is.
As you can see there’s lots of activity here at DFR. We’re working on the battery pack, the battery management system, the main controller for the car, the engine, and the chassis! As you saw, we were modifying the chassis up in Canada at VR3 Engineering. They worked with us to complete the job and now we have a beautiful chassis sitting in our lab!
and here’s the old back all chopped off. Sorry DFR 2104 team members 😦
We’ll keep this half to take suspension points off of and help place the shocks for the rear suspension. With the chassis complete we can start mounting the other components in the car!
The engine just came back from BoltonWorks in Connecticut. They did a 3D scan of the engine and created an incredibly detailed SolidWorks model from the point field they got from scanning it. This gives us an exact model to use when building the engine mounts for the car. Getting to see their facilities was a treat! Thanks guys!
On the engine testing front we’ve been in discussion about how best to test our new ECU and engine in the car. We’re discussing a test rig we can hook up to the engine while it’s in the car, more on that later after the holidays.
On the controls side we’ve managed to connect all the electrical components over CAN Bus and obtain data from them on our central controller. We’re storing this data in a SQLite database so we can access it for our control algorithms. Things are really coming along!