HEVT Gets an Early Christmas Present

Sometime over this past summer, our vehicle, Mary the Malibu, developed a ground fault that crippled our ability to run in EV (electric vehicle) mode. We spent roughly four months troubleshooting, but we recently received an early Christmas present — a running vehicle!

I repeat: Mary is mobile!

We were able to find an issue with our rear traction motor inverter and have it sent off to UQM for repairs. After getting our inverter back we were able to re-integrate it into our vehicle to use our high voltage system to run the rear traction motor. Being up-and-running again in EV mode is a huge step in the right direction. We'll now be able to do some vehicle testing and collect a lot more data. We'll be using this data to refine our control code and increase EV efficiency.

Where do we go from here? I'm glad you asked!

Our next major milestone is to get our front powertrain working. As discussed in an earlier post, we have been troubleshooting a fluid leak with our P2 generator motor. We have since narrowed down a few options and are collaborating with headlining sponsor GM to see which stock components may be conflicting with our system.

Next step is to validate our engine controls outside the vehicle using an engine test stand. We will first re-wire the engine on the test stand and then verify certain controls. Once we have done that, we can add our P2 to the engine and test that. Finally, we will add our transmission to the mix and test the engine system fully.

Once we can validate our complete engine components, we should be able to re-install our engine into Mary and run our front powertrain. This will give us our as-intended final product — a running series-parallel plug-in hybrid electric vehicle!

Be sure to like us on Facebook and follow us on Twitter for day-today updates and progress.

Have any ideas or advice for vehicle testing? Let us know in the comments below!

Build Update 11.8.13

In Year 1, we designed an ambitious architecture that uses a P2, or position two, generator motor that sits between the engine and the transmission. Working alongside our local sponsor Kollmorgen Corporation, we designed and manufactured this custom generator motor. This, of course, did not come without any complications...

For the past two weeks, we have used Kollmorgen's labs to test the custom generator motor that they built for us. We had originally planned to use this time to iron out control details of the Rinehart inverter that we are pairing with the custom generator. Due to unforeseen circumstances, we are now making sure to test our P2 as much as possible while we have access to Kollmorgen's labs.

Team leader, Eli White, receiving our new P2 generator motor.

We are also validating the operational limits of the generator motor before implementing it into our vehicle. We will be able to take what we've learned while testing the P2 and use it in finalizing the control code and generating electric power to the vehicle. The data collected will be used to validate and improve the vehicle model that we designed in Year 1.

We have really enjoyed the testing time and have learned so much about the operation of our generator and inverter. A big thanks to Kollmorgen for all of their help with testing and thanks to Rinehart for all their help in tuning the inverter to work with our generator!

With Kollmorgen and Rinehart's help, we are making great strides in implementing all of our vehicle's hybrid components and have a bright outlook for Year 3 competition. Be sure to follow along with our process throughout the rest of Year 3 and leave us encouragement and suggestions in the comments below!

Build Update 4.19.13

Last Friday, we received the finalized half shafts for the BorgWarner transmission we are using in the rear of the vehicle. Now that these shafts are the correct length, installation was as simple as sliding the splined shafts into one another.

With these parts installed we are able to mechanically link the transmission to the wheel hubs and drive the vehicle using the rear traction motor. With the addition of the half shafts we were also able to fill the BorgWarner transmission with fluid and assemble the entire rear cradle into the vehicle. This marks a major milestone, as it was the last mechanical driveline component to be installed in the car. Now it's off to the controls and electrical teams for testing and refinement!

Build Update 4.12.13

Last week we returned the P2 motor/generator to team sponsor Kollmorgen to fix fitment issues. Kollmorgen was very quick with the alterations and we received it back the next day.

With the P2 back in the lab, we were able to reassemble the front powertrain. Here’s to hoping the front engine, P2 and transmission assembly never have to come out of the car again! We started with the assembly of the P2 to the transmission by routing the three-phase and signaling wires from the P2 through the transmission and its bell housing. With these two connected, we sealed the P2 coolant fittings and the holes where the wires protruded.

Build Update 3.29.13

This past week we sent team members Tyler Erikson, Danny Keaton, Eli White and Chris Manning to Mississippi State University for the regional safety technical inspection. We were joined at inspection by teams from Mississippi State, Embry-Riddle, North Carolina State and the University of Tennessee-Knoxville.

We received credit for completing the majority of the organizer’s checklist for the inspection. Overall, we were successful and were complemented on various novel and innovative items on the car. Out of the fifteen schools in the competition we are alone of the first teams to close our contactors. However, the organizer’s inspection team did point out a lot of things we need to fix before competition in May.

We have a lot of work to get done before competition like integrating our half shafts and getting the engine to run. After we integrate all of these components we need to test and adjust the control code to make sure everything works. We’ll be working hard to complete all necessary tasks before our send-off event on May 1, 2013.

Build Update (3.1.13)

Randall Morcom and Martin Mock in front of dSPACE headquarters.

This week we focused on the controls system of the vehicle. The controls subteam has been developing the testing structure for the vehicle model and control code. This came to a great success thanks to dSPACE, Inc. Two of our engineers to travel to Wixom, MI for a two-day training course on AutomationDesk. This training allowed the team to automate tests on the vehicle rather than manually testing all of the components. The team has successfully finished testing the EV mode components for faults and is moving toward testing other components of the car such as the brake pedal and engine among other components. Also, we’re currently in the process of switching from Software-in-the-Loop testing to Hardware-in-the-Loop testing. Though we have a long road ahead, the team is extremely proud of its accomplishments this past week! Send us words of encouragement or advice in the comments below, or email us at hevtoutreach@vt.edu.