Inverter Research: Using a Test Rig to Improve EV Batteries

What do a group of student researchers, thermal response, and MES have in common? They’re all part of a relatively new research project focused on the study of thermal management and predictive modeling to develop better EV batteries for the burgeoning e-Mobility market.

This collaboration between MES and researchers at The Ohio State University is well underway, with lots of progress being made in understanding how to create an effective thermal design; something that, of course, automotive OEMs are in need of.

Here’s a look at the latest in this joint research project; this one involving the development and validation of a test rig that can simulate real-world conditions and enable predictive modeling.

How a Test Rig Can Further Next-Gen Inverter Designs

To test state-of-the-art inverter designs and the packaging approaches used to extract heat from power-dense inverter modules, the capstone student team at The Ohio State University constructed an experimental test rig.

When used with an inverter, the test rig emulates drive cycle electrical loading conditions and records the resulting housing temperatures, enabling the team to identify hot spots. The test rig was specifically designed to be interchangeable; that way it can test a variety of inverter housing specimens and designs.

3. Data collection: Comprised of surface resistant temperature detectors or RTDs, this measures temperature at critical locations while an infrared (IR) camera maps the temperature distribution of the housing during testing. The RTDs connect to a Data Acquisition System, enabling researchers to access the data on a computer for real-time monitoring and analysis.

Real-World Drive Cycle Simulations

Researchers conducted several tests to demonstrate the capabilities of the test rig. For all of tests, the heating elements were calibrated to dissipate less than 50% of the peak inverter load. Why? To mimic as closely as possible the conditions of city drive cycles.

To study the role of the housing in heat dissipation, the team conducted experiments with and without coolant flow.

Here’s what they found in a series of tests that simulated a car stopped/parked after driving:

Success …

The focus of this capstone was on developing a test rig that can provide repeatable experimental results to generate reliable information for predictive modeling. The test rig was a success!

So, the rig will be used for testing a variety of existing and improved housing designs, which will be informed and verified using FEA simulations.

Be sure to check back for me as we provide additional updates on this project and, more importantly, what impact this could have on the electric vehicle industry.