Tesla Motors: Battery Engineering Design Intern
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Starting in June of 2010, I worked as a Design Engineering Intern for Tesla Motors on the Model-S Battery Engineering Team. During the six months that I spent there, working both full and part time, my projects included developing a complex MATLAB model to reduce expensive and time consuming battery prototype test cycles, working with suppliers to design and purchase integrated SEMs fasteners for increased manufacturability, and designing assembly-optimized injection molded parts in CATIA. |
High Current MATLAB Thermal Modeling Tool
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As my first assignment at Tesla, I was asked to develop a thermal modeling tool to reliably predict heating behaviors that would allow the company to identify heating problems in the Model-S battery pack ahead of time.
I created a MATLAB model that utilized established heat transfer equations in order to model the heat generation and heat flow in and out of dozens of electrical components. I also conducted tests on existing prototypes to find experimental calibrations that would allow the model to make accurate predictions. Ultimately I arrived at a model that could accurately predict steady state temperatures across the assembly and could be configured and run in the course of a single afternoon by other Tesla design engineers using an Excel based input method. The model immediately caught an incorrect heating assumption that could have persisted undiscovered through several further rounds of iteration before requiring costly redesign to fix it; because the model operated on actual physical principles it allowed future designers to fully understand the cause of this problem and account for it going forward. |
 Model S Battery Pack |
Injection Molded Insulator Design
During my time there I was also asked to help design a low cost, easily installable insulator to cover some electrical components on the Model S.
I selected a two-component injection molded design that met all of our unique requirements and developed both parts in CATIA using snap fits and aligning features to meet the strict packaging constraints of nearby components; the final implementation required only a single pull mold action to keep costs down.
In the end, my design replaced previous concepts which had included up to twelve separate components with four injection molded pieces that could be installed in under 5 seconds.
Integrated Fastener Design
 Example of SEMs Fasteners |
On another project, I was asked to work with fastener suppliers to develop an integrated SEMs fastener solution to aid in manufacturability of the battery packs.
In order to fully understand the complex electrical and mechanical joints involved, I conducted literature and experimental research to develop a model of the stress, strain, conductivity, and thermal expansion behaviors in each connection. Using this information, I worked with suppliers to develop custom fastener assemblies which were optimized to our specific task. Additionally, I helped manage the selection and procurement of all prototype fasteners for the Model S battery pack. As a result of my work, Tesla is able to replace multi-component nut, washer, and bolt assemblies in the battery pack with preassembled stack-ups that will significantly reduce manufacturing time and labor costs while making improper installation more difficult. |