A few weeks ago I had a long discussion with a journalist from a well know automotive publication who had just completed an in depth review of the latest electric car models from the top manufacturers. We talked about range, power rating, consumption, batteries cell technology and his understanding and knowledge of the technology and various compromises facing the designers in general was pretty good (altho a little too much preaching at the Testla and Elon’s altar). But when I started to ask about motor technology, the conversation just came to a halt. And this has been pretty typical of the interaction I have had with various “experts” in electric car technology recently.
Why? I am not sure. Maybe it’s not as sexy as Lithium Ion 1850 cells, or maybe it’s because Tesla has a “battery day” but not a “motor day”.
When selecting a motor technology for an electric vehicle application, there are a few obvious parameters: weight, power (power density), torque, voltage, cost. But there are a few other parameters that have an impact on the overall product design: maximum rpm (will I need a gearbox?), cooling (will I liquid cooling and all the added costs and complexity?) packaging (will it fit?), efficiency (will I need bigger battery pack?), etc.