Published on October 2nd, 2016 | by James Ayre0
Atieva’s Edna Races Again Following An Upgrade … 0–60 MPH In 2.74 Seconds
October 2nd, 2016 by James Ayre
Atieva’s electric super van Edna, used for testing of the company’s various electric vehicle technologies, has demonstrated its abilities a number of times over the past few years.
Every upgrade that Atieva has performed has of course improved things notably. The latest was the inclusion of a new inverter design (Inverter 3.0), which allowed for a 0–60 mph time of 2.74 seconds.
Here’s more on that:
Last week we took Edna back to a closed course for testing along with a few of the people that raised their hands after the last blog. The purpose of this trip to the airfield was to test our newest inverter design (Inverter 3.0), recently installed in Edna. For those not familiar with the technology, a drive inverter at its core consists of a series of switches that convert the direct current (DC) stored in the battery into alternating current (AC) and send the electricity to the three phases of the AC induction motors in Edna. Inverter 3.0, besides being packaged much more efficiently than Inverter 2.0, is capable of transmitting 700 Nm (516 lb. ft.) of torque to the rear motor in Edna (vs. 600 Nm for 2.0).
We have been testing Inverter 3.0 for a few weeks using the powertrain dynamometers that we have built in our powertrain lab, but real-world testing was needed to confirm the behaviors on the dynamometer. Lab testing is an important step in the validation process, but real-world testing is often the only way to uncover areas that need further development.
Inverter 3.0 proved its advantage. Edna performed a 0-60 mph run in 2.74 seconds, a 0.2 second improvement over the last test. 700 Nm of torque was in fact delivered to the rear motor at the start and Edna was visibly faster than previous tests at the start of the run.
Notably, the testing apparently uncovered a fault that needs to be addressed in the control software — a control algorithm needs to be better tuned, so that Edna’s 1/4 mile time is actually an improvement over Inverter 2.0.
Also, notably, Atieva expects this to be the last “significant” upgrade to Edna, though “continued adjustments” are inevitable. The Alpha sedan prototypes will be here soon enough to take over for most testing purposes.