Articles Tagged Electric
Articles tagged "Electric"
When we last discussed motor control on this blog, EP10 was drifting around on the frozen lake in Arvidsjaur, Sweden. At that time (January 2007), we were in the process of co-evaluating Conti-Teves’ ABS system in tandem with Tesla’s motor control. We left the lake thinking highly of the Conti system and moderately pleased with the Roadster’s motor control and traction control algorithms.
Ten years ago when I was driving an EV1, one of the best perks was free parking and charging at LAX. I would pull into one of the EV parking places by Terminal One, plug in, and go on my trip. The charger would turn on right away – typically this would be in the middle of the day – and the battery pack would be fully charged even before my plane had left the ground. When I would return a few days later, typically at night, the battery pack would have partially self-discharged and was cold soaked, having sat for days with the charger connected but off.
When I last posted to this blog in May, the news was a mixed bag. Martin (Founder Martin Eberhard) had just officially revised our range expectations down from 250 miles to greater than 200 miles, but we remained committed to holding the line on 4 second 0-60 mph acceleration and delivering the Tesla Roadster with the performance, handling, looks, and safety of a world-class electric sports car. Now it is September and in the last three weeks we have completed performance and range validation testing of Validation Prototype 1 (VP1 aka “the green car”) in order to verify our Tesla Roadster performance claims. I’m extremely pleased to say that the results are in and our hard work has really paid off!
We get some great questions and comments from the readers of our blogs, and this post takes its title from Brent, who on May 30 wrote:
“ The Roadster’s battery is arguably the most coddled automotive battery in history. It has its own climate control system, several monitoring computers, and perhaps some other mojo 'they' are not telling us. ”
In a battery-powered electric vehicle, regenerative braking (also called regen) is the conversion of the vehicle’s kinetic energy into chemical energy stored in the battery, where it can be used later to drive the vehicle. It is braking because it also serves to slow the vehicle. It is regenerative because the energy is recaptured in the battery where it can be used again.
They call me “the range guy” at Tesla Motors, which is fitting since it’s my job to characterize and improve the driving range of the Tesla Roadster. This means I get to:
- Conduct official range testing according to EPA/CARB procedures,
- Work with our development teams to extract the most miles out of the car,
...and best of all...
- Spend lots of time driving the Engineering Prototypes (EPs) and Validation Prototypes (VPs) to collect data to calibrate our simulation models and understand real-world range.
It’s a dream job, but it also has its challenges.
As you may have read in previous blogs, we recently built our first couple of Validation Prototypes (VPs). These cars represent a significant step forward toward production as they implement numerous corrections to issues discovered during safety and durability testing of the Evaluation Prototypes (EPs), are built from hard-tooled components for all body panels, include production headlights, taillights, and interior components (including much more comfortable seats), and many other subtle changes.
To ensure that the Tesla Roadster is as safe as possible in extreme conditions, we have just finished putting one of our Engineering Prototypes through an extensive test schedule at the Continental Proving Ground in Arvidsjaur, Sweden. The proving ground is in a beautiful location on and around a frozen lake about 60 miles from the Arctic Circle.
Stephen Casner spent 25 years working on protocols and systems for transmission of audio and video over packet networks, starting before the Internet existed and continuing through the Internet Multicast Backbone (MBONE). He was recruited to the Silicon Valley to work with startup Precept Software and its IP/TV product, which was later acquired by Cisco. He is currently a Fellow at Packet Design, working on route analytics, and waiting patiently for his Signature One Hundred number to be called.
I’ve been driving production electric vehicles since November, 1998, when I took delivery of a General Motors EV1. I lost that first-generation EV1 when it was recalled in March 2000, but two months later I was able to lease a Gen 2 EV1 with NiMH batteries. GM pried that one out of my fingers when the three-year lease was up. I managed to continue driving electric by leasing a Ford Ranger EV pickup, but again that was only for a year before it was taken back. Luckily, I was given the opportunity to lease or buy one of the last few 2003 Toyota RAV4-EVs. Given the EV1 lease experience, the choice to purchase was obvious!