The full version of this article was originally published in Electronic Design October 7, 2013.
By Micheal Austin
The electrical vehicle has been around for more than a century and its most critical subsystem has always been the propulsion system, which includes three main components: a power converter, the propulsion motor and an energy storage system. The latter supplies energy to the electric motor, converting to mechanical energy and traction to the wheels. To most, it has a much simpler name: the Battery.
By: Chris Whaling
This is the first part of a series of articles on the technologies, economics and trends that drive the development of hybrid and all-electric traction drive power electronics. This article provides an overview of traction drive power electronics and forms a basis for future articles on power electronic cost analysis and trends in demand and supply of solid state device technologies for electric traction motor-drive vehicles. Key technical information reported in these articles was developed during the course of research projects funded by the U.S. Department of Energy (DOE), Vehicle Technologies Office. The author specifically thanks Steven Boyd and Susan Rogers, Technology Development Managers for Power Electronics and Electric Motors, at the Vehicle Technologies Office, within the Energy Efficiency and Renewable Energy (EERE) Program at the U.S. DOE for permission to publish information here.
Historically, electric power has been used in vehicles for electric accessories, such as power windows, entertainment systems, dashboard instruments, air conditioning, seat-heaters, and other accessories. Today, cars are being manufactured that use electric power not only for electric accessories but also for propulsion systems. Such electrified vehicles look quite similar to gasoline-propelled cars but have significant technology and engineering advancements under-the-hood, especially as it relates to power electronics. In an electric-motor-only propelled car, the electrical motors are used to power the wheels and the power for the motors is obtained from batteries. A power electronic device commonly referred to as an inverter is used to convert the DC power from the battery to AC power (at a required voltage and frequency) for the motor. A second inverter may also be used to convert AC from the generator to DC to recharge the batteries through regenerative breaking (called the generator inverter). A converter is part of the traction drive power electronics unit and is used to “step-up” (increase voltage) or “step-down” (decrease voltage) to match the EVs’ high-load or light-load sources.
By Dale Bulla
It was a cool clear morning when my wife and I backed our Nissan Leaf out of our Austin, Texas garage.
Thanks to over night charging with my 240-volt EV charger, my batteries were fully infused. Since my 5.2 kWh solar system produces more electricity than I use, I had enough sunshine for about 88 miles according to my dashboard. Of course, I knew that my ultimate destination was a little over 92 miles away to my friend’s house in San Antonio so a charge along the way would be in order. Like anyone, I don’t want to run close to empty.
By Davide Dall’Olio and Giambattista Gruosso, Senior Member, IEEE
Politecnico di Milano, Dipartimento di Elettronica Informazione e Bioingegneria, p.za Leonardo Da Vinci, n. 32, I20133, Italia
Energy management has become one of the most important features in a hybrid electric vehicle, with the primary goals to reduce pollutant emissions and minimize fuel consumptions. Pollution and traffic have motivated a revolution in the way people think about city transportation. The first measures taken by urban, national and international governments were standards and limitations on vehicle emissions, known as Euro-xxxx (followed by a year number starting from 1992), and limited traffic zones in city centers, such as Congestion Charge in London, Electronic Road Pricing in Singapore, Congestion Tax in Stockholm, and Area C in Milan. These measures have been initiated by European cities to address three different challenges :