The content of Copper is rising in EVs. EV makers are looking at employing copper induction motor in an effort to increase the efficiency and performance of their vehicles.

Electric vehicle (EV) popularity is growing in response to rising fuel prices. To be precise, with gas prices surging towards the US$ 4 a gallon mark, and expected to rise further, advanced markets like North America have increasingly started to look at EVs as the mode of transport into the future. The popularity of EVs is good both for the auto industry and the environment. Apart from contributing to a cleaner environment, EVs will also help shed dependency on foreign oil according to Bob Weed, Copper Development Association OEM vice president. He adds, “The use of more electrically-fueled vehicles is good for energy independence, good for the environment and will have a very positive impact on the amount of copper that’s used in a vehicle”.

Weeds’ comment comes at a time when engineers are looking at copper induction motor in an effort to enhance the efficiency and performance of EVs. In the past, internal permanent magnet motors had been one choice for electric vehicles. But that view is evolving as automakers consider the induction motor, a potential alternative to the permanent magnet motor.

Explains Weeds, “Copper has always been recognized as the preferred material for conducting electricity, which is why it’s used universally in motor windings”. Copper induction motors have comparable torque and efficiency, along with a rugged, durable design. Advantages to the copper induction motor include copper rotors don’t have a drag loss when the motor turns on and they don’t lose their efficiency during high speed or low torque conditions. This makes them well suited for hybrid and plug-in hybrid vehicles.

Copper rotors provide an economic advantage over aluminum rotors. Although the raw material cost for aluminum may be less than copper, the motor with a cast copper rotor can be up to 25% smaller than an equivalent motor with an aluminum rotor. The superior heat conduction of copper also contributes to cost savings.

The use of die-cast copper rotors (an improved technology that takes into account copper’s much higher melting temperature than aluminum, for example) provides an efficient, high production process. Reasons Bob Weed, “With these advantages, more motor manufacturers are now evaluating induction motors with cast copper rotors for electric vehicles”. Also worth considering are some facts about copper as far as automobiles are concerned. The average car produced in North America has 50-55 pounds of copper in it. In an electric car the amount of copper used, triples to 150-180 pounds. More than two-thirds of the copper will be found in car’s wiring harness and electrical components.

According to the European Copper Association, Copper finds application in not only a vehicle’s electrical wiring harness and electrical components, it is also increasingly finding its way into other mechanical and electromechincal components. What works in favour of Copper is its property to offer the highest conductivity of any metal that can be practically used for conveying electricity. Copper is also highly recyclable. General Motors has shown interest the powerful permanent magnet design for the pending 2013 Spark EV. The advantages offered by electrification will be incorporated into a number of vehicles, according to GM sources, and the Spark EV with a motor built in USA is expected to showcase how potent EV power can be by offering 37-percent more horsepower than the internal-combustion version.

The Korean-made, gasoline-powered 2013 Spark will make use of a tiny 1.2-litre four-cylinder with 83 horsepower and approximately 80 pound-feet of torque. In contrast, the electric car will kick out 85 kilowatts (114 horsepower) and instant torque – GM is not divulging the torque figure, but it is sure to be sufficient. The car will employ A123 batteries.