|Components of the emDRIVE MD system. Click to enlarge.|
Ioxus, Inc., a manufacturer of premium performance ultracapacitor technology (earlier post) is providing ultracapacitors to ElectroMotive Design LLC (EMD), an engineering services company and a manufacturer of hybrid electric conversion systems for Class 2 through 8 buses and trucks.
Ioxus’ ultracapacitors are used for energy storage in EMD’s emDRIVE systems, which come in a range of sizes. emDRIVE lite is available in two sizes to accommodate vans and buses with GVW’s ranging from 6,000 to 14,000 lbs. emDRIVE MD is available in two sizes to accommodate vans and buses with GVW’s ranging from 14,000 to 19,000 lbs. Each system utilizes similar core architecture and control components.
|Ioxus 3000F iCAP quick Specs|
|ESR, DC ≤(mΩ) [10ms]||0.26|
|ESR, AC 1kHz ≤(mΩ)||0.22|
|72hr Leakage ≤(mA)||5.0|
|Current, Peak [1s] (A)||2300|
|Continuous Current (A)||145|
|Resistance, Thermal (°C/W)||4|
The emDRIVE systems provide 20 to 60kW of electric power to a conventional drive train, and 20 to 60kW of stopping power when the brake pedal is applied. Regenerative braking charges the energy storage system for later use instead of being wasted as unrecovered heat.
In addition, EMD’s emDRIVE extends the life of brake pads anywhere from 50 to 100%. With increased fuel mileage and reduced maintenance requirements, EMD customers can see a payback in two to three years, according to the company.
Rated at 2.7V (2.85V surge), the new iCAP 3000F cell represents the lowest weight, lowest equivalent series resistance (ESR) and highest power density currently available in the market for energy storage cells, Ioxus says. The cells feature a cycle life of more than 1,000,000 cycles, rated to half rated voltage, 25 °C.
We use ultracapacitors as our system’s energy storage medium in order to capture regenerative braking energy to be used later to assist the vehicle’s acceleration. Because ultracapacitors are highly efficient at energy recapture and storage, they are best able to handle the high power bursts we needed for our hybrid conversion systems to deliver the highest fuel efficiency.—Joseph Ambrosio, General Manager of EMD