Nissan Increases Drive Range of Leaf EV

Nov 21, 2012
Naoshige Shimizu, Nikkei Automotive Technology
The power module containing a motor, inverter, DC-DC converter, etc from the bottom
The power module containing a motor, inverter, DC-DC converter, etc from the bottom
[ If it clicks, the expanded picture will open ]
The battery pack
The battery pack
[ If it clicks, the expanded picture will open ]

Nissan Motor Co Ltd made improvements to its Leaf electric vehicle (EV) and increased the drive range of the EV from 200km to 228km per charge under the JC08 test mode.

This time, Nissan increased the efficiency of the EV's motor and reduced the weight of the auto body. While lowering the maximum torque of the motor from 280N·m to 254N·m, the company increased its efficiency. Though the company continued to use a permanent magnet three-phase synchronous motor, it changed the size of the stator's teeth and the number of turns in the coil.

The weight of the Leaf was reduced by about 80kg to 1,440kg by, for example, reducing the mass of its battery case. Nissan also reduced the number of the bolts used for the battery module, slimmed brackets and reduced the weight of the battery module's package.

Moreover, Nissan directly connected the motor with the inverter and eliminated the need for the bracket between them. The bracket was used to prevent the motor's vibration from being transmitted to the inverter and DC-DC converter, which are located on the motor, and increasing.

Nissan improved the rigidity of the lid of the box that stores the DC-DC converter so that it does not vibrate much. The company changed the shape of the lid from a planar shape to a curved shape and formed a honeycomb rib having regular hexagonal holes on the back of the lid.

Nissan reduced the size of the charger, moved it to the front side and integrated it with the DC-DC converter, etc. As a result, the capacity of the luggage room increased from 330 to 370L.

Furthermore, Nissan made an improvement to the coordinated regenerative brake that uses both a friction brake and a regenerative brake so that the regenerative brake is used when the vehicle speed is 3km/h or faster. In the former model of the Leaf, the regenerative brake is used when the vehicle speed is 7km/h or faster. This improvement also contributed to the extension of the drive range.