Nissan Motor Company Limited

Jatco Corporation

Naoharu Ueda

Manabu Miura

Kenji Yoneda

An electric vehicle motor control device controls the transmission of power from an electric motor to driving wheels via an automatic transmission. The electric vehicle motor control device includes a vehicle speed detecting device that detects a vehicle speed of the electric vehicle and a controller. The controller includes a required driving power calculating section that calculates a required driving power of the electric vehicle, and a target motor rotational speed calculating section that calculates a target motor rotational speed. The target motor rotational speed is calculated so that an efficiency of a product of a power consumption rate of the electric motor and a transmission efficiency of the automatic transmission will become a prescribed target efficiency, based on the vehicle speed and the required driving power. The controller controls the electric motor based on the target motor rotational speed.

Motor control device for electric vehicle

To determine whether an exhaust gas purification catalyst () of an engine () has deteriorated, first deterioration of the catalyst () is determined on the basis of an excess air ratio difference, which is a value expressing a difference in the oxygen concentration on the upstream side and downstream side of the catalyst (). When the catalyst () is determined to have deteriorated on the basis of the excess air ratio difference, the air-fuel ratio of the engine () is feedback-controlled to a stoichiometric air-fuel ratio, and deterioration of the catalyst () is determined again on the basis of a value expressing a difference in the air-fuel ratio variation on the upstream side and downstream side of the catalyst () at that time.

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Yokohama, Japan

Naoharu Ueda