Control apparatus for electric vehicle

U.S. Patent Number: 5731669

Abstract: A control apparatus for an electric vehicle includes a device for detecting a degree of depression of an accelerator pedal in the electric vehicle, and for outputting an accelerator depression degree signal representing the detected degree of depression of the accelerator pedal. A polyphase ac motor is operative for driving the electric vehicle. A rotational speed of the polyphase ac motor is detected, and a motor rotational speed signal is generated which represents the detected rotational speed of the polyphase ac motor. A battery in the vehicle generates dc power. An inverter changes the dc power into ac power through pulse width modulation responsive to a PWM modulation signal, and outputs the ac power to the polyphase ac motor to drive the latter. A steady torque command value is calculated on the basis of the motor rotational speed signal and the accelerator depression degree signal. A transient torque command value is calculated on the basis of a rate of a variation in the accelerator depression degree signal. A torque command value calculating device is operative for calculating a command value of a torque generated by the polyphase ac motor on the basis of the steady torque command value and the transient torque command value. A motor control device is operative for generating the PWM modulation signal in response to the torque command value calculated by the torque command value calculating device, and for outputting the PWM modulation signal to the inverter to control the polyphase ac motor.

Inventors: Shimizu; Takumi (Kariya, JP), Egami; Tsuneyuki (Gamagoori, JP)

Assignee: Nippondenso Co., Ltd. (Kariya, JP)

Application Number: 08/710,214

Issued: 1998-03-24

Expired: 2006-03-24

Classes: 318/139 ; 318/432; 318/587; 318/719; 318/800

Field of search: 318/138,139,245,254,560-696,800-832 364/424.06,424.02,424.01 477/20,15 74/866 361/28-32 363/40,39

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