Motor torque control method and device and electric automobile

Abstract

The invention provides a motor torque control method and device and an electric automobile, and relates to the technical field of electric automobiles. The device obtains the current temperature and the current rotating speed of a motor and judges whether or not the motor is in the over-temperature condition according to the current temperature; when the motor is in the over-temperature condition,the output torque of the motor corresponding to the current rotating speed is determined according to the pre-calibrated isothermal characteristic curve; the isothermal characteristic curve represents the corresponding relation between the output torque and the rotating speed in the over-temperature condition. Accordingly, when the motor is in the over-temperature condition, control over the besttorque of the motor can be achieved according to the pre-calibrated isothermal characteristic curve, the capability of the motor is brought into play to the great extent, the driving dynamic propertyand safety of the electric automobile are improved, and the user's driving experience is better.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a motor torque control method and device and an electric vehicle. Background technique [0002] The cooling methods of the drive motor of pure electric drive vehicles usually include water cooling and air cooling. When the vehicle continues to run with a large load, the temperature of the drive motor will rise rapidly. When the alarm temperature of the drive motor is reached, the vehicle control Torque limit and speed reduction are usually done by the controller. At present, the strategy of torque limit and speed reduction of automobiles is basically to force the torque below the rated power, which will bring bad driving experience to the driver, for example, it will cause greater jitter. ; At the same time, the simple and crude torque limiting strategy will also greatly sacrifice the power performance of the vehicle. [0003] Therefore, how to solve the problem of poo...

AI Technical Summary

Problems solved by technology

[0002] The cooling methods of the drive motor of pure electric drive vehicles usually include water cooling and air cooling. When the vehicle continues to run with a large load, the temperature of the drive motor will rise rapidly. When the alarm temperature of the drive motor is reached, the vehicle control Torque limit and speed reduction are usually done by the controller. At present, the strategy of torque limit and speed reduction of automobiles is basically to force the torque below the rated power, which will bring bad driving experience to the driver, for example, it will cause greater jitter. ; At the same time, the simple and crude torque limiting strategy will also greatly sacrifice the power performance of the vehicle

[0003] Therefore, how to solve the problem that when the drive motor is overheated, the poor driving experience caused by the vehicle control to roughly reduce the torque and greatly sacrifice the power performance of the vehicle has always been the focus of attention of those skilled in the art.

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