Electric automobile overspeed protection control method and system and electric automobile

Abstract

The invention provides an electric automobile overspeed protection control method, an electric automobile overspeed protection control system and an electric automobile. The electric automobile overspeed protection control method comprises the steps as follows: Step 1), monitoring the current rotational speed N and the current vehicle speed V of a motor; Step 2), judging whether the current rotational speed N is greater than a preset protective rotational speed N1, if so, executing the Step 1), and otherwise, executing Step 3); and Step 3), obtaining overspeed protection torsional moment Tq_regens according to the current rotational speed N and the current vehicle speed V of the motor, and controlling the motor to decrease the speed based on the overspeed protection torsional moment Tq_regens. The electric automobile overspeed protection control method supplies reverse torsional moment to the motor for decreasing the rotational speed of the motor when the current rotational speed of the motor is over high, so that the problem that when the electric automobile travels on a downs slope, particularly travels on a long down slope or travels on a down slope via stepping an accelerator pedal, the rotational speed of the motor is increased along with the increasing of the vehicle speed due to the action of gravity, is solved, and further, the normal traveling of the electric automobile is ensured.

Description

Technical field [0001] The invention belongs to the field of electric vehicle control, and in particular relates to an electric vehicle overspeed protection control method, system and electric vehicle. Background technique [0002] The energy crisis and the worsening of the environment have caused new energy vehicles with drive motors to replace traditional internal combustion engine vehicles as one of the important means to promote social development. Electric vehicles, as a model of energy conservation and environmental protection in new energy vehicles, have become major The focus of research and development for automobile manufacturers. Generally speaking, electric vehicles are divided into pure electric vehicles (BEV), hybrid electric vehicles (HEV), and fuel cell vehicles (FCEV), all of which use a power battery pack as a power source, and the entire vehicle is driven by a drive motor. Since the drive motor in the existing electric vehicles has no resistance torque, in ele...

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Problems solved by technology

[0004] Although the protection method and protection device provided by the above-mentioned patent application can avoid to a certain extent the overspeed fault caused by the excessive speed of the vehicle, it still inevitably has the following problems in practical application: one, due to the existing technology It does not actively provide resistance to decelerate the vehicle, so that when the driver does not take the corresponding deceleration action during a long downhill or when the accelerator pedal is pressed down, the motor speed will still change with gravity due to the effect of gravity. Second, when the connection between the motor controller MCU and the motor is disconnected due to the excessive speed of the motor, the vehicle must be powered on and off again to restore the drivability of the vehicle; Third, when an overspeed fault occurs, the system will cut off the power connection of the vehicle without any alarm indication, which will easily cause the driver to panic and lead to traffic accidents

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