Electric vehicle and motor overspeed protection method and device of same

Abstract

The invention provides an electric vehicle and a motor overspeed protection method and device of the same. The motor overspeed protection method is used for protecting a power tube of a motor controller which is connected with a motor, and comprises the following steps of: obtaining the current rotating speed V of the motor; judging whether the current rotating speed V is larger than a first set rotating speed Vset1, and sending a protective operation signal if the current rotating speed V is larger than the first set rotating speed Vset1; and disconnecting the motor and the motor controller according to the protective operation signal. When the motor overspeed protection method is adopted, the power tube of the motor controller can be prevented from being penetrated by counter potential produced by the motor due to too fast rotating speed of the motor, so that the safety of the motor controller as well as the tolerance of the motor can be improved, and therefore the normal operation of the electric vehicle is ensured.

Description

technical field [0001] The invention belongs to the field of automobiles, and in particular relates to a motor overspeed protection method for an electric vehicle, a protection device and the electric vehicle. Background technique [0002] Due to the depletion of oil resources and the increasingly serious environmental pollution, new energy vehicles have become the focus of the development of the automobile industry in various countries. For example, as a new energy vehicle that is both energy-saving and environmentally friendly, electric vehicles have become the focus of new energy vehicle development. However, the motor as the power system of an electric vehicle does not have its own resistance like a traditional engine. Therefore, when the whole vehicle is going downhill, especially when going down a long slope, the speed of the motor can easily reach its set maximum speed with the increase of the speed of the whole vehicle. At this time, if the driver does not take bra...

AI Technical Summary

Problems solved by technology

At this time, if the driver does not take braking action or any other deceleration measures, the speed of the motor will easily exceed its set maximum speed, and the motor’s back EMF is proportional to the motor’s speed, and the increase of the motor’s speed will inevitably lead to the back EMF If the voltage limit of the power tube of the motor controller is exceeded, the power tube will be damaged due to voltage breakdown, and the electric vehicle will not be able to drive normally

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