Method and device for controlling engine start of a hybrid electric vehicle

Abstract

The present invention discloses a hybrid electric vehicle engine start control method and control device, wherein the control method includes: step S1, after the hybrid electric vehicle is powered on, obtain the allowable discharge power of the power battery, the allowable charging power of the power battery and the actual consumption of the power battery power; step S2, when starting the engine, judge whether the difference between the allowable discharge power of the power battery and the actual power consumption of the power battery is less than the first threshold, or whether the allowable charging power of the power battery is less than the second threshold; step S3, if the power battery allows If the difference between the discharge power and the actual power consumption of the traction battery is less than the first threshold, or the allowable charging power of the traction battery is less than the second threshold, then the generator and the engine perform closed-loop speed control to start the engine in stages. The invention can effectively reduce the dragging power of the generator in the starting process, improve the smoothness of driving and starting, and avoid the engine from being dragged continuously during the starting process.

Description

technical field [0001] The invention relates to the technical field of new energy vehicles, in particular to a method and device for controlling engine starting of a hybrid electric vehicle. Background technique [0002] As fuel consumption and emission standards become more and more stringent, reducing fuel consumption and emissions has become the research and development focus of various automakers, and plug-in hybrid vehicles have become an important direction at present. Compared with traditional vehicles, the engine of hybrid electric vehicles starts frequently, which has a greater impact on emissions, and the start of the driving process also has a greater impact on ride comfort. Therefore, how to control engine starting has become one of the key technologies in the development of new energy plug-in hybrid electric vehicles. [0003] At present, the mainstream method for engine starting of plug-in hybrid electric vehicles is: the generator drives the engine to the tar...

AI Technical Summary

Problems solved by technology

This method has a higher drag target speed and requires a larger starting drag power, and the engine may not be able to start in an extremely low temperature environment, and starting during driving will have an impact on ride comfort

The generator speed closed-loop control is adopted in the whole process of starting, and there will be a certain charging power for the battery, and the low-temperature environment pulse charging current may cause the battery to report a fault

There may be generator drag torque during the whole process of starting, which will interfere with the engine's judgment of whether the starting is successful

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