Hybrid electric vehicle engine starting control method and device

Abstract

The invention discloses a hybrid electric vehicle engine starting control method and device. The control method comprises the steps: S1, obtaining allowable discharge power of a power battery, allowable charge power of the power battery and actual consumption power of the power battery after a hybrid electric vehicle is powered on; S2, when the engine is started, judging whether a difference valuebetween the allowable discharge power of the power battery and the actual consumed power of the power battery is smaller than a first threshold value or whether the allowable charge power of the power battery is smaller than a second threshold value or not; and S3, if the difference value between the allowable discharge power of the power battery and the actual consumed power of the power batteryis smaller than the first threshold value or the allowable charge power of the power battery is smaller than the second threshold value, performing rotational speed closed-loop control by the generator and the engine respectively, and starting the engine in stages. In the invention, dragging power of the generator in a starting process can be effectively reduced, smoothness of driving starting can be improved, and the engine is prevented from being dragged all the time in a 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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