Control system and control method for hybrid electric vehicle

Abstract

The invention discloses a control system and a control method of a hybrid electric vehicle, wherein the control system includes: a transmission device; an engine power subsystem; a motor power subsystem; a controller, and the controller controls the engine power subsystem and the motor power subsystem To control the hybrid electric vehicle to enter the corresponding working mode, and after the controller receives the switching instruction to switch to the pure electric economic mode, if it is judged that the SOC of the power battery is greater than or equal to the second power threshold and the vehicle speed of the hybrid electric vehicle is less than or equal to the first When the speed threshold is reached, the hybrid electric vehicle is controlled to switch from the hybrid economic mode to the pure electric economic mode. The engine power subsystem and the motor power subsystem in the control system of the hybrid electric vehicle adopt a parallel connection mode, the power is easy to match, the conversion efficiency is high, the fuel consumption and emission are reduced, and the frequent start and stop of the engine is reduced, thereby improving the life of the starter. Reduce driving noise and increase driving comfort.

Description

technical field [0001] The invention relates to the technical field of automobiles, in particular to a control system of a hybrid electric vehicle and a control method of the hybrid electric vehicle. Background technique [0002] A hybrid electrical vehicle (HEV) refers to a vehicle that is equipped with two power sources at the same time, that is, a thermal power source (generated by a traditional gasoline engine or a diesel engine) and an electric power source (generated by a battery and a motor). By using electric motors on hybrid electric vehicles, the power system can be flexibly adjusted according to the actual operating conditions of the vehicle, while the engine keeps working in the area with the best overall performance, thereby reducing fuel consumption and emissions. [0003] Some of the existing hybrid vehicles use a hybrid hybrid system, which is characterized in that the internal combustion engine system and the motor drive system each have a set of mechanical ...

AI Technical Summary

Problems solved by technology

The design concept of traditional hybrid electric vehicles is to reduce fuel consumption by adjusting the engine with motor assistance instead of completely eliminating fuel consumption, so it often does not have a manual EV (pure electric) mode switching function, even if it does, it will lead to pure electric driving due to battery capacity limitations short mileage

[0005] At the same time, traditional hybrid electric vehicles do not use high-power, high-torque motors and engines for the purpose of reducing fuel consumption, which will result in weak vehicle power and greatly reduced driving pleasure.

For example, the acceleration time of some hybrid vehicles from 100 kilometers to 10 seconds exceeds 10 seconds, and the high-speed performance is also poor.

[0006] Furthermore, some hybrid electric vehicles adopt a parallel structure and its control method, and there is no strategy for the engine to be driven independently. Adjusting the engine speed through MG1 to achieve gear shifting; and in the case of heavy load acceleration, limited by the capacity of the battery, a part of the power of the engine must drive MG1 to generate electricity before it can work with the battery to provide electric power to the second motor MG2. Both of the above two points Reduced drive efficiency of the engine

Moreover, in the engine start-off strategy, the set required power and vehicle speed limits are too small, and the vehicle speed switching condition is set as a point instead of an interval, which will cause the engine to start prematurely and frequently

[0007] In addition, some existing hybrid vehicles do not adopt a plug-in structure due to the small battery capacity, and the battery power is converted from gasoline, which increases the cost of use. At the same time, the hybrid structure is relatively complicated. Controlled continuously variable automatic transmission) matching is difficult and costly

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