Control system and control method of hybrid electric vehicle

Abstract

A control system and a control method for a hybrid electric vehicle. The control system comprises a transmission apparatus (10), an engine power subsystem (20), a motor power subsystem (30), and a controller (40). The controller (40) controls the engine power subsystem (20) and the motor power subsystem (30) to control a hybrid electric vehicle to enter a hybrid power operation mode. After the controller (40) receives a switching instruction for switching into a pure electric power operation mode, if it is determined that an SOC of a power battery is greater than or equal to a second electric quantity threshold or a speed of the hybrid electric vehicle is lower than or equal to a first speed threshold, the controller (40) controls the hybrid electric vehicle to switch from a hybrid power operation mode to the pure electric power operation mode. The control system uses a parallel mode, and accordingly, it is easy to match power and the conversion efficiency is high; in addition, an engine is always in an operating state, the power performance of the hybrid electric vehicle is improved, and the degree of frequently starting and stopping the engine is reduced.

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] 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 tr...

AI Technical Summary

Problems solved by technology

However, the design concept of traditional hybrid electric vehicles is to reduce fuel consumption through motor-assisted regulation of the engine instead of completely eliminating fuel consumption. Therefore, it often does not have a manual EV (pure electric) mode switching function. 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 electric vehicles do not adopt a plug-in structure due to the small battery capacity. 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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