Control system and control method of hybrid electrical vehicle (HEV)

Abstract

A hybrid electrical vehicle (HEV) control system and method, the control system comprising a transmission device (10), an engine power subsystem (20), a motor power subsystem (30) and a controller (40); the controller (40) enables the HEV to enter a hybrid power economical mode by controlling the engine power subsystem (20) and the motor power subsystem (30); if a detected current gradient signal is below or equal to a gradient lower threshold, and the SOC of a power battery (7) is below or equal to a first electric quantity threshold, or if the current gradient signal is below or equal to the gradient lower threshold, and the maximum allowable discharge power of the power battery (7) is below or equal to a first power threshold, then the controller (40) controls the HEV to operate in a low-power mode. In a parallel connection, the control system enables easy power matching, and provides high conversion efficiency and a high starting point of an engine, effectively reducing fuel consumption and emissions, reducing frequent engine start and stop, thus extending the service life of a starter, reducing noise during vehicle travel, and improving driving comfort.

Description

Technical field [0001] The present invention relates to the field of automobile technology, in particular to a control system of a hybrid electric vehicle and a control method of a hybrid electric vehicle. Background technique [0002] Hybrid Electrical Vehicle (Hybrid Electrical Vehicle, referred to as HEV) refers to a vehicle equipped with two power sources, namely, a heat 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 in hybrid vehicles, the power system can be flexibly adjusted according to the actual operating conditions of the vehicle, while the engine is kept working in the area with the best overall performance, thereby reducing fuel consumption and emissions. [0003] Some of the existing hybrid vehicles use a series-parallel hybrid system, which is characterized in that the internal combustion engine system and the motor drive system each have a set of...

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 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. ECVT (Electronic Continuously Variable Transmission, Electronically controlled continuously variable automatic transmission) is difficult to match and the cost is high

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