Power system of all-wheel-drive hybrid power automobile and control method

Abstract

The invention discloses a power system of an all-wheel-drive hybrid power automobile and a control method. The power system comprises an engine, a first motor, a first inverter, a front-axle planet gear reducer, a second motor, a second inverter, a rear-axle reducer and a battery; the power system only comprises two motors and a set of simple planet gear mechanism and is relatively lower in cost, under the pure electric mode, the free selection of front-drive, rear-drive and all-wheel-drive can be achieved, the first motor further has two selectable gears, the opportunity of working at optimum efficiency is improved, and the pure electric economy is improved. Under the engine mode, starting and low-speed driving of the automobile can be achieved through the electronic stepless variable speed function, and the economy of low-speed driving of the automobile is improved. The engine has three selectable fixed gears which are used for direct driving in medium-high speed cruising, high-efficiency characteristics of the engine in high-load are used, the damage of electrical paths due to the electronic stepless variable speed is avoided, and the transmission efficiency is improved.

Description

technical field [0001] The invention relates to a power system of a hybrid electric vehicle, in particular to a power system and a control method of a four-wheel drive hybrid electric vehicle, and belongs to the technical field of electric vehicles. Background technique [0002] Four-wheel drive vehicles are widely used in off-road vehicles and high-performance vehicles due to their good road surface adhesion utilization. The traditional scheme of realizing the four-wheel drive function with a transfer case leads to poor economy of the vehicle due to the additional loss of the transfer case. To improve economy, four-wheel-drive hybrid vehicles use an engine and an electric motor to drive the front and rear axles, respectively. [0003] Patent CN102381177B discloses a hybrid four-wheel drive solution. When the engine is driving, the front axle generator must be used to generate power, and a part of the engine power is used for charging or powering the rear wheel motor. The e...

AI Technical Summary

Problems solved by technology

This solution uses a simple hybrid special transmission, the transmission cost is low, but compared with the system described in patent CN102381177B, there is one more motor, and because the engine cannot be directly driven at low speed, the engine needs to be driven by the generator when accelerating with high power. Power output, so the power of the generator is relatively large, and the total power requirements of the front axle drive motor and the rear axle drive motor are also large, the number of motors is large and the power requirement is large, so the cost is relatively high

[0006] To sum up, the main problems of the current hybrid front and rear axle drive schemes are high cost, poor transmission efficiency in some working conditions and inability to realize the four-wheel drive function in some working conditions.

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