Electric vehicle independent four-wheel hub electric drive system, voltage and power design method and control method of each drive unit

Abstract

The invention discloses an independent four-hub electrically driven system of an electric automobile, a voltage-power design method of each unit and a control method of the independent four-hub electrically driven system and relates to technical field of short-distance full-electrically-driven passenger vehicles. The independent four-hub electrically driven system comprises four hub motors, four driving systems, a vehicle control unit and a meter-display and driver-input system, wherein the four driving systems are respectively connected with the four hub motors and are used for driving the hub motors. The independent four-hub electrically driven system is characterized by being provided with four power battery packs and management systems, wherein the four power battery packs and the management systems are respectively connected with the four driving systems and are used for supplying direct current to the four driving systems. The invention further discloses control methods of the four driving systems under different working states. The independent four-hub electrically driven system has the advantages that the total numbers of unit cells of the four power battery packs is small, a unit cell pack is long in life, high in energy recovery efficiency and short in charging time, the modular and standard production of the electric automobile is easy to realize, the cost can be effectively lowered, and the reliability of the whole vehicle is improved.

Description

technical field [0001] The invention relates to the technical field of short-distance pure electric passenger vehicles, and in detail relates to an electric vehicle independent four-wheel-hub electric drive system structure and control method with a small number of battery units, a long service life, a fast charging speed, and high energy recovery efficiency. Background technique [0002] Short-distance pure electric passenger vehicles meet the lower limit of the "Technical Conditions for Pure Electric Passenger Vehicles" (GB / T 28382-2012), and are positioned to replace low-speed pure electric passenger vehicles currently on the market. According to the "Technical Conditions for Pure Electric Passenger Vehicles", the lower limit of the maximum speed of short-distance pure electric passenger vehicles is 80km / h. Combined with the use of short-distance pure electric passenger vehicles, they are mainly driven on urban and rural roads, regardless of the driving needs of expressway...

AI Technical Summary

Problems solved by technology

[0008] Although the independent four-wheel-hub electric drive system with the above structure solves the problem of four-wheel independent drive, but because a single battery pack is used to supply power to the four-wheel-hub electric drive system at the same time, there are the following problems in the power supply system: the number of battery cells in the battery pack is large , The service life is short, when the battery pack is charged externally, it can only be charged by one charger, and the charging time is long; when the braking energy is recovered, the four hub motor drive systems charge the battery pack at the same time, and the four hub motor drive systems It affects the DC bus voltage of the battery pack, and the charging current is affected by the voltage difference, causing the braking energy recovery process of the four in-wheel motor drive systems to affect each other, affecting the braking energy recovery efficiency

The power and voltage of each hub motor in the traditional four-wheel hub electric drive system are consistent, the overall structure design of the car is limited, and the vehicle structure is unreasonable; the power of each drive unit is constrained by other drive units, and the power design of each drive unit is single

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