Electric vehicle variable speed driving system and automatic variable speed control method

Abstract

The invention discloses an electromobile variable speed driving system and an automatic variable speed control method. The electromobile variable speed driving system comprises a driving motor, a motor controller, a gear shifting controller and a multi-gear transmission, wherein a main shaft of the multi-gear transmission is connected with a rotating shaft of the driving motor through a gear transmission mechanism; one end of a variable speed hub of the multi-gear transmission is electrically connected with the gear shifting controller through a gear contact switch, and the other end of the variable speed hub is connected with a shaft of a gear shifting motor; and the gear shifting controller is electrically connected with the gear shifting motor, a rotating speed sensor of the driving motor, the gear contact switch and the motor controller. The automatic variable speed control for the electromobile variable speed driving system is realized through presetting the lower limit eta min of the working efficiency of the driving motor in a program of the gear shifting controller, comparing the calculated real-time operational efficiency eta c of the driving motor with the set lowest working efficiency eta min of the driving motor, and then controlling the gear shifting motor to drive the variable speed hub to drive the transmission to finish gear-up and gear-down actions.

Description

technical field [0001] The invention relates to the field of variable-speed driving of electric vehicles, in particular to a variable-speed driving system of an electric vehicle and an automatic variable-speed control method. Background technique [0002] Electric vehicles are a safe, economical and clean green means of transportation. As people pay more attention to environmental and energy issues, electric vehicles, as a green and environment-friendly means of transportation, have their unique advantages and competitiveness, and are getting more and more attention. domestic and international attention. my country has also included its development in the focus of the development of the automobile industry. The electric vehicle requires the drive motor to have a small current when it is running stably, and it requires a large starting torque when it is running at full load. In terms of battery capacity, the specific power, specific torque and efficiency of the driving moto...

AI Technical Summary

Problems solved by technology

The drive motor and other power adjustable speeds used in this electric vehicle drive method require more power reserves for the actual operating conditions, and the waste of power reserves is large.

Its own disadvantages are: 1. When going uphill and when accelerating with heavy load, the current is large, the power consumption is large, and the power is not enough to be applicable when going uphill, and when going uphill and when accelerating with heavy load, it is easy to cause a sharp current Larger, the efficiency of the driving motor is low, and it is easy to burn the controller and the motor, and at the same time, the high current discharge directly affects the life of the battery; 2. The overall efficiency of driving under various road conditions is low, and the cruising range is short; 3. Relying on regulation to drive The current of the motor realizes the speed regulation, the acceleration performance is poor, and the climbing energy is weak

[0005] The other type is composed of a drive motor plus a clutch plus a two-speed transmission mechanism. The clutch structure is provided in the whole system, the transmission loss is large, the system efficiency is low, and the structure is complicated. The clutch parts need to be replaced regularly, and the use cost is high; and due to the two The speed ratio between the two gears of the gear transmission mechanism is quite different, the impact during the gear shifting process is too large, and the ride comfort is reduced; and manual operation is required to control the clutch to achieve gear shifting, and automatic gear shifting cannot be realized

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