Dynamics battery-super capacitance mixed dynamic system for electric car

Abstract

The invention relates to a power battery-super capacitor hybrid power system for electric automobiles, belonging to the electric automobile technical field. The power battery-super capacitor hybrid power system for the electric automobiles comprises a power battery pack, a motor controller and a 24V storage battery, a boost DC / DC converter, a bi-directional DC / DC converter and a super capacitance group, wherein, the low voltage end of the boost DC / DC converter is connected with the output end of the power battery pack, the high voltage end of the boost DC / DC converter is connected with the motor controller; the super capacitance group and the high voltage end of the bi-directional DC / DC converter are directly hitched with the high voltage end of the boost DC / DC converter, and the low voltage end of the bi-directional DC / DC converter is connected with the 24V storage battery. The power battery of the power battery-super capacitor hybrid power system for the electric automobiles has smooth output current, small peak current, high discharge efficiency and long service life; when the battery pack SOC is lower, the hybrid system still ensures the normal power output capability; and the super capacitance can directly absorb the braking feedback energy and has high energy conversion efficiency.

Description

technical field [0001] The invention belongs to the technical field of electric vehicles, and in particular relates to a power battery-supercapacitor hybrid power system for electric vehicles. Background technique [0002] Electric vehicles have the characteristics of environmental protection, energy saving and high energy conversion efficiency, and have been paid more and more attention. The power battery pack is the core part of the electric vehicle. Improving the energy efficiency of the power battery pack during the discharge process, the utilization rate of the battery pack's energy storage, and prolonging the service life of the power battery pack are one of the key technologies for the development of the electric vehicle power system. [0003] Restricted by the working principle and manufacturing level of power batteries, the discharge efficiency of advanced power battery packs (such as nickel-metal hydride battery packs, lithium-ion battery packs, etc.) for electric ...

AI Technical Summary

Problems solved by technology

Due to the frequent acceleration of the vehicle under urban working conditions, the power battery pack is frequently discharged with high current, which reduces the energy efficiency and service life of the battery pack, thus affecting the energy efficiency and service life of the vehicle

[0004] On the other hand, when electric vehicles are running in urban areas, due to the characteristics of urban working conditions, the vehicles are frequently in the process of acceleration, deceleration and idling. In the state of high current discharge, however, in the process of vehicle deceleration and coasting, the output power of the power system is very small or even zero. At this time, the discharge current of the power battery pack is small or does not discharge

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