Efficient composite energy storage system for vehicles

Abstract

The invention relates to an efficient composite energy storage system for vehicles, which comprises a super capacitor, a super capacitor management system, a power battery, a power battery management system, a one-way DC / DC converter, a power diode, a power dissipation device, a power switch and an energy storage system controller, wherein the super capacitor management system is used for controlling operation of the super capacitor, and the power battery management system is used for controlling operation of the power battery. The one-way DC / DC converter is in parallel connection with the power diode, an anode of the power diode is connected with an output end of the one-way DC / DC converter, a cathode of the power diode is connected with an input end of the one-way DC / DC converter, the anode of the power diode is further connected with an anode of the power battery, and the cathode of the power diode is further connected with an anode of the super capacitor. A cathode of the power battery, a cathode of the super capacitor and the one-way DC / DC converter are in common ground, and the power switch and the power dissipation device which are in serial connection are further connected between the anode and the cathode of the super capacitor. The power battery management system, the super capacitor management system, the power switch and the one-way DC / DC converter are coordinately controlled by the energy storage system controller. The efficient composite energy storage system is widely applicable to energy storage systems of new energy vehicles.

Description

technical field [0001] The invention relates to a new energy vehicle energy storage system, in particular to a high-efficiency composite energy storage system for vehicles based on supercapacitors and power batteries. Background technique [0002] With the increasingly severe energy crisis and global warming, energy conservation and emission reduction has become an urgent task for the global automotive industry, and new energy vehicles have therefore developed rapidly. Hybrid vehicles and pure electric vehicles are the most promising new energy vehicles. Two categories of development prospects. The power system of a hybrid vehicle is mainly composed of a power unit and an energy storage system. The function of the power unit is to convert the chemical energy of the vehicle fuel into mechanical energy and finally into electrical energy (diesel engine or gasoline engine), or directly into electrical energy (fuel cell engine); the role of the energy storage system is to provid...

AI Technical Summary

Problems solved by technology

This structure avoids the loss caused by the energy entering and exiting the bidirectional DC / DC converter, but its disadvantage is that the capacity of the supercapacitor cannot be fully utilized: because the change of the terminal voltage of the power battery with the SOC is a hard characteristic (that is, the SOC varies greatly, However, the terminal voltage does not change much), and the change of the terminal voltage of the supercapacitor with the SOC is a soft characteristic (that is, when the SOC changes, the terminal voltage also has a large change), so when the system is working, the voltage of the DC bus The power battery is always maintained within a very narrow range of change, resulting in the terminal voltage of the super capacitor and the corresponding SOC also changing within a very narrow range, which cannot be fully charged and discharged, which greatly limits the advantages of the super capacitor

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