Equalization structure for vehicle-mounted composite power supply system and equilibrium method of equalization structure

Abstract

The invention belongs to the field of new energy vehicles and battery management systems, and particularly relates to an equalization structure for a vehicle-mounted composite power supply system andan equalization method of the equalization structure. The equalization structure comprises a power lithium battery module, a super capacitor module, a bidirectional high-low-voltage DC / DC converter, alithium battery switch matrix, a super capacitor switch matrix and an equalization controller. Disequilibrium of energy consumption of a power battery is achieved by means of the composite power supply system, so that the running effect of a power system is improved. A battery equalization control system collects working condition parameters of the composite power supply system in real time and makes a decision equalization scheme, a lithium battery and the super capacitor switch matrix control the starting and shutting of equalization, and the energy in the power battery is transferred intoa super capacitor through the high-low-voltage DC / DC converter. The balance control system realizes the dynamic and static balance of the power battery, improves the performance and efficiency of thepower battery, prolongs the service life of the power battery, improves the problem of thermal management in a equalization circuit, improves the follow-up routine of an electric vehicle and realizesthe real-time correction of an SOC value of the power battery.

Description

technical field [0001] The invention belongs to the field of new energy vehicles and battery management systems, and in particular relates to an equalization structure and an equalization method of a vehicle-mounted composite power supply system. Background technique [0002] In the field of electric vehicles, the difference of the single cells in the power battery seriously affects the battery life and the driving range of the whole vehicle; due to the inconsistency between the individual cells in the battery pack, after continuous charge and discharge cycles, each Serious imbalances in the state of charge of the battery can cause permanent damage to the battery. [0003] The existing mainstream electric vehicle battery equalization management adopts passive equalization technology. In the battery pack, each single battery is connected in parallel with a balancing resistor to perform discharge shunting, so as to realize the energy balance of the single cells. In a battery ...

AI Technical Summary

Problems solved by technology

In a battery pack, a single cell B i When the difference between the voltage and the average voltage of the single battery reaches a certain threshold, the balance resistor will connect the single battery B i Part of the electricity is consumed in the form of heat energy, and its voltage value is reduced to the average level; the passive equalization structure is simple and low in cost, and has little impact on battery life, but due to the use of resistors for energy consumption, heat will be generated, thereby reducing the energy efficiency of the system; Active equalization is to transfer a battery with a slightly higher energy to a battery with a lower energy through the control circuit to achieve the effect of active distribution; active equalization improves the overall operating effect of electric vehicles, but the equalization structure is relatively complicated, and a large number of DC-DC The design of the converter, complex circuit structure and switch matrix increases the cost

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