Composite energy storage system based on stepless speed change type flywheel and power battery

Abstract

A composite energy storage system based on a stepless speed change type flywheel and a power battery is characterized in that the composite energy storage system can be controlled to operate in different working modes according to different automobile operation working conditions, and the requirements of an automobile for high power density, high energy density, high energy conversion efficiency and long service life of the energy storage system can be met at the same time. Under the starting condition of the vehicle, the discharge current of the power battery can be reduced and the service life of the power battery system can be prolonged by virtue of the high-power density advantage of the stepless speed change type flywheel; under medium-high driving demand power, the composite energy storage system works in a dual-energy supply mode, and by means of the advantage of high power density based on the stepless speed change type flywheel, the power demand of the whole vehicle can be met, large-current discharge of a power battery can be prevented, the service life of the power battery is prolonged, and the working efficiency of the system is improved; under low driving demand power,based on the fact that the stepless speed change type flywheel does not participate in whole vehicle driving, the whole vehicle controller controls the electric energy output by the power battery tobe converted into mechanical energy through the motor at the same time, and then part of the remaining mechanical energy obtained after whole vehicle driving is met is transmitted to the flywheel so as to control the stepless speed change type flywheel to operate in an efficient state; and under the emergency braking working condition, by means of the advantage of instantaneous high-power feedbackbased on the stepless speed change type flywheel, more braking energy can be fed back compared with a conventional single-power-battery energy storage system, the energy utilization efficiency of thewhole vehicle is improved, large-current charging of a power battery can be prevented, and the service life of the power battery is prolonged.

Description

technical field [0001] The invention relates to a composite energy storage system, in particular to a composite energy storage system based on a continuously variable flywheel and a power battery. Background technique [0002] In electric vehicles, the energy storage system has a large impact on the overall efficiency of the vehicle. Electric vehicles require the energy storage system to be able to recover and release a large amount of power in a short period of time, which requires the energy storage system to have a relatively high power density. In addition, because the vehicle energy storage system cannot be too heavy, the energy storage system should also be required to have a relatively high energy density. Power battery is a relatively common vehicle energy storage system, which includes different types of lead-acid batteries, nickel-metal hydride batteries, lithium polymer batteries, etc. Among them, the most promising application is lithium polymer batteries, which...

AI Technical Summary

Problems solved by technology

Since the continuously variable flywheel energy storage system has a great power density advantage, it is designed as a vehicle auxiliary energy system. With the advantage of the instantaneous high power output of the flywheel, on the one hand, it can effectively reduce the power under the driving conditions of sudden load changes. The instantaneous discharge current of the battery improves the working efficiency of the on-board energy system and solves the problem of low energy utilization efficiency and service life of the conventional single power battery energy storage system; More energy than the conventional single power battery energy storage system, prolonging the service life of the power battery energy storage system, and further improving the comprehensive utilization efficiency of vehicle energy

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