A Peak Power Prediction Method Considering the Impact of Traction Battery Durability

Abstract

The present invention provides a peak power prediction method considering the influence of the durability of the power battery. Compared with the prior art, in addition to taking the maximum temperature value of the battery as a constraint, the battery temperature change rate constraint and aging constraint are also added. Since the change rate of the temperature rise of the battery can well reflect the health change of the battery when the battery is at any ambient temperature, the present invention can better reflect the change of the health state of the battery, reduce capacity loss, and improve durability. In addition, considering that the current rate will affect the capacity decline trajectory of the battery, the present invention derives the relationship between the current rate and the capacity decline constraint from the capacity loss model, and uses the capacity decline limit as a constraint to predict the peak current of continuous charge and discharge, and then Realizing the peak power prediction of continuous charging and discharging of batteries is of great significance to the durability of batteries.

Description

technical field [0001] The invention relates to the technical field of a power battery system, in particular to research on a peak power prediction method of a power battery. Background technique [0002] The peak power of electric vehicles directly affects the acceleration climbing performance and regenerative braking energy recovery capability. If the peak power is too low, the energy provided by the battery will not be able to meet the needs; if the peak power is too high, it will cause irreversible damage to the battery and shorten the service life of the battery. In view of the non-direct measurement of peak power, it is very necessary to accurately predict it. [0003] At present, in the process of predicting the peak power of power batteries, the state of charge (SOC), terminal voltage, temperature and the maximum current of the battery design are mostly used as constraints to predict the peak current, so as to realize peak power prediction. . But in fact, compared...

AI Technical Summary

Problems solved by technology

Excessive temperature rise means that side reactions inside the battery occur, resulting in a reduction in the number of available lithium ions and accelerating battery aging

In addition, excessive peak current will cause some lithium ions to accumulate on the surface of the active material before the positive and negative electrodes of the battery can combine with electrons, which also causes the consumption of available lithium ions, accelerates the aging speed of the battery, and affects its warranty mileage and warranty time

It can be seen that for the improvement of battery durability, in addition to considering the conventional SOC, terminal voltage, temperature and factory current limit constraints, the temperature rise rate and aging constraints are also an important factor to be considered in the peak power prediction. However, there is still a lack of research on this aspect in the prior art

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