A method and system for predicting the available power of lithium batteries under multiple constraints

Abstract

The invention proposes a method and system for predicting the available power of a lithium battery under multiple constraints. The prediction method includes the following steps: establishing an equivalent circuit model of the lithium battery, and determining the state space expression of the lithium battery; The idea of ​​square error performs online recursive identification of the parameters of the equivalent circuit model; predicts the battery temperature according to the parameters of the equivalent circuit model; estimates the state of charge and energy state of the lithium battery according to the state space expression; according to the parameters of the equivalent circuit model And the predicted battery temperature to determine the limit charging power and limit discharging power under the multiple constraints of terminal voltage, current, state of charge, energy state and temperature. The invention proposes a SoP prediction method with multiple constraints in terms of voltage, current, SoC, SoE and temperature. Through the SoP prediction under the multiple constraints, the accuracy and reliability of the SoP prediction are improved, and the safety of automobiles is improved. Purpose.

Description

technical field [0001] The invention relates to the technical field of lithium battery state prediction, in particular to a method and system for predicting the available power of a lithium battery under multiple constraints. Background technique [0002] In order to grasp the ability of the on-board power battery system to meet the power requirements of vehicle overtaking, climbing, constant speed driving, and regenerative braking, it is necessary to predict the SoP of the battery in real time. The power capability of a battery is limited by multiple constraints, such as terminal voltage, current, state of charge, and state of energy. [0003] Most of the existing technologies only consider the limit of terminal voltage, and some methods will add the limit of SoC, but lack the explicit consideration of the predicted duration, so the predicted power is quite different from the actual, and the practicability is not strong. . [0004] For example, the most commonly used SoP ...

AI Technical Summary

Problems solved by technology

But the battery model it uses is very rough, with too few constraints (only voltage) and does not explicitly consider the time frame, so the PNGV-HPPC method usually gives overly optimistic results, causing the battery system to suffer from electrical abuse

There are also some commonly used improvement methods with too few constraints, such as not clearly considering the time range, ignoring the safe operating temperature, etc., which may lead to thermal runaway effect, permanent failure of the battery, and even the risk of fire.

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