Methods for predicting SOC of vehicle-mounted power battery of electric automobile

Abstract

The invention discloses methods for predicting the SOC of a vehicle-mounted power battery of an electric automobile. The methods for predicting the SOC of the vehicle-mounted power battery of the electric automobile comprises the method for predicting the SOC in the charging mode, and the method for predicting the SOC in the discharging mode. The methods for predicting the SOC of the vehicle-mounted power battery of the electric automobile are based on an existing open-circuit voltage method and an existing ampere-hour integral method, an optimal battery model is obtained through curve fitting of the temperature, the voltage, the charging current and the discharging current of the battery, branch processing is conducted on the charging state and discharging state when an SOC value is estimated in real time, a corresponding SOC value is searched for in a model library by means of the immobilized battery model according to the temperature characteristic, the voltage characteristic and the current characteristic, of the battery, the SOC value is modified according to model errors, and the estimation accuracy is greatly improved.

Description

technical field [0001] The invention relates to the technical field of battery management, and more specifically, relates to a method for predicting the SOC of an electric vehicle vehicle-mounted power battery. Background technique [0002] The remaining capacity of the battery, also known as the state of charge (SOC) of the battery, is one of the important parameters of the battery state and provides a basis for the control strategy of the electric vehicle. Accurately estimate the remaining capacity of the current battery, ensure that the SOC is maintained within a reasonable range, prevent overcharge or overdischarge from causing damage to the battery, and provide a technical direction for us to use the battery reasonably, improve battery life, and reduce maintenance costs. How to accurately and reliably Obtaining the battery SOC value is the most basic and important task of the battery management system. [0003] Power batteries such as lead-acid power batteries, nickel-...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problems mentioned in the above-mentioned background technology, and to provide a method for predicting the SOC of the vehicle-mounted power battery of an electric vehicle. Curve fitting of voltage and charge and discharge current to obtain the best battery model, branch processing of the charge and discharge state in the real-time estimation of SOC value, using the cured battery model, the current temperature, voltage and current characteristics of the battery in the model library Search for the corresponding SOC value in , and correct the SOC value according to the model error, which greatly improves the estimation accuracy

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