Online Estimation Method of Parameters of Simplified Impedance Spectroscopy Model of Secondary Battery Based on Fractional Joint Kalman Filter

Abstract

The invention discloses an on-line secondary battery simplified impedance spectroscopy model parameter estimating method based on fractional order united Kalman filtering, relates to an on-line estimation method of battery parameters, and aims to improve the accuracy, the estimation speed and the working condition adaptability of secondary battery parameter estimation. The method is based on a simplified battery impedance spectroscopy equivalent circuit model, a state equation and an observation equation required by an algorithm are established, the diffusion polarization end voltage (UW), the open-circuit voltage (OCVe), the internal ohm resistance (Ro) and the diffusion parameter (XW) of a battery are taken as the estimators by using a fractional order united Kalman filter, the end voltage (UL), the load current (IL) and the sampling time interval Ts being 1s which are measured in real time are taken as known amount, noise covariance is excited and measured according to the sensor precision selection process, and the estimation values of the open-circuit voltage (OCVe), the internal ohm resistance (Ro) and the diffusion parameter (XW) of a battery model are obtained. The on-line secondary battery simplified impedance spectroscopy model parameter estimating method is applicable to on-line estimation of secondary battery parameters.

Description

Technical field [0001] The invention belongs to the technical field of secondary battery testing and secondary battery energy storage system monitoring, especially the technical field of electric vehicle energy storage system monitoring. Background technique [0002] "An Online Method for Estimating the Internal Resistance of a Secondary Battery" with the publication number CN102680795 discloses a real-time online measurement method for the internal resistance of a secondary battery. It uses the internal resistance of the battery as an indicator for the estimation of the secondary battery, but this method only The performance and state of the secondary battery can be estimated on one index. Due to the limitations of the battery model, the estimation accuracy, accuracy, parameter stability, and working condition adaptability are limited, and the physical meaning of the battery model parameters is not clear enough. [0003] The traditional battery electrochemical impedance spectrosco...

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Problems solved by technology

[0002] Publication No. CN102680795 "On-line Estimation Method for Internal Resistance of Secondary Batteries" discloses a real-time online measurement method for internal resistance of secondary batteries. The performance and state of the secondary battery can be estimated on one indicator. Due to the limitations of the battery model itself, the estimation accuracy, accuracy, parameter stability, and working condition adaptability are limited, and the physical meaning of the battery model parameters is not clear enough.

[0003] The traditional battery electrochemical impedance spectroscopy test method needs to be carried out in a laboratory environment, requiring expensive experimental equipment and long test time

This method is difficult to apply to battery impedance spectrum online testing, battery state of health online estimation (SOH estimation), battery peak power state online prediction (SOP prediction) and other methods

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