Method for estimating battery state of charge and method for estimating battery state of health

Abstract

The invention relates to the field of battery management, and provides a method for estimating the state of charge of a battery and a method for estimating a state of health of a battery, which can objectively and accurately judge how to choose a combination of the open circuit method, the Ampere-Time method and the Kalman method based on the actual physical state of the battery. Estimation accuracy and reliability. The state of charge estimation method includes periodic detection of the battery's working state, stable state, working state transition mode and working characteristic area; according to the battery's working state and stable state, the SOC is obtained by using the open circuit method ocv ;According to the battery working state, stable state and working characteristic area, the SOC is obtained by using the ampere-hour method qc ; According to the working state and steady state of the battery, the SOC is obtained by the Kalman method klm ; to SOC ocv 、SOC qc and SOC klm Do weighted calculations to obtain the final SOC. It solves the problem of low accuracy and reliability caused by the failure of existing methods to perform collaborative estimation based on the current and past actual states of the battery.

Description

technical field [0001] The invention relates to the technical field of battery management systems, in particular to a method for estimating a state of charge of a battery and a method for estimating a state of health of a battery. Background technique [0002] The Battery Management System (Battery Management System) is a system that manages rechargeable batteries. It usually has the functions of measuring battery voltage, current, temperature, etc., and is used to monitor the working status of the battery, ensure the safe operation of the battery, and prevent the battery from over-discharging and over-charging. Abnormal conditions such as charging and over temperature appear. [0003] One of the core functions of the battery management system is to estimate the state of charge (SOC) of the battery. Due to the nonlinear characteristics of the battery changing with the ambient temperature, it is a complex task to accurately estimate the state of charge of the battery. At pre...

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Problems solved by technology

[0009] For this reason, the technical problem to be solved by the present invention is that the battery state of charge estimation method and the battery health state estimation method of the prior art cannot judge whether to use and how to select and combine open circuit voltage method and ampere-hour integral according to the actual state of the current battery. method and Kalman filter method to estimate the battery state of charge and state of health, resulting in poor estimation accuracy, and provide a method that can accurately judge whether to use and how to use the open circuit voltage method, ampere-hour integral method and Kalman filter method based on the actual state of the current battery. Battery state of charge estimation method and battery health state estimation method based on filtering method

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