Battery state of charge estimation method and battery state of health estimation method

Abstract

The invention belongs to the field of battery management and provides a battery stat of charge estimation method and a battery state of health estimation method. With the battery state of charge estimation method and the battery state of health estimation method of the invention adopted, an open-circuit method, an ampere-hour method and a Kalman method can be used in a combined manner through objective and accurate judgment according to the actual physical state of a battery, so that the strengths of each of the methods can be drawn, and therefore, estimation accuracy and reliability can be improved. The state of charge estimation method comprises the following steps that: the working state, stable state, working state conversion mode and working characteristic region of a battery are periodically detected; an SOCocv is obtained through the open-circuit method according to the working state and stable state of the battery; an SOCqc is obtained through the ampere-hour method according to the working state, stable state and working characteristic region of the battery; an SOCklm is obtained through the Kalman method according to the working state and stable state of the battery; and weighted calculation is performed on the SOCocv, SOCqc, and SOCklm, so that a final SOC is obtained. With the battery state of charge estimation method and the battery state of health estimation method adopted, the problems of low precision and low reliability of an existing method which are caused by the failure of the existing method to perform collaborative estimation according to the current and past actual states of a battery can be solved.

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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