Method for determining parameters of an electrochemical energy store in a computer-aided manner

Patent metadata

Field	Value
Publication number	US-10877101-B2
Application number	US-201615775841-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Nov 17, 2015
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

Provided is a method for determining parameters of an electrochemical energy store in a computer-aided manner, wherein a plurality of temporally successive measurement data records having respective assigned measurement times and a predefined model of the energy store are processed. A particular measurement data record includes a measured voltage value of a terminal voltage of the energy store, a measured current value of a current flow in the form of a charging or discharging current of the energy store and a state of charge measured value of the state of charge of the energy store Equation parameters of at least one linear equation system are stipulated in the method, which equation system is based on the predefined model.

First claim

The invention claimed is:

1. A method for determining parameters of an electrochemical energy store in a computer-aided manner, wherein a multiplicity of chronologically successive measurement data records are processed, wherein a respective measurement data record of the chronologically successive measurement data records comprises the following measured values for an assigned measurement time: a measured voltage value of a terminal voltage of the energy store, a measured current value of a current flow in the form of a charging current or discharging current of the energy store, and a state of charge measured value of the state of charge of the energy store, wherein a predefined model of the energy store which describes the terminal voltage as a function of the state of charge and the current flow is processed, wherein the predefined model comprises the following indeterminate parameters:
a nominal open-circuit voltage which represents the open-circuit voltage of the energy store without a current flow at a predefined state of charge value, a voltage factor which is part of a term of the terminal voltage which is dependent on the state of charge, and an internal resistance of the energy store, which is part of a term of the terminal voltage which is dependent on the current flow, the method comprising:
stipulating equation parameters of at least one linear equation system which is based on the predefined model, by means of a plurality of first measurement data records in which the temperatures of the energy store are essentially the same, and/or by means of a plurality of second measurement data records which are pairs of measurement data records at successive measurement times with a current step in the current flows at the successive measurement times, and/or by means of a plurality of third measurement data records in which the current flows are essentially zero; and
determining the nominal open-circuit voltage and the voltage factor by solving the at least one linear equation system.

2. The method as claimed in claim 1 , wherein the predefined model of the energy store is based on the following equation:
U ( t )= U 0 nom +dU 0*( SOC ( t )− p )+ R ( T,SOC ( t ))* I ( t ),

where t is the time;
where U(t) is the terminal voltage;
where U 0 nom is the nominal open-circuit voltage;
where dU 0 is the voltage factor;
where p is the predefined state of charge value;
where SOC(t) is the state of charge,
where R(T,SOC(t)) is the internal resistance;
where T is the temperature; and
where I(t) is the current flow.

3. The method as claimed in claim 1 , wherein, in the predefined model, the internal resistance is described by a product of a first function and a second function, wherein the first function depends on the temperature of the energy store and the second function depends on the state of charge of the energy store, and wherein the first function is unknown and the second function is predefined.

4. The method as claimed in claim 2 , wherein the equation parameters of the linear equation system, or of one of the linear equation systems, are stipulated by means of the first measurement data records, and the linear equation system with the stipulated equation parameters is as follows:

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Assignees

• Siemens Ag

Inventors

• Severin Anja
• Wolfrum Philipp

Classifications

• G01R31/3842

  combining voltage and current measurements · CPC title

• G01R31/367 Primary

  Software therefor, e.g. for battery testing using modelling or look-up tables · CPC title

• G01R31/389

  Measuring internal impedance, internal conductance or related variables · CPC title