Method for approximating algorithms for fast charging li-ion batteries based on electrochemical battery models

Patent metadata

Field	Value
Publication number	US-11243258-B2
Application number	US-201816188404-A
Country	US
Kind code	B2
Filing date	Nov 13, 2018
Priority date	Nov 13, 2018
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

A method, system, and non-transitory computer readable medium for determining a pseudo-optimal charging algorithm for a specific battery are disclosed. An electrochemical battery model is characterized based on the physical characteristics of a specific battery. An optimal charging profile is determined for the specific battery using the highly accurate electrochemical battery model. A pseudo-optimal charging profile is determined which closely approximates the optimal charging profile. However, the pseudo-optimal charging profile is comprised of simple building blocks which are easily and efficiently implemented in embedded applications having limited computational power/memory. An optimization process is used to determine optimal control parameters for the simple building blocks, trigger conditions and thresholds, and adaptation parameters for adapting the pseudo-optimal charging profile as the battery ages.

First claim

What is claimed is:

1. A method of approximating an optimal charging profile for a particular battery, the method comprising:
storing, in a memory, an electrochemical battery model that describes physical processes of batteries that lead to aging, the electrochemical battery model being parameterized based on physical characteristics of the particular battery;
determining, with a processor, a first charging profile that minimizes a charging time for the particular battery and minimizes a degradation of the particular battery using the electrochemical battery model; and
determining, with the processor, a first set of parameters that define a second charging profile that is formed by an ordered sequence of charging phases that approximates the first charging profile, each charging phase in the ordered sequence being characterized by (i) a respective first parameter in the first set of parameters indicating a respective control strategy that is to be used to control a charging current during the respective charging phase, (ii) a respective second parameter in the first set of parameters indicating a value of a control parameter of the respective control strategy, (iii) a respective third parameter in the first set of parameters indicating a respective trigger condition which, when satisfied, triggers the respective charging phase to end, and (iv) a respective fourth parameter in the first set of parameters indicating a value of a threshold parameter of the respective trigger condition, the determining of the first set of parameters that define the second charging profile further comprising:
calculating, for each charging phase in the ordered sequence, a value of the respective second parameter and an value of the respective fourth parameter that (i) minimizes a difference between the first charging profile and the second charging profile and (ii) minimizes a difference between a degradation of the particular battery caused by the first charging profile and a degradation of the particular battery caused by the second charging profile.

2. The method according to claim 1 , the determining of the first set of parameters that define the second charging profile further comprising:
receiving, via an input device, for each charging phase in the ordered sequence, a value of the respective third parameter.

3. The method according to claim 1 , the determining of the first set of parameters that define the second charging profile further comprising:
calculating, for each charging phase in the ordered sequence, a value of the respective third parameter that (i) minimizes a difference between the first charging profile and the second charging profile and (ii) minimizes a difference between a degradation of the particular battery caused by the first charging profile and a degradation of the particular battery caused by the second charging profile.

4. The method according to claim 1 , the determining of the first set of parameters that define the second charging profile further comprising:
receiving, via an input device, for each charging phase in the ordered sequence, a value of the respective first parameter.

5. The method according to claim 1 , the determining of the first set of parameters that define the second charging profile further comprising:
calculating, for each charging phase in the ordered sequence, a value of the respective first parameter that (i) minimizes a difference between the first charging profile and the second charging profile and (ii) minimizes a difference between a degradation of the particular battery caused by the first charging profile and a degradation of the particular battery caused by the second charging profile.

6. The method according to claim 1 , the determining of the first charging profile further comprising:
determining a plurality of first charging profiles that minimize the charging time for the particular battery and minimize the degradation of the particular battery using the electrochemical battery model, each first charging profile in the plurality of first charging profiles correspond to a different amount of degradation of the particular battery.

7. The method according to claim 6 , the determining of the set of parameters that define the second charging profile further comprising:
determining the first set of parameters that define the second charging profile that is formed by the ordered sequence of charging phases that approximates a charging profile in the plurality of first charging profiles corresponding to a least amount of degradation of the particular battery.

8. The method according to claim 7 , further comprising:
determining, with the processor, a second set of parameters used to adapt the second charging profile depending on an amount of degradation of the particular battery such that, when adapted using the second set of parameters based on a respective amount of degradation of the particular battery, the adapted second charging profile approximates a charging profile in the plurality of first charging profiles corresponding to respective amount of degradation of the particular battery.

9. The method according to claim 8 , the determining of the second set of parameters used to adapt the second charging profile further comprising:
calculating (i) a value of a fifth parameter in the second set of parameters of a first adaptation function configured to adapt the second parameter in the first set of parameters depending on an amount of degradation of the particular battery and (ii) a value of a sixth parameter in the second set of parameters of a second adaptation function configured to adapt the fourth parameter in the first set of parameters depending on an amount of degradation of the particular battery that:
minimizes differences between the plurality of first charging profiles and the second charging profile adapted based on the respective amounts of degradation of the particular battery corresponding to each charging profile in the plurality of first charging profiles; and
minimizes differences between a degradation of the particular battery caused by each first charging profile in the plurality of first charging profiles and a degradation of the particular battery caused by the second charging profile adapted based on the respective amounts of degradation of the particular battery corresponding to each charging profile in the plurality of first charging profiles.

10. The method according to claim 9 , wherein the first adaptation function is configured to adapt the second parameter in the first set of parameters depending on an amount of degradation of the particular battery and depending on a temperature of the battery.

11. The method according to claim 1 , wherein, for at least one charging phase in the ordered sequence, the respective first parameter has one of (i) a first value indicating that the charging current is to be held a constant current defined by the respective second parameter during the respective at least one charging phase, (ii) a second value indicating that a battery voltage of the particular battery is to be held a constant voltage defined by the respective second parameter during the respective at least one charging phase, (iii) a third value indicating that a rate of change of the charging current is to be held a constant rate of current change defined by the respective second parameter during the respective at least one charging phase, and (iv) a fourth value indicating that a rate of change of the battery voltage is to be held a constant rate of voltage change defined by the respective second parameter during the respective at least one charging phase.

12. The method according to claim 1 , wherein,

Assignees

• Bosch Gmbh Robert

Inventors

• Ramezan Pour Safaei Farshad
• Subbaraman Anantharaman
• Ravi Nikhil
• Klein Reinhardt
• Schmidt Gerd Simon
• Cheng Yongfang

Classifications

• H02J7/975

  in response to temperature · CPC title

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/84

  Control of state of health [SOH] · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/92 Primary

  with prioritisation of loads or sources · CPC title