Real-time modification of charge termination voltage and current and associated controls for electric vehicles

Patent metadata

Field	Value
Publication number	US-2024166070-A1
Application number	US-202217990808-A
Country	US
Kind code	A1
Filing date	Nov 21, 2022
Priority date	Nov 21, 2022
Publication date	May 23, 2024
Grant date	—

Abstract

A charging system for an electric vehicle includes: a memory configured to store terminal clamp voltage (CV) and a cutoff current (CC) combination pairs; a charging receptacle configured to connect to an offboard charging station; and an onboard charging circuit. The onboard charging circuit includes: a high-voltage direct current bus connected to a rechargeable energy storage system; and a control module configured to communicate with the offboard charging station and determine charging capabilities of the offboard charging station and the onboard charging circuit, to select one of the CV and CC combination pairs based on the charging capabilities of the offboard charging station and the onboard charging circuit, and to initiate charging of the rechargeable energy storage system based on the selected one of the CV and CC combination pairs.

First claim

What is claimed is:

1 . A charging system for an electric vehicle, the charging system comprising:
a memory configured to store a plurality of terminal clamp voltage (CV) and a cutoff current (CC) combination pairs; a charging receptacle configured to connect to an offboard charging station; and an onboard charging circuit comprising
a high-voltage direct current bus connected to a rechargeable energy storage system, and
a control module configured to communicate with the offboard charging station and determine charging capabilities of the offboard charging station and the onboard charging circuit, to select one of the plurality of CV and CC combination pairs based on the charging capabilities of the offboard charging station and the onboard charging circuit, and to initiate charging of the rechargeable energy storage system based on the selected one of the plurality of CV and CC combination pairs.

2 . The charging system of claim 1 , further comprising an onboard charging module configured to:
convert an alternating current voltage received from the offboard charging station via the charging receptacle to a direct current voltage and supply the direct current voltage to the high-voltage direct current bus; indicate to the control module the alternative current voltage; and receive an instruction from the control module to convert the alternating current voltage to the CV of the one of the plurality of CV and CC combination pairs for charging the rechargeable energy storage system.

3 . The charging system of claim 1 , wherein the control module is configured to:
look up or calculate an estimated charge power value for each of at least some of the plurality of CV and CC combination pairs to provide a plurality of charge power values; and based on the plurality of charge power values, select the one of the plurality of CV and CC combination pairs with the estimated charge power closest to but not greater than a smaller of a) a power capability of the offboard charging station, and b) a power capability of the onboard charging circuit.

4 . The charging system of claim 1 , wherein the control module is configured to:
determine a depth of discharge; look up or calculate an estimated life expectancy of the rechargeable energy storage system for each of at least some of the plurality of CV and CC combination pairs; and based on the depth of discharge, select the one of the plurality of CV and CC combination pairs resulting in a rechargeable energy storage system life expectancy being closest to a target life expectancy without being shorter than the target life expectancy.

5 . The charging system of claim 1 , wherein the control module is configured to:
estimate at least one of resistance uncertainty and growth of the rechargeable energy storage system; based on the at least one of resistance uncertainty and growth, look up or calculate estimated charge termination state of charge uncertainty of the rechargeable energy storage system for each of at least some of the plurality of CV and CC combination pairs; and based on the estimated charge termination state of charge uncertainties, select the one of the plurality of CV and CC combination pairs resulting in a charge termination state of charge uncertainty being closet to a target charge termination state of charge uncertainty without exceeding the target charge termination state of charge uncertainty.

6 . The charging system of claim 1 , wherein the control module is configured to:
for each of at least some of the plurality of CV and CC combination pairs,
estimate a change in resistance of the rechargeable energy storage system,
estimate an open circuit voltage based on the change in resistance and current supplied to the rechargeable energy storage system,
estimate state of charge based on the estimated open circuit voltage, and
determine a state of charge error based on the estimated state of charge and a target state of charge; and
select the one of the plurality of CV and CC combination pairs with a highest corresponding power and having a state of charge error within a set error range.

7 . The charging system of claim 1 , wherein the control module is configured to:
determine whether the offboard charging station is a public station; determine whether the offboard charging station has a time-based cost for charging; in response to determining the offboard charging station being a public station and having a time-based cost for charging, look up or calculate estimated charge power values for each of at least some of the plurality of CV and CC combination pairs to provide a plurality of charge power values; and based on the plurality of charge power values, select the one of the plurality of CV and CC combination pairs with the estimated charge power closest to but not greater than a smaller of a) a power capability of the offboard charging station, and b) a power capability of the onboard charging circuit.

8 . The charging system of claim 1 , wherein the control module is configured to:
determine whether the offboard charging station is a public station; in response to determining that the offboard charging station is a public station, implement a charge time minimization method to select the one of the plurality of CV and CC combination pairs; and in response to determining that the offboard charging station is not a public station, implement a maximum life charging method to select one of the plurality of CV and CC combination pairs.

9 . The charging system of claim 1 , wherein the control module is configured to:
determine a depth of discharge; determine a resistance uncertainty or growth of the rechargeable energy storage system; based on the depth of discharge, filter out some of the plurality of CV and CC combination pairs that do not satisfy a life requirement for the rechargeable energy storage system to provide a first resultant set of CV and CC combination pairs; filter out some of the first resultant set of CV and CC combination pairs that do not satisfy a state of charge accuracy requirement to provide a second resultant set of CV and CC combination pairs; and implement a charge time minimization method to select the one of the plurality of CV and CC combination pairs from the second resultant set of CV and CC combination pairs.

10 . The charging system of claim 1 , wherein the control module is configured to:
determine whether the offboard charging station is a direct current charging station or an alternating current charging station; in response to the offboard charging station being a direct current charging station, instruct the offboard charging station to charge the rechargeable energy storage system based on the selected CV and CC combination pair; and in response to the offboard charging station being an alternating current charging station, charge the rechargeable energy storage system based on the selected CV and CC combination pair.

11 . A method of charging a rechargeable energy storage system of an electric vehicle, the method comprising:
storing a plurality of terminal clamp voltage (CV) and a cutoff current (CC) combination pairs; transferring power between an offboard charging station and a high-voltage direct current bus of an onboard charging circuit of the electric vehicle, the high-voltage direct current bus being connected to a rechargeable energy storage system; communicating with the offboard charging station and determining charging capabilities of the offboard charging station and the onboard charging circuit; selecting one of the plurality of CV and CC combination pairs based on the charging capabilities of the offboard charging st

Assignees

• Gm Global Tech Operations Llc

Inventors

• Bunnell Justin
• Lyons John C
• Inguva Sudhakar
• Moulliet Ryan B

Classifications

• B60L53/16

  Connectors, e.g. plugs or sockets, specially adapted for charging electric vehicles · CPC title

• B60L53/14

  Conductive energy transfer · CPC title

• B60L53/30

  Constructional details of charging stations · CPC title

• B60L53/665

  Methods related to measuring, billing or payment · CPC title

• B60L53/62 Primary

  in response to charging parameters, e.g. current, voltage or electrical charge · CPC title