METHOD FOR CHARGING A PLUG-IN ELECTRIC VEHICLE

• US 20130234664A1
• Filed: 03/09/2012
• Published: 09/12/2013
• Est. Priority Date: 03/09/2012
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Marus, James D., Newhouse, Vernon L.
• Granted Patent: US 9,013,143 B2
• Time in Patent Office: Days
• US Class Current: 320/109
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/62 charged by low-power generators primarily intended to support the batteries, e.g. range extenders
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 53/00 Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/51 Photovoltaic means
• CPC Class Codes: B60L 53/52 Wind-driven generators
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

An exemplary charging system and method for controlling a fast charging process involving an external power source (e.g., a high-voltage charging station providing 10 kW-300 kW of power) and a plug-in electric vehicle. In one embodiment, the charging method uses a costing function to estimate the negative impact each fast charging session has on battery life. If the overall negative impact of past and/or present charging sessions has exceeded some threshold, then the charging method may reduce charging parameters (e.g., limit the charging amperage, voltage, power, duration, etc.) in an effort to avoid further diminishing the battery life. Thus, the charging system and method enable a user to frequently engage in fast charging sessions with an external power source, yet minimize the impact that such sessions have on the battery.

Claims

1. A method for charging a plug-in electric vehicle with an external power source, comprising the steps of:

(a) gathering data related to one or more past or present charging sessions, and using the charging data to estimate a negative impact on a battery of the plug-in electric vehicle;

(b) comparing the negative impact on the battery of the plug-in electric vehicle to a negative impact threshold; and

(c) when the negative impact on the battery of the plug-in electric vehicle exceeds the negative impact threshold, then limiting the charging power that is provided by the external power source to the plug-in electric vehicle.

2. The method of claim 1, wherein step (a) further comprises gathering past charging data from memory located on the plug-in electric vehicle, where the past charging data is related to one or more past charging sessions and includes at least one piece of data selected from the group consisting of:

past charging parameters, past charging history, or past charging impact.

3. The method of claim 2, wherein step (a) further comprises gathering past charging data that includes a past impact number, and the past impact number is a quantitative value representative of the estimated negative impact of one or more past charging sessions on the battery.

4. The method of claim 1, wherein step (a) further comprises gathering present charging data, where the present charging data is related to a present charging session and includes at least one piece of data selected from the group consisting of:

present charging parameters, present charging history, or present charging impact.

5. The method of claim 4, wherein step (a) further comprises using the present charging data to determine a negative impact of the present charging session on the battery of the plug-in electric vehicle.

6. The method of claim 5, wherein step (a) further comprises adding the negative impact of the present charging session to a negative impact of one or more past charging sessions to determine an overall impact on the battery of the plug-in electric vehicle.

7. The method of claim 1, wherein step (a) further comprises gathering a present charging parameter from a sensor located on the plug-in electric vehicle, where the present charging parameter includes at least one piece of data selected from the group consisting of:

a temperature, a voltage, an amperage, a power level, a rate of charge, a state of charge (SOC), or a C-rate.

8. The method of claim 7, wherein step (a) further comprises using the present charging parameter to determine an instantaneous impact number that represents the impact that the present charging session is having on the battery at that time.

9. The method of claim 8, wherein a look-up table uses the present charging parameter as an input and provides the instantaneous impact number as an output.

10. The method of claim 8, wherein step (a) further comprises integrating the instantaneous impact number over the duration of the present charging session to determine a present impact number that represents the cumulative impact of the present charging session.

11. The method of claim 9, wherein step (a) further comprises adding the present impact number for the present charging session to a past impact number for one or more past charging sessions to determine an overall impact number that represents the total impact of both past and present charging sessions.

12. The method of claim 11, wherein the past impact number for one or more past charging sessions is devalued or reduced in weighting based on how long ago they occurred.

13. The method of claim 1, wherein step (b) further comprises comparing an overall impact number that represents the total impact of both past and present charging sessions to a negative impact threshold that represents the level where further fast charging is likely to have an unacceptable negative impact on the battery of the plug-in electric vehicle.

14. The method of claim 1, wherein when the negative impact on the battery exceeds the negative impact threshold, then step (c) further comprises limiting the charging power that is provided by the external power source to the plug-in electric vehicle by sending command signals from a control module located on the plug-in electric vehicle to the external power source that instructs the external power source to decrease the charging amperage.

15. The method of claim 14, wherein a look-up table uses an overall impact number as an input and provides a decreased charging power as an output.

16. The method of claim 1, wherein the method further comprises the step:

using a power coupler to determine if the plug-in electric vehicle is connected to an external high-voltage power source that provides between 10 kW-300 kW of electrical power.

17. The method of claim 1, wherein the external power source is an external high-voltage power source that provides between 10kW-300 kW of electrical power.

18. A charging system for charging a plug-in electric vehicle with an external power source, comprising:

a power connection for connecting the plug-in electric vehicle to the external power source;

isolation hardware coupled to the power connection, the isolation hardware isolates electrical power provided by the external power source;

a battery coupled to the isolation hardware, the battery provides the plug-in electric vehicle with electrical power for vehicle propulsion;

one or more sensor(s) for providing data related to a charging session; and

a control module coupled to the sensor(s), wherein the control module is configured to use the charging data to estimate a negative impact on the battery from charging with the external power source, and to limit the charging power that is provided by the external power source to the plug-in electric vehicle when the negative impact on the battery exceeds some negative impact threshold.