Method and apparatus to monitor an on-vehicle battery charger

• US 9,643,502 B2
• Filed: 04/15/2015
• Issued: 05/09/2017
• Est. Priority Date: 04/15/2015
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Rotay, Robert, Cooley, Robert B., Kumar, Keith, Hare, William M., Adrian, Michael W.
• Primary Examiner(s): PELTON, NATHANIEL R
• Application Number:
  US14/686,874
• Publication Number:
  US 20160303983A1
• Time in Patent Office: 755 Days
• Field of Search: 320109
• 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 53/51 Photovoltaic means
• CPC Class Codes: B60L 53/52 Wind-driven generators
• CPC Class Codes: B60L 53/57 Charging stations without connection to power networks
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• 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 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A method for monitoring an on-vehicle battery charger includes estimating a charging efficiency of the battery charger. Upon achieving an indeterminate result related to the estimated charging efficiency of the battery charger, a commanded input power to the battery charger and an electric power at the on-vehicle battery during operation of the battery charger are determined. Flow of electric current through the battery charger is interrupted, and electric power flow from the on-vehicle battery is determined. An active charging efficiency of the battery charger is determined based upon the commanded input power to the battery charger, the electric power at the on-vehicle battery during operation of the battery charger and the monitored electric power flow from the on-vehicle battery when the flow of electric current through the battery charger is interrupted. Charging performance of the battery charger is evaluated based upon the active charging efficiency.

Claims

1. A method for monitoring an on-vehicle battery charger electrically coupling an off-vehicle electrical power source to an on-vehicle battery, the method comprising:

estimating a charging efficiency of the battery charger during battery charging; and

upon achieving an indeterminate result related to the estimated charging efficiency of the battery charger;

determining a commanded input power to the battery charger and determining an electric power at the on-vehicle battery during operation of the battery charger, and then,

interrupting flow of electric current through the battery charger,

monitoring electric power flow from the on-vehicle battery when the flow of electric current through the battery charger is interrupted,

determining an active charging efficiency of the battery charger based upon the commanded input power to the battery charger, the electric power at the on-vehicle battery during operation of the battery charger and the monitored electric power flow from the on-vehicle battery when the flow of electric current through the battery charger is interrupted, and

evaluating charging performance of the battery charger based upon the active charging efficiency.

2. The method of claim 1, wherein estimating a charging efficiency of the battery charger further comprises:

estimating an output power from the battery charger and estimating an input power to the battery charger, and

estimating the charging efficiency of the battery charger based upon the estimated output power from the battery charger and the estimated input power to the battery charger.

3. The method of claim 2, wherein estimating the input power to the battery charger comprises determining a magnitude of electric current commanded through the battery charger.

4. The method of claim 2, wherein estimating the output power from the battery charger comprises determining a net DC power at the battery and estimating a minimum electrical power flow to on-vehicle loads.

5. The method of claim 1, wherein estimating the charging efficiency of the battery charger during battery charging further comprises passively estimating the charging efficiency of the battery charger during battery charging.

6. The method of claim 1, wherein estimating the charging efficiency of the battery charger further comprises periodically estimating the charging efficiency of the battery charger.

7. The method of claim 1, wherein evaluating the charging performance of the battery charger based upon the active charging efficiency further comprises detecting a fault in the battery charger when the active charging efficiency is less than a low efficiency threshold.

8. The method of claim 1, wherein evaluating the charging performance of the battery charger based upon the active charging efficiency further comprises detecting a fault in the battery charger when the active charging efficiency is greater than a high efficiency threshold.

9. The method of claim 1, wherein monitoring electric power flow from the on-vehicle battery when the flow of electric current through the battery charger is interrupted further comprises monitoring electric power flow from the on-vehicle battery to on-vehicle loads when the flow of electric current through the battery charger is interrupted.

10. A method for monitoring an on-vehicle battery charger electrically coupling an off-vehicle electrical power source to an on-vehicle battery, the method comprising:

determining a commanded input power to the battery charger and determining an electric power at the on-vehicle battery during operation of the battery charger; and

then,

interrupting flow of electric current through the battery charger;

monitoring electric power flow from the on-vehicle battery when the flow of electric current through the battery charger is interrupted;

determining an active charging efficiency of the battery charger based upon the commanded input power to the battery charger, the electric power at the on-vehicle battery during operation of the battery charger and the monitored electric power flow from the on-vehicle battery when the flow of electric current through the battery charger is interrupted; and

evaluating charging performance of the battery charger based upon the active charging efficiency.

11. The method of claim 10, further comprising executing the method for monitoring the on-vehicle battery charger in response to an execution command originating from a hand-held scan tool.

12. The method of claim 10, wherein evaluating the charging performance of the battery charger based upon the active charging efficiency further comprises detecting a fault in the battery charger when the active charging efficiency is less than a low efficiency threshold.

13. The method of claim 10, wherein evaluating the charging performance of the battery charger based upon the active charging efficiency further comprises detecting a fault in the battery charger when the active charging efficiency is greater than a high efficiency threshold.

14. A high voltage electric circuit for a vehicle, comprising:

an on-vehicle battery charger couplable to an off-vehicle electrical power source;

a high-voltage bus electrically connected to an on-vehicle battery;

a plurality of on-vehicle loads electrically connected to the high-voltage bus; and

a controller including a control routine, said control routine executable to;

passively estimate a charging efficiency of the battery charger, and

upon achieving an indeterminate result related to the estimated charging efficiency of the battery charger,

determine a commanded input power to the battery charger and determining an electric power at the on-vehicle battery during operation of the battery charger, and then,

interrupt flow of electric current through the battery charger,

monitor electric power flow from the on-vehicle battery when the flow of electric current through the battery charger is interrupted,

determine an active charging efficiency of the battery charger based upon the commanded input power to the battery charger, the electric power at the on-vehicle battery during operation of the battery charger and the monitored electric power flow from the on-vehicle battery when the flow of electric current through the battery charger is interrupted, and

evaluate charging performance of the battery charger based upon the active charging efficiency.