Method and apparatus to monitor an on-vehicle battery charger

Patent metadata

Field	Value
Publication number	US-2016303983-A1
Application number	US-201514686874-A
Country	US
Kind code	A1
Filing date	Apr 15, 2015
Priority date	Apr 15, 2015
Publication date	Oct 20, 2016
Grant date	—

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.

First claim

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.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Rotay Robert
• Cooley Robert B
• Kumar Keith
• Hare William M
• Adrian Michael W

Classifications

• H02J2105/33

  exchanging power with road vehicles · CPC title

• H02J7/663

  using battery or load disconnect circuits (H02J9/002 takes precedence) · CPC title

• H02J7/84

  Control of state of health [SOH] · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/52

  for charge balancing, e.g. equalisation of charge between batteries · CPC title