TEST SYSTEM AND METHOD FOR TESTING A BATTERY PACK

• US 20170074944A1
• Filed: 09/15/2015
• Published: 03/16/2017
• Est. Priority Date: 09/15/2015
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Fadel, Fouad, Lee, Dalhoon
• Granted Patent: US 10,371,758 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking
• CPC Class Codes: G01R 31/371 with remote indication, e.g. on external chargers
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A test system for testing a battery pack having a high voltage terminal, a low voltage terminal, first and second battery modules, and a master microprocessor is provided. The test system includes an inverter unit and a test computer. The inverter unit iteratively grounds the high voltage terminal and the low voltage terminal. The test computer sends a first message to the master microprocessor that requests first and second voltage values of the first and second battery modules. The master microprocessor sends a second message having the first and second voltage values to the test computer which determines a first voltage deviation value. The test computer sets a test flag to a predetermined pass value if the test computer received the second message and the first voltage deviation value is less than a first threshold voltage deviation value.

Claims

1. A test system for testing a battery pack, the battery pack having a high voltage terminal, a low voltage terminal, first and second battery modules, and a master microprocessor, the test system comprising:

an inverter unit electrically coupled to both the high voltage terminal and the low voltage terminal, the inverter unit iteratively grounding the high voltage terminal and the low voltage terminal of the battery pack over a time interval;

a test computer operably coupled to the master microprocessor, the test computer programmed to send a first message to the master microprocessor during the time interval that requests first and second voltage values, indicating first and second output voltages, respectively, of the first and second battery modules, respectively;

the master microprocessor programmed to send a second message having the first and second voltage values, to the test computer, if the master microprocessor received the first message;

the test computer further programmed to determine a first voltage deviation value based on the first and second voltage values, if the test computer received the second message; and

the test computer further programmed to set a test flag to a predetermined pass value indicating the battery pack is operating correctly, if the test computer received the second message and the first voltage deviation value is less than a first threshold voltage deviation value.

2. The test system of claim 1, wherein the test computer determines the first voltage deviation value by determining an absolute value of a difference between the first and second voltage values.

3. The test system of claim 1, wherein:

the test computer further programmed to send a third message to the master microprocessor during the time interval that requests a pack voltage value that indicates a third output voltage between the high voltage terminal and the low voltage terminal;

the master microprocessor further programmed to send a fourth message having the pack voltage value to the test computer, if the master microprocessor received the third message;

the test computer further programmed to determine a second voltage deviation value based on the pack voltage value and a sum of the first and second voltage values, if the test computer received the fourth message; and

the test computer further programmed to set the test flag to the predetermined pass value indicating the battery pack is operating correctly, if the test computer received the second and fourth messages, and the first voltage deviation value is less than the first threshold voltage deviation value, and the second voltage deviation value is less than a second threshold voltage deviation value.

4. The test system of claim 1, wherein the test computer determines the second voltage deviation value by determining an absolute value of a difference between the pack voltage value and the sum of the first and second voltage values.

5. The test system of claim 1, further comprising a function generator operably coupled to the inverter unit, the function generator generating a pulse width modulated signal to induce the inverter unit to iteratively ground the high voltage terminal and the low voltage terminal of the battery pack over the time interval.

6. The test system of claim 1, further comprising a power supply operably coupled to the master microprocessor, the power supply supplying an operational voltage to the master microprocessor.

7. The test system of claim 1, wherein the test computer is disposed external of a housing of the battery pack.

8. The test system of claim 1, wherein the inverter unit iteratively grounds the high voltage terminal and the low voltage terminal of the battery pack to a vehicle chassis over the time interval.

9. A method for testing a battery pack, the battery pack having a high voltage terminal, a low voltage terminal, first and second battery modules, and a master microprocessor, the method comprising:

providing an inverter unit electrically coupled to both the high voltage terminal and the low voltage terminal of the battery pack;

providing a test computer operably coupled to the master microprocessor;

iteratively grounding the high voltage terminal and the low voltage terminal of the battery pack over a time interval utilizing the inverter unit;

sending a first message to the master microprocessor from the test computer during the time interval that requests first and second voltage values, indicating first and second output voltages, respectively, of the first and second battery modules, respectively;

sending a second message having the first and second voltage values from the master microprocessor to the test computer, if the master microprocessor received the first message;

determining a first voltage deviation value based on the first and second voltage values utilizing the test computer, if the test computer received the second message; and

setting a test flag to a predetermined pass value indicating the battery pack is operating correctly utilizing the test computer, if the test computer received the second message and the first voltage deviation value is less than a first threshold voltage deviation value.

10. The method of claim 9, further comprising:

sending a third message to the master microprocessor from the test computer during the time interval that requests a pack voltage value that indicates a third output voltage between the high voltage terminal and the low voltage terminal;

sending a fourth message having the pack voltage value to the test computer from the master microprocessor, if the master microprocessor received the third message;

determining a second voltage deviation value based on the pack voltage value and a sum of the first and second voltage values utilizing the test computer, if the test computer received the fourth message; and

setting the test flag to the predetermined pass value indicating the battery pack is operating correctly utilizing the test computer, if the test computer received the second and fourth messages, and the first voltage deviation value is less than the first threshold voltage deviation value, and the second voltage deviation value is less than a second threshold voltage deviation value.