Apparatus and method for diagnosing positive electrode contactor of battery pack

1. An apparatus for diagnosing a positive electrode contactor of a battery pack, wherein the battery pack includes the positive electrode contactor provided on a charge-discharge path connected to a positive electrode terminal of the battery pack and a negative electrode contactor provided on a second charge-discharge path connected to a negative electrode terminal of the battery pack, the apparatus configured to:

measure a first measurement voltage applied between a ground and a first node to which a positive electrode terminal of a battery module included in the battery pack and a first end of the positive electrode contactor are both connected; and

measure a second measurement voltage applied between the ground and a second node to which a negative electrode terminal of the battery module and a first end of the negative electrode contactor are both connected, the apparatus comprising;

a positive electrode protection capacitor located between the ground and the positive electrode terminal of the battery pack;

a negative electrode protection capacitor located between the ground and the negative electrode terminal of the battery pack; and

a processor coupled to a plurality of diagnosis circuits configured to selectively connect two of the first node, the second node, a third node to which a second end of the positive electrode contactor and a first end of the positive electrode protection capacitor are both connected, a fourth node to which a second end of the negative electrode contactor and a first end of the negative electrode protection capacitor are both connected, and the ground,

wherein the processor is configured to:

measure a first diagnosis voltage applied between the third node and the second node,

measure a second diagnosis voltage applied to the positive electrode protection capacitor;

measure a third diagnosis voltage applied to the negative electrode protection capacitor;

diagnose whether the battery module is electrically leaky based on the first measurement voltage and the second measurement voltage, and

diagnose whether the positive electrode contactor is short-circuited based on at least one of the first diagnosis voltage, the second diagnosis voltage or the third diagnosis voltage.

2. The apparatus for diagnosing a positive electrode contactor of a battery pack according to claim 1 , wherein the plurality of diagnosis circuits comprises:

a first diagnosis circuit connected between the third node and the second node and configured to measure the first diagnosis voltage between the third node and the second node;

a second diagnosis circuit connected between the third node and the ground and configured to measure the second diagnosis voltage between the third node and the ground; and

a third diagnosis circuit connected between the fourth node and the ground and configured to measure the third diagnosis voltage between the fourth node and the ground.

3. The apparatus for diagnosing a positive electrode contactor of a battery pack according to claim 2 ,

wherein the first diagnosis circuit includes a first voltage dividing circuit having a first protection resistor and a first detection resistor to divide the first diagnosis voltage and a first switch for applying a voltage to the first voltage dividing circuit in response to a first control signal output from the processor,

wherein the second diagnosis circuit includes a second voltage dividing circuit having a second protection resistor and a second detection resistor to divide the second diagnosis voltage and a second switch for applying a voltage to the second voltage dividing circuit in response to a second control signal output from the processor, and

wherein the third diagnosis circuit includes a third voltage dividing circuit having a third protection resistor and a third detection resistor to divide the third diagnosis voltage and a third switch for applying a voltage to the third voltage dividing circuit in response to a third control signal output from the processor.

4. The apparatus for diagnosing a positive electrode contactor of a battery pack according to claim 3 ,

wherein the first voltage measuring unit includes a fourth voltage dividing circuit having a fourth protection resistor and a fourth detection resistor to divide the first measurement voltage and a fourth switch for applying a voltage to the fourth voltage dividing circuit in response to a fourth control signal output from the processor, and

wherein the second voltage measuring unit includes a fifth voltage dividing circuit having a fifth protection resistor and a fifth detection resistor to divide the second measurement voltage and a fifth switch for applying a voltage to the fifth voltage dividing circuit in response to a fifth control signal output from the processor.

5. The apparatus for diagnosing a positive electrode contactor of a battery pack according to claim 4 ,

wherein the processor is configured to:

control the fourth switch and the first switch into a closed state during a first switching cycle,

control the fifth switch into an open state during the first switching cycle,

control the fourth switch into an open state during a second switching cycle,

control the fifth switch and the first switch into a closed state during the second switching cycle, and

measure the first diagnosis voltage, the second diagnosis voltage and the third diagnosis voltage during each of the first switching cycle and the second switching cycle.

6. The apparatus for diagnosing a positive electrode contactor of a battery pack according to claim 5 ,

wherein the processor is configured to determine that the positive electrode contactor is in a normal state without a short circuit when the first diagnosis voltage has a positive value during the first switching cycle, an absolute value of the first diagnosis voltage gradually decreases during the first switching cycle, the first diagnosis voltage has a negative value during the second switching cycle, and an absolute value of the first diagnosis voltage gradually decreases during the second switching cycle.

7. The apparatus for diagnosing a positive electrode contactor of a battery pack according to claim 5 ,

wherein the processor is configured to determine that the positive electrode contactor is in a fault state with a short circuit when the first diagnosis voltage has a positive value and is kept constantly during each of the first switching cycle and the second switching cycle.

8. The apparatus for diagnosing a positive electrode contactor of a battery pack according to claim 7 ,

wherein the processor is configured to determine that the positive electrode contactor is in the fault state with the short circuit when the second diagnosis voltage has a value of 0 or more and when a difference between a voltage value of the second diagnosis voltage and a voltage value of the third diagnosis voltage gradually decreases during each of the first switching cycle and the second switching cycle.

9. A battery pack, comprising an apparatus for diagnosing a positive electrode contactor of a battery pack according to claim 1 .

10. A method for diagnosing a positive electrode contactor of a battery pack, wherein the battery pack includes the positive electrode contactor provided on a first charge-discharge path connected to a positive electrode terminal of the battery pack and a negative electrode contactor provided on a second charge-discharge path connected to a negative electrode terminal of the battery pack, the method comprising:

measuring a first measurement voltage applied between a ground and a first node to which a positive electrode terminal of a battery module included in the battery pack and a first end of the positive electrode contactor are both connected;

measuring a second measurement voltage applied between the ground and a second node to which a negative electrode terminal of the battery module and a first end of the negative electrode contactor are both connected;

measuring a first diagnosis voltage applied between the second node and a third node to which a second end of the positive electrode contactor and a first end of a positive electrode protection capacitor are both connected;

measuring a second diagnosis voltage applied to the positive electrode protection capacitor located between the ground and the positive electrode terminal of the battery pack;

measuring a third diagnosis voltage applied to a negative electrode protection capacitor located between the ground and the negative electrode terminal of the battery pack;

diagnosing whether the battery module is electrically leaky based on the first measurement voltage and the second measurement voltage;

diagnosing whether the positive electrode contactor is short-circuited based on at least one of the first diagnosis voltage, the second diagnosis voltage or the third diagnosis voltage.