Relay state management apparatus and operating method thereof
A relay state management apparatus including a switch connected to an end of a battery module, a resistor unit connected to the switch, a voltage measuring unit measuring a voltage applied to the resistor unit, a relay connected between the battery module and a load, and a controller controlling the switch and the relay to be short-circuited and diagnosing a state of the relay based on the voltage measured by the voltage measuring unit.
1. A relay state management apparatus comprising:
a circuit for supplying power from a battery module to a load, the circuit comprising:
a switch connected to an end of the battery module;
one or more resistors connected to the switch;
a voltage sensor measuring a voltage applied to the one or more resistors;
a relay connected between the battery module and the load along an electrical path;
a capacitor connected to the electrical path between a node of the electrical path and ground; and
a controller configured to:
control the switch and the relay to be short-circuited for a predetermined duration;
calculate a voltage difference between the voltage measured by the voltage sensor at a beginning of the predetermined duration and the voltage measured by the voltage sensor at an end of the predetermined duration;
diagnose a state of the relay based on the calculated voltage difference.
2. The relay state management apparatus of claim 1 , wherein the controller is configured to diagnose the state of the relay based on the calculated voltage difference and a reference change amount that is an amount of change in the voltage previously measured by the voltage sensor for a second predetermined duration beginning from when the controller controls the switch to be short-circuited in an open state of the relay.
3. The relay state management apparatus of claim 2 , wherein the controller is configured to:
diagnose the state of the relay as faulty in response to the calculated voltage difference being greater than or equal to a value obtained by multiplying the reference change amount by a predetermined rate; and
diagnose the state of the relay as normal in response to the calculated voltage difference being less than the value obtained by multiplying the reference change amount by the predetermined rate.
4. The relay state management apparatus of claim 1 , wherein the controller is configured to diagnose the state of the relay based on the calculated voltage difference and a reference change amount that is an amount of change in the voltage previously measured by the voltage sensor for a duration beginning from when the controller controls the switch to be short-circuited in a short-circuited state of the relay.
5. The relay state management apparatus of claim 4 , wherein the controller is configured to:
diagnose the state of the relay as normal in response to the calculated voltage difference being within a predetermined range from the reference change amount; and
diagnose the state of the relay as faulty in response to the calculated voltage difference being out of the predetermined range from the reference change amount.
6. The relay state management apparatus of claim 1 , wherein the one or more resistors comprises at least two resistors including a first resistor and a second resistor that are serially connected to each other.
7. The relay state management apparatus of claim 6 , wherein the voltage sensor is configured to measure a voltage applied to the second resistor.
8. The relay state management apparatus of claim 1 , wherein the switch is connected to an anode terminal of the battery module.
9. An operating method of a relay state management apparatus, the operating method comprising:
controlling operation of a switch included in a circuit for supplying power from a battery module to a load, wherein the switch is connected between the battery module and one or more resistors included in the circuit;
controlling operation of a relay connected between the battery module and the load along an electrical path, wherein controlling operation of the switch and the relay comprises controlling the switch and the relay to be short-circuited for a predetermined duration;
measuring, using a voltage sensor included in the circuit, a first voltage applied to the one or more resistors at a beginning of the predetermined duration and a second voltage applied to the one or more resistors at an end of the predetermined duration, wherein the first voltage changes to the second voltage over the predetermined duration at least in part as a function of a capacitor connected to the electrical path between a node of the electrical path and ground;
calculating a voltage difference between the measured first voltage and the measured second voltage; and
diagnosing a state of the relay based on the calculated voltage difference.
10. The operating method of claim 9 , wherein diagnosing the state of the relay based on the calculated voltage difference comprises:
diagnosing the state of the relay based on the calculated voltage difference and a reference change amount obtained by previously measuring an amount of change in voltage applied to the one or more resistors for a second predetermined duration beginning from when the switch is short-circuited in an open state of the relay.
11. The operating method of claim 10 , further comprising calculating a value by multiplying the reference change amount by a predetermined rate, wherein diagnosing the state of the relay comprises diagnosing whether the state of the relay is faulty or normal depending on whether the calculated voltage difference is at least or less than the calculated value, respectively.
12. The operating method of claim 9 , wherein diagnosing the state of the relay based on the calculated voltage difference comprises:
diagnosing the state of the relay based on the calculated voltage difference and a reference change amount obtained by previously measuring an amount of change in voltage applied to the one or more resistors for a second predetermined duration beginning from when the switch is short-circuited in a short-circuited state of the relay.
13. The operating method of claim 12 , wherein diagnosing the state of the relay comprises diagnosing whether the state of the relay is normal or faulty depending on whether the calculated voltage difference is within or outside of a predetermined range from the reference change amount, respectively.