Apparatus for diagnosing relay failure of battery using parallel circuit for constant power supply and method thereof

Patent metadata

Field	Value
Publication number	US-10753975-B2
Application number	US-201716094175-A
Country	US
Kind code	B2
Filing date	Dec 12, 2017
Priority date	Dec 12, 2016
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

Disclosed is an apparatus and method for diagnosing a failure of a relay for a battery required to constantly supply the power to a vehicle with guaranteeing the constant power supply using a parallel circuit. The apparatus of the present disclosure includes a control unit which when voltage and current of a parallel unit is 0 in first state in which a relay unit is in closed state and the parallel unit is in open state, controls into second state in which the relay unit is in closed state and the parallel unit is in closed state, and when the voltage of the parallel unit is equal to voltage of the battery and the current of the parallel unit is 0 in the second state, controls into third state in which the relay unit is in open state and the parallel unit is in closed state, and when the current of the parallel unit is equal to current of the relay unit in the third state, determines a switch of the relay unit to be normal, and when the current of the parallel unit is 0, determines the switch of the relay unit to be faulty, a relay unit through which the current of the battery flows in closed state of the switch to supply the power, and a parallel unit which applies the current of the battery in closed state instead of the relay unit in open state in which the power supply is stopped.

First claim

What is claimed is:

1. An apparatus, comprising:
a relay unit including a switch;
a parallel unit including a switch; and
a control unit which controls into first state in which the relay unit is in closed state and the parallel unit is in an open state, and when voltage and current of the parallel unit is 0 in the first state, controls into second state in which the relay unit is in closed state and the parallel unit is in closed state, and when the voltage of the parallel unit is equal to voltage of a battery and the current of the parallel unit is 0 in the second state, controls into third state in which the relay unit is in open state and the parallel unit is in closed state, and when the current of the parallel unit is equal to current of the battery and the voltage of the parallel circuit is equal to voltage of the battery in the third state, determines the switch of the relay unit to be normal, and when the current of the parallel unit is 0, determines the switch of the relay unit to be faulty,
wherein the relay unit switches the switch of the relay unit to open or closed state by control of the control unit, the relay unit through which the current of the battery flows in closed state to supply power, and
wherein the parallel unit switches the switch of the parallel circuit to open or closed state by control of the control unit, and applies the current of the battery in closed state instead of the relay unit in open state in which the supply of power is stopped;
a parallel unit voltage sensing unit which senses the voltage of the parallel unit and outputs the same to the control unit; and
a parallel unit current sensing unit which senses the current of the parallel unit and outputs the same to the control unit.

2. The apparatus according to claim 1 , further comprising:
a battery current sensing unit which senses the current of the battery and outputs the same to the control unit,
wherein when the control unit determines that the current of the battery received in the first state is equal to or less than a preset current, the control unit starts determining whether to control into the second state.

3. The apparatus according to claim 2 , wherein the apparatus is a Battery Management System (BMS) apparatus of an automotive battery installed in a vehicle, and
when the received current of the battery is equal to or less than the preset current, the control unit determines that the vehicle is in parking state, and starts determining whether to control into the second state.

4. The apparatus according to claim 1 , wherein the control unit controls the relay unit into closed state to maintain constant power supply of the battery, and
if necessary, in a state that the control unit controls the parallel unit into closed state, the control unit controls the relay unit into open state.

5. The apparatus according to claim 1 , wherein when the control unit determines that the current of the parallel unit is not 0 in the controlled second state, the control unit determines that the switch of the relay unit is faulty in eternal open state.

6. The apparatus according to claim 1 , further comprising:
a battery voltage sensing unit which senses the voltage of the battery and outputs the same to the control unit,
wherein when the voltage of the parallel unit is equal to the voltage of the battery and the current of the parallel unit is 0 in the controlled second state, the control unit determines the second state to be normal.

7. The apparatus according to claim 6 , wherein in the second state, because resistance of the relay unit is smaller than resistance of the parallel unit and the current of the battery flows through the relay unit, the sensed current of the parallel unit is 0.

8. The apparatus according to claim 1 , wherein the control unit receives inputs of voltage and current of the parallel unit in the controlled third state, and when the voltage of the parallel unit is equal to the voltage of the battery and the current of the parallel unit is equal to the current of the battery, the control unit determines the third state to be normal.

9. The apparatus according to claim 8 , wherein in the third state, because the current of the battery flows through the parallel unit instead of the relay unit in open state, the current of the parallel unit is equal to the current of the battery.

10. The apparatus according to claim 1 , wherein when the current of the parallel unit is not equal to the current of the battery in the third state, the control unit determines that the switch of the relay unit is faulty in eternal closed state.

11. The apparatus according to claim 1 , further comprising:
a diode unit connected to the parallel unit to prevent backward voltage,
wherein the current outputted from the parallel unit flows to an output terminal of the relay unit through the diode unit.

12. A battery management system (BMS) apparatus for diagnosing a failure of a relay required for constant power output of a battery, the BMS apparatus comprising:
a relay circuit including a switch;
a parallel circuit including a switch; and
a control unit which controls into first state in which the relay circuit is in closed state and the parallel circuit is in open state, and when voltage and current of the parallel circuit is 0 in the first state, controls into second state in which the relay circuit is in closed state and the parallel circuit is in closed state, and when the voltage of the parallel circuit is equal to voltage of the battery and the current of the parallel circuit is 0 in the second state, controls into third state in which the relay circuit is in open state and the parallel circuit is in closed state, and when the current of the parallel circuit is equal to a current of the battery and the voltage of the parallel circuit is equal to voltage of the battery in the third state, determines a switch of the relay circuit to be normal, and when the current of the parallel circuit is 0, determines the switch of the relay circuit to be faulty
wherein the relay circuit switches the switch of the relay circuit to open or closed state by control of the control unit, the relay circuit through which the current of the battery flows in closed state to supply the power, and
wherein the parallel circuit is connected to an input terminal of the relay circuit, the parallel circuit switches the switch of the parallel circuit to open or closed state by control of the control unit, and applies the current of the battery in closed state instead of the relay circuit in which the supply of power is stopped;
a voltage sensing circuit connected to an output terminal of the parallel circuit to sense the voltage of the parallel circuit and outputs the same to the control unit; and
a current sensing circuit connected to the output terminal of the parallel circuit to sense the current of the parallel circuit and outputs the same to the control unit.

13. A method for diagnosing a failure of a relay required for constant power output by an apparatus, the method comprising:
controlling into first state in which a switch of a relay circuit is in closed state and a switch of a parallel circuit is in open state;
determining the first state to be normal when the sensed voltage and current of the parallel circuit is 0 in the controlled first state;
controlling into second state in which the relay circuit is in closed state and the parallel circuit is in closed state when the first state is determined to be normal;
determining the second state to be normal when the sensed voltage of the parallel circuit is equal to voltage of a battery and the current of the parallel circuit is

Assignees

• Lg Chemical Ltd

Inventors

• Park Jong-Il
• Gil You-Seob
• An Sun-Mo

Classifications

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02J7/00

  Circuit arrangements for charging or discharging batteries or for supplying loads from batteries · CPC title

• G01R31/396

  Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery · CPC title

• H01M10/425

  Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00) · CPC title