# US 12,181,509 B2 · Insulation resistance detecting apparatus, system having the same, and method thereof

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- Number: US 12,181,509 B2
- Document ID: US12181509B2
- Status: Granted
- Kind: B2
- Application number: 17/483,012
- Filed: 2021-09-23
- Published: 2022-07-14
- Granted: 2024-12-31
- Earliest claimed: 2021-01-11
- Assignees: Hyundai Motor Company; Kia Corporation
- Applicants: Hyundai Motor Company; Kia Corporation
- Inventors: Hyo Jin Park; Soon Gil Kweon; Min Taek Kim
- Web page: https://patentgrep.com/patent/US12181509B2

## CPC

- B60L 3/0046: {relating to electric energy storage systems, e.g. batteries or capacitors}
- G01R 31/1227: {of components, parts or materials (G01R31/1209, G01R31/1218, G01R31/18 take precedence; circuits therefor G01R31/14; testing vessels of electrodes G01R31/16)}
- B60L 3/0053: {relating to fuel cells}
- B60W 50/0205: {Diagnosing or detecting failures; Failure detection models}
- H01M 8/04649: {of fuel cell stacks}
- H01M 8/04671: {of the individual fuel cell}
- H01M 8/04679: {of fuel cell stacks}
- H01M 8/04686: {of auxiliary devices, e.g. batteries, capacitors}
- H01M 10/48: Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569)
- H01M 16/006: {of fuel cells with rechargeable batteries}
- H01M 50/574: Devices or arrangements for the interruption of current
- B60L 2240/547: Voltage
- B60W 2510/242: for electrical energy
- H01M 2220/20: Batteries in motive systems, e.g. vehicle, ship, plane
- H01M 2250/20: Fuel cells in motive systems, e.g. vehicle, ship, plane
- Y02E 60/50: Fuel cells
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

An insulation resistance detection apparatus includes a processor configured to separate a fuel cell from a high voltage battery depending on an insulation resistance value of a vehicle during driving of the vehicle, and then to measure an insulation resistance value of the fuel cell to determine whether it is a failure of the fuel cell or a failure of the high voltage battery, and when it is the failure of the fuel cell, to determine a cause of the failure by calculating an insulation resistance variation; and a storage configured to store data and algorithms driven by the processor.

## Claims

### Claim 1

An insulation resistance detection apparatus comprising:
a processor configured to separate a fuel cell from a high voltage battery, by a main relay circuit, based on an insulation resistance value of a vehicle during driving of the vehicle, and to measure an insulation resistance value of the fuel cell with the fuel cell and high-voltage battery separated, by using an insulation resistance measurement device, to determine whether a failure of the fuel cell is present or a failure of the high voltage battery is present, and when the failure of the fuel cell is present, to determine a cause of the failure by calculating a variation of insulation resistance; and
a storage configured to store data and algorithms driven by the processor;
wherein the processor maintains an open circuit voltage (OCV) state by blocking a stack current of the fuel cell when the insulation resistance value of the vehicle is smaller than a predetermined reference value.

### Claim 2 (depends on 1)

The insulation resistance detection apparatus of claim 1, wherein the processor calculates an average value of insulation resistance values of the vehicle and stores the average insulation resistance value in the storage during starting off of the vehicle.

### Claim 3 (depends on 2)

The insulation resistance detection apparatus of claim 2, wherein the processor turns off a main relay connected between the fuel cell and the high voltage battery when the insulation resistance value of the vehicle is smaller than a predetermined reference value.

### Claim 4 (depends on 3)

The insulation resistance detection apparatus of claim 3, wherein the processor compares the insulation resistance value of the fuel cell with a predetermined reference value in a state in which the main relay is turned off.

### Claim 5 (depends on 4)

The insulation resistance detection apparatus of claim 4, wherein the processor determines that the failure due to insulation resistance of the high voltage battery exists when the insulation resistance value of the fuel cell is equal to or greater than the reference value.

### Claim 6 (depends on 4)

The insulation resistance detection apparatus of claim 4, wherein the processor, when the insulation resistance value of the fuel cell is smaller than the predetermined reference value,
calculates a difference value between the average insulation resistance value and the insulation resistance value of the fuel cell as the variation of insulation resistance.

### Claim 7 (depends on 6)

The insulation resistance detection apparatus of claim 6, wherein the processor compares the variation of insulation resistance and a predetermined variation reference value to determine that the a failure of insulation resistance due to an increase in ionic conductivity exists when the insulation resistance variation is smaller than the variation reference value, and to determine that the failure due to insulation breakdown of the fuel cell exists when the insulation resistance variation is equal to or greater than the variation reference value.

### Claim 8 (depends on 7)

The insulation resistance detection apparatus of claim 7, wherein the processor notifies replacement of an ion filter when it is determined that the failure of insulation resistance is due to the increase in ionic conductivity.

### Claim 9 (depends on 6)

The insulation resistance detection apparatus of claim 6, wherein the processor determines that the failure due to insulation breakdown of the fuel cell exists when the insulation resistance value rapidly changes, and determines that the failure of insulation resistance due to an increase in ionic conductivity exists when the insulation resistance value smoothly changes.

### Claim 10

A vehicle system comprising:
a fuel cell configured to supply power;
a high voltage battery configured to charge and discharge;
a main delay positioned between the fuel cell and the high voltage battery;
a first insulation resistance measurement device connected to an output terminal of the fuel cell to measure an insulation resistance value of the fuel cell;
a second insulation resistance measurement device connected to an output terminal of the high voltage battery to measure an insulation resistance value of the high voltage battery; and
an insulation resistance detection apparatus configured to separate a fuel cell from a high voltage battery based on an insulation resistance value of a vehicle during driving of the vehicle, and to determine whether a failure of the fuel cell is present or a failure of the high voltage battery is present, and when the failure of the fuel cell is present using the insulation resistance value measured when the fuel cell and high voltage battery are separated, to determine a cause of the failure by calculating a variation of insulation resistance;
wherein the insulation resistance detection apparatus turns off a main relay connected between the fuel cell and the high voltage battery when the insulation resistance value of the vehicle is smaller than a predetermined reference value, and controls the first insulation resistance measurement device to measure the insulation resistance value of the fuel cell.

### Claim 11 (depends on 10)

The vehicle system of claim 10, wherein the insulation resistance detection apparatus determines that the failure due to insulation resistance of the high voltage battery is present when the insulation resistance value of the fuel cell is equal to or greater than the reference value, and calculates the variation of insulation resistance when the insulation resistance value of the fuel cell is smaller than the reference value.

### Claim 12 (depends on 11)

The vehicle system of claim 11, wherein the insulation resistance detection apparatus calculate an average value of insulation resistance values of the vehicle and store the average insulation resistance value in the storage when starting off the vehicle, and calculates a difference value between the average insulation resistance value and the insulation resistance value of the fuel cell as the variation of insulation resistance.

### Claim 13

An insulation resistance detection method comprising:
separating, by a main relay circuit, a fuel cell from a high voltage battery based on an insulation resistance value of a vehicle during driving of the vehicle;
determining, by using an insulation resistance measurement device, whether a failure of the fuel cell is present or a failure of the high voltage battery is present by measuring the insulation resistance value of the fuel cell with the fuel cell and high-voltage battery separated; and
determining, by the insulation resistance measurement device, a cause of the failure by calculating a variation of insulation resistance when the failure of the fuel cell is present;
wherein the separating of the fuel cell and the high voltage battery includes:
maintaining an open circuit voltage (OCV) state by blocking a stack current of the fuel cell when the insulation resistance value of the vehicle is smaller than a predetermined reference value; and
turning off a main relay connected between the fuel cell and the high voltage battery.

### Claim 14 (depends on 13)

The insulation resistance detection method of claim 13, further comprising calculating an average value of insulation resistance values of the vehicle and store the average insulation resistance value in the storage when starting off the vehicle.

### Claim 15 (depends on 13)

The insulation resistance detection method of claim 13, wherein the determining of whether the failure of the fuel cell is present or the failure of the high voltage battery is present includes:
determining whether the insulation resistance value of the fuel cell is smaller than the reference value in a state where the main relay is turned off; and
determining that the a failure due to insulation resistance of the high voltage battery is present when the insulation resistance value of the fuel cell is equal to or greater than the reference value.

### Claim 16 (depends on 15)

The insulation resistance detection method of claim 15, wherein the determining of the cause of the failure includes, when the insulation resistance value of the fuel cell is smaller than the reference value, calculating a difference value between the average insulation resistance value and the insulation resistance value of the fuel cell as the variation of insulation resistance.

### Claim 17 (depends on 16)

The insulation resistance detection method of claim 16, wherein the determining of the cause of the failure further includes:
comparing the variation of insulation resistance and a predetermined variation reference value;
determining that the a failure of insulation resistance due to an increase in ionic conductivity is present when the insulation resistance variation is smaller than the variation reference value; and
determining that the failure due to insulation breakdown of the fuel cell is present when the insulation resistance variation is equal to or greater than the variation reference value.