# US 11,906,591 B2 · Insulation resistance measurement apparatus and method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,591 B2 - Document ID: US11906591B2 - Status: Granted - Kind: B2 - Application number: 17/293,589 - Filed: 2019-12-18 - Published: 2022-01-06 - Granted: 2024-02-20 - Earliest claimed: 2019-01-03 - Assignees: LG Energy Solution, Ltd. - Applicants: LG Energy Solution, Ltd. - Inventors: Sung Gun Lee - Web page: https://patentgrep.com/patent/US11906591B2 ## CPC - G01R 27/025: {Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters} - G01R 31/3842: combining voltage and current measurements - G01R 27/14: Measuring resistance by measuring current or voltage obtained from a reference source (G01R27/16, G01R27/20, G01R27/22 take precedence) - G01R 27/18: Measuring resistance to earth {, i.e. line to ground} - G01R 31/36: Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] - G01R 31/3646: {for indicating electrical conditions or variables, e.g. visual or audible indicators} - G01R 31/3648: {comprising digital calculation means, e.g. for performing an algorithm} - G01R 31/52: Testing for short-circuits, leakage current or ground faults - H01M 10/425: {Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00)} - 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 2010/4271: {Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing} - Y02E 60/10: Energy storage using batteries - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - 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 measurement apparatus includes a first resistance unit having one end connected to an anode of a battery and the other end connected ground, and variably having a first resistance value or a second resistance value greater than the first resistance value; a second resistance unit having one end connected to a cathode of the battery and the other end connected to ground, and variably having a third resistance value or a fourth resistance value greater than the third resistance value; a voltage measurement unit configured to measure a voltage across the first or second resistance unit; and an insulation resistance calculation unit configured to calculate a first insulation resistance value between the anode of the battery and ground and a second insulation resistance value between the cathode of the battery and ground by using the first to fourth resistance values and the measured voltage. ## Claims ### Claim 1 An insulation resistance measurement apparatus comprising: a first resistance unit having a first end connected to a positive side of a battery and a second end connected to a ground, wherein the first resistance unit is variably controllable between having a first resistance value or a second resistance value greater than the first resistance value; a second resistance unit having a first end connected to a negative side of the battery and a second end connected to the ground, wherein the second resistance unit is variably controllable between having a third resistance value or a fourth resistance value greater than the third resistance value; a voltage measurement unit configured to measure a voltage across the first resistance unit and a voltage across the second resistance unit; and an insulation resistance calculation unit configured to calculate a first insulation resistance value between the positive side of the battery and the ground and a second insulation resistance value between the negative side of the battery and the ground based on the first resistance value, the second resistance value, the third resistance value, the fourth resistance value and the voltage measured by the voltage measurement unit wherein the insulation resistance calculation unit has a first insulation resistance measurement mode and a second insulation resistance measurement mode, wherein the first insulation resistance measurement mode has a lower error rate than the second insulation resistance measurement mode in a first measurement range, and wherein the second insulation resistance measurement mode has a lower error rate than the first insulation resistance measurement mode in a second measurement range. ### Claim 2 (depends on 1) The insulation resistance measurement apparatus of claim 1, further comprising a voltage distribution unit connected in parallel with the first resistance unit or the second resistance unit, wherein the voltage distribution unit includes a plurality of resistors connected in series, wherein the voltage measured by the voltage measurement unit is a voltage measured across some of the plurality of resistors of the voltage distribution unit. ### Claim 3 (depends on 2) The insulation resistance measurement apparatus of claim 2, wherein the insulation resistance calculation unit is configured to: calculate the first and second insulation resistance values based on the first resistance value and the third resistance value in the first insulation resistance measurement mode, and calculate the first and second insulation resistance values based on the second resistance value and the fourth resistance value in the second insulation resistance measurement mode. ### Claim 4 (depends on 3) The insulation resistance measurement apparatus of claim 3, wherein, for the first insulation resistance value, the insulation resistance calculation unit is configured to: determine whether the first insulation resistance value is within the first or second measurement range; and calculate a first actual insulation resistance value in whichever measurement mode has the lower error rate in the determined first or second measurement range that the first insulation resistance value is within, and for the second insulation resistance value, the insulation resistance calculation unit is configured to: determine whether the second insulation resistance value is within the first or second measurement range; and calculate a second actual insulation resistance value in whichever measurement mode has the lower error rate in the determined first or second measurement range that the second insulation resistance value is within. ### Claim 5 (depends on 3) The insulation resistance measurement apparatus of claim 3, wherein the first resistance unit includes a first resistance value unit that is ON/OFF controlled by a first switch and a second resistance value unit that is ON/OFF controlled by a second switch, wherein the first and second resistance value units are connected in parallel between the positive side of the battery and the ground, wherein the second resistance unit includes a third resistance value unit that is ON/OFF controlled by a third switch and a fourth resistance value unit that is ON/OFF controlled by a fourth switch, wherein the third and fourth resistance value units are connected in parallel between the negative side of the battery and the ground. ### Claim 6 (depends on 5) The insulation resistance measurement apparatus of claim 5, when the first switch or the second switch of the first resistance unit is ON, the insulation resistance calculation unit controls the third switch and the fourth switch of the second resistance unit to be OFF. ### Claim 7 (depends on 5) The insulation resistance measurement apparatus of claim 5, when the third switch or the fourth switch of the second resistance unit is ON, the insulation resistance calculation unit controls the first switch and the second switch of the first resistance unit to be OFF. ### Claim 8 (depends on 5) The insulation resistance measurement apparatus of claim 5, wherein, in the first insulation resistance measurement mode, the insulation resistance calculation unit is configured to calculate the first and second insulation resistance values based on the voltage measured across some of the plurality resistors of the voltage distribution unit when the first switch is ON and the second, third and fourth switches are OFF and the voltage measured across some of the plurality of resistors of the voltage distribution unit when the third switch is ON and the first, second and fourth switches are OFF. ### Claim 9 (depends on 5) The insulation resistance measurement apparatus of claim 5, wherein in the second insulation resistance measurement mode, the insulation resistance calculation unit is configured to calculate the first and second insulation resistance values based on the voltage measured across some of the plurality of resistors of the voltage distribution unit when the second switch is ON and the first, third, and fourth switches are OFF and the voltage measured across some of the plurality of resistors of the voltage distribution unit when the fourth switch is ON and the first, second and third switches are OFF. ### Claim 10 (depends on 1) The insulation resistance measurement apparatus of claim 1, wherein the first, second, third and fourth resistance values vary according to the battery or according to a device in which the battery is mounted. ### Claim 11 (depends on 2) The insulation resistance measurement apparatus of claim 2, wherein the voltage distribution unit further comprises a switch connected in series with the plurality of resistors, and wherein the switch is configured to be ON/OFF controlled. ### Claim 12 (depends on 1) The insulation resistance measurement apparatus of claim 1, wherein the battery is a battery rack, and wherein the ground is a chassis of the battery rack. ### Claim 13 (depends on 3) The insulation resistance measurement apparatus of claim 3, wherein the first resistance unit includes a first variable resistance unit that is changeable between the first resistance value and the second resistance value based on ON/OFF control by a first switch, wherein the first variable resistance unit is between the positive side of the battery and the ground, and wherein the second resistance unit includes a second variable resistance unit that is changeable between the third resistance value and the fourth resistance value based on ON/OFF control by a second switch, wherein the second variable resistance unit is between the negative side of the battery and the ground. ### Claim 14 An insulation resistance measurement method comprising: calculating, by a controller, a first insulation resistance value of a first resistance unit having a first variable resistance and positioned between a positive side of a battery and a ground and a second insulation resistance value of a second resistance unit having a second variable resistance and positioned between a negative side of the battery and the ground in each of a first insulation resistance measurement mode and a second insulation resistance measurement mode, wherein the first insulation resistance measurement mode has a lower error rate than the second insulation resistance measurement mode in a first measurement range, and wherein the second insulation resistance measurement mode has a lower error rate than the first insulation resistance measurement mode in a second measurement range; determining, by the controller, which of the respective measurement ranges corresponds to each of the first and second insulation resistance values; and determining, by the controller, an actual insulation resistance value using the respective insulation resistance measurement mode for which the insulation resistance measurement error rate within the determined measurement range is lowest. ### Claim 15 (depends on 14) The insulation resistance measurement method of claim 14, further comprising changing between the first insulation resistance measurement mode and the second insulation resistance measurement mode by changing a resistance value of a first resistance unit having a first end connected to the positive side of the battery and a second end connected to the ground, and a resistance value of a second resistance unit having a first end connected to the negative side of the battery and a second end connected to the ground.