# US 12,120,800 B2 · Induction heating apparatus and method for controlling induction heating apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,120,800 B2 - Document ID: US12120800B2 - Status: Granted - Kind: B2 - Application number: 17/271,112 - Filed: 2019-08-30 - Published: 2021-10-21 - Granted: 2024-10-15 - Earliest claimed: 2018-08-30 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Wongyu Park; Gwang Rok Kim; Bada Yoon; John Kang - Web page: https://patentgrep.com/patent/US12120800B2 ## CPC - H02M 7/4815: {Resonant converters (H02M7/4811 and H02M7/4826 take precedence)} - H05B 6/065: {using coordinated control of multiple induction coils} - H02M 1/008: {Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators} - H02M 3/158: including plural semiconductor devices as final control devices for a single load - H05B 6/04: Sources of current - H05B 6/1272: {with more than one coil or coil segment per heating zone} - H02M 5/458: using semiconductor devices only - Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A method for controlling an induction heating device according to an embodiment of the present disclosure includes driving a first working coil at a first target frequency, receiving a driving command for a second working coil, stopping the driving of the first working coil and driving the second working coil at a preset first adjustment frequency, and determining a second target frequency of the second working coil corresponding to the driving command for the second working coil. ## Claims ### Claim 1 A method for controlling an induction heating device, the method comprising: driving a first working coil at a first target frequency; receiving a driving command for a second working coil; stopping the driving of the first working coil and driving the second working coil at a preset first adjustment frequency; and determining a second target frequency of the second working coil corresponding to the driving command for the second working coil. ### Claim 2 (depends on 1) The method of claim 1, wherein the determining of the second target frequency of the second working coil includes: reducing a driving frequency of the second working coil; and determining a driving frequency when an output of the second working coil corresponds to a requested output corresponding to the driving command for the second working coil as the second target frequency. ### Claim 3 (depends on 1) The method of claim 1, further comprising: determining a first final driving frequency of the first working coil and a second final driving frequency of the second working coil based on the first target frequency and the second target frequency, respectively; and driving the first working coil at the first final driving frequency and driving the second working coil at the second final driving frequency. ### Claim 4 (depends on 3) The method of claim 3, wherein the determining of the first final driving frequency of the first working coil and the second final driving frequency of the second working coil includes: calculating a difference value between the first target frequency and the second target frequency; and determining the first final driving frequency and the second final driving frequency according to a comparison result between the difference value and a preset reference value. ### Claim 5 (depends on 4) The method of claim 4, wherein, when the difference value is less than a first reference value, the first final driving frequency and the second final driving frequency are set to be equal to each other. ### Claim 6 (depends on 4) The method of claim 4, wherein, when the difference value is less than the first reference value, the first final driving frequency and the second final driving frequency are set as any one among the first target frequency and the second target frequency. ### Claim 7 (depends on 4) The method of claim 4, wherein, when the difference value is equal to or greater than a first reference value and less than a second reference value, a difference between the first final driving frequency and the second final driving frequency is set to be equal to or greater than a preset noise avoidance setting value. ### Claim 8 (depends on 4) The method of claim 4, wherein, when the difference value is equal to or greater than a first reference value and less than a second reference value, a value obtained by increasing a larger value among the first target frequency and the second target frequency by the preset noise avoidance setting value or more and a smaller value among the first target frequency and the second target frequency are set as the first final driving frequency and the second final driving frequency, respectively. ### Claim 9 (depends on 4) The method of claim 4, wherein, when the difference value is equal to or greater than a second reference value, the first final driving frequency is set as the first target frequency, and the second final driving frequency is set as the second target frequency. ### Claim 10 An induction heating device comprising: a first working coil disposed to correspond to a first heating area; a second working coil disposed to correspond to a second heating area; and a control unit configured to adjust driving frequencies of the first working coil and the second working coil according to a driving command input by a user, wherein the control unit drives the first working coil at a first target frequency, receives a driving command for the second working coil, stops driving of the first working coil and drives the second working coil at a preset first adjustment frequency, and determines a second target frequency of the second working coil corresponding to the driving command for the second working coil. ### Claim 11 (depends on 10) The induction heating device of claim 10, wherein the control unit reduces a driving frequency of the second working coil and determines a driving frequency when an output of the second working coil corresponds to a requested output corresponding to the driving command for the second working coil as the second target frequency. ### Claim 12 (depends on 10) The induction heating device of claim 10, wherein the control unit determines a first final driving frequency of the first working coil and a second final driving frequency of the second working coil based on the first target frequency and the second target frequency, respectively, and drives the first working coil at the first final driving frequency and drives the second working coil at the second final driving frequency. ### Claim 13 (depends on 12) The induction heating device of claim 12, wherein the control unit calculates a difference value between the first target frequency and the second target frequency and determines the first final driving frequency and the second final driving frequency according to a comparison result between the difference value and a preset reference value. ### Claim 14 (depends on 13) The induction heating device of claim 13, wherein, when the difference value is less than a first reference value, the first final driving frequency and the second final driving frequency are set to be equal to each other. ### Claim 15 (depends on 13) The induction heating device of claim 13, wherein, when the difference value is less than a first reference value, the first final driving frequency and the second final driving frequency are set as any one among the first target frequency and the second target frequency. ### Claim 16 (depends on 13) The induction heating device of claim 13, wherein, when the difference value is equal to or greater than a first reference value and less than a second reference value, a difference between the first final driving frequency and the second final driving frequency is set to be equal to or greater than a preset noise avoidance setting value. ### Claim 17 (depends on 13) The induction heating device of claim 13, wherein, when the difference value is equal to or greater than a first reference value and less than a second reference value, a value obtained by increasing a larger value among the first target frequency and the second target frequency by the preset noise avoidance setting value or more and a smaller value among the first target frequency and the second target frequency are set as the first final driving frequency and the second final driving frequency, respectively. ### Claim 18 (depends on 13) The induction heating device of claim 13, wherein, when the difference value is equal to or greater than a second reference value, the first final driving frequency is set as the first target frequency, and the second final driving frequency is set as the second target frequency.