US 12,295,085 B2
Induction heating device with improved control algorithm
Seungbok Ok, Seoul (KR); Byeong Wook Park, Seoul (KR); and Jae-Woo Lee, Seoul (KR)
Assigned to LG Electronics Inc., Seoul (KR)
Appl. No. 16/766,595
Filed by LG Electronics Inc., Seoul (KR)
PCT Filed Nov. 28, 2018, PCT No. PCT/KR2018/014881
§ 371(c)(1), (2) Date May 22, 2020,
PCT Pub. No. WO2019/135492, PCT Pub. Date Jul. 11, 2019.
Claims priority of application No. 10-2018-0002326 (KR), filed on Jan. 8, 2018.
Prior Publication US 2021/0127459 A1, Apr. 29, 2021
Int. Cl. H05B 6/06 (2006.01); H05B 6/12 (2006.01)
CPC H05B 6/065 (2013.01) [H05B 6/1272 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An induction heating device, comprising:
a working coil group comprising a first working coil and a second working coil that are electrically connected in parallel to each other;
an inverter configured to perform a switching operation to thereby supply a resonance current to at least one of the first working coil or the second working coil;
a power supply configured to output alternating current (AC) power;
a rectifier configured to convert the AC power output from the power supply into direct current (DC) power and to supply the DC power to the inverter;
a first semiconductor switch electrically connected to the first working coil and a ground terminal, the first semiconductor switch being configured to turn on and turn off the first working coil;
a second semiconductor switch electrically connected to the second working coil and the ground terminal, the second semiconductor switch being configured to turn on and turn off the second working coil;
an auxiliary power supply configured to supply power to the first and second semiconductor switches; and
a controller configured to control operation of each of the inverter, the first semiconductor switch, and the second semiconductor switch,
wherein the inverter comprises at least two switching elements that are configured to be alternately turned on and turned off by switching signals received from the controller to thereby convert the DC power into the resonance current, and
wherein the controller is configured to:
turn off the at least two switching elements of the inverter at a first time point at which an input voltage of the power supply becomes zero while keeping at least one of the first semiconductor switch or the second semiconductor switch turned on, the input voltage of the power supply being an AC voltage corresponding to the AC power output from the power supply, and
turn off at least one of the first semiconductor switch or the second semiconductor switch at a second time point at which the input voltage of the power supply becomes zero directly after the first time point while keeping the at least two switching elements of the inverter turned off.