US 12,308,737 B2
Power transforming apparatus and air conditioner including the same
Phillsik Gong, Seoul (KR); Songhee Yang, Seoul (KR); Jeongeon Oh, Seoul (KR); and Sanghyeon Kim, Seoul (KR)
Assigned to LG Electronics Inc., Seoul (KR)
Filed by LG Electronics Inc., Seoul (KR)
Filed on Sep. 26, 2022, as Appl. No. 17/952,832.
Claims priority of application No. 10-2021-0157864 (KR), filed on Nov. 16, 2021.
Prior Publication US 2023/0155487 A1, May 18, 2023
Int. Cl. H02M 1/42 (2007.01); F04B 35/04 (2006.01); F04B 49/06 (2006.01); H02M 1/00 (2007.01); H02M 1/08 (2006.01)
CPC H02M 1/4258 (2013.01) [F04B 35/04 (2013.01); F04B 49/06 (2013.01); H02M 1/0009 (2021.05); H02M 1/083 (2013.01); F04B 2203/0201 (2013.01); F04B 2203/0208 (2013.01); F04B 2203/0209 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A power transforming apparatus for driving an inverter to drive a motor, the power transforming apparatus comprising:
a rectifier configured to rectify an input AC voltage;
a power factor improving unit configured to perform a power factor correction (PFC) operation that improves a power factor on a rectified voltage output from the rectifier, the power factor improving unit comprising a plurality of converter channels;
a DC link capacitor configured to store an output voltage of the power factor improving unit;
a current sensor disposed between the rectifier and the power factor improving unit; and
a controller configured to (i) based on an input power and a speed of the motor calculated using the current sensor when the inverter is driven, determine a number of target converter channels to perform a PFC operation among the plurality of converter channels, and (ii) perform the PFC operation while changing the target converter channels corresponding to the determined number of converter channels at a time satisfying a preset condition,
wherein the power factor improving unit comprises a first converter channel, a second converter channel, and a third converter channel, wherein each converter channel is coupled to a reactor, and the reactor is disposed between a switching device of each converter channel and a diode,
wherein the controller is configured to (i) based on the calculated input power and the speed of the motor, determine whether to start the PFC operation, and (ii) detect a zero-crossing of a current flowing through the reactor in response to the PFC operation of target converter channels corresponding to a predetermined sequence, and
wherein the controller is configured to (i) based on the PFC operation being started, perform an initial switching operation with at least one converter channel selected using a random function, and (ii) based on the zero-crossing being detected, perform a switching operation by changing a target converter channel according to a switching sequence determined based on the selected at least one converter channel.