# US 7,613,018 B2 · Apparatus and method for supplying DC power source > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,613,018 B2 - Document ID: US7613018B2 - Status: Granted - Kind: B2 - Application number: 11/532,550 - Filed: 2006-09-18 - Published: 2007-09-20 - Granted: 2009-11-03 - Earliest claimed: 2006-03-14 - Assignees: LG Electronics Inc. - Inventors: Sun-Kyoung Lim; Dai-Hyun Kim; Hag-Wone Kim - Web page: https://patentgrep.com/patent/US7613018B2 ## CPC - H02M 1/4208: {Arrangements for improving power factor of AC input} - H02M 5/4585: {having a rectifier with controlled elements} - H02M 1/0085: {Partially controlled bridges} - 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) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract An apparatus and method for supplying a direct current power source which is capable of compensating a power factor of an input power source by detecting an input current amount according to load changes, the apparatus comprising an input current detecting unit for detecting an input current amount to determine a load size, a power factor control unit for outputting a power factor control signal and an input current amount control signal according to the determined load size, an input current refluxing unit for refluxing the input current by cutting off an input power source based upon the input current amount control signal, an active filter for reducing a harmonic of the input current, rectifying an input alternating current (AC) voltage and boosting a smoothing voltage, a power factor compensating unit for supplying charged energy to the load based upon the power factor control signal, a smoothing unit for smoothing the rectified input AC voltage into a direct current (DC) voltage, and an inverter for converting the smoothed DC voltage into an AC voltage, whereby a power factor compensation (PFC) spec can be satisfied although the load is increased and fabricating cost can be decreased by allowing the use of a reactor with a low capacity. ## Claims ### Claim 1 An apparatus for supplying a direct current power source, comprising: an input current detector that detects an input current amount to determine a load size; a power factor controller that outputs a power factor control signal and an input current amount control signal according to the determined load size; an input current refluxer that refluxes the input current by cutting off an input power source based upon the input current amount control signal; an active filter that reduces a harmonic of the input current, rectifies an input alternating current (AC) voltage and boosts a smoothing voltage; a power factor compensator that charges energy from a commercial power source and supplies the charged energy to the load based upon the power factor control signal; a smoother that smooths the rectified AC voltage into a direct current (DC) voltage; and an inverter that converts the smoothed DC voltage into an AC voltage. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the input current detector further includes a memory that stores a data table indicating a relation between the input current amount and the load size corresponding thereto. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the input current detector determines the load size by detecting a DC-link current. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the power factor controller comprises: a synchronous signal generator that detects a zero-crossing time point of the input power source and generates a synchronous signal based upon the detected zero-crossing time point; and an on/off controller that outputs an input current amount control signal to control a first switch and a power factor control signal to control a second switch. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the input current amount control signal and the power factor control signal are generated by being synchronized with the synchronous signal. ### Claim 6 (depends on 4) The apparatus of claim 4, wherein the on/off controller turns off the second switch and outputs the input current amount control signal to control the first switch when the determined load size is smaller than a reference load size, and outputs both the input current amount control signal to control the first switch and the power factor control signal to control the second switch when the determined load size is equal to or greater than the reference load size. ### Claim 7 (depends on 4) The apparatus of claim 4, wherein the on/off controller determines a pulse width modulation (PWM) ratio of each of the input current amount control signal and the power factor control signal in proportion to the load size. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the input current refluxer comprises: a diode bridge circuit that forms a reflux path of the input current toward the input power source; and a first switch that turns on/off the reflux path of the input current based upon the input current amount control signal. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the active filter comprises: a small reactor that reduces a harmonic and boosts a smoothing voltage; and a diode bridge circuit that rectifies an input alternating current (AC) voltage. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the power factor compensator charges energy from the input power source and discharges energy to the load. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein the power factor compensator comprises: a second switch that turns on/off a path for charging or discharging energy based upon the power factor control signal; and a capacitor that charges energy from the input power source and discharges energy to the smoothing unit. ### Claim 12 A method for supplying a direct current power source, comprising: detecting an input current amount to determine a load size; outputting a power factor control signal and an input current amount control signal according to the determined load size; refluxing the input current by cutting off an input power source based upon the input current amount control signal; reducing a harmonic of the input current, rectifying the input AC voltage and boosting a smoothing voltage; charging energy from a commercial power source and supplying the charged energy to the load based upon the power factor control signal; smoothing the rectified input AC voltage into a DC voltage; and converting the smoothed DC voltage into an AC voltage. ### Claim 13 (depends on 12) The method of claim 12, wherein determining the load size comprises: using a data table stored in a memory, the data table indicating a relation between the input current amount and the load size corresponding thereto. ### Claim 14 (depends on 12) The method of claim 12, wherein determining the load size comprises determining the load size by detecting a DC-link current. ### Claim 15 (depends on 12) The method of claim 12, wherein outputting the power factor control signal and the input current amount control signal comprises: detecting a zero-crossing time point of the input power source and generating a synchronous signal based upon the detected zero-crossing time point; and outputting the input current amount control signal to control the first switch and the power factor control signal to control the second switch based upon the determined load size. ### Claim 16 (depends on 15) The method of claim 15, wherein outputting the input current amount control signal and the power factor control signal comprises: generating the input current amount control signal and the power factor control signal which are synchronized with the synchronous signal. ### Claim 17 (depends on 15) The method of claim 15, wherein outputting the input current amount control signal and the power factor control signal comprises: varying a switching time of each of the first switch and the second switch based upon the load size. ### Claim 18 (depends on 15) The method of claim 15, wherein outputting the input current amount control signal and the power factor control signal comprises: turning off the second switch and outputting the input current amount control signal to control the first switch, when the determined load size is smaller than a reference load size; and outputting both the input current amount control signal to control the first switch and the power factor control signal to control the second switch, when the determined load size is equal to or greater than the reference load size. ### Claim 19 (depends on 15) The method of claim 15, wherein outputting the input current amount control signal and the power factor control signal comprises: determining a pulse width modulation (PWM) ratio of each of the input current amount control signal and the power factor control signal in proportion to the determined load size. ### Claim 20 (depends on 12) The method of claim 12, where refluxing the input current comprises: forming a reflux path of the input current toward the input power source; and cutting off the reflux path of the input current based upon the input current amount control signal. ### Claim 21 (depends on 12) The method of claim 12, wherein supplying energy to the load comprises: cutting off the second switch based upon the power factor control signal to accordingly charge energy in the capacitor from the input power source and discharge energy to the load.