# US 2018/0323700 A1 · Power convertor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323700 A1 - Document ID: US20180323700A1 - Status: Published application - Kind: A1 - Application number: 15/769,376 - Filed: 2017-01-26 - Published: 2018-11-08 - Earliest claimed: 2016-01-29 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Hiroto MIZUTANI; Ryota KONDO; Takaaki TAKAHARA - Web page: https://patentgrep.com/patent/US20180323700A1 ## CPC - H02M 1/4258: {using a single converter stage both for correction of AC input power factor and generation of a regulated and galvanically isolated DC output voltage (H02M1/4241 takes precedence)} - H02M 1/088: for the simultaneous control of series or parallel connected semiconductor devices - H02M 3/33553: {with galvanic isolation between input and output of both the power stage and the feedback loop} - H02M 3/33576: {having at least one active switching element at the secondary side of an isolation transformer} - H02M 3/3376: {with automatic control of output voltage or current} - H02M 1/0009: {Devices or circuits for detecting current in a converter} - H02M 7/06: using discharge tubes without control electrode or semiconductor devices without control electrode - H02M 7/53871: {with automatic control of output voltage or current} - 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 This power conversion device includes: a rectification circuit; an inverter circuit having a full-bridge configuration, and having a DC capacitor, and first and second legs each of which has two switching elements connected in series to each other; a transformer; and a control circuit for controlling operation of the inverter circuit, wherein the control circuit controls an ON period for the first leg, thereby controlling increase/decrease in current flowing through a first rectification circuit from an AC input, and controls an ON period for the second leg and a phase shift amount between the ON period for the first leg and the ON period for the second leg, thereby controlling voltage of the DC capacitor to be constant. Thus, it becomes possible to achieve high-power-factor control and output power control at the same time by a single stage of full-bridge inverter circuit. ## Claims ### Claim at position 1 1-14. (canceled) ### Claim 15 A power conversion device comprising: a first rectification circuit which rectifies AC power inputted from an AC power supply; an inverter circuit having a first leg, a second leg, and a DC capacitor connected in parallel to each other, the first leg having a first switching element and a second switching element connected in series to each other, a positive-side DC terminal of the first rectification circuit being connected to a first AC end which is a connection point between the first switching element and the second switching element, the second leg having a third switching element and a fourth switching element to which diodes are respectively connected in antiparallel, the third switching element and the fourth switching element being connected in series to each other, the inverter circuit having a negative-side DC bus connected to a negative-side DC terminal of the first rectification circuit; a transformer having a primary winding and a secondary winding, one end of the primary winding being connected to the first AC end of the inverter circuit, and another end of the primary winding being connected to a second AC end which is a connection point between the third switching element and the fourth switching element; a second rectification circuit having one end connected to the secondary winding of the transformer and another end connected to a DC load via a smoothing capacitor, the second rectification circuit rectifying AC power inputted from the transformer, and outputting the resultant power to the DC load; a control circuit which controls operation of the inverter circuit; a voltage detector which detects DC voltage of the DC capacitor; and a current detector which detects current outputted from the first rectification circuit, wherein the control circuit determines an ON period for the first leg on the basis of a detection result of the current detector, and controls the first switching element and the second switching element on the basis of the determined ON period for the first leg, thereby controlling current outputted from the first rectification circuit, and on the basis of a detection result of the voltage detector and the determined ON period for the first leg, the control circuit controls an ON period for the second leg and a phase shift amount between the ON period for the first leg and the ON period for the second leg, thereby controlling voltage of the DC capacitor to be constant. ### Claim 16 (depends on 15) The power conversion device according to claim 15, wherein the control circuit uses: a first operation mode in which the first switching element and the fourth switching element are turned on; a second operation mode in which the first switching element and the third switching element are turned on; a third operation mode in which the second switching element and the third switching element are turned on; and a fourth operation mode in which the second switching element and the fourth switching element are turned on, and the control circuit controls respective periods of the first to fourth operation modes in this order, thereby controlling the inverter circuit. ### Claim 17 (depends on 15) The power conversion device according to claim 15, wherein the control circuit uses: a first operation mode in which the first switching element and the fourth switching element are turned on; a second operation mode in which the first switching element and the third switching element are turned on; a third operation mode in which the second switching element and the third switching element are turned on; and a fourth operation mode in which the second switching element and the fourth switching element are turned on, and the control circuit controls the inverter circuit, using a first operation sub mode in which respective periods of the first to fourth operation modes are controlled in this order, and a second operation sub mode in which the respective periods are controlled in order of the fourth operation mode, the third operation mode, the fourth operation mode, and then the first operation mode. ### Claim 18 (depends on 15) The power conversion device according to claim 15, wherein the control circuit controls the ON period for the first leg so that current outputted from the first rectification circuit becomes predetermined target sinewave current, and the control circuit controls the phase shift amount and the ON period for the second leg so that voltage of the DC capacitor becomes target voltage which is higher than peak voltage of AC voltage inputted from the AC power supply. ### Claim 19 (depends on 16) The power conversion device according to claim 16, wherein the control circuit controls the ON period for the first leg so that current outputted from the first rectification circuit becomes predetermined target sinewave current, and the control circuit controls the phase shift amount and the ON period for the second leg so that voltage of the DC capacitor becomes target voltage which is higher than peak voltage of AC voltage inputted from the AC power supply. ### Claim 20 (depends on 17) The power conversion device according to claim 17, wherein the control circuit controls the ON period for the first leg so that current outputted from the first rectification circuit becomes predetermined target sinewave current, and the control circuit controls the phase shift amount and the ON period for the second leg so that voltage of the DC capacitor becomes target voltage which is higher than peak voltage of AC voltage inputted from the AC power supply. ### Claim 21 (depends on 18) The power conversion device according to claim 18, wherein the control circuit controls the phase shift amount between the ON period for the first leg and the ON period for the second leg, using, as an upper limit, the smaller one of two ON periods of the first switching element and the second switching element. ### Claim 22 (depends on 19) The power conversion device according to claim 19, wherein the control circuit controls the phase shift amount between the ON period for the first leg and the ON period for the second leg, using, as an upper limit, the smaller one of two ON periods of the first switching element and the second switching element. ### Claim 23 (depends on 20) The power conversion device according to claim 20, wherein the control circuit controls the phase shift amount between the ON period for the first leg and the ON period for the second leg, using, as an upper limit, the smaller one of two ON periods of the first switching element and the second switching element. ### Claim 24 (depends on 18) The power conversion device according to claim 18, wherein the control circuit synchronizes timings of shifting phases for the third switching element and the fourth switching element, with each other. ### Claim 25 (depends on 19) The power conversion device according to claim 19, wherein the control circuit synchronizes timings of shifting phases for the third switching element and the fourth switching element, with each other. ### Claim 26 (depends on 18) The power conversion device according to claim 18, wherein the control circuit controls the ON periods for the first leg and second leg and the phase shift amount for the second leg so that a period during which an ON period of the first switching element and an ON period of the fourth switching element which is diagonal thereto overlap each other, and a period during which an ON period of the second switching element and an ON period of the third switching element which is diagonal thereto overlap each other, become equal to each other. ### Claim 27 (depends on 18) The power conversion device according to claim 18, wherein the control circuit controls the first switching element and the second switching element so that their ON and OFF states are inverted relative to each other, and in an initial state in which the phase shift amount is zero, the control circuit controls a gate pulse width and a phase for the third switching element to be equal to those for the first switching element, and controls a gate pulse width and a phase for the fourth switching element to be equal to those for the second switching element. ### Claim 28 (depends on 18) The power conversion device according to claim 18, wherein the control circuit controls the first switching element and the second switching element so that their ON and OFF states are inverted relative to each other, and in an initial state in which the phase shift amount is zero, the control circuit controls a gate pulse width and a phase for the third switching element to be equal to those for the second switching element, and controls a gate pulse width and a phase for the fourth switching element to be equal to those for the first switching element. ### Claim 29 (depends on 27) The power conversion device according to claim 27, wherein the control circuit uses saw-tooth waves as carrier waves for the first leg and the second leg, and the control circuit performs control such that, as the phase shift amount increases, a phase of rising of a gate pulse for the third switching element is shifted relative to a phase of rising of a gate pulse for the first switching element while an ON period of the third switching element is made equal to an ON period of the first switching element, and a phase of rising of a gate pulse for the fourth switching element is shifted relative to a phase of rising of a gate pulse for the second switching element while an ON period of the fourth switching element is made equal to an ON period of the second switching element. ### Claim 30 (depends on 27) The power conversion device according to claim 27, wherein the control circuit uses triangular waves as carrier waves for the first leg and the second leg, and the control circuit performs control such that, as the phase shift amount increases, a phase of rising of a gate pulse for the third switching element is shifted relative to a phase of rising of a gate pulse for the first switching element while an ON period of the third switching element is made equal to an ON period of the first switching element, and a phase of rising of a gate pulse for the fourth switching element is shifted relative to a phase of rising of a gate pulse for the second switching element while an ON period of the fourth switching element is made equal to an ON period of the second switching element. ### Claim 31 (depends on 28) The power conversion device according to claim 28, wherein the control circuit uses saw-tooth waves as carrier waves for the first leg and the second leg, and the control circuit performs control such that, as the phase shift amount increases, a phase of rising of a gate pulse for the third switching element is shifted relative to a phase of rising of a gate pulse for the second switching element while an ON period of the third switching element is made equal to an ON period of the first switching element, and a phase of rising of a gate pulse for the fourth switching element is shifted relative to a phase of rising of a gate pulse for the first switching element while an ON period of the fourth switching element is made equal to an ON period of the second switching element. ### Claim 32 (depends on 28) The power conversion device according to claim 28, wherein the control circuit uses triangular waves as carrier waves for the first leg and the second leg, and the control circuit performs control such that, as the phase shift amount increases, a phase of rising of a gate pulse for the third switching element is shifted relative to a phase of rising of a gate pulse for the second switching element while an ON period of the third switching element is made equal to an ON period of the first switching element, and a phase of rising of a gate pulse for the fourth switching element is shifted relative to a phase of rising of a gate pulse for the first switching element while an ON period of the fourth switching element is made equal to an ON period of the second switching element. ### Claim 33 (depends on 26) The power conversion device according to claim 26, further comprising a smoothing reactor connected to a DC terminal of the second rectification circuit, wherein the control circuit controls the ON period for the second leg on the basis of a voltage value of the DC capacitor, a voltage value of the smoothing capacitor, a current value of the smoothing reactor, a calculated value of a duty cycle for the first switching element, a duty cycle for the second switching element, and a calculated value of the phase shift amount for the second leg. ### Claim 34 (depends on 26) The power conversion device according to claim 26, further comprising a smoothing reactor connected to a DC terminal of the second rectification circuit, wherein the control circuit controls the ON period for the first leg on the basis of a voltage value of the DC capacitor, a voltage value of the smoothing capacitor, a current value of the smoothing reactor, a calculated value of a duty cycle for the first switching element, a duty cycle for the second switching element, and a calculated value of the phase shift amount for the second leg.