# US 12,184,203 B2 · Electric-power conversion apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,203 B2 - Document ID: US12184203B2 - Status: Granted - Kind: B2 - Application number: 18/160,736 - Filed: 2023-01-27 - Published: 2023-09-07 - Granted: 2024-12-31 - Earliest claimed: 2022-03-04 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Tomoko Konda - Web page: https://patentgrep.com/patent/US12184203B2 ## CPC - H02M 7/5387: in a bridge configuration - H02M 1/0009: {Devices or circuits for detecting current in a converter} - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 1/385: {with means for correcting output voltage deviations introduced by the dead time} - H02P 27/08: with pulse width modulation - 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) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract There is provided an electric-power conversion apparatus in which a dead time can be set, while in an electric-power converter in which an AC current flows in a series circuit of switching devices, there is considered the effect of an error between a current value obtained for setting a dead time and an actual current value at a time of setting the dead time. An electric-power conversion apparatus, for a series circuit of each set, obtains a value of a current flowing in the series circuit is obtained; for an obtained current value, corrects a current error caused by a phase shift between a value of an actual current at a time when the dead time is set and the obtained current value; and set the dead time based on the corrected current value. ## Claims ### Claim 1 An electric-power conversion apparatus comprising: an electric-power converter that performs conversion between DC electric power and AC electric power and is provided with two or more sets of series circuits in each of which a higher-potential-side switching device connected with a higher-potential-side DC electric wire where the DC electric power flows and a lower-potential-side switching device connected with a lower-potential-side DC electric wire where the DC electric power flows are connected in series with each other and a connection point between the higher-potential-side switching device and the lower-potential-side switching device is connected with an AC electric wire where the AC electric power flows; a switching controller that alternately turns on the higher-potential-side switching device and the lower-potential-side switching device in such a way as to sandwich a dead time, with regard to the series circuit for each of respective sets; and a dead time setter that sets the dead time, wherein with regard to the series circuit for each of the respective sets, the dead time setter obtains information on a value of a current that flows in the series circuit; with regard to an obtained current value, the dead time setter corrects a current error caused by a phase shift between a value of an actual current that flows in the series circuit at a time when the dead time is set and the obtained current value, and calculates a corrected current value; then, the dead time setter sets the dead time, based on the corrected current value. ### Claim 2 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter changes a current-error correction value, based on an AC period of a current that flows in the series circuit for each of the respective sets. ### Claim 3 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter increases the current-error correction value, as an AC period of a current that flows in the series circuit for each of the respective sets decreases. ### Claim 4 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter changes the current-error correction value, based on an obtainment delay time that is a delay time caused in obtaining information on a value of a current that flows in the series circuit. ### Claim 5 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter increases the current-error correction value, as an obtainment delay time that is a delay time caused in obtaining information on a value of a current that flows in the series circuit increases. ### Claim 6 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter changes the current-error correction value, based on a control period in the switching controller. ### Claim 7 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter increases the current-error correction value, as a control period in the switching controller increases. ### Claim 8 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter changes the current-error correction value, based on an amplitude of a current that flows in the series circuit for each of the respective sets. ### Claim 9 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter increases the current-error correction value, as an amplitude of a current that flows in the series circuit for each of the respective sets increases. ### Claim 10 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein when an amplitude of a current that flows in the series circuit for each of the respective sets is “0”, the dead time setter sets a dead time to a maximum value that can occur in the electric-power conversion apparatus. ### Claim 11 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter changes the current-error correction value for the series circuit for each of the respective sets, based on a phase, in an AC period, of a current of each of respective phases that flows in the series circuit for each of the respective sets. ### Claim 12 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the dead time setter sets the current-error correction value to a maximum value of a current-value error that can occur in an AC period. ### Claim 13 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein with regard to the series circuit for each of the respective sets, the dead time setter calculates the current-error correction value of a positive value; when the obtained current value is larger than “0”, the dead time setter calculates the corrected current value by subtracting the current-error correction value from the obtained current value while performing lower limiting with “0”; when the obtained current value is smaller than “0”, the dead time setter calculates the corrected current value by adding the current-error correction value to the obtained current value while performing upper limiting with “0”. ### Claim 14 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein when the corrected current value is “0”, the dead time setter sets a dead time to a maximum value that can occur in the electric-power conversion apparatus. ### Claim 15 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the AC electric power obtained through conversion by the electric-power converter is supplied to an AC motor, wherein the electric-power conversion apparatus controls the AC motor, and wherein an AC period of a current that flows in the series circuit for each of the respective sets is determined by a rotation speed of the AC motor. ### Claim 16 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein with regard to a relationship between the dead time and a value of a current that flows in the series circuit, the dead time setter changes the current-error correction value in such a way that the dead time becomes large in a region where the current value is small, in comparison with a region where the current value is large. ### Claim 17 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the switching controller is provided with a current command generator that calculates a current command value, and wherein the dead time setter obtains a current command value for the series circuit for each of the respective sets, as information on a value of a current that flows in the series circuit for each of the respective sets. ### Claim 18 (depends on 1) The electric-power conversion apparatus according to claim 1, further comprising a current detector that detects a current flowing in the series circuit, with regard to the series circuit for each of the respective sets, wherein the dead time setter obtains a current detection value of the series circuit for each of the respective sets, as information on a value of a current that flows in the series circuit for each of the respective sets. ### Claim 19 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein based on temperature information on the switching device, the dead time setter changes the dead time to be calculated based on the corrected current value. ### Claim 20 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein when the electric-power converter has an abnormality, the dead time setter sets the dead time to a maximum value that can occur in the electric-power conversion apparatus. ### Claim 21 (depends on 1) The electric-power conversion apparatus according to claim 1, wherein the switching device is formed by use of a wide bandgap semiconductor.