# US 12,113,457 B2 · Electric-power converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,457 B2 - Document ID: US12113457B2 - Status: Granted - Kind: B2 - Application number: 18/005,765 - Filed: 2020-10-28 - Published: 2023-10-05 - Granted: 2024-10-08 - Earliest claimed: 2020-10-28 - Assignees: TMEIC Corporation - Applicants: TMEIC Corporation - Inventors: Kazuki Aoyagi; Issei Fukasawa - Web page: https://patentgrep.com/patent/US12113457B2 ## CPC - H02M 7/493: the static converters being arranged for operation in parallel - H02H 7/1213: {for DC-DC converters} - H02H 7/122: for inverters, i.e. DC/AC converters - H02J 3/38: Arrangements for feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel - H02M 1/0009: {Devices or circuits for detecting current in a converter} - H02M 1/32: Means for protecting converters other than automatic disconnection - H02S 40/32: comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules - H02S 40/30: Electrical components - 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) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02S: GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES (obtaining electrical energy from radioactive sources G21H1/12; light sensitive inorganic semiconductor devices H10F; light sensitive organic semiconductor devices H10K30/00; thermoelectric devices H10N10/00; pyroelectric devices H10N15/00) ## Abstract An electric-power converter includes a plurality of direct-current power supplies, a plurality of power conversion circuits provided corresponding to the respective direct-current power supplies, an alternating-current power system configured to cause a plurality of alternating-current ends provided in the respective power conversion circuits to be directly connected in parallel through a parallel connection point, and to supply the alternating-current power output from the plurality of alternating-current ends to an alternating-current side through the parallel connection point, a plurality of grounding wires each configured to connect at least two of a plurality of direct-current negative buses between the plurality of direct-current power supplies and the plurality of power conversion circuits, to earth, and a plurality of diodes inserted in series into the respective grounding wires, and each including a cathode side connected to the corresponding direct-current negative bus and an anode side grounded. ## Claims ### Claim 1 An electric-power converter, comprising: a plurality of direct-current power supplies; a plurality of power conversion circuits provided corresponding to the respective direct-current power supplies, and configured to receive, from direct-current ends, direct-current power supplied from the respective corresponding direct-current power supplies through direct-current buses and to convert the direct-current power into alternating-current power; an alternating-current power system configured to cause a plurality of alternating-current ends provided in the respective power conversion circuits to be directly connected in parallel through a parallel connection point, and to supply the alternating-current power output from the plurality of alternating-current ends to an alternating-current side through the parallel connection point; a plurality of grounding wires each configured to connect at least two of a plurality of direct-current negative buses between the plurality of direct-current power supplies and the plurality of power conversion circuits, to earth; and a plurality of diodes inserted in series into the respective grounding wires, and each including a cathode side connected to the corresponding direct-current negative bus and an anode side grounded. ### Claim 2 (depends on 1) The electric-power converter according to claim 1, further comprising: a plurality of current detectors configured to detect currents flowing through the respective diodes; and control circuitry configured to monitor the currents detected by the plurality of current detectors. ### Claim 3 (depends on 2) The electric-power converter according to claim 2, further comprising a plurality of first breakers inserted in series into the respective direct-current buses, and configured to disconnect the respective direct-current buses, wherein when any of the plurality of current detectors detects current, the control circuitry issues an open operation instruction to the plurality of first breakers. ### Claim 4 (depends on 2) The electric-power converter according to claim 2, further comprising a plurality of second breakers inserted into the respective grounding wires in series to the respective diodes, and configured to disconnect the respective grounding wires, wherein when any of the plurality of current detectors detects current, the control circuitry issues an open operation instruction to the plurality of second breakers. ### Claim 5 (depends on 2) The electric-power converter according to claim 2, further comprising third breakers inserted into respective electric paths of the alternating-current power system, and configured to disconnect the respective electric paths, wherein when any of the plurality of current detectors detects current, the control circuitry issues an open operation instruction to the third breakers. ### Claim 6 (depends on 1) The electric-power converter according to claim 1, further comprising: a plurality of fuses inserted into the respective grounding wires in series to the respective diodes, and configured to be blown out when a current greater than or equal to a predetermined threshold flows through the respective diodes; a plurality of voltage detectors configured to detect potential variations of the direct-current power at the respective direct-current ends; and control circuitry configured to monitor the potential variations detected by the plurality of voltage detectors when the fuses are blown out. ### Claim 7 (depends on 6) The electric-power converter according to claim 6, further comprising a plurality of first breakers inserted in series into the respective direct-current buses, and configured to disconnect the respective direct-current buses, wherein when any of the plurality of voltage detectors detects the potential variation, the control circuitry issues an open operation instruction to the plurality of first breakers. ### Claim 8 (depends on 6) The electric-power converter according to claim 6, further comprising a plurality of second breakers inserted into the respective grounding wires in series to the respective diodes, and configured to disconnect the respective grounding wires, wherein when any of the plurality of voltage detectors detects the potential variation, the control circuitry issues an open operation instruction to the plurality of second breakers. ### Claim 9 (depends on 6) The electric-power converter according to claim 6, further comprising third breakers inserted into respective electric paths of the alternating-current power system, and configured to disconnect the respective electric paths, wherein when any of the plurality of voltage detectors detects the potential variation, the control circuitry issues an open operation instruction to the third breakers. ### Claim 10 (depends on 1) The electric-power converter according to claim 1, further comprising: a plurality of fuses inserted into the respective grounding wires in series to the respective diodes, and configured to be blown out when a current greater than or equal to a predetermined threshold flows through the respective diodes; a plurality of switches provided in the respective fuses, and configured to be opened when the fuse provided with the switch itself is blown out; and control circuitry configured to monitor open operation of the switches. ### Claim 11 (depends on 1) The electric-power converter according to claim 1, wherein the direct-current power supplies are solar cells. ### Claim 12 (depends on 3) The electric-power converter according to claim 3, further comprising a plurality of second breakers inserted into the respective grounding wires in series to the respective diodes, and configured to disconnect the respective grounding wires, wherein when any of the plurality of current detectors detects the current, the control circuitry issues an open operation instruction to the plurality of second breakers. ### Claim 13 (depends on 3) The electric-power converter according to claim 3, further comprising third breakers inserted into respective electric paths of the alternating-current power system, and configured to disconnect the respective electric paths, wherein when any of the plurality of current detectors detects the current, the control circuitry issues an open operation instruction to the third breakers. ### Claim 14 (depends on 4) The electric-power converter according to claim 4, further comprising third breakers inserted into respective electric paths of the alternating-current power system, and configured to disconnect the respective electric paths, wherein when any of the plurality of current detectors detects the current, the control circuitry issues an open operation instruction to the third breakers. ### Claim 15 (depends on 7) The electric-power converter according to claim 7, further comprising a plurality of second breakers inserted into the respective grounding wires in series to the respective diodes, and configured to disconnect the respective grounding wires, wherein when any of the plurality of voltage detectors detects the potential variation, the control circuitry issues an open operation instruction to the plurality of second breakers. ### Claim 16 (depends on 7) The electric-power converter according to claim 7, further comprising third breakers inserted into respective electric paths of the alternating-current power system, and configured to disconnect the respective electric paths, wherein when any of the plurality of voltage detectors detects the potential variation, the control circuitry issues an open operation instruction to the third breakers. ### Claim 17 (depends on 8) The electric-power converter according to claim 8, further comprising third breakers inserted into respective electric paths of the alternating-current power system, and configured to disconnect the respective electric paths, wherein when any of the plurality of voltage detectors detects the potential variation, the control circuitry issues an open operation instruction to the third breakers. ### Claim 18 (depends on 2) The electric-power converter according to claim 2, wherein the direct-current power supplies are solar cells. ### Claim 19 (depends on 3) The electric-power converter according to claim 3, wherein the direct-current power supplies are solar cells. ### Claim 20 (depends on 4) The electric-power converter according to claim 4, wherein the direct-current power supplies are solar cells.