# US 10,481,184 B2 · Input-voltage-abnormality detection method and power source device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,184 B2 - Document ID: US10481184B2 - Status: Granted - Kind: B2 - Application number: 15/747,296 - Filed: 2016-06-07 - Published: 2018-08-02 - Granted: 2019-11-19 - Earliest claimed: 2015-08-04 - Assignees: Sumitomo Electric Industries, Ltd. - Applicants: Sumitomo Electric Industries, Ltd. - Inventors: Fumio Urakawa; Tetsuo Akita; Koichi Takeshita - Web page: https://patentgrep.com/patent/US10481184B2 ## CPC - G01R 19/16547: {voltage or current in AC supplies (switching for protection H02H; circuits for emergency power supply H02J9/00)} - G01R 31/42: AC power supplies - H02H 3/24: responsive to undervoltage or no-voltage {(H02H3/207 takes precedence)} - H02H 3/50: responsive to the appearance of abnormal wave forms, e.g. AC in DC installations - H02H 7/20: for electronic equipment (for converters H02H7/10; for electric measuring instruments G01R1/36; for DC voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08) - H02J 9/062: {for AC powered loads} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - 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 ## Abstract This abnormality detection method for a single-phase AC input voltage is executed by a control unit having a function of a phase locked loop, and includes: sequentially generating a simulated voltage waveform with a phase synchronized with the input voltage, by using the phase locked loop; and within a period until a next update of the generated simulated voltage waveform, comparing the instantaneous value of the input voltage with the simulated voltage waveform, and when the instantaneous value of the input voltage changes from a state of being along the simulated voltage waveform to a state of not being along the simulated voltage waveform, determining that the input voltage is abnormal. ## Claims ### Claim 1 A power supply device comprising: a single-phase AC path from an input end to an output end in the power supply device; a first voltage sensor configured to detect an input voltage at the input end; a second voltage sensor configured to detect an output voltage at the output end; a conversion unit connected to the AC path and being capable of bidirectional power conversion; a storage battery connected to the AC path via the conversion unit; an AC switch provided between the input end and a point at which the conversion unit is connected to the AC path; and a control unit configured to control the conversion unit and the AC switch, thereby having a current conduction mode in which a power is supplied from the input end through the AC switch which is closed and the AC path, to reach the output end and thus supplied to a load connected to the output end, and a storage battery discharge mode in which the AC switch is opened and a power is supplied from the storage battery to the load via the conversion unit, wherein the control unit has a function of a phase locked loop, and sequentially generates a simulated voltage waveform with a phase synchronized with the input voltage, by using the phase locked loop, and within a period until a next update of the generated simulated voltage waveform, compares an instantaneous value of the input voltage with the simulated voltage waveform, and when the instantaneous value of the input voltage changes from a state of being along the simulated voltage waveform to a state of not being along the simulated voltage waveform, determines that the input voltage is abnormal, and shifts from the current conduction mode to the storage battery discharge mode. ### Claim 2 (depends on 1) The power supply device according to claim 1, wherein when a difference voltage between the instantaneous value of the input voltage and the simulated voltage waveform is greater than a threshold value for abnormality detection, the control unit determines that the instantaneous value of the input voltage is in the state of not being along the simulated voltage waveform. ### Claim 3 (depends on 2) The power supply device according to claim 2, wherein when a state in which the difference voltage is greater than the threshold value has continued during a predetermined period, the control unit determines that the input voltage is abnormal. ### Claim 4 (depends on 2) The power supply device according to claim 2, wherein when the input voltage is restored after the shifting to the storage battery discharge mode, the control unit synchronizes a phase of an output voltage of the conversion unit with the input voltage, by using the phase locked loop, and when the phase synchronization is established, the control unit shifts from the storage battery discharge mode to the current conduction mode. ### Claim 5 (depends on 4) The power supply device according to claim 4, wherein when the difference voltage has become smaller than a threshold value for synchronization detection, the control unit determines that the phase synchronization is established. ### Claim 6 (depends on 5) The power supply device according to claim 5, wherein the threshold value for abnormality detection and the threshold value for synchronization detection are values different from each other. ### Claim 7 (depends on 3) The power supply device according to claim 3, wherein when the input voltage is restored after the shifting to the storage battery discharge mode, the control unit synchronizes a phase of an output voltage of the conversion unit with the input voltage, by using the phase locked loop, and when the phase synchronization is established, the control unit shifts from the storage battery discharge mode to the current conduction mode. ### Claim 8 (depends on 7) The power supply device according to claim 7, wherein when the difference voltage has become smaller than a threshold value for synchronization detection, the control unit determines that the phase synchronization is established. ### Claim 9 (depends on 8) The power supply device according to claim 8, wherein the threshold value for abnormality detection and the threshold value for synchronization detection are values different from each other.