# US 12,224,621 B2 · Power supply device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,621 B2 - Document ID: US12224621B2 - Status: Granted - Kind: B2 - Application number: 17/615,178 - Filed: 2019-12-26 - Published: 2022-07-28 - Granted: 2025-02-11 - Earliest claimed: 2019-12-26 - Assignees: TMEIC Corporation - Applicants: TMEIC Corporation - Inventors: Hidenobu Tajima - Web page: https://patentgrep.com/patent/US12224621B2 ## CPC - H02J 9/062: {for AC powered loads} - H02M 3/158: including plural semiconductor devices as final control devices for a single load - H02J 7/345: {using capacitors as storage or buffering devices} - H02J 7/80: including monitoring or indicating arrangements - H02J 7/975: {in response to temperature} - H02J 9/068: {Electronic means for switching from one power supply to another power supply, e.g. to avoid parallel connection} - H02M 1/14: Arrangements for reducing ripples from DC input or output - H02M 1/327: {against abnormal temperatures} - H02J 2207/20: Charging or discharging characterised by the power electronics converter - H02M 1/007: {Plural converter units in cascade (push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826)} - H02M 7/217: using semiconductor devices only - H02M 7/537: using semiconductor devices only, e.g. single switched pulse inverters - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - 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) ## Abstract A power supply device includes an inverter, a voltage converter, a capacitor, a current detector, a counter, and a controller. The inverter converts DC power into AC power and supplies the converted AC power to a load. The voltage converter performs voltage conversion for a DC voltage from a battery. The capacitor smoothes the DC voltage from the voltage converter and inputs the smoothed DC voltage to the inverter. The current detector detects a battery current flowing from the battery into the voltage converter. The counter measures a discharge time of the battery. The controller stops the voltage converter when the measured discharge time of the battery exceeds a discharge permissible time. Based on an output from the current detector, the controller sets the discharge permissible time to be shorter as the battery current is higher when the battery current exceeds a threshold value during discharging of the battery. ## Claims ### Claim 1 A power supply device comprising: an inverter that converts DC power into AC power and supplies the AC power to a load; a voltage converter that performs voltage conversion for a DC voltage from a battery; a capacitor that smoothes the DC voltage from the voltage converter and inputs the smoothed DC voltage to the inverter; a current detector that detects a battery current flowing from the battery into the voltage converter; a counter that measures a discharge time of the battery; and a controller that controls the voltage converter, wherein the controller stops the voltage converter when the measured discharge time of the battery exceeds a discharge permissible time, and when the battery current exceeds a threshold value during discharging of the battery, the controller sets the discharge permissible time based on an output from the current detector such that the discharge permissible time is shorter as the battery current is higher. ### Claim 2 (depends on 1) The power supply device according to claim 1, further comprising a voltage detector that detects a voltage of the battery, wherein the controller stops the voltage converter when the discharge time of the battery exceeds the discharge permissible time or when the detected voltage of the battery falls below a discharge cut-off voltage. ### Claim 3 (depends on 1) The power supply device according to claim 1, further comprising a converter that converts AC power from a commercial AC power supply into DC power, wherein when the commercial AC power supply is in a normal state, the controller controls the voltage converter to charge the battery with electric power from the converter, and when a power interruption occurs in the commercial AC power supply, the controller controls the voltage converter to discharge electric power from the battery to the inverter. ### Claim 4 (depends on 1) The power supply device according to claim 1, wherein the voltage converter includes a switching element, and a reactor to which a voltage switched by the switching element is applied. ### Claim 5 (depends on 2) The power supply device according to claim 2, further comprising a converter that converts AC power from a commercial AC power supply into DC power, wherein when the commercial AC power supply is in a normal state, the controller controls the voltage converter to charge the battery with electric power from the converter, and when a power interruption occurs in the commercial AC power supply, the controller controls the voltage converter to discharge electric power from the battery to the inverter. ### Claim 6 (depends on 2) The power supply device according to claim 2, wherein the voltage converter includes a switching element, and a reactor to which a voltage switched by the switching element is applied. ### Claim 7 (depends on 3) The power supply device according to claim 3, wherein the voltage converter includes a switching element, and a reactor to which a voltage switched by the switching element is applied. ### Claim 8 (depends on 5) The power supply device according to claim 5, wherein the voltage converter includes a switching element, and a reactor to which a voltage switched by the switching element is applied.