Uninterruptible power supply diagnosing remaining battery capacity during normal external power source operation

Claim 2

A power supply, which is energized by at least one of an external power source and a battery, and supplies electric power to a load, comprising: means for detecting a battery voltage generated by the battery; means for detecting an amount of electric charges discharged from the battery when the power supply is energized by the battery; and means for detecting a remaining capacity of the battery in accordance with a change in the battery voltage when the external power source is free of power failure; wherein said battery voltage change is a difference between an initial voltage of the battery and an active voltage of the battery obtained when the battery is discharged by a predetermined current for a predetermined period of time.

Claim 3

A power supply according to claim 1, wherein said remaining capacity detecting means includes: means for fetching said predetermined current; means for fetching said battery voltage change; means for calculating an active capacity of said battery from said predetermined current and the battery voltage change, based on a predetermined relationship between the active capacity and the battery voltage change of said battery.

Claim 4

A power supply according to claim 2, wherein said remaining capacity detecting means further includes: means for diagnosing said remaining capacity, in accordance with a predetermined relation between an actually dischargable time of the battery and a ratio of the calculated active capacity to a current of said load.

Claim 5

A power supply according to claim 1, further comprising: means for charging said battery.

Claim 6

A power supply according to claim 4, further comprising: means for controlling the charging of said battery in accordance with a predetermined condition, said predetermined condition being selected from a plurality of charging conditions, such that when the battery voltage exceeds a predetermined reference, one of said charging conditions is selected, and when the battery voltage falls under the predetermined reference, another one of said charging conditions is selected.

Claim 7

A power supply according to claim 1, wherein said power supply includes: a first AC-AC power converter having a first rectifier means for converting input AC power from said external power source into first DC power, and a first inverter means for converting the first DC power into output AC power supplied to said load; a second AC-AC power converter having a second rectifier means for converting said input AC power into second DC power, and a second inverter means for converting the second DC power into said output AC power; and means for feeding DC power from said battery to each of said first and second inverter means.

Claim 8

A power supply according to claim 1, further comprising: means for charging said battery by energy obtained from said external power source.

Claim 9

A power supply according to claim 7, further comprising: means for controlling said charging means, such that when the battery voltage exceeds a predetermined reference, a first charging condition is selected, and when the battery voltage falls under the predetermined reference, a second charging condition is selected.

Claim 10

A power supply according to claim 1, wherein said power supply includes: a first power converter having a first rectifier means for converting input AC power from said external power source into first DC power, and a first means for converting the first DC power into output power supplied to said load; a second power converter having a second rectifier means for converting said input AC power into second DC power, and a second means for converting the second DC power into said output power; and means for feeding DC power from said battery to each of said first and second means.

Claim 11

A power supply apparatus in which when power from an input AC power supply is power-converted by said power supply apparatus and is supplied to a load, even if said input AC power supply fails for a short period of time, power is supplied from a storage battery to the load through a DC circuit of said power supply apparatus, and stable power can be continuously supplied to the load during the power failure, said power supply apparatus comprising: means for causing said storage battery to supply at least part of power to be supplied to the load for a first predetermined period of time while said input AC power supply is normally operated; and means for diagnosing a remaining capacity of said storage battery on the basis of a charge which is discharged from said storage battery during the first predetermined period of time; wherein said means for diagnosing includes means for detecting said remaining capacity of the battery in accordance with a change in the battery voltage when said AC power supply is operating, said change being a difference between an initial voltage of the battery and an active voltage of the battery obtained when the batter is discharged by a predetermined current for a second predetermined period of time.

Claim 12

A power supply apparatus in which when power from an input AC power supply is power-converted by said power supply apparatus and is supplied to a load, even if said input AC power supply fails for a short period of time, power is supplied from a storage battery to the load through a DC circuit of said power supply apparatus, and stable power can be continuously supplied to the load during the power failure, said power supply apparatus comprising: means for causing said storage battery to supply at least part of power to be supplied to the load for a first predetermined period of time while said input AC power supply is normally operated; and means for diagnosing a remaining capacity of said storage battery on the basis of a charge which is discharged from said storage battery during the first predetermined period of time; wherein said means for diagnosing includes means for detecting said remaining capacity of the battery in accordance with a change in the battery voltage when said AC power supply is operating, said change being a difference between an initial voltage of the battery and an active voltage of the battery obtained when the batter is discharged by a predetermined current for a second predetermined period of time.

Claim 13

A power supply apparatus according to claim 10, wherein said diagnosing means further comprises means for determining whether said predetermined current is held at a predetermined current value, and for comparing said predetermined current and said change in battery voltage to a battery capacity relationship derived beforehand to determine said remaining capacity.

Claim 14

A power supply apparatus in which when power from an input AC power supply is power-converted by said power supply apparatus and is supplied to a load, even if said input AC power supply fails for a short period of time, power is supplied form a storage battery to the load through a DC circuit of said power supply apparatus, and stable power can be continuously supplied to the load during the power failure, said power supply apparatus comprising: means for controlling said power supply so as to cause said storage battery to supply at least part of power to be supplied to the load for a first predetermined period of time while said input AC power supply is normally operated; and means for diagnosing a power failure backup time of said storage battery on the basis of a load capacity and a charge which is discharged from said storage battery during the first predetermined period of time; wherein said means for diagnosing includes means for detecting a remaining capacity of the battery in accordance with a change in the battery voltage when said AC power supply is operating, said change being a difference between an initial voltage of the battery and an active voltage of the battery obtained when the battery is discharged by a predetermined current for a second predetermined period of time.

Claim 15

A power supply apparatus in which when power from an input AC power supply is power-converted by said power supply apparatus and is supplied to a load, even if said input AC power supply fails for a short period of time, power is supplied form a storage battery to the load through a DC circuit of said power supply apparatus, and stable power can be continuously supplied to the load during the power failure, said power supply apparatus comprising: means for controlling said power supply so as to cause said storage battery to supply at least part of power to be supplied to the load for a first predetermined period of time while said input AC power supply is normally operated; and means for diagnosing a power failure backup time of said storage battery on the basis of a load capacity and a charge which is discharged from said storage battery during the first predetermined period of time; wherein said means for diagnosing includes means for detecting a remaining capacity of the battery in accordance with a change in the battery voltage when said AC power supply is operating, said change being a difference between an initial voltage of the battery and an active voltage of the battery obtained when the battery is discharged by a predetermined current for a second predetermined period of time.

Claim 16

A power supply apparatus according to claim 12, wherein said diagnosing means further comprises means for determining whether said predetermined current is held at a predetermined current value, and for comparing said predetermined current and said change in battery voltage to a battery capacity relationship derived beforehand to determine said remaining capacity.

Claim 17

A power supply apparatus in which when an input AC power supply fails, power can be uninterruptibly supplied from a storage battery to a load, comprising: means for performing an equalizing charge operation of said storage battery for a first predetermined period of time and subsequently switching the equalizing charge operation to a floating charge operation while said input AC power supply is normally operated; and means for diagnosing a capacity of said storage battery on the basis of a charge which is discharged from said storage battery for a desired period of time when the floating charge operation is performed. wherein said means for diagnosing include means for detecting a remaining capacity of the battery in accordance with a change in the battery voltage when said AC power supply is operating, said change being a difference between an initial voltage of the battery and an active voltage of the battery obtained when the battery is discharged by a predetermined current for a second predetermined period of time.

Claim 18

A power supply apparatus in which when an input AC power supply fails, power can be uninterruptibly supplied from a storage battery to a load, comprising: means for performing an equalizing charge operation of said storage battery for a first predetermined period of time and subsequently switching the equalizing charge operation to a floating charge operation while said input AC power supply is normally operated; and means for diagnosing a capacity of said storage battery on the basis of a charge which is discharged from said storage battery for a desired period of time when the floating charge operation is performed. wherein said means for diagnosing include means for detecting a remaining capacity of the battery in accordance with a change in the battery voltage when said AC power supply is operating, said change being a difference between an initial voltage of the battery and an active voltage of the battery obtained when the battery is discharged by a predetermined current for a second predetermined period of time.

Claim 19

A power supply apparatus according to claim 14, wherein said diagnosing means further comprises means for determining whether said predetermined current is held at a predetermined current value, and for comparing said predetermined current and said change in battery voltage to a battery capacity relationship derived beforehand to determine said remaining capacity.

Claim 20

A power supply apparatus in which when power from an input AC power supply is power-converted by said power supply apparatus and is supplied to a load, even if said input AC power supply fails for a short period of time, power is supplied from a storage battery to the load through a DC circuit of said power supply apparatus, and stable power can be continuously supplied to the load during the power failure, said power supply apparatus comprising: means for causing said storage battery to supply at least part of power to be supplied to the load for a first predetermined period of time while said input AC power supply is normally operated; and means for diagnosing a remaining capacity of said storage battery on the basis of a charge which is discharged from said storage battery during the predetermined period of time, thereby automatically performing equalizing charging in accordance with the diagnosis result; wherein said means for diagnosing include means for detecting a remaining capacity of the battery in accordance with a change in the battery voltage when said AC power supply is operating, said change being a difference between an initial voltage of the battery and an active voltage of the battery obtained when the battery is discharged by a predetermined current for said predetermined period of time.

Claim 21

A power supply apparatus in which when power from an input AC power supply is power-converted by said power supply apparatus and is supplied to a load, even if said input AC power supply fails for a short period of time, power is supplied from a storage battery to the load through a DC circuit of said power supply apparatus, and stable power can be continuously supplied to the load during the power failure, said power supply apparatus comprising: means for causing said storage battery to supply at least part of power to be supplied to the load for a first predetermined period of time while said input AC power supply is normally operated; and means for diagnosing a remaining capacity of said storage battery on the basis of a charge which is discharged from said storage battery during the predetermined period of time, thereby automatically performing equalizing charging in accordance with the diagnosis result; wherein said means for diagnosing include means for detecting a remaining capacity of the battery in accordance with a change in the battery voltage when said AC power supply is operating, said change being a difference between an initial voltage of the battery and an active voltage of the battery obtained when the battery is discharged by a predetermined current for said predetermined period of time.

Claim 22

A power supply apparatus according to claim 15, wherein said diagnosing means further comprises means for determining whether said predetermined current is held at a predetermined current value, and for comparing said predetermined current and said change in battery voltage to a battery capacity relationship derived beforehand to determine said remaining capacity.