JP5587941B2 - Uninterruptible power supply and uninterruptible power supply method - Google Patents

Description

  The present invention relates to an uninterruptible power supply and an uninterruptible power supply method, and more particularly to an uninterruptible power supply and an uninterruptible power supply method that prevent battery deterioration.

  Generally, an uninterruptible power supply supplies electric power to a load from an AC commercial power supply, and stores electric power in a battery such as a lithium ion secondary battery provided in the uninterruptible power supply. When a power failure occurs due to a power failure or the like of the AC commercial power supply, the power stored in the battery is supplied to the load to achieve uninterruptible load.

  When the battery has deteriorated, the uninterruptible power supply cannot supply power for the expected time to the load when a power failure occurs. As one of the factors that accelerate the deterioration of the battery, there are electrical usage conditions (the number of discharges / charges, excessive discharge (overdischarge), excessive charge (overcharge), etc.).

  Patent Document 1 discloses an uninterruptible power supply capable of preventing battery deterioration due to excessive charging. The uninterruptible power supply device disclosed in Patent Document 1 includes a discharge time acquisition unit, a charge control unit, and a battery such as a lithium ion secondary battery. After the battery is fully charged, for example, the discharge time acquisition means periodically discharges the battery by connecting a discharging resistor between both ends of the battery. And the both-ends voltage of a battery and the discharge time (fall time) until this both-ends voltage falls to a predetermined setting voltage value are measured. The charge control means compares the descent time with a required discharge time corresponding to a predetermined load backup time required for the uninterruptible power supply. And based on this comparison result, it sets so that a charging voltage may be raised / lowered and it may become an optimal charging voltage. Then, the battery is charged so that the voltage across the battery becomes the optimum charging voltage. Here, the optimum charging voltage is a charging voltage that can satisfy the load backup time required for the uninterruptible power supply. In other words, the optimum charging voltage is the load capacity during the load backup time required for this uninterruptible power supply due to the battery capacity when the battery is charged until the voltage across the battery reaches this charging voltage. It is a charging voltage that can supply power.

  Thus, this uninterruptible power supply measures the discharge time (fall time) until the both-ends voltage of a battery falls to a setting voltage value by discharging a battery regularly by a discharge time acquisition means. Then, based on the comparison result between this drop time and the required discharge time corresponding to the load backup time required for the uninterruptible power supply, the charging voltage is set to the optimum charging voltage, and the battery The battery is charged so that the voltage between both ends becomes this optimum charging voltage.

  That is, the uninterruptible power supply disclosed in Patent Document 1 periodically sets an optimum charging voltage according to a predetermined backup time of the load, and the battery voltage is set to the optimum charging voltage. To charge. For this reason, it is possible to prevent the battery from being deteriorated due to an excessive charging voltage.

JP 2005-278329 A

  The uninterruptible power supply disclosed in Patent Document 1 described above periodically sets an optimum charging voltage according to a predetermined backup time of the load, and the battery voltage is set to the optimum charging voltage. To charge. In other words, this uninterruptible power supply does not set the optimum charging voltage according to the backup time in real time, but sets it periodically. For this reason, in an environment where the power consumption of the load fluctuates greatly, the battery may not be charged so as to satisfy the actually required backup time. In this case, when a power failure occurs, power for the expected time cannot be supplied to the load, and the load connected to the uninterruptible power supply may be subject to unexpected power interruption. There is a problem.

  The object of the present invention is to solve the above-mentioned problems and to charge the battery so as to satisfy the necessary backup time while preventing the battery from deteriorating even in an environment where the power consumption of the load fluctuates greatly. An uninterruptible power supply and an uninterruptible power supply method that can be provided.

The uninterruptible power supply of the present invention is an uninterruptible power supply that supplies power to a load by an external power source and supplies power to the load by a battery when there is no input of the external power source, and the battery, Calculate the current load factor indicating the degree of power supply to the load for the uninterruptible power supply and the degree of consumption of the battery, and at a reference backup time predetermined according to the uninterruptible power supply, By multiplying the complement of the load factor and the consumption rate, a backup time deriving unit that calculates in real time a current backup time indicating a period in which the load can be backed up by the battery , and the load by the external power source When the backup time deriving unit calculates the current backup time when a predetermined threshold value is being supplied When it is less than, and a, a charging unit for charging the battery.

The uninterruptible power supply method of the present invention supplies uninterruptible power supply using an uninterruptible power supply that supplies power to a load by an external power supply and supplies power to the load by a battery when the external power supply is not input. A method of calculating a current load factor indicating a degree of power supply to the load to the uninterruptible power supply and a consumption level of the battery, and a reference backup predetermined according to the uninterruptible power supply By multiplying the time by the complement of the load factor and the consumption rate , a current backup time indicating a period during which the load can be backed up by the battery is calculated in real time, and the load is powered by the external power source. When the calculated current backup time becomes less than a predetermined threshold time, the battery is charged. , It is way.

  According to the present invention, an uninterruptible power supply capable of charging a battery so as to satisfy a necessary backup time while preventing deterioration of the battery even in an environment where the power consumption of the load greatly fluctuates. An uninterruptible power supply method can be provided.

It is a figure which shows an example of the uninterruptible power supply which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the uninterruptible power supply which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows an example of operation | movement of embodiment of this invention.

Next, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing an example of an uninterruptible power supply according to the first embodiment of the present invention.

  The uninterruptible power supply 1 according to the present embodiment includes a battery 2, a backup time deriving unit 3, and a charging unit 4.

  FIG. 1 also shows an external power supply 5 that is input to the uninterruptible power supply 1 and a load 6 that supplies power from the uninterruptible power supply 1.

  The uninterruptible power supply 1 supplies power to the load 6 by an external power source 5 input from the outside, and supplies power to the load 6 by a battery 2 provided in advance when there is no input from the external power source 5.

  The battery 2 is a secondary battery including a lithium ion battery, for example.

The backup time deriving unit 3 calculates the current load factor indicating the degree of power supply to the load 6 to the uninterruptible power supply 1 and the current wear level of the battery 2, and uses this load rate and wear rate. The current backup time of the battery 2 with respect to the load 6 is calculated in real time.

For example, the backup time deriving unit 3 calculates the load factor at the reference backup time that is predetermined according to the rated capacity (rated power consumption (W)) of the load 6 connected to the uninterruptible power supply 1 itself. The current backup time is calculated by multiplying the calculated degree of wear similarly to the complement of.

  Here, the backup time indicates a period during which the load 6 can be backed up by the battery 2. The power supply degree to the load 6 indicates, for example, the magnitude of power consumption of the load 6, and the load factor is the load 6 connected to the uninterruptible power supply 1 for the uninterruptible power supply 1. Indicates the degree of burden imposed for Further, the consumption level indicates the level of consumption. The reference backup time (H) generally indicates a standard time for backing up the load 6 connected to the uninterruptible power supply 1. This time is determined in advance according to the rated output capacity (W) of the uninterruptible power supply 1 and the rated capacity (rated power consumption (W)) of the load 6 connected to the uninterruptible power supply 1. It's time. The uninterruptible power supply 1 stores a reference backup time corresponding to the rated capacity of the load 6 in advance. Moreover, when connecting the load 6 to this uninterruptible power supply 1, the data of the rated capacity of the load 6 is input based on a user's operation, and this data is stored in the uninterruptible power supply 1. When calculating the current backup time, the backup time deriving unit 3 takes out the reference backup time corresponding to the stored rated capacity of the load 6.

  When the charging unit 4 supplies power to the load 6 from the external power source 5, the battery 2 is turned on when the current backup time calculated in real time by the backup time deriving unit 3 is less than a predetermined threshold time. To charge. The predetermined threshold time indicates a backup time desired by the user. That is, it shows the time required to back up the load 6 connected to the uninterruptible power supply 1. This threshold time is normally set to a reference backup time (H) or less by a user operation, and is stored in the uninterruptible power supply 1 in advance.

  Thus, according to the first embodiment, the current backup time of the battery with respect to the load is calculated in real time, and the calculated backup time is determined in advance to be required to be backed up with respect to this load. When the battery becomes less than the threshold time, the battery is charged. For this reason, according to the first embodiment, the battery is charged when the calculated backup time becomes less than a predetermined threshold time required to be backed up. Can be avoided. For this reason, deterioration of the battery can be prevented.

Further, according to the first embodiment, the current backup time with respect to the battery load is calculated in real time. For this reason, since the current backup time is calculated, the battery can be charged to satisfy the required backup time even in an environment where the power consumption of the load fluctuates greatly.
(Second Embodiment)
FIG. 2 is a diagram illustrating an example of an uninterruptible power supply apparatus according to the second embodiment of the present invention.

  The uninterruptible power supply 1 according to the present embodiment includes a battery 2, a backup time deriving unit 3, a charging unit 4, a storage unit 10, a control unit 11, an AC / DC conversion unit 12, and a power switching unit. 13. The backup time deriving unit 3 includes a load factor calculation unit 8, a battery consumption level calculation unit 7, and a backup time calculation unit 9.

  FIG. 2 also shows an external power supply 5 that is input to the uninterruptible power supply 1 and a load 6 that supplies power from the uninterruptible power supply 1.

  The battery 2 is a secondary battery including a lithium ion battery, for example.

  The storage unit 10 stores in advance the rated output capacity (watts (W)) of its own uninterruptible power supply 1 and the initial battery voltage (volt (V)) of the battery 2 mounted on the uninterruptible power supply 1. It is. The rated output capacity (watt (W)) of the uninterruptible power supply 1 is a predetermined output capacity that the uninterruptible power supply 1 can output. The initial battery voltage (V) is a battery voltage at the time of factory shipment mounted on the uninterruptible power supply 1, and indicates a voltage across the battery 2 when the battery 2 is fully charged.

  The storage unit 10 stores in advance a reference backup time (H) corresponding to the rated capacity (W) of the load 6. The standard backup time (H) generally indicates a time for backing up the connected load 6 as a standard, and is connected to the rated output capacity (W) of the uninterruptible power supply 1 and the uninterruptible power supply 1. This time is predetermined according to the rated capacity of the load 6 (rated power consumption (W)). For example, when the load 6 is connected to the uninterruptible power supply 1, the rated capacity data of the load 6 is input based on a user operation and stored in the storage unit 10.

  The threshold time (H) indicates a backup time desired by the user. For example, when the load 6 is connected to the uninterruptible power supply 1, the threshold time (H) is input based on a user operation and stored in the storage unit 10. Keep it. The threshold time is normally set to a reference backup time (H) or less.

  The load factor calculation unit 8 in the backup time deriving unit 3 calculates a current load factor indicating the degree of power supply to the load 6 for the uninterruptible power supply 1. The supply degree of power to the load 6 is, for example, the power consumption of the load 6, and the load factor indicates the degree of burden imposed on the uninterruptible power supply 1 for the load 6.

  The battery consumption level calculation unit 7 in the backup time deriving unit 3 calculates the current consumption level of the battery 2. The degree of wear represents the degree of wear.

  The backup time calculation unit 9 in the backup time deriving unit 3 calculates the current backup time of the battery 2 with respect to the load 6 in real time using the complement of the calculated load factor and the calculated degree of consumption. The backup time indicates a period during which the load 6 can be backed up by the battery 2.

  The control unit 11 outputs a charging instruction to the charging unit 4 when the current backup time calculated by the backup time deriving unit 3 is less than the threshold time stored in the storage unit 10.

  The charging unit 4 receives the charging instruction from the control unit 11 and charges the battery 2.

  The AC / DC conversion unit 12 converts the alternating current of the external power supply 5 input from the outside into direct current and supplies the direct current to each unit of the uninterruptible power supply 1.

  The power supply switching unit 13 supplies power to the load 6 or does not supply power to the load 6 according to an instruction from the control unit 11. When supplying power to the load 6, the power from the external power supply 5 and the power from the battery 2 are switched, and direct current is converted into alternating current and supplied to the load 6.

  When there is an input from the external power supply 5, the control unit 11 instructs the power supply switching unit 13 to supply power from the external power supply 5 to the load 6. When there is no input from the external power supply 5, the power supply switching unit 13 is instructed to supply power from the battery 2 to the load 6 depending on the state of the load 6, or the power supply is switched so that power is not supplied to the load 6. The unit 13 is instructed.

  Next, the operation of the uninterruptible power supply according to the embodiment of the present invention will be described in detail with reference to FIG.

  FIG. 3 is a flowchart showing an example of the operation of the embodiment of the present invention.

  In step S1 of FIG. 3, the power switch of the uninterruptible power supply 1 is turned on, and the uninterruptible power supply 1 operates.

  In step S <b> 2 of FIG. 3, the control unit 11 detects an input from the external power supply 5, and instructs the power supply switching unit 13 to supply power from the external power supply 5 to the load 6. Then, the power source switching unit 13 performs switching so as to supply power from the external power source 5 to the load 6 according to an instruction from the control unit 11.

  In step S3 in FIG. 3, the load factor calculation unit 8 applies the current power consumption (W) (for example, 40 (W)) of the load 6 to the current flowing from the uninterruptible power supply 1 to the load 6 and the load 6. For example, the voltage is calculated by measuring in real time. Then, the current load factor is obtained by dividing the calculated power consumption (W) by the rated output capacity (W) (for example, 980 (W)) of the uninterruptible power supply 1 stored in the storage unit 10. Is calculated in real time, for example. That is, current load factor = calculated power consumption (W) / rated output capacity (W) of uninterruptible power supply 1, for example, 40/980 = 0.041. Usually less than 1.

  In step S4 of FIG. 3, the battery consumption level calculation unit 7 measures the current battery voltage (V) in real time, for example, and stores the measured battery voltage (V) (for example, 6 (V)) in the storage unit 10. By dividing by the stored initial battery voltage (V) (for example, 8 (V)), the current consumption level is calculated in real time, for example. That is, current consumption level = measured battery voltage (V) / initial battery voltage (V), for example, 6/8 = 0.75. Usually less than 1.

  3, the backup time calculation unit 9 calculates the complement of the load factor calculated by the load factor calculation unit 8 (for example, 1− (40/980)). Further, the rated capacity (W) (for example, 70 (W)) of the load 6 is taken out from the storage unit 10, and the reference backup time (H) (for example, stored for the rated capacity (W) of the load 6 is stored. 3 hours) is taken out from the storage unit 10. Then, the current backup time is calculated in real time, for example, by multiplying the reference backup time (H) by the complement of the calculated load factor and the consumption level calculated by the battery consumption level calculation unit 7. That is, current backup time (H) = reference backup time (H) × complement of load factor × consumption level, for example, 3 (H) × (1− (40/980)) × (6/8) = 2.16 (H), and the current backup time (H) is shorter than the reference backup time (H).

  In step S6 of FIG. 3, the control unit 11 checks whether or not the current backup time calculated in real time by the backup time calculation unit 9 of the backup time deriving unit 3 is less than the threshold time stored in the storage unit 10. . Then, when the checked result indicates that it is less than the threshold time, the process proceeds to step S7. When the checked result indicates that it is not less than the threshold time, it is checked whether or not the current backup time is less than the threshold time until the checked result is less than the threshold time.

  In step S <b> 7 of FIG. 3, the control unit 11 outputs a charging instruction to the charging unit 4.

  In step S <b> 8 of FIG. 3, the charging unit 4 receives the charging instruction from the control unit 11 and charges the battery 2.

  When a power failure or the like occurs between Step S2 and Step S7 and no power is input from the external power supply 5 to the uninterruptible power supply 1, the control unit 11 detects this and loads the power from the battery 2 6 is instructed to supply power to the power supply switching unit 13. The power supply switching unit 13 switches the power from the battery 2 to be supplied to the load 6 in accordance with an instruction from the control unit 11. When the control unit 11 instructs the power supply switching unit 13 to supply power from the battery 2 to the load 6, the control unit 11 refers to the load factor calculated by the load factor calculating unit 8 in real time. When the load factor is “0”, the control unit 11 instructs the power supply switching unit 13 not to supply power to the load 6. The power supply switching unit 13 does not supply power to the load 6 in accordance with an instruction from the control unit 11. By doing so, when a power failure such as a power failure occurs, power is not supplied to the load 6 when there is no load 6. For this reason, since unnecessary discharge can be suppressed, battery deterioration can be prevented.

  Thus, according to the present embodiment, the current backup time of the battery with respect to the load is calculated in real time, and the calculated time is a predetermined threshold time that is required to be backed up with respect to this load. Charge the battery when below.

  For this reason, according to the present embodiment, the battery is charged when the calculated backup time becomes less than a predetermined threshold time required to be backed up, so avoid unnecessary charging. Can do. For this reason, deterioration of the battery can be prevented.

  Further, according to the present embodiment, the current backup time for the battery load is calculated in real time. For this reason, since the current backup time is calculated, the battery can be charged to satisfy the required backup time even in an environment where the power consumption of the load fluctuates greatly.

  In the above description, the storage unit 10 corresponds to the rated output capacity of the uninterruptible power supply 1, the initial battery voltage of the battery 2 mounted on the uninterruptible power supply 1, and the rated capacity (W) of the load 6. The reference backup time (H) is stored in advance. However, these data may not be stored in the storage unit 10 in advance. For example, when the power of the uninterruptible power supply 1 is turned on, the data may be input from the outside by some method. That is, it is sufficient that these data can be used after the uninterruptible power supply 1 is turned on, and the input method and the storage method need not be particular. In the above description, the rated capacity of the load 6 and the predetermined threshold time are input based on a user operation when the load 6 is connected to the uninterruptible power supply 1 and stored in the storage unit 10. I have to. However, these data do not need to be input based on the user's operation when the load 6 is connected to the uninterruptible power supply 1 and stored in the storage unit 10, for example, the power supply of the uninterruptible power supply 1. It may be input from the outside by some method after turning ON. That is, it is sufficient that these data can be used after the uninterruptible power supply 1 is turned on, and the input method and the storage method need not be particular.

DESCRIPTION OF SYMBOLS 1 Uninterruptible power supply 2 Battery 3 Backup time derivation part 4 Charging part 5 External power supply 6 Load 7 Battery consumption degree calculation part 8 Load factor calculation part 9 Backup time calculation part 10 Storage part 11 Control part 12 AC / DC conversion part 13 Power supply Switching part

Claims (7)

An uninterruptible power supply that supplies power to a load by an external power source and supplies power to the load by a battery when the external power source is not input,
The battery;
Calculate the current load factor indicating the degree of power supply to the load for the uninterruptible power supply and the degree of consumption of the battery, and at a reference backup time predetermined according to the uninterruptible power supply, A backup time deriving unit that calculates in real time a current backup time indicating a period during which the load can be backed up by the battery by multiplying the complement of the load factor and the consumption rate ;
A charging unit that charges the battery when the current backup time calculated by the backup time deriving unit becomes less than a predetermined threshold time when power is supplied to the load by the external power source; , with,
An uninterruptible power supply. A storage unit that pre-stores the rated output capacity of the uninterruptible power supply device and the initial battery voltage indicating the battery voltage when the battery at the time of shipment of the uninterruptible power supply device is fully charged;
The backup time deriving unit
A load factor calculation unit for measuring the current power consumption of the load in real time by dividing the measured power consumption by the rated output capacity stored in the storage unit;
A battery consumption level calculation unit that measures a current battery voltage and calculates the current consumption level in real time by dividing the measured battery voltage by the initial battery voltage stored in the storage unit;
The current backup time is obtained by multiplying the reference backup time stored by the storage unit by the complement of the load factor calculated by the load factor calculation unit and the consumption level calculated by the battery consumption level calculation unit. A backup time calculation unit that calculates in real time,
The uninterruptible power supply according to claim 1. A control unit that outputs a charging instruction to the charging unit when the current backup time calculated by the backup time deriving unit is less than the predetermined threshold time;
The charging unit receives the charging instruction from the control unit and charges the battery.
The uninterruptible power supply according to claim 1 or 2. When the input of the external power source is cut off, the load factor calculating unit refers to the load factor calculated in real time, and when the load factor is 0, it is determined that the load is not operating and the battery A control unit for controlling so as not to supply power to the load from
The uninterruptible power supply according to claim 2 or 3. An uninterruptible power supply method using an uninterruptible power supply that supplies power to a load by an external power source and supplies power to the load by a battery when the external power source is not input,
A current load factor indicating a supply degree of power to the load to the uninterruptible power supply and a consumption level of the battery are calculated, and the load is calculated at a reference backup time predetermined according to the uninterruptible power supply. By multiplying the complement of the rate and the consumption rate, the current backup time indicating the period during which the load can be backed up by the battery is calculated in real time,
Charging the battery when the calculated current backup time is less than a predetermined threshold time when power is supplied to the load by the external power source;
An uninterruptible power supply method. Measure the current power consumption of the load, and calculate the current load factor in real time by dividing the measured power consumption by the rated output capacity of the uninterruptible power supply,
The current battery voltage is measured, and the measured battery voltage is divided by the initial battery voltage indicating the battery voltage when the battery at the time of shipment of the uninterruptible power supply is fully charged. Calculate wear level in real time,
The current backup time is calculated in real time by multiplying the reference backup time by the complement of the calculated load factor and the calculated degree of wear.
The uninterruptible power supply method according to claim 5. When the input of the external power supply is cut off, the load factor calculated in real time is referred to. When the load factor is 0, it is determined that the load is not operating and power is not supplied from the battery to the load. To
The uninterruptible power supply method according to claim 6.

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