JP2013126331A - Electronic apparatus and battery unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce such possibility that when a battery voltage of either one of a plurality of battery units reaches a final voltage, output currents of the other battery units turn out to be excess currents, in an electronic apparatus to which power is supplied from the battery units.SOLUTION: A server 10 includes: a plurality of battery backup units 20 including a battery block 22 and a control device 21 for controlling the battery block 22; and a signal line 15 to which signal input and output terminals 28 of the battery backup units 20 are connected in parallel. The control device 21 includes means for changing the potential of the signal input and output terminals 28 to a ground potential on condition that the final voltage of the battery block 22 is detected, and means for stopping discharge from the battery block 22 on condition that change of the potential of the signal input and output terminals 28 to the ground potential is detected.

Description

  The present invention relates to an electronic device and a battery unit that supplies electric power to the electronic device.

  For example, an electronic device such as a mainframe or a server provided in an information communication facility such as an IDS (Internet Data Center) is generally provided with a backup battery unit in preparation for a power failure of a commercial AC power source. In such an electronic device, a plurality of battery units are often connected in accordance with specifications such as rated power consumption of the electronic device.

  Here, as an example of a power supply device including a plurality of batteries, a control circuit (CPU) is provided in each of a plurality of battery packs, and each control circuit is connected by a bus line so as to be capable of data communication with each other. . More specifically, in the conventional power supply device, any one of the plurality of battery packs operates as a master battery pack, and the others operate as slave battery packs. The master battery pack receives data from each slave battery pack, manages the state of charge (SOC) of all battery packs, etc., and transmits a command to each slave battery pack. The slave battery pack transmits data such as its own charge state to the master battery pack, and performs charge / discharge control according to a command transmitted from the master battery pack (see, for example, Patent Document 1).

JP 2000-294298 A

  When power is supplied from a plurality of battery units to an electronic device, it is ideal that the state of charge of the plurality of battery units decreases at the same pace, and the battery voltages of the plurality of battery units reach the end voltage at the same time. . In reality, however, the battery voltage of any one of the battery units first becomes the end voltage first due to variations in the battery characteristics of each battery unit or differences in the degree of deterioration. That is, when electric power is supplied from a plurality of battery units, it is normal that some time difference occurs between the plurality of battery units at the timing when the battery voltage becomes the end voltage.

  And from the time when the battery voltage of any one of the battery units reaches the end voltage, the discharge current of each battery unit is short, from the time when all the battery voltages of the other battery units reach the end voltage. It will increase from the normal time. Therefore, the discharge from each battery unit may temporarily become an overcurrent. In particular, when each battery unit is provided with an overcurrent protection circuit, there is a possibility that the overcurrent protection circuit detects an overcurrent and stops discharging of each battery unit. In other words, although the battery has essentially run out, it will result in an abnormal stop due to overcurrent detection. For this reason, all of the electronic devices and the plurality of battery units have to be checked each time for abnormalities or failures that cause overcurrent.

  Here, in the above prior art, when the battery voltage of any one of the slave battery packs reaches the end voltage, for example, data indicating the end voltage is transmitted from the slave battery pack to the master battery pack, and the data is received. If the master battery pack transmits the discharge stop control command to all the slave battery packs, each slave battery pack that has received the command executes the discharge stop control. However, normally, the operation time of the overcurrent protection circuit is almost shorter than the time required for transmitting and receiving data, commands, etc. between battery packs in a certain communication procedure. Therefore, it is difficult to avoid the abnormal stop due to the overcurrent detection as described above in the power supply device of the prior art.

  Further, for example, by delaying the overcurrent detection by delaying the operation of the overcurrent protection circuit by a time constant circuit or the like, it is possible to avoid the abnormal stop due to the overcurrent detection as described above. However, if the operation of the overcurrent protection circuit is delayed, there is a risk that the protection function by the original overcurrent detection may be greatly reduced, which causes a problem from the viewpoint of safety.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide an electronic device to which power is supplied from a plurality of battery units, when the battery voltage of any one of the battery units becomes a final voltage. This is to reduce the possibility that the output current of another battery unit becomes an overcurrent.

<First Aspect of the Present Invention>
A first aspect of the present invention includes a battery, a plurality of battery units including a control device for controlling the battery, and a signal line to which predetermined signal input / output terminals of the battery unit are connected in parallel, The control device includes means for changing the potential of the predetermined signal input / output terminal to a predetermined potential on the condition that the end voltage of the battery is detected, and the potential of the predetermined signal input / output terminal is the predetermined potential. An electronic device comprising: means for stopping discharge from the battery, on condition that the change is detected.

  When the battery voltage reaches the end voltage in any one of the plurality of battery units, the control unit of the battery unit changes the potential of a predetermined signal input / output terminal of the battery unit to a predetermined potential. The plurality of battery units have predetermined signal input / output terminals connected in parallel to the signal lines. Therefore, when the potential of a predetermined signal input / output terminal changes to a predetermined potential in a battery unit whose battery voltage has reached the end voltage, the potential of the signal line instantaneously becomes a predetermined potential, thereby instantaneously in all the battery units. The potential of the predetermined signal input / output terminal changes to the predetermined potential. Each control device of the plurality of battery units stops discharging from the battery on condition that it detects that the potential of the predetermined signal input / output terminal has changed to the predetermined potential. As a result, all of the plurality of battery units instantaneously almost simultaneously stop discharging.

  That is, in the electronic device according to the present invention, when the battery voltage reaches the end voltage in any one of the plurality of battery units, all the battery units are stopped at the same time instantly and almost simultaneously. Will come. Therefore, according to the first aspect of the present invention, in an electronic device to which power is supplied from a plurality of battery units, when the battery voltage of any one of the battery units becomes a final voltage, the output current of another battery unit The effect that the possibility of overcurrent may be reduced can be obtained.

<Second Aspect of the Present Invention>
According to a second aspect of the present invention, in the first aspect of the present invention described above, the control device further includes means for stopping discharge from the battery on condition that the end voltage of the battery is detected. This is an electronic device characterized by that.

  For example, when the control device that detects the end-of-battery voltage executes control to change a predetermined signal input / output terminal to a predetermined potential, if there is any abnormality or failure in the predetermined signal input / output terminal or signal line, There is a possibility that the predetermined signal input / output terminal does not change to a predetermined potential. In such a situation, the discharge from each battery unit cannot be stopped in the above-described first aspect of the present invention. For this reason, a battery whose battery voltage has reached the end voltage may continue to be discharged and become overdischarged.

  According to the second aspect of the present invention, since the control device stops discharging from the battery on condition that the end voltage of the battery is detected, the predetermined signal input / output terminal is predetermined for some reason such as abnormality or failure. Even when the potential does not change to the above-described potential, there can be obtained an operational effect that it is possible to prevent in advance a situation where the battery whose battery voltage has reached the end voltage is overdischarged.

<Third Aspect of the Present Invention>
According to a third aspect of the present invention, in the first or second aspect of the present invention described above, the control device further includes a power supply line that supplies power to the plurality of battery units. The electronic apparatus further includes means for charging the battery with DC power fed from a line.
According to such a characteristic, the effect that the battery of a battery unit can be charged, without removing a battery unit from an electronic device is acquired.

<Fourth aspect of the present invention>
A fourth aspect of the present invention includes a battery and a control device that controls the battery, and the control device detects a potential of a predetermined signal input / output terminal on condition that the end voltage of the battery is detected. And a means for stopping discharge from the battery on the condition that the potential of the predetermined signal input / output terminal has been changed to the predetermined potential. The battery unit is characterized in that.
According to the fourth aspect of the present invention, the same effect as that of the first aspect of the present invention described above can be obtained in the electronic device to which power is supplied from a plurality of battery units.

<Fifth aspect of the present invention>
According to a fifth aspect of the present invention, in the fourth aspect of the present invention described above, the control device further includes means for stopping discharge from the battery on the condition that the end voltage of the battery is detected. The battery unit is characterized by that.
According to the fifth aspect of the present invention, effects similar to those of the second aspect of the present invention described above can be obtained in an electronic device to which power is supplied from a plurality of battery units.

<Sixth aspect of the present invention>
According to a sixth aspect of the present invention, in the fourth or fifth aspect of the present invention described above, the control device further includes means for charging the battery with DC power supplied from outside. The battery unit is characterized.
According to the sixth aspect of the present invention, the same effect as the third aspect of the present invention described above can be obtained in the electronic device to which power is supplied from a plurality of battery units.

  According to the present invention, in an electronic device that is supplied with power from a plurality of battery units, when the battery voltage of any one of the battery units becomes a final voltage, the output current of another battery unit may become an overcurrent. The effect of being able to reduce is obtained.

The block diagram which illustrated the composition of the server concerning the present invention. The flowchart which illustrated the procedure of the charging / discharging control of the battery block by a power failure detection. The flowchart which illustrated the procedure of the discharge stop control in discharge control. The flowchart which illustrated the modification of the procedure of the discharge stop control in discharge control.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Server configuration>
The configuration of the server 10 according to the present invention will be described with reference to FIG.
FIG. 1 is a block diagram illustrating the configuration of a server 10 according to the present invention.

  A server 10 as an “electronic device” according to the present invention includes an arithmetic processing unit 11, a first power receiving line 12, a second power receiving line 13, a power supply line 14, a signal line 15, and a plurality of battery backup units 20. .

  The arithmetic processing device 11 is a processing device that realizes various arithmetic processing functions in the server 10.

  The first power receiving line 12 is a power line that receives DC power of a predetermined voltage from the outside. More specifically, AC power supplied from the commercial AC power supply 31 is converted into DC power of a predetermined voltage by the power converter 32 and supplied to the first power receiving line 12. The first power receiving line 12 is connected to the anode terminal of the diode D1, and the cathode terminal of the diode D1 is connected to the power supply terminal of the arithmetic processing unit 11. That is, the DC power supplied from the outside to the first power receiving line 12 is supplied to the arithmetic processing unit 11 through the diode D1.

  The second power receiving line 13 is a power line that receives DC power output from a plurality of battery backup units 20 described later. More specifically, the second power receiving line 13 is connected to the anode terminal of the diode D2, and the discharge terminals 26 of the plurality of battery backup units 20 are connected in parallel. The cathode terminal of the diode D2 is connected to the cathode terminal of the diode D1. That is, the DC power discharged from the discharge terminals 26 of the plurality of battery backup units 20 is supplied to the arithmetic processing unit 11 through the diode D2.

  The power supply line 14 is a power line that supplies a part of DC power supplied from the outside to the plurality of battery backup units 20. More specifically, the power supply line 14 is connected to the first power receiving line 12, and the charging terminals 27 of the plurality of battery backup units 20 are connected in parallel. That is, a part of the DC power supplied from the outside is used for charging each battery backup unit 20 through the charging terminals 27 of the plurality of battery backup units 20. Therefore, each battery backup unit 20 can be charged without removing the battery backup unit 20 from the server 10.

  The signal line 15 is connected to the signal input / output terminals 28 of the plurality of battery backup units 20 in parallel.

<Configuration of battery backup unit>
The configuration of the battery backup unit 20 according to the present invention will be described with continued reference to FIG.

  A battery backup unit (BBU) 20 as a “battery unit” includes a control device 21, a battery block 22, a voltage measurement unit 23, a switch circuit 24, and an overcurrent detection unit 25.

  The control device 21 includes a CPU (Central Processing Unit) 211, a field effect transistor 212, and a buffer 213. More specifically, the control device 21 is a known microcomputer control device including the CPU 211, and is a device that performs a charge / discharge control function of the battery block 22 and other various control functions by a control program executed by the CPU 211. . The field effect transistor 212 has a gate terminal connected to the signal output port of the CPU 211, a drain terminal connected to the signal input / output terminal 28, and a source terminal connected to the ground. The buffer 213 has an input terminal connected to the signal input / output terminal 28 and an output terminal connected to the signal input port of the CPU 211.

  The battery block 22 as a “battery” is configured by connecting a plurality of secondary batteries such as alkaline secondary batteries in series or in parallel, the positive terminal is connected to the switch circuit 24, and the negative terminal Is connected to ground.

  The voltage measurement unit 23 is a known measurement circuit that measures the battery voltage of the battery block 22. More specifically, the voltage measurement unit 23 converts the detected battery voltage of the battery block 22 into a digital signal and outputs the digital signal to the CPU 211.

  The switch circuit 24 includes a switch that opens and closes a discharge line from the battery block 22 to the discharge terminal 26, and a switch that opens and closes a charge line from the charge terminal 27 to the battery block 22. Each switch of the switch circuit 24 is, for example, a transistor or an electromagnetic relay, and is controlled to be opened and closed by the CPU 211.

  The overcurrent detection unit 25 detects the current flowing through the discharge line from the battery block 22 to the discharge terminal 26, and when the current value of the discharge line exceeds a preset threshold value from the rated current of the battery block 22 or the like, This is a known overcurrent protection circuit that cuts off the discharge line.

<Charge / discharge control of battery backup unit>
The charge / discharge control of the battery block 22 executed by each control device 21 of the plurality of battery backup units 20 will be described with reference to FIGS.

  FIG. 2 is a flowchart illustrating the procedure of charge / discharge control of the battery block 22 by power failure detection.

  First, it is determined whether or not the commercial AC power supply 31 is in a power failure (step S1). More specifically, a power failure detection signal of the commercial AC power supply 31 output from a power failure detection device (not shown) provided in the outside or the server 10 is input to each battery backup unit 20. The control device 21 determines whether or not the commercial AC power supply 31 is in a power failure from the power failure detection signal output by the power failure detection device.

  When the commercial AC power supply 31 is in a power failure (Yes in step S1), discharge control is executed (step S2). More specifically, when the commercial AC power supply 31 is in a power failure, the switch of the discharge line from the battery block 22 to the discharge terminal 26 is opened, and the charge line from the charge terminal 27 to the battery block 22 is closed. The switch circuit 24 is controlled. The DC power that is discharged from the battery block 22 thereby is supplied to the arithmetic processing unit 11 through the second power receiving line 13.

  On the other hand, when the commercial AC power supply 31 is not in a power failure (No in step S1), the charging control is executed (step S3). More specifically, when the commercial AC power supply 31 is not in a power failure, the switch of the discharge line from the battery block 22 to the discharge terminal 26 is closed, and the charge line from the charge terminal 27 to the battery block 22 is opened. The switch circuit 24 is controlled. As a result, the battery block 22 is charged with DC power supplied from the outside through the power supply line 14.

  FIG. 3 is a flowchart illustrating a procedure of discharge stop control during discharge control. The procedure illustrated in the flowchart is a procedure that is started and executed at the start of discharge control (step S2 in FIG. 2).

  Here, the CPU 211 sets the internal discharge stop flag (sigA) to “0” when the signal input port potential is at the low level, and the signal input port potential is at the high level. The discharge stop flag is set to “1”. At the start of the procedure, the discharge stop flag is set to “1” as an initial value. More specifically, the field effect transistor 212 is turned off. As a result, the signal input / output terminal 28 becomes high impedance and the potential of the signal input port of the CPU 211 becomes high, so that the discharge stop flag becomes “1”.

  After the discharge stop flag is set to “1” (sigA = 1) as an initial value, it is first determined whether or not the commercial AC power supply 31 is in a power failure (step S11). That is, it is determined whether or not the power failure of the commercial AC power supply 31 has been recovered during the discharge control (step S2 in FIG. 2). When the power failure of the commercial AC power supply 31 is recovered (No in Step S11), the discharge from the battery block 22 is stopped (Step S15). More specifically, when the commercial AC power supply 31 recovers during the discharge control, the switch circuit 24 is controlled so that the switch of the discharge line from the battery block 22 to the discharge terminal 26 is closed. On the other hand, if the commercial AC power supply 31 is still in a power failure (Yes in step S11), it is determined whether or not the discharge stop flag is “1” (sigA = 1) (step S12).

  When the discharge stop flag is “1” (sigA = 1) (Yes in step S12), it is determined whether or not the end voltage is detected (step S13). More specifically, it is determined whether or not the battery voltage of the battery block 22 detected by the voltage measurement unit 23 is equal to or lower than the end voltage. If the battery voltage of the battery block 22 is not lower than the end voltage (No in step S13), the process returns to step S11.

  On the other hand, when the battery voltage of the battery block 22 is equal to or lower than the end voltage (Yes in step S13), the discharge stop flag is set to “0” (sigA = 0) (step S14). More specifically, the field effect transistor 212 is turned on. As a result, the signal input / output terminal 28 becomes the ground potential (0 V), and the potential of the signal input port of the CPU 211 becomes the low level, so that the discharge stop flag becomes “0”. That is, the control device 21 changes the potential of the signal input / output terminal 28 to the ground potential (predetermined potential) on the condition that the battery voltage of the battery block 22 has reached the end voltage (Yes in Step S13) (Step S14). ).

  Returning to step S11, if a power failure is occurring (Yes in step S11), it is determined whether or not the discharge stop flag is “1” (sigA = 1) (step S12). If the discharge stop flag is “0” (sigA = 0) (No in step S12), the discharge from the battery block 22 is stopped (step S15). That is, the control device 21 stops discharging from the battery block 22 on the condition that the potential of the signal input / output terminal 28 has been changed to the ground potential (No in Step S12) (Step S15).

<Cooperation of multiple battery backup units>
The linking operation of the plurality of battery backup units 20 will be described with reference to FIGS. 1 and 3.

  As described above, when the battery voltage of the battery block 22 reaches the end voltage in any of the plurality of battery backup units 20 (Yes in step S13 in FIG. 3), the battery backup is performed by the control device 21 of the battery backup unit 20. The potential of the signal input / output terminal 28 of the unit 20 changes to the ground potential (step S14 in FIG. 3). Further, the signal input / output terminals 28 of the plurality of battery backup units 20 are respectively connected in parallel to the signal line 15 (FIG. 1). Accordingly, in the battery backup unit 20 in which the battery voltage of the battery block 22 has reached the end voltage, when the potential of the signal input / output terminal 28 changes to the ground potential, the potential of the signal line 15 instantaneously becomes the ground potential. Thereby, in all the battery backup units 20, the potential of the signal input / output terminal 28 instantaneously changes to the ground potential.

  Then, each control device 21 of the plurality of battery backup units 20 detects that the potential of the signal input / output terminal 28 has changed to the ground potential (No in step S12 in FIG. 3), from the battery block 22 Discharging is stopped (step S15 in FIG. 3). As a result, all of the plurality of battery backup units 20 stop discharging instantly and almost simultaneously.

  That is, in the server 10 according to the present invention, when the battery voltage of the battery block 22 reaches the end voltage in any one of the plurality of battery backup units 20, all the battery backup units 20 are instantaneously and almost simultaneously at that time. Will stop discharging. Thereby, when the battery voltage of any of the battery blocks 22 of the plurality of battery backup units 20 reaches the end voltage, the possibility that the output current of the other battery backup unit 20 becomes an overcurrent can be reduced.

<Other embodiments and modifications>
The present invention is not particularly limited to the embodiments described above, and it goes without saying that various modifications are possible within the scope of the invention described in the claims.

  For example, in the battery backup unit 20, when the control device 21 that detects the end voltage of the battery block 22 executes control to change the potential of the signal input / output terminal 28 to the ground potential, the signal input / output terminal 28 or the signal line 15 If there is any abnormality or failure, the signal input / output terminal 28 may not change to the ground potential. In such a situation, in the charge / discharge control (FIG. 3) of the battery block 22 by the control device 21 of the above embodiment, the discharge from each battery backup unit 20 cannot be stopped. Therefore, there is a possibility that the battery block 22 whose battery voltage has reached the end voltage will continue to be discharged and become overdischarged. For this reason, for example, the flowchart illustrated in FIG. 3 may further include a procedure for stopping the discharge from the battery block 22 on condition that the end voltage of the battery block 22 is detected. Hereinafter, a description will be given with reference to FIG.

  FIG. 4 is a flowchart illustrating a modified example of the procedure of the discharge stop control during the discharge control. The point that the discharge stop flag is set to “1” (sigA = 1) as an initial value is the same as in the above-described embodiment. Further, the contents of each procedure of steps S21 to S25 are the same as steps S11 to S15 of the flowchart shown in FIG.

  The flowchart of the modification shown in FIG. 4 is different from the flowchart shown in FIG. 3 in the flow of processing after step S24 is executed. More specifically, when the battery voltage of the battery block 22 is equal to or lower than the end voltage (Yes in Step S23), the discharge stop flag is set to “0” (sigA = 0) (Step S24), Control to stop discharging from the battery block 22 is executed as it is (step S25). Thus, by stopping the discharge from the battery block 22 on the condition that the battery voltage of the battery block 22 has become equal to or lower than the end voltage, the signal line 15 or the signal input / output terminal 28 is caused by some factor such as abnormality or failure. Even when the ground potential does not change, it is possible to prevent a situation in which the battery block 22 whose battery voltage has reached the end voltage is overdischarged.

DESCRIPTION OF SYMBOLS 10 Server 11 Processing unit 12 1st power receiving line 13 2nd power receiving line 14 Power supply line 15 Signal line 20 Battery backup unit 21 Controller 22 Battery block 23 Voltage measurement part 24 Switch circuit 25 Overcurrent detection part 26 Discharge terminal 27 Charging Terminal 28 Signal input / output terminal

Claims (6)

A plurality of battery units including a battery and a control device for controlling the battery;
A signal line to which predetermined signal input / output terminals of the battery unit are connected in parallel;
The control device is configured to change the potential of the predetermined signal input / output terminal to a predetermined potential on condition that the end voltage of the battery is detected;
Means for stopping discharge from the battery on condition that the potential of the predetermined signal input / output terminal is changed to the predetermined potential.   The electronic device according to claim 1, wherein the control device further includes means for stopping discharge from the battery on condition that an end voltage of the battery is detected. The electronic device according to claim 1, further comprising a power supply line that supplies power to the plurality of battery units,
The electronic device further includes means for charging the battery with DC power fed from the power supply line. Battery,
A control device for controlling the battery,
The control device is configured to change a potential of a predetermined signal input / output terminal to a predetermined potential on condition that the end voltage of the battery is detected;
Means for stopping discharge from the battery on condition that it has been detected that the potential of the predetermined signal input / output terminal has changed to the predetermined potential.   5. The battery unit according to claim 4, wherein the control device further includes means for stopping discharge from the battery on condition that an end voltage of the battery is detected. 6.   6. The battery unit according to claim 4, wherein the control device further includes means for charging the battery with DC power supplied from outside.

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