JP2016116334A - Power supply apparatus, electronic apparatus, and power supply control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fault tolerance of charge/discharge operation.SOLUTION: A power supply apparatus 1 includes a power storage circuit 2 and a control circuit 3. The power storage circuit 2 includes a plurality of power storage members 11a-11f and a plurality of separation circuits 13a-13f respectively corresponding to the plurality of power storage members and configured so that when a corresponding power storage member is failed, the corresponding power storage member is separated to suppress current flow into the corresponding power storage member. In the power storage circuit 2, the plurality of power storage members 11a-11f are grouped into a plurality of power storage member groups 12a-12c each including two or more power storage members connected in parallel, and the plurality of power storage member groups 12a-12c are connected in series. The control circuit 3 controls whether charge/discharge operation of the power storage circuit 2 is to be continued or not on the basis of a connection position of a failed power storage member out of the plurality of power storage members 11a-11f.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device, an electronic apparatus, and a power supply control method.

  Currently, power storage members are widely used. As the power storage member, for example, a lithium ion capacitor and a lithium ion battery are known. The power storage member can be used as a power source for a mobile phone, a PC (Personal Computer), an electric vehicle, or the like.

  For power storage members such as lithium ion capacitors and lithium ion batteries, there are cases where an upper limit value of a voltage stored during charging and a lower limit value of a voltage during discharging are determined. This is because the power storage member deteriorates when a voltage exceeding the upper limit value is stored or when a discharge is performed below the lower limit value. That is, power storage members such as lithium ion capacitors and lithium ion batteries have a characteristic that they are vulnerable to overcharge or overdischarge. Therefore, as an example of measures to be taken when overcharging or overdischarging occurs, a plurality of lithium ion batteries are connected in series, and charging is stopped when the voltage rises above a predetermined value even in one cell during charging. A technique has been proposed in which the voltage of a cell that has risen above a value is discharged, and discharge is stopped when the voltage drops to a predetermined value or less in one cell during discharge.

  In addition, as a protection circuit for the lithium ion secondary battery, two fuses connected in series so as to connect the charge / discharge side connection terminal and the positive side electrode of the secondary battery, and the wiring between the fuses and the secondary battery There has been proposed a lithium ion secondary battery system that includes a switching element arranged to connect the negative electrode of the negative electrode and a detection circuit that controls on / off of the switching element.

JP 2002-58170 A JP 2010-212166 A

  By the way, as a method of ensuring a high discharge voltage, there is a method of connecting a plurality of power storage members in series. When charging a plurality of power storage members connected in series, the voltage across the positive electrode of the positive-side power storage member and the negative electrode of the negative-side power storage member multiplies the upper limit of the voltage of the power storage member by the number of power storage members. Do not exceed the threshold value.

  Here, when a power storage member such as a lithium ion capacitor or a lithium ion battery is used, the voltage stored in each of the plurality of power storage members may not be equal due to differences in the degree of spontaneous discharge or internal deterioration. When charging is performed in a state where the voltages are not uniform, the voltage at both ends does not exceed the threshold value, but only a part of the power storage members may be overcharged. Similarly, in the case of discharging as well as in the case of discharging, if discharging is performed in a state where the voltages are unequal, the voltage at both ends does not become lower than the lower threshold, but only a part of the power storage members are overdischarged. It may become.

  In this way, if overcharging or overdischarging is repeated, deterioration of the power storage member proceeds, and the probability of failure of the power storage member increases. When a plurality of power storage members are connected in series, if even one power storage member fails, there is a problem that charging / discharging using the plurality of power storage members cannot be performed.

  In one aspect, an object of the present invention is to provide a power supply device, an electronic apparatus, and a power supply control method with improved fault tolerance of charge / discharge operations.

  In one aspect, a power supply device that performs charging and discharging using a plurality of power storage members is provided. This power supply device has a power storage circuit and a control circuit. The power storage circuit is associated with each of the plurality of power storage members and the plurality of power storage members, and when the corresponding power storage member fails, a plurality of separation circuits that separate the power storage members so that no current flows through the power storage member Have Further, in the power storage circuit, the plurality of power storage members are grouped into a plurality of power storage member groups each having two or more power storage members connected in parallel, and the plurality of power storage member groups are connected in series. The control circuit controls whether to continue the charge / discharge operation of the power storage circuit based on the connection position of the failed power storage member among the plurality of power storage members.

  In one aspect, an electronic apparatus including a power supply device that performs charging and discharging using a plurality of power storage members is provided. The power supply device includes a power storage circuit and a control circuit. The power storage circuit is associated with each of the plurality of power storage members and the plurality of power storage members, and when the corresponding power storage member fails, a plurality of separation circuits that separate the power storage members so that no current flows through the power storage member Have Further, in the power storage circuit, the plurality of power storage members are grouped into a plurality of power storage member groups each having two or more power storage members connected in parallel, and the plurality of power storage member groups are connected in series. The control circuit controls whether to continue the charge / discharge operation of the power storage circuit based on the connection position of the failed power storage member among the plurality of power storage members.

  In one aspect, a power supply control method for a power supply device that charges and discharges a power storage circuit having a plurality of power storage members is provided. In this power supply control method, a plurality of power storage members are grouped into a plurality of power storage member groups each having two or more power storage members connected in parallel, and a plurality of power storage member groups are connected in series. When at least one of the plurality of disconnecting circuits detects a failure of the corresponding power storage member in a state where the plurality of disconnection circuits associated with each of the power storage members is disposed, current does not flow to the power storage member. The power storage member is separated. Moreover, this power supply control method controls whether the control circuit provided in the power supply device continues the charge / discharge operation of the power storage circuit based on the connection position of the failed power storage member among the plurality of power storage members.

  In one aspect, the fault tolerance of the charge / discharge operation can be enhanced.

It is a figure which shows the structural example and operation example of the power supply device of 1st Embodiment. It is a comparative example at the time of connecting and charging a some electrical storage member in series. It is a comparative example at the time of discharging by connecting a plurality of electrical storage members in series. 3 is a diagram illustrating an example of hardware of a storage device according to a second embodiment. FIG. It is a figure which shows the hardware example of a power supply circuit. It is a figure which shows the internal structural example of a LIC unit. It is a figure which shows the connection state of LIC at the time of charge and discharge. It is a figure which shows the specific example in case the failure has generate | occur | produced in LIC. It is a flowchart which shows the process example (the 1) of a controller. It is a flowchart which shows the process example (the 2) of a controller. It is a flowchart which shows the process example (the 3) of a controller.

Hereinafter, the present embodiment will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a diagram illustrating a configuration example and an operation example of the power supply device according to the first embodiment. The power supply device 1 is a device that performs charge / discharge using the power storage members 11a to 11f. The power storage members 11a to 11f are members that can store electric charges and can be charged by an external charging voltage. The storage members 11a to 11f are, for example, lithium ion capacitors. Further, the storage members 11a to 11f may be members (for example, lithium ion batteries) having the same characteristics as the lithium ion capacitor.

  The power supply device 1 includes a power storage circuit 2 including power storage members 11 a to 11 f and a control circuit 3. In the power storage circuit 2, the power storage members 11a to 11f are grouped into power storage member groups 12a to 12c each having two or more power storage members connected in parallel. In the example of FIG. 1, the power storage member group 12a includes power storage members 11a and 11b connected in parallel, the power storage member group 12b includes power storage members 11c and 11d connected in parallel, and the power storage member group 12c includes: Power storage members 11e and 11f connected in parallel are included. And the electrical storage member groups 12a-12c are connected in series.

  The upper connection portion of the power storage members 11a and 11b in FIG. 1 forms the positive electrode of the power storage circuit 2, and the lower connection portion of the power storage members 11e and 11f in FIG. 1 forms the negative electrode of the power storage circuit 2. To do. Therefore, when the power storage circuit 2 is charged, the charging voltage from the charging circuit is applied to the upper connection portion of the power storage members 11a and 11b. Further, when the power storage circuit 2 is discharged, a load is connected to the connection portion on the upper side of the power storage members 11a and 11b.

  The power storage circuit 2 can output a discharge voltage three times that in the case of a single power storage member to the load due to the configuration in which the power storage members are connected in series in three stages as described above. Note that the number of power storage member groups connected in series in the power storage circuit 2 can be any number of 2 or more depending on the required discharge voltage. Further, the number of power storage members connected in parallel in each power storage member group can be any number of 2 or more.

  In addition, the power storage circuit 2 includes disconnect circuits 13a to 13f. The separation circuits 13 a to 13 f are associated with the power storage members in the power storage circuit 2 on a one-to-one basis. Each of the disconnection circuits 13a to 13f disconnects the power storage member from the power storage circuit 2 so that no current flows through the power storage member when the corresponding power storage member fails.

  In the example of FIG. 1, disconnect circuits 13a, 13b, 13c, 13d, 13e, and 13f are connected to the positive electrodes of the power storage members 11a, 11b, 11c, 11d, 11e, and 11f, respectively. When the power storage members 11a to 11f are short-circuited at the time of failure, as the disconnection circuits 13a to 13f, a circuit that opens the positive power supply line of the corresponding power storage member when a current of a predetermined value or more flows is used. it can. Such disconnection circuits 13a to 13f include fuses. Note that the disconnect circuits 13a, 13b, 13c, 13d, 13e, and 13f may be inserted into the negative power supply lines of the corresponding power storage members.

  Further, for example, the disconnecting circuits 13a to 13f may include a switch that opens the power line on the positive electrode side or the negative electrode side of the corresponding power storage member instead of the fuse. In this case, for example, when the value of the current flowing through a certain power storage member becomes equal to or greater than a predetermined value by the processing of the control circuit 3, the switch corresponding to the power storage member may be opened.

  The control circuit 3 controls whether the charging / discharging operation of the power storage circuit 2 is continued based on the connection position of the failed power storage member among the power storage members 11a to 11f. For example, the control circuit 3 continues the charge / discharge operation of the power storage circuit 2 when all of the power storage member groups 12a to 12c include one or more power storage members that do not fail. Further, the control circuit 3 stops the charge / discharge operation of the power storage circuit 2 when all power storage members included in at least one of the power storage member groups 12a to 12c have failed.

  Here, an example of a case where a plurality of power storage members are connected in series to the power supply device will be described with reference to FIGS. FIG. 2 is a comparative example in which a plurality of power storage members are connected in series and charged.

  FIG. 2 shows a state in which the power storage members 5a, 5b, and 5c are connected in series in the power supply device. If there is no variation in the characteristics of the power storage members 5a, 5b, and 5c, the voltage is uniformly accumulated in each of the power storage members 5a, 5b, and 5c. However, in the example on the left side of FIG. 2, a voltage of 2.375 V is stored in the power storage members 5 a and 5 b, while a voltage of 2.75 V is stored in the power storage member 5 c. This is due to a difference in natural discharge or internal deterioration for each power storage member.

  When charging, the power supply device is configured so that the voltage between both ends of the positive electrode of the power storage member 5a and the negative electrode of the power storage member 5c is the upper limit value of the voltage of the power storage member (for example, 3.8V). Control is performed so as not to exceed a value obtained by multiplying (11.4V = 3.8V × 3). As shown in FIG. 2, when charging is performed in a state where the voltages are uneven, only the power storage member 5c is overcharged even though the voltage across both ends (11.078V) does not exceed 11.4V. There is.

  FIG. 3 is a comparative example when a plurality of power storage members are connected in series and discharged. Similarly to charging, during discharging, if the characteristics of the power storage members 5a, 5b, 5c are not varied, the voltages of the power storage members 5a, 5b, 5c are equal. However, in the example on the left side of FIG. 3, the power storage members 5a and 5b both store a voltage of 3.69V, while the power storage member 5c stores a voltage of 3.42V. This is due to a difference in natural discharge or internal deterioration for each power storage member.

  In the case of discharging, the power supply device has a voltage (6.6 V = 2.2 V × 3) obtained by multiplying the lower end value (for example, 2.2 V) of the voltage of the power storage member by the number of power storage members (three). Control not to fall below. As shown in FIG. 3, when discharging in a state where the voltages are uneven, only the power storage member 5c is over-discharged even though the voltage across both ends (6.6V) does not fall below 6.6V. There is.

  2 and 3, when a plurality of storage members are connected in series and controlled so as to prevent overcharge and overdischarge based on the voltage at both ends, there is a difference due to variations in characteristics of each storage member. There is a possibility that the overcharge and overdischarge of the storage member of the part will be repeated. Thus, about the storage member in which overcharge and overdischarge were repeated, deterioration progresses and the possibility of failure increases. When one of the storage members connected in series as shown in FIGS. 2 and 3 fails, charging and discharging cannot be performed. For example, when a failed storage member is short-circuited, a desired discharge voltage cannot be obtained as a whole, and correct charge / discharge operation cannot be performed.

On the other hand, according to the power supply device 1 shown in FIG. 1, there is a possibility that the charge / discharge operation can be continued even when a failure occurs in some of the power storage members. Hereinafter, the description will be returned to FIG.
For example, assume that the power storage member 11c has failed as in state 1 in the lower left of FIG. In this case, the storage member 11c is disconnected by the disconnection circuit 13c. As a result, the state in which the positive electrode and the negative electrode of the power storage member 11d connected in parallel with the power storage member 11c are short-circuited is eliminated, and a current flows through the power storage member 11d.

  In this state, the charge / discharge operation of the power storage circuit 2 can be continued while maintaining the state where the power storage member 11a or the power storage member 11b, the power storage member 11d, and the power storage member 11e or the power storage member 11f are connected in series. Therefore, when it is detected that only the power storage member 11c has failed, the control circuit 3 determines that the charge / discharge operation of the power storage circuit 2 can be continued, and continues the charge / discharge operation. As a result, the charge / discharge operation can be continued despite the presence of a faulty power storage circuit. Moreover, at the time of discharge, the discharge voltage for three electrical storage members can be obtained.

  On the other hand, it is assumed that the power storage member 11d further fails from the state 1 as in the state 2 in the lower right of FIG. In this case, the storage member 11d is disconnected by the disconnection circuit 13d. In this state, the power storage member group 12a and the power storage member group 12c are not connected, and the charge / discharge operation of the power storage circuit 2 cannot be continued. Therefore, when it is detected that the power storage members 11c and 11d have failed, the control circuit 3 determines that the charge / discharge operation of the power storage circuit 2 cannot be continued and stops the charge / discharge operation.

  The control circuit 3 determines whether or not to continue the charge / discharge operation of the power storage circuit 2 based on the following determination condition, for example. The control circuit 3 continues the charge / discharge operation when all of the power storage member groups 12a to 12c include one or more power storage members that are not in failure. The control circuit 3 stops the charge / discharge operation when all the power storage members included in at least one of the power storage member groups 12a to 12c have failed.

  According to the first embodiment described above, there is a possibility that the charge / discharge operation of the power storage circuit 2 can be continued even when a failure of the power storage member occurs. Thereby, the fault tolerance of charging / discharging operation | movement can be improved and the reliability of the power supply device 1 can be improved.

[Second Embodiment]
Next, as a second embodiment, an example in which the power supply device 1 according to the first embodiment is applied to a storage device will be described. In addition, the power supply device in the following storage device has a function of preventing variation in the voltage accumulated in each power storage member during charging in addition to the function of disconnecting the failed power storage member and continuing the charge / discharge operation. .

  In the second embodiment, a lithium ion capacitor is used as the power storage member. However, for example, a lithium ion battery can be used. Hereinafter, each lithium ion capacitor is abbreviated as “LIC (Lithium-Ion Capacitor)”.

  FIG. 4 is a diagram illustrating a hardware example of the storage apparatus according to the second embodiment. The storage apparatus 100 includes a CM (Controller Module) 101, HDDs (Hard Disk Drives) 102 and 102a, and LEDs (Light Emitting Diodes) 103a and 103b. Note that the storage apparatus 100 may have a plurality of CMs, or may have one or three or more HDDs. A host device 300 is connected to the CM 101. For example, communication is performed between the CM 101 and the host apparatus 300 through a SAN (Storage Area Network).

  The CM 101 includes a processor 104, a RAM (Random Access Memory) 105, an SSD (Solid State Drive) 106, a DI (Drive Interface) 107, and a CA (Channel Adapter) 108. Each unit is connected to the bus. In addition, the CM 101 includes a power supply circuit 200.

  The processor 104 controls information processing of the CM 101. The processor 104 is, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA). The processor 104 may be a multiprocessor. The processor 104 may be a combination of two or more elements such as a CPU, a DSP, an ASIC, and an FPGA.

  A RAM 105 is a main storage device of the CM 101. The RAM 105 temporarily stores at least part of an OS (Operating System) program and application programs to be executed by the processor 104. The RAM 105 stores various data used for processing by the processor 104.

  The SSD 106 is an auxiliary storage device of the CM 101. The SSD 106 is a nonvolatile semiconductor memory. The SSD 106 stores an OS program, application programs, and various data. Note that the CM 101 may include an HDD instead of the SSD 106 as an auxiliary storage device.

The DI 107 is an interface for communicating with the HDDs 102 and 102a. The CA 108 is an interface for communicating with the host device 300.
The power supply circuit 200 generates a drive voltage based on a DC (Direct Current) voltage input from an external power supply external to the storage apparatus 100, and supplies the drive voltage to each part in the CM 101. In addition, the power supply circuit 200 has a function of supplying a drive voltage to the RAM 105 using the LIC in order to prevent the cache data stored in the RAM 105 from being lost during a power failure. In addition, the power supply circuit 200 charges the LIC using an external DC power supply when there is no power failure.

  The LEDs 103a and 103b are turned on when a failure occurs in the LIC included in the power supply circuit 200. As will be described later, when a failure has occurred in some LICs in the power supply circuit 200 but the charge / discharge operation can be continued using other LICs, the LED 103a is turned on. Further, the LED 103b is turned on when the charge / discharge operation cannot be continued due to a failure of the LIC in the power supply circuit 200. In addition, notification of such a failure state may be performed, for example, by display on a liquid crystal display, or may be performed by audio output. The two states may be distinguished by, for example, blinking and lighting of one LED.

  FIG. 5 is a diagram illustrating a hardware example of the power supply circuit. Note that FIG. 5 shows only a configuration related to power supply to the RAM 105 among the configurations of the power supply circuit 200. The power supply circuit 200 includes a matching circuit 201, diodes 202 and 203, a controller 210, a power supply circuit 220, a charging circuit 230, a discharging FET (Field Effect Transistor) 240, and an LIC unit 250.

  The controller 210 includes a CPU 211, a RAM 212, a flash memory 213, a voltage monitor 214, and an interface (I / F) circuit 215. The controller 210 is an example of the control circuit 3 in FIG.

The CPU 211 controls the entire controller 210. The CPU 211 may be a multiprocessor.
The RAM 212 is a main storage device of the controller 210. The RAM 212 temporarily stores at least some of the plurality of application programs. The RAM 212 stores various data used for processing by the CPU 211.

  The flash memory 213 is an auxiliary storage device of the controller 210. The flash memory 213 is a nonvolatile semiconductor memory. The flash memory 213 stores application programs and various data.

The voltage monitor 214 detects the voltage value of the LIC included in the LIC unit 250.
The interface circuit 215 outputs a control signal to each of the charging circuit 230, the discharging FET 240, the LIC unit 250, and the LEDs 103a and 103b based on an instruction from the CPU 211.

  The matching circuit 201 outputs the input voltage when the DC voltage from the external power supply is input, and inputs the input voltage from the LIC unit 250 via the discharging FET 240 when the DC voltage is not input. Output voltage. The output voltage of the matching circuit 201 is supplied to the RAM 105 and the charging circuit 230. Note that the output voltage from the matching circuit 201 may be converted into the drive voltage of the RAM 105 by a voltage conversion circuit (not shown), and the converted drive voltage may be supplied to the RAM 105.

  The diode 202 limits the direction of the current flowing in the wiring between the matching circuit 201 and the power supply circuit 220 to the direction from the matching circuit 201 to the power supply circuit 220. The diode 203 restricts the direction of the current flowing in the wiring between the discharging FET 240 and the power supply circuit 220 to the direction from the discharging FET 240 to the power supply circuit 220.

  The power supply circuit 220 is a circuit that supplies a constant drive voltage to the controller 210. When a power failure has not occurred, the power supply circuit 220 converts the voltage supplied from the external power supply via the matching circuit 201 into a drive voltage and supplies it to the controller 210. On the other hand, when a power failure occurs, the power supply circuit 220 converts the voltage supplied from the LIC unit 250 via the discharge FET 240 into a drive voltage and supplies it to the controller 210.

  When the charging circuit 230 receives an instruction to start charging the LIC unit 250 from the controller 210, the charging circuit 230 converts the voltage supplied from the external power source into a predetermined voltage for charging and supplies the voltage to the LIC unit 250.

  The discharging FET 240 is a control element for discharging the voltage accumulated in the LIC unit 250. For example, the discharging FET 240 is a MOS (Metal-Oxide-Semiconductor) -FET. The discharging FET 240 opens and closes according to an instruction from the controller 210 and controls energization and interruption of the current output from the LIC unit 250 to the butt circuit 201 and the diode 203. The discharging FET 240 is controlled to be turned off (blocked state) during charging and to be turned on (energized state) at times other than charging.

  The LIC unit 250 is a circuit for storing a voltage to be supplied to the RAM 105 at the time of a power failure, and has a plurality of LICs. The LIC unit 250 is an example of the power storage circuit 2 in FIG.

  FIG. 6 is a diagram illustrating an internal configuration example of the LIC unit. FIG. 6 also shows the connection relationship between the LIC unit, the charging circuit 230, the discharging FET 240, and the controller 210.

The LIC unit 250 includes cells 251 to 253, fuses 254a to 254f, and switching circuits 255a to 255f.
In the second embodiment, two LICs connected in parallel are called “cells”. The cell 251 includes LICs 251a and 251b. The cell 252 includes LICs 252a and 252b. The cell 253 includes LICs 253a and 253b. The connection point of each positive side wiring of the LICs 251a and 251b is connected to the charging circuit 230 and the discharging FET 240, and the connection point of the negative side wiring of the LICs 253a and 253b is connected to the ground (GND).

  The fuses 254a, 254b, 254c, 254d, 254e, and 254f are arranged in association with the LICs 251a, 251b, 252a, 252b, 253a, and 253b, respectively. The fuses 254a to 254f are examples of the disconnect circuits 13a to 13f in FIG.

  The fuses 254a to 254f are inserted into the wiring on the positive side of the corresponding LIC, and burn out when a current of a predetermined value or more flows through the wiring, thereby opening the wiring. Accordingly, the fuses 254a to 254f prevent a current from flowing through the LIC when the corresponding LIC fails and is short-circuited. For example, when the LIC 251a fails and is short-circuited, the fuse 254a is cut to prevent current from flowing through the failed LIC 251a. The fuses 254a to 254f may be inserted into the wiring on the negative electrode side of the corresponding LIC.

  The switching circuits 255a to 255f are switching elements such as MOS-FETs, and switch energization and interruption of the inserted wirings based on instructions from the controller 210. The switching circuit 255a is arranged between the connection point of each negative electrode side wiring of the LICs 251a and 251b and the connection point of each positive electrode side wiring of the LICs 252a and 252b. The switching circuit 255b is arranged between the connection point of each negative electrode side wiring of the LICs 252a and 252b and the connection point of each positive electrode side wiring of the LICs 253a and 253b.

  The switching circuit 255c is disposed between the connection point of each negative electrode side wiring of the LICs 251a and 251b and the connection point of each negative electrode side wiring of the LICs 252a and 252b. The switching circuit 255d is arranged between the connection point of each negative electrode side wiring of the LICs 252a and 252b and the connection point of each negative electrode side wiring of the LICs 253a and 253b.

  The switching circuit 255e is disposed between the connection point of each positive electrode side wiring of the LICs 251a and 251b and the connection point of each positive electrode side wiring of the LICs 252a and 252b. The switching circuit 255f is arranged between the connection point of each positive electrode side wiring of the LICs 252a and 252b and the connection point of each positive electrode side wiring of the LICs 253a and 253b.

  The controller 210 controls the energization / cutoff states of the switching circuits 255a to 255f, thereby switching between a connection state in which the cells 251 to 253 are connected in series and a connection state in which the cells 251 to 253 are connected in parallel. It is done.

  The voltage monitor 214 detects the voltage value on the positive side of each of the LICs 251a, 251b, 252a, 252b, 253a, 253b. The CPU 211 of the controller 210 can calculate the voltage accumulated in each of the LICs 251a, 251b, 252a, 252b, 253a, and 253b based on the voltage value detected by the voltage monitor 214.

FIG. 7 is a diagram illustrating a connection state of the LIC during charging and discharging. In FIG. 7, the fuses 254a to 254f and the switching circuits 255a to 255f are not shown.
The upper part of FIG. 7 shows the connection state of the LIC during charging. Under the control of the controller 210, the switching circuits 255a and 255b are turned off (shut off state), and the switching circuits 255c to 255f are turned on (energized state), so that the cells 251 to 253 are connected in series. In this state, the number of LICs in the serial direction is one, and the six LICs 251a, 251b, 252a, 252b, 253a, and 253b are connected in parallel. "6 parallel" may be described.

  On the other hand, the lower part of FIG. 7 shows the connection state of the LIC during discharge. Under the control of the controller 210, the switching circuits 255a and 255b are turned on and the switching circuits 255c to 255f are turned off, so that the cells 251 to 253 are connected in series. In this state, cells in which two LICs are connected in parallel are connected in three stages in series, and thus this connection state may be referred to as “3 series and two parallel” in the following. In the 3 series 2 parallel state, a discharge voltage three times the discharge voltage of one LIC is obtained.

  Here, in the state of 3 series 2 parallel, when charging is performed so that the voltage between both ends (the voltage between the positive side of the cell 251 and the negative side of the cell 253) does not exceed a predetermined threshold, Only some LICs may be overcharged. For example, it is assumed that charging is started in a state where the voltages accumulated in the LICs 251a, 251b, 252a, 252b, 253a, and 253b are unequal due to variations in characteristics such as how natural discharge proceeds and the state of internal deterioration. Here, if the LIC 251a is higher than the other LICs at the start of charging, even if the voltage at both ends does not exceed the threshold value, only the LIC 251a may exceed the predetermined upper limit voltage and become overcharged. There is.

  On the other hand, the controller 210 makes the connection state of the LIC 1 series 6 parallel when the charging of the LIC unit 250 is started. In this state, the same voltage is applied from the charging circuit 230 to all the LICs 251a, 251b, 252a, 252b, 253a, and 253b. For this reason, even when there is a variation in characteristics among the LICs 251a, 251b, 252a, 252b, 253a, 253b, a uniform voltage is accumulated in all the LICs 251a, 251b, 252a, 252b, 253a, 253b. Therefore, even if the charging operation is controlled so that the voltage across the LIC unit 250 does not exceed the predetermined threshold value, it is possible to prevent the occurrence of a situation in which only some LICs are overcharged. Deterioration can be suppressed and the probability of failure occurrence can be reduced.

  On the other hand, when charging of the LIC unit 250 is completed, the controller 210 sets the connection state of the LICs to 3 series and 2 in parallel. As a result, a discharge voltage three times the discharge voltage generated by one LIC can be supplied to the RAM 105 via the discharge FET 240.

  FIG. 8 is a diagram illustrating a specific example when a failure has occurred in the LIC. FIG. 8A shows a case where the LIC 252a fails during discharging. When the LIC 252a fails and is short-circuited, a large current temporarily flows to the fuse 254c, and the fuse 254c is cut. Thereby, the state where both ends of the LIC 252b connected in parallel to the failed LIC 252a are short-circuited is avoided, and the state where the LICs are connected in three stages in series is maintained. Therefore, the discharge operation can be continued while maintaining the discharge voltage.

  The controller 210 determines that the LIC 252a has failed by detecting that the voltage across the LIC 252a has suddenly decreased. At this time, the controller 210 determines whether or not all of the LICs 252a and 252b included in the cell 252 are out of order. The controller 210 determines that the LIC 252b has not failed. Since the LIC 252b has not failed, the controller 210 determines that the discharge operation using the LICs 251a, 251b, 252b, 253a, 253b can be continued. In this case, the controller 210 keeps the discharging FET 240 open and continues the discharging operation.

  In this way, by setting the connection state by a combination of series and parallel at the time of discharge, the discharge operation can be continued even if some LICs included in the cell have failed. Therefore, the life of the function as a backup power source of the RAM 105 by the LIC unit 250 can be extended, and the reliability of the operation can be improved.

  On the other hand, FIG. 8B shows a case where the LIC 252b further fails from the state of FIG. When the LIC 252b fails and is short-circuited, the fuse 254d is cut. The controller 210 determines that the LIC 252b has failed by detecting that the voltage across the LIC 252b has suddenly decreased. At this time, the controller 210 determines that all of the LICs 252a and 252b included in the cell 252 have failed. The controller 210 determines that the discharge operation cannot be continued because all of the LICs 252a and 252b included in the cell 252 have failed, and closes the discharge FET 240 to stop the discharge operation.

  In the second embodiment, a configuration in which cells including two LICs connected in parallel can be connected in three stages in series is not limited as long as the number of LICs in the cell is plural. Further, the number of cells that can be connected in series is not limited as long as it is plural.

  FIG. 8 shows a case where a failure of the LIC occurs in a state where the LICs are connected in 3 series and 2 parallels. However, for example, even when the LIC unit 250 is being charged and a LIC failure occurs when one LIC is connected in parallel in one series, the controller 210 has one LIC that has not failed in all cells. If there is more than one, the charging circuit 230 continues the charging operation.

  By the way, two LEDs 103 a and 103 b are connected to the controller 210. As shown in the example of FIG. 8A, the controller 210 turns on the LED 103a when some of the LICs in the LIC unit 250 have failed but the charge / discharge operation can be continued. On the other hand, as shown in FIG. 8B, the controller 210 turns on the LED 103b when the charge / discharge operation cannot be continued due to the failure of the LIC.

  As a result, the controller 210 can notify the user of a case where the charge / discharge operation can be continued even though some of the LICs have failed, and a case where the charge / discharge operation cannot be continued due to a failure of the LIC. The user can distinguish and recognize these states. In particular, by notifying the former state, the user can recognize the failure of the LIC and replace the failed LIC before the charge / discharge operation cannot be continued.

  Next, processing of the controller 210 will be described using a flowchart. 9 to 11 are flowcharts illustrating examples of processing performed by the controller. Hereinafter, the processes illustrated in FIGS. 9 to 11 will be described in order of step number. 9 is started when the supply of DC power from the external power supply to the power supply circuit 200 is started and the controller 210 is activated.

(S11) The controller 210 turns off the discharging FET 240. Thereby, the discharge of the LIC unit 250 is prevented.
(S12) The controller 210 turns off the switching circuits 255a and 255b, turns on the switching circuits 255c to 255f, and switches the connection state of the LICs to the 1-series 6-parallel state.

  (S13) The controller 210 instructs the charging circuit 230 to start charging. As a result, the output voltage from the charging circuit 230 is applied to the LICs 251a, 251b, 252a, 252b, 253a, 253b.

The determination processes in the next steps S14 and S15 are repeatedly executed at regular intervals.
(S14) Based on the voltage detected by the voltage monitor 214, the controller 210 determines whether the both-ends voltage has exceeded a predetermined upper limit threshold. The both-end voltage mentioned here is a voltage between the positive electrode and the negative electrode of the cells 251 to 253 connected in parallel. The upper threshold value is, for example, 3.8V. If the both-end voltage is equal to or lower than the upper limit threshold, the process proceeds to step S15. When the both-ends voltage exceeds the upper limit threshold, the process proceeds to step S21 in FIG.

  (S15) The controller 210 determines whether a LIC failure has occurred. The failure of the LIC is detected when the voltage between the two poles of the LIC suddenly drops (or becomes 0V). If a LIC failure has occurred, the process proceeds to step S16. If no LIC failure has occurred, the process proceeds to step S14.

(S16) The controller 210 turns on the LED 103a to alarm that a LIC failure has occurred and the charge / discharge operation is continued.
(S17) The controller 210 determines whether there is a cell in which all the LICs have failed. If there is a cell in which all LICs have failed, the process proceeds to step S18. If there is no cell in which all LICs have failed, the process proceeds to step S14.

  (S18) The controller 210 instructs the charging circuit 230 to stop charging. In addition, the controller 210 keeps the discharging FET 240 off. Thereby, the charging / discharging operation of the LIC unit 250 is stopped.

(S19) The controller 210 turns on the LED 103b and alarms that the charge / discharge operation has been stopped due to a failure of the LIC. Then, the process ends.
(S21) The controller 210 instructs the charging circuit 230 to stop charging. Thereby, the charging operation of the LIC unit 250 is stopped.

  (S22) The controller 210 turns on the switching circuits 255a and 255b, turns off the switching circuits 255c to 255f, and switches the connection state of the LICs to the 3 series 2 parallel state.

(S23) The controller 210 turns on the discharging FET 240. As a result, when a power failure occurs, the battery can be discharged at any time (standby state).
(S24) The controller 210 determines whether there is a DC voltage input from the external power supply at regular intervals. When the DC voltage input from the external power supply is lost (that is, when a power failure occurs), the process proceeds to step S31 in FIG. In this case, the LIC unit 250 transitions to a discharging state, and power supply from the LIC unit 250 to the RAM 105 is started.

The determination processes in the next steps S31 to S33 are repeatedly executed at regular intervals.
(S31) The controller 210 determines whether or not there is a DC voltage input from the external power supply. If no DC voltage is input from the external power supply, the process proceeds to step S32. When the input of the DC voltage from the external power source is resumed, the process proceeds to step S11 in FIG.

  (S32) Based on the voltage detected by the voltage monitor 214, the controller 210 determines whether the both-ends voltage has fallen below a predetermined lower threshold. The voltage between both ends here is a voltage between the positive electrode of the cell 251 and the negative electrode of the cell 253 among the cells 251 to 253 connected in series. The lower threshold is, for example, 2.2V. If the both-end voltage is equal to or greater than the lower limit threshold, the process proceeds to step S33. If the both-ends voltage is below the lower threshold, the process proceeds to step S37. In the latter case, the discharge operation is stopped.

  (S33) The controller 210 determines whether a LIC failure has occurred. If a LIC failure has occurred, the process proceeds to step S34. If no LIC failure has occurred, the process proceeds to step S31.

(S34) The controller 210 turns on the LED 103a to alarm that a LIC failure has occurred and the charge / discharge operation is continued.
(S35) The controller 210 determines whether there is a cell in which all the LICs have failed. If there is a cell in which all the LICs have failed, the process proceeds to step S36. If there is no cell in which all LICs have failed, the process proceeds to step S31.

(S36) The controller 210 turns on the LED 103b and alarms that the charge / discharge operation has been stopped due to a failure of the LIC.
(S37) The controller 210 turns off the discharging FET 240 and stops the discharging operation. Then, the process ends.

  In FIG. 10, the controller 210 does not perform any determination processing in the standby state, but may perform the following determination processing. For example, the controller 210 may periodically perform the determination process in step S32 in FIG. 11 in the standby state, and may proceed to step S37 when determining that the both-ends voltage has fallen below the lower limit threshold value. Further, the controller 210 may periodically perform the determination process in step S33 in the standby state. In this case, when the controller 210 detects a failed LIC, the controller 210 performs the processes of steps S34 and S35. If it is determined in step S35 that there is a cell in which all the LICs are defective, the process proceeds to step S36. .

  In the second embodiment, the power supply circuit 200 is provided to supply a voltage to the RAM 105. However, in order to supply a voltage to any component included in an electronic apparatus such as an information processing apparatus such as a PC. A power supply circuit 200 may be provided.

  Each of the above embodiments can be implemented by combining a plurality of embodiments within a consistent range.

DESCRIPTION OF SYMBOLS 1 Power supply device 2 Power storage circuit 3 Control circuit 11a-11f Power storage member 12a-12c Power storage member group 13a-13f Disconnect circuit

Claims (6)

In a power supply device that charges and discharges using a plurality of power storage members,
The plurality of power storage members, and a plurality of separation circuits that are associated with each of the plurality of power storage members and that separate the power storage members so that no current flows through the power storage member when the corresponding power storage member fails. The power storage circuit, wherein the plurality of power storage members are grouped into a plurality of power storage member groups each having two or more power storage members connected in parallel, and the plurality of power storage member groups are connected in series. Circuit,
A control circuit that controls whether to continue the charge / discharge operation of the power storage circuit based on the connection position of the power storage member that has failed among the power storage members;
A power supply unit having A switching circuit that switches a connection state of the plurality of power storage members between a first state in which the plurality of power storage member groups are connected in series and a second state in which the plurality of power storage member groups are connected in parallel; In addition,
The control circuit controls the switching circuit to switch the connection state to the second state when charging of the power storage circuit starts and to switch the connection state to the first state when charging of the power storage circuit is completed. ,
The power supply device according to claim 1. The control circuit stops the charge / discharge operation and notifies a notification device connected to the power supply device when all of the power storage members included in at least one of the plurality of power storage member groups have failed. To output information,
The power supply device according to claim 1 or 2. The control circuit includes:
When all of the plurality of power storage member groups include one or more non-failed power storage members, the charge / discharge operation is continued, and first notification information is sent to a notification device connected to the power supply device. Output
When all power storage members included in at least one of the plurality of power storage member groups have failed, the charging / discharging operation is stopped, and the notification device is configured to output second notification information,
The power supply device according to claim 1 or 2. In an electronic device including a power supply device that performs charging and discharging using a plurality of power storage members,
The power supply device
The plurality of power storage members, and a plurality of separation circuits that are associated with each of the plurality of power storage members and that separate the power storage members so that no current flows through the power storage member when the corresponding power storage member fails. The power storage circuit, wherein the plurality of power storage members are grouped into a plurality of power storage member groups each having two or more power storage members connected in parallel, and the plurality of power storage member groups are connected in series. Circuit,
A control circuit that controls whether to continue the charge / discharge operation of the power storage circuit based on the connection position of the power storage member that has failed among the power storage members;
Having an electronic device. In a power supply control method in a power supply device that charges and discharges a power storage circuit having a plurality of power storage members,
The plurality of power storage members are grouped into a plurality of power storage member groups each having two or more power storage members connected in parallel, and the plurality of power storage member groups are connected in series, and the plurality of power storage members When at least one of the plurality of disconnecting circuits detects a failure of the corresponding power storage member in a state where the plurality of disconnection circuits associated with each of the power storage members is disposed, the current storage unit is configured to prevent current from flowing through the power storage member. Detach the parts,
The control circuit included in the power supply device controls whether to continue the charge / discharge operation of the power storage circuit based on the connection position of the failed power storage member among the plurality of power storage members.
Power control method.

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