JP2020025404A - Charge/discharge device and power storage system - Google Patents

Abstract

To solve the problem that occurrence of deterioration could not be prevented when changing a charging method or a voltage value after acquiring a measurement indicating the occurrence of deterioration in a secondary battery.SOLUTION: A charge/discharge device for a secondary battery using an electrolyte comprises: a charge control section which performs intermittent charge control for alternately repeating high-voltage charge for applying a pulse-like high voltage to the secondary battery and low-voltage charge for applying a low voltage which is equal to or higher than an electromotive force in the case of complete discharge of the secondary battery and lower than the high voltage, to the secondary battery; and a parameter acquisition section for acquiring values of at least two parameters among an operation parameter corresponding to the amount of operation including charge/discharge of the secondary voltage, a charge parameter corresponding to the amount of charging to the secondary battery, and a deterioration parameter corresponding to deterioration of the secondary battery. The charge control section controls at least one of a charging voltage and a charging current in the intermittent charge control on the basis of a relationship between the values of the at least two parameters acquired by the parameter acquisition section.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a charge / discharge device and a power storage system.

By performing constant current charging on the secondary battery, determining that decomposition and reduction of the electrolytic solution and corrosion of the electrode grid have occurred by detecting an increase in the polarization voltage, and terminating the charging, 2. Description of the Related Art There is known a technique that enables rapid charging while suppressing deterioration of a secondary battery (for example, see Patent Document 1). Further, trickle charging is performed on the secondary battery to prevent crystallized lead sulfate, that is, sulfation, from being generated on the negative electrode, and the charge amount of the secondary battery becomes equal to or more than the first SOC (States of Charge) upper limit value. Is detected, the charging is switched to pulse charging in which high-voltage charging with a pulsed high voltage and low-voltage charging with a relatively low voltage are alternately repeated, and the SOC becomes higher than or equal to the SOC protection threshold higher than the first SOC upper limit. A technique is known in which pulse charging is stopped when this is detected (for example, see Patent Document 2). Also, there is a technique of performing the above-described pulse charging on a secondary battery and adjusting the voltage value and charging time of high-voltage charging or low-voltage charging based on the electromotive force, internal resistance, or usage time of the secondary battery. It is known (see, for example, Patent Document 3).
[Prior art documents]
[Patent Document]
[Patent Document 1] JP-A-2015-104139 [Patent Document 2] International Publication WO2016 / 002135 [Patent Document 3] JP-A-2017-103909

  In any of the above techniques, the charging method, the voltage value, and the like are changed after a measurement value indicating that the secondary battery has been deteriorated is obtained. The charge control could not be performed flexibly.

  The secondary battery charge / discharge device using the electrolyte may include a charge control unit and a parameter acquisition unit. The charging control unit applies high-voltage charging to apply a pulsed high voltage to the secondary battery and applies a low voltage that is equal to or higher than the electromotive force at the time of complete discharge of the secondary battery and lower than the high voltage to the secondary battery. Intermittent charging control that alternately repeats low-voltage charging may be performed. The parameter acquisition unit includes an operation parameter corresponding to an operation amount including charge / discharge of the secondary battery, a charge parameter corresponding to a charge amount of the secondary battery, and a deterioration parameter corresponding to deterioration of the secondary battery. May be obtained. The charging control unit may change at least one of a charging voltage and a charging current in the intermittent charging control based on a relationship between values of at least two parameters acquired by the parameter acquiring unit.

  The charging control unit may change at least one of the charging voltage and the charging current in the intermittent charging control depending on whether at least two parameter values satisfy a target relationship.

  The target relationship is related to deterioration due to overcharge of the secondary battery, and the charge control unit operates the operation parameter and any one of the values of the maintenance rate of the battery capacity of the secondary battery included in the deterioration parameter. It may be determined whether or not the value of the charging parameter satisfies the target relationship.

  The target relationship relates to deterioration due to overcharging of the secondary battery, and the charge control unit determines whether any one of the operation parameter and the charging parameter is equal to the chemical value on the positive electrode side of the secondary battery included in the deterioration parameter. It may be determined whether or not the value of the increase amount of the internal impedance on the positive electrode side according to the reaction satisfies the target relationship.

  The target relationship is related to deterioration due to insufficient charging of the secondary battery, and the charge control unit determines the amount of increase in the negative-side internal impedance corresponding to the chemical reaction on the negative-side of the secondary battery, which is included in the deterioration parameter. Even if it is determined whether or not any value of the battery capacity maintenance rate of the secondary battery and the amount of decrease in the electromotive force of the secondary battery and the value of the operation parameter satisfy the target relationship. Good.

  The target relationship includes a first target relationship related to deterioration due to overcharge of the secondary battery and a second target relationship related to deterioration due to insufficient charge of the secondary battery. When the charge control unit determines that the values of at least two parameters do not satisfy the first target relationship, the charge control unit reduces at least one of the charging voltage and the charging current and does not satisfy the second target relationship. If it is determined that at least one of the charging voltage and the charging current may be increased.

  When determining that the values of the at least two parameters do not satisfy the first target relationship, the charging control unit sets at least one of the charging voltage and the charging current of either the high-voltage charging or the low-voltage charging to zero. By doing so, the secondary battery may be in a no-load state.

  The parameter acquisition unit may start acquiring values of at least two parameters with the start of operation including charging and discharging of the secondary battery.

  The parameter acquisition unit may acquire the values of the operation parameters, and start acquiring the values of at least two parameters on condition that the value of the operation parameters is equal to or greater than a predetermined threshold.

  A power storage system may include the above-described charge / discharge device, a converter unit, and an inverter unit. The converter unit may convert AC power supplied from a power supply into DC power. The inverter unit may convert DC power into AC power and supply the AC power to a load.

  The above summary of the present invention does not list all of the necessary features of the present invention. Further, a sub-combination of these feature groups can also be an invention.

FIG. 2 is a block diagram of a power supply system 200. It is a flowchart of the charging method of the lead storage battery 40. 4 is a timing chart of a charging voltage in constant voltage charging control. FIG. 7 is a diagram illustrating charging control for reducing a charging voltage when the value of a charging parameter and the value of a deterioration parameter do not satisfy a first target relationship. FIG. 9 is a diagram illustrating charging control for reducing a charging voltage when the value of an operation parameter and the value of a charging parameter do not satisfy a first target relationship. FIG. 9 is a diagram illustrating charge control for increasing a charge voltage when the value of an operation parameter and the value of a deterioration parameter do not satisfy a second target relationship.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all combinations of the features described in the embodiments are necessarily essential to the solution of the invention. In the drawings, the same or similar portions are denoted by the same reference numerals, and duplicate description may be omitted.

  FIG. 1 is a block diagram of the power supply system 200. In the drawing, a black arrow indicates the input / output direction of the control signal, and a white arrow indicates the power flow direction. The same applies to the following drawings.

  Power supply system 200 includes power supply device 10 and power storage system 20. The power supply system 200 supplies power to the external load 50. In the present embodiment, as an example, the power supply device 10 is an AC power supply, and the load 50 is a load driven by AC.

  The power storage system 20 according to the present embodiment supplies the stored power to the load 50 instead of the power supply device 10 when the power supply from the power supply device 10 to the load 50 is interrupted due to an abnormal situation such as a power failure. Function as a power supply device (UPS (Uninterruptable Power Supply)). More specifically, the power storage system 20 supplies power from the power supply device 10 to the load 50 during normal operation in which power is stably supplied from the power supply device 10, and further supplies power from the power supply device 10. Store power. Power storage system 20 supplies the stored power to load 50 during an emergency operation when power supply from power supply device 10 is cut off.

  The power storage system 20 includes an input unit 12, an output unit 14, an AC / DC converter 22, a DC / AC inverter 24, a lead storage battery 40, and a charge / discharge device 100. The input unit 12 is electrically connected to the power supply device 10. The output unit 14 is electrically connected to the load 50.

  The AC / DC converter 22 is electrically connected to the input unit 12. The AC / DC converter 22 converts an AC current input from the power supply device 10 via the input unit 12 into a DC current and outputs the DC current.

  The DC / AC inverter 24 is electrically connected to the output unit 14. The DC / AC inverter 24 converts a DC current input from the AC / DC converter 22 or the charging / discharging device 100 into an AC current, and outputs the AC current to the load 50 via the output unit 14.

  The lead storage battery 40 is an example of a secondary battery using an electrolytic solution. Lead storage battery 40 is electrically connected to charge / discharge device 100. Lead storage battery 40 includes, for example, six cells connected in series to each other. The lead storage battery 40 may include an arbitrary number of cells connected in series, and an arbitrary number of cells may be further connected in parallel. The power storage system 20 may have another secondary battery such as a nickel cadmium battery or a nickel hydride battery instead of the lead storage battery 40 as the secondary battery using the electrolytic solution.

  The charge / discharge device 100 is electrically connected to a node 32 between the AC / DC converter 22 and the DC / AC inverter 24. The charge / discharge device 100 supplies the electric power from the power supply device 10 to the load 50 via the DC / AC inverter 24 and charges the lead storage battery 40 via the AC / DC converter 22 during the normal operation. I do. The charge / discharge device 100 supplies the electric power stored in the lead storage battery 40 to the load 50 via the DC / AC inverter 24 during the emergency operation. The charge / discharge device 100 may include a power conversion circuit unit (not shown) including a semiconductor switch element, and may increase or decrease the DC voltage of the node 32 and supply the DC voltage to the lead storage battery 40. The power conversion circuit is specifically a DC / DC conversion circuit, and may be a two-level chopper circuit or a three-level chopper circuit including a semiconductor switch element.

  The charging / discharging device 100 according to the present embodiment includes a high-voltage charging in which a pulsed high voltage is applied to the lead storage battery 40 and a low voltage that is equal to or higher than the electromotive force at the time of complete discharge of the lead storage battery 40 and lower than the high voltage. And intermittent charge control in which low voltage charging applied to the secondary battery is alternately repeated. Thereby, the charge / discharge device 100 suppresses electrolysis of water on the positive electrode side due to overcharging while preventing the generation of crystallized lead sulfate, that is, sulfation, on the negative electrode of the lead storage battery 40. In addition, the charge / discharge device 100 acquires the values of at least two types of parameters from the lead storage battery 40, and based on the relationship between the values of the at least two types of parameters, the lead storage battery 40 enters a charging state that will cause deterioration in the future. Is detected, the charging voltage is changed, and the trajectory is corrected. The charging / discharging device 100 thereby prevents each of the deterioration caused by overcharging of the lead storage battery 40 and the deterioration caused by insufficient charging.

  The charge / discharge device 100 includes a parameter acquisition unit 110, a charge / discharge control unit 101, and a storage unit 103.

  The parameter acquisition unit 110 acquires values of at least two types of parameters from the lead storage battery 40 and outputs the values to the charge / discharge control unit 101. The parameter acquisition unit 110 starts acquiring values of these at least two types of parameters with the start of operation including charging and discharging of the lead storage battery 40. As an example, the parameter obtaining unit 110 obtains the values of these at least two types of parameters at predetermined time intervals and outputs the values to the charge / discharge control unit 101. The parameter obtaining unit 110 includes an operation parameter obtaining unit 111, a charging parameter obtaining unit 113, and a deterioration parameter obtaining unit 115. Note that the charge / discharge control unit 101 may include the above-described power conversion circuit unit and a gate drive circuit unit for controlling on / off of a semiconductor switch element included in the power conversion circuit unit. The storage unit 103 may be included in the gate drive circuit unit, or may be included in a control circuit unit (not shown) provided separately from the gate drive circuit unit.

  Note that the parameter acquisition unit 110 may acquire the values of at least two types of parameters repeatedly at an arbitrary timing. The parameter acquisition unit 110 also measures, for example, a timer for measuring time, an ammeter for measuring a current value flowing into and out of the lead storage battery 40, a voltmeter for measuring the voltage of the lead storage battery 40, and measuring the internal impedance of the lead storage battery 40. It may include an impedance measuring device or the like. Further, the parameter acquisition unit 110 refers to the reference for performing a specific operation and the initial value of each parameter of the lead storage battery 40 stored in the storage unit 103 to obtain the value of the parameter obtained from the lead storage battery 40. May be converted and output to the charge / discharge control unit 101.

  The operation parameter acquisition unit 111 acquires an operation parameter value according to the amount of operation including charging and discharging of the lead storage battery 40. The operation parameter is a parameter that can directly or indirectly indicate the amount of operation of the lead-acid battery 40, and as an example, the total time since the start of operation of the lead-acid battery 40, the operation of the lead-acid battery 40 The total time after a predetermined time has elapsed from the start, the total time since the start of the intermittent charge control for the lead storage battery 40, and the amount of discharge from the lead storage battery 40 and the amount of charge to the lead storage battery 40 At least one of the total charge / discharge amount and the like.

  The charging parameter acquisition unit 113 acquires a value of a charging parameter according to the amount of charge to the lead storage battery 40. The charging parameter is a parameter that can directly or indirectly indicate the amount of charge to the lead-acid battery 40, and as an example, the total amount of charge to the lead-acid battery 40 from the start of operation of the lead-acid battery 40 or The average charge amount, the total charge amount or the average charge amount to the lead storage battery 40 after a predetermined time has elapsed since the operation of the lead storage battery 40 has started, and the intermittent charge control for the lead storage battery 40 has been started. At least one of the total charge amount or the average charge amount of the lead storage battery 40 from the battery.

  The deterioration parameter obtaining unit 115 obtains a value of the deterioration parameter according to the deterioration of the lead storage battery 40. The deterioration parameter is a parameter that can directly or indirectly indicate the deterioration of the lead storage battery 40, and includes a characteristic that changes according to the deterioration of the lead storage battery 40. As an example, the deterioration parameter decreases the electromotive force of the lead storage battery 40. It includes at least one of the quantity and the maintenance rate of the battery capacity of the lead storage battery 40. The electromotive force is a voltage output from the lead storage battery 40 in a no-load state. The amount of decrease in the electromotive force is a value obtained by subtracting the current electromotive force from the electromotive force at the time when the operation of the lead storage battery 40 is started. If the amount of charge to the lead storage battery 40 is insufficient, sulfation occurs at the negative electrode of the lead storage battery 40 and the potential of the negative electrode increases, so that the electromotive force of the lead storage battery 40 decreases. Therefore, it is possible to indirectly determine the deterioration caused by insufficient charging of the lead storage battery 40 based on the value of the amount of decrease in the electromotive force of the lead storage battery 40.

  When the lead storage battery 40 is charged by the alternating current, the deterioration parameter value is determined by the amount of increase in the internal impedance of the lead storage battery 40 on the positive electrode side, that is, the positive electrode side according to the chemical reaction on the high frequency side, and the negative electrode of the lead storage battery 40. Or at least one of an increase amount of the internal impedance on the negative electrode side according to the chemical reaction on the low frequency side. The chemical reaction at each electrode of the lead storage battery 40 has frequency dependency, and the chemical reaction on the positive electrode side is on the high frequency side of the internal impedance, for example, 0.1 Hz to 300 kHz, more preferably 0.5 Hz to 50 Hz. The chemical reaction on the negative electrode side depends on the low frequency side of the internal impedance, for example, in the range of 0.1 Hz to 0.01 Hz.

  The charge / discharge control unit 101 is electrically connected to each of the node 32 and the lead storage battery 40, and controls charging and discharging of the lead storage battery 40. The charge / discharge control unit 101 performs the above-described intermittent charge control on the lead storage battery 40, and the relationship between the values of at least two of the operation parameter, the charge parameter, and the deterioration parameter input from the parameter acquisition unit 110 , The charge voltage in the intermittent charge control is changed, and the lead storage battery 40 is charged and discharged. As an example, the charge / discharge control unit 101 changes the charge voltage in the intermittent charge control depending on whether the values of these at least two types of parameters satisfy a target relationship, and charges / discharges the lead storage battery 40. The target relationship is, for example, a first target relationship related to deterioration due to overcharge of the secondary battery and a second target related to deterioration due to insufficient charge of the secondary battery. Including relationships.

  As an example, when determining that the values of at least two types of parameters acquired by the parameter acquisition unit 110 do not satisfy the first target relationship, the charge / discharge control unit 101 reduces the charging voltage. For example, when the charge / discharge control unit 101 determines that the values of the at least two types of parameters do not satisfy the second target relationship, the charge / discharge control unit 101 increases the charge voltage.

  Note that the target relationship includes only one of the first target relationship and the second target relationship, and the charge / discharge control unit 101 determines whether the at least two types of parameters are the same. It may be determined whether or not the value satisfies one of the target relationships, and the charging voltage may be changed. Further, the charge / discharge control unit 101 may change the charge current in the intermittent charge control based on the relationship between the values of at least two types of parameters acquired by the parameter acquisition unit 110, and charge / discharge the lead storage battery 40. . When the charge / discharge control unit 101 determines that the values of the at least two types of parameters do not satisfy the first target relationship, the charge voltage of one of the high-voltage charge and the low-voltage charge in the intermittent charge control is determined. By setting at least one of the charging current and the charging current to zero, the lead storage battery 40 may be set in the no-load state.

  When the charge amount of the lead-acid battery 40 is equal to or less than a predetermined charge rate, the charge / discharge control unit 101 performs constant-current charging on the lead-acid battery 40 instead of intermittent charging. May be quickly charged. Further, the charge / discharge control unit 101 stores a predetermined threshold or a predetermined threshold value for the relationship between the values of at least two types of parameters stored in the storage unit 103 and the relationship between the values of the at least two types of parameters. The charge and discharge of the lead storage battery 40 may be controlled with reference to conditions for executing a specific charge and discharge control, a predetermined charge and discharge pattern, and the like. Note that the charge / discharge control unit 101 is an example of a charge control unit.

  FIG. 2 is a flowchart of a method for charging the lead storage battery 40. The flow is started, for example, by the charge / discharge control unit 101 starting the intermittent charge control after charging the lead storage battery 40 with a constant current until the charging rate reaches a predetermined charging rate. The charge / discharge control unit 101 performs constant current / constant voltage charging (CCCV charging) during a period from a constant current charging stage to a transition to an intermittent charging stage. The current value in CCCV charging is set to a predetermined magnitude, for example, 0.25C. However, when the process proceeds to the intermittent charging stage, the current value fluctuates so that the voltage value becomes a predetermined value. For example, the current value during the low-voltage charging period in the intermittent charging stage alternates between values close to 0C. 1C means a current value at which the full charge capacity of the lead storage battery 40 is discharged in one hour.

  The parameter acquisition unit 110 waits until a predetermined time elapses (step S101: NO), and when the time elapses (step S101: YES), three types of parameter values, that is, operation parameters, The respective values of the charging parameter and the deterioration parameter are obtained and output to the charge / discharge control unit 101 (step S103).

  The charge / discharge control unit 101 determines that, among the three types of parameter values acquired by the parameter acquisition unit 110, the value of the charging parameter and the value of the deterioration parameter are the first values related to the deterioration caused by overcharging of the lead storage battery 40. It is determined whether or not the target relationship is satisfied (step S105). If the target relationship is satisfied (step S105: YES), the charging voltage to the lead storage battery 40 is reduced (step S107). : NO), and the charging voltage to the lead storage battery 40 is not reduced.

  The charge / discharge control unit 101 determines that the value of the operation parameter and the value of the deterioration parameter among the three types of parameter values acquired by the parameter acquisition unit 110 are the second values related to the deterioration caused by insufficient charging of the lead storage battery 40. Is determined (step S109), if it is satisfied (step S109: YES), the charging voltage to the lead storage battery 40 is increased (step S111), and if it is not satisfied (step S109). : NO), the charging voltage to the lead storage battery 40 is not increased. Thus, the flow ends. This flow is repeated as long as power is continuously supplied from power supply device 10 to power storage system 20.

  FIG. 3 is a timing chart of the charging voltage in the intermittent charging control. The horizontal axis indicates time [sec], and the vertical axis indicates voltage [V].

T _H shown in FIG. 3 is a high voltage charge period for applying a high voltage to the lead-acid battery 40, T _L is a low-voltage charging period for applying a low voltage to the lead-acid battery 40. Discharge control unit 101, as shown in FIG. 3, by the intermittent charge control is repeated several times one cycle consisting of T _L for applying the T _H and a low voltage to a high voltage is applied to the lead-acid battery 40. T _L is longer than _{T H,} may be 240 seconds to 5 hours as an example of the _{T L,} may be a 60 seconds to 5 hours as an example of a _{T H.} The ratio is preferably one sixty between _{T H} and _{T L} in one cycle, for example, 3,600 [sec] of the _{T L} a _{T H} as 60 [sec].

  The charge / discharge control unit 101 applies a pulsed high voltage to the lead storage battery 40 during the high voltage charging period. The pulse-like high voltage means a voltage waveform in which the voltage value rises sharply in a short time. The pulsed high voltage may be 2.00 to 3.00 V per cell of the lead-acid battery 40, and is set to 2.23V in this embodiment, which is 13.38 V peak for the whole series cell of the lead-acid battery 40. It has a rectangular wave shape to which a voltage is applied. Note that the pulsed high voltage may have a half-cycle waveform shape including a peak in a sine wave, a triangular wave, or a sawtooth wave, instead of the rectangular wave shape. Note that the pulsed high voltage may be equal to or less than the rated charging voltage of the specification value specified by the battery manufacturer.

  The charge / discharge control unit 101 applies a low voltage to the lead storage battery 40 to suppress the deterioration of the negative electrode of the lead storage battery 40 during the low voltage charging period. The low voltage is higher than 0 [V] and equal to or lower than the high voltage, and may be 1.50 to 3.00 V per cell of the lead storage battery 40. The low voltage is preferably equal to or higher than the electromotive force of the lead storage battery 40 at the time of complete discharge. For example, when the electromotive force at the time of complete discharge of one cell is 1.95 [V], the low voltage is set to 11.7 [V] or more.

  Further, the low voltage is preferably 93% or more of the theoretical electromotive force in the lead storage battery 40. When the theoretical electromotive force of one cell is 2.04 [V], the low voltage is set to about 11.4 [V] or more. The case where the low voltage is 93% or more of the theoretical electromotive force may mean that the instantaneous minimum value of the low voltage is 90% or more of the theoretical electromotive force.

  Further, it is preferable that the low voltage is equal to or lower than the electromotive force when the lead storage battery 40 is fully charged. When the electromotive force at the time of complete charging of one cell is 2.1 [V], the low voltage is set to 12.6 [V] or less. Further, the low voltage is preferably 121% or less of the voltage value of the theoretical electromotive force in the lead storage battery 40. When the theoretical electromotive force of one cell is 2.04 [V], the low voltage is set to about 14.8 [V]. Based on the above points, in the present embodiment, the low voltage is set to 2.10 V per cell of the lead storage battery 40, and a voltage of 12.60 V is applied to the entire series cells of the lead storage battery 40.

  The charge / discharge control unit 101 can shorten the period of the high-voltage charge by applying a high voltage to the lead-acid battery 40 in a pulse shape in the intermittent charge control, as compared with the trickle charge that always performs the high-voltage charge. In addition, it is possible to prevent water, which is a solvent of the electrolytic solution in the lead storage battery 40, from being electrolyzed and releasing hydrogen gas and oxygen gas to the outside. In addition, the charge / discharge control unit 101 applies a high voltage in a pulsed manner to the lead storage battery 40 in the intermittent charging control, thereby suppressing the formation of lead oxide on the positive electrode of the lead storage battery 40 and the occurrence of volume expansion. It is also possible to periodically decompose the sulfation generated on the negative electrode.

  The charge / discharge control unit 101 applies self-discharge to the lead-acid battery 40 in the intermittent charge control by applying a voltage higher than 0 [V] or a low voltage equal to or higher than the electromotive force at the time of complete discharge. Can be suppressed.

  FIG. 4 is a diagram illustrating charging control for reducing the charging voltage when the value of the charging parameter and the value of the deterioration parameter do not satisfy the first target relationship. The horizontal axis in FIG. 4 shows the total charge amount [Ah] to the lead storage battery 40 as an example of the charge parameter. Since the total amount of charge to the lead-acid battery 40 is substantially proportional to the operation time, which is the total time since the start of operation of the lead-acid battery 40, the temporal change of each parameter is shown in the positive direction of the horizontal axis in FIG. Occurs. The vertical axis of FIG. 4 indicates, in order from the top, the battery capacity retention rate of the lead storage battery 40 as an example of the deterioration parameter and the charging voltage [V] during the high-voltage charging period in the intermittent charging control.

  FIG. 4 shows a target line defining a first target relationship. The target line is based on, for example, a specification value specified by the battery maker. Here, if the total charge amount is defined as a function X, the battery capacity maintenance rate is defined as a function Y, the slope of the target line is defined as a constant A, and the intercept on the vertical axis of the target line is defined as a hatched line in FIG. The range of the first target relationship is represented by Y ≧ AX + B.

  FIG. 4 also shows six plotted acquisition parameters as a relationship between the value of the total charge amount and the value of the battery capacity retention rate acquired from the lead storage battery 40 at predetermined time intervals by the parameter acquisition unit 110. Values are shown. Of the six acquired parameter values, only the central two acquired parameter values are not included in the range of the first target relationship.

  The charge / discharge control unit 101 determines that the value of the maintenance rate of the battery capacity of the lead storage battery 40 included in the deterioration parameter and the value of the charging parameter acquired by the parameter acquiring unit 110 satisfy the first target relationship. It is determined whether or not. More specifically, the charge / discharge control unit 101 determines whether or not each of the six acquisition parameter values shown in FIG. 4 is included in the range of the first target relationship in a time-series manner. That is, the determination is made sequentially along the positive direction of the horizontal axis.

  The charge / discharge control unit 101 determines that the first and second acquired parameter values in the positive direction of the horizontal axis in FIG. 4 are included in the range of the first target relationship, and determines that the intermittent charge control has been set. The intermittent charge of the lead storage battery 40 is maintained without changing the value.

  The charge / discharge control unit 101 determines that the third acquired parameter value in the positive direction of the horizontal axis in FIG. 4 is not included in the range of the first target relationship, and determines the charging voltage during the high-voltage charging period as: As an example, the voltage value is lowered by 2% from the voltage value at the time when the obtained parameter value is obtained.

  Further, the charge / discharge control unit 101 determines that the fourth acquisition parameter value in the positive direction of the horizontal axis in FIG. 4 is not yet included in the range of the first target relationship, and performs the charging during the high-voltage charging period. The voltage is reduced by 2% from the voltage value at the time when the obtained parameter value is obtained. As a result, the fifth and subsequent acquired parameter values in the positive direction of the horizontal axis in FIG. 4 are included in the range of the first target relationship, in other words, the battery capacity maintenance ratio of the lead storage battery 40. The rate of decrease over time is small.

  By controlling the charging of the lead storage battery 40 in this way, the charging / discharging control unit 101 detects that the lead storage battery 40 is in an overcharged state that will cause deterioration in the future, and changes the charging voltage to quickly Orbit correction. Thereby, the charge / discharge device 100 can prevent the occurrence of deterioration due to overcharging of the lead storage battery 40. Note that, instead of or in addition to reducing the charging voltage during the high-voltage charging period, the charging / discharging control unit 101 may similarly decrease the charging voltage during the low-voltage charging period. Further, instead of lowering the charging voltage by 2% of the preset value, the charge / discharge controller 101 may lower the charging voltage by, for example, 20 mV per cell. In these cases, the same effects as above can be obtained.

  FIG. 5 is a diagram illustrating charging control for reducing the charging voltage when the value of the operation parameter and the value of the charging parameter do not satisfy the first target relationship. The charge / discharge control unit 101 may perform the charge control described in FIG. 5 instead of the charge control described in FIG.

  The horizontal axis in FIG. 5 shows the operation time [day] which is the total time from the start of operation of the lead storage battery 40 as an example of the operation parameter, and the vertical axis in FIG. A total charge amount [Ah] to the lead storage battery 40 as an example and a charge voltage [V] during a high voltage charge period in intermittent charge control are shown.

  FIG. 5 shows a target line defining a first target relationship. The target line is, for example, data obtained when intermittent charging is performed on another standard lead storage battery under the same conditions as the intermittent charging control performed on the lead storage battery 40 by the charge / discharge control unit 101. And may be theoretical data obtained by simulation or measurement data obtained by experiment. Here, if the operation time is defined as a function X, the total charge amount is defined as a function Y, the slope of the target line is defined as a constant A, and the intercept on the vertical axis of the target line is defined as B, a hatched line in FIG. The range of the target relationship of 1 is represented by Y ≦ AX + B.

  FIG. 5 shows six plotted acquisition parameter values as a relationship between the operation time value and the total charge amount acquired from the lead storage battery 40 at each predetermined time interval by the parameter acquisition unit 110. It is shown. Of the six acquired parameter values, only the central two acquired parameter values are not included in the range of the first target relationship.

  The charge / discharge control unit 101 determines whether the value of the operation parameter and the value of the charge parameter acquired by the parameter acquisition unit 110 satisfy a first target relationship. More specifically, the charge / discharge control unit 101 determines whether or not each of the six acquisition parameter values illustrated in FIG. 5 is included in the range of the first target relationship in a time-series manner. That is, the determination is made sequentially along the positive direction of the horizontal axis.

  The charge / discharge control unit 101 determines that the first and second acquired parameter values in the positive direction of the horizontal axis in FIG. 5 are included in the range of the first target relationship, and determines that the intermittent charge control has been set. The intermittent charge of the lead storage battery 40 is maintained without changing the value.

  The charge / discharge control unit 101 determines that the third acquired parameter value in the positive direction of the horizontal axis in FIG. 5 is not included in the range of the first target relationship, and determines the charging voltage during the high-voltage charging period, As an example, the voltage value is lowered by 2% from the voltage value at the time when the obtained parameter value is obtained.

  Further, the charge / discharge control unit 101 determines that the fourth acquired parameter value in the positive direction of the horizontal axis in FIG. 5 is not yet included in the range of the first target relationship, and performs charging during the high-voltage charging period. The voltage is reduced by 2% from the voltage value at the time when the obtained parameter value is obtained. As a result, the fifth and subsequent acquisition parameter values in the positive direction of the horizontal axis in FIG. 5 are included in the range of the first target relationship, in other words, the total charge amount of the lead storage battery 40. The rate of increase over time is small. The charge / discharge control unit 101 also has the same effect as the charge control in FIG. 4 when performing the charge control described in FIG. 5 instead of the charge control described in FIG.

  FIG. 6 is a diagram illustrating charging control for increasing the charging voltage when the value of the operation parameter and the value of the deterioration parameter do not satisfy the second target relationship. The charge / discharge control unit 101 may perform the charge control described in FIG. 6 in addition to the charge control described in FIG. 4 or the charge control described in FIG.

  The horizontal axis in FIG. 6 shows the operation time [day] which is the total time from the start of operation of the lead storage battery 40 as an example of the operation parameter, and the vertical axis in FIG. An example of the electromotive force drop amount [V] of the lead storage battery 40 and a charging voltage [V] during a high voltage charging period in intermittent charging control are shown.

  FIG. 6 shows a target line that defines a second target relationship. The target line is based on, for example, a specification value specified by the battery maker. Here, if the operation time is defined as a function X, the amount of decrease in electromotive force is defined as a function Y, the slope of the target line is defined as a constant A, and the intercept on the vertical axis of the target line is defined as B, the hatched lines in FIG. The range of the second target relationship is represented by Y ≦ AX + B.

  FIG. 6 shows six plotted acquisition parameter values as a relationship between the operation time value and the electromotive force decrease value acquired from the lead storage battery 40 at each predetermined time interval by the parameter acquisition unit 110. It is shown. Of the six acquired parameter values, only the central two acquired parameter values are not included in the range of the second target relationship.

  The charge / discharge control unit 101 determines whether or not the value of the amount of decrease in the electromotive force of the lead storage battery 40 included in the deterioration parameter acquired by the parameter acquisition unit 110 and the value of the operation parameter satisfy the target relationship. judge. More specifically, the charge / discharge control unit 101 determines whether or not each of the six acquisition parameter values shown in FIG. 6 is included in the range of the second target relationship in a time-series manner. That is, the determination is made sequentially along the positive direction of the horizontal axis.

  The charge / discharge control unit 101 determines that the first and second acquired parameter values in the positive direction of the horizontal axis in FIG. 6 are included in the range of the second target relationship, and determines that the intermittent charge control has been set. The intermittent charge of the lead storage battery 40 is maintained without changing the value.

  The charge / discharge control unit 101 determines that the third acquired parameter value in the positive direction of the horizontal axis in FIG. 6 is not included in the range of the second target relationship, and determines the charge voltage during the high-voltage charge period. As an example, the voltage is increased by 2% from the voltage value at the time when the obtained parameter value is obtained.

  Further, the charge / discharge control unit 101 determines that the fourth acquired parameter value in the positive direction of the horizontal axis in FIG. 6 is not yet included in the range of the second target relationship, and performs charging during the high-voltage charging period. The voltage is increased by 2% from the voltage value at the time when the obtained parameter value was obtained. As a result, the fifth and subsequent acquired parameter values in the positive direction of the horizontal axis in FIG. 6 are included in the range of the second target relationship, in other words, the amount of decrease in the electromotive force of the lead storage battery 40. The rate of increase over time is small.

  By controlling the charging of the lead storage battery 40 in this way, the charging / discharging control unit 101 detects that the lead storage battery 40 is in an insufficiently charged state that causes deterioration in the future, changes the charging voltage, and Orbit correction. Thereby, the charge / discharge device 100 can prevent the occurrence of deterioration due to insufficient charging of the lead storage battery 40. Note that, instead of or in addition to increasing the charging voltage during the high voltage charging period, the charge / discharge control unit 101 may similarly increase the charging voltage during the low voltage charging period. Further, instead of increasing the charge voltage by 2% of the preset value, the charge / discharge control unit 101 may increase the charge voltage by, for example, 20 mV per cell. In these cases, the same effects as above can be obtained.

  According to the charge / discharge device 100 in the above embodiment, by performing intermittent charge control on the lead storage battery 40, it is possible to prevent the occurrence of sulfation at the negative electrode of the lead storage battery 40, and to prevent the generation of water on the positive electrode side. Not only can decomposition be suppressed, but also by acquiring the values of at least two types of parameters from the lead storage battery 40 and changing the charging voltage or charging current based on the relationship between the values of the at least two types of parameters, It is possible to prevent the deterioration caused by overcharging and the deterioration caused by insufficient charging, respectively.

  In the above embodiment, the parameter acquisition unit 110 has been described as starting to acquire the values of these at least two types of parameters when the operation including the charging and discharging of the lead storage battery 40 is started. Instead, the parameter acquisition unit 110 acquires the value of the operation parameter, and sets the value of the operation parameter, for example, the operation time from the start of the operation including charging and discharging of the lead storage battery 40 to the predetermined threshold or more. It may start to acquire the values of at least two types of parameters on condition that it has become.

  In the above embodiment, in order to prevent the occurrence of deterioration due to overcharging of the lead storage battery 40, the charge / discharge control unit 101 uses the charge control described with reference to FIG. 3 and FIG. It has been described that the charge control described above is performed. Instead of this, the charge / discharge control unit 101 calculates the value of any one of the operation parameter and the charge parameter and the value of the increase amount of the positive-side internal impedance corresponding to the chemical reaction on the positive electrode side of the lead-acid battery 40 included in the deterioration parameter. It may be determined whether or not satisfies the first target relationship, and if the first target relationship is not satisfied, the charging voltage may be reduced.

  In the above embodiment, the charge / discharge control unit 101 has been described as performing the charge control described with reference to FIGS. 3 and 6 in order to prevent occurrence of deterioration due to insufficient charging of the lead storage battery 40. Instead, the charge / discharge control unit 101 determines the value of the amount of increase in the internal impedance on the negative electrode side according to the chemical reaction on the negative electrode side of the lead storage battery 40 or the value of the maintenance rate of the battery capacity of the lead storage battery 40 included in the deterioration parameter. And whether the value of the operation parameter satisfies the second target relationship may be determined. If the second target relationship is not satisfied, the charging voltage may be increased.

  In the above embodiment, the range of the first target relationship to be satisfied by the value of the charging parameter and the value of the deterioration parameter illustrated by using FIG. 4 and the operation parameter illustrated by using FIG. , And the range of the first target relationship to be satisfied by the value of the charging parameter, and the second target to be satisfied by the value of the operation parameter and the value of the deterioration parameter exemplarily described with reference to FIG. Each range of the relationship was represented by a first-order inequality of the value of each parameter. Alternatively, the target relationship between the values of any two of these three parameters may be represented by an arbitrary relational expression. For example, a function of the values of any two of the parameters is predetermined. May be represented by a relational expression indicating that the difference is equal to or greater than the threshold value.

  In the above embodiment, for example, the charge / discharge control unit 101 performs the intermittent charge control based on the relationship between the values of two parameters of the operation parameter, the charge parameter, and the deterioration parameter, that is, based on the two-dimensional relationship. In the above description, the charging voltage or the charging current is changed. Instead, the charge / discharge control unit 101 changes the charge voltage or the charge current in the intermittent charge control based on the relationship between the operation parameter, the charge parameter, and the value of the deterioration parameter, that is, based on the three-dimensional relationship. Is also good. For example, in the XYZ space, when the value of the charging parameter is taken on the X-axis, the value of the deterioration parameter is taken on the Y-axis, and the value of the operation parameter is taken on the Z-axis, an example is shown in FIG. The range of the first target relationship that the value of the charging parameter and the value of the deterioration parameter should satisfy to be described in detail is shown. In the ZY plane, as an example, the value of the operation parameter described with reference to FIG. And a range of a second target relationship to be satisfied by the value of the deterioration parameter. In this case, the charge / discharge control unit 101 sets the operation parameter, the charge parameter, and the deterioration parameter in the range included in both the first target relationship range and the second target relationship range in the XYZ space. It may be determined whether or not a value is included. Further, in this case, the charge / discharge control unit 101 determines that the values of the operation parameter, the charge parameter, and the deterioration parameter are within the range of the first target relationship and the range of the second target relationship in the XYZ space. If it is determined that both are not included, it may be determined that some abnormality has occurred in at least one of the lead storage battery 40 and the charging / discharging device 100.

  In the above-described embodiment, the charge / discharge control unit 101 acquires the total charge amount to the lead storage battery 40 and the measured value of the increase amount of the positive electrode side internal impedance for each operation time acquired by the parameter acquisition unit 110, The first target relationship stored in the data table of the storage unit 103 includes the total charge amount to the lead-acid battery 40, the increase in the positive-side internal impedance of the lead-acid battery 40, and the battery capacity maintenance of the lead-acid battery 40. When the ratio of the measured value to the target value is 1 or more using the total charge amount for each operation time and the target value of the increase amount of the internal impedance on the positive electrode side derived from the relational expression with the rate, the first target May not be satisfied. The charge / discharge control unit 101 also measures the measured values of the amount of decrease in the electromotive force of the lead storage battery 40 and the amount of increase in the negative side internal impedance of the lead storage battery 40 for each operation time acquired by the parameter acquisition unit 110, Relationship between the amount of decrease in electromotive force of lead storage battery 40, the increase in negative electrode side internal impedance of lead storage battery 40, and the battery capacity retention rate of lead storage battery 40 as a second target relationship stored in the data table When the ratio of the measured value to the target value is 1 or more using the electromotive force drop amount for each operation time and the target value of the increase amount of the negative side internal impedance derived from the equation, the relationship as the second target May not be satisfied.

  In the above embodiment, the power storage system 20 has been described as having the AC / DC converter 22 and the DC / AC inverter 24. Alternatively, when load 50 operates with direct current, power storage system 20 may not have DC / AC inverter 24. When power supply device 10 supplies a direct current to power storage system 20, power storage system 20 may not have AC / DC converter 22.

  In the above embodiment, the power storage system 20 has been described as functioning as a UPS. Instead, the power storage system 20 stores the power and supplies the load 50 to the power storage device when the power device 10 converts natural energy such as sunlight or wind power into power and outputs the power, or an electric vehicle (EV) May be used as a battery device or the like that is mounted on a vehicle and supplies electric power to the EV. In addition, the power storage system 20 is mounted on a DC / AC converter (PCS) that stores electric power as a receiver of natural energy generated excessively, and is mounted on a plug-in hybrid vehicle (PHV) and a hybrid car to supply power thereto. It may be used as a battery device or the like.

  In the embodiments described above, “the element A and the element B are electrically connected” is not limited to the case where the element A and the element B are physically connected. For example, the input and output windings of the transformer are not physically connected, but are electrically connected. Further, a member for electrically connecting the element A and the element B may be interposed between the element A and the element B. Examples of the above members include a conductor, a switch or a switch, and a transformer.

  In the above embodiments, each unit of the charging / discharging device 100 may be realized by hardware, may be realized by software, or may be realized by hardware and software. At least a part of each unit of the charge / discharge device 100 may be realized by a single server, or may be realized by a plurality of servers. At least a part of each unit of the charge / discharge device 100 may be realized on a virtual machine or a cloud system.

  At least a part of each unit of the charge / discharge device 100 may be realized by a personal computer or a mobile terminal. Examples of the mobile terminal include a mobile phone, a smartphone, a PDA, a tablet, a notebook computer or a laptop computer, and a wearable computer. Each unit of the charging / discharging device 100 may store information using a distributed ledger technology such as a block chain or a distributed network.

  When at least a part of the components configuring the charging / discharging device 100 is realized by software, the components realized by the software define operations related to the components in an information processing apparatus having a general configuration. It may be realized by starting a program that has been executed. The information processing device includes, for example, (i) a data processing device having a processor such as a CPU and a GPU, a ROM, a RAM, a communication interface, and the like, and (ii) a keyboard, a touch panel, a camera, a microphone, various sensors, and a GPS receiver. And (iii) an output device such as a display device, a speaker, and a vibration device, and (iv) a storage device (including an external storage device) such as a memory and an HDD.

  Various embodiments of the invention may be described with reference to flowcharts and block diagrams, wherein blocks are (1) steps in a process in which an operation is performed or (2) devices responsible for performing an operation. Section. Certain stages and sections are implemented by dedicated circuitry, programmable circuitry provided with computer readable instructions stored on computer readable media, and / or processors provided with computer readable instructions stored on computer readable media. May be. Dedicated circuits may include digital and / or analog hardware circuits, and may include integrated circuits (ICs) and / or discrete circuits. Programmable circuits include logical AND, logical OR, logical XOR, logical NAND, logical NOR, and other logical operations, memory elements such as flip-flops, registers, field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), etc. And the like, and may include reconfigurable hardware circuits.

  Computer readable media may include any tangible device capable of storing instructions for execution by a suitable device, such that computer readable media having instructions stored thereon is specified in a flowchart or block diagram. Product comprising instructions that can be executed to create a means for performing the operation. Examples of the computer-readable medium may include an electronic storage medium, a magnetic storage medium, an optical storage medium, an electromagnetic storage medium, a semiconductor storage medium, and the like. More specific examples of computer readable media include floppy disks, diskettes, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM or flash memory), Electrically erasable programmable read only memory (EEPROM), static random access memory (SRAM), compact disk read only memory (CD-ROM), digital versatile disk (DVD), Blu-ray (RTM) disk, memory stick, integrated A circuit card or the like may be included.

  The computer readable instructions may be assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setting data, or object oriented programming such as Smalltalk, JAVA, C ++, etc. Language, and any source or object code written in any combination of one or more programming languages, including conventional procedural programming languages such as the "C" programming language or similar programming languages. Good.

  The computer readable instructions may be provided to a processor or programmable circuit of a general purpose computer, special purpose computer, or other programmable data processing device, either locally or over a wide area network (WAN) such as a local area network (LAN), the Internet, or the like. ) May be executed to create means for performing the operations specified in the flowcharts or block diagrams. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, and the like.

  As described above, the present invention has been described using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is apparent to those skilled in the art that various changes or improvements can be made to the above embodiment. In addition, matters described in a specific embodiment can be applied to other embodiments within a technically consistent range. Also, each component may have the same features as other components having the same name and different reference numerals. It is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of processes such as operations, procedures, steps, and steps in the apparatuses, systems, programs, and methods shown in the claims, the description, and the drawings is particularly “before” or “before”. It should be noted that they can be realized in any order as long as the output of the previous process is not used in the subsequent process. Even if the operation flow in the claims, the specification, and the drawings is described using “first,” “second,” or the like for convenience, it means that it is essential to perform the operation in this order. Not something.

Reference Signs List 10 power supply device, 12 input unit, 14 output unit, 20 power storage system, 22 AC / DC converter, 24 DC / AC inverter, 32 nodes, 40 lead storage battery, 50 load, 100 charge / discharge device, 101 charge / discharge control unit, 103 Storage unit, 110 parameter acquisition unit, 111 operation parameter acquisition unit, 113 charging parameter acquisition unit, 115 deterioration parameter acquisition unit, 200 power supply system

Claims (10)

A charge and discharge device for a secondary battery using an electrolytic solution,
A high-voltage charging for applying a pulsed high voltage to the secondary battery; and a low-voltage charging for applying a low voltage that is equal to or higher than the electromotive force at the time of complete discharge of the secondary battery and lower than the high voltage to the secondary battery. A charge control unit that performs intermittent charge control that alternately repeats voltage charge and
At least one of an operation parameter corresponding to an operation amount including charge and discharge of the secondary battery, a charge parameter corresponding to a charge amount to the secondary battery, and a deterioration parameter corresponding to deterioration of the secondary battery And a parameter acquisition unit that acquires the values of the two parameters.
The charging control unit changes at least one of a charging voltage and a charging current in the intermittent charging control based on a relationship between values of the at least two parameters acquired by the parameter acquiring unit.
Charge / discharge device. The charging control unit changes at least one of a charging voltage and a charging current in the intermittent charging control depending on whether or not the values of the at least two parameters satisfy a target relationship.
The charge / discharge device according to claim 1. The target relationship is related to deterioration due to overcharge of the secondary battery,
The charge control unit may determine whether the operation parameter, and any value of the battery capacity retention rate of the secondary battery included in the deterioration parameter, and the value of the charge parameter satisfy the target relationship. Determine whether or not
The charge / discharge device according to claim 2. The target relationship is related to deterioration due to overcharge of the secondary battery,
The charging control unit may be configured to set the value of any of the operation parameter and the charging parameter, and the value of the increase amount of the internal impedance on the positive electrode side included in the deterioration parameter in accordance with the chemical reaction on the positive electrode side of the secondary battery. Determining whether the target relationship is satisfied,
The charging / discharging device according to claim 2. The target relationship is related to deterioration due to insufficient charging of the secondary battery,
The charge control unit includes, in the deterioration parameter, an increase amount of a negative electrode side internal impedance according to a chemical reaction on a negative electrode side of the secondary battery, a maintenance rate of a battery capacity of the secondary battery, and the secondary battery. It is determined whether any value of the amount of decrease in the electromotive force of the battery and the value of the operation parameter satisfy the target relationship,
The charge / discharge device according to claim 2. The target relationship is a first target related to deterioration due to overcharge of the secondary battery and a second target related to deterioration due to insufficient charge of the secondary battery. Including relationships
When the charge control unit determines that the values of the at least two parameters do not satisfy the first target relationship, the charge control unit reduces at least one of the charging voltage and the charging current to determine the second target relationship. When it is determined that does not satisfy, the charging voltage and at least one of the charging current is increased,
The charge / discharge device according to claim 2. When the charge control unit determines that the values of the at least two parameters do not satisfy the first target relationship, at least one of the charge voltage and the charge current of the high-voltage charge and the low-voltage charge The secondary battery is put in a no-load state by setting one to zero,
The charging / discharging device according to claim 6. The parameter acquisition unit starts acquiring values of the at least two parameters with the start of operation including charging and discharging of the secondary battery,
The charging / discharging device according to claim 1. The parameter acquisition unit acquires the value of the operation parameter, and starts acquiring the values of the at least two parameters on condition that the value of the operation parameter is equal to or greater than a predetermined threshold.
The charging / discharging device according to claim 1. A charge / discharge device according to any one of claims 1 to 9,
A converter for converting AC power supplied from a power supply to DC power,
An inverter unit that converts the DC power into AC power and supplies the AC power to a load;
A power storage system comprising: