JP2012182915A - Power storage apparatus, power supply unit, battery unit, and controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage apparatus capable of continuously exhibiting the performance of a power supply unit while suppressing acceleration of deterioration of a battery during charging and discharging.SOLUTION: A power storage apparatus includes: a battery section with at least one battery; a monitoring section which monitors state values as states of the battery on charging and discharging of one or more items for the battery; and a control section which controls the charging and discharging of the battery section so that any state value of the battery do not deviate from a predetermined allowance.

Description

  The present invention relates to a power storage device using a battery, a power supply device, a battery unit, and a control device.

  2. Description of the Related Art Conventionally, power supply apparatuses that store and supply power by charging and discharging a battery have been proposed. As an example of such a power supply device, Patent Document 1 discloses a device that can cope with battery abnormality.

  FIG. 12 is a configuration diagram of a power supply device (conventional example) disclosed in Patent Document 1. In FIG. As shown in the figure, the power supply device 100 includes a battery unit 105 in which battery arms A to C are connected in parallel, and a charge / discharge control device 107 that controls charge / discharge of the battery unit. Each battery arm also has a battery 101, a switch 103 connected in series with the battery, and when a battery abnormality is detected, the switch is opened to disconnect the battery arm, and a signal indicating that the switch has been opened is charged and discharged. The battery monitoring device 102 is sent to the control device 107. When receiving this signal, the charge / discharge control device 107 controls to reduce the charge / discharge current or charge / discharge power of the battery unit.

JP 2010-88202 A

  According to the above-described conventional example, it is considered that an abnormal battery arm can be separated and an increase in the burden on other battery arms can be suppressed to some extent. However, in the conventional example, since the battery arm in which the abnormality has occurred is separated from the other battery arms, it is difficult to continue normal operation and to fully exhibit the original performance.

  In addition, during the period from when one of the battery arms is disconnected until the charge / discharge current is reduced, the charge / discharge current to be borne by the disconnected battery arm is transferred to another battery arm (battery arm that is not disconnected). Will be compensated, and the current value of the other battery arm will increase. For this reason, the load on the other battery arms increases, and there is a risk that the deterioration will be accelerated.

  In view of the above-described problems, the present invention provides a power storage device that can continuously exhibit the original performance of the power supply device while suppressing the deterioration of the battery during charging and discharging, and a power supply device including the same. With the goal. It is another object of the present invention to provide a battery unit and a control device that can be components of the power storage device.

  In order to achieve the above object, a power storage device according to the present invention monitors a battery unit having at least one battery and a state value that is a state value of a battery relating to charge / discharge of one or a plurality of items for the battery. And a control unit that controls charging / discharging of the battery unit so that a state value of the battery does not deviate from a predetermined allowable value.

  According to this configuration, it is possible to continuously exhibit the original performance of the power supply device while suppressing the deterioration of the battery during charging and discharging. Note that the method for determining the deviation of the allowable value is not particularly limited, and includes, for example, a determination method based on comparison with a threshold value, a method of determining whether the allowable value is deviated based on the current value and the rate of change. May be.

  Further, in the above configuration, at least one of the state values is a current value of the battery, and the control unit performs the charging / discharging of the battery so that the current value does not deviate from the allowable value. It is good also as a structure to control. According to this configuration, it is possible to suppress deterioration promotion due to the battery current during charging and discharging.

  In the above configuration, at least one of the state values is a temperature of the battery, and the control unit controls the charge / discharge of the battery so that the temperature does not deviate from the allowable value. It is good also as a structure. According to this configuration, it is possible to suppress deterioration acceleration due to the temperature of the battery during charging and discharging.

  Further, in the above configuration, at least one of the state values is a voltage value of a battery cell included in the battery, and the control unit prevents the voltage from deviating from the upper allowable value for the battery. The charging of the battery unit may be controlled to control the discharging of the battery unit so that the voltage does not deviate from the lower allowable value. According to this configuration, it is possible to suppress deterioration promotion due to the voltage of the battery cell during charging and discharging.

  Moreover, the said structure WHEREIN: The said control part is good also as a structure which suppresses charging / discharging electric current or charging / discharging electric power, when the said state value deviates from the limit value set according to the said allowable value. In addition, as a value of charging / discharging electric power, it is possible to use the value calculated | required by multiplying the voltage value of a battery for the sum total (charging / discharging electric current) of the electric current value of each battery, for example.

  According to this configuration, for example, a value obtained by giving a certain margin to the allowable value is set as the limit value, so that the state value can be surely prevented from deviating from the allowable value.

  In the above configuration, the state value is at least a temperature of the battery or a voltage value of a battery cell included in the battery, and a deteriorated battery specifying unit that specifies a battery whose state value deviates from the limit value as a deteriorated battery. And a determination unit for determining whether or not the upper limit of the charge / discharge current or charge / discharge power allowed when the deteriorated battery is disconnected from the battery unit is higher than the current state, compared with the current state A switch unit that disconnects the deteriorated battery from the battery unit when it is determined to be high may be provided.

  According to this configuration, it is possible to disconnect a battery that is severely deteriorated according to the determination result, and to maintain the upper limit of the allowable charge / discharge current or charge / discharge power as high as possible.

  More specifically, as the above configuration, the determination unit determines whether the difference between the state value of the deteriorated battery and the state value of the other battery has deviated from a predetermined reference range. It is good also as a structure which performs the said discrimination | determination.

  The power storage device according to another aspect of the present invention controls a battery unit having at least one battery, a monitoring unit that monitors the temperature of the battery, and a charge / discharge current or charge / discharge power of the battery unit. A control unit, wherein the control unit limits an upper limit of the charge / discharge current or charge / discharge power to an upper limit value set according to a temperature of the battery. According to this configuration, the battery temperature can be prevented from becoming excessively high, and the original performance of the power supply device can be continuously exhibited while suppressing acceleration of deterioration of the battery.

  Further, a power supply device according to the present invention includes a power storage device according to any one of the above-described configurations, and a charge / discharge device that performs charge / discharge of the battery unit according to control related to charging or discharging by the control unit. It is set as the structure provided. According to this configuration, it is possible to enjoy the advantages of the power storage device according to the above configuration.

  Further, the battery unit according to the present invention monitors a state value, which is a state value of a battery relating to charging / discharging, of one or a plurality of items of the battery unit having at least one battery, and the result of the monitoring. And a monitoring unit that creates information to be used as information used to control charging / discharging of the battery unit so that the value of the state of the battery related to charging / discharging does not deviate from the allowable value. According to this configuration, it can also be used as a component of the power storage device according to the above configuration.

  Further, the control device according to the present invention is a device that controls charging / discharging of the battery, and includes information used for charging / discharging control that prevents a state value that is a state value of the battery related to charging / discharging from deviating from an allowable value. In response, the battery is charged and discharged. According to this configuration, it can also be used as a component of the power storage device according to the above configuration.

  A device for controlling charging / discharging of a battery, wherein the monitoring unit monitors a state value that is a state value of the battery relating to charging / discharging of one or a plurality of items, and the state value of the battery. In order not to deviate from the predetermined allowable value, a control monitoring device including a control unit that controls the charge / discharge can also be used as a component of the power storage device according to the above configuration.

  As described above, according to the power storage device of the present invention, the original performance of the power supply device can be continuously exhibited while suppressing the deterioration of the battery during charging and discharging. Moreover, according to the electric power apparatus which concerns on this invention, it becomes possible to enjoy the advantage of the electric power storage apparatus which concerns on this invention. The battery unit or control device according to the present invention can also be used as a component of the power storage device according to the present invention.

1 is a configuration diagram of a power supply device according to a first embodiment of the present invention. It is a flowchart about the charge / discharge control which concerns on 1st Embodiment of this invention. It is a graph regarding the state of each item at the time of suppression of charging / discharging current. It is a graph regarding the state of each item at the time of suppression of charging / discharging current. It is a graph regarding the state of each item at the time of suppression of charging / discharging current. It is a graph regarding the state of each item at the time of suppression of charging / discharging current. It is a block diagram of the power supply device which concerns on 2nd Embodiment of this invention. It is a flowchart about the charge / discharge control which concerns on 2nd Embodiment of this invention. It is a flowchart regarding the upper limit optimization operation. It is a flowchart regarding the charge / discharge control which concerns on 3rd Embodiment of this invention. It is a graph regarding the upper limit of charging / discharging current. It is a block diagram of the power supply device which concerns on a prior art example. It is a graph regarding the electric current value of each battery in a prior art example.

  Embodiments of the present invention will be described below with reference to the drawings, taking each of the first to third embodiments as an example.

1. First Embodiment [Configuration of Power Supply Device, etc.]
First, the first embodiment will be described. FIG. 1 is a configuration diagram of a power supply device according to the first embodiment. As shown in the figure, the power supply device 1 includes a plurality (three in the present embodiment) of battery units (BU1 to BU3), a control device 11, and a charge / discharge device 12. In the power supply device 1, the battery units (BU1 to BU3) and the control device 11 form a power storage device 2 having a function of storing power. Note that a plurality of battery units are not necessarily provided, and only one battery unit may be provided.

  The battery unit BU1 includes a battery Batt1 and a battery state monitoring device W1 corresponding to the battery Batt1. The battery unit BU2 includes a battery Batt2 and a battery state monitoring device W2 corresponding to the battery Batt2. The battery unit BU3 includes a battery Batt3 and a battery state monitoring device W3 corresponding to the battery Batt3.

  Each of the batteries (Batt1 to Batt3) is formed by connecting a plurality of battery cells BC (secondary batteries) that are, for example, lithium ion batteries in series. However, the battery may be formed by a single battery cell. That is, the number of battery cells provided in one battery unit may be one. Each battery (Batt1 to Batt3) has a positive electrode and a negative electrode connected to each other to form a battery block BB. That is, the battery block BB is formed such that the batteries (Batt1 to Batt3) are connected in parallel, and these batteries can be integrally charged / discharged.

  Each battery state monitoring device (W1 to W3) has a corresponding battery current value (for example, a current value flowing through the points P1 to P3 shown in FIG. 1) and a corresponding battery temperature (for example, an arbitrary battery cell). The temperature of the vicinity or the temperature of the surface of the battery cell) and the voltage value of each battery cell BC of the corresponding battery are continuously detected, and the information is sent to the control device 11.

  That is, each battery state monitoring device (W1 to W3) has a corresponding battery current detection value (current detection value Ibatt), a corresponding battery temperature detection value (temperature detection value Tbatt), and a corresponding battery. Each detection information of the voltage detection value (voltage detection value Vbatt) of each battery cell BC is sent to the control device 11. In the present embodiment, the form of the detection information is information representing a detection value for each fixed period (sampling period), but is not limited to this. For example, continuous information (analog information) It may be.

  The control device 11 performs charge / discharge control based on the detection information received from each battery state monitoring device (W1 to W3) and the external signal S received from the outside. In the present embodiment, as an example, a command value for charging / discharging current (charging current or discharging current) is sequentially determined, and information on the command value is sent to the charging / discharging device 12. The external signal S includes information on whether charging or discharging is to be performed and a control value of the charging current or discharging current, and is a signal input from the outside of the power supply device 1. For example, when the power supply device 1 is used as a power source of an electric device (for example, a personal computer), the external signal S controls a signal sent from the electric device side or the power supply device 1. This is a signal sent from a host controller (not shown).

  In addition to the form which controls the value of charging / discharging electric current as mentioned above, the form of control of charging / discharging which the control apparatus 11 performs is the voltage value of a battery to the sum total (charging / discharging electric current) of each battery, for example. It is possible to control the value of charge / discharge power obtained by multiplication.

  Charging / discharging device 12 performs charging / discharging of battery block BB in accordance with the latest command (command value) received from control device 11. That is, when the charging / discharging device 12 receives the information on the charging current command value, the charging / discharging device 12 charges the battery block BB so that the charging current becomes the command value, and when the charging / discharging device 12 receives the information on the discharging current command value, The battery block BB is discharged so that the discharge current becomes the command value.

[Battery deterioration]
Here, the deterioration of the battery will be described. When the states of the batteries (Batt1 to Batt3) are aligned, the charging / discharging current flows through each battery evenly when the battery block BB is charged / discharged.

  However, the internal resistance of the battery may increase with its use. Therefore, for each battery, it is assumed that the internal resistance is unbalanced. When such an imbalance occurs, a battery having a relatively low internal resistance is more likely to cause a current to flow than other batteries, and deterioration may be accelerated (accelerated).

  Moreover, the voltage value (cell voltage) of each battery cell which a battery has may change with use of the battery. For this reason, it is assumed that the battery cell voltage value of each battery is unbalanced. When such an imbalance occurs, at the time of discharge, a cell having a relatively low voltage value is overdischarged, which may facilitate deterioration. Further, at the time of charging, a battery cell having a relatively high voltage value is overcharged, and there is a possibility that deterioration is easily promoted. Further, when the temperature of the battery becomes too high, there is a possibility that deterioration is easily promoted. Therefore, in order to cope with the acceleration of the deterioration of the battery, it is necessary to grasp the state of the battery at the time of charging / discharging, that is, the battery current value, the battery temperature, the battery cell voltage, and the like. Therefore, the battery state monitoring devices (W1 to W3) constituting the power supply device 1 monitor the state of the battery related to such charge / discharge (this value is referred to as “state value” in the present application). The battery current value, the battery temperature, and the battery cell voltage value are examples of state values.

  In order to suppress the deterioration promotion of each battery (Batt1 to Batt3) below a certain level, the state values such as the battery current value, the battery temperature, and the battery cell voltage value at the time of charging / discharging are within an allowable range (deterioration promotion is It can be said that it is desirable not to deviate from a range that can be kept below a certain level. As will be described below, the power supply device 1 performs charge / discharge control in consideration of this point.

[Power supply operation]
Power supply device 1 operates in accordance with external signal S so that battery block BB is selectively charged and discharged.

  This charge / discharge control policy is based on adjusting the charge current or discharge current according to the control value (value indicated by the external signal S), while suppressing the deterioration of each battery (Batt1 to Batt3). The charging current or the discharging current is suppressed as necessary so that the original performance of the power supply device 1 is continuously exhibited (a threshold value is set and is set to a state equal to or lower than the threshold value).

  More specifically, during charging, the current value of each battery, the temperature of each battery, and the voltage value of each battery cell do not deviate from the maximum allowable current value Imax1, the maximum allowable temperature Tmax1, and the maximum allowable voltage Vmax, respectively. To. In discharging, the current value of each battery, the temperature of each battery, and the voltage value of each battery cell are prevented from deviating from the maximum allowable current value Imax2, the maximum allowable temperature Tmax2, and the minimum allowable voltage Vmin, respectively. The “maximum allowable current value (Imax1, Imax2)”, “maximum allowable temperature (Tmax1, Tmax2)”, “maximum allowable voltage (Vmax)”, and “minimum allowable voltage (Vmin)” mentioned here are the present invention. This corresponds to the “predetermined allowable value”.

  Each of these permissible values (Imax1, Tmax1, Vmax, Imax2, Tmax2, Vmin) is specified as a limit value of a range in which battery deterioration promotion is suppressed (a range that is suppressed to a certain level or less). Note that the maximum allowable current values (Imax1, Imax2) during charging and discharging (hereinafter sometimes collectively referred to as “Imax”) may be the same value, and the maximum allowable temperatures during charging and discharging (Tmax1, Tmax2) (hereinafter sometimes collectively referred to as “Tmax”) may be the same value.

  Next, the flow of charge / discharge control of the battery block BB will be described more specifically with reference to the flowchart shown in FIG.

  The control device 11 determines whether charging or discharging is to be performed based on the external signal S (step S10), and if it is determined that charging is to be performed (“charging” in step S10), The operation of the charging mode described in (1) is executed.

  The control device 11 determines whether the current detection value Ibatt for any of the batteries has deviated (exceeded) the current limit value Ilim1 (step S11a). Here, the current limit value Ilim1 is set in advance as a value slightly smaller than the maximum allowable current value Imax1 (a value having a predetermined margin).

  Further, the control device 11 determines whether or not the voltage detection value Vbatt for any battery cell has deviated (exceeded) the voltage limit value Vlim1 (step S11b). Here, the voltage limit value Vlim1 is set in advance as a value slightly smaller than the maximum allowable voltage value Vmax (a value having a predetermined margin).

  Further, the control device 11 determines whether or not the temperature detection value Tbatt for any battery has deviated (exceeded) the temperature limit value Tlim1 (step S11c). Here, the temperature limit value Tlim1 is set in advance as a value slightly lower than the maximum allowable temperature Tmax1 (a value having a predetermined margin).

  Thus, the control device 11 determines whether or not the detection values (Ibatt, Vbatt, Tbatt) for each item deviate from the corresponding limit values (Ilim1, Vlim1, Tlim1). In addition, the order of each operation | movement (step S11a-S11c) mentioned above is not ask | required.

  Next, when none of the detected values deviates from the limit value (N in Step S12), the control device 11 determines whether or not the value of the charging current is smaller than the control value (Step S13). When the value of the charging current is not smaller than the control value (N in Step S13), the control device 11 repeats the operation in Step S10.

  When the value of the charging current is smaller than the control value (Y in step S13), the control device 11 increases the charging current (for example, increases the charging current by a predetermined amount). A command value is determined (step S14). Thereafter, the control device 11 sends information on the determined command value to the charge / discharge device 12 (step S17), and repeats the operation of step S10. As a result, the charging / discharging device 12 increases the charging current.

  On the other hand, if any detected value deviates from the limit value (Y in step S12), the control device 11 calculates the rate of change for the detected value that deviated from the limit value (step S15). .

More specifically, when the current detection value Ibatt for any battery deviates from the current limit value Ilim1, the control device 11 determines the change rate ΔI for the current detection value Ibatt, for example, Calculate according to equation (1).
ΔI = {(current detection value Ibatt) − (previous current detection value Ibatt)} / CI (1)
CI is a value set in advance as the width of the entire current range in which the battery operates.
For example, when CI is 50 A (the entire current range is 0 to 50 A), the current detection value Ibatt is 45 A, and the previous current detection value Ibatt is 40 A, the change rate ΔI is 0.1 according to the equation (1). Calculated.

Further, when the voltage detection value Vbatt for any one of the battery cells deviates from the voltage limit value Vlim1, the control device 11 sets the change rate ΔV for the voltage detection value Vbatt, for example, as in (2) Calculate according to the formula.
ΔV = | (current voltage detection value Vbatt) − (previous voltage detection value Vbatt) | / CV (2)
CV is a value set in advance as the width of the entire voltage range in which the battery cell operates.
For example, when the CV is 1V (the total voltage range is 3 to 4V), the current voltage detection value Vbatt is 3.9V, and the previous voltage detection value Vbatt is 3.7V, the change rate ΔV is expressed by the equation (2) as follows: Calculated as 0.2.

Further, when the temperature detection value Tbatt for any battery deviates from the temperature limit value Tlim1, the control device 11 sets the change rate ΔT for the temperature detection value Tbatt by, for example, the following equation (3): Calculate according to
ΔT = {(current temperature detection value Tbatt) − (previous temperature detection value Tbatt)} / CT (3)
CT is a value set in advance as the width of the entire temperature range in which the battery operates.
For example, when CT is 100 ° C. (the entire temperature range is −20 to 80 ° C.), the current temperature detection value Tbatt is 75 ° C., and the previous temperature detection value Tbatt is 60 ° C., the rate of change ΔT can be expressed by Equation (3). Is calculated to be 0.15.

  Then, the control device 11 determines a charging current command value so as to suppress the charging current in accordance with the largest change rate among the calculated change rates (ΔI, ΔV, ΔT) (step S16). More specifically, the control device 11 first determines the suppression amount of the charging current according to the largest change rate. As an example, the amount of suppression is determined to be a value obtained by multiplying the change rate by a predetermined coefficient so that it increases as the change rate increases. Further, the control device 11 determines a value obtained by subtracting the suppression amount from the current command value as a new command value.

  Thereafter, the control device 11 sends information on the determined command value to the charge / discharge device 12 (step S17), and repeats the operation of step S10. As a result, the charging / discharging device 12 reduces the charging current by the amount of the suppression amount (that is, according to the largest rate of change).

  Further, when it is determined in the operation of step S10 described above that the discharge should be performed ("discharge" of step S10), the control device 11 performs the operation in the discharge mode described below.

  The control device 11 determines whether the current detection value Ibatt for any of the batteries has deviated (exceeded) the current limit value Ilim2 (step S21a). Here, the current limit value Ilim2 is set in advance as a value slightly smaller than the maximum allowable current value Imax2 (a value having a predetermined margin).

  Further, the control device 11 determines whether or not the voltage detection value Vbatt for any battery cell has deviated (below) the voltage limit value Vlim2 (step S21b). Here, the voltage limit value Vlim2 is set in advance as a value (a value with a predetermined margin) slightly larger than the minimum allowable voltage value Vmin.

  Further, the control device 11 determines whether or not the temperature detection value Tbatt for any battery has deviated (exceeded) the temperature limit value Tlim2 (step S21c). Here, the temperature limit value Tlim2 is set in advance as a value slightly lower than the maximum allowable temperature Tmax2 (a value having a predetermined margin).

  In this way, the control device 11 determines whether or not the detection values (Ibatt, Vbatt, Tbatt) for each item have deviated from the corresponding limit values (Ilim2, Vlim2, Tlim2). In addition, the order of each operation | movement (step S21a-S21c) mentioned above is not ask | required.

  Next, when none of the detected values deviate from the limit value (N in Step S22), the control device 11 determines whether or not the value of the discharge current is smaller than the control value (Step S23). When the value of the discharge current is not smaller than the control value (N in Step S23), the control device 11 repeats the operation in Step S10.

  When the value of the discharge current is smaller than the control value (Y in Step S23), the control device 11 increases the discharge current (for example, increases the discharge current by a predetermined amount). A command value is determined (step S24). Thereafter, the control device 11 sends information on the determined command value to the charge / discharge device 12 (step S17), and repeats the operation of step S10. As a result, the charging / discharging device 12 increases the discharge current.

  On the other hand, if any of the detected values deviates from the limit value (Y in step S22), the control device 11 calculates a change rate for the detected value that deviates from the limit value (step S25). .

  More specifically, when the current detection value Ibatt for any battery deviates from the current limit value Ilim2, the control device 11 sets the change rate ΔI for this current detection value Ibatt, for example, as described above. Calculate according to equation (1). Further, when the voltage detection value Vbatt for any one of the battery cells deviates from the voltage limit value Vlim2, the control device 11 sets the change rate ΔV for the voltage detection value Vbatt, for example, as described above (2). Calculate according to the formula. Further, when the temperature detection value Tbatt for any battery deviates from the temperature limit value Tlim2, the control device 11 sets the change rate ΔT for the temperature detection value Tbatt, for example, the above-described equation (3) Calculate according to

  And the control apparatus 11 determines the command value of a discharge current so that a discharge current may be suppressed according to the largest change rate among each calculated change rate ((DELTA) I, (DELTA) V, (DELTA) T) (step S26). More specifically, the control device 11 first determines the amount of suppression of the discharge current according to the largest rate of change. As an example, the amount of suppression is determined to be a value obtained by multiplying the change rate by a predetermined coefficient so that it increases as the change rate increases. Further, the control device 11 determines a value obtained by subtracting the suppression amount from the current command value as a new command value.

  Thereafter, the control device 11 sends information on the determined command value to the charge / discharge device 12 (step S17), and repeats the operation of step S10. Thereby, the charging / discharging device 12 reduces the discharge current by the amount of the suppression amount (that is, according to the largest rate of change).

  In addition, about each change rate ((DELTA) I, (DELTA) V, (DELTA) T), it can be said that the amount of change per unit time is so large that the value is large, and it exists in the state which a detection value deviates easily from an allowable value. Therefore, in the charge / discharge control of the battery block BB, attention is paid to the largest change rate as described above, and the charge / discharge current is suppressed according to this change rate.

  That is, the charging / discharging current is suppressed so as not to deviate from the permissible value for an item most likely to deviate from the permissible value among the battery current value, the battery cell voltage value, and the battery temperature. Thus, the charge / discharge current can be suppressed efficiently so that any of the battery current value, the battery temperature, and the battery cell voltage value does not deviate from the allowable value.

  Next, the state change of each item at the time of suppression of charging / discharging current is demonstrated below, referring each graph shown in FIGS. In this description, the current limit values (Ilim1, Ilim2) during charging and discharging are collectively referred to as “Ilim”. Further, the limiting temperatures (Tlim1, Tlim2) during charging and discharging are collectively referred to as “Tlim”.

  FIG. 3 shows that when charging / discharging, when the current value of one of the batteries (referred to as “target battery” for convenience) deviates from the current limit value Ilim, the charging / discharging current is suppressed so as to eliminate this deviation. The graph is shown as an example. In the graph, the horizontal axis represents time, and the vertical axis represents the current value. The graph also shows the state of the charge / discharge current command value, the current value of the specific battery, and the current value of other batteries.

  When the current value of the target battery gradually increases and deviates from the current limit value Ilim, the charge / discharge current command value that the control device 11 gives to the charge / discharge device 12 is reduced. In the example of FIG. 3, the command value is decreased at the timing Ta. As a result, the charging / discharging current is suppressed, and the current value of each battery is suppressed accordingly. As a result, the current value of the battery of interest is a value that does not deviate from the current limit value Ilim. As described above, the current value of the battery of interest is suppressed every time it deviates from the current limit value Ilim so as not to exceed the maximum allowable current value Imax.

  FIG. 4 shows that during charging, when the voltage value of any battery cell (referred to as “target battery cell” for convenience) deviates from the voltage limit value Vlim1, the charging current is suppressed so as to eliminate this deviation. The graph in the case where it is done is illustrated. In the graph, the horizontal axis represents time, and the vertical axis represents a current value or a voltage value. The graph also shows the state of the charging current command value, the voltage value of the target battery cell, and the voltage values of other battery cells provided in the battery having the target battery cell.

  When the voltage value of the target battery cell gradually increases and deviates from the voltage limit value Vlim1, the command value of the charging current that the control device 11 gives to the charging / discharging device 12 is reduced. In the example of FIG. 4, the command value is decreased at the timing Tb. As a result, the charging current is suppressed, and the voltage value of each battery cell is suppressed accordingly. As a result, the voltage value of the battery cell of interest becomes a value that does not deviate from the voltage limit value Vlim1. As described above, the voltage value of the target battery cell is suppressed every time it deviates from the voltage limit value Vlim1 so as not to exceed the maximum allowable voltage value Vmax.

  FIG. 5 exemplifies a graph when the discharge current is suppressed so as to eliminate this deviation when the voltage value of any battery cell (target battery cell) deviates from the voltage limit value Vlim2 during discharging. ing. In the graph, the horizontal axis represents time, and the vertical axis represents a current value or a voltage value. The graph also shows the state of the discharge current command value, the voltage value of the target battery cell, and the voltage values of other battery cells provided in the battery having the target battery cell.

  When the voltage value of the battery cell of interest gradually decreases and deviates from the voltage limit value Vlim2, the command value of the discharge current that the control device 11 gives to the charge / discharge device 12 is reduced. In the example of FIG. 5, the command value is decreased at the timing Tc. As a result, the discharge current is suppressed, and the voltage value of each battery cell is increased accordingly. As a result, the voltage value of the target battery cell is a value that does not deviate from the voltage limit value Vlim2. As described above, the voltage value of the battery cell of interest is raised every time it deviates from the voltage limit value Vlim2 so as not to fall below the minimum allowable voltage value Vmin.

  FIG. 6 exemplifies a graph in the case where the charge / discharge current is suppressed so as to eliminate this deviation when the temperature of any battery (the battery of interest) deviates from the temperature limit value Tlim during charge / discharge. Yes. In the graph, the horizontal axis represents time, and the vertical axis represents current value or temperature. In addition, the graph shows the charge / discharge current command value, the temperature of the battery of interest, and the temperature of other batteries.

  When the temperature of the battery of interest gradually rises and deviates from the temperature limit value Tlim, the charge / discharge current command value that the control device 11 gives to the charge / discharge device 12 is reduced. In the example of FIG. 6, the command value is made small at timing Td. Thereby, the charge / discharge current is suppressed, and the temperature of each battery is lowered accordingly. As a result, the temperature of the battery of interest becomes a value that does not deviate from the temperature limit value Tlim. Thus, the temperature of the battery of interest is lowered every time it deviates from the temperature limit value Tlim so as not to exceed the maximum allowable temperature Tmax.

  In the present embodiment, three values of a battery current value, a battery temperature, and a battery cell voltage value are set as values (state values) that do not deviate from the allowable values. However, as a modification of the present embodiment, any one or two of these may be excluded from values that do not deviate from the allowable value. For example, excluding “battery temperature” and “battery cell voltage value”, only “battery current value” can be set as a value that does not deviate from the allowable value.

  When the “battery current value” is excluded, the operations of steps S11a and S21a described above are unnecessary in the charge / discharge control, and can be omitted. Further, when “the voltage value of the battery cell” is excluded, in the charge / discharge control, the operations in steps S11b and S21b described above are unnecessary and can be omitted. When “battery temperature” is excluded, the operations in steps S11c and S21c described above are unnecessary in charge / discharge control, and can be omitted.

  By the way, regarding the conventional example described above (see FIG. 12), FIG. 13 shows a charge / discharge current in the case where the battery arm C (corresponding to the “battery unit” in the present embodiment) C in which an abnormality has occurred is disconnected. The graph of a value (total of the current value of each battery arm) and the current value of each battery arm is illustrated. In FIG. 13, the horizontal axis indicates time, and the vertical axis indicates current value. The timing t1 represents the timing when the battery arm C is disconnected, and the timing t2 represents the timing when the charge / discharge current is reduced in order to suppress an increase in the burden on the other battery arms.

  As shown in FIG. 13, when the timing t1 is passed, the battery arm C is already disconnected, but the charging / discharging current value is disconnected until the timing t2 arrives. The previous state is maintained. Therefore, the current values of the other battery arms (battery arms A and B) increase during the period from timing t1 to t2. This increases the burden on the other battery arms and may accelerate the deterioration.

  However, according to the power storage device 2 according to the present embodiment, since the battery unit is not separated, the deterioration is not accelerated by such factors, and the performance of the original power supply device 1 (whichever The performance in a state where the battery unit is not lacking can be continuously exhibited. Therefore, according to the power storage device 2, it is possible to continuously exhibit the original performance of the power supply device 1 while suppressing the deterioration of the battery during charging and discharging.

  As described above, the power storage device 2 controls charging / discharging so that the state value does not deviate from the allowable value. Therefore, when at least one of the state values is the current value of the battery, it is possible to suppress deterioration caused by the battery current during charging and discharging. Further, since at least one of the state values is the temperature of the battery, it is possible to suppress deterioration caused by the temperature of the battery during charging and discharging. In addition, since at least one of the state values is the voltage value of the battery cell, it is possible to suppress deterioration caused by the voltage of the battery cell during charging and discharging.

  In addition, about the form of control of charging / discharging, instead of the form which controls the value of charging / discharging electric current, the value of charging / discharging electric power calculated | required by multiplying the voltage value of a battery to the sum total (charging / discharging electric current) of each battery Even if a form for controlling the above is adopted, the same effect as in the present embodiment can be obtained.

2. Second Embodiment Next, a second embodiment will be described. In the following description, points different from the first embodiment are emphasized, and description of common points may be omitted.

  As described so far, according to the power supply device 1 of the first embodiment, the charging / discharging current is controlled so that the battery current, the battery temperature, and the battery cell voltage do not deviate from the allowable ranges. It is possible to continuously exhibit the original performance of the power supply device 1 while suppressing the deterioration promotion of Batt1 to Batt3).

  However, when the battery temperature or the battery cell voltage does not deviate from the allowable range, the upper limit of the allowable charge / discharge current is the battery with the most severe deterioration (that is, the temperature or battery cell voltage at the time of charge / discharge). , Which is most likely to deviate from the allowable range). Therefore, for example, when some of the batteries are extremely deteriorated, there is a concern that the charge / discharge current as the power supply device 1 is significantly limited regardless of the degree of deterioration of the other batteries.

  In such a case, there is a case where the upper limit of the allowable charge / discharge current becomes higher when the battery with severe deterioration is separated from the battery block BB. Therefore, as described below, the power supply device according to the second embodiment performs such disconnection when it is estimated that the upper limit of the allowable charge / discharge current is higher when the battery with severe deterioration is disconnected. The operation (hereinafter referred to as “upper limit optimization operation” for convenience) is performed. Hereinafter, the configuration and the like of the power supply device according to the second embodiment will be described in more detail.

  FIG. 7 is a configuration diagram of the power supply device according to the present embodiment. As shown in the figure, the power supply device 1 includes a battery unit (BU1 to BU3), a control device 11, and a charge / discharge device 12 as in the case of the first embodiment, and further includes a switch (SW1 to SW1). SW3).

  Each switch (SW1 to SW3) is provided in series with the corresponding battery (Batt1 to Batt3), and is opened and closed in accordance with an instruction from the control device 11. When the switch is closed, the corresponding battery is connected to the battery block BB (functions as a part of the battery block BB), but when the switch is opened, the corresponding battery is disconnected from the battery block BB. . Each switch is set to the closed state in the initial state.

  In this embodiment, each switch is provided outside the battery unit (BU1 to BU3), but may be provided inside the battery unit. In this case, the control device 11 is configured to issue an instruction to open the switch to the battery state monitoring devices (W1 to W3). Upon receiving the instruction, the battery state monitoring device opens the switch in its battery unit.

  Next, the flow of charge / discharge control of the battery block BB will be described more specifically with reference to the flowchart shown in FIG. In addition, the content of the charge / discharge control in this embodiment is that step S15 ′, S25 ′, and new operations of S31 to S34 are added, and instead of the operations of steps S16 and S26, step S16-1 , S16-2, S26-1, and S26-2 are the same as the charge / discharge control in the first embodiment except that the operations are performed. Hereinafter, description of operations equivalent to those of the first embodiment will be omitted.

  In the present embodiment, when the rate of change (ΔI, ΔV, ΔT) for the detected value that deviates from the limit value is calculated during charging (step S15), the control device 11 includes the following calculation results: It is determined whether the rate of change ΔI for the current is maximum (step S15 ′). If the rate of change ΔI is maximum (Y in step S15 ′), the control device 11 determines a command value so as to suppress the charging current according to the rate of change ΔI (step S16-1).

  On the other hand, when the rate of change ΔI is not maximum (that is, when the rate of change ΔV for voltage or the rate of change ΔT for temperature is maximum) (N in step S15 ′), the upper limit optimization operation is performed. It is executed (step S31). As a result of the operation, when a deteriorated battery (described in detail later) is disconnected from the battery block BB (Y in step S32), the process returns to the operation in step S10. On the other hand, when the deteriorated battery is not disconnected from the battery block BB (N in Step S32), the control device 11 determines another change rate (that is, the change rate ΔV and the change rate) excluding the change rate ΔI for the current. The command value is determined so as to suppress the charging current according to the maximum rate of change in the rate ΔT) (step S16-2). In addition, after the operation of step S16-1 or S16-2 is performed, the operation of step S17 is performed.

  Further, at the time of discharging, when the rate of change (ΔI, ΔV, ΔT) for the detected value that deviates from the limit value is calculated (step S25), the control device 11 determines the current among the calculated results. It is determined whether the change rate ΔI of the maximum is (step S25 ′). If the rate of change ΔI is maximum (Y in step S25 ′), the control device 11 determines a command value so as to suppress the discharge current according to the rate of change ΔI (step S26-1).

  On the other hand, when the change rate ΔI is not the maximum (that is, when the change rate ΔV for the voltage or the change rate ΔT for the temperature is the maximum) (N in step S25 ′), the upper limit optimization operation is performed. It is executed (step S33). As a result of the operation, when the deteriorated battery is disconnected from the battery block BB (Y in step S34), the process returns to the operation in step S10. On the other hand, when the deteriorated battery is not disconnected from the battery block BB (N in step S34), the control device 11 determines other change rates (that is, the change rate ΔV and the change rate) excluding the change rate ΔI for the current. The command value is determined so as to suppress the discharge current according to the maximum rate of change in the rate ΔT) (step S26-2). In addition, after the operation of step S26-1 or S26-2 is performed, the operation of step S17 is performed.

  Next, specific contents of the above-described upper limit optimization operation (steps S31 and S33) will be described with reference to the flowchart shown in FIG. First, the control device 10 identifies a battery whose detected value deviates from the limit value as a deteriorated battery (a battery that is considered to be the most deteriorated) (step S51). Then, control device 10 determines whether the upper limit of the allowable charge / discharge current is higher when the deteriorated battery is disconnected from battery block BB than when it is not disconnected (that is, the current state) (step S52). .

  As a normal tendency, the larger the characteristic difference between the deteriorated battery and other batteries, the higher the upper limit of charge / discharge current allowed when the deteriorated battery is disconnected. In other words, when the temperature of the deteriorated battery and the cell voltage at the time of charging are extremely large compared to other batteries, or when the cell voltage at the time of discharge of the deteriorated battery is extremely small compared to other batteries, the deterioration occurs. It is expected that the upper limit of the charge / discharge current allowed when the battery is disconnected will be higher.

  Therefore, in the operation of step S52, as an example, when the difference between the detected value (state value) of the deteriorated battery and the detected value (state value) of another battery deviates from a predetermined reference range, the deteriorated battery is disconnected. It may be determined that the upper limit of the charge / discharge current allowed is higher. That is, for example, when the temperature detection value Tbatt of the deteriorated battery deviates from the limit temperature Tlim, the difference between the temperature detection value Tbatt of the deteriorated battery and the temperature detection value Tbatt of another battery is calculated, and this difference is the reference range. When the value deviates from the above, it is determined that the upper limit of the allowable charge / discharge current is higher when the deteriorated battery is disconnected. Note that the reference range is determined in advance so as to be appropriately determined. Here, the case where the detected value of the temperature of the deteriorated battery deviates from the limit value is taken as an example, but the same applies to the case where the detected value of the cell voltage deviates from the limit value.

  When the controller 10 determines that the upper limit of the charge / discharge current allowed is higher when the deteriorated battery is disconnected (Y in step S52), the control device 10 switches the switch corresponding to the deteriorated battery to the open state, and sets the battery block BB. The deteriorated battery is disconnected from (Step S53). This completes the upper limit optimization operation. If it is determined that the upper limit of the allowable charge / discharge current does not increase (N in step S52), the upper limit optimization operation is completed without disconnecting the deteriorated battery.

  As is clear from the above description, the control device 11 according to the present embodiment includes a functional unit (one form of the deteriorated battery specifying unit) that specifies a battery whose state value deviates from the limit value as a deteriorated battery, and a deteriorated battery. Is formed as a function unit (one form of the determination unit) for determining whether or not the upper limit of the charge / discharge current allowed when the battery block BB is separated from the battery block BB is higher than the current state. Further, the switches (SW1 to SW3) are deteriorated according to an instruction from the control device 11 or the like (when it is determined that the upper limit of the charge / discharge current allowed when the deteriorated battery is disconnected is higher than the current state). A functional part (one form of the switch part) for separating the battery from the battery block BB is formed.

  As described above, the power storage device 2 according to the present embodiment performs the upper limit optimization operation. Therefore, it is possible to disconnect a battery with severe deterioration from the battery block BB in accordance with the determination result and maintain (optimize) the upper limit of the allowable charge / discharge current as high as possible.

  In addition, about the form of control of charging / discharging, instead of the form which controls the value of charging / discharging electric current, the value of charging / discharging electric power calculated | required by multiplying the voltage value of a battery to the sum total (charging / discharging electric current) of each battery Even if a form for controlling the above is adopted, the same effect as in the present embodiment can be obtained.

3. Third Embodiment Next, a third embodiment will be described. In the following description, points different from the first embodiment are emphasized, and description of common points may be omitted.

  As described above, the rise in battery temperature is a factor in accelerating battery deterioration. Therefore, the power supply device 1 according to the present embodiment has the same configuration as that of the first embodiment (see FIG. 1), but the charge / discharge control is performed according to the temperature of the battery. The upper limit is limited. Hereinafter, charge / discharge control performed by the power supply device of the third embodiment will be described with reference to the flowchart shown in FIG. The contents of the charge / discharge control in the present embodiment are the same as the contents of the charge / discharge control in the first embodiment, except that new operations in steps S61 and S62 are added.

  As in the case of the first embodiment, the control device 11 determines whether charging or discharging is to be performed based on the external signal S (step S10), and if it is determined that charging is to be performed ( In step S10 ("charging"), the operation of the charging mode described next is executed.

  First, the control device 11 determines the upper limit value of the charging current according to the temperature of the battery (step S61). More specifically, the current limit value Ilim1 at the time of charging is determined so as to become a smaller value as the battery temperature increases in accordance with a predetermined determination condition. Here, for example, an average value or a maximum value of the temperature detection values Tbatt of the respective batteries can be regarded as the battery temperature.

  Then, the control apparatus 11 performs operation | movement of step S11a. Since the subsequent operations are the same as those in the first embodiment, description thereof is omitted here.

  Further, when it is determined in the operation of step S10 described above that the discharge should be performed ("discharge" of step S10), the control device 11 performs the operation in the discharge mode described below.

  First, the control device 11 determines the upper limit value of the discharge current according to the temperature of the battery (step S62). More specifically, the current limit value Ilim2 at the time of discharging is determined so as to become a smaller value as the battery temperature increases in accordance with a predetermined determination condition. Also here, for example, the average value or the maximum value of the temperature detection values Tbatt of the respective batteries can be regarded as the battery temperature.

  Then, the control apparatus 11 performs operation | movement of step S21a. Since the subsequent operations are the same as those in the first embodiment, description thereof is omitted here.

  FIG. 11 illustrates a graph of the upper limit value of the charge / discharge current. As shown in the figure, the upper limit value of the charge / discharge current is dynamically adjusted so as to become smaller as the battery temperature increases. In the present embodiment, the upper limit of the charge / discharge current is limited to the upper limit value set according to the battery temperature in this way. Thus, according to the power storage device 2 according to the present embodiment, the battery temperature is prevented from becoming excessively high, and the original performance of the power supply device 1 is continuously exhibited while suppressing the deterioration of the battery. It is possible to make it.

  In addition, about the form of control of charging / discharging, instead of the form which controls the value of charging / discharging electric current, the value of charging / discharging electric power calculated | required by multiplying the voltage value of a battery to the sum total (charging / discharging electric current) of each battery Even if a form for controlling the above is adopted, the same effect as in the present embodiment can be obtained.

4). Others The power device 1 according to each embodiment includes a power storage device 2 having a function of storing power using the battery block BB, and a charge / discharge device that performs charge / discharge of the battery block BB in accordance with control by the control device 11. It can also be seen that 12 is provided.

  The power storage device 2 according to the first embodiment and the second embodiment includes a battery block BB formed by connecting a plurality of batteries (Batt1 to Batt3) in parallel, and a state value for each of the plurality of batteries. Battery state monitoring devices (W1 to W3) for monitoring (battery current value, battery temperature, battery cell voltage value) and the state values of each of these batteries do not deviate from a predetermined allowable value. And a control device 11 that controls charging and discharging of the battery block BB.

  The power storage device 2 is a device that controls charging / discharging of the battery block BB. For each of a plurality of batteries (Batt1 to Batt3), a battery state monitoring device (W1 to W3) that monitors a state value, and a plurality of batteries It can be seen that each battery has a monitoring control device including a control device 11 that controls charging / discharging so that the state value does not deviate from a predetermined allowable value. Further, the control device 11 is regarded as a device that controls charging / discharging of the battery by receiving information used for charging / discharging control that prevents the state value from deviating from the allowable value as a device that controls charging / discharging of the battery block BB. be able to.

  The power storage device 2 according to the third embodiment includes a battery block BB formed by connecting a plurality of batteries (Batt1 to Batt3) in parallel, and a state value (battery current) for each of the plurality of batteries. A battery state monitoring device (W1 to W3) that monitors a value, a battery temperature, and a battery cell voltage value), and a control device 11 that controls charging and discharging of the battery block BB. The upper limit of the charge / discharge current is limited to an upper limit value set according to the battery temperature.

  Further, the power supply device 1 according to each embodiment monitors the state value of each of the plurality of batteries and the battery block BB formed by connecting a plurality of batteries (Batt1 to Batt3) in parallel, and the result of the monitoring is obtained. A battery unit including a battery state monitoring device (W1 to W3) that creates information to be used as information used for charge / discharge control of the battery block BB (control to prevent the state value from deviating from the allowable value) You can see that you are doing.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this content. The embodiments of the present invention can be variously modified without departing from the gist of the present invention. As an example, instead of the battery block BB, a single battery or a battery in which a plurality of batteries are connected in series may be used. In addition, the determination method of the deviation of the allowable value is not limited to the determination method based on the comparison with the threshold value as in the above embodiment, and various types of determination methods can be adopted. As an example, a method of determining whether or not the allowable value is deviated based on the current value and the change rate may be employed.

  The present invention can be used for a power supply device using a battery.

DESCRIPTION OF SYMBOLS 1 Power supply device 2 Power storage device 11 Control device 12 Charging / discharging device Batt1, Batt2, Batt3 Battery BB Battery block BC Battery cell BU1, BU2, BU3 Battery unit SW1, SW2, SW3 Switch W1, W2, W3 Battery state monitoring device

Claims (11)

A battery unit having at least one battery;
For the battery, one or a plurality of items, a monitoring unit that monitors a state value that is a state value of the battery related to charging and discharging
A control unit that controls charging and discharging of the battery unit so that the state value of the battery does not deviate from a predetermined allowable value;
A power storage device comprising: At least one of the state values is a current value of the battery,
The controller is
The power storage device according to claim 1, wherein the charging / discharging of the battery is controlled so that the current value does not deviate from the allowable value. At least one of the state values is a temperature of the battery;
The controller is
The power storage device according to claim 1, wherein the charging / discharging of the battery is controlled so that the temperature does not deviate from the allowable value. At least one of the state values is a voltage value of a battery cell included in the battery,
The control unit, for the battery,
Control the charging of the battery unit so that the voltage does not deviate from the upper tolerance.
The power storage device according to claim 1, wherein discharging of the battery unit is controlled so that the voltage does not deviate from the lower allowable value. The controller is
The charging / discharging current or the charging / discharging power is suppressed when the state value deviates from a limit value set in accordance with the permissible value. The power storage device described. The state value is at least the temperature of the battery or the voltage value of the battery cell that the battery has,
A deteriorated battery specifying unit for specifying, as a deteriorated battery, a battery whose state value deviates from the limit value;
A determination unit for determining whether the charge / discharge current allowed when the deteriorated battery is disconnected from the battery unit, or whether the upper limit of charge / discharge power is higher than the current state;
A switch unit that disconnects the deteriorated battery from the battery unit when it is determined to be higher than the current state;
The power storage device according to claim 5, further comprising: The discrimination unit
The determination is performed by determining whether or not a difference between a state value of the deteriorated battery and another state value of the battery deviates from a predetermined reference range. Power storage device. A battery unit having at least one battery;
A monitoring unit for monitoring the temperature of the battery;
A charge / discharge current of the battery unit, or a control unit for controlling charge / discharge power,
The controller is
The power storage device, wherein an upper limit of the charge / discharge current or charge / discharge power is limited to an upper limit value set according to a temperature of the battery. The power storage device according to any one of claims 1 to 8,
In accordance with control related to charging or discharging by the control unit, a charging / discharging device that performs charging / discharging of the battery unit;
A power supply device comprising: A battery unit having at least one battery;
Regarding the battery, one or a plurality of items, which are state values that are values of the state of the battery relating to charging / discharging, are monitored, and information indicating the result of the monitoring is determined so that the value of the state of the battery relating to charging / discharging does not deviate from the allowable value. A monitoring unit to be created as information used for charge / discharge control of the battery unit,
A battery unit comprising: An apparatus for controlling charging / discharging of a battery,
A control device that controls charging / discharging of the battery in response to information used for charging / discharging control that prevents a state value that is a state value of the battery relating to charging / discharging from deviating from an allowable value.

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