JP2011109910A - Charge/discharge controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charge/discharge controller by which charging/discharging control is performed according to a degree of deterioration of each separated electric condenser. <P>SOLUTION: The charge/discharge controller performs the charging/discharging control of a plurality of electric storage portions for supplying and receiving electric power between electric working elements to be electrically driven, and includes: a deterioration degree detector to detect the degree of deterioration of each of the plurality of electric storage portions; and an adjusting portion to adjust the degree of cooling or degree of charging in at least one of the plurality of electric storage portions, based on a detection result of the deterioration degree detector. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a charge / discharge control device for a battery that is repeatedly charged and discharged.

  An example of a capacitor used as a secondary battery is a capacitor that electrostatically stores or discharges charges. The capacitor accumulates or discharges electric energy by repeatedly charging and discharging according to the demand of the load.

  Such a capacitor is variously designed to increase the capacity so that power can be supplied to and recovered from a load with a large rated output, such as an electric motor of a vehicle or work machine. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 10-125559

  By the way, an increase in capacity of a capacitor accompanies an increase in size, and the storage capacitor of the enlarged capacitor is limited. Therefore, it is conceivable to divide the capacitor.

  However, when the capacitors are divided, the degree of deterioration of the divided capacitors may vary depending on the installation environment.

  In such a case, if charging / discharging of the divided capacitors is performed at once, there is a problem that the degree of deterioration of the capacitor that has progressed further deteriorates, or a problem that the overall charging efficiency decreases. It was.

  Therefore, an object of the present invention is to provide a charge / discharge control device having a function of performing charge / discharge control according to the degree of deterioration of each of the divided capacitors and leveling the degree of deterioration.

  A charge / discharge control device according to one aspect of the present invention is a charge / discharge control device that performs charge / discharge control of a plurality of power storage units that exchange electric power with an electrically driven electric work element. A deterioration degree detection unit that detects the degree of deterioration of each of the units, and an adjustment unit that adjusts the charge degree of at least one of the plurality of power storage units based on the detection result of the deterioration degree detection unit, The adjustment unit adjusts the charge degree based on internal resistance values or capacitance values of the plurality of power storage units.

  In addition, when there is a variation in the deterioration levels of the plurality of power storage units detected by the deterioration level detection unit, the adjustment unit may decrease the charge level of the power storage unit having a high deterioration level.

  The adjusting unit adjusts the charging degree by adjusting an upper limit value of a charging voltage of at least one power storage unit when each of the plurality of power storage units is connected in series. May be.

  The adjusting unit may adjust the charge degree by adjusting a charge / discharge current value of at least one power storage unit when each of the plurality of power storage units is connected in parallel to each other. Also good.

  According to the present invention, it is possible to provide a charge / discharge control device having a function of performing charge / discharge control according to the degree of deterioration of each of the divided capacitors and leveling the degree of progress of deterioration.

It is a figure which shows the electric power control circuit in which charging / discharging control is performed by the charging / discharging control apparatus of Embodiment 1. FIG. It is a figure which shows the structure of the battery 19 which performs charging / discharging control with the charging / discharging control apparatus of Embodiment 1, (a) is a whole block diagram, (b) is a figure which shows the circuit structure of a battery module. FIG. 4 is a diagram for explaining a measurement principle when measuring the degree of deterioration of each battery module in the charge / discharge control device according to the first embodiment, in which charging voltage is measured over time when measuring an internal resistance value and a capacitance value; It is a characteristic view showing a change. In the charge / discharge control apparatus of Embodiment 1, it is a figure for demonstrating the measurement principle at the time of measuring the deterioration degree of each battery module, (a) is a concept showing the judgment method of the deterioration degree based on an internal resistance value FIG. 4B is a conceptual diagram showing a method for determining the degree of deterioration based on the capacitance value. It is a figure which shows the process sequence of the charge degree change process by the charging / discharging control apparatus of Embodiment 1. FIG. It is a figure which shows the structure of the buck-boost converter and battery which perform charging / discharging control with the charging / discharging control apparatus of Embodiment 2. FIG. It is a figure which shows the process sequence of the charge degree change process by the charging / discharging control apparatus of Embodiment 2. FIG. It is a figure which shows the process sequence of the charge degree change process by the charging / discharging control apparatus of Embodiment 3. FIG.

  Embodiments to which the charge / discharge control device of the present invention is applied will be described below.

[Embodiment 1]
FIG. 1 is a diagram illustrating a power control circuit in which charge / discharge control is performed by the charge / discharge control device of the first embodiment. The power control circuit includes a buck-boost converter 100, a DC bus 110, an electric drive unit 112, and a battery 19. The battery 19 is a battery that includes a capacitance component whose charge voltage value is measured by the charge / discharge control device of the first embodiment.

  The step-up / down converter 100 includes a reactor 101, a boosting IGBT (Insulated Gate Bipolar Transistor) 102 </ b> A, a step-down IGBT 102 </ b> B, a power connection terminal 103 for connecting a battery 19, an output terminal 104 for connecting an electric drive unit 112, and a pair. A smoothing capacitor 105, a battery voltage detection unit 106, and a battery current detection unit 107 that are inserted in parallel with the output terminal 104.

  The output terminal 104 of the step-up / down converter 100 and the electric drive unit 112 are connected by a DC bus 110.

  Reactor 101 has one end connected to an intermediate point between boosting IGBT 102A and step-down IGBT 102B, and the other end connected to power supply connection terminal 103, so that induced electromotive force generated when ON / OFF of boosting IGBT 102A is generated. It is provided for supplying to the DC bus 110.

  The step-up IGBT 102 </ b> A and the step-down IGBT 102 </ b> B are semiconductor elements that are configured by a bipolar transistor in which a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is incorporated in a gate portion and can perform high-power high-speed switching. The step-up IGBT 102A and the step-down IGBT 102B are driven by applying a PWM voltage from the drive control unit 120 to the gate terminal. Diodes 102a and 102b, which are rectifier elements, are connected in parallel to the step-up IGBT 102A and the step-down IGBT 102B.

  Here, drive control (charge / discharge switching control) of the step-up IGBT 102 </ b> A and the step-down IGBT 102 </ b> B is performed by the drive control unit 120. For this reason, in the drive control unit 120, switching between charge and discharge by the boosting IGBT 102A and the step-down IGBT 102B is detected.

  Here, the term “switching between charge and discharge” refers to switching from a discharging state to a charging state, switching from a charging state to a discharging state, or switching from a state where charging / discharging is not performed to a charging state or discharging state. Is used to represent.

  The battery 19 may be a chargeable / dischargeable battery so that power can be exchanged with the DC bus 110 via the buck-boost converter 100. The battery 19 includes a plurality of power storage units, and is configured such that each of the plurality of power storage units can be disposed at different locations. Details of the configuration of the battery 19 will be described later with reference to FIG.

  The power connection terminal 103 and the output terminal 104 may be terminals that can be connected to the battery 19 and the electric drive unit 112. A battery voltage detection unit 106 that detects a battery voltage is connected between the pair of power connection terminals 103. A DC bus voltage detector 111 that detects a DC bus voltage is connected between the pair of output terminals 104.

  The battery voltage detection unit 106 detects the voltage value Vm (voltage between terminals) of the battery 19, and the DC bus voltage detection unit 111 detects the voltage of the DC bus 110 (hereinafter, DC bus voltage Vdc).

  The electric drive unit 112 that is a load connected to the output terminal 104 may include an electric motor capable of power running operation and regenerative operation. As such an electric motor, for example, an IPM (Interior) in which a magnet is embedded in a rotor is used. Permanent Magnetic) motor can be used.

  The smoothing capacitor 105 may be any storage element that is inserted between the positive terminal and the negative terminal of the output terminal 104 and can smooth the DC bus voltage.

  The battery current detection unit 107 may be any detection means capable of detecting the value of the current flowing through the battery 19 and includes a current detection resistor. The battery current detection unit 107 detects a current value I flowing through the battery 19.

  In the first embodiment, the current value in the direction in which current is supplied from battery 19 to DC bus 110 is positive, and the current value in the direction in which current is supplied from DC bus 110 to battery 19 is negative. That is, the current value when discharging the battery 19 is positive, and the current value when charging the battery 19 is negative.

"Buck-boost operation"
In such a step-up / down converter 100, when boosting the DC bus 110, a PWM voltage is applied to the gate terminal of the boosting IGBT 102A, and the boosting IGBT 102A is connected via the diode 102b connected in parallel to the step-down IGBT 102B. The induced electromotive force generated in the reactor 101 when the power is turned on / off is supplied to the DC bus 110. Thereby, the DC bus 110 is boosted.

  When the DC bus 110 is stepped down, a PWM voltage is applied to the gate terminal of the step-down IGBT 102B, and the regenerative power generated by the electric drive unit 112 is transferred from the DC bus 110 to the battery 19 via the step-down IGBT 102B. Supply. As a result, the power stored in the DC bus 110 is charged in the battery 19 and the DC bus 110 is stepped down.

  FIG. 2 is a diagram illustrating a configuration of a battery 19 that performs charge / discharge control by the charge / discharge control device according to the first embodiment. FIG. 2A is an overall configuration diagram and FIG. 2B is a diagram illustrating a circuit configuration of a battery module. It is.

  As shown in FIG. 2A, the battery 19 as a battery actually includes battery modules 19-1 to 19-n as a plurality of power storage units.

  The battery modules 19-1 to 19-n (n is an integer of 2 or more) are all connected in series, but the casings are separated so that each can be installed in a separate place.

  Battery modules 19-1 to 19-n include battery cells connected in series to each other. Thus, the battery modules 19-1 to 19-n include a plurality of battery cells connected in parallel, and the battery modules 19-1 to 19-n are connected in series to constitute the battery 19.

  The battery modules 19-1 to 19-n include electric fans 19A-1 to 19A-n as cooling devices, respectively. The electric fans 19A-1 to 19A-n are supplied with electric power from the battery modules 19-1 to 19-n and are driven by the drive control unit 120, respectively.

  The module voltage detectors 130-1 to 130-n are connected to the battery modules 19-1 to 19-n, respectively. Electric signals representing the battery voltage values of the battery modules 19-1 to 19-n detected by the module voltage detection units 130-1 to 130-n are input to the drive control unit 120.

  Further, as shown in FIG. 2B, the battery modules 19-1 to 19-n include battery units 19B-1 to 19B-n, bypass circuits 19C-1 to 19C-n, and a changeover switch 19D-, respectively. 1-19D-n. The changeover switches 19D-1 to 19D-n are disposed in front of and behind the battery units 19B-1 to 19B-n. Here, the changeover switches 19D-1 to 19D-n do not necessarily have to be provided at two positions on the front and rear sides, and either one may be provided. The bypass circuits 19C-1 to 19C-n may be installed in units of battery cells smaller than the unit of battery modules.

  The battery units 19B-1 to 19B-n are parts that accumulate electric power inside the batteries 19-1 to 19-n, respectively.

  The bypass circuits 19C-1 to 19C-n are circuits that are used to lower the voltages of the battery units 19B-1 to 19B-n to a predetermined voltage value within a set time, and the changeover switch 19D-1 Switching of ˜19D-n is performed by the drive control unit 120.

  Note that the changeover switches 19D-1 to 19D-n are normally connected to positions where the battery units 19B-1 to 19B-n can be charged and discharged as shown in FIG. Only, the drive control unit 120 switches to the bypass circuits 19C-1 to 19C-n. Switching control of the changeover switches 19D-1 to 19D-n will be described later.

  Note that here, the battery 19 is shown as a capacitor, but instead of the battery 19, a capacitor, a chargeable / dischargeable secondary battery, or another form of power supply capable of power transfer may be used as the capacitor.

  FIG. 3 is a diagram for explaining the measurement principle when measuring the degree of deterioration of each battery module in the charge / discharge control device of the first embodiment, when measuring the internal resistance value and the capacitance value. It is a characteristic view showing the time-dependent change of charging voltage.

  FIG. 4 is a diagram for explaining a measurement principle when measuring the deterioration degree of each battery module in the charge / discharge control device of the first embodiment, and FIG. 4A is a determination of the deterioration degree based on the internal resistance value. The conceptual diagram showing a method, (b) is a conceptual diagram showing the judgment method of the deterioration degree based on an electrostatic capacitance value.

  The measurement of the degree of deterioration and the adjustment of the degree of charge are processes executed by the drive control unit 120 as the deterioration degree detection unit and the adjustment unit for the battery modules 19-1 to 19-n.

  Moreover, since all the measurement processes of the deterioration degree performed with respect to the battery modules 19-1 to 19-n are the same, the case where the deterioration degree of the battery module 19-1 is measured is demonstrated here. The degree of deterioration is determined by the amount of change in the internal resistance or capacitance of the battery module.

  As shown in FIG. 3, no battery current flows through the battery module 19-1 at time t = 0. For this reason, the battery current value detected by the battery current detection unit 107 is zero, and the charging voltage value detected by the module voltage detection unit 130-1 is V0.

  At time t = t1, the drive control unit 120 starts discharging the battery module 19-1. This discharge is continued until time t = t2 while keeping the battery current value I constant.

  As shown in FIG. 3, immediately after time t = t1 (that is, immediately after the start of discharge), a voltage drop occurs in the internal resistance component of the battery module 19-1, so that the charging voltage value instantaneously decreases by ΔV1.

  After the charging voltage value has decreased by ΔV1, the charging voltage value continues to decrease linearly by constant current discharge by the battery current value I, and decreases by ΔV2 by time t = t2.

  Here, the internal resistance value R and the capacitance value C of the battery module 19-1 can be expressed by the following formulas (1) and (2).

R = ΔV1 / I (1)
C = ∫Idt / ΔV2 (2)
The degree of progress of deterioration of the power storage module used in the power storage unit depends on the temperature of the power storage module and the charging voltage. The higher the temperature and the higher the charging voltage, the faster the degree of progress of deterioration. Therefore, in this embodiment, the degree of deterioration is grasped by the change in resistance value of the internal resistance or the change in capacitance, and the degree of deterioration is adjusted by controlling the temperature or charging voltage of the power storage module. To do. FIG. 4A shows a mode in which the internal resistance increases as the degradation of the power storage module progresses, and FIG. 4B shows a mode in which the capacitance decreases as the power storage module degradation progresses.

  As shown by a solid line in FIG. 4A, the internal resistance values of the battery modules 19-1 to 19-n gradually increase from the initial resistance value R0.

  Here, when there is a difference in the degree of deterioration between the battery modules 19-1 and 19-2, when the charge / discharge control according to the first embodiment is not performed, the battery 19- having a large degree of deterioration, as indicated by a dashed line. The internal resistance value of 1 exceeds the lifetime judgment threshold in Tr1 time.

  Thus, if even one battery module exceeding the threshold value Rt for determining the life of the internal resistance value is included, the performance of the battery 19 as a whole may be degraded, and the overall life may be adversely affected.

  Moreover, as shown in FIG.4 (b), the electrostatic capacitance value of the battery modules 19-1 to 19-n falls gradually from the initial value C0.

  Similarly, when the charge / discharge control according to the first embodiment is not performed with respect to the capacitance value, the internal resistance value of the battery 19-1 having a large deterioration degree is determined as a lifetime in Tc1 time, as shown by a one-dot chain line. It falls below the threshold Ct.

  Thus, if even one battery module that falls below the threshold value Ct for determining the lifetime of the capacitance value is included, the performance of the battery 19 as a whole may deteriorate, and the overall life may be adversely affected.

  On the other hand, in the charge / discharge control device of the first embodiment, the drive control unit 120 measures the internal resistance value as one index representing the degree of deterioration of the battery modules 19-1 to 19-n, and the battery module When the difference ΔR between the internal resistance values 19-1 and 19-2 becomes larger than the predetermined threshold value R1 (t = tr0), the upper limit value of the charging voltage of the battery module 19-1 is reduced.

  Here, when the upper limit value of the charging voltage of the battery module 19-1 is lowered to a predetermined value, the upper limit voltage of the battery module 19-1 is sufficiently slower than the deterioration progress of the module 19-2. The voltage is lowered to a voltage so that the degree of deterioration of the battery module 19-2 catches up with the degree of deterioration of the battery module 19-1.

  Similarly, in the charge / discharge control apparatus according to the first embodiment, the drive control unit 120 uses the capacitance value as one index representing the degree of deterioration of the battery modules 19-1 to 19-n. When the difference ΔC between the capacitance values of the battery modules 19-1 and 19-2 is larger than a predetermined threshold C1 (t = tc0), the upper limit value of the charging voltage of the battery module 19-1 is reduced. Let

  As described above, since the degree of deterioration depends on the temperature and the charging voltage of the battery 19, the degree of charging of the battery module 19-1 having a high degree of deterioration is made lower than the degree of charging of the other battery modules 19-2 to 19-n. As a result, the rate of increase in the internal resistance value of the battery module 19-1 that has deteriorated can be moderated over time as shown by the broken line in FIG. Similarly to 19-2, the life determined based on the internal resistance value can be extended to Tr2 time.

  Similarly, regarding the decrease in the capacitance value, the deterioration of the battery module 19-1 having a high degree of deterioration is further reduced by lowering the charge degree of the other battery modules 19-2 to 19-n. The rate of decrease in the capacitance value of the battery module 19-1 can be made gradually with the passage of time as shown by the broken line in FIG. 4A. For example, the same as the battery module 19-2 In addition, the life determined based on the capacitance value can be extended to Tc2 hours.

  Such adjustment of the degree of charge is performed for each of the battery modules 19-1 to 19-n.

  As described above, according to the charge / discharge control device of the first embodiment, when the deterioration degree varies, the life of the battery module having a high degree of deterioration is reduced by reducing the charge degree of the battery module having a high degree of deterioration. Can be extended.

  Moreover, the lifetime of the whole battery 19 can be extended by reducing the charge degree of a battery module with a high deterioration degree in this way.

  FIG. 5 is a diagram illustrating a processing procedure of a charge degree change process by the charge / discharge control device of the first embodiment. This is a process executed by the drive control unit 120.

  When the operation of the electric drive unit 112 is started, the drive control unit 120 measures the internal resistance value and the capacitance value of the battery modules 19-1 to 19-n (step S11).

  The internal resistance value and the electrostatic capacitance value are discharged by passing the constant current I through the battery modules 19-1 to 19-n and detected by each of the module voltage detection units 130-1 to 130-n. Based on the value and the battery current I (constant current I) detected by the battery current detection unit 107, measurement is performed using the above-described equations (1) and (2).

  The drive control unit 120 determines whether or not there is a variation in the degree of deterioration based on the internal resistance value and the capacitance value of each of the battery modules 19-1 to 19-n (step S12).

  This determination is made based on whether or not the difference ΔR between the lowest internal resistance value and the internal resistance value of another battery module is larger than the above-described threshold value R1.

  Similarly, the capacitance value is determined based on whether or not the difference ΔC between the largest capacitance value and the capacitance value of another battery module is larger than the threshold value C1.

  In the first embodiment, when any one of the internal resistance value and the capacitance value exceeds the threshold value, it is determined that the degree of deterioration has varied.

  If the drive control unit 120 determines that there is variation, the drive control unit 120 reduces the upper limit value of the charging voltage of the battery module having a high degree of deterioration and progressing deterioration (step S13A). Thereby, the lifetime of the battery module in which deterioration has progressed can be extended.

  Here, in the first embodiment, when both the internal resistance value and the capacitance value are measured, it can be determined that there is a variation in deterioration when both exceed the threshold value.

  Furthermore, when either threshold is exceeded, it may be determined that there is variation. In this case, since the battery module with the fastest progress of deterioration can be identified and the progress of deterioration can be suppressed, leveling can be dealt with more quickly.

  Further, since the battery modules 19-1 to 19-n are connected in series, the lowering of the upper limit value of the charging voltage of the battery module 19-1 to 19-n whose deterioration progresses quickly is being charged. In addition, the drive control unit 120 switches the switch (any one of 19D-1 to 19D-n) of the corresponding module to the bypass circuit (any one of 19C-1 to 19C-n), thereby charging the battery module. The voltage can be made to reach the upper limit value after being lowered.

  If it is determined in step S12 that there is no variation, the drive control unit 120 sets the upper limit value of the current charging voltage as the upper limit value of the charging voltage (step S13B). That is, the upper limit value of the charging voltage is not changed.

  The drive control unit 120 performs charge / discharge control of the battery 19 using the upper limit value of the charging voltage changed in step S13A or the upper limit value of the charging voltage not changed in step 3B (step S14).

  When step S14 ends, the drive control unit 120 ends the processing procedure illustrated in FIG.

  In addition, although the form which determines the deterioration degree of the battery modules 19-1 to 19-n every time the operation of the electric drive unit 112 is started has been described above, for example, a predetermined period such as once a week. You may do this once every other time.

  As described above, according to the charge / discharge control device of the first embodiment, when the deterioration degree varies, the charge degree of the battery module having a high deterioration degree is reduced by reducing the charge degree of the battery module having a high deterioration degree. Life can be extended.

  Moreover, the lifetime of the whole battery 19 can be extended by reducing the charge degree of a battery module with a high deterioration degree in this way.

  As mentioned above, about the form implement | achieved by the fall of the upper limit of the charging voltage of the battery modules 19-1 to 19-n by switching the changeover switches 19D-1 to 19D-n to the bypass circuits 19C-1 to 19C-n. As described above, by increasing the rotational speed of the electric fans 19A-1 to 19A-n and increasing the power consumption of the electric fans 19A-1 to 19A-n, the charging voltage of the battery module is predetermined during charging. It is possible to reach the value (upper limit value after reduction).

  In this case, the bypass circuits 19C-1 to 19C-n and the changeover switches 19D-1 to 19D-n are unnecessary.

  In the above description, the form in which both the internal resistance value and the capacitance value of each of the battery modules 19-1 to 19-n are measured to determine the degree of deterioration has been described. One of them may be measured, and the degree of deterioration may be determined based on the measurement result.

  Moreover, although the above demonstrated the form which adjusts each charge degree of the battery modules 19-1 to 19-n based on the deterioration degree of the battery modules 19-1 to 19-n, instead of this, In addition to this, the degree of charge of each battery cell may be adjusted based on the degree of deterioration of the plurality of battery cells included in each of the battery modules 19-1 to 19-n.

  Moreover, although the electric fan 19A-1 to 19A-n was attached to the battery module 19-1 to 19-n as a cooling device above, it demonstrated instead of electric fan 19A-1 to 19A-n. A water-cooled pump or a Peltier element may be used.

[Embodiment 2]
FIG. 6 is a diagram illustrating a configuration of a buck-boost converter and a battery that perform charge / discharge control in the charge / discharge control device of the second embodiment.

  In the charge / discharge control apparatus according to the second embodiment, battery modules 19-1 to 19-n are connected in parallel to each other, and module voltage detection units 130-1 to 130-1 are connected to the battery modules 19-1 to 19-n, respectively. In addition to 130-n, module current detection units 140-1 to 140-n and step-up / down converters 100-1 to 100n are connected.

  That is, the step-up / step-down converters 100-1 to 100n are connected to the DC bus 110 in parallel with each other.

  Each configuration of buck-boost converters 100-1 to 100n is similar to that of buck-boost converter 100 included in the power control circuit of the first embodiment shown in FIG. 1, and includes reactor 101, step-up IGBT 102A, step-down IGBT 102B, A power connection terminal 103, an output terminal 104, and a capacitor 105 are included.

  The buck-boost converter 100 according to the first embodiment includes a battery voltage detection unit 106 and a battery current detection unit 107. However, the buck-boost converters 100-1 to 100n according to the second embodiment include the battery voltage detection unit 106 and the battery. Instead of including the current detection unit 107, the module voltage detection units 130-1 to 130-n and the module current detection units 140-1 to 140-n are connected, and the module voltage detection units 130-1 to 130-1 are connected. The step-up / step-down operation is performed based on the voltage value and the current value detected by 130-n and the module current detection units 140-1 to 140-n.

  FIG. 7 is a diagram illustrating a processing procedure of a charge degree changing process by the charge / discharge control device of the second embodiment. This is a process executed by the drive control unit 120. However, in the case of parallel connection, since the battery modules 19-1 to 19-n have a constant charging voltage value, the lifetime cannot be extended by changing the upper limit value of the charging voltage as in the first embodiment. Here, in the second embodiment, attention is paid to the fact that the life of the battery 19 is affected by the temperature. By limiting the charging current to the battery modules 19-1 to 19-n, heat generation is suppressed, and the degree of progress of deterioration is reduced. A mode in which the progress of deterioration of the battery modules 19-1 to 19-n can be leveled by lowering the temperature of the battery module having a high value will be described.

  When the operation of the electric drive unit 112 is started, the drive control unit 120 uses the above-described equations (1) and (2) to determine the internal resistance values and capacitances of the battery modules 19-1 to 19-n. A value is measured (step S21).

  The internal resistance value and the capacitance value are detected by each of the module voltage detection units 130-1 to 130-n by causing each of the battery modules 19-1 to 19-n to discharge the constant current I. Based on the charging voltage value and the battery current I (constant current I) detected by each of the module current detection units 140-1 to 140-n, measurement is performed using the above-described formulas (1) and (2). Is done.

  The drive control unit 120 determines whether or not there is a variation in the degree of deterioration based on the internal resistance value and the capacitance value of each of the battery modules 19-1 to 19-n (step S22).

  This determination is made based on whether or not the difference ΔR between the lowest internal resistance value and the internal resistance value of another battery module is larger than the above-described threshold value R1.

  Similarly, the capacitance value is determined based on whether or not the difference ΔC between the largest capacitance value and the capacitance value of another battery module is larger than the threshold value C1.

  In the second embodiment, when any one of the internal resistance value and the capacitance value exceeds the threshold value, it is determined that the degree of deterioration has varied.

  If the drive control unit 120 determines that there is variation, the drive control unit 120 reduces the upper limit value of the charging current of the battery module having a high degree of deterioration and progressing deterioration to a predetermined current value (step S23A). Thereby, since the heat generation by the internal resistance can be suppressed, the life of the battery module whose deterioration has progressed can be extended.

  Here, the battery modules 19-1 to 19-n are connected in parallel, and step-up / down converters 100-1 to 100 n are disposed between the battery modules 19-1 to 19-n and the DC bus 110.

  For this reason, to reduce the upper limit value of the charging current of any of the battery modules 19-1 to 19-n, the drive control unit 120 causes the buck-boost converters 100-1 to 100n to perform a step-down operation. It is realized by lowering the upper limit value when charging each of −1 to 19-n.

  When it is determined in step S22 that there is no variation, the drive control unit 120 sets the current upper limit value of the charging current as the upper limit value of the charging current (step S23B). That is, the upper limit value of the charging current is not changed.

  The drive control unit 120 performs charge / discharge control of the battery 19 using the upper limit value of the charging current changed in step S23A or the upper limit value of the charging current not changed in step 3B (step S24).

  When step S24 ends, the drive control unit 120 ends the processing procedure shown in FIG.

  As described above, according to the charge / discharge control device of the second embodiment, when the deterioration degree of the battery modules 19-1 to 19-n varies, the charge degree of the battery module having a high deterioration degree is reduced. As a result, the life of the battery module having a high degree of deterioration can be extended.

  Moreover, the lifetime of the whole battery 19 can be extended by reducing the charge degree of a battery module with a high deterioration degree in this way.

  In the above description, the form in which both the internal resistance value and the capacitance value of each of the battery modules 19-1 to 19-n are measured to determine the degree of deterioration has been described. The degree of deterioration may be determined based on one of them.

[Embodiment 3]
FIG. 8 is a diagram illustrating a processing procedure of a charge degree changing process by the charge / discharge control device of the third embodiment. This is a process executed by the drive control unit 120.

  The charging / discharging control device of the third embodiment is different from the first and second embodiments in that the degree of cooling of each of the battery modules 19-1 to 19-n is adjusted instead of adjusting the degree of charging.

  The battery modules 19-1 to 19-n may be connected in series or in parallel, and the circuit configuration may be any of the configurations shown in FIG. 2 or FIG. The bypass circuits 19C-1 to 19C-n and the changeover switches 19D-1 to 19D-n are unnecessary.

  When the operation of the electric drive unit 112 is started, the drive control unit 120 uses the above-described equations (1) and (2) to determine the internal resistance values and capacitances of the battery modules 19-1 to 19-n. The value is measured (step S31).

  Here, when the battery modules 19-1 to 19-n are connected in series, the internal resistance value and the capacitance value are measured in the same manner as in step S11 in the first embodiment. 1 to 19-n are caused to flow by discharging a constant current I, the charging voltage value detected by each of the module voltage detection units 130-1 to 130-n, and the battery current detected by the battery current detection unit 107 Based on I (constant current I), measurement is performed using the above-described equations (1) and (2).

  Further, when the battery modules 19-1 to 19-n are connected in parallel, the constant current I is passed through each of the battery modules 19-1 to 19-n as in step S21 in the second embodiment. The charging voltage value detected by each of the module voltage detection units 130-1 to 130-n and the battery current I (fixed) detected by each of the module current detection units 140-1 to 140-n. Based on the current I), measurement is performed using the above-described equations (1) and (2).

  The drive control unit 120 determines whether there is a variation in the degree of deterioration based on the internal resistance value and the capacitance value of each of the battery modules 19-1 to 19-n (step S32).

  This determination is made based on whether or not the difference ΔR between the lowest internal resistance value and the internal resistance value of another battery module is larger than the above-described threshold value R1.

  Similarly, the capacitance value is determined based on whether or not the difference ΔC between the largest capacitance value and the capacitance value of another battery module is larger than the threshold value C1.

  In the third embodiment, when any one of the internal resistance value and the electrostatic capacitance value exceeds the threshold value, it is determined that the degree of deterioration varies.

  If the drive control unit 120 determines that there is a variation, the drive control unit 120 increases the rotation speed of the electric fan of the battery module having a high degree of deterioration and progressing deterioration to a predetermined rotation speed (step S33A). Thereby, the battery module in which the deterioration has progressed is cooled more than the other battery modules, and the life can be extended.

  If it is determined in step S32 that there is no variation, the drive control unit 120 sets the upper limit value of the current charging voltage as the upper limit value of the charging voltage (step S33B). That is, the upper limit value of the charging voltage is not changed.

  The drive control unit 120 performs charge / discharge control of the battery 19 using the upper limit value of the charging voltage changed in step S33A or the upper limit value of the charging voltage not changed in step 3B (step S34).

  When step S34 ends, the drive control unit 120 ends the processing procedure illustrated in FIG.

  As described above, according to the charge / discharge control device of the third embodiment, when the degree of deterioration varies, the degree of cooling of the battery module having a high degree of deterioration is increased by increasing the degree of cooling of the battery module having a high degree of deterioration. Life can be extended.

  Moreover, the lifetime of the battery 19 as a whole can be extended by increasing the degree of cooling of the battery module having a high degree of deterioration.

  Moreover, although it showed about the form implement | achieved by increasing the rotation speed of each electric fan of the battery modules 19-1 to 19-n to the predetermined rotation speed, instead of changing the rotation speed of the electric fan, This can also be realized by lowering the temperature setting value at the start of rotation of the electric fan. In this case, the electric fan provided in the battery module having a high degree of deterioration is caused to start rotating earlier than the electric fans of the other battery modules. The life of the battery module having a high degree of deterioration can be extended.

  In the above description, the form in which both the internal resistance value and the capacitance value of each of the battery modules 19-1 to 19-n are measured to determine the degree of deterioration has been described. The degree of deterioration may be determined based on one of them.

  The charge / discharge control apparatus according to the exemplary embodiment of the present invention has been described above, but the present invention is not limited to the specifically disclosed embodiment, and departs from the scope of the claims. Various modifications and changes are possible.

DESCRIPTION OF SYMBOLS 19 Battery 19-1 to 19-n Battery module 19A-1 to 19A-n Electric fan 19B-1 to 19B-n Battery part 19C-1 to 19C-n Bypass circuit 19D-1 to 19D-n Changeover switch 100, 100 -1 to 100n Buck-Boost Converter 101 Reactor 102A Boost IGBT
102B IGBT for step-down
DESCRIPTION OF SYMBOLS 103 Power supply terminal 104 Output terminal 105 Capacitor 106 Battery voltage detection part 107 Battery current detection part 110 DC bus 111 DC bus voltage detection part 112 Electric drive part 120 Drive control part 130-1 to 130-n Module voltage detection part 140-1 ~ 140-n Module current detector

Claims (4)

A charge / discharge control device that performs charge / discharge control of a plurality of power storage units that exchange electric power with an electric drive unit that is electrically driven,
A deterioration degree detection unit for detecting the deterioration degree of each of the plurality of power storage units;
An adjustment unit that adjusts at least one of the plurality of power storage units based on the detection result of the deterioration level detection unit,
The said adjustment part is a charging / discharging control apparatus which adjusts the said charge degree based on the internal resistance value or electrostatic capacitance value of these electrical storage parts.   2. The adjustment unit according to claim 1, wherein when there is a variation in the deterioration levels of the plurality of power storage units detected by the deterioration level detection unit, the adjustment unit decreases a charge level of the power storage unit having a high deterioration level. Charge / discharge control device.   The adjusting unit adjusts the degree of charge by adjusting an upper limit value of a charging voltage of at least one of the power storage units when each of the plurality of power storage units is connected in series. Item 3. The charge / discharge control device according to Item 1 or 2.   The adjustment unit adjusts the degree of charge by adjusting a charge / discharge current value of at least one of the power storage units when each of the plurality of power storage units is connected in parallel to each other. The charge / discharge control apparatus according to 1 or 2.

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