JP6206117B2 - Battery module control device and battery module state determination method - Google Patents

Description

  The present invention relates to a battery module control device including a plurality of secondary batteries and a battery module state determination method.

  In a non-aqueous secondary battery module in which a plurality of unit cells are connected, the voltage of each unit cell is monitored, and the minimum and maximum voltage of the unit cell when the non-aqueous secondary battery module discharge depth is 80% or more. A control method is known in which, when the difference is greater than or equal to a set value, a predetermined control is performed and the voltage variation of the unit cells is leveled (see, for example, Patent Document 1).

JP 2003-282151 A

  In the above technique, it is impossible to determine the cause of the voltage difference between the minimum voltage and the maximum voltage of the unit cell being greater than or equal to the set value. For this reason, there existed a problem that control according to the kind of malfunction which a nonaqueous system rechargeable battery module had might not be performed.

  The problem to be solved by the present invention is to provide a battery module control device and a battery module state determination method capable of performing control in accordance with the type of failure of the battery module.

  The present invention classifies a terminal voltage difference, which is a difference between a maximum value and a minimum value in the terminal voltage of each secondary battery, according to a predetermined condition in a plurality of electrically connected secondary batteries, and the classification result The above-mentioned problem is solved by determining the temporal change pattern of the terminal voltage difference based on the above.

  According to the present invention, it is possible to estimate the type of defect that the battery module has based on the determination result of the temporal change pattern in the terminal voltage difference. Thereby, it becomes possible to control the battery module in accordance with the type of defect that the battery module has.

FIG. 1 is a conceptual diagram of a vehicle equipped with a control system having a control device according to an embodiment of the present invention. FIG. 2 is a block diagram showing a control system having a control device according to the embodiment of the present invention. FIG. 3A is a flowchart (part 1) illustrating control by the control device according to the embodiment of the present invention. FIG. 3B is a flowchart (part 2) illustrating the control by the control device according to the embodiment of the present invention. FIG. 4A and FIG. 4B are graphs for explaining the first and second deviation patterns in the embodiment of the present invention, and FIG. 4A is a diagram for explaining the first deviation pattern. FIG. 4B is a graph for explaining the second divergence pattern. FIG. 5 is a graph for explaining a linear increase pattern in the embodiment of the present invention. FIG. 6 is a graph for explaining a curve increasing pattern in the embodiment of the present invention. FIG. 7 is a graph showing the relationship between the SOC and the terminal voltage in the secondary battery.

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

  FIG. 1 is a conceptual diagram of a vehicle equipped with a control system having a control device according to this embodiment, and FIG. 2 is a block diagram showing the control system having a control device according to this embodiment.

  As shown in FIGS. 1 and 2, the control system 11 having the control device 4 in this embodiment includes a battery module 2, a power unit 3, and a notification device 5 in addition to the control device 4. . In the present embodiment, the control system 11 is mounted on a vehicle 1 such as an electric vehicle. In addition, you may use the said control system 11 for a household electrical storage apparatus.

  As shown in FIG. 2, the battery module 2 is configured by connecting a plurality (n) of secondary batteries 21 composed of lithium ion secondary batteries or the like electrically in series.

  The power unit 3 is composed of an electric motor or the like, and drives the vehicle 1 by consuming electric power of the battery module 2 converted into alternating current by an inverter (not shown).

  As shown in FIG. 2, the control device 4 in the present embodiment includes a terminal voltage measurement unit 41, a first calculation unit 42, a threshold determination unit 421, a classification unit 43, a timer 441, a storage unit 442, A pattern determination unit 45, a second calculation unit 46, and a control unit 47 are provided.

The terminal voltage measurement unit 41 includes a voltmeter or the like, and each time the vehicle 2 is prepared for start-up, each terminal voltage (V ₁ , V ₂ ) in the n secondary batteries 21 constituting the battery module _2. ,..., V _n ) are repeatedly measured. The value of the terminal voltage of each secondary battery 21 measured by the terminal voltage measurement unit 41 is sent to the first calculation unit 42. The terminal voltage measuring unit 41 in the present embodiment corresponds to an example of a terminal voltage measuring unit of the present invention.

The first calculation unit 42 configures the battery module 2 every time the terminal voltage measurement unit 41 measures the terminal voltages (V ₁ , V ₂ ,..., V _n ) of the _n secondary batteries 21. An average value V _ave (= (V ₁ + V ₂ ,... + V _n ) / n) of terminal voltages of the n secondary batteries 21 is calculated. Further, the first calculation unit 42 calculates a difference (V _max −V _min ) between the maximum value V _max and the minimum value V _min from the n terminal voltages. In the following description, this difference (V _max −V _min ) is also referred to as a terminal voltage difference ΔV. The 1st calculating part 42 in this embodiment is equivalent to an example of the 1st calculating means of this invention.

  As the first calculation unit 42 and the threshold value determination unit 421, the classification unit 43, the timer 441, the storage unit 442, the pattern determination unit 45, the second calculation unit 46, and the control unit 47 described below, for example, A CPU, ROM, RAM, and the like can be mainly configured.

The threshold determination unit 421 determines whether or not the terminal voltage difference ΔV calculated by the first calculation unit 42 exceeds a predetermined threshold set in advance. In response to the determination result, the first calculation unit 42 determines that the terminal voltage difference ΔV and the terminal voltage (V ₁ , V ₂ ,...) When the terminal voltage difference ΔV exceeds the threshold. The average value V _ave of V _n ) is sent to the classification unit 43.

The classification unit 43 classifies the terminal voltage difference ΔV calculated by the first calculation unit 42. Specifically, a group of terminal voltage differences ΔV in which the average value V _ave of terminal voltages belongs to a predetermined first voltage range (V1 _low ≦ V _ave ≦ V1 _high ) (hereinafter, also referred to as a first terminal voltage difference group). And a group of terminal voltage differences ΔV in which the average value V _ave of the terminal voltages belongs to a predetermined second voltage range (V2 _low ≦ V _ave ≦ V2 _high ) (hereinafter also referred to as a second terminal voltage difference group). Terminal voltage difference ΔV. In this case, the second voltage range (V2 _low ≤ V _ave ≤ V2 _high ) is set relatively lower than the first voltage range (V1 _low ≤ V _ave ≤ V1 _high ) (V2 _high < V1 _low ). The classified terminal voltage difference ΔV is sent to the storage unit 442. The classification unit 43 in the present embodiment corresponds to an example of a classification unit of the present invention.

  The timer 441 has a function of measuring an elapsed time after the control device 4 starts control.

  The storage unit 442 stores the terminal voltage difference ΔV classified by the classification unit 43 based on the measurement result of the timer 441 in time series. Further, the stored terminal voltage difference ΔV is sent to the pattern determination unit 45.

  The pattern determination unit 45 determines a temporal change pattern of the terminal voltage difference ΔV based on the classification result of the terminal voltage difference ΔV stored in the storage unit 442. Further, the pattern determination unit 45 further determines a temporal change pattern of the terminal voltage difference ΔV according to the calculation result by the second calculation unit 46. The determination result by the pattern determination unit 45 is sent to the control unit 47. The pattern determination unit 45 in the present embodiment corresponds to an example of a pattern determination unit of the present invention.

  The second calculation unit 46 calculates a correlation coefficient (linear correlation coefficient) when linearly approximating the relationship between the first terminal voltage difference group and the elapsed time, and also calculates the first terminal voltage difference group and The correlation coefficient (curve correlation coefficient) when the curve is approximated with respect to the relationship of the elapsed time is calculated. The correlation coefficient (linear correlation coefficient and curve correlation coefficient) may be calculated for the relationship between the second terminal voltage difference group and the elapsed time, and the first terminal voltage difference group and the second terminal voltage difference group may be calculated. It is good also as calculating the correlation coefficient (a linear correlation coefficient and a curve correlation coefficient) about the relationship between both data of a terminal voltage difference group, and elapsed time.

  The control unit 47 performs preset control based on the temporal change pattern of the terminal voltage difference ΔV determined by the pattern determination unit 45. Further, the control unit 47 sends a command to the notification device 5 so as to notify the driver of the vehicle 1 based on the determination result.

  The notification device 5 receives a command from the control unit 47 and notifies the driver of the vehicle 1 by an image, sound, a warning lamp, or the like.

  Next, control performed by the control device 4 in the present embodiment will be described. 3A and 3B are flowcharts showing the control by the control device 4, and FIGS. 4A, 4B, 5, and 6 are graphs for explaining the temporal change pattern of the terminal voltage difference ΔV. It is. In this example, a case where a lithium ion secondary battery is used as the secondary battery 21 and 100 secondary batteries 21 are connected in series (n = 100) to configure the battery module 2 will be described.

  First, when the start switch of the vehicle 1 is turned on as step S01, the presence / absence of the travel prohibition control for the vehicle 1 is determined as step S02. The travel prohibition control is control that prevents the vehicle 1 from being activated, and is control that is executed when the vehicle 1 has some trouble or the like. When the travel prohibition control is being performed, the control by the control unit 4 is terminated. If the travel prohibition control is not performed, the process proceeds to step S03.

In step S03, the vehicle 1 is activated, and the terminal voltage measurement unit 41 of the control device 4 uses the terminal voltages (V ₁ , V ₂ ,..., V _n ) of the secondary batteries 21 constituting the battery module 2. Measure (corresponds to an example of the first step of the present invention).

  Next, in step S04, based on the terminal voltage of the secondary battery 21 measured by the terminal voltage measurement unit 41, the first calculation unit 42 measures the terminal voltage difference ΔV (corresponding to an example of the second step of the present invention). To do.) When the threshold determination unit 421 determines that the terminal voltage ΔV is equal to or higher than a predetermined threshold (100 mV in this example), the process proceeds to step S05. Thus, by performing the following control when the terminal voltage difference ΔV is greater than or equal to a predetermined threshold value, erroneous determination at the time of determining the temporal change pattern in the terminal voltage difference ΔV is suppressed. When the threshold determination unit 421 determines that the terminal voltage difference ΔV is less than the threshold, the start switch is turned off (step S13), and the control ends.

In step S05, first, the first calculation unit 42 calculates an average value V _ave of the terminal voltages (V ₁ , V ₂ ,..., V _n ) of the secondary battery 21. Then, the classification unit 43 classifies the terminal voltage difference ΔV according to a predetermined condition. That is, when the average value V _ave belongs to a predetermined first voltage range (V1 _low ≦ V _ave ≦ V1 _high ), the classification unit 43 classifies the terminal voltage difference ΔV into the first terminal voltage difference group. . On the other hand, when the average value V _ave belongs to a predetermined second voltage range (V2 _low ≦ V _ave ≦ V2 _high ), the classification unit 43 classifies the terminal voltage difference ΔV into the second terminal voltage difference group ( This corresponds to an example of the third step of the present invention). And the memory | storage part 442 memorize | stores said classification | category result performed along the time series.

Next, based on the classification result and the past classification result of the terminal voltage difference ΔV stored in the storage unit 442, the pattern determination unit 45 determines the maximum value ΔV1 _max of the terminal voltage difference ΔV in the first terminal voltage difference group. And an absolute value D (= ΔV2 _max −ΔV1 _max, hereinafter also referred to as a voltage state difference D) between the maximum value ΔV2 _max of the terminal voltage difference ΔV in the second terminal voltage difference group, and step S06. Proceed to

In the above-described classification in step S05, the first and second are expressed as V2 _high <(voltage less than 50% SOC in the secondary battery 21) and V1 _low ≧ (voltage more than 50% SOC in the secondary battery 21). The voltage range may be set. Alternatively, the first and second voltage ranges may be set so as to satisfy V2 _high <3900 mV and V1 _low ≧ 3900 mV. In these cases, the difference in tendency between the first terminal voltage difference group and the second terminal voltage difference group becomes significant, and the temporal change pattern of the terminal voltage difference ΔV can be determined more accurately.

Further, in the storage of the classification result in step S05, when the average value V _ave is higher than 3900 mV (V _ave > 3900 mV), normalization is performed by multiplying the terminal voltage difference ΔV by the coefficient h ₁ (h ₁ > 1). When the average value V _ave is 3900 mV (V _ave = 3900 mV), the terminal voltage difference ΔV is normalized by a coefficient h ₂ (h ₂ = 1), and when the average value V _ave is lower than 3900 mV (V _ave <3900 mV), the terminal voltage difference normalized by multiplying the terminal voltage difference ΔV by the coefficient h ₃ (h ₃ <1) may be stored in the storage unit 442. Also in this case, the difference in tendency between the first terminal voltage difference group and the second terminal voltage difference group becomes significant, and the accuracy in determining the temporal change pattern of the terminal voltage difference ΔV can be improved.

Further, instead of the average value V _ave in step S05, the maximum value V _max of the terminal voltages (V ₁ , V ₂ ,..., V _n ) of all the secondary batteries 21 included in the battery module 2 is used. The above classification may be performed. In this case, the calculation of the average value V _ave can be omitted, so that the calculation load on the first calculation unit 42 can be reduced.

Returning to the flowchart (FIG. 3B), in step S06, the voltage state difference D is 100 mV (corresponding to an example of the first predetermined value of the present invention) or more (D ≧ 100 mV), and the first terminal. When the maximum value ΔV1 _max of the terminal voltage difference ΔV in the voltage difference group is less than a predetermined value (100 mV in this example) (ΔV1 _max <100 mV) (Yes in step S06), the process proceeds to step S07.

  In step S07, the pattern determination unit 45 determines that the temporal change pattern of the terminal voltage difference ΔV over a certain period (d days) is a divergence pattern (first terminal voltage difference group (graph (graph)) shown in the graph of FIG. a) and a second terminal voltage difference group (graph b), a temporal change pattern that spreads over time (corresponding to an example of the first deviation pattern of the present invention). This corresponds to an example of the fourth step of the invention). The fixed period (d days) for determining the temporal change pattern of the terminal voltage difference ΔV is preferably 5 days or more from the viewpoint of improving the accuracy of the determination, and more preferably 30 days or more. preferable.

  In response to the determination result, the control unit 47 indicates that the capacity balance between the electrodes has deteriorated in some of the secondary batteries 21 of the plurality of secondary batteries 21 constituting the battery module 2. A command is issued to the notification device 5 to notify the driver. Next, when the start switch is turned off (step S13), the control ends.

In this case, as shown in FIG. 4 (B), the pattern determination unit 45 performs the first terminal voltage difference group (graph a in the figure. Third terminal of the present invention) for a certain period (d days). This corresponds to an example of a voltage difference group.) And the slope G ₁ of the first regression line indicating the correlation between the elapsed time and the second terminal voltage difference group (graph b in the figure. Fourth of the present invention) This corresponds to an example of a terminal voltage difference group.) And an absolute difference (G ₂ −G ₁ ) between the slope G ₂ of the second regression line indicating the correlation between the elapsed time and the terminal voltage difference ΔV. A temporal change pattern may be determined.

  Specifically, the pattern determination unit 45 has an absolute difference between the slope of the first regression line and the slope of the second regression line equal to or greater than a second predetermined value (for example, 0.3), and When the slope of the regression line of 1 is a predetermined value (for example, 0.2) or less, the temporal change pattern of the terminal voltage difference ΔV is a deviation pattern (corresponding to an example of the second deviation pattern of the present invention). Judge that there is.

  The absolute difference between the slope of the first regression line and the slope of the second regression line is less than a second predetermined value (for example, 0.3), and the slope of the first regression line is a predetermined value. When it is larger than (for example, 0.2), it is determined that the temporal change pattern is a follow-up pattern (described later, which corresponds to an example of the second follow-up pattern of the present invention). In these cases, the temporal change pattern of the terminal voltage difference ΔV can be more accurately determined based on the tendency of the terminal voltage difference ΔV for a certain period (d days).

  Returning to FIG. 3B, in the case of No in step S06, the temporal change pattern of the terminal voltage difference ΔV is a tracking pattern (the first terminal voltage difference group and the second terminal voltage difference group do not deviate with time, The pattern determination unit 45 determines that the temporal change patterns follow each other (corresponding to an example of the first tracking pattern of the present invention), and the process proceeds to step S08.

In step S08, the voltage state difference D is less than 100 mV (D <100 mV), and the maximum value ΔV1 _max of the terminal voltage difference ΔV in the first terminal voltage difference group is greater than or equal to a predetermined value (100 mV in this example) ( If ΔV1 _max ≧ 100 mV) (Yes in step S08), the process proceeds to step S09. If No in step S08, the start switch is turned off (step S13), and the control ends.

In step S09, in the second calculation unit 46, a correlation coefficient R ₁ ² (hereinafter referred to as a linear approximation of the relationship between the first terminal voltage difference group and the elapsed time since the control device 4 started control). , Also referred to as a linear correlation coefficient R ₁ ² ). When the linear correlation coefficient R ₁ ² is 0.6 or more (R ₁ ² ≧ 0.6), the temporal change pattern of the terminal voltage difference ΔV in a certain period (d days) is a linear increase pattern ( A pattern determination unit when the first terminal voltage difference group (graph a in FIG. 5) or the second terminal voltage difference group (graph b in FIG. 5) increases linearly with time. 45 determines and proceeds to step S10.

  In step S10, in response to the determination result of the pattern determination unit 45, a contact failure in a bus bar (not shown) constituting the battery module 2, a tab constituting the secondary battery 21, or an electrode active material layer (none is shown). (Hereinafter, also referred to as mechanical degradation), the control unit 47 issues a command to the notification device 5 so as to notify the driver that a problem has occurred. Further, the control unit 47 performs the travel prohibition control of the vehicle 1 after a certain time has elapsed (for example, after 7 days). Next, when the start switch is turned off (step S13), the control ends.

In step S09, when the linear correlation coefficient R ₁ ² is less than 0.6 (R ₁ ² <0.6), the process proceeds to step S11.

In step S11, in the second calculation unit 46, a correlation coefficient R ₂ ² (hereinafter referred to as a curve approximation) is used to approximate the relationship between the first terminal voltage difference group and the elapsed time since the control device 4 started control. , Also referred to as curve correlation coefficient R ₂ ² ). In this case, the curve to be approximated by a curve may be a quadratic curve or a cubic curve, or may be approximated by a polynomial of an arbitrary order k expressed by the following equation (1).
Y = A * ^Xk + B * X ^(k-1) + ... + Z ... (1)
However, in the above equation (1), X is the elapsed time, Y is the terminal voltage difference ΔV, and A, B, and Z are arbitrary constants.

Curve correlation coefficient _R ^{2 2} is 0.6 or more in the case of _(R ^{2 2} ≧ 0.6), the aging pattern of the terminal voltage difference ΔV over a period of time (between d days) curve increases pattern (first If the terminal voltage difference group (graph a in FIG. 6) or the second terminal voltage difference group (graph b in FIG. 6) increases with time, the pattern determination unit 45 Determine and proceed to step S12.

  In step S12, in response to the determination result of the pattern determination unit 45, in the secondary battery 21, a problem due to deterioration due to irreversible reaction (hereinafter also referred to as chemical deterioration) due to film formation on the electrode surface, decomposition of the electrolytic solution, or the like. The controller 47 issues a command to the notification device 5 so as to notify the driver that the vehicle has occurred, and performs a travel prohibition control of the vehicle 1. Next, when the start switch is turned off (step S13), the control ends.

When the curve correlation coefficient R ₂ ² is less than 0.6 (R ₂ ² <0.6), the control unit 47 does not perform control according to the temporal change pattern of the terminal voltage difference ΔV, and the start switch Is turned off (step S13), the control ends.

  Next, the operation of this embodiment will be described.

  In the control device 4 according to the present embodiment, the first calculation unit 42 calculates the terminal voltage difference ΔV based on the terminal voltage of the secondary battery 21 measured by the terminal voltage measurement unit 41, and the terminal voltage difference ΔV is elapsed over time. The battery module 2 is controlled according to the change pattern. Thereby, the kind of malfunction which the said battery module 2 has can be estimated, and control of each secondary battery 21 can be performed based on the result of the said estimation.

  That is, generally, since the terminal voltage of the secondary battery and the SOC (State of Charge) of the secondary battery are positively correlated, the terminal voltage tends to increase as the SOC increases (graph a in FIG. 7). ). Here, when the terminal voltage decreases on the low SOC side (graph b in FIG. 7), it is estimated that the capacity balance between the electrodes of the secondary battery is degraded. When such deterioration occurs in some of the plurality of secondary batteries, the temporal change pattern of the terminal voltage difference ΔV is a deviation pattern.

  For this reason, when it is determined that the temporal change pattern of the terminal voltage difference ΔV is a divergence pattern, with respect to some of the secondary batteries 21 constituting the battery module 2, Control suitable for the degradation can be performed.

  In addition, when the terminal voltage decreases over the entire SOC range (graph c in FIG. 7), it is estimated that mechanical or chemical deterioration has occurred in the secondary battery. When such deterioration occurs in the whole of the plurality of secondary batteries, the temporal change pattern of the terminal voltage difference ΔV becomes a follow-up pattern. Therefore, when the pattern determination unit 45 of the control device 4 determines that the temporal change pattern of the terminal voltage difference ΔV is a follow-up pattern, the entire plurality of secondary batteries 21 constituting the battery module 2 are determined. Control suitable for the degradation can be performed.

  In this case, when the temporal change pattern of the terminal voltage difference ΔV is a linear increase pattern, it is further estimated that the deterioration occurring in the secondary battery 21 is a mechanical deterioration. For this reason, it becomes possible to perform the control suitable for the said mechanical degradation with respect to the whole secondary battery 21 which the battery module 2 has.

  In addition, when the pattern determination unit 45 determines that the temporal change pattern of the terminal voltage difference ΔV is a curve increase pattern, the deterioration occurring in the secondary battery 21 is further estimated to be chemical deterioration. The For this reason, it becomes possible to perform the control suitable for the said chemical degradation with respect to the whole secondary battery 21 which the battery module 2 has.

  As described above, the control device 4 according to the present embodiment estimates the type of failure that the battery module 2 has based on the temporal change pattern of the terminal voltage difference ΔV, and performs appropriate control according to the type and urgency of the failure. Can be done.

  In the present embodiment, the driver of the vehicle 1 is notified according to the determined temporal change pattern (deviation pattern, linear increase pattern, and curve increase pattern). Accordingly, the driver can recognize the state of the battery module 2 (the presence / absence of the defect, the type of the defect), and if the battery module 2 has a problem, the driver is informed of the type of the problem. Appropriate treatment can be encouraged.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, although not particularly illustrated, by providing a vehicle with a transmission / reception device that transmits / receives data to / from an external data center, the measurement result by the terminal voltage measurement unit is transmitted to the data center. The first and second calculation units, threshold determination unit, classification unit, timer, storage unit, and pattern determination unit may be used.

  In addition, for example, via a transmission / reception device provided in the vehicle, information on the state of the battery module (existence of failure, type, etc.) is transmitted to an external system that manages replacement parts of the vehicle. Based on the received information, inventory management of replacement parts required by the vehicle may be performed.

DESCRIPTION OF SYMBOLS 1 ... Vehicle 2 ... Battery module 21 ... Secondary battery 4 ... Control apparatus 41 ... Terminal voltage measurement part 42 ... 1st calculating part 43 ... Classification part 45 ... Pattern determination unit 46 ... second calculation unit 47 ... control unit 5 ... notification device

Claims (4)

A battery module control device for controlling a battery module having a plurality of secondary batteries electrically connected in series,
Terminal voltage measuring means for repeatedly measuring terminal voltages of the plurality of secondary batteries;
Each time the terminal voltage measuring means measures once, a terminal voltage difference that is a difference between the maximum value of the terminal voltages of the plurality of secondary batteries and the minimum value of the terminal voltages of the plurality of secondary batteries is calculated. First computing means to
Classification means for classifying the terminal voltage difference into a first terminal voltage difference group and a second terminal voltage difference group ;
Pattern determination means for determining a temporal change pattern of the terminal voltage difference based on a classification result by the classification means ,
The first terminal voltage difference group is a group of terminal voltage differences in which an average value of terminal voltages of the plurality of secondary batteries belongs to a predetermined first voltage range,
The second terminal voltage difference group is a group of terminal voltage differences belonging to a predetermined second voltage range in which the average value is relatively lower than the first voltage range,
The pattern determination means determines that the temporal change pattern is a first divergence pattern when the voltage state difference is equal to or greater than a first predetermined value,
The pattern determination means determines that the temporal change pattern is a first follow-up pattern when the difference between the voltage states is less than the first predetermined value;
The difference between the voltage states is an absolute difference between the terminal voltage difference that is the maximum value of the first terminal voltage difference group and the terminal voltage difference that is the maximum value of the second terminal voltage difference group. ,
The first divergence pattern is the time-varying pattern such that a space between the first terminal voltage difference group and the second terminal voltage difference group spreads over time.
The battery module characterized in that the first follow-up pattern is the time-varying pattern in which the first terminal voltage difference group and the second terminal voltage difference group follow each other over time. Control device. A battery module control device for controlling a battery module having a plurality of secondary batteries electrically connected in series,
Terminal voltage measuring means for repeatedly measuring terminal voltages of the plurality of secondary batteries;
Each time the terminal voltage measuring means measures once, a terminal voltage difference that is a difference between the maximum value of the terminal voltages of the plurality of secondary batteries and the minimum value of the terminal voltages of the plurality of secondary batteries is calculated. First computing means to
Classification means for classifying the terminal voltage difference into a third terminal voltage difference group and a fourth terminal voltage difference group ;
Pattern determination means for determining a temporal change pattern of the terminal voltage difference based on a classification result by the classification means ,
The third terminal voltage difference group is a group of terminal voltage differences in which an average value of terminal voltages of the plurality of secondary batteries belongs to a predetermined third voltage range.
The fourth terminal voltage difference group is a group of the terminal voltage differences belonging to a predetermined fourth voltage range in which the average value is relatively lower than the third voltage range,
The pattern determination means determines that the temporal change pattern is a second deviation pattern when the slope difference is equal to or greater than a second predetermined value,
The pattern determination means determines that the temporal change pattern is a second follow-up pattern when the slope difference is less than the second predetermined value,
The slope difference is an absolute difference between the slope of the first regression line and the slope of the second regression line,
The second divergence pattern is the time-varying pattern such that a space between the third terminal voltage difference group and the fourth terminal voltage difference group spreads over time.
The second tracking pattern is the time-varying pattern such that the third terminal voltage difference group and the fourth terminal voltage difference group follow each other over time,
The first regression line is a regression line indicating the relationship between the third terminal voltage difference group and the elapsed time;
The battery module control device, wherein the second regression line is a regression line indicating a relationship between the fourth terminal voltage difference group and an elapsed time . The battery module control device according to claim 1 ,
A second that calculates a linear correlation coefficient when the relationship between the first terminal voltage difference group or the second terminal voltage difference group and the elapsed time is linearly approximated, and a curve correlation coefficient when the curve is approximated It is equipped with the calculation means
It said second computing means, the temporal change pattern when it is determined that the first following pattern is the pattern determining unit calculates the linear correlation coefficient,
When the linear correlation coefficient is 0.6 or more, the pattern determination means indicates that the time-varying pattern is such that the first terminal voltage difference group or the second terminal voltage difference group is linear with time. Judge that it is a linear increase pattern that increases,
The second calculation means further calculates the curve correlation coefficient when the linear correlation coefficient is less than 0.6,
When the curve correlation coefficient is 0.6 or more, the pattern determination means indicates that the temporal change pattern is a curve of the first terminal voltage difference group or the second terminal voltage difference group over time. A control device for a battery module, characterized in that it is determined to be an increasing curve pattern. The battery module control device according to claim 2 ,
Before Symbol third terminal voltage difference Gunmata calculates the curve correlation coefficient when the linear correlation coefficients and curve fitting upon linear approximation and the fourth terminal voltage difference groups, and the elapsed time, the relationship A second computing means,
Said second calculating means, if the said pattern determining means and aging pattern is pre Symbol second tracking pattern is determined, it calculates the linear correlation coefficient,
Said pattern determining means, wherein, when the linear correlation coefficient is 0.6 or more, the temporal change pattern before Symbol third terminal voltage difference Gunmata is the fourth terminal voltage difference group over time straight It is determined that the pattern increases linearly,
The second calculation means further calculates the curve correlation coefficient when the linear correlation coefficient is less than 0.6,
Said pattern determining means, wherein, when the curve correlation coefficient is 0.6 or more, the temporal change pattern before Symbol third terminal voltage difference Gunmata is the fourth terminal voltage difference group over time curve The battery module control device is characterized in that it is determined that the curve increase pattern increases as a result.

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