JP2014147139A - Storage battery system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage battery system capable of easily deciding the cause of a communication fault when the communication failure occurs.SOLUTION: A storage battery system 1 comprises: a storage battery 10 having battery modules 11a to 11d; voltage monitor circuits 20a to 20d arranged corresponding to battery modules 11a to 11d and for monitoring voltages of battery modules; and a battery controller 40 for controlling discharge and charge of the storage battery 10 based on the monitoring information obtained from the communication with voltage monitor circuits 20a to 20d. The battery controller 40 comprises: an abnormal position determination part 40a that when communication failure occurs between voltage monitor circuits 20a to 20d, calculates an estimated module voltage that is a voltage of a module section by using the monitoring information obtained from one of battery modules every predetermined module sections, and determines the abnormal position of the communication failure by comparing the estimated module voltage with the module voltage at module section after the communication failure.

Description

  The present invention relates to a storage battery system.

  The storage battery system includes a rechargeable storage battery (secondary battery) such as a lithium ion battery and a control device that controls charging / discharging of the storage battery, and is stored in the storage battery under the control of the control device. This is a system for taking out electric power and storing (charging / discharging) electric power in a storage battery. Such a storage battery system is used as a power source mounted on, for example, an electric vehicle (EV) or a hybrid vehicle (HV).

  Many of the storage batteries provided in the storage battery system have a configuration in which a battery module formed by connecting a plurality of battery cells (unit batteries) in series is connected in series as much as a required voltage is obtained. A storage battery system including such a storage battery includes a voltage monitoring circuit for each battery module constituting the storage battery, and the control device stores the storage battery while referring to monitoring information (monitoring data) of each voltage monitoring circuit. Control of taking out electric power and storing electric power in the storage battery (charge / discharge control) is performed.

  Patent Document 1 below discloses a conventional example of such a storage battery system. Specifically, in Patent Document 1 below, a plurality of lower controllers (cell controllers) that are provided corresponding to each battery module and control the battery cells that constitute the corresponding battery module, and an upper host that controls them. There is disclosed a storage battery system in which a controller (battery controller) is connected by daisy chain serial communication.

Japanese Patent Laid-Open No. 2008-220074

  By the way, the low-order controller provided in the storage battery system of Patent Document 1 described above operates by receiving power supply from the corresponding battery module to perform control of the battery cells and serial communication. For this reason, when an abnormality occurs in the storage battery, a failure occurs in serial communication between the upper controller and the lower controller due to, for example, the stop of power supply from the battery module to the lower controller. An abnormality of the storage battery occurs, for example, when a current path of the storage battery such as a breaker, a fuse, a CID (Current Interrupt Device), a power supply line, or the like provided in the storage battery is cut off (opened).

  In addition, although the power supply from the battery module to the lower controller is normally performed, if an abnormality occurs in the lower controller itself, the operation of the lower controller in which the abnormality occurs stops (or does not operate normally). ). For this reason, a failure occurs in the serial communication between the upper controller and the lower controller, as in the case where an abnormality occurs in the storage battery described above.

  As described above, the main causes of the failure in the serial communication between the upper controller and the lower controller are due to an abnormality of the storage battery and an abnormality of the lower controller. However, in the conventional storage battery system, when a failure occurs in the serial communication with the lower controller, there is a problem that the upper controller cannot determine the cause of the failure.

  This invention is made | formed in view of the said situation, and when a communication failure generate | occur | produces, it aims at providing the storage battery system which can determine the cause of the failure easily.

In order to solve the above problems, a storage battery system according to the present invention includes a storage battery having a plurality of battery modules formed by connecting battery cells in series, a voltage of the battery module provided corresponding to the battery module, and the battery module. A plurality of voltage monitoring circuits for monitoring at least one of the voltages of the battery cells, and charging of the storage battery based on monitoring information that is connected to the voltage monitoring circuit in a ring and communicates with the voltage monitoring circuit. In a storage battery system comprising a control device for controlling discharge, the control device monitors the battery module included in a predetermined module category when a communication failure occurs with the voltage monitoring circuit. The battery module monitoring information or the battery cell monitoring information obtained from the voltage monitoring circuit before the communication failure occurs. And calculating the estimated module voltage, which is the voltage of the module section, and comparing the estimated module voltage with the module voltage of the module section after the occurrence of the communication failure. It is characterized by comprising a judging means for judging the abnormal part.
Further, in the storage battery system of the present invention, the determination means is configured such that when the estimated module voltage is larger than the module voltage of the module classification after the communication failure occurs, the storage battery is It is characterized by determining that there is.
Further, in the storage battery system of the present invention, when the determination module has the estimated module voltage equal to or lower than the module voltage of the module section after the communication failure occurs, the voltage monitoring circuit It is characterized by determining that there is.
Here, in the storage battery system of the present invention, the determination means calculates the total number of the battery cells provided in the battery module included in the module section with respect to any one of the monitoring information of the battery module. The estimated module voltage is calculated by multiplying a value obtained by dividing by the number of battery cells provided in the battery module.
In the storage battery system of the present invention, the monitoring information of the battery module used for calculating the estimated module voltage is obtained before the communication failure occurs from the voltage monitoring circuit that monitors the battery module included in the module section. The voltage value of the obtained monitoring information of the battery module is the largest.
Alternatively, in the storage battery system of the present invention, the determination unit multiplies any one of the battery cell monitoring information by the total number of the battery cells provided in the battery module included in the module section. Thus, the estimated module voltage is calculated.
In the storage battery system according to the present invention, the monitoring information of the battery cell used for calculating the estimated module voltage is obtained before the communication failure occurs from the voltage monitoring circuit that monitors the battery module included in the module section. It is characterized in that the voltage value of the obtained battery cell monitoring information is the largest.
In addition, the storage battery system of the present invention includes a voltage detection circuit that detects a module voltage of the module section and outputs the module voltage to the control device.

  According to the present invention, when a communication failure with the voltage monitoring circuit occurs, the determination unit provided in the control device is configured to monitor the battery module included in the predetermined module classification. Using either one of the battery module monitoring information or the battery cell monitoring information obtained before the communication failure occurs, an estimated module voltage that is a voltage of the module classification is calculated, and the estimated module voltage and the communication failure are calculated. Since the abnormal part of the communication failure is determined by comparing with the module voltage of the module classification after the occurrence of the occurrence, there is an effect that the cause of the communication failure can be easily determined.

It is a block diagram which shows the principal part structure of the storage battery system by one Embodiment of this invention. It is a flowchart which shows the operation | movement at the time of the communication failure generation | occurrence | production of the storage battery system by one Embodiment of this invention. It is a timing chart for demonstrating operation | movement of the storage battery system by one Embodiment of this invention.

  Hereinafter, a storage battery system according to an embodiment of the present invention will be described in detail with reference to the drawings. Hereinafter, in order to facilitate understanding, a storage battery system mounted on an automobile such as an electric vehicle (EV) or a hybrid vehicle (HV) will be described as an example.

  FIG. 1 is a block diagram showing a main configuration of a storage battery system according to an embodiment of the present invention. As shown in FIG. 1, the storage battery system 1 of this embodiment includes a storage battery 10, voltage monitoring circuits 20a to 20d, voltage detection circuits 21a and 21b, insulating elements 30a to 30d, and a battery control device 40 (control device). The storage battery system 1 is connected to the inverter INV via the contactors C1 and C2, discharges the electric power stored in the storage battery 10 and supplies it to the inverter INV, and charges the storage battery 10 using regenerative power from the inverter INV. To do.

  Here, the contactors C1 and C2 are a kind of mechanical switch, and the space between the storage battery 10 and the inverter INV is opened or closed. The contactor C1 is provided between the positive terminal of the storage battery 10 and the inverter INV, and the contactor C2 is provided between the negative terminal of the storage battery 10 and the inverter INV. The inverter INV generates power for driving the motor M by driving the motor M with electric power supplied from the storage battery system 1. Further, the inverter INV supplies the electric power generated by the motor M to the storage battery system 1 as regenerative electric power by causing the motor M to function as a generator during deceleration of the automobile.

  The storage battery 10 includes battery modules 11 a to 11 d connected in series, a breaker 12, and a fuse 13, and discharges stored power and charges supplied power under the control of the battery control device 40. . The battery modules 11a to 11d are modules formed by connecting a plurality of battery cells C defined in advance in series. Here, the battery cell C is a unit battery provided in the battery modules 11a to 11d, and is a rechargeable storage battery (secondary battery) such as a lithium ion battery. In FIG. 1, the storage battery 10 including four battery modules 11 a to 11 d is illustrated for simplicity of explanation, but the number of battery modules provided in the storage battery 10 is arbitrary.

  The breaker 12 and the fuse 13 are connected in series between the battery module 11b and the battery module 11c, and are provided to cut off (open) the current path of the storage battery 10. For example, the breaker 12 is provided for an operator to manually cut off the current path of the storage battery 10. The fuse 13 is used to automatically cut off the current path of the storage battery 10 when an overcurrent flows through the storage battery 10. The position where the breaker 12 and the fuse 13 are provided is not necessarily between the battery modules 11b and 11c, and may be, for example, between the battery modules 11a and 11b, or between the battery modules 11c and 11d. .

  The voltage monitoring circuits 20a to 20d are provided corresponding to the battery modules 11a to 11d of the storage battery 10, and the voltage of the corresponding battery module (the voltage of the entire corresponding battery module) and each of the corresponding battery modules are provided. The voltage of the battery cell C is monitored. These voltage monitoring circuits 20a to 20d operate by receiving power from the corresponding battery modules 11a to 11d.

  The voltage monitoring circuits 20a to 20d are connected in cascade (daisy chain connection) to each other and connected to the battery control device 40 via the insulating elements 30a and 30b, and communicate with the battery control device 40 to perform the battery module and The monitoring information (monitoring data) of each battery cell C is transmitted to the battery control device 40. In FIG. 1, four voltage monitoring circuits 20 a to 20 d are illustrated for simplicity of explanation, but the same number of voltage monitoring circuits as the battery modules of the storage battery 10 are provided.

  The voltage detection circuits 21 a and 21 b detect the voltage of the battery module included in a predetermined category (module category) among the battery modules 11 a to 11 d provided in the storage battery 10. Specifically, the voltage detection circuit 21a is connected to the positive electrode of the battery module 11a and the negative electrode of the battery module 11b, and detects the voltage Vm1 (module voltage) of the battery modules 11a and 11b included in the first module section. To do. The voltage detection circuit 21b is connected to the positive electrode of the battery module 11c and the negative electrode of the battery module 11d, and detects the voltage Vm2 (module voltage) of the battery modules 11c and 11d included in the second module section. The voltage detection circuits 21a and 21b are connected to the battery control device 40 via the insulating elements 30c and 30d, respectively, and output detection information (detection data) of the voltages Vm1 and Vm2 to the battery control device 40.

  The insulating elements 30a and 30b are elements for electrically insulating the daisy chain-connected voltage monitoring circuits 20a to 20d and the battery control device 40, and are realized by, for example, photocouplers. The insulating element 30a is provided between the battery control device 40 and the voltage monitoring circuit 20a, and the insulating element 30b is provided between the battery control device 40 and the voltage monitoring circuit 20d. The insulating elements 30c and 30d are elements for electrically insulating the voltage detection circuits 21a and 21b and the battery control device 40, respectively, and are realized by, for example, photocouplers.

  The battery control device 40 controls charging / discharging of the storage battery 10 based on the monitoring information of the voltage monitoring circuits 20a to 20d. Specifically, the battery control device 40 obtains the remaining capacity (SOC: State Of Charge) of the storage battery 10 from the monitoring information of the voltage monitoring circuits 20a to 20d, and the obtained remaining capacity is within a predetermined allowable range. The charging / discharging of the storage battery 10 is controlled according to the running state of the automobile. For example, when driving the motor M to generate power for running the vehicle, control is performed to discharge the electric power stored in the storage battery 10, and when the vehicle is decelerated, the power is supplied from the inverter INV. Control which charges storage battery 10 with regenerative electric power is performed.

  In addition, when a communication failure occurs between the voltage monitoring circuits 20a to 20d, the battery control device 40 determines the location (abnormal location) that is the cause of the communication failure as an abnormal location determination unit 40a (determination means). Is provided. The abnormal point determination unit 40a may be realized as a hardware circuit. When software that realizes the abnormal point determination unit 40a is read into a computer, the software and hardware resources cooperate with each other. It may be realized.

  The abnormal point determination unit 40a calculates estimated module voltages that are estimated to be the voltages of the first and second module sections described above when a communication failure occurs between the voltage monitoring circuits 20a to 20d. . Then, the abnormal point determination unit 40a determines the abnormal point by comparing the calculated estimated module voltage for each of the first and second module sections with the voltage of the first and second module sections.

  Specifically, the abnormal point determination unit 40a monitors the battery modules 11a and 11b included in the first module classification described above when a communication failure with the voltage monitoring circuits 20a to 20d occurs. Estimated that the voltage of the first module section is estimated by using any one of the monitoring information of the battery module or the monitoring information of the battery cell C obtained before the communication failure occurs from the circuits 20a and 20b. The module voltage Vp1 is calculated. Then, the abnormal point determination unit 40a determines the abnormal point by comparing the calculated estimated module voltage Vp1 with the voltage of the first module section (the voltage Vm1 detected by the voltage detection circuit 21a).

  In addition, the abnormal point determination unit 40a monitors the battery modules 11c and 11d included in the second module classification described above when a communication failure occurs between the voltage monitoring circuits 20a to 20d. , 20d, the estimated module voltage estimated to be the voltage of the second module section using either the battery module monitoring information or the battery cell C monitoring information obtained before the communication failure occurs. Vp2 is calculated. Then, the abnormal part determination unit 40a compares the calculated estimated module voltage Vp2 with the voltage of the second module section (voltage Vm2 detected by the voltage detection circuit 21b) to determine the abnormal part.

  Here, when the estimated module voltage Vp1 is larger than the voltage Vm1 detected by the voltage detection circuit 21a, the abnormal location determination unit 40a determines that the battery modules 11a and 11b of the storage battery 10 are abnormal locations. . This is because when the cause of the communication failure is an abnormality of the battery modules 11a and 11b (for example, interruption of a current path by an unillustrated overcurrent interruption device provided in each of the battery cells C), the voltage detection circuit 21a. This is because the voltage Vm1 of the first module section detected in (1) is significantly lower than the voltage of the first module section (approximately the same voltage as the estimated module voltage Vp1) before the abnormality occurs.

  Further, when the estimated module voltage Vp2 is higher than the voltage Vm2 detected by the voltage detection circuit 21b, the abnormal location determination unit 40a determines that the battery modules 11c and 11d of the storage battery 10 are abnormal locations. When the cause of the communication failure is an abnormality of the battery modules 11c and 11d (for example, the interruption of the current path by the above-described unillustrated overcurrent interruption device), the second detection detected by the voltage detection circuit 21b. This is because the voltage Vm2 in the module section is significantly lower than the voltage in the second module section (approximately the same voltage as the estimated module voltage Vp2) before the abnormality occurs.

  On the other hand, in the abnormal point determination unit 40a, the estimated module voltage Vp1 is equal to or lower than the voltage Vm1 detected by the voltage detection circuit 21a, and the estimated module voltage Vp2 is equal to or lower than the voltage Vm2 detected by the voltage detection circuit 21b. In this case, it is determined that the voltage monitoring circuits 20a to 20d are abnormal places. This is because when the cause of the communication failure is due to an abnormality in the voltage monitoring circuits 20a to 20d, the voltages Vm1 and Vm2 of the first and second module sections detected by the voltage detection circuits 21a and 21b are almost fluctuated. This is because the voltage is maintained at the same level as the voltage before the occurrence of the abnormality (substantially the same voltage as the estimated module voltages Vp1 and Vp2).

Here, as described above, the calculation methods of the estimation module voltages Vp1 and Vp2 include the following first calculation method and second calculation method.
First calculation method: Method using each one of the battery module monitoring information obtained for each of the first and second module sections. Second calculation method: First and second module sections. Of calculating using any one of the monitoring information of the battery cell C obtained for each of the above

  In the case of using the first calculation method described above, the abnormal point determination unit 40a uses the one having the largest voltage value among the battery module monitoring information obtained for each of the first and second module sections. The voltages Vp1 and Vp2 are calculated respectively. Specifically, the abnormal point determination unit 40a is a battery module monitoring information obtained before a communication failure occurs from the voltage monitoring circuits 20a and 20b that monitor the battery modules 11a and 11b included in the first module section. The estimated module voltage Vp1 is calculated using the one of the voltages (Va, Vb) having the largest voltage value. Similarly, of the battery module monitoring information (voltages Vc, Vd) obtained before the communication failure occurs from the voltage monitoring circuits 20c, 20d that monitor the battery modules 11c, 11d included in the second module section. The estimated module voltage Vp2 is calculated using the one having the largest voltage value.

For example, for the first module section, the monitoring information (voltage Va) of the battery module 11a monitored by the voltage monitoring circuit 20a is the largest, and for the second module section, the battery monitored by the voltage monitoring circuit 20c. Assuming that the monitoring information (voltage Vc) of the module 11c is the largest, the abnormal point determination unit 40a calculates estimated module voltages Vp1 and Vp2 using the following equations (1) and (2), respectively.
Vp1 = (N1 / n1) · α · Va (1)
Vp2 = (N2 / n2) · α · Vc (2)

  However, “N1” in the above formula (1) is the total number of battery cells C provided in the battery modules 11a and 11b included in the first module section, and “n1” is the battery module 11a (the largest voltage). This is the number of battery cells C that form a battery module from which Va is obtained. In the above equation (2), “N2” is the total number of battery cells C provided in the battery modules 11c and 11d included in the second module section, and “n2” is the battery module 11c (the largest voltage Vc is It is the number of battery cells C forming the battery module obtained. Further, the coefficient α in the above equations (1) and (2) is a variation coefficient determined in consideration of variations in the voltage value of the battery cell C provided in the storage battery 10. For example, the coefficient α is obtained by previously detecting the maximum voltage and the minimum value of the voltage in the normal state of each battery cell C provided in the storage battery 10 and setting the difference voltage ΔV to determine the design minimum value of the battery cell C. It is obtained by dividing by the difference voltage ΔV.

  That is, the abnormal point determination unit 40a is provided with the total number of battery cells C provided in the battery modules 11a and 11b with respect to the voltage Va (maximum voltage) indicating the monitoring information of the battery module 11a. The estimated module voltage Vp1 is calculated by multiplying the value (N1 / n1) obtained by dividing the number of battery cells C by the variation coefficient (α). Similarly, the abnormal location determination unit 40a is provided with the total number of battery cells C provided in the battery modules 11c and 11d with respect to the voltage Vc (the largest voltage) indicating the monitoring information of the battery module 11c. The estimated module voltage Vp2 is calculated by multiplying the value (N2 / n2) obtained by dividing by the number of battery cells C and the variation coefficient (α).

  On the other hand, in the case of using the second calculation method described above, the abnormal point determination unit 40a has the largest voltage value in the monitoring information of the battery cell C obtained for each of the first and second module sections. Are used to calculate estimated module voltages Vp1, Vp2, respectively. Specifically, the abnormal point determination unit 40a monitors the battery cell C obtained before a communication failure occurs from the voltage monitoring circuits 20a and 20b that monitor the battery modules 11a and 11b included in the first module section. The estimated module voltage Vp1 is calculated using the information having the largest voltage value. Similarly, the voltage value of the monitoring information of the battery cell C obtained before the occurrence of the communication failure from the voltage monitoring circuits 20c and 20d that monitor the battery modules 11c and 11d included in the second module section is the highest. The estimated module voltage Vp2 is calculated using a larger one.

For example, regarding the first module section, it is assumed that the voltage (voltage Vq1) of one battery cell C constituting the battery module 11a monitored by the voltage monitoring circuit 20a is the largest, and for the second module section, the voltage monitoring circuit Assuming that the voltage (voltage Vq2) of one battery cell C constituting the battery module 11c monitored at 20c is the largest, the abnormal point determination unit 40a uses the following equations (3) and (4) to estimate the module voltage Vp1 and Vp2 are calculated respectively.
Vp1 = N1 · α · Vq1 (3)
Vp2 = N2 · α · Vq2 (4)

  That is, the abnormal point determination unit 40a is provided in the battery modules 11a and 11b with respect to any one of the monitoring information of each battery cell C (the largest voltage Vq1) obtained from the voltage monitoring circuits 20a and 20b. The estimated module voltage Vp1 is calculated by multiplying the total number (N1) of the battery cells C by the variation coefficient (α). Similarly, the total number of battery cells C provided in the battery modules 11c and 11d with respect to any one (the largest voltage Vq2) of the monitoring information of each battery cell C obtained from the voltage monitoring circuits 20c and 20d ( N2) and the variation coefficient (α) are multiplied to calculate the estimated module voltage Vp2.

  Next, operation | movement of the storage battery system 1 in the said structure is demonstrated. FIG. 2 is a flowchart showing an operation when a communication failure occurs in the storage battery system according to the embodiment of the present invention. FIG. 3 is a timing chart for explaining the operation of the storage battery system according to the embodiment of the present invention. Hereinafter, after briefly explaining the operation when the communication failure between the voltage monitoring circuits 20a to 20d and the battery control device 40 does not occur, the operation when the communication failure occurs will be described. In the following, it is assumed that the abnormal point determination unit 40a of the battery control device 40 calculates the estimated module voltages Vp1 and Vp2 by the above-described first calculation method.

  First, when a communication failure has not occurred, communication is periodically performed between the voltage monitoring circuits 20a to 20d and the battery control device 40, and the monitoring information of the voltage monitoring circuits 20a to 20d is battery control. It is periodically acquired by the device 40 (see “Voltage Va to Vd” in FIG. 3). Further, in the battery control device 40, the voltages Vm1 and Vm2 detected by the voltage detection circuits 21a and 21b are periodically acquired separately from the monitoring information of the voltage monitoring circuits 20a to 20d (“Voltage” in FIG. 3). Vm1, Vm2 ").

  When the monitoring information of the voltage monitoring circuits 20a to 20d is acquired, the battery control device 40 obtains the remaining capacity of the storage battery 10, and if the obtained remaining capacity is within a predetermined allowable range, the battery control apparatus 40 responds to the driving state of the vehicle. The charge / discharge of the storage battery 10 is controlled. For example, when driving the motor M to generate power for running the vehicle, control is performed to discharge the electric power stored in the storage battery 10, and when the vehicle is decelerated, the power is supplied from the inverter INV. Control which charges storage battery 10 with regenerative electric power is performed. If no communication failure has occurred, the above operation is repeated.

  Next, when a communication failure occurs, as shown in FIG. 3, the communication error flag, which is a flag indicating that a communication error has occurred, is changed from “L (low)” level to “H” in the battery control device 40. (High) ”level (time t2). Then, the abnormal point determination unit 40a provided in the battery control device 40 uses the estimated module voltage using any one of the battery module monitoring information obtained from the voltage monitoring circuits 20a and 20b before the communication failure occurs. Vp1 is calculated, and the estimated module voltage Vp2 is calculated using any one of the battery module monitoring information obtained from the voltage monitoring circuits 20c and 20d before the communication failure occurs (step S11).

  Specifically, the abnormal point determination unit 40a has the largest voltage value among the voltages Va and Vb obtained at time t1 immediately before time t2 when the communication error flag changes from the “L” level to the “H” level. An estimated module voltage Vp1 is calculated using the monitoring information. Moreover, the estimated module voltage Vp2 is calculated using the monitoring information having the largest voltage value among the voltages Vc and Vd obtained at time t1. For example, the abnormal point determination unit 40a calculates the estimated module voltage Vp1 using the above-described equation (1) when the voltage Va is larger than the voltage Vb, and when the voltage Vc is larger than the voltage Vd, The estimated module voltage Vp2 is calculated using the above-described equation (3).

  When the estimated module voltages Vp1 and Vp2 are calculated, the voltages Vm1 and Vm2 detected by the voltage detection circuits 21a and 21b are acquired by the battery control device 40 (step S12: time t3). When the voltages Vm1 and Vm2 are acquired, the abnormality determination flag, which is a flag indicating that the abnormality determination is performed, is set from “L” level to “H” in the battery control device 40 at the same time (or almost simultaneously). Change to level. Then, whether or not the estimated module voltage Vp1 calculated in step S11 is larger than the voltage Vm1 acquired in step S12, and the estimated module voltage Vp2 calculated in step S11 is greater than the voltage Vm2 acquired in step S12. Is determined by the abnormal point determination unit 40a (step S13).

  When it is determined that the estimated module voltage Vp1 is greater than the voltage Vm1, or when it is determined that the estimated module voltage Vp2 is greater than the voltage Vm2 (when the determination result in step S13 is “YES”). The abnormal part determination unit 40a determines that the storage battery 10 is abnormal (step S14). Specifically, when the abnormal part determination unit 40a determines that the estimated module voltage Vp1 is greater than the voltage Vm1, the abnormal part determination unit 40a determines that the battery modules 11a and 11b of the storage battery 10 are abnormal, and the estimated module voltage Vp2 Is determined to be higher than the voltage Vm2, it is determined that the battery modules 11c and 11d of the storage battery 10 are abnormal.

  On the other hand, when it is determined that the estimated module voltage Vp1 is equal to or lower than the voltage Vm1 and the estimated module voltage Vp2 is equal to or lower than the voltage Vm2 (when the determination result in step S13 is “NO”), the abnormal point determination unit 40a determines that the voltage detection circuits 20a to 20d are abnormal (step S15). In this manner, an abnormal location is determined when a communication failure occurs between the voltage monitoring circuits 20a to 20d and the battery control device 40.

  Even when the abnormal part determination unit 40a of the battery control device 40 calculates the estimated module voltages Vp1 and Vp2 by the second calculation method described above, the abnormal part is determined according to the process of the flowchart shown in FIG. Is called. In such a case, only the specific calculation processing of the estimated module voltages Vp1 and Vp2 performed in step S11 in FIG. 2 is different.

  As described above, in the present embodiment, when the communication error flag changes from the “L” level to the “H” level in the battery control device 40, the voltage monitoring circuits 20a and 20b obtain the change before the communication error flag changes. The estimated module voltages Vp1 and Vp2 are calculated using any one of the obtained monitoring information and any one of the monitoring information obtained from the voltage monitoring circuits 20c and 20d, respectively. The generated voltage Vm1 is compared, and the estimated module voltage Vp2 is compared with the voltage Vm2 after the occurrence of the communication failure, and the abnormal location determination unit 40a determines the abnormal location of the communication failure. For this reason, when a communication failure occurs, it is possible to easily determine the cause of the failure.

  As mentioned above, although the storage battery system by one Embodiment of this invention was demonstrated, this invention is not restrict | limited to embodiment mentioned above, It can change freely within the scope of the present invention. For example, in the above embodiment, the case where two battery modules are included in each of the first and second module sections has been described as an example. However, one or more battery modules are included in the module sections. There may be. Further, the number of module sections defined in the storage battery 10 may be one or three or more.

  Moreover, in the said embodiment, in order to understand easily, the storage battery system mounted in motor vehicles, such as an electric vehicle (EV) and a hybrid vehicle (HV), was mentioned as an example and demonstrated. However, the present invention can also be applied to a storage battery system provided in a moving body such as a motorcycle other than an automobile or a ship.

DESCRIPTION OF SYMBOLS 1 ... Storage battery system, 10 ... Storage battery, 11a-11d ... Battery module, 20a-20d ... Voltage monitoring circuit, 21a, 21b ... Voltage detection circuit, 40 ... Battery control apparatus, 40a ... Abnormal location determination part, C ... Battery cell

Claims (8)

A storage battery having a plurality of battery modules formed by connecting battery cells in series, and a plurality of batteries that are provided corresponding to the battery modules and that monitor at least one of the voltage of the battery modules and the voltage of the battery cells forming the battery modules In a storage battery system comprising: a voltage monitoring circuit; and a control device that controls the charging and discharging of the storage battery based on monitoring information that is connected to the voltage monitoring circuit in a ring and communicates with the voltage monitoring circuit.
When a communication failure occurs between the control device and the voltage monitoring circuit, before the communication failure occurs from the voltage monitoring circuit that monitors the battery module included in a predetermined module section. Using any one of the obtained battery module monitoring information or battery cell monitoring information, an estimated module voltage, which is a voltage of the module section, is calculated, and the estimated module voltage and the communication failure occur. A storage battery system comprising: a determination unit that compares a module voltage of the module classification later to determine an abnormal portion of the communication failure.   The determination means determines that the storage battery is the abnormal location when the estimated module voltage is larger than the module voltage of the module classification after the communication failure has occurred. The storage battery system according to claim 1.   The determination unit determines that the voltage monitoring circuit is the abnormal portion when the estimated module voltage is equal to or lower than the module voltage of the module classification after the communication failure occurs. The storage battery system according to claim 1 or 2.   The battery cell provided in the battery module includes a total number of the battery cells provided in the battery module included in the module classification for any one of the monitoring information of the battery module. The storage battery system according to any one of claims 1 to 3, wherein the estimated module voltage is calculated by multiplying a value obtained by dividing by a number of.   The battery module monitoring information used for calculating the estimated module voltage is obtained from the voltage monitoring circuit that monitors the battery modules included in the module section before the communication failure occurs. The storage battery system according to claim 4, wherein the monitoring information has the largest voltage value.   The determination means calculates the estimated module voltage by multiplying any one of the battery cell monitoring information by the total number of the battery cells provided in the battery module included in the module section. The storage battery system according to any one of claims 1 to 3, wherein:   The battery cell monitoring information used for calculation of the estimated module voltage is the battery cell obtained before the communication failure occurs from the voltage monitoring circuit that monitors the battery module included in the module section. The storage battery system according to claim 6, wherein the monitoring information has the largest voltage value.   The storage battery system according to any one of claims 1 to 7, further comprising a voltage detection circuit that detects a module voltage of the module section and outputs the module voltage to the control device.

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