JP4835570B2 - Voltage detection device for battery pack - Google Patents

Description

  The present invention detects the voltage of a unit battery of a unit battery that is either a single battery cell or a plurality of adjacent battery cells in an assembled battery configured as a series connection body of a plurality of battery cells. The present invention relates to an assembled battery voltage detection device including detection means for performing the above operation.

  As this type of voltage detection device, for example, as shown in Patent Document 1 below, a device including a detection unit that selectively connects a battery module composed of an equal number of battery cells to a flying capacitor via a multiplexer. Proposed. That is, when a specific battery module is selected by the multiplexer, the flying capacitor is charged until the voltage of the selected battery module is reached. For this reason, the voltage of a battery module is detectable with the voltage of a flying capacitor.

  On the other hand, since the voltage between the electrodes of the assembled battery is very large, when a member comes into contact with an on-vehicle high-voltage system configured with the assembled battery, for example, during vehicle maintenance, the assembled battery It is desirable to prevent the voltage across the two terminals from being applied.

Therefore, conventionally, for example, as shown in Patent Document 2 below, it has also been proposed and put into practical use to provide a service plug at the center of the assembled battery. The service plug is a plug having a function of bringing adjacent battery cells into a conductive state in the central portion of the assembled battery. Then, at the time of maintenance or the like, the assembled battery is divided into two series connected bodies of battery cells by removing the service plug. As a result, even if any member comes into contact with the in-vehicle high-voltage system configured with the assembled battery, the voltage value applied to this member can be halved.
JP 2002-289263 A JP 2001-320801 A

  In the case where the service plug is provided, when a current flows through the assembled battery when the voltage of the battery module is detected using the flying capacitor, a voltage drop due to the service plug becomes a voltage module voltage detection error. Moreover, when the resistance value of the service plug increases, there is a possibility that the charging / discharging process of the assembled battery may be hindered.

  Note that, in general, the battery pack is not limited to the one provided with the service plug, and such a problem that causes inconvenience due to the connection means between the battery cells constituting the battery pack is generally common.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a single battery cell in a battery pack configured as a series connection body of a plurality of battery cells and a battery including several adjacent batteries. An object of the present invention is to provide an assembled battery voltage detection device that can cope with the disadvantages caused by connecting means for connecting the unit batteries of any of the cells.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

The invention described in claim 1 relates to a unit battery that is one of a single battery cell and a plurality of adjacent battery cells in an assembled battery configured as a series connection body of a plurality of battery cells. In the assembled battery voltage detecting device including the detecting means for detecting the voltage of the unit battery, the specific unit cells adjacent to each other among the unit cells are different in structure from the connecting means for connecting other unit cells adjacent to each other. heterogeneous connections are connected by means, connecting lines for connecting the detection means and the unit batteries includes a connection line connected to respective opposite ends of the heterogeneity connecting means, the extraneous connecting means Comprises a conduction control means for conducting and blocking between the specific unit cells, and one or more unit cells connected to any terminal of the heterogeneous connection means and the heterogeneous connection means The heterogeneous connection means based on a detection value of voltage by connecting both ends of the column connection body to the detection means and a detection value of voltage by connecting both ends of the one or more unit cells to the detection means. And means for grasping at least one characteristic of the detecting means .

  The connection means for connecting the battery cells constituting the assembled battery tends not to be the same. For example, when the voltage at both ends of the assembled battery is very high, a service plug is provided assuming that a member may inadvertently come into contact with the assembled battery during maintenance or the like. There is a structural difference with connection means that are not. In addition, when the assembled battery becomes very long, a conductor (bus bar) having a large cross-sectional area that connects the rows with a low resistance is provided in order to arrange them in a plurality of rows due to space restrictions when mounted on a vehicle. May be used. In this case, there is a structural difference between the connecting means including the bus bar and the connecting means that does not. Thus, the connection means for connecting the battery cells (unit batteries) tends to include a heterogeneous connection means. And since the heterogeneous connection means is different from others, detection error tends to be a problem when the voltage of the unit battery is detected by a closed loop circuit including the heterogeneous connection means. In addition, since the heterogeneous connection means is different from others, it is considered that the probability of occurrence of an abnormality is higher than that of other connection means.

  In this regard, in the above-described invention, since the connection line that connects the both ends of the heterogeneous connection means and the detection means is provided, it is possible to appropriately cope with the disadvantage caused by the heterogeneous connection means.

In addition, if the continuity control means is a member that can be mechanically operated for continuity and interruption, the voltage across the assembled battery is applied to this member even if any member contacts the assembled battery during maintenance or the like. Can be avoided. Further, if the conduction control means is a fuse or the like, it is possible to prevent an excessive current from flowing through the assembled battery. However, this conduction control means is likely to cause a detection error when detecting the voltage of the unit battery by a closed loop circuit including the conduction control means, and is considered to have a higher probability of occurrence of an abnormality than other connection means. For this reason, the technical significance of connecting a connection line to each of both ends of the heterogeneous connection means is great.

Further, if connection lines connected to both ends of the heterogeneous connection means are used, a closed loop circuit including the heterogeneous connection means and the detection means (one or a plurality of unit cells connected to any terminal of the heterogeneous connection means and A circuit formed by connecting both ends of a serially connected body with the heterogeneous connection means to the detection means), or a closed loop circuit including the unit battery and the detection means adjacent to the heterogeneous connection means and not including the heterogeneous connection means (1 or above) By forming a circuit by connecting both ends of a plurality of unit batteries to the detection means, it is possible to detect a voltage at a predetermined part by the detection means. Thus, for example, based on the voltage detected by the loop path that does not include a closed loop circuit including a heterogeneous connection means can grasp characteristics and heterogeneity connecting means, the characteristics of the detection means.

According to a second aspect of the invention of claim 1 Symbol placement, the threshold above which the current flowing through the battery pack is set on the basis of the lower limit resistance value detectable current amount with high accuracy of the heterogeneous connection means In this case, the detected value of the voltage by connecting both ends of a series connection body of one or more unit batteries connected to any terminal of the heterogeneous connection means and the heterogeneous connection means to the detection means, and The apparatus further comprises estimation means for estimating a resistance value of the heterogeneous connection means based on a detected voltage value obtained by connecting both ends of the one or more unit cells to the detection means .

  The situation where the change in the voltage of the one or more unit cells is less than or equal to a specified value (a value that can be ignored) between the voltage detection by the closed loop circuit including the heterogeneous connection means and the voltage detection by the closed loop circuit not including the heterogeneous connection means. Underneath, the difference in voltage detected by these two closed loop circuits is thought to be due to a voltage drop by the heterogeneous connection means. For this reason, the resistance value of the heterogeneous connection means can be estimated based on the current flowing through the heterogeneous connection means.

According to a third aspect of the present invention, in the second aspect of the present invention, the detection means includes a plurality of circuits that detect a voltage between a pair of connection lines of the connection lines, and the estimation means includes the heterogeneity. The one or more unit cells by connecting both ends of a series connection body of one or more unit cells connected to any one terminal of the connection means and the heterogeneous connection means to one of the plurality of circuits. of the voltage detection, the one or both ends of the plurality of unit cells by performing said by connecting to another one of the plurality of circuit 1 or more of the unit cells and a voltage detected simultaneously, the resistance value It is characterized by performing estimation.

  In the above invention, since a plurality of circuits for detecting voltage are provided, a closed loop circuit including one of the plurality of circuits and the heterogeneous connection means and a closed loop circuit including another one of the plurality of circuits and the heterogeneous connection means are formed simultaneously. can do. For this reason, the voltage of the said 1 or several unit battery can be detected simultaneously, and, by extension, the change of the voltage of the said 1 or several unit battery at the time of these two detections can be eliminated. For this reason, the resistance value can be estimated with high accuracy.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the detection means includes a plurality of circuits for detecting a voltage between a pair of connection lines of the connection lines. If the current flowing through the assembled battery is less than a threshold value set based on the lower limit of the amount of current that can detect the resistance value of the heterogeneous connection means with high accuracy, the current is connected to one of the terminals of the heterogeneous connection means. Voltage detection of the one or more unit cells by connecting both ends of a series connection body of the one or more unit cells and the heterogeneous connection means to one of the plurality of circuits, and the one or more unit cells The apparatus further comprises means for diagnosing whether or not the detecting means is abnormal by simultaneously performing voltage detection of the one or more unit batteries by connecting both ends of the unit battery to another one of the plurality of circuits. It is characterized by that.

  In the above invention, since a plurality of circuits for detecting voltage are provided, a closed loop circuit including one of the plurality of circuits and the heterogeneous connection means and a closed loop circuit including another one of the plurality of circuits and the heterogeneous connection means are formed simultaneously. can do. At this time, if the current flowing through the heterogeneous connection means is less than a predetermined value, the influence of the voltage drop amount at the heterogeneous connection means is small. It is thought to be caused. In the above invention, paying attention to this point, it is possible to diagnose the presence or absence of abnormality of the detection means.

(First embodiment)
Hereinafter, an embodiment in which a battery pack voltage detection device according to the present invention is applied to a vehicle-mounted high-voltage battery voltage detection device will be described with reference to the drawings.

  FIG. 1 shows an overall configuration of a voltage detection system for an in-vehicle high voltage battery according to the present embodiment.

  The assembled battery 10 as an in-vehicle high-voltage battery is configured as a series connection body of battery cells 12 which is the minimum unit of charge and discharge. The assembled battery 10 supplies electric power to the electric motor through, for example, an inverter. Further, for example, power is supplied to the vehicle-mounted low-voltage battery via a DC-DC converter. The battery cell 12 is divided into 12 blocks B0 to B11 each having N (≧ 2) adjacent to each other.

  The voltage between both electrodes of these blocks B0 to B11 is detected by the microcomputer (microcomputer 30) by operating the detection unit 20. The detection unit 20 includes detection lines L0 to L12, and the positive and negative electrodes of each block Bi (i = 0 to 11) are connected to the detection line Li and the detection line L (i + 1), respectively. These detection lines L0 to L12 are connected to three input lines IN1 to IN3 via a multiplexer MPX. The multiplexer MPX includes sampling switches SW0 to SW12 made of, for example, SSR (Solid State Relay) corresponding to the detection lines L0 to L12. The detection lines L0 to L12 are assigned to the input lines IN1 to IN3 via the sampling switches SW0 to SW12.

  A detection circuit DC is connected to the input lines IN1 to IN3. Specifically, a flying capacitor 22 is connected between the input line IN1 and the input line IN2, and a flying capacitor 23 is connected between the line IN2 and the line IN3. The lines IN1 to IN3 are connected to the input terminals T1 to T4 of the differential amplifier circuits A and B via sampling switches SWa to SWc made of, for example, SSR (Solid State Relay). That is, the input line IN1 is connected to the input terminal T1 of the differential amplifier circuit B via the sampling switch SWa, and the input line IN2 is connected to the input terminal T2 of the differential amplifier circuit B via the sampling switch SWb. It is connected to the input terminal T3 of the dynamic amplifier circuit A. The input line IN3 is connected to the input terminal T4 of the differential amplifier circuit A via the sampling switch SWc. Thus, the input terminal T2 of the differential amplifier circuit B and the input terminal T3 of the differential amplifier circuit A are short-circuited.

  Outputs of the differential amplifier circuits A and B are taken into the A / D converter 26. The A / D converter 26 converts analog data output from the differential amplifier circuits A and B into digital data and outputs the digital data to the microcomputer 30.

  The microcomputer 30 operates the sampling switches SW0 to SW12 and the sampling switches SWa to SWc to read the voltages between the respective electrodes of the blocks B0 to B11 via the differential amplifier circuits A and B. At this time, the output voltage of the differential amplifiers A and B determined appropriately according to the block Bi to be detected is recognized as a true voltage. This is because the lines L2 to L5 and L7 to L11 for detecting the voltages of the blocks B0 to B11 are shared by two of the adjacent blocks B0 to B5 and B7 to B11. That is, for example, the line L2 is positive when detecting the voltage of the block B1, but is negative when detecting the voltage of the block B2. Therefore, the input line IN3 that is in a conductive state with this also becomes a positive electrode when the voltage of the block B1 is detected, but becomes a negative electrode when the voltage of the block B2 is detected. Therefore, the microcomputer 30 recognizes the correct polarity as the voltage value output from the differential amplifier circuits A and B depending on which block Bi is the detection target.

  The microcomputer 30 also has a function of grasping the charging current and discharging current by taking in the detection value of the current sensor 40 that detects the current flowing through the assembled battery 10.

  The assembled battery 10 is provided with a service plug SP between the positive terminal of the block B5 and the negative terminal of the block B6, which is the central part. As a result, for example, when maintenance is desired and the insulation of the loop circuit including the assembled battery 10 is desired to be increased, the service plug SP is opened, so that any member contacts both ends of the assembled battery 10. Even so, the assembled battery 10 can be divided into a series connection of blocks B0 to B5 and a series connection of blocks B6 to B11.

  However, since the service plug SP is used for the connection between the block B5 and the block B6, the connection means between the block B5 and the block B6 is structurally different from the connection means between other adjacent blocks. . Therefore, for example, when the negative terminal of the block B5 and the positive terminal of the service plug SP are connected to the detection circuit DC in order to detect the voltage across the block B5, the voltage drop due to the service plug SP There is a risk of B5 voltage detection error.

  Therefore, in the present embodiment, as shown in FIG. 1, the detection lines L6a and L6b are connected to both ends of the service plug SP. Thereby, when detecting the voltage across the block B5 by forming a closed loop circuit including the block B5 and the detection circuit DC, or forming the closed loop circuit including the block B6 and the detection circuit DC, When detecting the voltage, these closed loop circuits can be configured without including the service plug SP.

  Further, in the present embodiment, by using a configuration in which the detection lines L6a and L6b are connected to both ends of the service plug SP, a process for diagnosing whether or not the service plug SP is abnormal or whether or not the detection circuit DC is abnormal is also performed. Here, as an abnormality of the service plug SP, for example, there may be an abnormality in which the conductivity of the service plug SP decreases due to foreign matters entering when the service plug SP is temporarily removed and then fitted again during maintenance. Further, as the abnormality of the detection circuit DC, for example, secular change can be considered.

  FIG. 2 shows aspects of voltage detection processing of blocks B0 to B11 and abnormality diagnosis processing of the service plug SP and detection circuit DC in the present embodiment.

  As shown in the figure, in the present embodiment, voltage detection of the blocks B0 to B11 is performed as follows. First, by turning on three adjacent sampling switches SWi, SW (i + 1), and SW (i + 2), the flying capacitors 22 and 24 are charged in two blocks Bi and B (i + 1) adjacent to each other. Next, the sampling amplifiers SWi, SW (i + 1), and SW (i + 2) are turned off, and the sampling switches SWa to SWc are turned on, whereby the differential amplifier circuits A and B detect the voltage. FIG. 2 shows an example in which these processes are sequentially performed from the voltage detection of the blocks B0 and B1. Here, the voltage of the block B5 is detected by turning on the sampling switches SW5 and SW6a, and the voltage of the block B6 is detected by turning on the sampling switches SW6b and SW7.

  When the voltage detection of the blocks B10 and B11 is completed in this way, the sampling switches SW6a, SW6b, and SW7 are turned on to perform the abnormality diagnosis. Thus, the detection lines L6b and L7 are connected to both electrodes of the flying capacitor 22, and the detection lines L6a and L7 are connected to both electrodes of the flying capacitor 24. That is, in this case, the voltage difference between the flying capacitors 22 and 24 can be approximately approximated by the voltage drop of the service plug SP. By paying attention to this point, abnormality diagnosis is performed by the processing shown in FIG.

  FIG. 3 shows the procedure of the abnormality diagnosis process. This process is repeatedly executed by the microcomputer 30 when the voltage detection process of the blocks B0 to B11 is completed.

  In this series of processing, first, in step S10, the voltage V6a of the flying capacitor 24 due to the on operation of the sampling switches SW6a and SW7 is detected by the differential amplifier circuit A, and the flying capacitor 22 of the flying capacitor 22 by the on operation of the sampling switches SW6b and SW7 is detected. The voltage V6b is detected by the differential amplifier circuit B. In the subsequent step S12, it is determined whether or not the current detected by the current sensor 40 is greater than or equal to the threshold value α when the voltage is detected. More precisely, it is determined whether or not the current when the sampling switches SW6a, SW6b, and SW7 are turned on is greater than or equal to the threshold value α. This process is for determining whether or not there is a sufficient difference between the voltages V6a and V6b to accurately detect the resistance value due to the voltage drop of the service plug SP. Here, the threshold value α is set based on the lower limit value of the current amount that enables the resistance value of the service plug SP to be detected with high accuracy.

  If a positive determination is made in step S12, the process proceeds to step S14. In step S14, the resistance value R of the service plug SP is calculated. This can be done by dividing the difference between the voltages V6a and V6b by the current value when these voltages are detected. In the following step S16, it is determined whether or not the resistance value R of the service plug SP is excessively separated from the reference resistance value (reference resistance value Rs). Specifically, it is determined whether or not the absolute value of the difference between the ratio of the resistance value R to the reference resistance value Rs and “1” is equal to or greater than the threshold value γ. If an affirmative determination is made in step S16, it is determined in step S18 that there is an abnormality in the service plug SP.

  On the other hand, when a negative determination is made in step S12, the process proceeds to step S20. In step S20, the presence or absence of abnormality of the detection circuit DC is diagnosed based on whether or not the difference between the voltages V6a and V6b is greater than or equal to a predetermined value. Here, it is noted that the difference between the voltages V6a and V6b can be ignored if the detection circuit DC is normal because the current flowing through the service plug SP is small. That is, when the difference between the voltages V6a and V6b is large, it is considered that there is an abnormality in the detection circuit DC, for example, the characteristic variation between the differential amplifier circuits A and B is large, or at least one of them is out of order. Specifically, it is determined whether or not the absolute value of the difference between the ratio of the voltage V6a to the voltage V6b and “1” is equal to or greater than the threshold value β. If an affirmative determination is made in step S20, it is determined in step S22 that there is an abnormality in the detection circuit DC.

  In addition, when the process of step S18, S22 is completed, or when negative determination is carried out in the process of step S16, S20, this series of processes is once complete | finished.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) Basically, the detection lines L6a and L6b are respectively provided at both ends of the service plug SP while the detection lines Li for detecting these voltages are shared between the adjacent blocks Bi and B (i-1). Provided. Thereby, it is possible to detect the voltages of the blocks B5 and B6 while removing the influence of the voltage drop of the service plug SP.

  (2) When the current flowing through the service plug SP is equal to or greater than the threshold value α, the resistance value R of the service plug SP is calculated based on the voltage V6a between the detection lines L6a and L7 and the voltage V6b between the detection lines L6b and L7. Thereby, the resistance value R of the service plug SP can be estimated with high accuracy. Further, based on the resistance value R, it can be diagnosed whether the service plug SP is abnormal.

  (3) When the current flowing through the service plug SP is less than the threshold value α, the presence or absence of abnormality of the detection circuit DC is diagnosed based on the voltage V6a between the detection lines L6a and L7 and the voltage V6b between the detection lines L6b and L7. Thereby, the presence or absence of abnormality of the detection circuit DC can be appropriately diagnosed. In particular, the abnormality of the detection circuit DC can be diagnosed by using the detection lines L6a and L6b for detecting the voltages of the blocks B5 and B6 while eliminating the influence of the voltage drop of the service plug SP. The number of parts can be reduced as compared with the case where a separate member is provided for diagnosis.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 4 shows an operation mode of the sampling switches SW1 to SW12 according to the present embodiment. As shown in the figure, in the present embodiment, the process of detecting the voltages of the blocks B0 to B11 is performed by sequentially turning on the adjacent three sampling switches SWi, SW (i + 1), and SW (i + 2). Sampling switches SW6a and SW6b are turned on between this process and the next series of processes. As a result, the voltage between the input line IN1 and the input line IN3 is considered to be about the voltage drop amount of the service plug SP. Therefore, the resistance value R of the service plug SP can be estimated based on this voltage.

  FIG. 5 shows a procedure of an abnormality diagnosis process for the service plug SP based on the switching operation. This process is repeatedly executed by the microcomputer 30 every time the voltage detection process of the blocks B0 to B11 is completed.

  In this series of processes, first, in step S30, it is determined whether or not the current flowing through the assembled battery 10 is equal to or greater than the threshold value α set in the same manner as in the process of step S12 in FIG. If it is determined that the value is greater than or equal to α, the process proceeds to step S32. In step S32, the sampling switches SW6a and SW6b are turned on. In the subsequent step S34, the voltage V across the service plug SP is calculated. This can be calculated as the sum of the voltage Va detected by the differential amplifier circuit A and the voltage Vb detected by the differential amplifier circuit B. Further, in step S36, the resistance value R of the service plug SP is calculated. This is done by dividing the voltage V by the value of the current flowing through the service plug SP when this voltage is detected. Based on the resistance value R thus calculated, in steps S38 and S40, the processing in steps S16 and S18 of FIG. 3 is performed to diagnose the presence or absence of an abnormality in the service plug SP.

  According to this embodiment described above, in addition to the effect (1) of the first embodiment, the following effect can be obtained.

  (4) When the current flowing through the service plug SP is equal to or greater than the threshold value α, the resistance value R of the service plug SP is calculated by turning on the sampling switches SW6a and SW6b. As a result, the resistance value R of the service plug SP can be calculated appropriately, and as a result, the presence or absence of an abnormality in the service plug SP can be diagnosed.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 6 shows an operation mode of the sampling switches SW1 to SW12 according to the present embodiment. As shown in the figure, in this embodiment, a series of processes for detecting the voltages of the blocks B0 to B11 by sequentially turning on the adjacent three sampling switches SWi, SW (i + 1), and SW (i + 2) and the following process During the series of processes, the sampling switches SW5 and SW6b are turned on. As a result, the voltage applied between the input line IN1 and the input line IN2 has a polarity opposite to that in the voltage detection process of the blocks B10 and B11 which is the previous voltage detection process. For this reason, the charging polarity of the flying capacitor 22 should be reversed, and if not reversed, it is considered that the service plug SP is disconnected.

  FIG. 7 shows a procedure of a diagnosis process for determining whether or not the service plug SP is abnormal based on the switching operation. This process is repeatedly executed by the microcomputer 30 at a predetermined cycle, for example.

  In this series of processes, first, in step S50, it is determined whether or not the detection of the voltages V10 and V11 of the blocks B10 and B11 by turning on the sampling switches SW10 to SW12 is completed. If an affirmative determination is made in step S50, the sampling switches SW5 and SW6b are turned on in step S52. In a succeeding step S54, it is determined whether or not the charging polarity of the flying capacitor 22 is reversed. If not reversed, it is determined in step S56 that the service plug SP is abnormal.

  If a negative determination is made in the process of step S50, an affirmative determination is made in the process of step S54, or if the process of step S56 is completed, the series of processes is temporarily terminated.

  According to this embodiment described above, in addition to the effect (1) of the first embodiment, the following effect can be obtained.

  (5) The sampling switches SW5 and SW6b were turned on while the flying capacitor 22 was charged with the opposite polarity to that at the time of voltage detection in the block B5. Thereby, based on the presence or absence of polarity reversal of the flying capacitor 22, it is possible to appropriately diagnose the presence or absence of an abnormality of the service plug SP.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In the third embodiment, the processing for turning on the sampling switches SW5 and SW6b is performed following the processing for detecting the voltages of the blocks B10 and B11 by turning on the sampling switches SW10 to SW12. Absent. For example, as shown in FIG. 8, a process of turning on the sampling switches SW6a and SW7 may be performed following the process of turning on the sampling switches SW10 to SW12 to detect the voltages of the blocks B10 and B11. Even in this case, the presence or absence of disconnection of the service plug SP can be determined in the manner of the third embodiment. Further, the process prior to the switching operation for determining the presence or absence of disconnection is not limited to the process of turning on the sampling switches SW10 to SW12 to detect the voltages of the blocks B10 and B11. In short, prior to detecting the voltage of one or a plurality of blocks by configuring a closed loop circuit including the service plug SP, the service plug SP is not included in advance in such a manner that the charging polarity of the flying capacitor is reversed. The flying capacitor may be charged in a closed loop circuit.

  In the third embodiment, a reset switch may be provided in parallel with the flying capacitors 22 and 24. In this case, after removing the charge from the flying capacitors 22 and 24, the process of turning on the sampling switches SW5 and SW6b is performed to diagnose whether or not the service plug SP is abnormal based on the voltage change. it can.

  In the second embodiment, when the current is less than the threshold value α, the presence or absence of abnormality of the detection circuit DC may be diagnosed based on the difference between the voltages Va and Vb.

  The detection order of the block voltage by operating the multiplexer MPX is not limited to that illustrated in the above embodiments, and may be changed as appropriate. Moreover, you may change suitably also about the connection aspect of the detection lines L0-L12 and the flying capacitors 22 and 23. FIG. However, in the previous third embodiment, it is desirable to adopt a connection mode that enables charging in which both terminals of the flying capacitor are each positive. In other words, it is desirable to adopt a configuration that can take both opposite polarities as the charging polarity of the flying capacitor.

  In the above embodiments, the detection lines L6a and L6b are connected to both ends of the service plug SP, but the present invention is not limited to this. For example, when the assembled battery becomes long, the assembled battery is divided into two parts so that the assembled battery can be folded and placed due to space restrictions when mounting it on a vehicle, and compared with the others to connect them with low resistance. It is conceivable to connect with a conductor (bus bar) having a large cross-sectional area. In this case, it is effective to apply the present invention to suppress a decrease in the detection accuracy of the block voltage due to a voltage drop of the bus bar or to detect an abnormality of the bus bar. At this time, a detection line for connecting to the detection circuit may also be connected to an intermediate portion of the bus bar. According to such a configuration, it is possible to determine which part of the bus bar is abnormal.

  The detection circuit DC is not limited to one having two flying capacitors and two differential amplifier circuits. For example, one flying capacitor and one differential amplifier circuit may be provided. In this case, for example, if the ON operation of the sampling switches SW6a and SW7 and the ON operation of the sampling switches SW6b and SW7 are performed within a predetermined time, it is considered that the change in the voltage of the block B6 during this period can be ignored. Similarly to the first embodiment, it is possible to detect an abnormality in the detection circuit DC and an abnormality in the service plug SP. Furthermore, if three or more flying capacitors and three differential amplifier circuits are provided, the number of blocks capable of detecting the voltage at the same time increases, so that voltage detection can be performed quickly.

  In the first and second embodiments, the detection circuit DC is not limited to the one having the flying capacitors 22 and 24. For example, differential amplification circuits A and B directly connected to the multiplexer MPX, PWM modulation means for PWM modulating the outputs of the differential amplification circuits A and B, and the output of the PWM modulation means are output to the low voltage side (such as the microcomputer 30). Insulating means (such as a photocoupler) may be provided.

  The voltage detection target by the detection circuit DC is not limited to the blocks B0 to B11. For example, a single battery cell may be used. Moreover, it is not restricted to the block grouped for every adjacent battery cell of the same number, Each group grouped for every mutually different number (including 1) may be sufficient.

  -As a battery cell, not only a lithium secondary battery but a nickel hydride battery etc. may be sufficient, for example. Further, the assembled battery is not limited to being mounted on a hybrid vehicle, but may be mounted on an electric vehicle, for example.

1 is a system configuration diagram according to a first embodiment. FIG. The time chart which shows the detection processing aspect of the voltage concerning the embodiment. The flowchart which shows the abnormality detection process procedure concerning the embodiment. The time chart which shows the detection processing aspect of the voltage concerning 2nd Embodiment. The flowchart which shows the abnormality detection process procedure concerning the embodiment. The time chart which shows the detection processing aspect of the voltage concerning 3rd Embodiment. The flowchart which shows the abnormality detection process procedure concerning the embodiment. The time chart which shows the detection process aspect of the voltage concerning the modification of the said 3rd Embodiment.

Explanation of symbols

  10 ... assembled battery, 30 ... microcomputer (one embodiment of estimation means, determination means), SP ... service plug (one embodiment of conduction control means), L1-L12 ... detection line (one embodiment of connection line), DC ... Detection circuit (one embodiment of detection means).

Claims (4)

Detection means for detecting a voltage of the unit battery with respect to a unit battery which is one of a single battery cell and a plurality of adjacent battery cells in an assembled battery configured as a series connection body of a plurality of battery cells. In the assembled battery voltage detecting device,
The specific unit cells adjacent to each other among the unit cells are connected by a heterogeneous connection means having a different structure from the connection means for connecting other unit batteries adjacent to each other,
The connection line for connecting the unit battery and the detection means includes a connection line connected to each of both ends of the heterogeneous connection means,
The heterogeneous connection means includes conduction control means for conducting and blocking between the specific unit cells,
A detected voltage value obtained by connecting both ends of a series connection body of one or more unit cells connected to any terminal of the heterogeneous connection means and the heterogeneous connection means to the detection means, and the one or more A voltage of the assembled battery comprising means for grasping at least one characteristic of the heterogeneous connection means and the detection means based on a detected voltage value obtained by connecting both ends of the unit battery to the detection means Detection device. When the current flowing through the assembled battery is equal to or higher than a threshold value set based on the lower limit value of the amount of current that can detect the resistance value of the heterogeneous connection means with high accuracy, the current is connected to any terminal of the heterogeneous connection means A voltage detection value obtained by connecting both ends of a series connection body of one or more unit cells and the heterogeneous connection means to the detection means, and both ends of the one or more unit cells connected to the detection means. based on the detected value of the voltage by the voltage detection device for a battery pack according to claim 1 Symbol mounting, characterized in that it further comprises estimating means for estimating a resistance value of the heterogeneous connection means. The detection means includes a plurality of circuits for detecting a voltage between a pair of connection lines of the connection lines,
The estimating means connects one end of a series connection body of one or more unit cells connected to any one terminal of the heterogeneous connection means and the heterogeneous connection means to one of the plurality of circuits. performing a voltage detection of the one or more unit cells, the one or more of the one or more unit cells according to the two ends of the unit cells to connect to another one of said plurality of circuits and a voltage detected at the same time The assembled battery voltage detection device according to claim 2 , wherein the resistance value is estimated. The detection means includes a plurality of circuits for detecting a voltage between a pair of connection lines of the connection lines,
When the current flowing through the assembled battery is less than a threshold value set based on the lower limit value of the amount of current that can accurately detect the resistance value of the heterogeneous connection means, it is connected to one of the terminals of the heterogeneous connection means. Voltage detection of the one or more unit cells by connecting both ends of a series connection body of the one or more unit cells and the heterogeneous connection means to one of the plurality of circuits, and the one or more units. Further comprising means for diagnosing the presence or absence of abnormality of the detection means by simultaneously performing voltage detection of the one or more unit batteries by connecting both ends of the battery to another one of the plurality of circuits. The assembled-battery voltage detection apparatus according to claim 1 , wherein:

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