JP7167878B2 - battery monitoring system - Google Patents

Description

The present invention relates to a battery monitoring system applied to an assembled battery including a plurality of unit batteries connected in series.

As a battery monitoring system of this type, there is known one that includes a battery monitoring device having an equalization circuit and a voltage detection unit, as disclosed in Japanese Unexamined Patent Application Publication No. 2002-200012. The voltage detector detects the voltage of each cell. The equalization circuit is provided corresponding to each cell, and includes a switching element provided between the positive terminal and the negative terminal of the corresponding cell. The equalization circuit equalizes the charge amount of each cell by opening and closing the switching element based on the voltage of each cell detected by the voltage detection unit.

JP 2019-14307 A

For example, in an assembled battery used in an electric vehicle or a hybrid vehicle, the number of cells constituting the assembled battery may differ depending on vehicle specifications. In this case, since the number of equalization circuits required for the battery monitoring device is different, it is necessary to redesign the battery monitoring system including the battery monitoring device so as to correspond to the number of equalization circuits. A problem arises that the manufacturing cost of the system increases. For example, there is a demand for a technology capable of standardizing a battery monitoring system even when the number of unit cells, such as cells, constituting an assembled battery is different.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery monitoring system that can be used in common even when the number of unit batteries constituting an assembled battery is different.

A first means for solving the above problems is applied to an assembled battery including a plurality of unit cells connected in series, a monitoring device for monitoring the assembled battery, a control device for controlling the monitoring device, wherein the assembled battery includes a negative terminal side of the unit battery on the lowest potential side, a positive terminal side of the unit battery on the highest potential side, and between the adjacent unit batteries. The monitoring device has n (n≧3) connection points provided, the monitoring device has m (m≧4) detection terminals, and the i-th detection among the m detection terminals Between the connection line connected to the terminal and the connection line connected to the i+1-th detection terminal, a switching element that opens and closes between these connection lines and a voltage detection that detects the voltage between these connection lines. are connected in parallel, m is greater than n, the m detection terminals include unconnected detection terminals that are not connected to the connection point, and the assembled battery includes a plurality of In the specific unit battery among the unit batteries, the unconnected detection terminal is placed between the first detection terminal connected to the connection point on the positive terminal side and the second detection terminal connected to the connection point on the negative terminal side. is connected to the monitoring device so as to intervene, the control device includes an equalization determination unit that determines whether or not to perform equalization processing for each of the unit batteries; one of the plurality of switching elements connected between a connection line connected to the first detection terminal and a connection line connected to the second detection terminal when it is determined to perform the conversion process Detection in which the voltage of the specific unit battery is detected using the voltage detection section connected in parallel to the specific switching element in a state in which one specific switching element is turned off and the switching elements other than the specific switching element are turned on. and a processing unit.

In the battery monitoring system, the number (m) of detection terminals in the monitoring device may be greater than the number (n) of connection points in the assembled battery depending on the number of unit batteries that constitute the assembled battery. When the number of detection terminals is greater than the number of connection points, the first detection terminal connected to the connection point on the positive terminal side and the connection point on the negative terminal side are connected to at least one unit battery among the plurality of unit batteries. An unconnected detection terminal that is not connected to the connection point may be interposed between the second detection terminal that is connected to the connection point.

In the monitoring device, since the switching element and the voltage detection section are connected in parallel between the connection lines connected to the detection terminals, the voltage of the specific unit battery cannot be detected if there is an unconnected detection terminal. Therefore, when an unconnected detection terminal is interposed, it is necessary to connect the unconnected detection terminal to the first detection terminal or the second detection terminal in order to detect the voltage of the specific unit battery. In order to connect the unconnected detection terminal to the first detection terminal or the second detection terminal, for example, to connect a resistance member between these terminals, a monitoring device is required to provide a space for arranging the resistance member. The included battery monitoring system must be redesigned, and the addition of resistive elements increases the manufacturing cost of the battery monitoring system.

In this means, a switching element provided in the monitoring device is used to connect the unconnected detection terminal to the first detection terminal or the second detection terminal. Therefore, even if specific unit batteries are provided according to the number of unit batteries that constitute the assembled battery, the voltage of the specific unit batteries can be detected without redesigning the battery monitoring system. Therefore, the battery monitoring system can be shared even when the number of unit batteries constituting the assembled battery is different.

In a second means, the control device includes a discharge determination unit that determines whether or not to equalize discharge the specific unit battery based on the voltage of the specific unit battery detected by the detection processing unit; the plurality of switching elements connected between the connection line connected to the first detection terminal and the connection line connected to the second detection terminal when it is determined that the specific unit battery is to be equalized discharge and an equalization unit that performs equalization discharge in a state where all are turned on.

In this means, in the equalization process, any one of the plurality of switching elements connected between the connection line connected to the first detection terminal and the connection line connected to the second detection terminal is selected. The voltage of the specific unit battery is detected with the element turned off and the switching elements other than the specific switching element turned on. When the specific unit battery is to be equalized and discharged, the plurality of switching elements are all turned on to perform the equalized discharge. Therefore, even when the specific unit batteries are provided according to the number of unit batteries constituting the assembled battery, the connection wire connected to the first detection terminal and the connection wire connected to the second detection terminal are connected to each other. By switching the states of a plurality of switching elements, it is possible to equalize and discharge a specific unit battery without redesigning the battery monitoring system.

In the third means, the first detection terminal is connected to a connection point on the negative terminal side of the unit battery with the lowest potential side, and the n-th detection terminal is connected to the connection point of the unit battery with the highest potential side. It is connected to a connection point on the positive terminal side, and power is supplied to the monitoring device from a connection line connected to the first detection terminal and a connection line connected to the nth detection terminal.

In a configuration in which the number of detection terminals is greater than the number of connection points, the first detection terminal is connected to the connection point on the negative terminal side of the lowest potential side unit battery to supply power to the monitoring device, and n The second detection terminal is connected to the connection point on the positive terminal side of the unit battery on the highest potential side. Therefore, at least one unit battery among the plurality of unit batteries becomes a specific unit battery in which the unconnected detection terminal is interposed between the first detection terminal and the second detection terminal. With this means, even if a specific unit battery is provided, the voltage of the specific unit battery can be detected without redesigning the battery monitoring system, and the battery monitoring system can be shared.

In the fourth means, in the monitoring device, a capacitor having a predetermined capacity is provided between the connection line connected to the i-th detection terminal and the connection line connected to the (i+1)-th detection terminal and the switching element. The equalization determination unit is connected in parallel to the voltage detection unit, and the equalization determination unit determines whether or not to perform the equalization process when a start switch of the battery monitoring system is in an off state. The control device includes a plurality of switching elements connected between a connection line connected to the first detection terminal and a connection line connected to the second detection terminal when the activation switch is in an ON state. and a state control unit that always turns on the switching elements other than the specific switching element.

When the activation switch of the battery monitoring system is in the ON state, noise may occur at the disconnection detection terminal. In the monitoring device, a capacitor is connected between the connection lines connected to each connection terminal, and this capacitor suppresses noise generated at the unconnected detection terminal from entering the first detection terminal and the second detection terminal. be done. However, since a plurality of capacitors are connected in series between the first detection terminal and the second detection terminal, the combined capacitance of the capacitors between the first detection terminal and the second detection terminal is a predetermined capacitance. lower than Therefore, noise generated between the positive terminal and the negative terminal of the specific unit battery cannot be removed by using a plurality of capacitors connected in series between the first detection terminal and the second detection terminal.

In this means, when the activation switch is in the ON state, among the plurality of switching elements connected between the connection line connected to the first detection terminal and the connection line connected to the second detection terminal, Switching elements other than the specific switching element are always turned on. As a result, the capacity of the capacitor between the first detection terminal and the second detection terminal can be set to a predetermined capacity (that is, a single capacitor capacity), and the capacity of the capacitor between the positive terminal and the negative terminal of the specific unit battery can be set to a predetermined capacity. The generated noise can be preferably removed.

In the fifth means, the control device includes an acquisition unit that acquires a physical quantity expressing the charge amount of each unit battery, and an identification unit that identifies the unconnected detection terminal based on the physical quantity.

Charging and discharging of the unit battery causes the voltage of the unit battery to fluctuate and the temperature to rise. Therefore, the voltage and temperature of the unit battery can be said to be physical quantities that express the charge amount of the unit battery. For example, in the case of obtaining the inter-terminal voltage between the detection terminals using the voltage detection unit as this physical quantity, if the voltage of the unit battery cannot be obtained, of the pair of detection terminals connected to the voltage detection unit, At least one can be identified as an unconnected detection terminal. Further, if the temperature distribution in the assembled battery is obtained as this physical quantity using a temperature sensor, the position of each unit battery can be specified, and thus the unconnected detection terminal can be specified. If the unconnected detection terminal can be identified, the specific unit battery can be identified and the voltage of the specific unit battery can be detected.

The whole block diagram of a battery monitoring system. The figure which shows the battery monitoring apparatus which concerns on 1st Embodiment. FIG. 3 shows a redesigned battery monitor. 4 is a flowchart of off control processing according to the first embodiment; 4 is a flowchart of ON control processing; FIG. 4 is a diagram showing states of switching elements during voltage detection and during equalization discharge; The figure which shows the battery monitoring apparatus which concerns on 2nd Embodiment. The figure which shows the battery monitoring apparatus which concerns on 3rd Embodiment. 10 is a flowchart of off control processing according to the third embodiment;

<First embodiment>
A first embodiment of a battery monitoring system according to the present invention will be described below with reference to the drawings. A battery monitoring system 100 of the present embodiment is mounted on a vehicle.

As shown in FIG. 1 , the battery monitoring system 100 includes a rotating electrical machine 10 and an inverter 20 . In this embodiment, the rotating electrical machine 10 includes a three-phase winding 11 that is star-connected. A rotor of the rotating electric machine 10 is connected to drive wheels of the vehicle so as to allow power transmission. The rotary electric machine 10 is, for example, a synchronous machine.

The rotating electric machine 10 is connected to a DC power supply 21 via an inverter 20 . In this embodiment, the DC power supply 21 is a storage battery. A smoothing capacitor 22 is provided between the DC power supply 21 and the inverter 20 .

The inverter 20 includes a series connection body of an upper arm switch SWH and a lower arm switch SWL for each of the U, V, and W phases. In this embodiment, IGBTs are used as the switches SWH and SWL. The upper arm switch SWH has an antiparallel-connected upper arm diode DH, and the lower arm switch SWL has an antiparallel-connected lower arm diode DL.

In each phase, a first end of winding 11 of rotating electric machine 10 is connected to a connection point between the source of upper arm switch SWH and the drain of lower arm switch SWL. A second end of each phase winding 11 is connected at a neutral point.

The battery monitoring system 100 also includes a phase current detector 23 , a power supply voltage detector 24 , a controller 30 , and a battery monitor 40 . The phase current detection unit 23 detects at least two phase currents among the phase currents flowing in the rotating electric machine 10 . The power supply voltage detection unit 24 detects the terminal voltage of the smoothing capacitor 22 as the power supply voltage VHr. Detected values of the detectors 23 and 24 are input to the control device 30 .

Control device 30 controls inverter 20 to control the control amount of rotating electric machine 10 to the command value. The controlled variable is, for example, torque. In order to alternately turn on the upper and lower arm switches SWH and SWL with a dead time in between, the control device 30 outputs upper and lower arm drive signals SGH and SGL corresponding to the upper and lower arm switches SWH and SWL. , and lower arm switches SWH and SWL. Battery monitoring device 40 monitors DC power supply 21 under the control of control device 30 .

An IG switch 31, which is a start switch of the vehicle, is connected to the control device 30, and the control device 30 monitors the ON/OFF state of the IG switch 31. As shown in FIG. Note that, in the present embodiment, the IG switch 31 corresponds to the "start switch".

FIG. 2 shows a configuration diagram of the DC power supply 21 and the battery monitoring device 40 in this embodiment. The DC power supply 21 is an assembled battery configured by connecting a plurality of cells C in series. In addition, each cell C of the present embodiment is configured by a lithium ion secondary battery. In this embodiment, the cell C corresponds to a "unit battery".

In this embodiment, the DC power supply 21 has nine cells C1 to C9. Further, the DC power supply 21 is provided with ten connection points X1 to X10. The connection points X1 to X10 are provided on the negative terminal side of the cell C1 on the lowest potential side, on the positive terminal side of the cell C9 on the highest potential side, and between adjacent cells C1 to C9, respectively. Therefore, the number of connection points X1 to X10 is one more than the number of cells C1 to C9. When n is an integer from 1 to 9, the negative terminal of the nth cell Cn is connected to the nth connection point Xn, and the positive terminal of the nth cell Cn is connected to the n+1th connection point Xn+1. there is

The battery monitoring device 40 includes a monitoring IC 41 provided corresponding to the DC power supply 21 and a protection circuit 42 provided on the input side of the monitoring IC 41 . The monitoring IC 41 detects various monitoring information (voltage, temperature, etc.) and monitors the states of the cells C1 to C9, and has 13 detection terminals Y1 to Y13.

Battery monitoring connection lines L1 to L13 are connected to the detection terminals Y1 to Y13, respectively, and the monitoring IC 41 is connected to the connection lines L1 to L13. The monitoring IC 41 detects the voltage of each cell C1-C9 based on the current input through each connection line L1-L13.

The protection circuit 42 is provided on the connection lines L1 to L13, and includes a fuse 50, a chip bead 51, a Zener diode 52, and a capacitor 53. A fuse 50 and a chip bead 51 are provided on each connection line L1 to L13. The fuse 50 and the chip bead 51 are provided in this order between the detection terminals Y1 to Y13 and the monitoring IC 41 on each of the connection lines L1 to L13. The chip bead 51 is an inductor element configured to have high inductance on the high frequency side. Therefore, the chip bead 51 removes noise from the current input through the connection lines L1 to L13.

Zener diode 52 is connected between adjacent connection lines L1 to L13. Specifically, the Zener diode 52 is connected between the chip bead 51 and the monitoring IC 41 on each of the connection lines L1 to L13. The Zener diode 52 is connected between the i-th connection line Li and the i+1-th connection line Li+1, where i is an integer from 1 to 12, and the current flows from the i-th connection line Li to the i+1-th connection line Li+1. It is provided so that the direction in which the current flows is the forward direction. For example, when the i-th connection line Li is connected to the connection point X on the negative terminal side of the cell C, and the i+1-th connection line Li+1 is connected to the connection point X on the positive terminal side of the cell C, overcharging, etc. It is assumed that a voltage higher than the reference voltage is generated in this cell C by . In this case, the charge stored in the cell C flows through the Zener diode 52 from the i+1-th connection line Li+1 on the high voltage side toward the i-th connection line Li on the low voltage side, and the voltage of the cell C reaches a predetermined level. Limited.

The capacitor 53 is connected between adjacent connection lines L1 to L13. Specifically, the capacitor 53 is connected between the Zener diode 52 and the monitoring IC 41 on each of the connection lines L1 to L13. The capacitance of the capacitor 53 is set to a predetermined value, and the provision of the capacitor 53 removes noise (high frequency components) generated between the adjacent connection lines L1 to L13.

The monitoring IC 41 has a switching element 43 and a voltage detector 45 . The switching element 43 is connected between adjacent connection lines L1 to L13 and opens and closes between these connection lines L1 to L13. The switching element 43 is a switch corresponding to high voltage and low current, and uses, for example, an N-channel MOSFET. A parasitic diode 44 is connected in parallel with the switching element 43 .

The voltage detection unit 45 is connected between adjacent connection lines L1 to L13. That is, the Zener diode 52, the capacitor 53, the switching element 43, and the voltage detector 45 are connected in parallel between the i-th connection line Li and the i+1-th connection line Li+1. The voltage detection unit 45 detects voltages between adjacent connection lines L1 to L13. Therefore, when the adjacent connection lines L1 to L13 are connected to the connection point X on the negative terminal side and the positive terminal side of a certain cell C, the voltage of that cell C is detected.

The monitoring IC 41 operates by being supplied with power from the DC power supply 21 . Specifically, the first detection terminal Y1 is connected to the first connection point X1 on the negative terminal side of the first cell C1 on the lowest voltage side of the DC power supply 21 . The thirteenth detection terminal Y13 is connected to the tenth connection point X10 on the positive terminal side of the ninth cell C9 on the highest voltage side of the DC power supply 21 . The monitoring IC 41 is connected to the first connection line L1 connected to the first detection terminal Y1 via the low-voltage side voltage line LD, and is connected to the thirteenth detection terminal Y13 via the high-voltage side voltage line LU. 13 connection line L13, and electric power is supplied from the first and thirteenth connection lines L1 and L13. Note that the high-voltage side voltage line LU and the low-voltage side voltage line LD are omitted from FIG. 3 onward.

Other connection points X2 to X9 of the DC power supply 21 are also connected to one detection terminal Y2 to Y12, respectively. Specifically, when n is an integer from 2 to 8 and m is an integer from 2 to 12, the nth connection point Xn on the low voltage side is higher than the n+1th connection point Xn+1 on the high voltage side. , that is, is connected to the detection terminal Ym where m is small.

In this embodiment, the connection points X2-X9 are connected to the detection terminals Y2-Y9. On the other hand, the detection terminals Y10-Y12 are not connected to the connection points X1-X10. In the DC power supply 21, in the ninth cell C9 among the cells C1 to C9, the thirteenth detection terminal Y13 connected to the tenth connection point X10 on the positive terminal side and the ninth connection point X9 on the negative terminal side are connected. The unconnected detection terminals Y10 to Y12, which are not connected to the connection points X1 to X10, are connected to the battery monitoring device 40 such that they are interposed between the ninth detection terminal Y9 and the ninth detection terminal Y9. In this embodiment, the ninth cell C9 corresponds to the "specific unit battery", the thirteenth detection terminal Y13 corresponds to the "first detection terminal", and the ninth detection terminal Y9 corresponds to the "second detection terminal". Equivalent to.

By the way, in the DC power supply 21, the number of C1 to C9 constituting the DC power supply 21 may differ depending on the specifications of the vehicle, and the number of the switching elements 43 and the like required for the monitoring IC 41 may differ. In this case, if the battery monitoring device 40 is configured using the common monitoring IC 41 regardless of the number of C1 to C9 constituting the DC power supply 21, the number of the detection terminals Y1 to Y13 in the battery monitoring device 40 is The number may be greater than the number of connection points X1 to X10 in the DC power supply 21 . If the number of detection terminals Y1-Y13 is greater than the number of connection points X1-X10, unconnected detection terminals Y10-Y12 intervene.

In the monitor IC 41, since the voltage detection unit 45 detects the voltage between the adjacent connection lines L1 to L13, the voltage of the ninth cell C9 cannot be detected when the unconnected detection terminals Y10 to Y12 intervene. In order to detect the voltage of the ninth cell C9, it is necessary to connect the unconnected detection terminals Y10 to Y12 to the ninth detection terminal Y9 or the thirteenth detection terminal Y13.

If the protection circuit 42 is used to connect the unconnected detection terminals Y10 to Y12 to the ninth detection terminal Y9 or the thirteenth detection terminal Y13, the protection circuit 42 needs to be redesigned. Specifically, as shown in FIG. 3, the capacitor 53 connected between the connection lines L9 to L12 is removed, and a resistor 54 having a resistance value of zero Ω is connected to the portion where the capacitor 53 is removed. . In addition, the Zener diode 52 connected between the connection lines L9 to L13 is removed, and the Zener diode 52 is connected between the ninth connection line L9 and the thirteenth connection line L13 so as not to be connected to the connection lines L10 to L12. Connecting. Accordingly, the voltage of the ninth cell C9 can be detected using the voltage detection section 45 connected between the twelfth connection line L12 and the thirteenth connection line L13. However, redesigning the battery monitoring system 100 including the protection circuit 42 and adding the resistor 54 increase the manufacturing cost of the battery monitoring system 100 .

The control device 30 of this embodiment uses the switching element 43 provided in the monitoring IC 41 to perform control processing to connect the unconnected detection terminals Y10 to Y12 to the ninth detection terminal Y9 or the thirteenth detection terminal Y13. Therefore, even if the disconnection detection terminals Y10 to Y12 are interposed, the voltage of the ninth cell C9 can be detected without redesigning the battery monitoring system 100 including the protection circuit . Therefore, the battery monitoring device 40 can be configured using the common monitoring IC 41 regardless of the number of cells C1 to C9 constituting the DC power supply 21, and the number of cells C1 to C9 constituting the DC power supply 21 can be changed. Even in such a case, the battery monitoring system 100 can be shared.

4 and 5 show flowcharts of the control processing of this embodiment. FIG. 4 shows an off control process performed by control device 30 when IG switch 31 is in the off state. Specifically, when the IG switch 31 is switched to the OFF state, the control device 30 repeatedly performs the OFF control process every predetermined period.

When the off control process is started, first, in step S10, it is determined whether or not the equalization process is to be performed. The equalization process is a process of equalizing and discharging some cells C having a larger amount of charge than other cells C so as to equalize the voltages of the cells C1 to C9. As a result, it is possible to uniform the voltages of the cells C and prevent some of the cells C1 to C9 from being overcharged. The equalization process is performed when a predetermined equalization condition is satisfied, and the equalization condition is, for example, that the voltage difference of each cell C becomes equal to or greater than a threshold. In addition, in this embodiment, the process of step S10 corresponds to the "equalization determination unit".

If a negative determination is made in step S10, the off control process ends. On the other hand, if an affirmative determination is made in step S10, in step S12, the plurality of switching elements 43 connected to the unconnected detection terminals Y10 to Y12, that is, the plurality of switching elements 43 connected between the ninth connection point X9 and the thirteenth detection terminal Y13. of the switching elements 43, one specific switching element (specific SW) 43A is turned off, and switching elements other than the specific switching element (hereinafter referred to as non-specific switching elements (non-specific SW)) 43B are turned on. In the subsequent step S14, voltages of the cells C1 to C9 are detected. It should be noted that in the present embodiment, the process of step S14 corresponds to the "detection processing unit".

6A and 6B show a plurality of switching elements 43 and a plurality of voltage detectors 45 connected between the ninth connection point X9 and the thirteenth detection terminal Y13. Among these, FIG. 6A shows a state in which the specific switching element 43A among the plurality of switching elements 43 is turned off and the non-specific switching element 43B is turned on. In this embodiment, the specific switching element 43A is the switching element 43 connected between the 12th connection point X12 and the 13th detection terminal Y13, and the non-specific switching element 43B is the 9th connection point X9 and the 12th detection terminal Y13. It is the switching element 43 connected between the detection terminal Y12. 6A and 6B, the specific switching element 43A and the non-specific switching element 43B are shown in a simplified manner for the sake of explanation.

As shown in FIG. 6A, when the specific switching element 43A is turned off and the non-specific switching element 43B is turned on, the voltage of the ninth cell C9 is detected via the voltage detection unit 45 connected in parallel to the specific switching element 43A. A positive terminal and a negative terminal of are connected. Therefore, in step S14, the voltage of the ninth cell C9 can be detected using the voltage detector 45. FIG.

In the following step S16, diagnosis (failure diagnosis) processing is performed. In the diagnostic process, disconnection or the like of the connection lines L1 to L13 is diagnosed. Therefore, the connection lines L10 to L12 connected to the unconnected detection terminals Y10 to Y12 are erroneously diagnosed as being disconnected even if the connection lines L10 to L12 are not disconnected. In the present embodiment, diagnostic processing is performed with the non-specific switching element 43B turned on in step S12. Therefore, erroneous diagnosis that disconnection has occurred in the connection lines L10 to L12 is suppressed. When the diagnostic process is completed, the non-specific switching element 43B is turned off in step S18.

In subsequent step S20, it is determined whether or not the ninth cell C9 is to be equalized discharge based on the voltage detected in step S14. If a negative determination is made in step S20, the off control process ends. In addition, in this embodiment, the process of step S20 corresponds to a "discharge determination part."

On the other hand, if an affirmative determination is made in step S20, all of the plurality of switching elements 43 connected between the ninth connection point X9 and the thirteenth detection terminal Y13, that is, the specific switching element 43A and the non-specific switching element 43B are detected in step S22. and both are turned on. As a result, all of the switching elements 43 connected between the ninth connection point X9 and the thirteenth detection terminal Y13 are turned on. It should be noted that in the present embodiment, the process of step S22 corresponds to the "equalization section".

FIG. 6B shows a state in which both the specific switching element 43A and the non-specific switching element 43B are turned on. As shown in FIG. 6B, when both the specific switching element 43A and the non-specific switching element 43B are turned on, the positive terminal and the negative terminal of the ninth cell C9 are connected via these switching elements 43. Connected. Therefore, the ninth cell C9 is equalized and discharged.

In subsequent step S24, it is determined whether or not the equalizing discharge has been completed. If a negative determination is made in step S24, the process of step S24 is repeated. On the other hand, if an affirmative determination is made in step S24, in step S26, the specific switching element 43A and the non-specific switching element 43B are turned off, and the off control process ends.

FIG. 5 shows an ON control process performed by control device 30 when IG switch 31 is in the ON state. Specifically, when the IG switch 31 is switched to the ON state, the control device 30 repeatedly performs the ON control process at predetermined intervals.

When the off control process is started, first, in step S30, the non-specific switching element 43B is turned on (see FIG. 8A). If the non-specific switching element 43B has already been turned on in the previously performed off control process, that state is maintained. Therefore, when the IG switch 31 is on, the non-specific switching element 43B is always on. In addition, in this embodiment, the process of step S30 corresponds to a "state control part."

In step S32, it is determined whether the IG switch 31 has been turned off. If a negative determination is made in step S32, the off control process ends. On the other hand, if an affirmative determination is made in step S32, diagnostic processing is performed in step S34. In subsequent step S36, the non-specific switching element 43B is turned off, and the off control process ends.

According to this embodiment detailed above, the following effects can be obtained.

・In the battery monitoring system 100, the number of detection terminals Y1 to Y13 in the battery monitoring device 40 is greater than the number of connection points X1 to X10 in the DC power supply 21 according to the number of cells C1 to C9 constituting the DC power supply 21. can be. When the number of the detection terminals Y1 to Y13 is larger than the number of the connection points X1 to X10, the unconnected detection terminals Y10 to Y12 are interposed in the ninth cell C9, which is at least one of the plurality of cells C1 to C9. I have something to do. Specifically, between the thirteenth detection terminal Y13 connected to the tenth connection point X10 on the positive terminal side of the ninth cell C9 and the ninth detection terminal Y9 connected to the ninth connection point X9 on the negative terminal side , there may be unconnected detection terminals Y10 to Y12 that are not connected to the connection points X1 to X10.

In the battery monitoring device 40, the voltage detection unit 45 is connected between the connection lines L1 to L13 connected to the detection terminals Y1 to Y13. The voltage of C9 cannot be detected. Therefore, when the unconnected detection terminals Y10 to Y12 are interposed, the unconnected detection terminals Y10 to Y12 are connected to the ninth detection terminal Y9 or the thirteenth detection terminal Y13 in order to detect the voltage of the ninth cell C9. There is a need. In order to connect the unconnected detection terminals Y10 to Y12 to the ninth detection terminal Y9 or the thirteenth detection terminal Y13, it is conceivable to connect a resistor 54 between these terminals in the protection circuit 42, for example. In this case, it is necessary to redesign the battery monitoring system 100 including the battery monitoring device 40 by, for example, removing the capacitor 53 in order to provide a space for arranging the resistor 54. Manufacturing costs increase.

In this embodiment, the switching element 43 provided in the battery monitoring device 40 is used to connect the unconnected detection terminals Y10 to Y12 to the ninth detection terminal Y9 or the thirteenth detection terminal Y13. Therefore, even if cells C having disconnection detection terminals Y10 to Y12 are provided according to the number of cells C1 to C9 constituting the DC power supply 21, the cell C can be used without redesigning the battery monitoring system 100. Voltage can be detected. Therefore, even if the number of cells C1 to C9 constituting the DC power supply 21 is different, the battery monitoring system 100 can be shared.

Especially in this embodiment, in order to supply power to the battery monitoring device 40, the first detection terminal Y1 among the detection terminals Y1 to Y13 is connected to the first connection point X1 on the lowest potential side, and the thirteenth detection is performed. The terminal Y13 is connected to the tenth connection point X10 on the highest potential side. Therefore, in at least one cell C (the ninth cell C9 in this embodiment) among the plurality of cells C1 to C9, the thirteenth detection terminal Y13 connected to the positive terminal side and the ninth detection terminal Y13 connected to the negative terminal side Disconnected detection terminals Y10 to Y12 that are not connected to the connection points X1 to X10 are interposed between the terminal Y9 and the terminal Y9. In this embodiment, even when the disconnection detection terminals Y10 to Y12 are interposed, the switching element 43 provided in the battery monitoring device 40 is used to switch the disconnection detection terminals Y10 to Y12 to the ninth detection terminal Y9 or the thirteenth detection terminal. Connect to terminal Y13. Therefore, the voltage of the ninth cell C9 can be detected without redesigning the battery monitoring system 100, and the battery monitoring system 100 can be shared.

In the present embodiment, in the equalization process, a plurality of Among the switching elements 43, the voltage of the ninth cell C9 is detected with the specific switching element 43A turned off and the non-specific switching element 43B turned on. When the ninth cell C9 is to be subjected to equalization discharge, the plurality of switching elements, that is, both the specific switching element 43A and the non-specific switching element 43B are switched to the ON state, and the equalization discharge is performed. Therefore, even if the cells C interposed with the unconnected detection terminals Y10 to Y12 are provided according to the number of the cells C1 to C9 constituting the DC power supply 21, the states of the specific switching element 43A and the non-specific switching element 43B are switched. Thus, equalization discharge can be performed without redesigning the battery monitoring system 100 .

- When the IG switch 31 of the battery monitoring system 100 is in the ON state, noise may occur at the disconnection detection terminals Y10 to Y12. In the battery monitoring device 40, a capacitor 53 is connected between the connection lines L1 to L13 connected to the detection terminals Y1 to Y13. 9 detection terminal Y9 and the 13th detection terminal Y13 are prevented from being mixed. However, since a plurality of capacitors 53 are connected in series between the ninth detection terminal Y9 and the thirteenth detection terminal Y13, the capacity of the capacitor 53 between the ninth detection terminal Y9 and the thirteenth detection terminal Y13 is The combined capacity is lower than the prescribed capacity. Therefore, noise generated between the positive terminal and the negative terminal of the ninth cell C9 cannot be removed using the plurality of capacitors 53 connected in series between the ninth detection terminal Y9 and the thirteenth detection terminal Y13. .

In the present embodiment, when the IG switch 31 is in the ON state, the 9th connection line L9 connected to the 9th detection terminal Y9 and the 13th connection line L13 connected to the 13th detection terminal Y13 are connected. Among the plurality of connected switching elements 43, the non-specific switching element 43B is always turned on. As a result, the capacity of the capacitor 53 between the ninth detection terminal Y9 and the thirteenth detection terminal Y13 can be set to a predetermined capacity (that is, the capacity of a single capacitor 53), and the positive terminal of the ninth cell C9 and Noise generated between the negative terminal and the negative terminal can be preferably removed.

(Second embodiment)
The second embodiment will be described below with reference to FIG. 7, focusing on differences from the first embodiment. In FIG. 7, the same reference numerals are given to the same components as those shown in FIG. 3, and the description thereof will be omitted.

In this embodiment, the configuration of the protection circuit 42 is different from that of the first embodiment. The protection circuit 42 of this embodiment further includes a resistor 55 and a filter circuit 56 . A resistor 55 is provided for each of the connection lines L1 to L13. Specifically, the resistor 55 is connected between the capacitor 53 and the monitoring IC 41 on each of the connection lines L1 to L13. By providing the resistors 55 in the respective connection lines L1 to L13, the inrush current flowing through the monitoring IC 41 is suppressed.

In this embodiment, the voltage detection unit 45 is connected to the connection lines L1 to L13 adjacent to the low voltage side via the detection line 46. FIG. Specifically, one end of the detection line 46 is connected to the voltage detection section 45, and the other end of the detection line 46 is connected between the capacitor 53 and the resistor 55 in the connection lines L1 to L13 adjacent to the low voltage side. It is

Each detection line 46 is provided with a filter circuit 56 . The filter circuit 56 is provided between each detection line 46 and the connection lines L1 to L13 on the high voltage side. The filter circuit 56 is a low-pass filter composed of a filter resistor 57 and a filter capacitor 58 . A filter resistor 57 is provided for each detection line 46 . One end of the filter capacitor 58 is connected in each detection line 46 between the filter resistor 57 and the connecting lines L1 to L13 adjacent to the low voltage side. The other end of the filter capacitor 58 is connected between the resistor 55 and the monitoring IC 41 on the high voltage side connection lines L1 to L13.

According to this embodiment detailed above, the following effects can be obtained.

In the present embodiment, the resistors 55 are provided in the connection lines L1 to L13, thereby suppressing rush current from flowing through the monitoring IC 41. FIG. On the other hand, by providing the resistor 55 , the resistor 55 is provided in the voltage measurement path of the voltage detection section 45 . In this case, if the detection line 46 is not provided in the protection circuit 42 and the voltage measurement path of the voltage detection unit 45 is the same as the discharge path of the switching element 43, two resistors 55 are arranged in this voltage measurement path. , the voltage detection accuracy of the voltage detection unit 45 is lowered.

In this embodiment, the detection line 46 is provided in the protection circuit 42, the voltage measurement path of the voltage detection unit 45 and the discharge path of the switching element 43 are differentiated, and one resistor 55 is provided in the voltage measurement path of the voltage detection unit 45. only be placed. Therefore, it is possible to suppress a decrease in voltage detection accuracy of the voltage detection unit 45 while suppressing rush current from flowing through the monitoring IC 41 . Furthermore, by providing the filter circuit 56, the voltage detection accuracy of the voltage detection unit 45 can be improved.

(Third embodiment)
The third embodiment will be described below with reference to FIG. 8, focusing on differences from the first embodiment. In FIG. 8, the same reference numerals are assigned to the same components as those shown in FIG. 3, and the description thereof will be omitted.

This embodiment differs from the first embodiment in that the battery monitoring device 40 includes a temperature sensor 47 . Battery monitoring device 40 includes a plurality of temperature sensors 47 . These temperature sensors 47 are arranged at predetermined intervals in the DC power supply 21 and detect the temperature distribution in the DC power supply 21 .

Since the temperature of each of the cells C1 to C9 of the DC power supply 21 increases due to charging and discharging, the temperature sensor 47 is used to detect the temperature distribution to identify the positions of the cells C1 to C9. The unconnected detection terminals Y10 to Y12 are specified using the positions of the cells C1 to C9. For example, if the cells C1 to C8 among the cells C1 to C9 are provided at positions corresponding to the detection terminals Y1 to Y9 in the battery monitoring device 40, the unconnected detection terminals Y10 to Y12 are not connected to the detection terminals Y1 to Y9. It is specified that it is included in the detection terminals Y10 to Y13. Since the thirteenth detection terminal Y13 is connected to the tenth connection point X10 in order to supply power to the battery monitoring device 40, the unconnected detection terminals Y10 to Y12 are specified.

The unconnected detection terminals Y10 to Y12 can also be specified using the voltage detection section 45. FIG. Specifically, when the corresponding switching element 43 is turned off, the voltage detection unit 45 is used to detect the inter-terminal voltage, which is the voltage between the adjacent detection terminals Y1 to Y13. When the detected inter-terminal voltage is within the voltage range of each cell C1-C9, it is specified that the connection lines L1-L13 connected to the voltage detection unit 45 are not the unconnected detection terminals Y10-Y12. be done. On the other hand, when the detected voltage exceeds the voltage of the use range of each cell C1 to C9, at least one of the pair of detection terminals Y1 to Y13 connected to the voltage detection unit 45 detects disconnection detection. Terminals Y10 to Y12 are specified.

Physical quantities such as temperature and voltage of each of the cells C1 to C9 fluctuate due to charging and discharging. Therefore, these physical quantities can be said to be physical quantities that express the amount of charge in each of the cells C1 to C9. The control device 30 acquires these physical quantities representing the amount of charge, and performs off control processing including processing for identifying the unconnected detection terminals Y10 to Y12.

FIG. 9 shows a flowchart of the off control process of this embodiment. In FIG. 9, for the sake of convenience, the same step numbers are assigned to the same processes as those shown in FIG. 4, and the description thereof is omitted.

When the off control process is started, first, in step S40, it is determined whether the unconnected detection terminals (unconnected T) Y10 to Y12 are specified. If an affirmative determination is made in step S40, the process proceeds to step S10.

On the other hand, if a negative determination is made in step S40, the temperature distribution in the DC power supply 21 is acquired using the temperature sensor 47 in step S42. In the following step S44, the voltage between terminals is obtained using the voltage detection unit 45. FIG. It should be noted that in the present embodiment, the processing of steps S42 and S44 corresponds to the "acquisition unit".

In the subsequent step S46, the unconnected detection terminals Y10 to Y12 are identified based on the temperature distribution obtained in step S42 and the inter-terminal voltage obtained in step S44. Specifically, the control device 30 tentatively identifies the unconnected detection terminals Y10 to Y12 based on the temperature distribution, and tentatively identifies the unconnected detection terminals Y10 to Y12 based on the inter-terminal voltage. If the unconnected detection terminals Y10 to Y12 tentatively identified based on the temperature distribution are equal to the unconnected detection terminals Y10 to Y12 tentatively identified based on the inter-terminal voltage, the control device 30 detects the unconnected detection terminals. Specify Y10 to Y12. It should be noted that in the present embodiment, the process of step S46 corresponds to the "specification unit".

According to this embodiment detailed above, the following effects can be obtained.

・By charging and discharging the cells C1 to C9, the voltages of the cells C1 to C9 fluctuate and the temperature rises. Therefore, the voltage and temperature of each of the cells C1 to C9 can be said to be physical quantities that express the amount of charge in each of the cells C1 to C9. For example, as this physical quantity, when the voltage between the detection terminals is obtained using the voltage detection unit 45, if the voltages of the cells C1 to C9 cannot be obtained, the pair of detection signals connected to the voltage detection unit 45 At least one of the terminals Y1 to Y13 can be identified as the disconnection detection terminals Y10 to Y12. Also, if the temperature distribution in the DC power supply 21 is obtained as this physical quantity using the temperature sensor 47, the positions of the cells C1 to C9 can be identified, thereby identifying the unconnected detection terminals Y10 to Y12.

If the unconnected detection terminals Y10 to Y12 can be identified, the unconnected detection terminals Y10 to Y12 are interposed between the thirteenth detection terminal Y13 connected to the positive terminal and the ninth detection terminal Y9 connected to the negative terminal. A ninth cell C9 can be identified. By individually controlling the specific switching element 43A and the non-specific switching element 43B, the voltage of the ninth cell C9 can be detected and equalized discharge can be performed.

(Other embodiments)
The present invention is not limited to the description of the above embodiments, and may be implemented as follows.

- In the above embodiment, an example in which the DC power supply 21 includes nine cells C1 to C9 is shown, but the present invention is not limited to this. may comprise a cell C of

- Although each cell C showed the example which is a lithium ion secondary battery in the said embodiment, it is not restricted to this, A lead storage battery and a nickel metal hydride storage battery may be used.

- In the above-described embodiment, an example in which the unit battery is composed of one cell C is shown, but the unit battery is not limited to this, and may be composed of a plurality of cells C.

- In the above embodiment, an example in which the DC power supply 21 includes only one battery module composed of cells C1 to C9 is shown, but the present invention is not limited to this, and the DC power supply 21 may include a plurality of battery modules. . In this case, a battery monitoring device 40 is provided for each battery module, and the control device 30 controls the plurality of battery monitoring devices 40 .

Each battery monitoring device 40 has the same configuration. That is, each battery monitoring device 40 is shared. On the other hand, the number of cells C included in the battery module corresponding to each battery monitoring device 40 varies depending on vehicle specifications. Therefore, in at least one battery module, the number of cells C becomes less than 12, and in the corresponding battery monitoring device 40, the disconnection detection terminal may intervene. The control device 30 stores information on the unconnected detection terminals in each battery monitoring device 40, and in the equalization process, based on this information, the specific switching element 43A and the non-specific switching element 43B are set and turned on/off. You can switch.

- In the above embodiment, for the unconnected detection terminals Y10 to Y12, the specific switching element 43A is set to the switching element 43 connected between the 12th connection point X12 and the 13th detection terminal Y13. However, it is not limited to this. The specific switching element 43A may be set to any switching element 43 connected between the ninth connection point X9 and the thirteenth detection terminal Y13.

- In the above-described embodiment, an example in which the protection circuit 42 is provided for the connection lines L1 to L13 is shown, but the protection circuit 42 does not necessarily have to be provided. Also, the configuration of the protection circuit 42 is not limited to the configuration described above.

・When the protection circuit 42 is not provided, if the disconnection detection terminals Y10 to Y12 are connected to the ninth detection terminal Y9 or the thirteenth detection terminal Y13, the disconnection detection terminals Y10 to Y12 are connected to the ninth detection terminal Y10 to Y12 by a jumper wire or the like. It must be connected to the terminal Y9 or the thirteenth detection terminal Y13. Therefore, the battery monitoring system 100 needs to be redesigned, and the addition of jumper wires increases the manufacturing cost of the battery monitoring system 100 .

The control device 30 of the present embodiment connects the unconnected detection terminals Y10 to Y12 to the ninth detection terminal Y9 or the thirteenth detection terminal Y13 using the switching element 43 provided in the monitoring IC 41. Therefore, the protection circuit 42 is Even if it is not provided, the battery monitoring system 100 can be shared.

- In the above-described embodiment, an example in which diagnostic processing is performed has been shown, but diagnostic processing does not necessarily have to be performed.

- In the above embodiment, an example in which the switching element 43 and the voltage detection unit 45 are provided in the monitoring IC 41 is shown, but the present invention is not limited to this. Arrangement may be possible.

21 DC power supply 30 control device 40 battery monitoring device 43 switching element 43A specific switching element 43B non-specific switching element 45 voltage detector 100 battery monitoring system C1 to C9 Cells, L1 to L13, connection lines, X1 to X10, connection points, Y10 to Y12, unconnected detection terminals.

Claims (5)

A monitoring device (40) applied to an assembled battery (21) comprising a plurality of unit cells (C1 to C9) connected in series and monitoring the assembled battery, and a control device (30) controlling the monitoring device A battery monitoring system (100) comprising:
The assembled battery includes n (n≧3 ) connection points (X1 to X10),
The monitoring device has m (m≧4) detection terminals (Y1 to Y13), and connection lines (L1 to L13) connected to the i-th detection terminal among the m detection terminals. and a connection line connected to the i+1-th detection terminal, a switching element (43) for opening and closing between these connection lines, and a voltage detection section (45) for detecting the voltage between these connection lines and are connected in parallel,
m is greater than n, the m detection terminals include unconnected detection terminals (Y10 to Y12) that are not connected to the connection points, and in the assembled battery, among the plurality of unit batteries, In the specific unit battery (C9), between the first detection terminal (Y13) connected to the connection point on the positive terminal side and the second detection terminal (Y9) connected to the connection point on the negative terminal side, the connected to the monitoring device so that an unconnected detection terminal intervenes,
The control device is
an equalization determination unit that determines whether or not to perform equalization processing for each of the unit batteries;
When the equalization determination unit determines to perform the equalization process, a plurality of connected lines between a connection line connected to the first detection terminal and a connection line connected to the second detection terminal any one specific switching element (43A) among the switching elements of is turned off, and the switching elements (43B) other than the specific switching element are turned on, and the voltage detector connected in parallel to the specific switching element a detection processing unit that detects the voltage of the specific unit battery using a unit. The control device is
a discharge determination unit that determines whether or not to equalize discharge the specific unit battery based on the voltage of the specific unit battery detected by the detection processing unit;
A plurality of switching elements connected between a connection line connected to the first detection terminal and a connection line connected to the second detection terminal when it is determined that the specific unit battery is to be equalized discharge. 2. The battery monitoring system according to claim 1, further comprising an equalization unit that performs equalization discharge in a state in which all of the are turned on. The first detection terminal is connected to a connection point on the negative terminal side of the unit battery on the lowest potential side, and the n-th detection terminal is connected to a connection point on the positive terminal side of the unit battery on the highest potential side. is connected to
3. The battery monitoring system according to claim 1, wherein the monitoring device is supplied with power from a connection line connected to the first detection terminal and a connection line connected to the nth detection terminal. In the monitoring device, a capacitor (53) having a predetermined capacity is provided between the connection line connected to the i-th detection terminal and the connection line connected to the (i+1)-th detection terminal, and the switching element and the voltage detection. is connected in parallel with the
The equalization determination unit determines whether or not to perform the equalization process when a start switch (31) of the battery monitoring system is in an off state,
The control device includes a plurality of switching devices connected between a connection line connected to the first detection terminal and a connection line connected to the second detection terminal when the activation switch is in an ON state. 4. The battery monitoring system according to any one of claims 1 to 3, further comprising a state control section that always turns on the switching elements other than the specific switching element among the elements. The control device is
an acquisition unit that acquires a physical quantity that expresses the amount of charge of each unit battery;
5. The battery monitoring system according to any one of claims 1 to 4, further comprising a specifying unit that specifies the unconnected detection terminal based on the physical quantity.

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