KR100964422B1 - Abnormality diagnostic device - Google Patents

Abstract

The fault diagnosis apparatus is configured to diagnose a fault in a battery pack having a plurality of cells connected in series. Each of the plurality of diagnostic voltage detection circuits is configured to detect one of a voltage across a corresponding one of the switches and a voltage across a corresponding one of the resistors of the discharge circuit. The fault diagnosis control section is configured to perform a first diagnostic operation in which switches corresponding to every other battery are turned on and a second diagnostic operation in which all switches are turned on, and are also detected by the diagnostic voltage detection circuit during the first diagnostic operation. And to determine whether there is a disconnection in the electrical connection or an abnormality in one of the switches based on the voltage that is made and the voltage detected by the diagnostic voltage detection circuit during the second diagnostic operation.

Battery voltage detection circuit, discharge circuit, switch drive circuit, diagnostic voltage detection circuit, abnormal diagnostic control section

Description

Fault diagnosis device {ABNORMALITY DIAGNOSTIC DEVICE}

The present invention relates to an abnormality diagnosis apparatus for a battery pack configured to detect whether there is a break in an electrical connection between a cell and a detection terminal provided between terminals of the battery.

The battery pack generally includes a plurality of cells and a plurality of detection terminals for detecting a voltage between the terminals of the battery. Japanese Laid-Open Patent Publication No. 2001-157367 discloses an apparatus for detecting whether there is a break in an electrical connection between a battery such as a battery pack and a detection terminal. Conventional apparatus controls the switch to short-circuit the detection terminals of the battery for a predetermined time and then cancel the short circuit. If after a predetermined time has elapsed, the voltage between the detection terminals is almost the same as when the detection terminal is shorted, the device determines that the electrical connection between the battery and the detection terminal is disconnected.

Japanese Laid-Open Patent Publication No. 2005-168118 discloses another apparatus configured to alternately short-circuit a connection between detection terminals of a plurality of batteries forming a battery pack, in order to determine whether the battery is over discharged or there is a disconnection of wiring. have.

In view of the above, it will be apparent to those skilled in the art that an improved abnormality diagnosis apparatus is required herein. The present invention addresses these requirements in the art, as well as other requirements that will be apparent to those skilled in the art from this specification.

The devices described in the above-mentioned references are not actually disconnected from the electrical connection between the battery and the detection terminal, but are disconnected from the electrical connection between the battery and the detection terminal even when the switch portion used to short-circuit the detection terminal of the battery is broken. Can be determined.

One object of the present invention is to provide an abnormality diagnosis apparatus that more accurately determines when a disconnection occurs in the electrical connection of a battery.

Therefore, as an abnormality diagnosis apparatus for diagnosing an abnormality in a battery pack having a plurality of batteries connected in series, a plurality of battery voltage detection circuits, a plurality of discharge circuits, a switch driving circuit, a plurality of diagnostic voltage detection circuits, and an abnormal diagnostic control An abnormality diagnosis device having a section is provided. Each of the battery voltage detection circuits is connected in parallel to a corresponding one of the batteries of the battery pack to detect the voltage of the battery. Each of the discharge circuits is connected in parallel to a corresponding one of the cells to selectively discharge its power, and each discharge circuit has a switch and a resistor connected in series. The switch drive circuit is connected to a switch of the discharge circuit to selectively turn on and turn off the switch. Each of the diagnostic voltage detection circuits is electrically connected to a corresponding one of the discharge circuits to detect a voltage across a corresponding one of the switches and a voltage across a corresponding one of the resistors. The abnormal diagnostic control section is configured to control the switch driving circuit to perform a first diagnostic operation in which switches corresponding to every other battery are turned on and a second diagnostic operation in which all switches are turned on. The abnormal diagnostic control section further includes a discharge corresponding to one battery based on the voltage detected by the diagnostic voltage detection circuit during the first diagnostic operation and the voltage detected by the diagnostic voltage detection circuit during the second diagnostic operation. And to determine if there is a break in the electrical connection between the circuits or if there is an abnormality in one of the switches.

These and other objects, features, aspects, and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which describes preferred embodiments of the present invention with reference to the accompanying drawings.

According to the abnormality diagnosis apparatus of the present invention, it is possible to more accurately determine when a disconnection occurs in the electrical connection of the battery.

Reference is now made to the accompanying drawings, which form a part of this specification.

Selected embodiments of the present invention will be described with reference to the drawings. Those skilled in the art, having read the present specification, should understand that the following detailed description is provided by way of example only and is not intended to limit the invention to the claims and their equivalents.

First, referring to FIG. 1, there is shown an abnormality diagnosis apparatus according to a first embodiment of the present invention. 1 is a schematic diagram of a battery pack 1 provided with a battery fault diagnosis apparatus of the first embodiment. As shown in Fig. 1, the battery pack 1 includes a plurality of rechargeable batteries (e.g., lithium battery cells) (C1 to Cn, where "n" is a natural number) connected in series. The abnormality diagnosis apparatus includes a plurality of switches SW1 to SWn and a plurality of resistors R1 to Rn. One of the switches SW1 to SWn and a corresponding resistor of the resistors R1 to Rn are connected in series to form a discharge circuit, which is connected in parallel to the corresponding one of the cells C1 to Cn. For example, a discharge circuit having a switch SW1 and a resistor R1 connected in series is connected in parallel with the battery C1 as shown in FIG. The switches SW1 to SWn have a transistor, for example. The abnormality diagnosis apparatus further includes an abnormality diagnosis section 10 (an abnormality diagnosis control section) having a switch driving circuit configured to selectively control the on / off states of the switches SW1 to SWn. The resistance values of the resistors R1 to Rn are all the same.

As shown in Fig. 1, the line L0 connects between the positive electrode of the highest cell C1 and the switch SW1, and the lines L1 to Ln connect the negative electrode and the resistance of the corresponding cell among the cells C1 to Cn. The corresponding resistors among R1 to Rn are connected. That is, the lines L0 to Ln are connection lines which function to connect each of the batteries C1 to Cn to corresponding discharge circuits including switches SW1 to SWn and resistors R1 to Rn connected in series. . As used herein, "highest cell" or "highest order cell" means one of the cells of a battery pack that is electrically disposed at the positive end of a series-connected cell (eg, shown in FIG. In the illustrated embodiment, the battery C1) is referred to.

Furthermore, the abnormality diagnosis apparatus further includes a plurality of resistance voltage detection circuits B1 to Bn (diagnostic voltage detection circuits) provided for each of the resistors R1 to Rn corresponding to each of the batteries C1 to Cn. do. Each of the resistance voltage detection circuits B1 to Bn is configured to detect a voltage applied to a corresponding resistance among the resistors R1 to Rn and send the detected voltage value to the abnormality diagnosis section 10.

In addition, the abnormality diagnosis apparatus includes a plurality of battery voltage detection circuits D1 to Dn provided for each of the batteries C1 to Cn, as shown in FIG. Each of the battery voltage detection circuits D1 to Dn is configured to detect a voltage applied to a corresponding battery among the cells C1 to Cn and send the detected voltage value to the abnormality diagnosis section 10.

The fault diagnosis section 10 preferably includes a microcomputer incorporating a fault diagnosis control program as described later. The fault diagnosis section 10 may also include input interface circuits, output interface circuits, and other conventional components such as storage devices such as read only memory (ROM) devices and random access memory (RAM) devices. The microcomputer in the fault diagnosis section 10 is programmed to control the on / off states of the switches SW1 to SWn. The memory circuit stores a control program driven by the processor circuit and the processing result. The fault diagnosis section 10 is operatively coupled to the switches SW1 to SWn, the resistance voltage detection circuits B1 to Bn, the battery voltage detection circuits D1 to Dn, and other components in a conventional manner. The internal RAM of the fault diagnosis section 10 stores operation flags and statuses of various control data. The fault diagnosis section 10 may selectively control the components of the control system according to the control program. Those skilled in the art will appreciate from this specification that the precise structure and algorithms for the fault diagnosis section 10 can be any combination of hardware and software to carry out the functions of the present invention.

The abnormality diagnosis section 10 controls the on / off state of the switches SW1 to SWn, checks whether there is an error in the switches SW1 to SWn, disconnects the lines L0 to Ln, and the batteries C1 to Cn. Is determined based on the voltage received at the resistance voltage detection circuits B1 to Bn and the voltage received at the battery voltage detection circuits D1 to Dn. How the abnormality diagnosis section 10 makes these determinations will be described later.

The voltages of the cells C1 to Cn stay within a predetermined range due to the characteristics of the battery. In a first embodiment, the predetermined range is about 1.0V (volts) to about 4.35V. That is, the battery voltage does not fall below 1.0V and does not exceed 4.35V. When the cells C1 to Cn are normal, the battery voltage will lie in another predetermined range (e.g., 2.0V to 4.3V). The abnormality diagnosis section 10 includes one of the batteries C1 to Cn if the battery voltage detected by the corresponding battery voltage detection circuits D1 to Dn is equal to or less than a predetermined overdischarge threshold V1 (for example, 2.0V). And determine that the battery is in an overcharged state and determine that the battery is in an overcharged state if the detected battery voltage is above a predetermined overcharge threshold V2 (e.g., 4.3V).

The fault diagnosis method using the switches SW1 to SWn performed will now be described. In this description, the switch SW1 will be used for explanation, but the same method applies to the other switches SW2 to SWn. When the switch SW1 is turned on, a current flows from the battery C1 to the resistor R1, and the voltage applied to the resistor R1 is the on-resistance voltage of the switch SW1 at the voltage of the battery C1. It is a voltage value obtained by subtracting. When the switch SW1 is turned off, no current flows to the resistor R1, and the voltage across the resistor R1 becomes almost 0V.

The abnormality diagnosis section 10 is abnormal to the switch SW1 based on the control signal for turning on and off the switch SW1 and the voltage applied to the resistor R1 detected by the resistance voltage detection circuit B1. Or determine if there is a failure. More specifically, the fault diagnosis section 10 has a switch SW1 if a voltage applied to the resistor R1 is within a predetermined range (for example, 1.0 V to 3.8 V) when control is made to turn on the switch SW1. Is determined to be normal. In addition, the abnormality diagnosis section 10 has a switch SW1 when the voltage applied to the resistor R1 when the control is made to turn off the switch SW1 is less than or equal to a predetermined voltage V3 (for example, 0.1 V). And determine to be normal.

Even when the battery C1 is overcharged or charged to a maximum battery voltage of 4.35 V, the voltage value obtained by subtracting the on resistance voltage of the switch SW1 from the battery voltage is less than 3.8 V (ie, 1.0 V to 3.8 V). The voltage across the resistor R1 when the switch SW1 is turned on will be within the predetermined voltage range. In addition, even when the battery C1 is over discharged when the switch SW1 is turned on, the voltage applied to the resistor R1 will be within a predetermined voltage range (ie, 1.0 V or more).

2 is a flowchart for explaining a diagnostic process performed by the abnormality diagnosis apparatus according to the first embodiment. The abnormality diagnosis section 10 performs the control process of step S10 at any time to determine whether there is an error in the switches SW1 to SWn, whether there is a disconnection in the lines L0 to Ln, and whether each battery is over discharged or overcharged. It is configured to start.

In step S10 (first diagnostic operation), the abnormality diagnosis section 10 starts with the highest battery C1 and then every other one of the batteries of the battery pack 1 (every one of the batteries of the battery pack 1). And a signal for turning on the switches SW1, SW3, etc. corresponding to the < RTI ID = 0.0 > That is, the fault diagnosis section 10 is configured to issue a signal acting to turn on the switches SW1, SW3, etc. corresponding to the odd-numbered cells C1, C3, etc. On the other hand, the switches SW2, SW4, etc. corresponding to the even-numbered batteries C2, C4, C6, etc. are kept in the OFF state.

Then, in step S20 (diagnostic voltage detection step), the abnormality diagnosis section 10 receives from the resistance voltage detection circuits B1 to Bn whether each voltage (resistance voltage) applied to the resistors R1 to Rn is normal. And make a determination based on the voltage value. That is, the resistance value of each of the resistors R1, R3, R5, etc. corresponding to the odd-numbered switches SW1, SW3, etc. (turned on) is such that the voltage applied to the resistors is within a predetermined voltage range (eg, 1.0 V). To 3.8V), it is determined to be normal. On the other hand, the resistance value of each of the resistors R2, R4, R6, etc. corresponding to the even-numbered switches SW2, SW4, etc. (turned off) has a voltage V3 (for example). For example, it is determined to be normal if it is 0.1 V or less. When the voltage across the resistors R1 to Rn is detected, the fault diagnosis section 10 is preferably configured to turn off the switches SW1, SW3, etc. corresponding to the odd-numbered cells C1, C3, etc. Do.

If it is determined in step S20 that all the resistance voltages are normal, the abnormality diagnosis section 10 proceeds to step S30.

In step S30 (battery voltage detection step), the abnormality diagnosis section 10 includes any of the battery voltages detected by the battery voltage detection circuits D1 to Dn at a predetermined overcharge threshold value V2 (e.g., 4.3V). It is configured to determine whether it is abnormal. If there is a battery voltage above the predetermined overcharge threshold V2, the fault diagnosis section 10 proceeds to step S40.

In step S40, the abnormality diagnosis section 10 determines that there is an overcharged battery. Under these circumstances, the user may know the presence of an overcharged battery, for example by illumination of an indicator light (not shown).

On the other hand, if the abnormality diagnosis section 10 determines that none of the battery voltages detected by the battery voltage detection circuits D1 to Dn is equal to or greater than the predetermined overcharge threshold V2 (No in step S30), the abnormality diagnosis section ( 10) proceeds to step S50.

In step S50, the abnormality diagnosis section 10 is configured to determine whether any of the battery voltages detected by the battery voltage detection circuits D1 to Dn is equal to or less than a predetermined overdischarge threshold V1 (for example, 2.0V). do. If there is a battery voltage that is equal to or less than the predetermined overdischarge threshold V1, the abnormality diagnosis section 10 proceeds to step S60.

In step S60, the abnormality diagnosis section 10 determines that there is an over discharged battery. Under such circumstances, the user may know the presence of the overdischarged battery, for example by illumination of an indicator light (not shown).

On the other hand, if the abnormality diagnosis section 10 determines that none of the battery voltages detected by the battery voltage detection circuits D1 to Dn is below the predetermined overdischarge threshold value V1 (No in step S50), the abnormality diagnosis section 10 proceeds to step S70.

In step S70 (third diagnostic operation), the fault diagnosis section 10 is configured to issue a signal acting to turn on the switches SW2, SW4, etc. corresponding to the even-numbered cells C2, C4, etc. . On the other hand, the switches SW1, SW3, etc. corresponding to the odd-numbered batteries C1, C3, etc. are kept in the OFF state.

Thereafter, in step S71, the abnormality diagnosis section 10 determines whether the respective voltages (resistance voltages) applied to the resistors R1 to Rn are normal based on the voltage values received from the resistance voltage detection circuits B1 to Bn. It is configured to. That is, the resistance value of each of the resistors R2, R4, etc. corresponding to the even-numbered switches SW2, SW4, etc. (turned on) has a voltage applied to the resistors in a predetermined voltage range (eg, 1V to 3.8V). Is determined to be normal. The resistance value of each of the resistors R1, R3, etc. corresponding to the odd-numbered switches SW1, SW3, etc. (turned off) has a predetermined voltage V3 (eg, 0.1 V). If it is below, it is determined to be normal.

If the abnormality diagnosis section 10 determines that any one of the respective voltages applied to the resistors R1 to Rn is not normal (No in step S71), the abnormality diagnosis section 10 proceeds to step S72.

In step S72, the fault diagnosis section 10 has a switching fault (failure) or at least one of the odd number switches SW1, SW3, etc. cannot turn off the switch, or the even number switches SW2, SW4, etc. At least one of them is configured to have a switching abnormality (failure) that cannot turn on the switch. Under these circumstances, the user can know the abnormality by, for example, the illumination of an indicator light (not shown).

On the other hand, if the abnormality diagnosis section 10 determines that each voltage (resistance voltage) applied to the resistors R1 to Rn is normal (Yes in step S71), the abnormality diagnosis section 10 proceeds to step S73.

In step S73, the abnormality diagnosis section 10 has no disconnection in the lines L0 to Ln, no abnormality in the switches SW1 to SWn (i.e., all the switches SW1 to SWn are normal), and any battery. (C1 to Cn) is also determined to not be overdischarged or overcharged.

In step S20, when the abnormality diagnosis section 10 determines that any of the resistance voltages is not within a predetermined voltage range (for example, 1V to 3.8V), the abnormality diagnosis section 10 proceeds to step S80. In this case, one of the following (1) to (4) of the form described below exists: (1) a disconnection exists in the line L0; (2) a disconnection exists in one of the lines L1 to Ln; (3) at least one of the cells C1 to Cn is in an overdischarge or overcharge state; And (4) at least one of the switches SW1 to SWn is in an abnormal state. In step S80 and subsequent steps, the abnormality diagnosis section 10 identifies which type of abnormality exists.

3 is a schematic diagram showing the case where all the switches SW1 to SWn are in the on state and there is a disconnection in the line L0. In this case, the voltage detected by the resistance voltage detection circuit B1 is almost 0V. Therefore, the voltage detected by the resistance voltage detection circuit B1 is not within the normal voltage range (for example, 1.0 V to 3.8 V) when the switch SW1 is in the on state. In addition, since the voltage detected by the battery voltage detection circuit D1 is almost 0 V, the abnormality diagnosis section 10 determines that the voltage detected by the battery voltage detection circuit D1 is equal to or less than the predetermined over-discharge threshold value V1. .

4 is a schematic diagram showing the case where all the switches SW1 to SWn are in the on state and there is a disconnection in the line L2. In this example, neither of the batteries C1 to Cn is overdischarged or overcharged (that is, the battery voltages of all the batteries C1 to Cn are normal). When disconnection occurs in the line L2, current flows from the positive electrode of the battery C2 to the negative electrode of the battery C3 through the switch SW2, the resistor R2, the switch SW3, and the resistor R3. Under these conditions, since the average voltages of the cells C2 and C3 act on each of the resistors R2 and R3, both of the voltages detected by the resistance voltage detection circuits B2 and B3 are switches SW2 and SW3. ) Is within the normal voltage range when on. In addition, since the voltage detected by both the battery voltage detection circuits D2 and D3 is equal to the average of the voltages of the battery C2 and the battery C3, both detection voltages are higher than the predetermined overdischarge threshold V1 and the predetermined overcharge It is lower than the threshold value V2. Although the description just described with reference to FIG. 4 described the detection voltage occurring when disconnection occurs in line L2, the same situation regarding the detection voltage is in addition to the line L1 in addition to the line L0 connected to the anode of the highest cell C1. It also occurs when a disconnection occurs in any of the lines L3, L4, ...,).

Fig. 5 is a schematic diagram showing a case where the switch SW3 remains off even when an on-signal is transmitted from the fault diagnosis section 10, so that an abnormality exists in the switch SW3. All switches other than the switch SW3 are in an on state as shown in FIG. In this example, neither of the batteries C1 to Cn is overdischarged or overcharged (that is, the battery voltages of all the batteries C1 to Cn are normal). In this case, the voltage detected by the resistance voltage detection circuit B3 is almost 0 V, and therefore is not within the normal voltage range when the switch SW3 is in the on state. In addition, since the voltage detected by the battery voltage detection circuit D3 is equal to the voltage of the battery C3, the detected voltage is higher than the predetermined overdischarge threshold V1 and lower than the predetermined overcharge threshold V2. Although the description just described with reference to Fig. 5 has described a detection voltage occurring when an abnormality occurs in the switch SW3, the same situation regarding the detection voltage may be any of the switches SW1, SW2, SW4, ..., SWn. It also happens when something goes wrong with things.

As described above, when one of the batteries C1 to Cn is in the overdischarge state, the voltage detected by one of the battery voltage detection circuits D1 to Dn, corresponding to the overdischarged battery, becomes a predetermined overdischarge threshold value ( V1) (for example, 2.0V) or less. Similarly, when the battery is in the overcharged state, the voltage detected by the battery voltage detection circuit corresponding to the overcharged battery is equal to or higher than the predetermined overcharge threshold V2 (for example, 4.3 V). Even if the battery is over discharged or overcharged, the resistance voltage detected by the resistance voltage detection circuit will be within the normal voltage range (e.g., 1.0V to 3.8V) when the switch is on.

Referring back to the flowchart of FIG. 2, in step S80 (second diagnostic operation), the abnormality diagnosis section 10 is configured to issue a signal to turn on all the switches SW1 to SWn. Thereafter, the abnormality diagnosis section 10 proceeds to step S90.

In step S90, the abnormality diagnosis section 10 determines whether the respective voltages (resistance voltages) applied to the resistors R1 to Rn are normal based on the voltage values received from each of the resistance voltage detection circuits B1 to Bn. It is configured to. That is, the abnormality diagnosis section 10 determines that the resistance voltage of the resistors is normal if the voltage detected by each of the resistance voltage detection circuits B1 to Bn is within a predetermined voltage range (for example, 1.0V to 3.8V). do. If any of the detected resistance voltages is not within the predetermined voltage range in step S90 (No in step S90), the abnormality diagnosis section 10 determines that there is an abnormal resistance voltage, and therefore the abnormality diagnosis section 10 performs step S150. Proceeds. On the other hand, if the abnormality diagnosis section 10 determines that the resistance voltage is normal in step S90 (Yes in step S90), the abnormality diagnosis section 10 proceeds to step S100.

In step S100, the abnormality diagnosis section 10 is configured to determine whether any of the battery voltages detected by the battery voltage detection circuits D1 to Dn is greater than or equal to a predetermined overcharge threshold V2 (e.g., 4.3V). do. If it is determined in step S100 that all of the detected battery voltages are smaller than the predetermined overcharge threshold value V2 (No in step S100), the abnormality diagnosis section 10 proceeds to step S110. On the other hand, if the abnormality diagnosis section 10 determines that any one of the detected battery voltages is equal to or greater than the predetermined overcharge threshold V2 (Yes in step S100), the abnormality diagnosis section 10 proceeds to step S140.

In step S140, the abnormality diagnosis section 10 determines that there is an overcharged battery. Under these circumstances, the user can know the abnormality by, for example, the illumination of an indicator light (not shown).

In step S110, the abnormality diagnosis section 10 is configured to determine which of the battery voltages detected by the battery voltage detection circuits D1 to Dn is below a predetermined overdischarge threshold value V1 (for example, 2.0V). do. If the abnormality diagnosis section 10 determines that all of the detected battery voltages are larger than the predetermined over-discharge threshold value V1 (No in step S110), the abnormality diagnosis section 10 proceeds to step S120. On the other hand, if the abnormality diagnosis section 10 determines that any one of the detected battery voltages is equal to or less than the predetermined over-discharge threshold value V1 (Yes in step S110), the abnormality diagnosis section 10 proceeds to step S130.

In step S130, the abnormality diagnosis section 10 determines that there is an over discharged battery. Under these circumstances, the user can know the abnormality by, for example, the illumination of an indicator light (not shown).

In step S120, the abnormality diagnosis section 10 has a disconnection in any of lines L1 to Ln, that is, a line other than the highest line L0 connected to the positive electrode of the highest battery C1 as described above with reference to FIG. 4. Is determined. Under these circumstances, the user can know the abnormality by, for example, the illumination of an indicator light (not shown).

On the other hand, in step S150, the abnormality diagnosis section 10 determines whether any of the battery voltages detected by the battery voltage detection circuits D1 to Dn is equal to or less than a predetermined over-discharge threshold value V1 (for example, 2.0V). And to determine. If the abnormality diagnosis section 10 determines that all of the detected battery voltages are greater than the predetermined overdischarge threshold V1 (No in step S150), the abnormality diagnosis section 10 proceeds to step S160. On the other hand, if the abnormality diagnosis section 10 determines that any of the detected battery voltages is equal to or less than the predetermined over-discharge threshold value V1 (Yes in step S150), the abnormality diagnosis section 10 proceeds to step S170.

In step S160, as described above with reference to FIG. 5, the abnormality diagnosis section 10 determines that an abnormality has occurred in at least one of the switches SW1 to SWn. Under these circumstances, the user can know the abnormality by, for example, the illumination of an indicator light (not shown).

In step S170, as described above with reference to FIG. 3, the abnormality diagnosis section 10 determines that disconnection has occurred in the highest line L0 connected to the positive electrode of the highest battery C1. Under these circumstances, the user can know the abnormality by, for example, the illumination of an indicator light (not shown).

6 is a table summarizing a method for distinguishing different types of abnormalities based on the control states, the resistance voltages, and the battery voltages of the switches SW1 to SWn. In the above form, the switching of any of the switches SW1 to SWn is abnormal, the disconnection in the line L0 connected to the anode of the highest cell C1, the disconnection in any line of the lines L1 to Ln, and the batteries C1 to Overdischarge of any of Cn) and overcharge of any of the cells C1 to Cn.

The abnormality diagnosing apparatus according to the first embodiment has a plurality of discharge circuits, each discharge circuit having a resistance of one of the resistors R1 to Rn connected in parallel with one of the cells C1 to Cn of the battery pack 1. And one of the switches SW1 to SWn. Each pair of switches SW1 to SWn and resistors R1 to Rn are connected in series. According to the abnormality diagnosing apparatus according to the first embodiment, the voltage abnormality of the batteries C1 to Cn, the disconnection of the electrical connection between the batteries C1 to Cn, and the switches SW1 to SWn of the discharge circuits, The switching abnormality is detected and confirmed based on the control state of the switches SW1 to SWn, the voltages of the batteries C1 to Cn, and the voltage applied to the resistors R1 to Rn (between terminals of) of the discharge circuit. In this way, the voltage abnormality of the batteries C1 to Cn, the disconnection of the electrical connection, and the switching abnormality of the switches SW1 to SWn can be detected and confirmed according to the abnormality form.

In particular, the abnormality diagnosing apparatus according to the first embodiment includes each of the resistance voltages when the on / off state of the switches SW1 to SWn is controlled to short the batteries C1 to Cn every other time. If it is within a predetermined normal voltage range (for example, 1.0V to 3.8V) according to the on / off state of SWn, it is configured to determine that a disconnection of the electrical connection exists in any of the connection lines L0 to Ln. In this way, when there is no break in the electrical connection, the fact that there is no break in the electrical connection can be reliably detected.

The abnormality diagnosing apparatus according to the first embodiment also includes any of the resistance voltages when the on / off state of the switches SW1 to SWn is controlled to short the batteries C1 to Cn every other predetermined voltage range (eg, For example, if it is within 1.0V to 3.8V, and all the resistance voltages are within a predetermined normal voltage range after all the switches SW1 to SWn are turned on, the connection line other than the connection line L0 connected to the positive electrode of the highest cell It is configured to determine that a disconnection of the electrical connection exists in one of (L1 to Ln). More specifically, if any of the battery voltages is above a predetermined overcharge threshold V2 (for example, 4.3 V) when all of the switches SW1 to SWn are turned on so that all of the batteries C1 to Cn are shorted, then an abnormality diagnosis is made. The device determines that an overcharged battery is present. On the other hand, if any of the battery voltages is equal to or less than the predetermined overdischarge threshold value V1 (for example, 2.0V), the abnormality diagnosis device determines that the overdischarged battery exists. In addition, when all of the battery voltages are smaller than the predetermined overcharge threshold V2 and greater than the predetermined overdischarge threshold V1, the abnormality diagnosis apparatus connects the connection lines L1 to other than the connection line L0 connected to the positive electrode of the highest battery C1. It is determined that disconnection exists in one of Ln). In this way, the presence of an overcharged battery, the presence of an overcharged battery, and the disconnection of the connection lines L1 to Ln other than the connection line L0 connected to the positive electrode of the highest cell C1 can be reliably detected, respectively. Can be.

In the abnormality diagnosis apparatus according to the first embodiment, any of the resistance voltages is a predetermined voltage range when the on / off state of the switches SW1 to SWn is controlled to the on-state to short-circuit all of the batteries C1 to Cn. (For example, if it is not within 1.0 V to 3.8 V), there is a switching abnormality in the switches SW1 to SWn, or there is a disconnection of the electrical connection in the connection line L0 connected to the positive electrode of the highest cell C1. And to determine. More specifically, when all of the switches SW1 to SWn are turned on so that all of the batteries are shorted, if the battery voltage is below a predetermined overdischarge threshold V1 (for example, 2.0V), the abnormality diagnosing apparatus is the highest battery C1. It is determined that a disconnection exists in the connection line L0 connected to the anode of. In this way, the disconnection in the connection line L0 connected to the positive electrode of the highest cell C1 can be reliably detected. On the other hand, when all of the battery voltages are larger than the predetermined overdischarge threshold when all of the switches SW1 to SWn are turned on so that all of the batteries C1 to Cn are shorted, the abnormality diagnosis apparatus indicates that there are switching abnormalities in the switches SW1 to SWn. Determine. In this way, switching abnormalities in the switches SW1 to SWn can be reliably detected.

The first embodiment of the present invention can detect and confirm the disconnection of one of the lines L0 to Ln, the abnormality of one of the switches SW1 to SWn, and the abnormality as an over-discharged or overcharged battery. Not only can it be informed by the indicator light, but it can also alter the operation of the battery to accommodate the specific abnormality that has occurred.

For example, if a disconnection occurs in one of the lines L0 to Ln, the voltage applied to the battery corresponding to the disconnected line cannot be detected, and power consumption from the battery pack 1 or charging of the battery pack 1 is lost. It is necessary to prohibit or restrict them. On the other hand, if an abnormality occurs in any of the switches SW1 to SWn, the voltage applied to the batteries C1 to Cn can be detected, and from the battery pack 1 as long as the voltages of the batteries C1 to Cn are normal. Power consumption or charging of the battery pack 1 can be continued. In this case, instead, for example, it is possible to limit the amount of power and prompt the user to repair the battery pack 1. That is, according to the above aspect, it may not be necessary to prohibit the power consumption from the battery pack 1 or the charging of the battery pack 1. In this case (for example, when there is a switching abnormality in one of the switches SW1 to SWn), the power consumption from the battery pack 1 or the charging of the battery pack 1 can be continued, so that the first of the present invention The embodiment provides a desirable effect from the point of view of the user.

Second Embodiment

7 and 8, a fault diagnosis apparatus according to the second embodiment will now be described. In view of the similarity between the first embodiment and the second embodiment, parts of the second embodiment that are identical to parts of the first embodiment will be given the same reference numerals as parts of the first embodiment. Moreover, the description of the parts of the second embodiment that are identical to the parts of the first embodiment may be omitted for simplicity. Parts of the second embodiment that are different from parts of the first embodiment will be referred to as single quotes (').

In the abnormality diagnosing apparatus of the first embodiment, the voltage across the resistors R1 to Rn is detected by the resistance voltage detection circuits B1 to Bn, whereas the abnormality diagnosing apparatus of the second embodiment applies to the resistors R1 to Rn. It differs from the abnormality diagnosis apparatus of the first embodiment in that a plurality of switch voltage detection circuits E1 to En (diagnostic voltage detection circuits) configured to detect voltages applied to the switches SW1 to SWn instead of voltages are provided.

7 is a schematic diagram of a battery pack 1 provided with an abnormality diagnosing device according to a second embodiment.

FIG. 8 is a flowchart showing a diagnostic process performed by the fault diagnosis apparatus of the second embodiment shown in FIG. The fault diagnosis section 10 ′ of the second embodiment can be used at any time to determine whether there is an error in the switches SW1 to SWn, whether there is a disconnection in the lines L0 to Ln, and whether each battery is over discharged or overcharged. And start the diagnostic process shown in FIG.

In step S210, the abnormality diagnosis section 10 ′ switches from one of the cells C1 to Cn of the battery pack 1 to the switches SW2 and SW4 starting with the next cell after the highest cell C1. , Etc.). That is, in the second embodiment, the fault diagnosis section 10 'is configured to transmit a signal for turning on the switches SW2, SW4, etc. corresponding to the even-numbered cells C2, C4, etc. On the other hand, the switches SW1, SW3, etc. corresponding to the odd-numbered batteries C1, C3, etc. are kept in the OFF state.

Subsequently, in step S220, the abnormality diagnosis section 10 ′ is configured to determine whether the respective voltages applied to the switches SW1 to SWn are normal based on the voltage values detected by the switch voltage detection circuits E1 to En. do. More specifically, the fault diagnosis section 10 ′ has a voltage of all of the even-numbered switches SW2, SW4, etc. (turned on) is less than or equal to a predetermined voltage (for example, 1.0V), and the odd-numbered switches SW1, SW3, Etc. (turned off) is configured to determine that the switch voltage is normal if it is higher than the predetermined voltage.

If in step S220 the abnormality diagnostic section 10 'determines that all switch voltages are normal (Yes in step S220), the abnormality diagnostic section 10' proceeds to step S230.

In step S230 (second diagnostic operation), the abnormality diagnosis section 10 'is configured to turn on all the switches SW1 to SWn.

Then, in step S240, the abnormality diagnosis section 10 'is configured to receive the switch voltages of the switches SW1 to SWn detected by the switch voltage detection circuits E1 to En. If all the switch voltages are less than or equal to a predetermined voltage (for example, 1.0 V) in step S240, the abnormality diagnosis section 10 'determines that the switch voltage is normal and proceeds to step S260. On the other hand, if any of the switch voltages in step S240 is higher than the above-mentioned voltage, the abnormality diagnosis section 10 'determines that the switch voltage is abnormal and proceeds to step S250.

In step S250, the abnormality diagnosis section 10 'indicates that all the switch voltages are normal when the even number switches SW2, SW4, etc. are turned on and the odd number switches SW1, SW3, etc. are turned off (in step S220). Yes) However, when all the switches SW1 to SWn are turned on, it is determined that the switch voltage is abnormal (No in step S240). Thus, the fault diagnosis section 10 'determines that at least one of the odd number switches SW1, SW3, etc. is in an open fault condition that cannot be turned on (i.e. cannot be opened). Thus, the fault diagnosis section 10 ′ also informs the user of the fault, for example by illumination of an indicator light (not shown).

On the other hand, if the abnormality diagnosis section 10 'in step S240 determines that all the switch voltages are normal (Yes in step S240), the abnormality diagnosis section 10' proceeds to step S260.

In step S260 (third diagnostic operation), the abnormality diagnosis section 10 'is configured to turn off all the switches SW1 to SWn.

Thereafter, in step S270, the abnormality diagnosis section 10 'is configured to receive the switch voltages of the switches SW1 to SWn detected by the switch voltage detection circuits E1 to En. If all the switch voltages are greater than the predetermined voltage (for example, 1.0V) (Yes in step S270), the abnormality diagnosis section 10 'determines that the switch voltage is normal and proceeds to step S290. On the other hand, if any of the switch voltages is equal to or lower than the predetermined voltage (No in step S270), the abnormality diagnosis section 10 'determines that the switch voltage is abnormal and proceeds to step S280.

In step S280, the abnormality diagnosis section 10 'determines that at least one of the odd number switches SW1, SW3, etc. is in a closed bad state that cannot be turned off (i.e. cannot be opened). Thus, the fault diagnosis section 10 ′ is configured to inform the user of the fault, for example by illumination of an indicator light (not shown).

On the other hand, in step S290, the abnormality diagnosis section 10 ′ indicates whether any of the battery voltages detected by the battery voltage detection circuits D1 to Dn is equal to or less than the predetermined overdischarge threshold V1 (for example, 2.0V). And to determine. If there is a battery voltage that is less than or equal to the predetermined over discharge threshold V1 (Yes in step S290), the abnormality diagnosis section 10 'proceeds to step S300.

In step S300, the abnormality diagnosis section 10 'determines that there is an over-discharged battery, and informs the user of the abnormality, for example, by illumination of an indicator light (not shown).

If in step S290 the abnormality diagnostic section 10 'determines that all battery voltages are greater than the predetermined over-discharge threshold value V1 (No in step S290), the abnormality diagnostic section 10' is not in a state of overdischarging. If not, the process proceeds to step S310.

In step S310, the abnormality diagnosis section 10 ′ is configured to determine whether any of the battery voltages detected by the battery voltage detection circuits D1 to Dn is greater than or equal to a predetermined overcharge threshold V2 (eg, 4.3 V). It is composed. If there is a battery voltage equal to or greater than the predetermined overcharge threshold V2 (Yes in step S310), the abnormality diagnosis section 10 'proceeds to step S320.

In step S320, the abnormality diagnosis section 10 'determines that there is an overcharged battery, and informs the user of the abnormality, for example, by illumination of an indicator light (not shown).

If the abnormality diagnosis section 10 'determines that all battery voltages are lower than the predetermined overcharge threshold value V2 (No in step S310) in step S310, the abnormality diagnosis section 10' determines that no battery is in an overcharge state. The flow proceeds to step S330.

In step S330, the abnormality diagnosis section 10 ′ shows that the battery pack 1 has no disconnection in the lines L0 to Ln, no switching abnormality in the switches SW1 to SWn, and there is no overdischarge or overcharged battery. It is determined that it is in a normal state at all.

Returning to step S220 again, if the abnormality diagnosis section 10 'determines that any of the switch voltages is abnormal in step S220 (No in step S220), the abnormality diagnosis section 10' proceeds to step S340.

In step S340, the abnormality diagnosis section 10 ′ is configured to turn on all the switches SW1 to SWn.

Thereafter, in step S350, the abnormality diagnosis section 10 'is configured to determine whether any of the switch voltages detected by the switch voltage detection circuits E1 to En is higher than a predetermined voltage (for example, 1.0V). . If the abnormality diagnosis section 10 'determines that any of the switch voltages is higher than the predetermined voltage (No in step S350), the abnormality diagnosis section 10' determines that an abnormal switch voltage exists and proceeds to step S360.

In step S360, the abnormality diagnosis section 10 'determines that at least one of the even-numbered switches SW2, SW4, etc. is in an open failure state that cannot be turned on (i.e., cannot be closed). Thus, the fault diagnosis section 10 ′ is configured to inform the user of the fault, for example by illumination of an indicator light (not shown).

On the other hand, if the abnormality diagnosis section 10 'determines that all switch voltages are normal in step S350 (Yes in step S350), then the abnormality diagnosis section 10' proceeds to step S370.

In step S370, the abnormality diagnosis section 10 ′ is configured to determine whether all of the battery voltages detected by the battery voltage detection circuits E1 to En are within a predetermined range (for example, 2.0V to 4.3V). If any of the battery voltages is outside the predetermined range (No in step S370), the abnormality diagnosis section 10 'proceeds to step S380.

In step S380, the abnormality diagnosis section 10 ′ indicates that all of the switch voltages are normal (Yes in step S350) but that there is a battery voltage that is not within a predetermined range when all the switches SW1 to SWn are on (step S370). No) Determined. Therefore, in step S380, the abnormality diagnosis section 10 'determines that a disconnection exists in the line L0 connected to the positive electrode of the highest cell C1. Thus, the fault diagnosis section 10 ′ is configured to inform the user of the fault, for example by illumination of an indicator light (not shown).

On the other hand, if the abnormality diagnosis section 10 'determines in step S370 that all battery voltages are within a predetermined range and is therefore normal (Yes in step S370), the abnormality diagnosis section 10' proceeds to step S390.

In step S390 (third diagnostic operation), the abnormality diagnosis section 10 'is configured to turn off all the switches SW1 to SWn.

Thereafter, in step S400, the abnormality diagnosis section 10 'is configured to determine whether all of the battery voltages detected by the battery voltage detection circuits D1 to Dn are normal, that is, within the predetermined range. If all battery voltages are normal (Yes in step S400), the abnormality diagnosis section 10 'proceeds to step S410.

In step S410, the abnormality diagnosis section 10 ′ determines that at least one of the even-numbered switches SW1, SW3, etc. is in a closed bad state that cannot be turned off (ie cannot be opened). Thus, the fault diagnosis section 10 ′ is configured to inform the user of the fault, for example by illumination of an indicator light (not shown).

On the other hand, if the abnormality diagnosis section 10 'determines that any of the battery voltages is abnormal in step S400 (No in step S400), the abnormality diagnosis section 10' proceeds to step S420.

In step S420, the abnormality diagnosis section 10 ′ is configured to determine that a disconnection exists in one of the lines L0 to Ln in addition to the line L0 connected to the positive electrode of the highest cell C1. Thus, the fault diagnosis section 10 ′ is configured to inform the user of the fault, for example by illumination of an indicator light (not shown).

Although the batteries C1 to Cn constituting the battery pack 1 are assumed to be lithium ion batteries in the first and second embodiments, it is also possible to use other types of batteries. In addition, the threshold value to which the battery voltage and the resistance voltage are compared is not limited to the values mentioned in the above description. Rather, the threshold may be appropriately determined according to various conditions such as specifications of the battery used in the battery pack.

The abnormality diagnosis apparatus according to the illustrated embodiment of the present invention may be applied to a system using a battery. For example, the fault diagnosis apparatus according to the illustrated embodiment of the present invention may be employed in a system other than a hybrid vehicle, an electric vehicle, a fuel cell vehicle, or a vehicle using a battery.

Therefore, according to the abnormality diagnosis apparatus according to the present invention, voltage abnormality of the batteries C1 to Cn, disconnection of the electrical connection, and switching abnormality of the switches SW1 to SWn can be detected and confirmed.

General interpretation of the term

In the understanding of the scope of the present invention, "comprising" and its derivatives, as used herein, refers to the presence of the described features, elements, components, groups, integers and / or steps, but not described otherwise. It is intended to be an open ended term that does not exclude the presence of features, elements, components, groups, integers and / or steps. This also applies to words of similar meaning, such as "having", "having", and derivatives thereof. In addition, the terms "part", "section", "part", and "member" when used in the singular may have the dual meaning of a single part or a plurality of parts. As used herein, the term "detection" used to describe an operation or function performed by a component, section, apparatus, or the like, does not require physical detection, but determination, measurement, modeling, prediction or computing, etc., to perform the operation or function. Includes components, sections, devices, and the like that include. The term "configured", as used herein to describe components, sections, or parts of an apparatus, includes hardware and / or software that is configured and / or programmed to perform an operation or function.

While only selected embodiments have been selected to illustrate the invention, those skilled in the art will recognize that various changes and modifications may be made within the scope of the invention as defined in the claims. For example, the size, shape, installation or orientation of the various components can be changed as needed. Components shown to be in contact with or directly connected to each other may have intermediate structures disposed therebetween. The function of an element can be performed in two ways and vice versa. The structure and function of one embodiment may be adopted in another embodiment. Not all advantages need to be present in a particular embodiment at the same time. All features that do not exist in the prior art, alone or in combination with other features, should be considered as a separate description of the additional invention by the applicant, including structural and / or functional concepts implemented by such feature (s). . Accordingly, it is to be understood that the foregoing descriptions of the embodiments according to the present invention are provided by way of example only, and are not intended to limit the invention as defined by the claims and their equivalents.

1 is a schematic diagram of a battery pack provided with a fault diagnosis apparatus according to a first embodiment of the present invention.

Fig. 2 is a flowchart showing a diagnostic process performed by the abnormality diagnosis apparatus according to the first embodiment of the present invention.

Fig. 3 is a schematic diagram of a battery pack provided with a fault diagnosis apparatus according to a first embodiment of the present invention, showing a case where the entire switch of the fault diagnosis apparatus is turned on and there is a disconnection in a line connected to the positive electrode of the highest battery of the battery pack.

Fig. 4 is a schematic diagram of a battery pack provided with an abnormality diagnosing device according to the first embodiment of the present invention, showing a case where the entire switch is turned on and there is a disconnection in a line connected to a terminal of a battery other than the top battery of the battery pack.

Fig. 5 is provided with an abnormality diagnosing apparatus according to the first embodiment of the present invention, showing a case where one of the switches has an abnormality so that the switch remains off even when an on-signal is transmitted from the abnormality diagnosing section of the abnormality diagnosing apparatus. Schematic diagram of the battery pack.

Fig. 6 is an illustration of a table summarizing a method of distinguishing different types of abnormalities based on control states of a switch, a resistance voltage, and a battery voltage, according to the first embodiment of the present invention.

7 is a schematic diagram of a battery pack provided with a fault diagnosis apparatus according to a second embodiment of the present invention in which a switch voltage detection circuit is provided for detecting a voltage applied to a switch.

Fig. 8 is a flowchart showing diagnostic processing performed by the abnormality diagnosing apparatus according to the second embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1: battery pack

10: abnormal diagnosis section

R1 to Rn: resistance

C1 to Cn: battery

SW1 to SWn: switch

L0 to Ln: line

B1 to Bn: resistance voltage detection circuit

D1 to Dn: battery voltage detection circuit

E1 to En: switch voltage detection circuit

Claims (20)

An abnormality diagnosis device for diagnosing an abnormality in a battery pack having a plurality of cells connected in series, A plurality of battery voltage detection circuits each of which is connected in parallel to a corresponding one of the cells of the battery pack to detect the voltage of the battery; A plurality of discharge circuits each of which has a switch and a resistor connected in parallel to a corresponding one of the cells, each of which is connected in series; A switch driving circuit connected to the switch of the discharge circuit, A plurality of diagnostic voltage detection circuits each of which is electrically connected to a corresponding one of the discharge circuits to detect a voltage across a corresponding one of the switches and a voltage across a corresponding one of the resistors, and Includes a fault diagnosis control section, The abnormal diagnostic control section controls the switch driving circuit to perform a first diagnostic operation in which switches corresponding to every other battery are turned on and a second diagnostic operation in which all switches are turned on, Whether the voltage detected by the diagnostic voltage detecting circuit during the first diagnostic operation is an abnormal voltage or a normal voltage, whether the voltage detected by the diagnostic voltage detecting circuit during the second diagnostic operation is an abnormal voltage or a normal voltage and the battery On the basis of whether the voltage detected by the voltage detection circuit is an abnormal voltage or a normal voltage and a combination of these abnormal voltages or normal voltages, there is a disconnection or a switch in the electrical connection between the one battery and the corresponding discharge circuit. An abnormality diagnosis apparatus configured to determine whether one of the abnormalities is present. The circuit of claim 1, wherein each of the diagnostic voltage detection circuits is configured to detect a voltage across a corresponding resistor, The abnormal diagnostic control section further Control the switch drive circuit to turn on a switch corresponding to an odd number of cells counted from the highest order battery during the first diagnostic operation, One of the voltages detected by the diagnostic voltage detection circuit during the first diagnostic operation is abnormal and one of the voltages detected by the diagnostic voltage detection circuit during the second diagnostic operation is abnormal and of the voltages detected by the battery voltage detection circuit. When one is abnormal, it determines that there is a break in the electrical connection, When one of the voltages detected by the diagnostic voltage detection circuit is abnormal during the first diagnostic operation and one of the voltages detected by the diagnostic voltage detection circuit during the second diagnostic operation is both abnormal and detected by the battery voltage detection circuit. Is configured to determine that an abnormality is present in one of the switches when is normal. The circuit of claim 1, wherein each of the diagnostic voltage detection circuits is configured to detect a voltage across a corresponding resistor, The abnormal diagnostic control section further Control the switch drive circuit to turn on a switch corresponding to an odd number of cells counted from the highest order battery during the first diagnostic operation, When one of the voltages detected by the diagnostic voltage detection circuit during the first diagnostic operation is abnormal and all of the voltages detected by the diagnostic voltage detection circuit during the second diagnostic operation are normal and all of the voltages detected by the battery voltage detection circuit are And an abnormality diagnosis device configured to determine that a disconnection exists in the electrical connection when it is normal. The circuit of claim 1, wherein each of the diagnostic voltage detection circuits is configured to detect a voltage across a corresponding resistor, The abnormal diagnostic control section further Control the switch drive circuit to turn on a switch corresponding to an odd number of cells counted from the highest order battery during the first diagnostic operation, Controlling the switch driving circuit to perform a third diagnostic operation in which a switch corresponding to an even numbered battery of the cells is turned on, Determining that an abnormality exists in one of the switches when all of the voltages detected by the diagnostic voltage detection circuit during the first diagnostic operation are normal and when one of the voltages detected by the diagnostic voltage detection circuit is abnormal during the third diagnostic operation, And an abnormality diagnosis apparatus configured to determine that there is no abnormality in the switch and no disconnection in the electrical connection when both of the voltages detected by the diagnostic voltage detecting circuit during the first and third diagnostic operations are normal. The circuit of claim 1, wherein each of the diagnostic voltage detection circuits is configured to detect a voltage across a corresponding switch, The abnormal diagnostic control section further Control the switch driving circuit to turn on a switch corresponding to an even numbered battery among the cells counted from the highest order battery during the first diagnostic operation, Determination that an abnormality exists in one of the switches when one of the voltages detected by the diagnostic voltage detection circuit is abnormal during the first diagnostic operation and one of the voltages detected by the diagnostic voltage detection circuit during the second diagnostic operation is abnormal. , One of the voltages detected by the battery voltage detection circuit when both of the voltages detected by the diagnostic voltage detection circuit during the first diagnostic operation are abnormal and during the second diagnostic operation are all normal and detected by the battery voltage detection circuit. And an abnormality diagnosis device configured to determine that a disconnection exists in the electrical connection when is abnormal. The circuit of claim 1, wherein each of the diagnostic voltage detection circuits is configured to detect a voltage across a corresponding switch, The abnormal diagnostic control section further Control the switch driving circuit to turn on a switch corresponding to an even numbered battery among the cells counted from the highest order battery during the first diagnostic operation, Control the switch drive circuit to perform a third diagnostic operation in which all switches are turned off, When one of the voltages detected by the diagnostic voltage detection circuit during the first diagnostic operation is abnormal, all of the voltages detected by the diagnostic voltage detection circuit during the second diagnostic operation are normal and all of the voltages detected by the battery voltage detection circuit are Determine that there is an abnormality in one of the switches when both normal and the voltage detected by the battery voltage detection circuit during the third diagnostic operation is normal, When one of the voltages detected by the diagnostic voltage detection circuit during the first diagnostic operation is abnormal, all of the voltages detected by the diagnostic voltage detection circuit during the second diagnostic operation are normal and all of the voltages detected by the battery voltage detection circuit are And an abnormality diagnosis device configured to determine that there is a disconnection in the electrical connection when it is normal and when one of the voltages detected by the battery voltage detection circuit during the third diagnostic operation is abnormal. The circuit of claim 1, wherein each of the diagnostic voltage detection circuits is configured to detect a voltage across a corresponding switch, The abnormal diagnostic control section further Control the switch driving circuit to turn on a switch corresponding to an even numbered battery among the cells counted from the highest order battery during the first diagnostic operation, Configured to determine that an abnormality exists in one of the switches when all of the voltages detected by the diagnostic voltage detection circuit during the first diagnostic operation are normal and when one of the voltages detected by the diagnostic voltage detection circuit is abnormal during the second diagnostic operation. Abnormal diagnostic device. The circuit of claim 1, wherein each of the diagnostic voltage detection circuits is configured to detect a voltage across a corresponding switch, The abnormal diagnostic control section further Control the switch driving circuit to turn on a switch corresponding to an even numbered battery among the cells counted from the highest order battery during the first diagnostic operation, Control the switch drive circuit to perform a third diagnostic operation in which all switches are turned off, When all of the voltages detected by the diagnostic voltage detection circuit during the first diagnostic operation are normal, when all of the voltages detected by the diagnostic voltage detection circuit during the second diagnostic operation are normal, and by the diagnostic voltage detection circuit during the third diagnostic operation. It is determined that an abnormality exists in one of the switches when one of the detected voltages is abnormal, When both the voltage detected by the diagnostic voltage detection circuit and the voltage detected by the battery voltage detection circuit are normal during the first, second and third diagnostic operations, determine that there is no abnormality in the switch and no disconnection in the electrical connection. Abnormal diagnosis device configured. An error diagnosis method for diagnosing an abnormality in a battery pack having a plurality of cells connected in series. Providing a plurality of discharge circuits each of which is connected in parallel to a corresponding one of the cells of the battery pack, each discharge circuit having a switch and a resistor connected in series; Performing a first diagnostic operation to turn on a switch corresponding to every other battery, Performing a second diagnostic operation to turn on all switches, Detecting a battery voltage of a battery of the battery pack, Detecting a discharge circuit voltage having one of a voltage across each of said switches and a voltage across each of said resistors, and Whether the discharge circuit voltage and the battery voltage detected during the first diagnostic operation are abnormal voltages or normal voltages, and whether the discharge circuit voltage and the battery voltage detected during the second diagnostic operation are abnormal voltages or normal voltages, and their abnormalities. And determining, based on a combination of voltages or normal voltages, whether there is a break in the electrical connection between the one battery and the corresponding discharge circuit or whether there is an abnormality in one of the switches. 10. The method of claim 9, wherein detecting the discharge circuit voltage comprises detecting a voltage across each resistor, The performing of the first diagnostic operation includes turning on a switch corresponding to an odd number of cells counted from the highest order battery. The method of claim 10, wherein determining whether there is a disconnect in the electrical connection or an abnormality in one of the switches comprises: Determining that a disconnection exists in the electrical connection when one of the discharge circuit voltages is abnormal during the first diagnostic operation and one of the discharge circuit voltages is abnormal and one of the battery voltages is abnormal during the second diagnostic operation, and Determining an abnormality in one of the switches when one of the discharge circuit voltages is abnormal during the first diagnostic operation and when one of the discharge circuit voltages is abnormal and all of the battery voltages are normal during the second diagnostic operation. . The method of claim 10, wherein determining whether there is a disconnect in the electrical connection or an abnormality in one of the switches comprises: And determining that there is a disconnection in the electrical connection when one of the discharge circuit voltages is abnormal during the first diagnostic operation and both of the discharge circuit voltages are normal during the second diagnostic operation and all of the battery voltages are normal. 11. The method of claim 10, further comprising performing a third diagnostic operation to turn on a switch corresponding to an even numbered battery among the cells. The method of claim 13, wherein determining whether there is a disconnect in the electrical connection or an abnormality in one of the switches comprises: Determining that one of the switches is abnormal when both of the discharge circuit voltages are normal during the first diagnostic operation and when one of the discharge circuit voltages is abnormal during the third diagnostic operation, and And determining that there is no abnormality in the switch and no disconnection in the electrical connection when both of the discharge circuit voltages are normal during the first and third diagnostic operations. 10. The method of claim 9, wherein detecting the discharge circuit voltage comprises detecting a voltage across each switch, The performing of the first diagnostic operation includes turning on a switch corresponding to an even-numbered battery among cells counted from the highest battery. The method of claim 15, wherein determining whether there is a disconnect in the electrical connection or an abnormality in one of the switches comprises: Determining that one of the switches is abnormal when one of the discharge circuit voltages is abnormal during the first diagnostic operation and one of the discharge circuit voltages is abnormal during the second diagnostic operation, and And determining that there is a disconnection in the electrical connection when one of the discharge circuit voltages is abnormal during the first diagnostic operation and both of the discharge circuit voltages are normal during the second diagnostic operation and one of the battery voltages is abnormal. . 16. The method of claim 15, further comprising performing a third diagnostic operation to turn off all of the switches. The method of claim 17, wherein determining whether there is a disconnect in the electrical connection or an abnormality in one of the switches comprises: When one of the discharge circuit voltages is abnormal during the first diagnostic operation, when both the discharge circuit voltages are normal and all the battery voltages are normal during the second diagnostic operation, and when all of the battery voltages are normal during the third diagnostic operation, Determining that there is an abnormality, and Electrical connection when one of the discharge circuit voltages is abnormal during the first diagnostic operation, all of the discharge circuit voltages are normal and all of the battery voltages are normal during the second diagnostic operation, and when one of the battery voltages is abnormal during the third diagnostic operation. And determining that there is a disconnection. The method of claim 15, wherein determining whether there is a disconnect in the electrical connection or an abnormality in one of the switches comprises: And determining that there is an error in one of the switches when both of the discharge circuit voltages are normal during the first diagnostic operation and when one of the discharge circuit voltages is abnormal during the second diagnostic operation. The method of claim 17, wherein determining whether there is a disconnect in the electrical connection or an abnormality in one of the switches comprises: Determining that one of the switches is abnormal when all of the discharge circuit voltages are normal during the first diagnostic operation, when all of the discharge circuit voltages are normal during the second diagnostic operation, and when one of the discharge circuit voltages is abnormal during the third diagnostic operation. Steps, and And determining that there is no abnormality in the switch and no disconnection in the electrical connection when all the discharge circuit voltages and all the battery voltages are normal during the first, second and third diagnostic operations.

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