JP5239975B2 - Earth leakage detection system - Google Patents

Description

  The present invention is an apparatus for detecting leakage from an assembled battery, which is a battery cell series connection body, to a vehicle body, and outputs an AC signal to the assembled battery via a capacitor and a resistor. And a leakage detection system including a leakage detection means for detecting the presence or absence of the leakage based on a potential between the capacitor and the resistor.

  For example, in a hybrid vehicle, an electric vehicle, a fuel cell vehicle, and the like, it is common to use an assembled battery as a series connection body of a plurality of battery cells while being insulated from the vehicle body. For these battery cells, various monitoring devices for monitoring the state have been proposed and partially put into practical use. As such a monitoring device, for example, as described in Patent Document 1 below, a multiplexer that selectively connects a plurality of battery cells to a flying capacitor and a switching element that connects the flying capacitor to a voltage detection circuit are provided. There are also things. As a result, the voltage of the both ends of the flying capacitor is detected by the voltage detection circuit in a state where the electrical connection between the battery cell and the flying capacitor is cut off, thereby detecting the voltage of the battery cell while insulating the assembled battery from the vehicle. can do.

  Further, as seen in, for example, Patent Document 2 below, a leakage detection device that detects a leakage from the assembled battery to the vehicle body has been proposed and put into practical use. This leakage detection device outputs an alternating current signal to an assembled battery via a capacitor and a resistor, and detects the presence or absence of a leakage based on the potential between the capacitor and the resistor. That is, when the assembled battery and the vehicle are short-circuited, the AC signal is divided by the resistance between the vehicle and the assembled battery and the resistor, so that the peak value decreases. For this reason, it is possible to detect a leakage based on a decrease in potential between the capacitor and the resistor.

  Furthermore, this document includes a circuit for intentionally short-circuiting the assembled battery to the vehicle body, and judges whether there is an abnormality in the leakage detection device based on the potential between the capacitor and the resistor in a state where the assembled battery is intentionally short-circuited. Has also been proposed.

Japanese Patent No. 3572183 JP-A-10-221395

  By the way, providing the circuit which short-circuits an assembled battery and a vehicle body for the purpose of detecting the presence or absence of an abnormality in the leakage detection device as described above causes an increase in the number of parts. In particular, such a circuit is generally configured to include an insulating element such as a photo MOS relay. In this case, however, the cost increases significantly. Furthermore, since the circuit for short-circuiting includes components of a high-voltage system that is insulated from the vehicle body, there may be a restriction on the arrangement.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide an AC signal output means for outputting an AC signal to a battery pack via a capacitor and a resistor, and a potential between the capacitor and the resistor. The present invention is to provide a leakage detection system capable of determining whether or not there is an abnormality in a leakage detection device comprising a leakage detection means for detecting the presence or absence of leakage based on the above while suppressing an increase in the number of parts.

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

  The invention according to claim 1 is a device for detecting an electric leakage from the assembled battery, which is a series connection body of battery cells, to the vehicle body, and outputs an AC signal to the assembled battery via a capacitor and a resistor. A leakage detection device comprising an AC signal output means, a leakage detection means for detecting the presence or absence of the leakage based on the potential between the capacitor and the resistor, and one or a plurality of adjacent battery cells constituting the assembled battery An apparatus for detecting a voltage of a unit battery, and a power storage means, a voltage detection means, a high voltage side opening / closing means for electrically opening and closing between the unit battery and the power storage means, the power storage means, and the A voltage detection device comprising a low voltage side switching means for electrically opening and closing between the voltage detection means, an operation means for closing both the low voltage side switching means and the high voltage side switching means, and the AC signal output. Determining means for determining whether or not the leakage detecting device is abnormal based on a potential between the capacitor and the resistor when the AC signal is output by the means and the both are closed by the operating means. It is characterized by that.

  According to the voltage detection device, the voltage of the unit battery can be detected while insulating the assembled battery and the vehicle body by alternately closing the low voltage side opening / closing means and the high voltage side opening / closing means. On the other hand, when the AC signal is output, the potential between the capacitor and the resistor changes according to the presence or absence of leakage from the assembled battery to the vehicle body. For this reason, in the said leakage detection apparatus, the electric leakage from an assembled battery to a vehicle body can be detected because the electric potential between a capacitor and a resistor becomes low.

  In addition, it is possible to intentionally electrically connect the assembled battery and the vehicle body by closing both the low voltage side opening / closing means and the high voltage side opening / closing means. For this reason, based on the electric potential between the capacitor and the resistor at this time, it is possible to determine whether or not the leakage detecting device is abnormal.

According to a second aspect of the present invention, in the first aspect of the invention, the low voltage side opening / closing means and the high voltage side opening / closing means each include a plurality of opening / closing means. and having a function of different combinations of opening and closing means the last closing operation of the combination of the opening and closing means for closing operation.

In the above invention, by providing a function of different combinations of opening and closing means the last closing operation of the combination of the opening and closing means for closing operation when the both turned on, the resistance value at the time of electrical connection between the battery pack and the vehicle body intentionally Can be variably set, and the presence / absence of abnormality of the opening / closing means can be determined.

According to a third aspect of the present invention, in the first or second aspect of the invention, each of the low-voltage side opening / closing means and the high-voltage side opening / closing means includes a plurality of opening / closing means, and the operation means is configured to turn on both of them. It is characterized in that it has a function of making the number of opening / closing means that are closed during operation differ from the number of opening / closing means that were closed last time .

In the above invention, the resistance value when the assembled battery and the vehicle body are intentionally electrically connected is provided with a function of making the number of the opening / closing means to be closed at the time of the both ON operations differ from the number of the opening / closing means having been previously closed. Can be variably set, and the presence / absence of abnormality of the opening / closing means can be determined.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the voltage detection means includes an input terminal connected to the power storage means, and the input terminal is a resistor. It is connected to the vehicle body through a body.

  In the above invention, by connecting the input terminal to the vehicle body via a resistor, it is possible to suppress the influence of noise or suppress the oscillation phenomenon when detecting voltage. In addition, by closing both the high-voltage side opening / closing means and the low-voltage side opening / closing means, the vehicle body and the assembled battery can be electrically connected using this resistor.

The system configuration figure of a 1st embodiment. The time chart which shows the abnormality determination process aspect of the leak detection apparatus concerning the embodiment. The flowchart which shows the procedure of the abnormality determination process of the leak detection apparatus concerning the embodiment. The flowchart which shows the procedure of the abnormality determination process of the leak detection apparatus concerning 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment in which a leakage detection system according to the present invention is applied to a hybrid vehicle will be described with reference to the drawings.

  FIG. 1 shows the system configuration of this embodiment. The illustrated assembled battery 10 constitutes a vehicle-mounted high-voltage battery, supplies power to the vehicle-mounted rotating machine, charges electric energy supplied from the vehicle-mounted rotating machine, and further includes a step-down converter (not illustrated). Power is supplied to the vehicle-mounted low-voltage battery. The assembled battery 10 is a serially connected body of battery cells 12 made of a lithium ion secondary battery. Specifically, the assembled battery 10 is grouped into a predetermined number of adjacent battery cells 12 to constitute a block Bi (i = 0 to 3).

  A wiring Li is connected to the negative terminal of each block Bi constituting the assembled battery 10, and a wiring L (i + 1) is connected to the positive terminal of each block Bi. Each wiring Lj (j = 0 to 4) includes a resistor 14, and is connected to the multiplexer MPX at the other end of the resistor 14.

  The multiplexer MPX selectively connects the pair of wirings Li and L (i + 1) to the flying capacitor 16. Specifically, the multiplexer MPX connects the pair of wirings Li and L (i + 1) to the flying capacitor 16 in such a manner that the charging polarities when the voltages of adjacent blocks are applied to the flying capacitor 16 are opposite to each other. The multiplexer MPX includes a high-voltage side switching element SWj corresponding to each wiring Lj, and the high-voltage side switching elements SW0, SW2, SW4 and the high-voltage side switching elements SW1, SW3 are different from each other in the flying capacitor 16. Connected to the electrode. Note that the high-voltage side switching elements SW0 to SW4 are configured by an insulating element such as a photo MOS relay, for example.

  The flying capacitor 16 can be connected to the voltage detection circuit 20 via the low-voltage side switching elements SSa and SSb. The voltage detection circuit 20 includes a differential amplifier circuit configured using an operational amplifier 21. That is, the inverting input terminal of the operational amplifier 21 is connected to the low voltage side switching element SSa via the resistor 22, and the non-inverting input terminal is connected to the low voltage side switching element SSb via the resistor 23. Further, the inverting input terminal and the output terminal are connected by a resistor 24. A power supply 26 is connected to the non-inverting input terminal of the operational amplifier 21 through a resistor 25. This is for fixing the polarity of the output voltage of the voltage detection circuit 20 regardless of the charging voltage of the flying capacitor 16. The output terminal is grounded via a resistor 27. This is intended to suppress noise and suppression of resonance phenomenon. The low-voltage side switching elements SSa and SSb are composed of insulating elements such as photo MOS relays.

  The flying capacitor 16 is electrically connected to the voltage detection circuit 20 via the low-voltage side switching elements SSa and SSb, so that the voltage of the flying capacitor 16 is detected by the voltage detection circuit 20. The output signal of the voltage detection circuit 20 is taken into the battery pack electronic control device (battery ECU 30). The battery ECU 30 includes an analog-digital conversion device (A / D conversion device 32), and thereby converts the output voltage of the voltage detection circuit 20 into digital data. The control unit 34 performs various digital processes based on the digital data output from the A / D conversion device 32.

  Further, the control unit 34 detects the voltage of the block Bi by operating the multiplexer MPX and the low-voltage side switching elements SSa and SSb. That is, when detecting the voltage of the block Bi, the low-voltage side switching elements SSa and SSb are turned off and the high-voltage side switching elements SWi and SW (i + 1) are turned on for a predetermined time (for example, “several ms”). Thus, the voltage of the block Bi is applied to the flying capacitor 16. Then, after the block Bi and the flying capacitor 16 are insulated, the low voltage side switching elements SSa and SSb are turned on to apply the voltage of the flying capacitor 16 to the voltage detection circuit 20. Thereby, the battery ECU 30 can detect the voltage of each block Bi.

  Further, the battery ECU 30 performs a process for detecting the presence or absence of insulation failure between the vehicle-mounted high-voltage system including the assembled battery 10 and the vehicle body. This is a process corresponding to the regulation that the high pressure system must be insulated from the vehicle body. The ground line for the battery ECU 30 is the vehicle body.

  In order to execute such processing, the control unit 34 outputs a rectangular wave AC signal (rectangular wave signal RS). The rectangular wave signal RS has a period of, for example, about “several hundred ms”. The rectangular wave signal RS is taken into a voltage follower 36 as impedance conversion means. The output of the voltage follower 36 is electrically connected to the assembled battery 10 via the resistor 38 and the capacitor 48. Specifically, in the present embodiment, the battery pack 10 is connected to the wiring L0 on the positive electrode side of the assembled battery 10. On the other hand, the connection point between the resistor 38 and the capacitor 48 is applied to the inverting input terminal of the comparator 40, and the threshold voltage Vth is applied to the non-inverting input terminal of the comparator 40. Here, the threshold voltage Vth is generated by dividing the voltage of the power source 42 by the resistors 44 and 46. The output of the comparator 40 (diagnosis signal DS) is taken into the control unit 34. In the control part 34, the presence or absence of the insulation defect of a high voltage | pressure system and a vehicle body is judged based on the output of the comparator 40 at the time of outputting the rectangular wave signal RS.

  That is, when the insulation between the high-voltage system and the vehicle body is good, the potential Va at the inverting input terminal of the comparator 40, in other words, the potential Va between the resistor 38 and the capacitor 48 is a rectangular wave output by the control unit 34. It becomes the signal RS itself. On the other hand, when the insulation between the high voltage system and the vehicle body is insufficient, a closed loop circuit including the vehicle body, the resistor 38, the capacitor 48, and the high voltage system is formed. The potential Va decreases. Therefore, by setting the threshold voltage Vth to a value that can determine the change in the potential Va due to the presence or absence of these insulation defects, it is possible to determine the presence or absence of insulation defects between the high-voltage system and the vehicle body.

  In the present embodiment, the assembled battery 10 and the voltage detection circuit 20 are intentionally short-circuited using a voltage detection device configured to include the voltage detection circuit 20, and based on the diagnostic signal DS at that time, Determine if there is an abnormality in the leakage detection device. This will be described in detail below.

  FIG. 2 shows an aspect of the leakage detection process and the diagnosis process of whether there is an abnormality in the leakage detection device according to the present embodiment. Specifically, FIG. 2A shows the transition of the rectangular wave signal RS, FIG. 2B shows the transition of the potential Va between the resistor 38 and the capacitor 48, and FIG. 2C shows the diagnostic signal. FIG. 2D shows the transition of the operation mode of the multiplexer MPX, and FIG. 2E shows the transition of the operation mode of the low-voltage side switching elements SSa and SSb.

  As shown in the figure, during the period from time t1 to time t2, leakage detection processing is performed. Here, it can be determined that the diagnostic signal DS rises at the rising edge of the rectangular wave signal RS and is normal. Further, in the leakage detection processing period, the multiplexer MPX and the low-voltage side switching elements SSa and SSb are alternately turned on, so that the charging processing of the flying capacitor 16 by the block Bi and the flying capacitor 16 by the voltage detection circuit 20 are performed. A charging voltage detection process is performed. Note that the period of the rectangular wave signal RS is longer than the on-operation period of the multiplexer MPX, which is the charging period of the flying capacitor 16. This corresponds to the capacitance of the capacitor 48 being larger than the capacitance of the flying capacitor 16.

  On the other hand, after time t2, it is determined whether or not the leakage detection device is abnormal. Here, both the multiplexer MPX and the low-voltage side switching elements SSa and SSb are turned on to generate an intentional leakage state of the assembled battery 10. At this time, the potential Va is lowered, and the diagnosis signal DS is always logic “L”, so that it is possible to determine that the leakage detecting device is normal.

  FIG. 3 shows the procedure of the leakage detection process and the determination process of whether there is an abnormality in the leakage detection apparatus according to the present embodiment. This process is repeatedly executed by the battery ECU 30, for example, at a predetermined cycle.

  In this series of processes, first, in step S10, it is determined whether or not the start switch of the vehicle is on. Here, the activation switch is a switch for activating the vehicle control system and can be operated by the user. The operation by the user does not necessarily mean that the user manually operates, and includes, for example, that the user brings a portable wireless transmitter that outputs a predetermined wireless signal close to the vehicle.

  When a positive determination is made in step S10, the rectangular wave signal RS is output from the control unit 34 in step S12. In a succeeding step S14, it is determined whether or not an abnormality diagnosis condition is satisfied. This condition may be, for example, immediately after the start switch is turned on, or when a predetermined time has elapsed since the vehicle was stopped and the previous abnormality diagnosis was executed. If it is determined that the abnormality diagnosis condition is not satisfied, the leakage detection process described above is performed in step S16.

  On the other hand, when it is determined that the abnormality diagnosis condition is satisfied, a short circuit that intentionally short-circuits the assembled battery 10 and the voltage detection circuit 20 using the voltage detection device including the voltage detection circuit 20 in step S18. Process. Specifically, any one of the high-voltage side switching elements SW0, SW2, and SW4 and the low-voltage side switching element Sa, and any one of the high-voltage side switching elements SW1 and SW3 and the low-voltage side switching element Sb are turned on. Thereby, the assembled battery 10 is grounded via the resistors 22, 24, 27 or the resistors 24, 25 and the power supply 26.

  In the subsequent step S20, the process waits for a predetermined time. This process is for determining whether or not the leakage detection device is abnormal after the capacitor 48 is charged. That is, whether or not the leakage detecting device is abnormal is determined by dividing the rectangular wave signal RS by the resistor 38 and the resistors 22, 24, 27 or the resistors 24, 25. The fact that the potential Va between them is lower than the potential at the connection point of the resistors 44 and 46 is utilized. On the other hand, when the assembled battery 10 is grounded, the capacitor 48 is charged to a charging voltage equal to the difference between the potential at the connection location of the assembled battery 10 and the potential Va between the resistor 38 and the capacitor 48. Then, when the capacitor 48 becomes this charging voltage, the rectangular wave signal RS is divided by the resistor 38 and the resistors 22, 24, 27 or the resistors 24, 25. For this reason, before the voltage of the capacitor | condenser 48 becomes steady, determination of the presence or absence of abnormality cannot be performed appropriately.

  Then, since it is considered that the voltage of the capacitor 48 has become steady after a predetermined time has elapsed, it is determined in step S22 whether or not the diagnostic signal DS is always logic L. If the diagnosis signal DS is always logic L, it is determined that the signal is normal in step S24. On the other hand, when a negative determination is made in step S22, it is determined that there is an abnormality in step S26.

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

  (1) The leakage state of the assembled battery 10 was intentionally generated by turning on both the multiplexer MPX and the low-voltage side switching elements SSa and SSb. As a result, it is possible to determine whether there is an abnormality in the leakage detection device using the voltage detection means of the block Bi, and thus it is possible to determine whether there is an abnormality while suppressing an increase in the number of parts.

  (2) The output terminal of the operational amplifier 21 is grounded through the resistor 27. Thereby, it is possible to suppress the influence of noise and resonance phenomenon when detecting voltage. Furthermore, by this, both the assembled battery 10 and the vehicle body can be connected by turning on both the multiplexer MPX and the low-voltage side switching element SSa.

  (3) The non-inverting input terminal of the operational amplifier 21 is grounded via the resistor 25 and the power source 26. Thereby, although the charging polarity of the flying capacitor 16 is inverted, the polarity of the output of the voltage detection circuit 20 can be fixed. Furthermore, the assembled battery 10 and the vehicle body can be connected by turning on both the multiplexer MPX and the low-voltage side switching element SSb.

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

  FIG. 4 shows the procedure of the leakage detection process and the determination process of whether there is an abnormality in the leakage detection apparatus according to the present embodiment. This process is repeatedly executed by the battery ECU 30, for example, at a predetermined cycle. In FIG. 4, processes corresponding to the processes shown in FIG. 3 are given the same step numbers for convenience.

  In this series of processes, when it is determined in step S14 that the abnormality diagnosis condition has been established, instead of the short-circuit process in step S18, in step S18a, the assembled battery 10 is intentionally connected to the vehicle body and connected. An impedance variable process for changing the impedance of the path is performed. Specifically, any one of the high-voltage side switching elements SW0, SW2, and SW4 and the low-voltage side switching element Sa, and any one of the high-voltage side switching elements SW1 and SW3 and the low-voltage side switching element Sb are turned on. A process of switching between the state in which both are turned on is performed.

  Specifically, this switching process is performed after it is determined that the duration of the short circuit process has reached a predetermined time (step S20: YES). In step S22a, it is determined whether or not the potential Va between the resistor 38 and the capacitor 48 is increased by increasing the impedance of the connection path between the assembled battery 10 and the vehicle body. In making this determination, the system shown in FIG. 1 is changed so that the control unit 34 has a function of monitoring the potential Va.

  The process of step S22a is for determining whether or not the leakage detecting device is abnormal. That is, when the assembled battery 10 and the vehicle body are connected, the rectangular wave signal RS that appears between the resistor 38 and the capacitor 48 is the resistance of the rectangular wave signal RS output from the control unit 34 to the resistor 38 and the connection path. The pressure is divided by the body. For this reason, as the resistance value of the resistor in the connection path increases, the potential Va at the time of logic “H” of the rectangular wave signal RS increases.

  If an affirmative determination is made in step S22a, it is determined to be normal in step S24, and if a negative determination is made, it is determined to be abnormal in step S26.

  According to the embodiment described above in detail, the following effects can be obtained in addition to the effects (2) and (3) of the first embodiment.

  (4) When both the multiplexer MPX and the low-voltage side switching elements SSa and SSb are turned on, the operation mode is changed to make the resistance value of the connection path between the assembled battery 10 and the vehicle body variable. As a result, it is possible to determine whether there is an abnormality in the leakage detection device using the voltage detection means of the block Bi, and thus it is possible to determine whether there is an abnormality in the leakage detection device while suppressing an increase in the number of parts. .

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

  In the first embodiment, any one of the high-voltage side switching elements SW0, SW2, and SW4 and the low-voltage side switching element Sa, and any one of the high-voltage side switching elements SW1 and SW3 and the low-voltage side switching element Sb. Although the presence / absence of abnormality is determined by turning on the pair, the present invention is not limited to this. For example, it is determined whether there is an abnormality by turning on all of the high-voltage side switching elements SW0, SW2, and SW4 and the low-voltage side switching element Sa, or turning on all of the high-voltage side switching elements SW1 and SW3 and the low-voltage side switching element Sb. The presence or absence of abnormality may be judged.

  In the first embodiment, three patterns for turning on one of the high-voltage side switching elements SW0, SW2, and SW4 and the low-voltage side switching element Sa, one of the high-voltage side switching elements SW1 and SW3, and the low-voltage side switching element You may perform the process which judges the presence or absence of abnormality in each of a total of 5 patterns with 2 patterns which turn ON Sb. In this case, if there is a pattern that is determined to be normal in at least one pattern and there is a pattern that is determined to be abnormal, it may be determined that the switching element used for the abnormality determination is abnormally stuck. . Thereby, it is also possible to determine whether the switching element is stuck open.

  In the first embodiment, any one of the high-voltage side switching elements SW0, SW2, and SW4 and the low-voltage side switching element Sa, and any one of the high-voltage side switching elements SW1 and SW3 and the low-voltage side switching element Sb. Although the presence / absence of abnormality is determined by turning on the pair, the present invention is not limited to this. For example, a diagnostic signal when any one of the high-voltage side switching elements SW0, SW2, and SW4 and the low-voltage side switching element Sa and the high-voltage side switching elements SW1 and SW3 and the low-voltage side switching element Sb are turned on. The presence or absence of an abnormality may be determined based on the DS. The point is that the switching operation can realize a connection state that approximates this resistance value depending on whether the connection state between the assembled battery 10 to be detected and the vehicle body has a low resistance value.

  In the second embodiment, any one of the high-voltage side switching elements SW0, SW2, and SW4 and the low-voltage side switching element Sa, and any one of the high-voltage side switching elements SW1 and SW3 and the low-voltage side switching element Sb. Although it is determined that an abnormality occurs when the crest value of the potential Va does not decrease when both are turned on rather than when the pair is turned on, the present invention is not limited to this. For example, in the configuration of FIG. 1, the determination of the presence / absence of an abnormality based on the diagnostic signal DS when any one of the above sets is turned on and the determination of the presence / absence of an abnormality based on the diagnostic signal DS when both are turned on are performed. It may be performed at different timings.

  The number of flying capacitors 16 and voltage detection circuits 20 is not limited to one, and a plurality of these may be provided. In this case, since the number of connection paths with the vehicle body via the low-voltage switching elements that are different from each other increases, the resistance value of the connection path with the vehicle body can be made more multi-stage. For this reason, it is also possible to determine that the abnormality is based on the fact that the potential Va decreases as the resistance value decreases, using the electrical connection state of these resistance values, as in the second embodiment.

  The voltage detection circuit 20 is not limited to that illustrated in FIG. For example, if the resistance value between the inverting input terminal or the non-inverting input terminal of the operational amplifier and the ground is approximate to the resistance value of the connection state between the assembled battery 10 to be detected and the vehicle body, the resistor 27, Even if it does not have 24 etc., the said connection state of the assembled battery 10 and a vehicle body is detectable.

  -Abnormality diagnosis conditions for the leakage detection device are not limited to those exemplified in the above embodiments. For example, it may be performed while the vehicle is running.

  -The AC signal is not limited to a rectangular wave signal. For example, it may be a sine wave signal. Thereby, it is possible to avoid the generation of high-order harmonics such as rectangular waves.

  -The assembled battery 10 is not restricted to what consists of four blocks.

  The voltage detection target using the flying capacitor 16 is not limited to the block voltage, and may be a battery cell voltage.

  The battery cell is not limited to a secondary battery, and may be a fuel cell, for example.

  The assembled battery 10 is not limited to being mounted on a hybrid vehicle, but may be mounted on an electric vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Assembly battery, 16 ... Flying capacitor, 20 ... Voltage detection circuit, 30 ... Battery ECU, 34 ... Control part, 38 ... Resistor, 48 ... Capacitor, SW0-SW4 ... High voltage side switching element, Sa, Sb ... Low voltage side Switching element.

Claims (4)

AC signal output means for detecting an electric leakage from an assembled battery, which is a series connection body of battery cells, to a vehicle body, and outputting an AC signal to the assembled battery via a capacitor and a resistor, and the capacitor And a leakage detection device comprising a leakage detection means for detecting the presence or absence of the leakage based on the potential between the resistors,
An apparatus for detecting a voltage of a unit battery composed of one or a plurality of adjacent battery cells constituting the assembled battery, and electrically connecting a power storage means, a voltage detection means, and the unit battery and the power storage means. A voltage detection device comprising: a high-voltage side opening / closing means that opens and closes electrically; and a low-voltage side opening / closing means that electrically opens and closes between the power storage means and the voltage detection means;
An operation means for closing both the low voltage side opening and closing means and the high voltage side opening and closing means;
Judgment for determining whether or not the leakage detection device is abnormal based on the potential between the capacitor and the resistor when the AC signal is output by the AC signal output unit and the both are closed by the operation unit. A leakage detection system. The low voltage side switching means and the high voltage side switching means each include a plurality of switching means,
It said operating means, the leakage detection system according to claim 1, characterized in that it has a function of different combinations of opening and closing means the last closing operation of the combination of the opening and closing means for closing operation during closing operation of the both. The low voltage side switching means and the high voltage side switching means each include a plurality of switching means,
The leakage detecting system according to claim 1 or 2, wherein the operating means has a function of making the number of opening / closing means to be closed when the both closing operations differ from the number of opening / closing means having been previously closed .   The voltage detection means includes an input terminal connected to the power storage means, and the input terminal is connected to the vehicle body via a resistor. The leakage detection system according to item 1.

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