JP2018098839A - Power storage device for railway vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device for a railway vehicle which can easily detect ground fault.SOLUTION: A power storage device for a railway vehicle of an embodiment includes: multiple battery modules; a housing; a first connection wire; and a first detection part. The multiple battery modules are electrically connected in a serial manner. The housing houses the multiple battery modules. The first connection wire electrically connects an electric connection part between two battery modules included in the multiple battery modules with the housing. The first detection part is provided in the first connection wire and detects a value regarding a voltage between the electric connection part and the housing.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a railway vehicle power storage device.

A vehicle is known that charges a power storage device with regenerative energy generated during deceleration.
Such a power storage device may be preferable if a ground fault can be detected more easily.

JP 2004-325382 A

  The problem to be solved by the present invention is to provide a railway vehicle power storage device capable of easily detecting a ground fault.

  The railway vehicle power storage device of the embodiment includes a plurality of battery modules, a housing, a first connection line, and a first detection unit. The plurality of battery modules are electrically connected in series. The case houses the plurality of battery modules. The first connection line electrically connects an electrical connection between two battery modules included in the plurality of battery modules and the housing. The first detection unit is provided in the first connection line and detects a value related to a voltage between the electrical connection unit and the housing.

The lineblock diagram showing the railcar power storage device of a 1st embodiment. 6 is a flowchart illustrating an example of a flow of processing by an information processing unit according to the first embodiment. The figure for demonstrating an example when a ground fault generate | occur | produces in 1st Embodiment. The figure which showed typically the circuit when the ground fault in FIG. 3 produced. The figure for demonstrating the other example when a ground fault generate | occur | produces in 1st Embodiment. The figure which showed typically the circuit when the ground fault in FIG. 5 produced. The figure which shows the modification of a voltage detection part. The block diagram which shows the electrical storage apparatus for rail vehicles of 2nd Embodiment. The figure for demonstrating an example when a ground fault generate | occur | produces in 2nd Embodiment. The figure for demonstrating the other example when a ground fault generate | occur | produces in 2nd Embodiment.

  Hereinafter, a railway vehicle power storage device according to an embodiment will be described with reference to the drawings.

(First embodiment)
First, the first embodiment will be described.
FIG. 1 is a configuration diagram illustrating a railway vehicle power storage device 1 according to the first embodiment. The railway vehicle power storage device 1 (hereinafter simply referred to as power storage device 1) includes a housing 11, a positive-side external connection terminal (external connection terminal) 12P, a negative-side external connection terminal (external connection terminal) 12N, and a set of batteries (multiple batteries). Battery module, battery module set) 14, electrical connection portion 15, voltage detection portion (first detection portion) 17, connection wire (first connection wire) 18, positive electrode side contactor (contactor) 20P, negative electrode side contact Device (contactor) 20N, controller (adjustment unit) 30, and information processing unit (determination unit, estimation unit) 40.

  The housing 11 accommodates the assembled battery 14. The housing 11 is formed of, for example, a conductive metal and has a grounding electrode (ground portion) 16A that is electrically connected thereto. The ground electrode 16 </ b> A is electrically connected to a ground electrode 16 </ b> B provided outside the housing 11.

Each of the positive external connection terminal 12P and the negative external connection terminal 12N is an example of an “external connection terminal”. The positive electrode side external connection terminal 12P is provided in the housing 11, for example, and is a terminal for connecting the positive electrode of the assembled battery 14 and an external circuit. The negative electrode side external connection terminal 12 </ b> N is provided on the housing 11, for example, and is a terminal for connecting the negative electrode of the assembled battery 14 and an external circuit.
In the example shown in the figure, the potential of the negative external connection terminal 12N is a negative potential with respect to the reference potential. For example, the positive electrode side external connection terminal 12P is + 450V (volt), and the negative electrode side external connection terminal 12N is -450V. However, the potential of each of the positive electrode side external connection terminal 12P and the negative electrode side external connection terminal 12N is not particularly limited.

The assembled battery 14 includes a plurality of battery modules connected to each other in series. The assembled battery 14 shown in the figure includes battery modules 140_1,... 140_N. In the following description, when the battery modules 140_1,... 140_N are shown without distinction, the individual battery modules 140 may be referred to as battery modules 140, and they may be collectively referred to as a plurality of battery modules 140S.
Each of the plurality of battery modules 140S may be a battery module 140 having substantially the same storage capacity, or may be a battery module 140 having a different storage capacity. In the example shown in the figure, there are N battery modules 140 having substantially the same storage capacity, and each is electrically connected in series. Here, N is an even number. The number of battery modules 140 in the assembled battery 14 is not particularly limited.
Inside the battery module 140, a voltage detector (not shown) is installed. The voltage detector transmits the voltage value of the battery module 140 to the controller 30.
The assembled battery 14 includes a first group of battery modules 14P provided on the positive electrode side with respect to an electrical connection portion 15 to be described later, and a second group provided on the negative electrode side with respect to the electrical connection portion 15. Battery module 14N. In the example shown in the figure, the first group of battery modules 14P and the second group of battery modules 14N have the same number N / 2. The numbers of the first group of battery modules 14P and the second group of battery modules 14N are not particularly limited.

The electrical connection unit 15 is a conductor that electrically connects the two battery modules 140 included in the assembled battery 14 and is, for example, a bus bar, but is not limited thereto.
The electrical connection portion 15 is provided between the first group of battery modules 14P and the second group of battery modules 14N. For example, the storage capacity of the first group of battery modules 14P is equal to the storage capacity of the second group of battery modules 14N, and the absolute value of the potential of the positive external connection terminal 12P and the potential of the negative external connection terminal 12N are When the absolute values are equal, the voltage at the electrical connection 15 is approximately 0V.
The electrical connection portion 15 and the ground electrode 16 </ b> A of the housing 11 are electrically connected by the connection line 18 via the voltage detection portion 17. For example, the voltage of the electrical connection part 15 should just be substantially the same as the voltage of the housing | casing 11, and a voltage value is not specifically limited. In the following description, the electrical connection part 15 may be called a neutral point.

  The ground electrodes 16A and 16B are electrodes that are electrically grounded. The ground electrode 16 </ b> A is connected to a terminal different from the terminal connected to the electrical connection unit 15 of the voltage detection unit 17 connected to the electrical connection unit 15. The ground electrode 16 </ b> B is electrically connected to the housing 11.

  The voltage detection unit 17 is installed between the electrical connection unit 15 and the ground electrode 16A, and detects a DC voltage (voltage) between the electrical connection unit 15 and the ground electrode 16A. The voltage detection unit 17 transmits the detected voltage to the information processing unit 40.

  The positive contactor 20P is electrically connected in series between the positive external connection terminal 12P and the positive terminal of the first group of battery modules 14P. In other words, the positive contactor 20P is installed between the positive external connection terminal 12P and the positive terminal of the first group of battery modules 14P. The positive-side contactor 20P is, for example, a high-speed circuit breaker that makes contact between the positive-side external connection terminal 12P and the positive-side terminal of the battery module 14P of the first group or shuts off the contact state. High-Speed Breaker (HB). Based on an instruction from the controller 30, the positive electrode side contactor 20P brings the positive electrode side external connection terminal 12P and the positive electrode side terminal of the battery module 14P of the first group into a contact state or a cutoff state.

  The negative electrode side contactor 20N is electrically connected in series between the negative electrode side external connection terminal 12N and the negative electrode side terminal of the second group of battery modules 14N. In other words, the negative electrode side contactor 20N is installed between the negative electrode side external connection terminal 12N and the negative electrode side terminal of the second group of battery modules 14N. The negative electrode side contactor 20N is, for example, a high-speed breaker (HB) that brings the negative electrode side external connection terminal 12N and the negative electrode side terminal of the second group of battery modules 14N into a contact state or a disconnected state. It is. The negative electrode side contactor 20N brings the negative electrode side external connection terminal 12N and the negative electrode side terminal of the battery module 14N of the second group into a contact state or a cutoff state based on an instruction from the controller 30.

The controller 30 controls the power storage device 1. The controller 30 and the information processing unit 40 to be described later are software function units realized by a processor such as a CPU (Central Processing Unit) executing a program stored in a program memory, for example. Some or all of these functional units may be realized by hardware such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), or FPGA (Field-Programmable Gate Array).
The controller 30 includes a voltage adjustment unit 31 and a contactor control unit 32.

  The voltage adjustment unit 31 adjusts the voltage of each battery module 140 of the assembled battery 14 to be substantially the same. The voltage adjustment unit 31 adjusts the voltage of each battery module 140 based on the voltage of each battery module 140 received by the controller 30 from the voltage detector installed inside each battery module 140.

  The contactor control unit 32 controls the positive electrode side contactor 20P and the negative electrode side contactor 20N. For example, when an abnormal current such as an overcurrent flows into the positive external connection terminal 12P, the contactor control unit 32 shuts off the positive contactor 20P and the negative contactor 20N to protect the assembled battery 14 To do.

  The information processing unit 40 processes information when a connection portion connecting each battery module 140 of the assembled battery 14 is grounded. The information processing unit 40 includes a ground fault determination unit 41 and a ground fault location estimation unit 42. In addition, in the same figure, although the information processing part 40 is provided separately from the controller 30, it may be provided integrally.

  The “ground fault” in the present application refers to a state in which a connection portion such as a wiring connecting each battery module 140 of the assembled battery 14 is in contact with a part of the housing 11 due to vibration of the railway vehicle or the like. . “Ground fault” as used in the present application refers to a moment when a connection part connecting each battery module 140 comes into contact with a part of the casing 11 and then comes into non-contact with a part of the casing 11 that has been in contact. Including the case of short circuit.

  The ground fault determination unit 41 determines whether or not a ground fault has occurred based on the voltage of the electrical connection unit 15 received by the controller 30 from the voltage detection unit 17. The ground fault determination unit 41 transmits a determination result regarding the presence or absence of a ground fault to the controller 30.

  The ground fault location estimation unit 42 estimates a ground fault location based on the voltage of the electrical connection unit 15 received by the controller 30 from the voltage detection unit 17. The ground fault location estimation unit 42 transmits information indicating the estimated ground fault location to the controller 30.

FIG. 2 is a flowchart illustrating an example of a processing flow by the information processing unit of the first embodiment.
First, the ground fault determination unit 41 acquires the voltage value Udcpt of the electrical connection unit 15 received by the information processing unit 40 from the voltage detection unit 17 (step S10). The ground fault determination unit 41 may periodically acquire the voltage value Udcpt of the electrical connection unit 15 or may acquire the voltage value Udcpt of the electrical connection unit 15 in accordance with an instruction from the controller 30. The voltage value Udcpt of the electrical connection portion 15 is in a predetermined voltage range in a state where there is no ground fault, and the representative value of the voltage range is approximately 0V. And the ground fault determination part 41 determines whether the voltage value Udcpt of the electrical connection part 15 is substantially 0V (step S11). When the voltage value Udcpt of the electrical connection unit 15 is approximately 0 V, this flowchart ends.

On the other hand, when the voltage value Udcpt of the electrical connection unit 15 is not approximately 0 V, the ground fault determination unit 41 determines that a ground fault has occurred.
When it is determined that a ground fault has occurred, the ground fault location estimation unit 42 determines whether or not the voltage value Udcpt of the electrical connection unit 15 is a positive value (step S12). When the voltage value Udcpt of the electrical connection unit 15 is a positive value, the ground fault location estimation unit 42 uses the following equation (1) to calculate the ground fault based on the voltage value Udcpt of the electrical connection unit 15. The battery module 140 — i at the place where it has been estimated is estimated (step S13A).
On the other hand, when the voltage value Udcpt is not a positive value, the ground fault location estimation unit 42 uses the following equation (2) to calculate the battery module at the ground fault location based on the voltage value Udcpt of the electrical connection unit 15. 140_j is estimated (step S13B).

  Here, the method for estimating the place where the ground fault location estimation unit 42 has ground fault will be described using FIG. 3 to FIG. 6. FIG. 3 is a diagram for explaining an example when a ground fault occurs in the first group of battery modules 14P. FIG. 4 is a diagram schematically showing a circuit when a ground fault occurs in FIG. FIG. 5 is a diagram for explaining an example when a ground fault occurs in the second group of battery modules 14N. FIG. 6 is a diagram schematically showing a circuit when a ground fault occurs in FIG.

In FIG. 3, among the N / 2 battery modules 140 electrically connected in series included in the first group of battery modules 14 </ b> P, the battery modules 140 </ b> _i−1 and i connected to the i−1th battery module 140 </ b> P are connected to each other. The state where the path | route LA between the battery modules 140_i connected to the th is grounded is shown.
When the path LA is grounded and contacts a part of the housing 11, the terminal of the battery module 140 in the path LA and the housing 11 are connected by the path LB. For this reason, when the voltage of the path LA until the occurrence of the ground fault is higher than the voltage (0 V) of the housing 11, the current flows from the path LA toward the housing 11 when the ground fault occurs. The voltage at LA becomes the ground potential. As a result, the potential of the entire assembled battery 14 with respect to the ground potential decreases. Along with this, the voltage of the battery module 140 — i−1 connected i−1 drops. Although the voltage detection unit 17 has a high internal impedance of the voltage dividing resistor and only a weak current flows, the closed circuit LPP shown in FIG. 3 is defined and described below.

  The closed circuit LPP shown in FIG. 3 is equivalent to the circuit shown in FIG. In other words, the voltage detected by the voltage detector 17 is the sum of the voltages stored in the battery modules 140 from the (i + 1) th battery module 140_i + 1 to the N / 2th battery module 140_N / 2.

  Accordingly, the voltage value Udcpt1 of the electrical connection unit 15 detected by the voltage detection unit 17 is a value represented by the following expression (1). Here, Ubat is the voltage value stored in each battery module, N is the number of battery modules 140 included in the assembled battery 14, and i is the location of the battery module 140 connected to the path LA where the ground fault has occurred (N pieces) The battery module 140 connected i-th of the serial connection is shown.

  Udcpt1 = Ubat × (N / 2−i + 1) (1)

  The ground fault location estimation unit 42 estimates the location where the ground fault has occurred by calculating i based on the formula (1).

FIG. 5 also shows the j−1th connected battery module among the N / 2 battery modules electrically connected in series included in the second group of battery modules 14N. The state where the path LC with the connected battery module is grounded is shown.
When the path LC is grounded and contacts a part of the housing 11, the wiring in the path LC and the housing 11 are electrically connected by the path LD. For this reason, when the voltage of the path LC until the occurrence of the ground fault is lower than the voltage (0 V) of the casing 11, a current flows from the casing 11 toward the path LC, so that the voltage of the path LC is grounded. Become potential. Thereby, the electric potential with respect to the ground potential of the whole assembled battery 14 rises. Along with this, the voltage of the battery module 140_j-1 connected to the (j-1) th rises. The voltage detection unit 17 has a high internal impedance of the voltage dividing resistor and only a weak current flows. The closed circuit LPN shown in FIG. 5 is defined and described below.

  The closed circuit LPN shown in FIG. 5 is equivalent to the circuit shown in FIG. In other words, the voltage detected by the voltage detection unit 17 is included in the assembled battery 14 from 14_ (N + 2) / 2nd battery module 14_ (N + 2) / 2 to j−1th battery module 14_j−1. This is the sum of the voltages stored in each battery module 140.

  Accordingly, the voltage value Udcpt2 of the electrical connection portion 15 is a value represented by the following expression (2). Here, Ubat is the voltage value stored in each battery module 140, N is the number of battery modules included in the assembled battery 14, and j is the location of the battery module connected to the path LC where the ground fault has occurred (N The battery module connected in the serial connection).

Udcpt2 = Ubat × {(N + 2) / 2− (j−1) −1}
= Ubat × (N / 2−j + 1) (2)

  The ground fault location estimation unit 42 estimates a ground fault location by calculating j based on the above equation (2).

  Returning to FIG. 2, the ground fault location estimation unit 42 transmits the estimated ground fault location to the controller 30 after completing the process shown in step S <b> 13 </ b> A or S <b> 13 </ b> B. Based on the information received from the ground fault location estimation unit 42, the controller 30 stores the ground fault location in a storage area (not shown) (step S14).

  According to the first embodiment described above, the power storage device 1 detects the voltage between the electrical connection unit 15 between the two battery modules included in the assembled battery 14 and the housing 11. 17. Thereby, according to the electrical storage apparatus 1, a ground fault can be easily detected based on the value which the voltage detection part 17 detected.

  In addition, the voltage detection unit 17 detects a value related to the voltage between the electrical connection unit 15 and the ground electrode 16 </ b> A of the housing 11. Thereby, according to the electrical storage apparatus 1, the voltage of the housing | casing 11 becomes substantially 0V, and a ground fault can be detected easily.

  Further, the electrical connection unit 15 is provided between the first group of battery modules 14P and the second group of battery modules 14N, and the voltage thereof is substantially 0 V in a state where there is no ground fault. According to 1, the voltage of the electrical connection portion 15 and the voltage of the housing 11 are substantially the same, and a ground fault can be easily detected.

  Moreover, the ground fault determination part 41 which determines the presence or absence of a ground fault based on the value regarding the voltage detected by the voltage detection part 17 is provided. Thereby, according to the electrical storage apparatus 1, a ground fault can be detected easily.

  In addition, the power storage device 1 estimates a place where a ground fault has occurred based on a value related to the voltage detected by the voltage detection unit 17 and a voltage value of at least one battery module 140 included in the assembled battery 14. A place estimation unit 42 is provided. Thereby, according to the electrical storage apparatus 1, the place where the ground fault in the electrical storage apparatus 1 can be estimated.

  The ground fault location estimation unit 42 is detected by the voltage detection unit 17 after the voltage value of the assembled battery 14 is adjusted to be approximately the same by the voltage adjusting unit 31 that adjusts the voltage value of the assembled battery 14 to be approximately the same. Based on the value relating to the voltage and the voltage value of one battery module 140 included in the assembled battery 14, the location where the ground fault has occurred is estimated. Thereby, according to the electrical storage apparatus 1, the ground fault location estimation part 42 can estimate the ground fault location in the electrical storage apparatus 1 easily using said (1) or (2) Formula.

  In addition, the power storage device 1 includes contactors 20P and 20N provided electrically in series between the external connection terminals 12P and 12N and the assembled battery 14. Thereby, according to the electrical storage apparatus 1, the assembled battery 14 can be protected from an overcurrent.

(Modification of the first embodiment)
A modification of the first embodiment will be described with reference to FIG. FIG. 7 is a diagram for explaining a modification of the first embodiment.
As illustrated in FIG. 7, the power storage device 1 may include a current detection unit 170 and a resistor 171 instead of the voltage detection unit 17. In this case, the information processing unit 40 calculates a voltage value by multiplying the current value Udcct detected by the current detection unit 170 by the resistance value Re of the resistor 171. Then, the information processing unit 40 determines a ground fault and estimates a ground fault location based on the calculated voltage value. The current detection unit 170 and the resistor 171 are examples of the “first detection unit”. Further, the current detection unit 170 and the resistor 171 may be used instead of the voltage detection unit 17 in the second embodiment. In this case, the current detection unit 170 and the resistor 171 are also examples of the “second detection unit”.

  In addition, although the case where the assembled battery 14 was accommodated in the housing | casing 11 was demonstrated in 1st Embodiment, it is not limited to this. The power storage device 1 according to the first embodiment may not include the housing 11. When the housing 11 is not provided, when a connection portion that electrically connects the two battery modules 140 of the assembled battery 14 is grounded, a closed circuit is formed via an object (for example, a line) having a voltage of approximately 0V. Made. Thereby, the ground fault location estimation unit 42 estimates the location where the ground fault has occurred based on the voltage detected by the voltage detection unit 17.

(Second Embodiment)
Next, a second embodiment will be described. FIG. 8 is a diagram for explaining the second embodiment. The same components as those described above are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 8, the power storage device 1 of the second embodiment includes a plurality of assembled batteries (battery module sets) 14A, 14B,..., 14M, and a plurality of positive electrode side contactors (contactors) 20PA. 20PB,... 20PM, a plurality of negative electrode side contactors (contactors) 20NA, 20NB,..., 20NM, and a plurality of voltage detectors 17A, 17B,.
The assembled batteries 14A, 14B,..., 14M correspond to the assembled battery 14 of the first embodiment. In the following description, the assembled batteries 14A, 14B, ..., 14M may be collectively referred to as an assembled battery 14. In addition, the voltage detection units 17A, 17B,..., 17M may be collectively referred to as a voltage detection unit 17. Moreover, the positive electrode side contactors 20PA, 20PB,... 20PM may be collectively referred to as a positive electrode side contactor 20P. Further, the negative electrode side contactors 20NA, 20NB,..., 20NM may be collectively referred to as a negative electrode side contactor 20N. Each of the assembled batteries 14A, 14B,..., 14M is electrically connected to each other in parallel via the positive electrode side contactor 20P and a plurality of negative electrode side contactors 20N.

For example, the battery module 140_N / 2 and the battery module 140_N / 2 + 1 in the assembled battery 14A are connected by the electrical connection unit 15A. The electrical connection unit 15A is grounded by the ground electrode 16A via the voltage detection unit 17.
The assembled batteries 14B,..., 14M are the same as the assembled battery 14A. In the present embodiment, the connection line 18 that electrically connects the electrical connection portion 15 of the assembled battery 14A and the ground electrode 16A is an example of a “first connection line”. Further, the voltage detection unit 17 provided in the connection line 18 that electrically connects the electrical connection unit 15 of the assembled battery 14A and the ground electrode 16A is an example of a “first detection unit”. The connection line 18 that electrically connects the electrical connection portion 15 of the battery pack 14B and the ground electrode 16A is an example of a “second connection line”. Moreover, the voltage detection part 17 provided in the connection line 18 which electrically connects the electrical connection part 15 of the assembled battery 14B and the grounding electrode 16A is an example of a “second detection part”.

  The ground fault location estimation unit 42 according to the second embodiment estimates the location where the ground fault has occurred based on the value related to the voltage detected by each of the plurality of voltage detection units 17.

A method for estimating a place where the ground fault location estimation unit 42 has ground fault will be described with reference to FIGS. 9 and 10. FIG. 9 is a diagram for explaining an example when a ground fault occurs inside the assembled battery 14A (first battery module set). FIG. 10 is a diagram for explaining an example when a ground fault occurs outside the assembled battery 14A.
Here, in the example shown in FIG. 9, the case where a ground fault occurs inside the assembled battery 14A means a case where a ground fault occurs inside the contactors 20PA and 20NA corresponding to the assembled battery 14A. For example, when a ground fault occurs inside the assembled battery 14A, the path LE between the two battery modules 140 included in the assembled battery 14A comes into contact with the casing 11, so that the wiring and the casing in the path LE are connected. This is a case where the body 11 is electrically connected by the path LF and a ground fault occurs. In the example shown in FIG. 10, the case where a ground fault occurs outside the battery pack 14A means that a ground fault occurs outside the contactors 20PA and 20NA corresponding to the battery pack 14A. To do. For example, when a ground fault occurs outside the battery pack 14A, the path LG between the positive external connection terminal 12P and the positive contactor 20PA comes into contact with the housing 11, thereby causing the path LG. This is a case where the wiring in the housing and the housing 11 are electrically connected by the path LF, and a ground fault occurs in the path LH.
As shown in FIG. 9, when a ground fault occurs inside the assembled battery 14A, a closed circuit LPP-A passing through the voltage detection unit 17A is created as described above. Further, when a ground fault occurs inside the assembled battery 14A, a closed circuit LPP-B is created via the voltage detection unit 17B of the assembled battery 14B connected in parallel with the assembled battery 14A. As shown in FIG. 10, when a ground fault occurs outside the assembled battery 14A, a closed circuit LPP-C that passes through the voltage detection unit 17B is created. In the closed circuit LPP-B and the closed circuit LPP-C, when an abnormal current flows through the contactor 20P due to a ground fault, the contactor 20P enters a cut-off state. Alternatively, when the ground fault determination unit 41 detects a ground fault, the ground fault determination unit 41 shuts off the contactors 20P and 20N via the contactor control unit 32 of the controller 10 in order to protect the assembled battery 14. It can be.

When the path LE is grounded and contacts a part of the housing 11, the path LE and the housing 11 are connected by the path LF. In this case, as already described, the closed circuit LPP-A is created, and the voltage value detected by the voltage detection unit 17A is the value shown in the equation (1) or (2).
In the second embodiment, when the assembled battery 14A has a ground fault, the assembled batteries 14A to 14M undergo voltage fluctuations due to the influence of the assembled battery 14A.

  Here, depending on whether or not a ground fault has occurred in the assembled battery 14 by individually disconnecting the parallel connection of the assembled battery 14 (that is, by individually bringing the contactor 20P and the contactor 20N into a disconnected state). The detected voltage is different. The ground fault location estimation unit 42 can detect the assembled battery 14 in which a ground fault has occurred based on the detected voltage.

For example, when a ground fault has occurred in the assembled battery 14 (for example, the assembled battery 14A) that has been disconnected from the parallel connection, voltage fluctuations of other assembled batteries 14 (for example, an assembled battery other than the assembled battery 14A) are normal. Returning to the value, voltage abnormality is observed only in the assembled battery 14 (for example, the assembled battery 14A) that has been disconnected in parallel. In other words, the above case is a case where a ground fault has occurred on the assembled battery 14 side from the contactors 20P and 20N that have been disconnected in parallel. The “normal value” of the voltage fluctuation includes a state where the voltage is indefinite.
Alternatively, when there is no ground fault in the assembled battery 14 that has been disconnected in parallel, the voltage variation of the assembled battery 14 that has been disconnected in parallel returns to a normal value, and the assembled batteries other than the assembled battery 14 that has been disconnected in parallel Voltage abnormality is observed in all 14. In other words, the above case is a case where a ground fault has occurred outside the contactors 20P and 20N that have been disconnected in parallel.

  The ground fault location estimation unit 42 can identify the assembled battery 14 in which a ground fault has occurred by executing the processing of the above procedure. In addition, the ground fault location estimation part 42 controls the positive electrode side contactor 20P and the some negative electrode side contactor 20N via the contactor control part 32 of the controller 30, and individual parallel connection of the assembled battery 14 is carried out. It can be solved.

  In the second embodiment, the ground fault location estimation unit 42 estimates the assembled battery 14 including the ground fault voltage detection unit 17 depending on whether or not the voltage value detected by the voltage detection unit 17 is indefinite. . In the second embodiment, the ground fault location estimation unit 42 uses the same technique as that of the first embodiment for specifying the ground fault point in the battery pack 14 in which the ground fault is specified. It may be taken. That is, the ground fault location estimation unit 42 estimates the ground fault location based on the voltage value detected by the voltage detection unit 17 using the formula (1) or (2), as in the first embodiment. To do.

  According to the second embodiment described above, the ground fault location estimation unit 42 estimates the location where the ground fault has occurred based on the values relating to the voltages detected by the voltage detection units 17A and 17B. Thereby, according to the electrical storage apparatus 1, even when it has the assembled battery 14B electrically connected in parallel with respect to the assembled battery 14A, whether or not a ground fault has occurred in any of the assembled batteries 14 Can be estimated.

  According to at least one embodiment described above, the railway vehicle power storage device 1 includes the assembled battery 14, the housing 11, the electrical connection unit 15, and the connection line 18 that electrically connects the housing 11. And a voltage detection unit 17 that detects a value related to a voltage between the electrical connection unit 15 and the casing 11. Thereby, according to the electrical storage apparatus 1, a ground fault can be detected easily.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Railway vehicle electrical storage apparatus, 11 ... Housing | casing, 12P ... Positive electrode side external connection terminal, 12N ... Negative electrode side external connection terminal, 14, 14A, 14B ... Assembly battery, 140S ... Multiple battery modules, 140 ... Battery module, DESCRIPTION OF SYMBOLS 15 ... Electrical connection part, 16A, 16B ... Ground electrode, 17 ... Voltage detection part, 18 ... Connection line, 20P ... Positive electrode side contactor, 20N ... Negative electrode side contactor, 30 ... Controller, 31 ... Voltage adjustment part, 32 ... Contactor control unit, 40 ... Information processing unit, 41 ... Ground fault determination unit, 42 ... Ground fault location estimation unit

Claims (8)

A plurality of battery modules electrically connected in series;
A housing containing the plurality of battery modules;
A first connection line electrically connecting an electrical connection between two battery modules included in the plurality of battery modules and the housing;
A first detection unit that is provided in the first connection line and detects a value related to a voltage between the electrical connection unit and the housing;
A railway vehicle power storage device. The housing has a ground part,
The first connection line electrically connects the electrical connection portion and the ground portion of the housing via the first detection unit,
The first detection unit detects a value related to a voltage between the electrical connection unit and a ground portion of the housing.
The railway vehicle power storage device according to claim 1. The voltage of the electrical connection detected by the first detection unit in the absence of a ground fault is in a predetermined voltage range.
The railway vehicle power storage device according to claim 1 or 2. A determination unit for determining the presence or absence of a ground fault based on a value related to the voltage detected by the first detection unit;
The power storage device for a railway vehicle according to any one of claims 1 to 3. An estimation unit that estimates a location where a ground fault has occurred based on a value related to the voltage detected by the first detection unit and a voltage value of at least one battery module included in the plurality of battery modules;
The power storage device for a railway vehicle according to any one of claims 1 to 4. An adjustment unit for adjusting the voltage values of the plurality of battery modules to be substantially the same;
The estimation unit includes a value relating to a voltage detected by the first detection unit after the voltage values of the plurality of battery modules are adjusted to be substantially the same by the adjustment unit, and one of the plurality of battery modules included in the estimation unit. Based on the voltage value of the battery module, estimate the location where the ground fault occurred,
The railway vehicle power storage device according to claim 5. An external connection terminal;
A contactor provided between the external connection terminal and the plurality of battery modules;
Further comprising
The first detection unit detects a value related to a voltage between the electrical connection unit and the housing in a state where the contactor is opened,
The estimation unit estimates a location where a ground fault has occurred based on a value related to a voltage detected by the first detection unit in a state where the contactor is opened.
The railway vehicle power storage device according to claim 5 or 6. A first battery module set including the plurality of battery modules;
A second battery module set including another plurality of battery modules and electrically connected in parallel to the first battery module set;
A second connection line electrically connecting the electrical connection between the two battery modules included in the second battery module set and the housing;
A second detection unit that is provided in the second connection line and detects a value related to a voltage between the electrical connection unit and the housing included in the second battery module set;
An estimation unit that estimates a location where a ground fault has occurred based on a value related to the voltage detected by the first detection unit and a value related to the voltage detected by the second detection unit;
The power storage device for a railway vehicle according to any one of claims 1 to 7, further comprising:

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