JP2015100184A - Grounding device, and grounding device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grounding device and a grounding device for a vehicle which are excellent in maintainability and capable of improving operational stability and responsiveness.SOLUTION: A grounding device according to an embodiment includes a first terminal, a second terminal, a plurality of semiconductor switches having a first main electrode, a second main electrode, and a control electrode. The first terminal is electrically connected to a conductive member having a high voltage. The second terminal is electrically connected to a conductive member having a predetermined potential for the grounding side. The plurality of semiconductor switches are connected in series between the first terminal and the second terminal.

Description

  Embodiments described herein relate generally to a grounding device and a vehicle grounding device.

  Conventionally, a railway AC electric vehicle (hereinafter referred to as “electric vehicle” as appropriate) that travels by receiving an extra high voltage such as 20 kV or 25 kV is connected to the vehicle body by grounding a current collector such as a pantograph. A grounding device called a protective grounding switch or the like is provided for the purpose of stopping power transmission (hereinafter referred to as “feeding power”) (for example, refer to Patent Document 1 and Patent Document 2).

  This type of grounding device is usually provided on the roof of an electric vehicle, and when a switch provided in the cab of the electric vehicle is operated, the electromagnetic valve built into the grounding device or the vehicle body side is provided. Actuating air is supplied to the cylinder of the grounding device by the provided solenoid valve. When operating air is supplied to the cylinder of the grounding device, the blade of the grounding device that is grounded to the vehicle body is driven, and this blade is brought into contact with the contact on the current collector side.

  When the current collector is in contact with the train line while the blade of the ground device is in contact with the contact on the current collector side, the train line is grounded to the vehicle body through the ground device. In the case of AC feeding, the distance relay at the substation detects a phase shift due to grounding, thereby detecting grounding and stopping feeding. Thus, in addition to the purpose of stopping feeding, a grounding device may be used for the purpose of ensuring the safety of workers from extra high pressure during maintenance work.

JP-A-8-153445 JP 2010-73567 A

  However, according to the conventional grounding device that drives the blade by the cylinder and contacts the current collector, the movable part for transmitting the driving force of the cylinder to the blade, the contact for bringing the blade into contact with the current collector, etc. Since it is a mechanical type having parts, there is a risk of wear of parts and the like, and maintenance inspection is required.

  The problem to be solved by the present invention is to provide a grounding device and a vehicle grounding device excellent in maintainability.

  The grounding device of the embodiment has a first terminal, a second terminal, and a plurality of semiconductor switches having a first main electrode, a second main electrode, and a control electrode. The first terminal is electrically connected to a conductive member having a high voltage. The second terminal is electrically connected to a conductive member having a predetermined potential on the ground side. The plurality of semiconductor switches are connected in series between the first terminal and the second terminal.

The figure which shows an example of the typical structure of the electric circuit relevant to the power receiving in the alternating current electric vehicle for railroads provided with the grounding apparatus by embodiment. It is a figure showing typically an example of composition of a grounding device by an embodiment, and a figure showing an example of composition which paid its attention to a side as a circuit. It is a figure which shows typically an example of a structure of the grounding apparatus by embodiment, and is a figure which shows the structural example which paid its attention to the side as a structure. The figure for demonstrating the 1st example of arrangement | positioning of the grounding apparatus by embodiment. The figure for demonstrating the 2nd example of arrangement | positioning of the grounding apparatus by embodiment. The figure which shows the structural example of the drive circuit of the grounding device by embodiment. The figure which shows the structure of the drive circuit by the 1st modification of the grounding device by embodiment. The figure which shows the structure of the drive circuit by the 2nd modification of the grounding apparatus by embodiment. The figure for demonstrating the structure of the grounding apparatus of the modification of embodiment. Sectional drawing of the grounding apparatus of the modification of embodiment. The figure which shows an example of a structure of the control circuit of the grounding apparatus by embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
In addition, although this embodiment demonstrates the case where a grounding device is applied to the alternating current electric vehicle for electric railways, the grounding device by this embodiment is arbitrary in the limit for the purpose of grounding.

(Description of configuration)
FIG. 1 is a diagram illustrating an example of a representative configuration of an electric circuit related to power reception in an electric railway AC electric vehicle including a grounding device according to the present embodiment.
The AC electric vehicle illustrated in FIG. 1 is an AC electric vehicle that is used in an electric railway electrified with a single-phase alternating current of a special high voltage such as 20 kV or 25 kV. The electric vehicle shown in this example includes a pantograph 2 that is a type of current collector for receiving power from the train line 1.

  The pantograph 2 is connected to an input end of a main circuit breaker 3 such as a vacuum circuit breaker via an extra high voltage cable 12 to which cable heads 13a and 13b are attached. The extra high voltage cable 12 is, for example, a coaxial cable. The pantograph 2 is connected to one end of the inner conductor, and the outer conductor is grounded to the vehicle body 11. The output terminal of the main circuit breaker 3 is connected to one end of the primary side winding 41 of the main transformer 4. The electric power received from the train line 1 by the pantograph 2 is supplied to one end side of the primary winding 41 of the main transformer 4 via the main circuit breaker 3.

  The other end of the primary side winding 41 of the main transformer 4 is connected to the ground terminal block 14, and the ground terminal block 14 is connected to a ground mechanism 5 provided on an axle or the like. The other end of the primary winding 41 of the main transformer 4 is grounded to the traveling rail 6 via the grounding mechanism 5. As a result, a return circuit is formed between the other end of the primary side winding 41 of the main transformer 4 and the substation, and the secondary side windings 42a and 42b of the main transformer 4 are respectively used as power converters. It becomes possible to take out the electric power stepped down to the voltage suitable for 7a, 7b.

  The secondary winding 42a of the main transformer 4 is connected to the input part of the power converter 7a, and the traveling main motor 8 is connected to the output part of the power converter 7a. The power conversion device 7a drives a main motor 8 for traveling. As a result, the electric vehicle travels on the rail 6. Moreover, the secondary side winding 42b of the main transformer 4 is connected to the input part of the power converter 7b, and the auxiliary | assistant rotary machine 9, such as an air blower, is connected to the output part of the power converter 7b. The power converter 7b supplies power for the auxiliary rotating machine 9 such as a blower, service power for passengers, and the like.

  The primary side of the main transformer 4 is connected to a lightning arrester 10 for discharging a surge caused by a lightning strike or the like. In an AC electric vehicle in Japan, the lightning arrester 10 is generally not connected directly to a current collector like a DC electric vehicle, but is provided on the primary side of the main transformer 4. Further, the lightning arrester 10 is not limited to the rooftop of the electric vehicle, and can be disposed at a position close to the primary side of the main transformer 4. Furthermore, the lightning arrester 10 can be stored and arranged in a special high voltage equipment frame in the vehicle or in a high voltage equipment box under the floor.

  The grounding device 15 according to the present embodiment is electrically connected between the pantograph 2 and the vehicle body 11 so as to be positioned in the vicinity of the pantograph 2. The grounding device 15 does not conduct during vehicle operation, is controlled to a non-grounding state (non-conducting state), and maintains an insulating state with respect to extra high pressure, like an insulator for supporting the pantograph 2. The sudden surge applied to the pantograph 2 is discharged by the lightning arrester 10 to protect each device of the electric vehicle from the surge. When the pantograph 2 needs to be grounded, an operator or the like sends a control signal to the grounding device 15 by operating a switch provided in a driver's cab or the like, like a conventional protective grounding switch (EGS). Thus, the grounding device 15 is turned on to ground the pantograph 2 to the vehicle body 11.

  In this case, since the electric charge (for example, the residual charge of the electrostatic capacity of the extra high voltage cable 12) stored in a device having a power storage function such as a capacitor is discharged via the grounding device 15, the electric charge is stored in the device. Electric shock due to the generated electric charge is prevented, and the safety of the worker can be ensured. Further, if the control signal is continuously sent from the outside so that the grounding device 15 becomes conductive and maintains the grounded state, the pantograph 2 of the electric vehicle accidentally contacts the train line 1 during the work, and the train line 1 changes to the pantograph 2. Even if an extra high voltage is applied, the ground wire 15 is grounded by the grounding device 15. In this case, by detecting a shift in the phase of the current flowing in the train line 1, the substation side detects grounding and immediately stops power feeding, thereby ensuring worker safety.

FIG. 2 is a diagram schematically illustrating an example of the configuration of the grounding device 15 according to the present embodiment, and is a diagram illustrating a configuration example focusing on a side as a circuit.
Schematically, the grounding device 15 includes a terminal plate 18, a terminal plate 19, and a plurality of semiconductor switches 151, 152, 153, 154, and 155. Here, the terminal plate 18 constitutes a first terminal that is electrically connected to a conductive member that becomes a high voltage, and the terminal plate 19 is electrically connected to the conductive member that becomes a predetermined potential (for example, ground potential) on the ground side. A second terminal to be connected to each other. In the present embodiment, the terminal plate 18 is connected to the pantograph 2, and the terminal plate 19 is grounded to the vehicle body 11.
In the present embodiment, the predetermined potential on the ground side is assumed to be the ground potential. However, the predetermined potential can be arbitrarily set from the viewpoint of safety of workers.

  The plurality of semiconductor switches 151, 152, 153, 154, 155 have a first main electrode, a second main electrode, and a control electrode, and are connected in series between the terminal plate 18 and the terminal plate 19, They are arranged in rows. In the present embodiment, each of the semiconductor switches 151, 152, 153, 154, and 155 is, for example, a pressure contact type IGBT (Insulated-Gate Bipolar Transistor), and the semiconductor switches 151, 152, 153, 154, and 155 are stacked. Yes. However, the semiconductor switches 151, 152, 153, 154, and 155 are not limited to this example, and may be thyristors, FETs (Field Effect Transistors), or any semiconductor switches. obtain.

  Since a semiconductor switch having such a high dielectric strength that can insulate a special high voltage alone is not common, in this embodiment, for example, a plurality of semiconductor switches 151, 152, 153, 154 having a breakdown voltage of several thousand volts are used alone. By connecting 155 in series, the voltage applied to each semiconductor switch is relaxed. Therefore, the number of semiconductor switches constituting the grounding device 15 is arbitrary depending on the withstand voltage of each semiconductor switch as long as it can function as a switch without causing a problem in normal operation or withstand voltage test. Can be set.

FIG. 3 is a diagram schematically illustrating an example of the configuration of the grounding device 15 according to the present embodiment, and is a diagram illustrating a configuration example focusing on a side surface as a structure.
In the present embodiment, from the viewpoint of the structure, the grounding device 15 includes the accommodating portion 21 and the sealing portion in addition to the terminal plates 18 and 19 and the plurality of semiconductor switches 151, 152, 153, 154, and 155 described above. 23 and a sealing portion 24 are further provided.

  The accommodating portion 21 is an insulating cylinder that accommodates a plurality of semiconductor switches 151, 152, 153, 154, and 155 arranged in a row. The accommodating portion 21 may be, for example, a hollow porcelain insulator or a polymer insulating material such as a polymer. The height of the housing portion 21 is the leakage of the outer surface of the housing portion 21 in order to ensure electrical insulation between the sealing portion 23 and the sealing portion 24 on the outer surface of the housing portion 21 exposed to the external environment. Determined by distance (surface leakage distance).

  In the present embodiment, the sealing portion 23 is a conductive metal fitting that seals one opening of the housing portion 21 in a state of being electrically connected to one end of a switch formed of an assembly of a plurality of semiconductor switches. The terminal board 18 is fixed. The sealing portion 23 is integrated with the terminal plate 18 to form a first terminal that is electrically connected to a conductive member having a high voltage. However, the sealing portion 23 is not limited to a conductive metal fitting, and may be an insulating member.

  Moreover, in this embodiment, the sealing part 24 is a conductive metal fitting that seals the other opening of the housing part in a state of being electrically connected to the other end of the switch formed of an assembly of a plurality of semiconductor switches. It is fixed to the terminal board 19. In the present embodiment, the sealing portion 24 is integrated with the terminal plate 19 to form a second terminal that is electrically connected to a conductive member having a predetermined potential on the ground side. However, the sealing portion 24 is not limited to a conductive metal fitting, and may be an insulating member.

  A plurality of semiconductor switches 151, 152, 153, 154, and 155 are incorporated in the housing portion 21. More specifically, a necessary number of semiconductor switches 151, 152, 153, 154, and 155 are stacked between the high-voltage side terminal plate 18 and the ground-side terminal plate 19 and are assembled in the housing portion 21. It is housed in such a way. When the thickness (height) of the assembly of the semiconductor switches 151, 152, 153, 154, and 155 is insufficient with respect to the required height of the housing portion 21, a conductive spacer 22 is appropriately added. Good.

FIG. 4 is a diagram for explaining a first arrangement example of the grounding device 15 according to the present embodiment.
In the example shown in FIG. 4, the housing portion 21 of the grounding device 15 also serves as a hollow insulator 25 for supporting a pedestal 2 </ b> A to which a pantograph 2, which is a type of vehicle current collector, is attached. In other words, the plurality of semiconductor switches 151, 152, 153, 154, and 155 constituting the grounding device 15 are housed inside the insulator 25 for supporting the pantograph 2. The number of the insulators 25 for supporting the pantograph 2 varies depending on the specifications of the electric vehicle and is arbitrary, but the grounding device 15 according to the present embodiment is used as at least one insulator for supporting the pantograph 2.

  In the example of FIG. 4, the terminal plate 18 of the grounding device 15 is connected to the pedestal 2 </ b> A of the pantograph 2, is electrically connected to the pantograph 2, and is shown in FIG. 1 through a conductor 28 connected to the pedestal 2 </ b> A. The extra high voltage cable 12 is connected to the cable head 13a. The terminal plate 19 of the grounding device 15 is fixed to the vehicle body 11 by a pedestal (not indicated), and a wiring seat 20 attached to the terminal plate 19 and a grounding seat 27 attached to the vehicle body 11. The vehicle body 11 is grounded via a ground wire 26 therebetween. However, it is not limited to the example of FIG. 4, and the grounding device 15 may be arranged alone on the roof of a vehicle regardless of the insulator for supporting the pantograph 2.

FIG. 5 is a diagram for explaining a second arrangement example of the grounding device 15 according to the present embodiment.
In the example of FIG. 5, the grounding device 15 is disposed inside a special high voltage equipment frame 29 that accommodates special high voltage equipment such as the main circuit breaker 3 of the electric vehicle. The special high voltage equipment frame 29 is arranged in the electric vehicle or under the floor of the electric vehicle. In this example, the terminal plate 18 of the grounding device 15 is electrically connected to the input terminal of the main circuit breaker 3 to which the cable head 13b of the extra high voltage cable 12 is connected. The terminal plate 19 of the grounding device 15 is electrically connected to a grounding seat 27 attached to the special high voltage equipment frame 29 by a grounding wire 26A. The special high voltage equipment frame 29 is electrically connected to the vehicle body 11 by a ground wire 26B. Thereby, when the grounding device 15 is conducted, the circuit from the main circuit breaker 3 to the pantograph 2 can be grounded to the vehicle body 11.

  As shown in the example of FIG. 5, when the grounding device 15 according to the present embodiment is arranged inside the special high voltage equipment frame 29, a conventional mechanical protective grounding switch connected to the pantograph 2 is installed on the roof of the electric vehicle. It is also possible to install a mechanical protective grounding switch and the grounding device 15 according to the present embodiment. In the example of FIG. 5, the pantograph side of the main circuit breaker 3 inside the special high voltage equipment frame 29 in which the grounding device 15 is arranged is not exposed to the external environment. Small size adapted to the environment within.

  The grounding device 15 may be provided between the poles of the main circuit breaker 3. In this case, the ground side terminal plate 19 of the grounding device 15 does not necessarily need to be grounded to the vehicle body 11, and the primary winding 41 of the main transformer 4 is connected to the pantograph 2 via the grounding device 15 according to the present embodiment. It is good also as a structure connected with the side. Even with such a configuration, it is possible to perform grounding, and it is possible to discharge the residual charge accumulated in the device connected to the pantograph 2, and to prevent electric shock due to such residual charge.

  Note that a conventional mechanical grounding device using a mechanism such as a blade or a rod needs to secure an insulation distance between the tip of the blade and peripheral equipment, so that it is placed inside the special high-voltage equipment frame 29 or the like. It is difficult to place. On the other hand, in the grounding device 15 according to the present embodiment, the semiconductor switch is incorporated in the accommodating portion 21 that is an insulating cylinder, and there is no movable portion of a mechanism such as a blade outside thereof. It is also possible to provide it between the poles of the main circuit breaker 3 or arrange the tip of the cable head 13b of the extra high voltage cable 12 to be grounded to the vehicle body 11. Further, the posture of the grounding device 15 when the grounding device 15 is arranged is also arbitrary.

  In order to control the plurality of semiconductor switches 151, 152, 153, 154, and 155 constituting the grounding device 15 according to the above-described embodiment to the conductive state, it is necessary to input a control signal to each semiconductor switch from the outside. Here, the semiconductor switches 151, 152, 153, 154, and 155 that ground the conductive member such as the pantograph 2 having an extra high voltage to the vehicle body 11 are connected to the semiconductor switch 151 in which the extra high voltage applied thereto is connected in series. , 152, 153, 154, and 155 are applied, and the voltage applied to each semiconductor switch is obtained by multiplying the number of semiconductor switches between the terminal plate 18 and the terminal plate 19. Applied voltage. That is, the highest potential of the grounding device 15 as viewed from the ground potential of the vehicle body 11 is the same voltage as the extra high voltage supplied from the train line 1. For this reason, when a control signal for controlling conduction of the grounding device 15 is supplied from the drive circuit to the grounding device 15, it is necessary to ensure insulation between the control signal and the extra high voltage.

  However, the typical rating of the drive circuit itself is about 100V at the highest, and the withstand voltage is only about 2000V. For this reason, in order to ensure insulation between the control signal for controlling the conduction of the grounding device 15 and the extra high voltage applied to the grounding device 15, the wiring between the control signal and the portion to which the extra high voltage is applied is provided. It is necessary to set the distance to a creeping insulation distance far larger than the external size of the semiconductor switch. Therefore, it is difficult to directly connect the output of a normal drive circuit to each of the semiconductor switches 151, 152, 153, 154, and 155 to ensure insulation between the extra high voltage and the control signal. For this reason, as will be described below, in the drive circuit for driving the semiconductor switches 151, 152, 153, 154, and 155, a measure is required to ensure insulation between the extra high voltage and the control signal. .

FIG. 6 is a diagram illustrating an example of the configuration of the drive circuit 30 of the grounding device 15 according to the present embodiment.
The drive circuit 30 is for driving a plurality of semiconductor switches 151, 152, 153, 154, and 155 in response to a control signal SON supplied from a control circuit 31 on the vehicle side. In the example shown in FIG. 6, a configuration example of the drive circuit 30 using an insulation type transformer is shown as one method for ensuring insulation between the extra high voltage and the control signal. In the present embodiment, the grounding device 15 constitutes a vehicle grounding device together with the drive circuit 30 and the control circuit 31. However, the grounding device 15 may be a vehicle grounding device. Moreover, the application target of the grounding device 15 is not limited to a vehicle, and can be applied to any device.

  Schematically, the drive circuit 30 is cascade-connected to the plurality of semiconductor switches 151, 152, 153, 154, and 155, and supplies the induced voltage of the secondary winding to the control electrode of the corresponding semiconductor switch. A plurality of insulated transformers 321, 322,. In other words, the insulation type transformers 321, 322,..., 325 included in the drive circuit 30 have secondary windings corresponding to the plurality of semiconductor switches 151, 152, 153, 154, 155, respectively. The induced voltage of the secondary winding is supplied to the control electrode of the semiconductor switch. In this embodiment, the isolated transformer is such that the primary side winding and the secondary side winding are electrically insulated, and the primary side winding and the secondary side winding are magnetically coupled. Is meant to be.

  Specifically, the drive circuit 30 includes a plurality of insulated transformers 321, 322,..., 325 and a plurality of rectifiers 331, 332,. Of the plurality of subordinately connected insulated transformers 321, 322,..., 325, a control signal SON generated by the vehicle-side control circuit 31 is applied to the primary winding of the first-stage insulated transformer 321. Supplied. In the present embodiment, the control signal SON is an AC signal having a predetermined frequency.

  The primary winding of the second-stage insulated transformer 322 is connected to the secondary winding of the insulated transformer 321. The secondary side winding of the insulation type transformer 322 is connected to the primary side winding of a third stage insulation transformer (not shown), and the secondary side winding is connected to the fourth stage insulation (not shown). The primary winding of the side transformer is connected. The secondary winding of the fourth-stage insulated transformer (not shown) is connected to the primary winding of the fifth-stage insulated transformer 325 as the final stage.

  Each of the secondary windings of the plurality of insulated transformers 321, 322,..., 325 connected in cascade as described above is connected to each input section of the rectifiers 331, 332,. . Here, the plurality of rectifiers 331, 332,..., 335 rectify the output voltages of the plurality of insulated transformers 321, 322,..., 325 and control the plurality of semiconductor switches 151, 152, 153, 154, 155. It supplies to an electrode. Each of the output parts of the plurality of rectifiers 331, 332,..., 335 is connected to each control electrode of the plurality of semiconductor switches 151, 152,.

  Specifically, of the pair of output units of the rectifier 331, one output unit is connected to the gate of the IGBT constituting the semiconductor switch 151, and the other output unit of the pair of output units of the rectifier 331 is: It is connected to the emitter of the IGBT that constitutes the semiconductor switch 151. In addition, one of the pair of output units of the rectifier 332 is connected to the gate of the IGBT constituting the semiconductor switch 152, and the other output unit of the pair of output units of the rectifier 332 is the semiconductor switch 152. Is connected to the emitter of the IGBT constituting the. Similarly, one output unit of the pair of output units of the rectifier 335 is connected to the gate of the IGBT constituting the semiconductor switch 155, and the other output unit of the pair of output units of the rectifier 335 is The semiconductor switch 155 is connected to the emitter of the IGBT.

  In the example of FIG. 6, electrical insulation is secured for each of the semiconductor switches 151, 152,..., 155 by the insulating transformers 321, 322,. The AC voltage output from 325 is converted into a DC voltage by rectifiers 331, 332,..., 335, and control of semiconductor switches 151, 152,. Supply to the electrode. Thereby, the semiconductor switches 151, 152,..., 155 are based on the control signal SON applied to the primary side winding of the insulation type transformer 321 while ensuring the electrical insulation of each control signal with respect to the extra high voltage. It is possible to control the conduction state of the external.

  In this embodiment, the insulation type transformers 321, 322,..., 325 are electrically connected to a plurality of semiconductor switches 151, 152,. Since the purpose is to provide electrical insulation, the transformation ratio may be 1: 1, for example. Here, it is assumed that the control circuit 31 operates with a general 100V alternating current. For example, the power supply voltage on the vehicle side, the control power supply of the control circuit of the semiconductor switches 151, 152,. Depending on the specifications of the rectifiers 331, 332,..., 335, the respective transformation ratios of the insulated transformers 321, 322,.

  In the present embodiment, for simplification of description, control signals SG1L, SG1H, SG2L, SG2H,..., SG5L, SG5H output from the rectifiers 331, 332,. Although it supplies directly to 152, ..., 155, generally the control board etc. for controlling semiconductor switch 151,152, ..., 155 are connected to the control electrode of each semiconductor switch. Accordingly, the outputs of the rectifiers 331, 332,..., 335 are supplied to the control board of such a semiconductor switch. However, if the semiconductor switch has a specification that does not require a control board, the output of each rectifier may be supplied directly to the control electrode of the semiconductor switch.

  6, five rectifiers 331, 332,..., 335 corresponding to five semiconductor switches 151, 152,..., 155 and five insulated transformers 321, 322,. 325, the number of rectifiers and the number of isolated transformers can be arbitrarily set according to the number of semiconductor switches. Further, when the specifications of the semiconductor switches 151, 152,..., 155 allow an AC signal as a control signal supplied to the control electrode, the rectifiers 331, 332,. it can.

First Modified Example of Drive Circuit FIG. 7 is a diagram showing a configuration of a drive circuit 30A according to a first modified example of the grounding device 15 according to the present embodiment.
The drive circuit 30A shown in FIG. 7 has the same configuration as the drive circuit 30 shown in FIG. 6 described above, but the primary windings of the insulated transformers 321, 322,. A control signal is commonly applied from the control circuit 31 to the secondary winding.

  According to the first modification, the difference in signal transmission time from the control circuit 31 to each control electrode of the plurality of semiconductor switches 151, 152,..., 155 can be shortened. A state in which an excessive voltage is intensively applied to each semiconductor switch can be relaxed. However, in the first modification, it is necessary that the insulation type transformer has a withstand voltage that can insulate the primary side and the secondary side against the extra high voltage.

Second Modified Example of Drive Circuit FIG. 8 is a diagram showing a configuration of a drive circuit 30B according to a second modified example of the grounding device 15 according to the present embodiment.
The drive circuit 30B shown in FIG. 8 includes an insulated transformer 320 in place of the insulated transformers 321, 322,... 325 in the configuration of the drive circuit 30A according to the first modification shown in FIG. Yes. The insulated transformer 320 includes a core 3202 in which a plurality of secondary windings 32021, 32022,..., 32025 and a single primary winding 3201 corresponding to the plurality of semiconductor switches 151, 152,. It has a structure magnetically coupled via. For example, the primary winding 3201 is desirably disposed at a position facing the secondary winding 32021 provided corresponding to the ground-side semiconductor switch 151. However, the position between the primary side winding 3201 and the secondary side windings 32021, 32022,..., 32025 as long as electrical insulation between the primary side and the secondary side can be ensured. The relationship is arbitrary.

According to the second modification, the number of primary windings can be reduced as compared with the drive circuit 30A of the first modification, so that the configuration of the drive circuit 30B can be simplified. Further, similarly to the first modification, a plurality of semiconductor switches 151, 152,..., 155 can be made conductive at the same time, and the state where an excessive voltage is intensively applied to each semiconductor switch can be relaxed.
In this embodiment, the drive circuits 30, 30A, and 30B shown in FIGS. 7, 8, and 9 are provided in the grounding device 15, but the drive circuits 30, 30A, and 30B are connected to an external vehicle. As a component of the control circuit on the side, it may be excluded from the components of the grounding device 15.

(Explanation of circuit operation)
Next, the operation of the grounding device 15 according to the present embodiment will be described.
Here, the grounding device 15 will be described as including the drive circuit 30 of FIG.
During normal operation of the electric vehicle, the control signal SON is not supplied from the vehicle side. In this case, since the primary side winding of the insulation type transformer 321 of the drive circuit 30 is not energized, no voltage is induced in the secondary side windings of the plurality of insulation type transformers 321, 322,. For this reason, a potential difference does not occur between the emitter and gate of the IGBT constituting the semiconductor switches 151, 152,..., 155, and these semiconductor switches are rendered non-conductive. Accordingly, the pantograph 2 is not grounded to the vehicle body 11, and the pantograph 2 and the vehicle body 11 are electrically insulated.

  Next, for example, when the pantograph 2 is grounded to the vehicle body 11 for the purpose of ensuring safety during maintenance work, for example, the control circuit 31 on the vehicle side outputs a control signal SON by the operator's operation, and the drive circuit is generated by the control signal SON. When the primary side windings of the 30 isolation transformers 321 are excited, an AC voltage is induced in the secondary side windings of the isolation transformers 321, 322,. Each of the rectifiers 331, 332,..., 335 rectifies the AC voltage induced in the secondary winding of each of the isolated transformers 321, 322,..., 325, and sends the control signals SG 1 L, SG 1 H to the respective semiconductor switches 151. , 152,..., 155 are supplied to control electrodes (emitter and gate). Thereby, each semiconductor switch 151,152, ..., 155 is conducted.

  As described above, when the semiconductor switches 151, 152,..., 155 are turned on, the pantograph 2 is grounded to the vehicle body 11 through the grounding device 15. When the control signal SON from the outside disappears, the semiconductor switches 151, 152,... 155 are turned off again, and the grounding device 15 returns to the insulated state, so that the pantograph 2 is electrically insulated from the vehicle body 11. The pantograph 2 is not grounded. During the period when the external control signal SON is generated, the semiconductor switches 151, 152,..., 155 are kept in a conductive state, and the grounding device 15 functions.

  Here, since the grounding device 15 of this embodiment is composed of the semiconductor switches 151, 152,..., 155, it does not require operating air unlike a grounding device using a conventional cylinder or the like. Since the conventional grounding device cannot move the cylinder for moving the blade without air for operation, it cannot be grounded and connected to the ground equipment or other vehicles by connecting an air hose or the like. It is necessary to supply air, or to secure the air by operating the compressor of the vehicle by supplying power from a storage battery mounted on the vehicle or power from the ground equipment, and wait until the blade is at an operable pressure. On the other hand, the grounding device 15 of the present embodiment can be grounded as long as there is a control power supply for conducting the semiconductor switches 151, 152,... 155 even when there is no air for operation. The control power supply for conducting the semiconductor switch may be a storage battery mounted on the vehicle or an external power supply by power supply from the ground facility.

According to the present embodiment, for example, when the grounding is intended to discharge the charge of the charged device, for example, during maintenance work, or to protect the worker when pressurized. Since it is not necessary to pass a large current through the semiconductor switch, the grounding device 15 can be used repeatedly even when a semiconductor switch having a small current carrying capacity is used.
As means for reducing the short-circuit current, means for inserting a reactor on the primary side is known. If a reactor is installed on the side of the train line and the substation detection device assumes that the train line is grounded and optimally controls the flow time and current to stop feeding, the semiconductor switch will not be damaged. It is also possible to realize a function as a grounding device for stopping feeding.

Next, a modified example of the grounding device of the present embodiment will be described.
FIG. 9 is a diagram schematically illustrating an example of the configuration of a grounding device 15A according to a modification of the present embodiment. FIG. 10 is a cross-sectional view of a grounding device 15A according to a modification of the embodiment, and schematically shows a structure in a cross section orthogonal to the longitudinal direction of the grounding device 15A.
A grounding device 15A shown in FIG. 9 is the same as the grounding device 15 shown in FIG. 2 described above, but instead of the semiconductor switches 151, 152, 153, 154, and 155, an optical direct ignition thyristor (optical direct ignition semiconductor switch) 151A, 152A, 153A, 154A, 155A.

  Specifically, the grounding device 15A includes a terminal plate 18, a terminal plate 19, and a plurality of optical direct ignition thyristors 151A, 152A, 153A, 154A, 155A connected in series, and the optical direct ignition thyristor. Optical fibers F1, F2, F3, F4, and F5 are connected to the gate terminals (control electrodes) of 151A, 152A, 153A, 154A, and 155A. In this modification, as a component corresponding to the drive circuits 30, 30A, and 30B shown in FIGS. 6, 7, and 8, respectively, a plurality of light direct firing thyristors 151A, 152A, 153A, A drive circuit for driving 154A and 155A is provided.

  The drive circuit in this modification is a light supply means for supplying light to each control electrode of the direct light ignition thyristor, and a light emitting element for converting the control signal SON output from the control circuit 31 into an optical gate signal. A gate generation circuit (not shown) is provided. This gate generation circuit is provided corresponding to the plurality of light direct firing thyristors 151A, 152A, 153A, 154A, and 155A, and supplies a light gate signal to the control electrode of the corresponding light direct firing thyristor. The light direct firing thyristors 151A, 152A, 153A, 154A, and 155A are controlled by the control circuit 31 to emit light from the light emitting elements of the gate generation circuit (not shown) through the optical fibers F1, F2, F3, F4, and F5. When a gate signal is supplied, a conductive state can be obtained. Note that the gate generation circuit described above may be provided as a component of the control circuit 31.

  With this configuration, when the pantograph 2 is grounded to the vehicle body 11, an optical gate signal corresponding to the control signal SON described above is output from the vehicle-side control circuit 31, and this optical gate signal is optically directly transmitted. By supplying to the gate terminals of the starting thyristors 151A, 152A, 153A, 154A, and 155A, the optical direct starting thyristors 151A, 152A, 153A, 154A, and 155A are made conductive. When the light direct firing thyristors 151A, 152A, 153A, 154A, 155A are turned on, the pantograph 2 can be grounded to the vehicle body 11 through the ground circuit 15A, and the same effects as in the above-described embodiment can be obtained. . Further, by providing a gate signal by light, the optical direct firing thyristors 151A, 152A, 153A, 154A, and 155A can be brought into a conductive state. For this reason, a gate including an insulating transformer as shown in FIG. A drive power supply is not required, and the grounding device can be configured with a simple configuration.

Further, when the optical direct firing thyristors 151A, 152A, 153A, 154A, 155A are used, if insulation of the optical fibers F1, F2, F3, F4, F5 is necessary, as shown in FIG. 10, the optical fiber F1 , F2, F3, F4, and F5 are passed through the insulating housing 21 and connected to the gate terminals of the direct light ignition thyristors 151A, 152A, 153A, 154A, and 155A, thereby insulating against high voltage. be able to.
Note that the number of direct light ignition thyristors constituting the grounding device 15A can be arbitrarily set.

Next, an example of the control circuit 31 will be described.
FIG. 11 is a diagram illustrating an example of the configuration of the control circuit 31 of the grounding device according to the embodiment.
In the example shown in FIG. 11, the grounding device 15 is switched between the non-grounding state and the grounding state in conjunction with the state of the pantograph 2 and the main circuit breaker 3 of the electric vehicle. For example, if the grounding device of this embodiment is grounded before the pantograph 2 is sufficiently away from the train line 1, the train line 1 may be inadvertently grounded. Here, a description will be given of a configuration example in which the grounding device 15 is changed from an insulated state to a grounded state after detecting that the pantograph 2 is lowered for ensuring safety in maintenance work or the like. In the present embodiment, the rise of the pantograph 2 is detected, but the pantograph rise detection device is disclosed in, for example, Japanese Patent Publication Nos. 04-70849 and 04-72442.
In the present embodiment, the control circuit 31 is provided on the vehicle side, but may be provided as a component of the grounding device 15.

  The control circuit 31 includes a power line 41, a control power source (storage battery) 49, pantograph rise detection switches 43a and 43b, main circuit breaker detection switches 3a, 3b and 3c, a normally closed switch 48b, an excitation coil 45, a normally open switch 45a, a normal circuit. A closing switch 45b, a pantograph raising operation switch 47, an exciting coil 50, a normally open switch 50a, a normally open switch 50aa, an exciting coil 48, and a diode 44 are provided.

  Here, the exciting coil 45, the normally open switch 45a, and the normally closed switch 45b constitute a relay for grounding command. Further, the exciting coil 48 and the normally closed switch 48b constitute a relay for controlling the operation of the ground command relay. The exciting coil 50 and the normally open switch 50a constitute a self-holding circuit that self-holds the closed state. The normally open switch 50 a is connected in parallel with a pantograph raising operation switch 47 for electrically connecting the pantograph 2 to the train line 1. The exciting coils 461 and 462 are exciting coils of an electromagnetic valve that controls the rise / fall of the pantograph, and are not direct components of the control circuit 31.

  The pantograph rise detection switches 43a and 43b are in a closed state when the pantograph 2 that is a current collector of the electric vehicle is not electrically connected to the train line 1. The two pantograph rise detection switches 43 a and 43 b are assumed to have two pantographs, but the number thereof is arbitrarily set according to the number of pantographs 2. The main circuit breaker detection switches 3a, 3b, 3c are closed when the main circuit breaker 3 for cutting off the electric power supplied from the train line 1 is in the cut-off state. The three main circuit breaker detection switches 3 a, 3 b, and 3 c are assumed to have three main circuit breakers, but the number thereof is arbitrarily set according to the number of main circuit breakers 3.

  The normally open switch 45a includes pantograph rise detection switches 43a and 43b and a main circuit breaker between a power supply line 41 to which a voltage of a predetermined control power supply 49 is applied and an input portion of the drive circuit 30 to which a control signal SON is applied. The detection switches 3a, 3b, and 3c are connected in series. The normally closed switch 48b is for energizing the exciting coil 45 of the normally open switch 45a to close the normally open switch 45a when the normally closed switch 48b is in the closed state. The self-holding circuit composed of the exciting coil 50 and the normally open switch 50a is such that when the pantograph raising operation switch 47 is operated, the normally open switch 50a is closed and the closed state is self-held.

  When the pantograph raising operation switch 47 is operated, the normally open switch 50aa is closed in conjunction with the normally open switch 50a and energizes the exciting coil 48 of the normally closed switch 48b to open the normally closed switch 48b. It is to make. The normally closed switch 45b is closed in conjunction with the normally open switch 45a when the normally open switch 45a is opened, and the exciting coils 461 and 462 of the pantograph lift / descent control solenoid valve are closed. Is to energize.

  According to the control circuit 31 having the above-described configuration, for example, when the operation of the electric vehicle is finished, when all the pantographs 2 are lowered and all the main circuit breakers are in the cut-off state, the control signal SON is generate. That is, when the electric vehicle has a long formation, a plurality of pantographs 2 and main circuit breakers 3 are mounted, and a state in which some of the pantographs 2 are lowered is a normal state in which no power is received. Therefore, in the control circuit 31, all the normally closed switches (b contacts) of the pantograph rising detection switches 43a, 43b and the main breaker detecting switches 3a, 3b, 3c are connected in series, and all the pantographs 2 are lowered. And detecting that all the main circuit breakers 3 are open. Then, on the condition that all the pantographs are lowered and all the main circuit breakers are opened, a control signal SON for grounding is sent to the grounding device 15 of the present embodiment, and grounded.

  According to the configuration of the control circuit 31 in FIG. 11, the normally closed switch 48b is in the closed state in the initial state where the pantograph raising operation switch 47 is not operated. For this reason, the exciting coil 45 is energized and the normally open switch 45a is in a closed state. Therefore, if the above conditions are satisfied, that is, if all of the pantograph rise detection switches 43a, 43b and the main circuit breaker detection switches 3a, 3b, 3c are in the closed state, the voltage of the control power source 49 detects the pantograph rise detection. The control signal SON is applied to the input part of the drive circuit 30 of the grounding device 15 through the switches 43a, 43b, the main circuit breaker detection switches 3a, 3b, 3c, and the normally open switch 45a. However, since the control power supply 49 is a DC power supply in the example of FIG. 11, the voltage supplied from the control power supply 49 is converted into an AC signal to be a control signal SON and supplied to the drive circuit 30.

  As described above, for example, when the pantograph 2 is lowered at the end of the operation of the electric vehicle and the main circuit breaker 3 is interrupted, the main circuit breaker detection switches 3a, 3b, 3c and the main circuit breaker detection switches 3a, 3b, 3c are Since it is in the closed state, the pantograph 2 is automatically grounded to the vehicle body by the grounding device 15. Therefore, when the maintenance inspection work is performed after the operation of the electric vehicle is completed, the pantograph 2 is grounded and discharged from the vehicle body 11, so that the operator does not get an electric shock and can work safely. It can be carried out.

  Here, if the pantograph 2 is raised while the grounding device 15 is in the grounded state, the feeding is unnecessarily stopped. In order to avoid such a situation, it is necessary to prohibit the rise of the pantograph 2 while the control signal SON is output to the grounding device 15. For this reason, the normally closed switch 45b (b contact) inserted in series with the excitation coils 461 and 462 of the pantograph ascending solenoid valve prohibits energization of the excitation coils 461 and 462 of the pantograph ascending / descending control solenoid valve. doing.

  In the present embodiment, the control circuit 31 continues to output the control signal SON to the grounding device 15 until the control power supply 49 is cut off unless the pantograph raising operation switch 47 is operated. Therefore, in order to place the grounding device 15 in the ungrounded state without raising the pantograph 2, for example, the circuit breaker is connected in series with the main circuit breaker detection switches 3a, 3b, 3c and the main circuit breaker detection switches 3a, 3b, 3c. (Not shown) may be provided to open the circuit breaker.

Next, an operation in a case where the electric vehicle is in a driving state and the panda graph 2 is raised will be described.
For example, when the operator of the electric vehicle depresses the pantograph raising operation switch 47, the exciting coil 50 is energized, and thereby the normally open switches 50a and 50aa are closed. Here, when the normally open switch 50a is closed, a path from the control power source 49 to the ground through the normally open switch 50a and the exciting coil 50 is formed. For this reason, after that, even if the pantograph raising operation switch 47 is opened, the exciting coil 50 is self-held in the closed state.

  When the normally open switch 50a is self-held in the closed state, the exciting coil 50 is maintained in the energized state, so that the normally open switch 50aa is maintained in the closed state. For this reason, the exciting coil 48 is maintained in a state of being energized by the normally open switch 50aa. When the excitation coil 48 is energized, the normally closed switch 48b is opened, and the energization of the excitation coil 45 is stopped. For this reason, the normally open switch 45a is opened, and the normally closed switch 45b is closed.

  When the normally open switch 45a is in the open state, the signal path between the power supply line 41 and the input part of the drive circuit 30 is cut off, so that the control signal SON disappears. As a result, the grounding device 15 is not grounded. Further, when the normally closed switch 45b is closed, the exciting coils 461 and 462 are energized. For this reason, the solenoid valve which controls the rise / fall of the pantograph is activated, and the pantograph 2 is raised. As described above, the grounding device 15 is brought into a non-grounding state, the pantograph 2 is raised, and power is supplied from the train line.

  In the configuration of FIG. 11, when the grounding device 15 is operated as a conventional protective ground switch, the protective ground signal SEGS used for conducting the conventional ground protective switch is supplied via the diode 44 to the drive circuit 30. To supply. In this case, the protective ground signal SEGS is converted into an AC signal and supplied as a control signal SON to the input portion of the drive circuit 30 (primary winding of the insulation transformer 321). As a result, the grounding device 15 is grounded as described above, and the pantograph 2 is grounded to the vehicle body 11.

  According to the control circuit 31, the pantograph 2 is grounded to the vehicle body 11 by the grounding device 15 after the pantograph 2 is lowered by the normal operation at the end of the operation of the electric vehicle without requiring any special operation. The electric charge of the main circuit which may remain can be automatically discharged. Therefore, it is possible to ensure the safety of the operator such as maintenance and inspection.

According to the grounding device and the vehicle grounding device of at least one embodiment described above, a grounding device having excellent maintainability can be realized by using the semiconductor switch.
Further, for example, as illustrated in FIG. 4, by incorporating the grounding device 15 inside the insulator or the like that supports the pantograph 2, the conductive portion of the grounding device that is conventionally exposed on the roof of the electric vehicle is protected from the external environment. I can do it. Therefore, even if it is arranged in an exposed state on the roof of the electric vehicle, it can be stably operated without being stopped due to freezing or the like. Further, it is not necessary to strengthen measures against waterproofing and flooding unlike conventional devices, and measures against freezing and condensation are not necessary. In addition, since the number of protrusions on the vehicle roof can be reduced, noise can be reduced.

Further, unlike the conventional protective grounding switch using air for operation, compressed air or the like for operating the cylinder is not required, and if the power source can be secured, the grounding operation can be performed.
Furthermore, since the grounding device 15 is a non-contact type, there is no response delay of the cylinder using the working air as compared with the conventional protective grounding switch using the working air. For this reason, the time until the pantograph is brought into contact with the vehicle body can be greatly reduced. Therefore, the pantograph can be grounded immediately, and a grounding device with excellent responsiveness can be realized. Thereby, for example, in a vehicle traveling at a high speed, it is possible to shorten the idle travel distance.

  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 ... Train line 2 ... Pantograph 3 ... Main circuit breaker 4 ... Main transformer 5 ... Grounding mechanism 6 ... Rail 7a, 7b ... Power converter 8 ... Main motor 9 ... Auxiliary rotating machine 10 ... Lightning arrester 11 ... Car body 12 ... Special high voltage Cable 13a, 13b ... Cable head 14 ... Grounding terminal block 15, 15A ... Grounding device 18, 19 ... Terminal board 20 ... Seat for wiring 21 ... Housing part 22a, 22b ... Spacer 23, 24 ... Sealing part 25 ... Insulator 26 ... Grounding wire 27 ... Grounding seat 28 ... Conductor 29 ... Special high voltage equipment frame 30, 30A, 30B ... Drive circuit 31 ... Control circuit 151-155 ... Semiconductor switch 151A-155A ... Optical direct firing thyristor 320, 321-325 ... Insulation Type transformer 331-335 ... rectifier

Claims (9)

A first terminal electrically connected to a conductive member that becomes a high voltage;
A second terminal electrically connected to a conductive member having a predetermined potential on the ground side;
A plurality of semiconductor switches connected in series between the first terminal and the second terminal and having a first main electrode, a second main electrode, and a control electrode;
A grounding device. A drive circuit for driving the plurality of semiconductor switches in response to a control signal;
The drive circuit is
2. The device according to claim 1, further comprising a plurality of insulated transformers connected to the plurality of semiconductor switches and supplying an induced voltage of the secondary winding to a control electrode of the corresponding semiconductor switch. Grounding equipment. A drive circuit for driving the plurality of semiconductor switches in response to a control signal;
The drive circuit is
An insulating transformer having a secondary winding corresponding to the plurality of semiconductor switches and supplying an induced voltage of the secondary winding to a control electrode of the corresponding semiconductor switch is provided. The grounding device according to claim 1. The plurality of semiconductor switches are optical direct ignition semiconductor switches, further comprising a drive circuit for driving the plurality of semiconductor switches in response to a control signal;
The drive circuit is
2. The grounding device according to claim 1, further comprising light supply means connected to the plurality of semiconductor switches and supplying light to the control electrodes of the corresponding semiconductor switches. An insulating housing for housing the plurality of semiconductor switches arranged in a row;
A conductive first sealing portion that seals one opening of the housing portion in a state of being electrically connected to one end of a switch formed of an assembly of the plurality of semiconductor switches;
A conductive second sealing portion that seals the other opening of the housing portion in a state of being electrically connected to the other end of the switch formed of an assembly of the plurality of semiconductor switches;
Further comprising
5. The grounding device according to claim 1, wherein the first sealing portion forms the first terminal, and the second sealing portion forms the second terminal. 6.   The grounding device according to claim 5, wherein the housing portion is a cylindrical body made of porcelain or a polymer insulating material.   The grounding device according to claim 5, wherein the housing portion is a hollow insulator that supports a current collector of a vehicle, and the plurality of semiconductor switches are housed inside the insulator.   The grounding device according to claim 5, wherein the grounding device is installed inside a frame that accommodates the special high-voltage equipment of the vehicle. In addition to the first terminal, the second terminal, the plurality of semiconductor switches, and the drive circuit provided in the grounding device according to any one of claims 2 to 4, further comprising a control circuit,
The conductive member that becomes high voltage is a member that constitutes a current collector of an electric vehicle that travels by receiving the high voltage from a train line, and the member that becomes the predetermined potential on the ground side is a vehicle body of the electric vehicle And
The control circuit includes:
A first detection switch that is closed when the current collector of the electric vehicle is not electrically connected to the train line;
A second detection switch that is closed when a circuit breaker for cutting off power supplied from the train line is in a cut-off state;
A first normally open switch connected in series with the first detection switch and the second detection switch between a power supply line to which a predetermined power supply voltage is applied and an input of the drive circuit to which the control signal is applied; ,
A first normally closed switch that energizes the exciting coil of the first normally open switch to close the first normally open switch when in the closed state;
A second normally open switch connected in parallel with an operation switch for electrically connecting the current collector to the train line, and the second normally open switch is closed when the operation switch is operated; A self-holding circuit that self-holds the closed state of the second normally open switch;
When the operation switch is operated, a third state is established in which the first normally closed switch is opened by energizing the exciting coil of the first normally closed switch in a closed state in conjunction with the second normally open switch. A normally open switch,
A second normally closed switch that is closed in conjunction with the first normally open switch and energizes the exciting coil of the current collector drive solenoid valve when the first normally open switch is in an open state;
A vehicle grounding device.

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