JP7309633B2 - Rail-to-ground voltage suppression system - Google Patents

Description

The present invention relates to rail-to-ground voltage suppression systems.

In an electric railway, a substation, which is a power source, and a vehicle, which is a load, are connected to each other with an overhead wire as a positive electrode and a rail as a negative electrode to form an electric circuit, thereby supplying the electric power necessary for running the vehicle. That is, when the vehicle is running, current flows from the substation to the vehicle through the catenary, which is the positive electrode, and current flows from the vehicle to the substation through the rail, which is the negative electrode (return current).

Along with the return current, a voltage drop occurs on the rail between the substation and the rolling stock, and a potential difference (rail-to-ground voltage) occurs between the rail and the ground, which is the potential reference, according to the distribution of the voltage drop over the entire line. . Excessive rail-to-ground voltage poses a risk of electric shock when wayside workers touch the rail, so in recent years it has become necessary to keep the rail-to-ground voltage within a specified range, as indicated by the international standard IEC62128. (See Non-Patent Documents 1 to 3).

For example, as disclosed in Patent Document 1, as a countermeasure against excessive rail-to-ground voltage, a short-circuit switch is provided between the rail and ground, and when a rail-to-ground voltage exceeding a predetermined value is detected, the rail and ground are short-circuited. , a device (VLD: Voltage Limiting Device) that suppresses the rail-to-ground voltage by equipotentializing the rail and the ground is introduced.

JP 2018-185284 A

IEC62128-1:2013.Railway applications- Fixed installations - Electrical safety, earthing and the return circuit - Part 1: Protective provisions against electric shock. IEC62128-2:2013.Railway applications- Fixed installations - Electrical safety, earthing and the return circuit - Part 2: Provisionsagainst the effects of stray currents caused by d.c. traction systems. IEC62128-3:2013.Railway applications- Fixed installations - Electrical safety, earthing and the return circuit - Part 3: Mutual interaction of a.c. and d.c. traction systems.

However, in the conventional configuration in which the VLD is installed as in Patent Document 1, although the rail-to-ground voltage near the VLD is suppressed, the variation in the rail-to-ground voltage at the operating position of the VLD spreads over the entire line, However, there is a problem that an excessive rail-to-ground voltage is generated secondarily.

The present invention has been made in consideration of the above points, and suppresses the occurrence of an excessive rail-to-ground voltage far from the VLD due to the fluctuation of the rail-to-ground voltage at the operating position of the VLD spreading over the entire line. One purpose is to

In order to solve the above problems, in one aspect of the present invention, a rail-to-ground voltage suppression system for an electric railway is provided, upon detecting that the rail-to-ground voltage at an operating position deviates from an allowable range, suppressing the rail at the operating position. a first switch for short-circuiting and grounding; and a second switch for switching the rail, in which the insulating portion is inserted into the rail joint, between an insulating state at the insulating portion and a conducting state across the insulating portion. and, when the first switch short-grounds the rail, the second switch switches the rail to an isolated state.

According to the present invention, for example, it is possible to suppress the occurrence of an excessive rail-to-ground voltage far from the VLD due to the fluctuation of the rail-to-ground voltage at the operating position of the VLD spreading over the entire line.

It is a figure for demonstrating the subject of a prior art. 1 is a configuration diagram of a rail-to-ground voltage suppression system according to Embodiment 1 of the present invention; FIG. 1 is a configuration diagram of a VLD according to Embodiment 1 of the present invention; FIG. FIG. 4 is a configuration diagram of another example of the VLD according to Embodiment 1 of the present invention; 1 is a configuration diagram of a rail insulating device according to Embodiment 1 of the present invention; FIG. FIG. 4 is a configuration diagram of another example of the rail insulating device according to Embodiment 1 of the present invention; It is a figure for demonstrating the effect|action of Embodiment 1 of this invention. FIG. 4 is a configuration diagram of a rail-to-ground voltage suppression system according to Embodiment 2 of the present invention; FIG. 5 is a configuration diagram of a rail insulating device according to Embodiment 2 of the present invention; It is a figure for demonstrating the effect|action of Embodiment 2 of this invention. FIG. 3 is a configuration diagram of a rail-to-ground voltage suppression system according to Embodiment 3 of the present invention; FIG. 7 is a configuration diagram of a rail insulating device according to Embodiment 3 of the present invention; It is a figure for demonstrating the effect|action of Embodiment 3 of this invention. FIG. 4 is a configuration diagram of a rail-to-ground voltage suppression system according to Embodiment 4 of the present invention; FIG. 5 is a configuration diagram of a rail insulating device according to Embodiment 4 of the present invention;

Preferred embodiments of the present invention are described below. In the following, the same or similar elements and processes are denoted by the same reference numerals, differences are explained, and overlapping explanations are omitted. Further, in the embodiments described later, the differences from the previously described embodiments will be described, and redundant description will be omitted.

In addition, the configuration and processing shown in the following description and drawings are intended to illustrate the outline of the embodiments to the extent necessary for understanding and implementing the present invention, and are intended to limit the embodiments according to the present invention. not intended to do so. Moreover, each embodiment and each modification can be combined in whole or in part without departing from the gist of the present invention and within a matching range.

In addition, "top", "bottom", "left", and "right" used in the following description indicate relative directions when viewed from the drawing.

<Problem of conventional technology>
Prior to describing the embodiments, the problems of the prior art will be described. FIG. 1 is a diagram for explaining the problem of the conventional technology. FIG. 1 shows an overview of a rail-to-ground voltage suppression system S according to the prior art. A conventional rail-to-ground voltage suppression system S includes a vehicle 1A, a power source 2, an overhead wire 3, a rail 4, a ground 5, and a VLD 6.

The vehicle 1A and the power source 2 are connected to an overhead wire 3 and a rail 4, respectively. Electric power is supplied from the power source 2 to the vehicle 1A by current flowing through the overhead wire 3 as the positive electrode and the rail 4 as the negative electrode. Rail 4 is connected to ground 5 through VLD6. VLD 6 shorts rail 4 and ground 5 when a voltage exceeding a predetermined value occurs between rail 4 and ground 5 .

As shown in the lower diagram of FIG. 1, at the operating position p0 of the VLD 6, the rail-to-ground voltage is V1, which is out of the allowable range. Therefore, when the VLD 6 is operated to reduce the rail-to-ground voltage at the operating position p10 to 0, the rail-to-ground voltage is similarly suppressed at positions other than the operating position p0. Therefore, as shown in the lower diagram of FIG. 1, there is a problem that the rail-to-ground voltage beyond the position p1 with respect to the operating position p0 deviates from the allowable range and becomes excessive.

[Embodiment 1]
<Configuration of rail-to-ground voltage suppression system 1S according to Embodiment 1>
FIG. 2 is a configuration diagram of the rail-to-ground voltage suppression system 1S according to Embodiment 1 of the present invention. The rail-to-ground voltage suppression system 1S is different from the prior art rail-to-ground voltage suppression system S of FIG. The rail insulating device 7 receives an opening command 8 output from the VLD 6, and electrically divides the rail 4 in the traveling direction of the vehicle 1A with the installation position of the rail insulating device 7 as a boundary, and separates the divided rails 4 from each other. Insulate. This is hereinafter referred to as "insulation of rail 4".

The VLD 6, as shown in FIG. 3A, includes a normally open shorting switch 201 between rail 4 and ground 5, and a voltmeter 202 observing the voltage between rail 4 and ground 5 has a predetermined value. When the value exceeds the value, the comparator 203 outputs a closing command and the short-circuit switch 201 is closed. When the short-circuit switch 201 is turned on, the open command 8 is output. As shown in FIG. 3B, which is another example of the configuration of the VLD 6, the closing command for the short-circuit switch 201 may be output as the opening command 8. FIG.

<Configuration of Rail Insulating Device 7 According to Embodiment 1>
FIG. 4A is a configuration diagram of the rail insulating device 7 according to Embodiment 1 of the present invention, showing the structure of the rail 4 and the rail insulating device 7 viewed from above in FIG. As shown in FIG. 4A, two rails 4 are laid in parallel, and by inserting an insulation joint 301 into each of the two rails 4, the rails 4 are insulated with the insulation joint 301 as a boundary. . The rail 4 insulated with the installation position of the insulating joint 301 as a boundary is connected to the circuit breaker 303 via the jumper wire 302, so that the state of the rail 4 can be changed between the insulating state at the insulating joint 301 and the state across the insulating joint 301. It is possible to switch between the conductive state and the conductive state. The circuit breaker 303 is normally closed, and is opened when the opening command 8 is received to put the rail 4 in an insulated state.

When transmitting a security signal such as an on-track detection signal to the rail 4, as shown in FIG. By connecting to a circuit breaker 303 via a jumper wire 302, the rail 4 can be switched between an insulated state and a conductive state with the installation position of the insulated joint 301 as a boundary.

Note that the circuit breaker 303 can be replaced with any switch that can switch between an insulating state and a conducting state, such as a disconnector or a contactor.

<Effect of Embodiment 1>
FIG. 5 is a diagram for explaining the action of Embodiment 1 of the present invention. According to this embodiment, when the rail-to-ground voltage at the operating position p10 of the VLD 6 deviates from the allowable range, the VLD 6 is closed and the rail-to-ground voltage at the operating position p10 becomes zero. As the VLD 6 is turned on, an open command 8 is output to the rail insulating device 7 . The rail insulator 7 to which the open command 8 is input insulates the rail 4 . As a result, the rail 4 is divided into a grounded system and a non-grounded system with the installation position p11 of the rail insulating device 7 as a boundary. In the grounded system, the rail-to-ground voltage is reduced to the 0 starting point at the operating position p10 of VLD 6, while in the ungrounded system the state before VLD 6 is turned on is maintained.

As described above, according to the present embodiment, it is possible to limit the influence range of the variation of the rail-to-ground voltage at the operating position of the VLD 6 and suppress the increase in the rail-to-ground voltage far from the VLD 6 .

[Embodiment 2]
<Configuration of rail-to-ground voltage suppression system 2S according to Embodiment 2>
FIG. 6 is a configuration diagram of a rail-to-ground voltage suppression system 2S according to Embodiment 2 of the present invention. The rail-to-ground voltage suppression system 2S differs from the rail-to-ground voltage suppression system 1S according to the first embodiment in that a plurality of rail insulating devices 7 are provided. Individual installations are identified by a code suffix.

VLD 6 outputs open command 8 to two adjacent rail insulators 7 . For example, as in VLD 6i, when rail insulating devices 7k-1 and 7k are arranged on both the left and right sides of the device as viewed in FIG. 7k-1 and 7k are output. Further, when focusing on the rail insulating device 7, for example, the rail insulating device 7k has VLDs 6i and 6i+1 arranged on both the left and right sides thereof, respectively, as viewed in FIG. receive.

By arranging the VLD 6 and the rail insulating device 7 in this manner, a plurality of opening commands 8 are input to one rail insulating device 7 . In a configuration in which a plurality of opening commands 8 are input, the rail insulating device 7 operates to insulate the rail 4 when at least one or more opening commands 8 are input.

<Configuration of Rail Insulating Device 7 According to Second Embodiment>
FIG. 7 is a configuration diagram of a rail insulating device 7 according to Embodiment 2 of the present invention. 7, the input/output to/from the rail insulating device 7 will be described using the rail insulating device 7k of FIG. 6 as an example.

The rail insulating device 7k receives the open command 8i from the VLD 6i located on the left side and the open command 8i+1 from the VLD 6i+1 located on the right side. When receiving one of the opening commands, the rail insulating device 7 k generates an opening command 8 ′ using the OR circuit 601 and inputs the opening command 8 ′ to the breaker 303 to open the breaker 303 .

<Effect of Embodiment 2>
FIG. 8 is a diagram for explaining the action of Embodiment 2 of the present invention. FIG. 8 shows an example in which an excessive rail-to-ground voltage is detected at the leftmost VLD 6i-1.

According to this embodiment, for example, when the rail-to-ground voltage at the operating position p20 of the VLD 6i-1 deviates from the allowable range, the VLD 6i-1 is closed and the rail-to-ground voltage at the operating position p20 becomes zero. As the VLD 6i-1 is turned on, an open command 8i-1 is output to the rail insulating device 7k-1 at the installation position p21 closest to the operating position p20. The rail insulating device 7k-1 insulates the rail 4 when the open command 8i-1 is input. As a result, the rail 4 is divided into a grounded system and a non-grounded system with the installation position p21 of the rail insulating device 7k-1 as a boundary. In the grounded system, the rail-to-ground voltage is reduced to 0 starting point at the operating position p20 of VLD6i-1, while in the ungrounded system it maintains the state before VLD6i-1 was turned on.

Note that FIG. 8 shows an example in which an opening command is input to the nearest rail insulating device 7k-1 on the right side of the VLD 6i-1. If the rail insulators 7 are installed on both the left and right sides of the rail 4 of the VLD 6i-1 in the longitudinal direction, the open command is input to the nearest rail insulators 7 on both the left and right sides.

As described above, according to the present embodiment, in an electric railway equipped with a plurality of VLDs 6 and a plurality of rail insulating devices 7, the rail insulating device 7 closest to the VLD 6 that detects deviation of the rail-to-ground voltage from the allowable range is operated. . Therefore, it is possible to minimize the influence range of the variation of the rail-to-ground voltage at the operating position of the VLD 6 and suppress the rail-to-ground voltage far from the VLD 6 .

[Embodiment 3]
<Configuration of rail-to-ground voltage suppression system 3S according to Embodiment 3>
FIG. 9 is a configuration diagram of a rail-to-ground voltage suppression system 3S according to Embodiment 3 of the present invention. In comparison with the rail-to-ground voltage suppression system 2S of the second embodiment, the rail-to-ground voltage suppression system 3S rejects the received open command 8 and insulates the rail 4 when the rail isolation device 7 receives the lock command 701. The difference is that an open command 702 is output to the adjacent rail insulating device 7 without performing any operation.

When the rail insulating device 7 receives either the open command 8 from the VLD 6 or the open command 702 from the adjacent rail insulating device 7 when it has not received the lock command 701, the rail 4 acts as an insulator. On the other hand, when the rail isolator 7 receives the lock command 701 , it maintains the conduction state of the rail 4 regardless of the open commands 8 and 702 from the VLD 6 . In addition, when the rail insulating device 7 receives the lock command 701 and receives the open command 8 or 702, it outputs the open command 702 to the adjacent rail insulating device 7 on the opposite side of the receiving the open command 8 or 702. By doing so, the opening command is transferred to the nearest rail insulating device 7 .

<Configuration of Rail Insulating Device 7 According to Third Embodiment>
FIG. 10 is a configuration diagram of a rail insulating device 7 according to Embodiment 3 of the present invention. 10, the input/output to/from the rail insulating device 7 will be described using the rail insulating device 7k of FIG. 9 as an example.

When the rail insulating device 7k receives either the open command 8i from the VLD 6i located on the left side of the rail insulating device 7k shown in FIG. 9 or the open command 702k-1_k from the rail insulating device 7k-1, An open command 8L from the left side is generated by the OR circuit 801L. When the rail insulating device 7k receives either the open command 8i+1 from the VLD 6i+1 located on the right side shown in FIG. It is generated by a summing circuit 801R. The rail insulating device 7k generates the opening command 8' by the OR circuit 601 when at least one of the opening command 8L from the left side and the opening command 8R from the right side is generated.

The AND circuit 802 generates an open command 8'' based on the generated open command 8' when the lock command 701k is not received. The rail insulating device 7k opens the circuit breaker 303 in response to the opening command 8''. On the other hand, when the lock command 701k is received, the AND circuit 802 does not generate the open command 8'' and keeps the circuit breaker 303 closed.

Although the opening command 8L from the left side is generated, if the opening command 8'' is not generated and the circuit breaker 303 cannot be opened, the rail insulating device 7k moves to the adjacent rail insulating device 7k+1 in the right direction. is generated by the AND circuit 804R.

In addition, when the open command 8R from the right side is generated but the open command 8'' is not generated and the circuit breaker 303 cannot be opened, the rail insulating device 7k does not open the adjacent rail in the left direction. An open command 702k_k-1 for device 7k-1 is generated by AND circuit 804L.

As the lock command 701, it is conceivable to input a signal as shown in the table below depending on the purpose. An automatic lock function can be realized by using the current or railroad signal in the table below as the lock command 701 depending on the purpose.

For the purpose of "preventing large fluctuations in the power supply path" in the above table, for example, when the VLD 6 is turned on, if the "current of the breaker 303" is equal to or greater than the threshold, the circuit breaker 303 is kept closed. and generates a lock command 701 that releases this circuit breaker 303 when the "current of the circuit breaker 303" is less than the threshold. In response to this lock command 701, only the rail isolating device 7 closest to the VLD 6 whose current flowing through the circuit breaker 303 is below the threshold among the plurality of rail isolating devices 7 connected to the VLD 6 with the rail 4 grounded opens the circuit breaker 303. be released. Therefore, it is possible to suppress a change in the feeding current path when the circuit breaker is opened.

<Effect of Embodiment 3>
FIG. 11 is a diagram for explaining the action of Embodiment 3 of the present invention. FIG. 11 shows an example where only the rail isolator 7k-1 of the three rail isolators 7k-1, 7k, 7k+1 has received the lock command 701 (701k-1=1).

According to this embodiment, when the rail-to-ground voltage at the operating position p30 of the VLD 6i-1 deviates from the allowable range, the VLD 6i-1 is closed and the rail-to-ground voltage at the operating position p30 becomes zero. As the VLD 6i-1 is turned on, an open command 8i-1 is output to the rail insulating device 7k-1. Since the rail insulating device 7k-1 has received the lock command, it rejects the open command. Therefore, the rail 4 is maintained in a conducting state at the installation position p31 of the rail insulating device 7k-1. Also, the rail insulating device 7k-1 transfers the open command to the adjacent rail insulating device 7k.

On the other hand, since the rail insulating device 7k has not received the lock command, it insulates the rail 4 according to the received open command.

As a result, the rail 4 is divided into a grounded system and a non-grounded system with the installation position p32 of the rail insulating device 7k as a boundary. In the grounded system, the rail-to-ground voltage is reduced so that the operating position p30 of the VLD 6 becomes the 0 starting point, while in the non-grounded system the state before the VLD 6 is turned on is maintained.

As described above, according to the third embodiment, by insulating the rail 4 with the rail insulating device 7 closest to the VLD 6 among the unlocked rail insulating devices 7 as a boundary, It is possible to suppress an increase in the rail-to-ground voltage at .

[Embodiment 4]
<Configuration of rail-to-ground voltage suppression system 4S according to Embodiment 4>
FIG. 12 is a configuration diagram of a rail-to-ground voltage suppression system 4S according to Embodiment 4 of the present invention. The rail-to-ground voltage suppression system 4S is different from the rail-to-ground voltage suppression system 3S of the third embodiment in that when the rail insulating device 7 receives the reclosing command 1001, the circuit breaker 303 is switched from the open state to the closed state. is different.

<Configuration of Rail Insulating Device 7 According to Fourth Embodiment>
FIG. 13 is a configuration diagram of a rail insulating device 7 according to Embodiment 4 of the present invention. In FIG. 13, the input/output to/from the rail insulating device 7 will be explained using the rail insulating device 7k of FIG. 12 as an example. When the trigger circuit 1301 detects the rise of the reclosing command 1001k, the rail insulating device 7k generates a cancellation command 1311 for rejecting the opening command 8''. The reclosing command 1001k is input, for example, from an input device installed on site or at an operation control center.

The state of the cancel command 1311 is held as a cancel command 1311 ′ by a self-holding circuit formed by feedback of the cancel command 1311 ″ to the OR circuit 1302 . The cancel command 1311 ″ is canceled by the AND circuit 1304 when the trigger circuit 1303 detects the re-rising of the open command 8 ″.

The AND circuit 1305 generates the open command 8''' when the open command 8'' is generated but the cancel command 1311 is invalid. The circuit breaker 303 is opened by the opening command 8'''. On the other hand, the AND circuit 1305 does not generate the open command 8'' when the cancel command 1311 is valid even though the open command 8'' is generated. Therefore, the interrupted state of the circuit breaker 303 is maintained.

With the above configuration, in a situation where it is necessary to close the circuit breaker 303 prior to opening the VLD 6 (for example, in a situation where the risk of electric shock to a track maintenance worker due to a large potential difference between the rails of the insulated joint 301 needs to be eliminated early) , to enable manual reclosing of the circuit breaker.

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Also, as long as there is no contradiction, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is possible to add, delete, replace, integrate, or distribute a part of the configuration of each embodiment. Also, the configurations and processes shown in the embodiments can be appropriately distributed, integrated, or replaced based on processing efficiency or implementation efficiency.

1A: Vehicle, 2: Power supply, 3: Overhead line, 4: Rail, 5: Grounding, 6: VLD (short-circuit switch), 7: Rail insulator, 8: Open command, 301: Insulated joint, 302: Jumper wire, 303 : circuit breaker, 304: impedance bond, 701: lock command (lock command), 702: open command, 1001: reclose command

Claims (8)

A rail-to-ground voltage suppression system in an electric railway,
a first switch that short-circuits the rail to ground in the actuated position upon detecting that the rail-to-ground voltage in the actuated position has deviated from an allowable range;
a second switch for switching the rail, in which the insulating portion is inserted into the rail joint, between an insulating state in the insulating portion and a conducting state across the insulating portion;
A rail-to-ground voltage suppression system, wherein the second switch switches the rail to an isolated state when the first switch short-grounds the rail. Having a plurality of the second switches,
2. The rail of claim 1, wherein when the first switch shorts the rail to ground, the second switch relative to the first switch switches the rail to an isolated state at the installation position of the device. Ground voltage suppression system. 3. The method of claim 2, wherein the second switch relative to the first switch is the second switch closest to the first switch on both longitudinal sides of the rail. Rail-to-ground voltage suppression system. When the second switch receives the lock command, even if the first switch short-circuits and grounds the rail, the second switch does not switch the rail to an insulated state at the installation position of the device itself, but maintains the conductive state. 4. The rail-to-ground voltage suppression system according to claim 2 or 3, characterized by: The second switch transmits an opening command for switching the rail to an insulated state to the adjacent second switch when the first switch short-circuits and grounds the rail when receiving the locking command. ,
When the adjacent second switch receives the open command,
If the lock command is not received, the rail is switched to an insulated state at the installation position of the device,
2. When the lock command is received, the rail is not switched to the insulated state at the installation position of the self-device, and the open command is transferred to the adjacent second switch. 5. The rail-to-ground voltage suppression system according to 4. 6. The rail-to-ground voltage suppression system according to claim 5, wherein the second switch switches the rail to the conductive state at the installation position of the device when receiving a reclosing command. the second switch includes a third switch that switches the rail between a conductive state and an isolated state;
7. The rail-to-ground voltage suppression system according to claim 5, wherein the locking command for the second switch including the third switch is generated based on the current flowing through the third switch. . The rail-to-ground voltage suppression system according to claim 5 or 6, wherein a predetermined railroad signal is used as the locking command.

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