JPS6047801B2 - Track short circuit detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Various types of track currents are passed through a railway track (hereinafter referred to as a "rail") within a limited section, that is, a so-called section.

When a train is on the track within this section, the train's wheelsets (hereinafter referred to as "cars") short-circuit the rails, and the state of the track current changes significantly.
A method that detects the presence of a train within a section by capturing this phenomenon is widely used in railway signal control and other applications. The present invention relates to a method for detecting a situation where a vehicle short-circuits the current flowing through the rail.

Among the methods for detecting train presence in a section, there are various methods that use short-circuit phenomena between rails and cars, but the most commonly used method is to apply track current from the beginning of the section to a pair of rails. A circuit is configured to receive the track current at the final end of the section, and when there is no train in this section, the track current is received at the final end, but when a train is on the track, the track current is received by the train car. This method detects the presence of a train by detecting the inability to receive track current due to short-circuiting of the rails. According to such a system, a rail short-circuit is reliably performed when the rail is crimped by multiple cars with heavy wheel loads.Moreover, if the track current cannot be received at the end of the section due to breakage of the rail, etc. It has the advantage of making it appear as if a train was on the line within that section.
This method has long been used as a means of detecting train presence.

However, even though the rails are constantly crimped by the many cars of such a heavy train, the electrical contact between the rails and the cars is still critical. Although this is not necessarily the case and is extremely rare, a so-called short-circuit failure phenomenon is occurring.

If a short-circuit failure occurs in all the cars of trains on the track in a section, the signal circuit in that section will be in the same state as if there were no trains on the track, and train control and train signalling. If such a phenomenon occurs in a section that performs control, there is a concern that a serious situation will occur in which vehicles will interfere with each other. There is a concern that a dangerous accident could occur due to a door or no warning, and furthermore, in sections where switches are protected from switching midway through, a dangerous situation may occur if the switch switches while the train is passing through it. The reason why track short circuit failures, which are extremely dangerous, occur is because some kind of non-conductor, such as oil, sand, or dust, temporarily intervenes between the rail and the car. Or, the wheel load of the car may temporarily fluctuate greatly due to vibration, etc., causing a so-called wheel load drop phenomenon, resulting in poor contact between the rail and the car. Although various causes have been considered, such as whether this is the case, it is important to understand the specific phenomenon. It is extremely difficult to determine the cause of this phenomenon, and even though various studies and surveys are currently being conducted from various fields, the cause has not been clarified.

For this reason, recent efforts have been made to conduct basic research in which the contact resistance between the car and the rotating body is measured by bringing the car into contact with a rotating body similar to a rail while rotating it on a quantitative test stand, and by testing short circuits on the main line. Although we have set up a dedicated section to investigate the situation and are conducting tests to investigate the short-circuit condition of the entire train passing through that section, it is difficult to obtain concrete results, and the cause is therefore unknown. Needless to say, no measures have been established to prevent short circuit failures. All track currents used for signal control, etc. are powered by AC power.

If the track current sent out at the beginning of the section is reliably short-circuited by the presence of a train on the track, then the track current will generally be the same as that of the first train near the beginning of the section. Since the short circuit is made at the car (generally the first car in the train), the track current in that section will not flow to the rails after this car. However, even if there is a track short-circuit defect caused by the first car, at the very least, it is impossible for track current to flow to the rear of the last car in the train (toward the end of the section). . Therefore, in order to investigate the track short circuit situation of the train one by one, a known power receiver for detecting track current is installed on the train car, and its position is usually close to the vehicle control device (
Rather than installing it at the front of the train like power receivers installed to detect track current such as ATC),
By installing at least one power receiver behind the front car and investigating the status of the track current detected by this power receiver, it is possible to continuously know the status of track short circuits on the train. Moreover, if such a method is adopted, it will be possible to very easily understand the relationship between other factors of the train, such as vibration conditions, brake operation conditions, etc., and the short-circuit failure.

A feature of the present invention is that the beginning of the train section (
At least one power receiver for detecting track current is installed on the car behind the first (usually the frontmost) car on the side (track current sending point), and this receiver is used to detect track short circuit conditions. Detection/
It's about investigating. Next, in order to explain one embodiment of the present invention, the situation of conventional train presence detection using track current will be described with reference to FIG.

In Fig. 1, a track current is sent from a power source Sa to a pair of rails RL from a point a near the starting end, which is one boundary of a signal section where a certain track current flows, via a known track transformer (not shown), etc. The track current is received by the impedance bond EB installed at the end of the section.

When a train is not on the track within this section, the track current transmitted to the impedance bond EB operates a relay, etc. that detects a known track current (not shown) connected to the impedance bond EB, and when a train is on the track within the section. Detects that it is not done.

Furthermore, as shown in the figure, when a train C is on the track, the rail RL is short-circuited by the train's front W and rear car W, so the impedance bond EB detects the track current. Therefore, it is possible to detect that a train is on the line within the section. The above-mentioned method is widely used in signal control, etc., as a means of detecting the presence of trains within a section. The feature of the present invention is to install a known power receiver for detecting track current at least at the rear of the front car W of the train in order to detect such a short-circuit situation between the rail and the car due to the track current. In addition, if necessary, a power receiver of the same structure is also provided in front of the front car W of the train.

Next, one embodiment of the present invention will be described based on the same figure.
In the figure, there is a rail RL in front of the front car Wf of train C.
A known track current detection power receiver R is provided to detect the track current flowing in the track current, and a power receiver Rb having the same structure is further provided.
is the front car W, and the rear car Wl is separated from the car by a distance of L.
, is installed in front of. These two power receivers are for detecting the track current flowing in the rail RL, and have a known structure suitable for the type of track current so that the level of this track current can be detected, and further, It is assumed that the installation position in the train C and the relative position with respect to the rail RL are also appropriately set so that it is easy to detect the optimum track current level according to the type of track current. The track current sent from the power source Sa is that when a train is in the section as shown in the figure, the rail RL is short-circuited by the train's cars, so the current value short-circuited by the cars in this case is equal to that at the front of the train. It can be detected by the power receiver R of .

(In addition to this, the current detected by power receiver R also accurately includes the track leakage current in the section behind power receiver R, but the track leakage current behind train C is compared to the short circuit current caused by cars. However, if it is not possible to short-circuit the complete rail RL with the preceding car W, then the following car Wb, etc. It will be short-circuited. and,
In this case, the power receiver R installed behind the front car W,
Since the track current can also be detected by B, such a situation can be immediately detected on the train. Let us explain the flow of orbital current in such a case based on FIG. 2.

FIG. 2 is an equivalent circuit diagram showing the track current situation in FIG. 1. Orbital current electricity? Connection point a between a and rail RL
The track current sent from the train C to the rail RL is short-circuited near the front of the train C by the short-circuit impedance Z1 between the front car W and the rail and the other short-circuit impedance Z2, and the short-circuit due to the short-circuit impedance Z1. The current is i1, and the short circuit current due to short circuit impedance Z2 is I.
2. If the sum of both short circuit currents is 11+I2=IO, then the short circuit current is 1. can be detected by the power receiver R, and since the short circuit current 12 can be detected by the power receiver R5, the current 11 short-circuited by the preceding vehicle W,
can be determined from i1=IO-12, and from this it is possible to know the specific short-circuit current situation and short-circuit failure situation of the preceding vehicle W. Furthermore, using other means,
By determining the potential difference between the rails RL in the vicinity of the train C, the short-circuit impedance of the preceding car W can be immediately determined.

Next, a specific embodiment of detecting the short circuit current of the front vehicle W will be described based on the block of FIG. 3.

In FIG. 3, the track current J detected by the power receiver R installed in front of the front vehicle W. information is transmitted to a receiver RV including a known detection, rectification and amplification mechanism,
This results in an orbital current value of 1. Conversion is detected. Similarly, the information about the track current J2 detected by the power receiver R installed at the rear of the front car W is converted by the receiver ')R'' of the same mechanism, and is converted into the track current 12. In this way, the two detected orbital current values are output to a comparator CP that has a built-in subtraction mechanism, and the comparison!!SiC.P uses a built-in subtraction mechanism to track current value 1.

By subtracting the similarly input track current value 12 from the comparator CP, it is possible to determine the track current value 11 that flows due to being short-circuited by the preceding vehicle W. As described above, in this embodiment, the track short circuit situation of the preceding car can be continuously detected on the train, and other train conditions that are considered to be the cause of the short circuit failure can be detected. For example, it is possible to very easily understand the relationship between brake operating conditions, speed, train wheel load fluctuations, etc. and track short circuits.

In this example, we have described the method of detecting the track short circuit situation for only the preceding vehicle, but if the vehicles to be detected are both vehicle W and vehicle W, the power receiver R, W
, and if necessary, it can be installed behind Wf.
It may also be placed after both Wb and Wb, and furthermore, the number of axles of the vehicle for detecting short-circuit failures is not limited to this embodiment.

In addition, we do not wish to specifically determine the current value flowing through the car (current value 11 in this example) regarding the short-circuit situation of the car that should be detected as in this example, but simply to determine whether or not there is a track short-circuit defect. If it is sufficient to detect the power, the power receiver R installed in front of the front car W of the train is not necessary, and it is sufficient to simply install the power receiver R behind the front car.
Furthermore, the current value detected by the power receiver R is 1 due to reasons such as the fact that the leakage current of the entire track is very small. When is almost constant no matter where the train is in the section, there is no need to install a power receiver R, so in this case as well, the detection of track short circuit conditions is carried out only by the power receiver R. can do. When track short-circuit conditions are investigated using this method, even if the track short-circuit condition is not defective, the power receiver installed at the rear of the car in front may detect track current, which may actually When conducting an investigation, etc., when such a situation occurs, this situation. It is desirable to take precautions to avoid mistakenly identifying this as a short-circuit defect.

Next, let's discuss an example of this. FIG. 4 is a side view of FIG. 1 with only the essential parts necessary for explaining the situation described above removed.

In the figure. -, and if the distance between the boundary in the signal section and the sending point a of the track current is b, then when there is no track short circuit fault in the vehicle Wf, the power receiver R detects the track current in the state shown in the figure. There's nothing to do. However, from the point when the train C moves in the direction shown and the car W, passes point a, the track current begins to flow through a circuit formed by the cars W and W6, starting from point a, and the car Wf The track current flows through a circuit that is short-circuited only by the vehicle Wb when the vehicle Wb advances outside the boundary of the section, and this state continues until the power receiver Rb passes the point a. Therefore, in such a case, a track short circuit will be detected on the vehicle even though it is not a defect. Specifically, the power receiver Rb detected a strong track current, and its duration approximately matched the length of time required for the train to travel a distance approximately equal to the illustrated distance L at the current speed of the train. At that time, it was nothing other than passing through such a section boundary, so I assumed it to be so on the car,
It is necessary to deny that this is caused by an inherent track short circuit defect.

Next, an embodiment of a method for detecting a track current detected only at the boundary of a section will be described based on the block diagram shown in FIG. 5. In this embodiment, it is assumed that the distance b between the point a and the section boundary in FIG. 4 is extremely short. In the figure, receiver RV'' receives information that it has received a signal current from power receiver Rb, and detects the received signal current using built-in detection, amplification, and rectification circuits (not shown), and In operation, information indicating that a track current has been detected is output to a counter CT including a known integrator and a signal end detector TR including a trigger generation circuit.

A speed generator SG consisting of a known pulse-type tachometer and directly connected to one of the wheel axles of the train C to capture train speed information.
outputs a pulse to the counter CT every time the train C travels a predetermined minute distance. Upon receiving the information that the signal current has been detected from the receiver RV'', the counter CT sets an internal counter to C using a known method and starts counting pulses output from the speed generator SG from that point on. , the total value counted is the distance L
It starts operating when it counts pulses equal to when the train has run, and outputs this fact as a trigger signal to a detector AND including a well-known AND logic circuit. On the other hand, the signal end detector TR starts operating when the information output from the receiver RV'' is interrupted, that is, when the power receiver Rb no longer detects the signal current, and activates the built-in trigger generation circuit. A trigger signal is output to the detector AND by driving it in a known manner.Thus, the detector AND
The signal is activated only when the signals from the counter CT and the signal end detector TR are input at the same time, that is, when the time when the power receiver Rb detects the signal current matches the time required for the train C to travel the distance L. It considers the section boundary to be on the vehicle and detects that fact. In addition, in this example,
Although there is no mention of the type of signal current that the receiver R'' detects, there are cases where the status of the signal current that the receiver RV'' should detect changes while the receiver RV'' is in the receiving state. As shown in the figure, if connection point a does not coincide with the section boundary and the difference is large, the rising state of the signal level detected by the receiver may become unstable. It is necessary to thoroughly investigate the position of the signal, etc., and to appropriately determine the rise detection level when the signal is detected.In addition, in some cases, when verifying the length of the reception state, it is necessary to determine the reception length that should be the standard. Needless to say, it is necessary to make some corrections and tolerances, etc., as necessary. By using the detected section boundary information using this method, it is possible to eliminate the so-called erroneous track short circuit fault detection information that occurs when passing through a section boundary, so it is possible to eliminate the phenomenon of track short circuit faults. This allows for a more accurate understanding.

Then, for example, when a track short-circuit fault is detected by the power receiver Rb,
When trying to detect, if the power receiver R detects the track current for longer than the time required to travel the length L mentioned above at the current speed of the train, it indicates that the track short circuit situation of the car in front of it is not good. It can also be determined immediately.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram showing one embodiment of the present invention, Fig. 2 is an equivalent circuit diagram of a track circuit, Fig. 3 is a block diagram showing a device for determining the track short-circuit current value of an axle, and Fig. 4 1 is a side view showing a main part of the schematic explanatory diagram of FIG. 1, and FIG. 5 is a block diagram illustrating a method of detecting a section boundary. C...Train, RL...Rail, W,...
...Front car, W5...Rear car, R, R,
......Power receiver, R■, R■''...Receiver, Sa...Power source for track current.

Claims (1)

[Scope of Claims] 1. When detecting a short-circuit situation between a wheel set and the track where track current should be short-circuited, a power receiver installed on the vehicle to detect the track current is set at the point where the track current is sent to the rail. A track short circuit detection method, characterized in that a wheel set is installed so that a wheel set is interposed therebetween, and a track short circuit situation of the wheel set is detected from a track current detection state of the power receiver. 2. When detecting a short-circuit situation between the wheel set and the track where the track current should be short-circuited, the power receiver installed on the train to detect the track current should be connected to the point where the track current is sent to the rail, and the wheel set is By placing the power receivers at two locations, one on the vehicle with no intervening power receivers and the other on the vehicle with the wheel set interposed between them, and comparing the track current detection status of these two power receivers, it is possible to detect short-circuits between the wheel set and the track that exist between these two power receivers. A track short circuit detection method characterized by detecting the situation. 3. When detecting a short-circuit situation between a wheel set and the track where the signal current flowing on the track should be short-circuited, a power receiver installed on the train to detect the signal current flowing on the track should be installed on a car behind the frontmost wheel set of the train. The time required for the continuous detection of the signal current of the power receiver on the train to travel a distance equal to the length between the power receiver and the wheel axle immediately in front of it at the train's current speed. A method for detecting a track short circuit, comprising: detecting that the track short circuit condition of the wheel set in front of the power receiver is not good based on the fact that the time does not match.