KR101906164B1 - Control circuit for selective drainage current - Google Patents

Abstract

The distribution control circuit according to the present invention comprises a limiting resistor connected between a rail and a submerged pipe, a first diode element connected in series between the limiting resistor and the submerged pipe, and a first diode element connected in parallel at both ends of the first diode element And generates a compensating current so that the current flowing through the limiting resistor maintains a predetermined value.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

Various embodiments of the present invention relate to a distribution control circuit that controls the flow of current between a railway track and an underground pipeline.

If the leakage current of the electric railway flows into the piping buried in the vicinity of the DC electric railway, the pipeline can be abruptly corroded as the incoming electric current flows out to the soil. In order to prevent corrosion of buried piping, a circulation system is used in which a railway rail and an underground pipeline are connected to each other and a leakage current flowing into a buried pipeline is returned to a railway rail.

However, in the vicinity of a substation for supplying electric power to a train, or in the vicinity of a railway station where braking of a train is performed, an excessive current flows through the buried pipe, resulting in overfilling of the buried pipe or melting of the bonding wire of the valve chamber. Therefore, a selective discharge system has been proposed to control the excess current flowing in the buried piping.

The distribution control circuit according to various embodiments of the present invention stably maintains the method potential of the buried pipe by controlling the current to be supplied to the railway rail constantly when the potential of the railway track is lower than the potential of the buried pipe.

The distribution control circuit according to the various embodiments of the present invention can minimize the power consumption that may occur when the system potential of the buried piping is kept constant while not in the selective distribution state.

The distribution control circuit according to an embodiment of the present invention includes a limiting resistor connected between a rail and an underground buried pipe, a first diode device connected in series between the limiting resistor and the buried underground pipe, And a forced discharging circuit connected in parallel at both ends of the element to generate a compensating current so that a current flowing in the limiting resistor maintains a predetermined value.

In one embodiment, the distribution control circuit includes a switching circuit connected in parallel at both ends of the limiting resistor to perform a switching operation, and a rail-to-pipe potential (corresponding to a voltage difference between the railway rail and the underground pipeline V _{R / P} ) according to the polarity of the switching signal.

In one embodiment, the predetermined value of the current flowing through the limiting resistor may be determined based on the maximum absolute value of the rail-to-pipe potential (V _{R / P} ).

In one embodiment, the controller may control the switching circuit to be on when a predetermined time has elapsed from a time point when the rail-to-pipe potential changes to an anode.

In one embodiment, the controller may control the switching circuit to be turned off when the rail-to-pipe potential changes to the cathode.

In one embodiment, the distribution control circuit further comprises a current sensing element connected between the limiting resistor and the rail, and the forced current generating circuit generates the compensation current based on the sensing current of the current sensing element .

In one embodiment, the forced feed circuit includes a voltage source providing a different voltage based on the sense current, and a second diode element coupled between the voltage source and the limiting resistor and the first diode element can do.

In one embodiment, the forced distribution circuit may include a current sensing element coupled between the voltage source and the second diode element.

In one embodiment, the limiting resistor may be provided in a separate resistor box.

According to the various embodiments disclosed in this document, the distribution control circuit keeps constant the method potential of the buried pipe by causing a constant value of the flow current to flow through the limiting resistor provided between the railway rail and the underground buried pipe. As a result, it is possible to prevent over-discharge of buried piping and stable current control is possible despite sudden change of rail-to-pipe potential.

According to the various embodiments disclosed in this document, the distribution control circuit allows a constant value of the supply current to flow through the limiting resistor, by controlling the path of the supply current flowing in the limiting resistor in accordance with the polarity of the rail- Thereby minimizing the power consumed by the components provided.

It will be apparent to those skilled in the art that various modifications, additions, and substitutions are possible, without departing from the spirit and scope of the appended claims, As shown in Fig.

FIG. 1 is a view for explaining the concept of selective distribution according to leakage current of a DC electric train. FIG.
FIGS. 2A and 2B are graphs showing the potential relationship between the rails, piping, and ground at the time of selective distribution and the magnitude of the discharged current.
3 is a view showing a distribution control circuit according to an embodiment of the present invention.
FIG. 4 is a diagram illustrating a selected discharge current and a forced discharge current according to an embodiment of the present invention. FIG.
5A and 5B are views showing a distribution control circuit according to an embodiment of the present invention.
FIG. 6 is a diagram for illustrating a control effect of a discharge current through a discharge control circuit according to embodiments of the present invention.
FIG. 7 is a diagram for illustrating a control effect of a discharge current through a discharge control circuit according to an embodiment of the present invention. FIG.
8 is a circuit diagram showing a distribution control circuit according to an embodiment of the present invention.

Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In this document, the same reference numerals are used for the same constituent elements in the drawings, and redundant explanations for the same constituent elements are omitted.

For the various embodiments of the invention disclosed herein, specific structural and functional descriptions are set forth for the purpose of describing an embodiment of the invention only, and various embodiments of the invention may be practiced in various forms And should not be construed as limited to the embodiments described herein.

Expressions such as " first, "second," first, "or" second, " as used in various embodiments, Not limited. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be named as the first component.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the other embodiments. The singular expressions may include plural expressions unless the context clearly dictates otherwise.

All terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art. Commonly used predefined terms may be interpreted to have the same or similar meaning as the contextual meanings of the related art and are not to be construed as ideal or overly formal in meaning unless expressly defined in this document . In some cases, the terms defined in this document can not be construed to exclude embodiments of the present invention.

FIG. 1 is a view for explaining the concept of selective distribution according to leakage current of a DC electric train. FIG.

Referring to Fig. 1, there is a duct P embedded in the lower part of the vicinity of the DC rail R and the railway rail R.

There are two electric trains EV1 and EV2 on the train rail (R). One electric train (EV2) is in operation and the other electric train (EV1) is in braking. The first train EV1 is braked by a regenerative braking system. Regenerative braking system refers to the system that converts the electric motor of the electric motor to the generator when braking.

The first electric train EV1 which is being braked transfers electric current to the second electric train EV2 which is in operation via the electric wire connected to the upper part of the electric train. Therefore, a current enough to compensate the current thus transmitted is supplied from the second electric train EV2 to the electric rail (R) to the first train (EV1). At this time, the first electric train EV1 under braking is in a state in which the current of the electric railway R is drawn, and the electric potential of the electric railway R instantaneously becomes the negative.

However, since leakage current generated from the second train EV2 in operation flows into the buried pipe P and current flowing through the buried pipe P flows back into the soil, the pipe P is corroded And a diode element D and a variable resistor VR are connected between the buried pipe P and the train rail R. [ The current component of the buried pipe P is transmitted to the railway rail R through the diode element D and the variable resistor VR so as to minimize the corrosion of the buried pipe P. [ Railway station with rails - if the pipe potential (V _{R / P)} that has a positive value was ilkeol that baeryu current the current delivered to the buried pipe train rail in (P) (R), the rail-pipe potential (V _{R / P} ) has a negative value and the rush current increases sharply.

The train rail R becomes a state in which the current of the buried pipe P is also sucked in an instant and the buried pipe P is in a state of sucking the stray current flowing out of the railway R again . There is a problem that the buried pipe P is liable to be overdosed if a large amount of wake current flows around the buried pipe P, so it is necessary to keep the current at the time of the selective discharge constant.

For example, the buried piping (P) may include a gas conduit, a water pipe, and a communication wire protective pipe.

FIGS. 2A and 2B are graphs showing the potential relationship of the railway, the buried pipe, and the soil and the magnitude of the discharged current at the time of the selective distribution.

FIG. 2A is a graph showing a relationship between a voltage difference between a railway track and a buried pipe and a discharge current, and FIG. 2B is a graph showing a relationship between a voltage difference between the buried pipe and the ground and a discharge current.

Referring to FIG. 2A, it can be seen that the discharged current is steadily increased when the rail-to-pipe potential (V _{R / P} ) is negative although the discharged current is always maintained at a constant value.

Similarly, referring to FIG. 2B, if the potential (V _{P / S} ) between the buried pipe and the ground suddenly decreases, current components flow into the buried pipe P and the magnitude of the discharged current rapidly increases.

Baeryu according to the present invention in order to avoid this, the control circuit train rail (R) and the buried pipe (P) installed, and the rails for limiting resistance between - baeryu passing through the limiting resistor regardless of the pipe potential (V _{R / P)} And a forced distribution circuit for keeping the current constant.

3 is a view showing a distribution control circuit according to an embodiment of the present invention.

3, the distribution control circuit may include a limiting resistor rl and a forced distribution circuit (FDC) connected in series between the railway track R and the submerged pipe P.

The potential between the railway rail R and the buried pipe P corresponds to the rail-to-pipe potential V _{R / P} and the potential corresponds to the condition of the railway rail R and the buried pipe P You can have different values depending on it. Depending on the embodiment, the rail ground resistance r0 and the piping ground resistance r1 component may be connected to the rail-to-pipe potential _{VR / P.}

The flow current Id corresponds to the current supplied from the buried pipe P to the train rail R and may correspond to the current flowing in the limiting resistor rl. The forced distribution circuit FDC is connected in parallel to both ends of the first diode element D1 to generate a forced discharge current If so that the current flowing through the limiting resistor rl maintains a predetermined value. The forced discharge current If allows the selected discharge current Is to maintain a predetermined value, which may also be referred to as a compensation current. The forced-discharge circuit FDC can generate the forced-discharge current If of different sizes based on the magnitude of the selected discharge current Is.

If the limiting resistance rl has a constant value, the selected current flow Is has a different value depending on the magnitude of the rail-to-pipe potential V _{R / P.} Therefore, the magnitude of the selected flow current Is may be varied depending on the rail-to-pipe potential (V _{R / P} ). A change in the magnitude of the selected flow current Is can have a secondary effect on the potential of the buried pipe P so that the forced discharge current If is generated through the forced discharge circuit FDC and the selected discharge current Is). The magnitude of the discharged current Id finally flowing through the limiting resistor rl is kept constant as the forced discharging current If is compensated for the selected discharging current Is.

Depending on the embodiment, the force baeryu circuit (FDC) may include a second diode element (D2) and a forced supply (V _f). Forcing power (V _f) may correspond to the current source to provide a different voltage depending on the size of the selected baeryu current (Is) or size baeryu current (Id) of the.

The forced discharge current If is combined with the selected discharge current Is to constitute a discharge current Id which detects the discharge current Id and if the magnitude of the discharge current Id is smaller than a preset value forcing power (V _f) the amount of force baeryu current to increase the value of (If), or select baeryu current (is) selected baeryu current (is) to detect the size of the controls so as to increase the magnitude of the voltage that is provided And calculates the magnitude of the forced discharge current If to maintain the discharge current Id at a predetermined value and controls the voltage magnitude of the forced power source V _f to be suitable for the magnitude of the forced discharge current If .

FIG. 4 is a diagram illustrating a selected discharge current and a forced discharge current according to an embodiment of the present invention. FIG.

Fig. 4 exemplifies a case where the flow current Id is set to a constant value of 9.4A. When the rail-to-pipe potential (V _{R / P} ) is -40V, the selected flow current Is may be 7.5A. The forced discharge circuit FDC can generate a forced discharge current If of 1.9 A to flow to the limiting resistor rl in order to maintain the discharge current Id at a constant value.

As can be seen from FIG. 4, it can be seen that the selected flow current Is increases linearly and the forced flow current If decreases linearly according to the rail-to-pipe potential (V _{R / P} ). With this operation, the current Id flowing in the limiting resistor rl can always be maintained at a constant value. The magnitude of the flow current Id flowing in the limiting resistor rl can be set to the largest value based on the maximum absolute value of the rail-to-pipe potential V _{R / P.}

For example, in FIG. 4, if the maximum absolute value of the rail-to-pipe potential (V _{R / P} ) can be 50 V and the limiting resistance rl is 5 Q, And may be set to 9.4 A, depending on the embodiment.

However, the forced discharge current If can be generated even when the selected discharge current Is does not occur at all, that is, the rail-to-pipe potential (V _{R / P} ) has a positive value. When the selected rail current Is is hardly generated because the rail-to-pipe potential V _{R / P} has a positive value, the magnitude of the forced discharge current If becomes large. The power consumption can be increased if it flows through the limiting resistor rl.

For example, as we have seen, let's assume that the selective current Is does not occur at all. For example, when the limiting resistance rl is 5 OMEGA, the forced discharge current If itself has a value close to 10 A to fill a predetermined value of the discharged current Id. When all of the forced discharge current If flows through the limiting resistor rl, it consumes 500 Wh of power per hour. As described above, when no selective current Is is generated at all, significant power consumption may occur.

5A and 5B are views showing a distribution control circuit according to an embodiment of the present invention.

The distribution control circuit shown in Figs. 5A and 5B may further include a switching circuit MC3 as compared with the distribution control circuit shown in Fig. The switching circuit MC3 can be connected in parallel to both ends of the limiting resistor rl to perform the switching operation based on the polarity of the rail-to-pipe potential (VR _{/ P} ).

When Figure 5a is selected baeryu, that is rail-pipe potential will illustrating an operation in the case where (V _{R / P)} has a negative value, Figure 5b rail sanitary potential (V _{R / P)} that has a positive value of In FIG.

5A, when the rail-to-pipe potential (V _{R / P} ) has a negative value, the selected flow current Is flows to the limiting resistor rl and the magnitude of the current flowing in the limiting resistor rl is The forced discharge current If is added through the limiting resistor rl so as to be the same as the magnitude of the predetermined discharged current Id. At this time, the switching circuit MC3 remains off.

When the rail-to-pipe potential (V _{R / P} ) has a positive value, the first diode element D 1 limits the selective current Is through the rail-to-pipe potential (V _{R / P} ). Therefore, the selection current Is does not flow through the limiting resistor rl and a considerably large forced current Ie generated through the forced discharging circuit FDC is provided to the limiting resistor rl.

5B, the switching circuit MC3 is turned on via the control signal provided through the control section (see FIG. 8), and the forced current Io is supplied to the limiting resistor rl, But flows through the path formed by the switching circuit MC3. Accordingly, the forced discharge current If does not flow through the limiting resistor rl, thereby reducing power consumption.

FIG. 6 is a diagram for illustrating a control effect of a discharge current through a discharge control circuit according to embodiments of the present invention.

6 is the same as FIG. 2A, and shows that the flow current rapidly increases when the rail-to-pipe potential (V _{R / P} ) has a negative value. The right side view of FIG. 6 shows the discharge current according to the discharge control circuit according to an embodiment of the present invention. In the case where the rail-pipe potential (V _{R / P} ) has a positive value and a negative value It can be confirmed that the value of the discharged current is kept constant regardless of the value of the discharge current.

FIG. 7 is a diagram for illustrating a control effect of a discharge current through a discharge control circuit according to an embodiment of the present invention. FIG.

7 is the same as FIG. 2B. It can be seen that the value of the discharged current also increases when the tube potential (V _{P / S} ) is abruptly lowered. The right side of FIG. 7 shows the relationship between the drain current and the tube potential (V _{P / S} ) according to the distribution control circuit according to the embodiment of the present invention. The relationship between the distribution potential (V _{P / S} ) It can be confirmed that the discharge current is maintained at a constant value.

8 is a circuit diagram showing a distribution control circuit according to an embodiment of the present invention.

Compared with the distribution control circuit described with reference to Figs. 5A and 5B, the distribution control circuit shown in Fig. 8 may further include a control unit CTRU. Therefore, the same reference numerals are used for the same components as those described above. The same components perform substantially the same operations, so a detailed description thereof will be omitted.

The control unit CTRU receives the values of the first node ND1 in the vicinity of the train rail R and the second node ND2 in the vicinity of the buried pipe P. [ The controller CTRU can determine the polarity of the rail-to-pipe potential V _{R / P} by measuring the potential between the first node ND1 and the second node ND2.

The control unit CTRU controls the operation of the switching circuit MC3 in accordance with the polarity of the rail-to-pipe potential V _{R / P.} The controller CTRU turns on the switching circuit MC3 when the rail-to-pipe potential V _{R / P} is an anode so that the forced discharge current If becomes an electrical So that the forced regenerative current If does not flow through the limiting resistor rl.

According to the embodiment, the control unit CTRU may have a timer inside (not shown). The control unit CTRU operates the timer at a time point when the potential between the first node ND1 and the second node ND2 changes from negative to positive and the switching circuit MC3 is turned on after a predetermined time has elapsed State can be controlled. This is to prevent the chattering phenomenon while the polarity of the rail-to-pipe potential (V _{R / P} ) changes, that is, the rail-to-pipe potential (V _{R / P} ) Conversely, the control unit CTRU controls the switching circuit MC3 to be in an OFF state after a predetermined time has elapsed by operating the timer at the time when the rail-to-pipe potential V _{R / P} changes from positive to negative . According to an embodiment, the control unit CTRU may comprise a meter relay.

The distribution control circuit according to an embodiment of the present invention includes a current sensing element S1 connected between the limiting resistor rl and the railway rail R, that is, between the limiting resistor rl and the first node ND1 can do. The current sensing device S1 may include a shunt resistor capable of sensing the magnitude of the current Id. Control (CTRU) controls the size of the forced power supply (V _f) to receive a value detected by the current sensing element (S1), and the force power source (V _f) is forced baeryu current of different sizes according to the control value (If ) Through the second diode element D2 as the limiting resistor r1.

The current value detected by the current sensing element (S1) is fed back to the control unit (CTRU), forcing the power (V _f) is adjusted in size As thus maintained at a value the magnitude of baeryu current (Id) of a predetermined in by the feedback value .

Further, FIG. 8, the force baeryu circuit (FDC) may further include a current sensing device (S2) connected between a power force (V _f) and a second diode element (D2). The current sensing element S2 can sense the magnitude of the forced discharge current If. The current sensing element S2 may comprise a shunt resistor.

Depending on the embodiment, a considerable amount of current may flow through the limiting resistor rl, which may cause a lot of heat, so that other circuits near the limiting resistor rl may be damaged. Thus, the limiting resistor rl may be located in a separate resistor box.

According to the embodiment, the distribution control circuit according to the embodiment of the present invention can transmit the measured values of the discharged current Id and the forced discharge current If with the communication means to an external server. It is also possible to transmit not only the current value but also the value of the rail-to-pipe potential V _{R / P} which observes the potential difference between the first node ND 1 and the second node ND 2 to the server.

A system may be provided which integrally manages the buried piping by integrally managing the measured values in the external server.

As described above, the distribution control circuit according to the embodiments of the present invention generates the forced discharge current If for the selected discharge current Is having a different value according to the rail-to-pipe potential (V _{R / P} ) (Id). Accordingly, the magnitude of the flow current Id can be maintained at a predetermined value despite fluctuations of the rail-to-pipe potential (V _{R / P} ). In addition, the distribution control circuit according to the embodiments of the present invention is designed so that the forced discharge current If does not exceed the limiting resistance rl in order to prevent power consumption that may occur due to the flow of the limiting resistor rl, And a switching circuit MC3 connected in parallel with the switching circuit MC3 to control the forced flow current If to flow to an alternative path if not the selected flow.

A system according to various embodiments may include at least one or more of the elements described above, some of which may be omitted, or may further include other additional elements. And the embodiments disclosed in this document are presented for the purpose of explanation and understanding of the disclosed technical contents, and do not limit the scope of the present invention. Accordingly, the scope of this document should be interpreted to include all modifications based on the technical idea of the present invention or various other embodiments.

R: Train rail
P: buried piping
rl: Limit resistance
FDC: forced distribution circuit
MC3: Switching circuit
CTRU:

Claims (9)

Limiting resistors connected between rail and underground piping;
A first diode element connected in series between the limiting resistor and the underground buried pipe; And
A forced excitation circuit connected in parallel to both ends of the first diode element to generate a compensating current so that a current flowing through the limiting resistance maintains a predetermined value;
A switching circuit connected in parallel to both ends of the limiting resistor to perform a switching operation; And
And a control section for controlling the switching operation based on a polarity of a rail-pipe potential (V _{R / P} ) corresponding to a voltage difference between the railway rail and the underground pipeline. delete The method according to claim 1,
And the predetermined value of the current flowing through the limiting resistor is determined based on a maximum absolute value of the rail-to-pipe potential (V _{R / P} ). The method of claim 3,
Wherein,
And controls the switching circuit to be on when a predetermined time has elapsed from a time point when the rail-to-pipe potential changes to an anode. The method of claim 3,
Wherein,
And the switching circuit is turned off at a time point when the rail-to-pipe potential changes to the cathode. The method of claim 4,
Further comprising a current sensing element connected between the limiting resistor and the railway rail,
Wherein the forced current circuit generates the compensation current based on the sense current of the current sensing device. The method of claim 6,
Wherein the forced-
A voltage source for providing a different voltage based on the sense current; And
And a second diode element connected between the voltage source and the limiting resistor and the first diode element. The method of claim 7,
Wherein the forced-
And a current sensing element connected between the voltage source and the second diode element. The method according to claim 1,
Wherein the limiting resistor is provided in a separate resistor box.

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