JP6543587B2 - High voltage earthing relay for DC railway substation - Google Patents

Description

  The present invention relates to a high voltage grounding relay for a DC power iron substation, and in detail, a primary side electrical path (AC side) or a secondary side electrical path of a rectifier between a rectifier transformer and a rectifier of a DC power iron substation Operates when a ground fault occurs on the DC side) and determines whether the ground fault location is on the primary side (AC side) or secondary side (DC side) of the rectifier. The present invention relates to a high voltage ground relay for a DC railway substation having the same.

  Since the railway has been electrified in the past and rectifiers have been used, if a ground fault occurs in the DC bus at the DC railway substation, the large current in the ground will cause the substation equipment to burn out. A failure occurs. Therefore, the present applicant has keenly researched and detected the voltage between the grounding mat of the substation and the return line as shown in the following patent document (Japanese Patent Laid-Open No. 2010-42784), and power failure of the substation as soon as possible. In addition, we have invented and put into practical use DC high-voltage grounding relays to reduce damage to substation facilities and to protect substations.

  FIG. 12 is a diagram showing the configuration of a conventional direct current high voltage grounding relay. The DC high-voltage grounding relay 90 shown in FIG. 12 is installed between the grounding mat 91 of the substation and the return wire 92, and has a potential difference measuring unit 93 for measuring the potential difference between them. When a voltage is detected, a shutoff signal is sent to the AC circuit breaker 95A and the DC high speed circuit breaker 95 to shut off the power supply to the DC bus 94.

  FIG. 13 is a diagram showing a harmonic component of the current flowing through the ground line 98 to which the shield layer of the connection line between the rectifier transformer 96 and the rectifier 97 is connected in the normal state. In a general three-phase alternating current, in the normal state where no failure occurs, almost no current flows through the ground wire 98 if the three-phase collective grounding is used, but the diode of the return wire 92 and the rectifier 97 Since it is a special grounding system electrically connected to the true earth via it, the ground potential becomes a distorted waveform of positive / negative asymmetry. For this reason, even in the sound state, the sixth current caused by the fundamental wave current, the fifth harmonic current, the seventh harmonic current, and the secondary side rectification ripple due to the primary side of the rectifier 97 as shown in FIG. Various currents flow such as harmonic currents that are integral multiples of second harmonic currents. In addition, since the substation equipment and the support hardware are affected by the induction from the nearby electric path or the like, the current due to this also flows to the ground line. Further, 98R is an insulation resistance between the connection line 96A and the shielding layer 96B, 98R 'is a ground resistance, and 99 is a true ground.

  The DC high voltage ground relay 90 of the above configuration is disposed between the ground mat 91 of the substation and the return wire 92, and a potential difference measurement unit 93 for detecting the voltage is provided to prevent a ground fault of the DC bus 94 within the substation. To detect. That is, when a ground fault occurs in the DC bus 94, the ground mat 91 becomes positive (+) potential with respect to the return wire 92, so that the potential difference measurement unit 93 detects this and the AC breaker 95A cuts off the signal Output The AC breaker 95A can cut off the power supply promptly by cutting off the power supply based on the shutoff signal, thereby protecting the substation equipment and the like.

Unexamined-Japanese-Patent No. 2010-42784

  However, the conventional DC high voltage earthing relay 90 is not only a ground fault on the secondary side electric path (DC side) of the rectifier 97 of the DC power iron substation, but also the primary side between the rectifier transformer 96 and the rectifier 97. There is a characteristic that the circuit also operates due to a ground fault on the electric path (AC side), and there is a problem that these can not be determined.

  As the background, since DC transformer substations often have rectifier transformers 96 and rectifiers 97 placed close to each other due to the arrangement of substation equipment, they are connected by bare conductors such as bus bars or aluminum strands. There were many cases, but in recent years there has been a situation where the connection with bare conductors is reduced for safety reasons, and the connection with cables with shielding layers etc. has started. For this reason, rainwater etc. may intrude by degradation of the terminal processing of a cable etc., a cable may cause insulation degradation, and it may lead to a ground fault by this. In addition, such a ground fault of the cable is more difficult to visually detect than in the case of a bare conductor, and it is difficult to quickly find a fault point.

  For this reason, when the DC high voltage grounding relay 90 is operated, the worker in charge of restoration mainly searches the ground fault in the DC circuit on the secondary side of the rectifier 97. When a fault occurs, a lot of time is required to search and remove the fault point and to restore the substation, and there is a problem that the operation of the train is greatly affected.

  The present invention has been made in consideration of the above-mentioned matters, and the purpose thereof is the case where a ground fault occurs in the connecting wire between the rectifier transformer and the rectifier of the DC railway substation and the DC bus High-voltage earthing for DC railway substations that can be isolated in the event of a ground fault, and can quickly search for and eliminate fault points and restore power to substations, thus minimizing the impact on train operation. It is to provide a relay.

  In order to solve the above problems, the first invention is provided with a potential difference measurement unit provided between the ground mat and return line of the DC railway substation and measuring the potential difference between the ground mat and return line In a DC high-voltage grounding relay that uses a potential difference to determine a ground fault, measure the current flowing to the grounding conductor connected to the conductor support of the connecting wire between the rectifier transformer and the rectifier or the shielding tank of the connecting wire. A current measurement unit, a third harmonic extraction unit for extracting a third harmonic component from a measured value of the current, and one of the rectifiers when the extracted third harmonic component exceeds a threshold value An AC-side ground fault determination output unit that determines a ground fault on the next-side electrical path (AC side), and an AC-side ground fault display unit that displays this AC-side ground fault determination Provide a high voltage grounded relay. (Claim 1)

  In general, a DC high voltage grounding relay is intended for protection of a ground fault on the secondary side of the rectifier in a DC power station substation, but the primary side of the rectifier between the rectifier transformer and the rectifier It also operates due to a ground fault on the power path (AC side).

  FIG. 14 is a diagram showing the flow of current flowing when a ground fault occurs on the primary side electrical path (AC side) of the rectifier shown in FIG. As shown in FIG. 14, when a ground fault occurs on the primary side electrical path (AC side) of the rectifier 97, the ground mat 91 passes through the ground fault resistance 98R 'and the ground wire 98, and further, the ground resistance 91R. And a true ground 99, a rail leakage resistance 92R and a rail, and a return circuit 92, a circuit of current returning to the rectifier 97. For this reason, since the ground mat 91 has a positive (+) potential from the direction of each rectifying element of the rectifier 97, even if there is a ground fault in the primary side electrical path (AC side) of the rectifier, the DC high voltage ground relay 90 There is a characteristic to operate.

  FIG. 15 shows the result of frequency analysis of the current flowing in the ground wire 98 to which the shield layer of the connecting wire between the rectifier transformer 96 and the rectifier 97 in FIG. 14 is connected. It is understood that, in addition to the current of the commercial frequency (fundamental wave current), a current of the third harmonic component, a harmonic current accompanying the rectifying action of the rectifier 97, and the like flow through the current flowing through the And, as apparent from comparison with FIG. 13, the third harmonic current is a current which hardly exists unless there is a ground fault in the primary side electrical path of the rectifier.

  The present invention focuses on the third harmonic component, and uses this third harmonic component as an index to detect a ground fault on the primary side electrical path (AC side) of the rectifier, This makes it possible to determine a ground fault on the primary side of the rectifier with high accuracy.

  The high voltage earthing relay for a DC electric iron substation according to the first invention has a shielding layer of an electric path support or connecting line of a connecting wire between a rectifier transformer and a rectifier due to a ground fault on the primary side electric path (AC side) of the rectifier. The current measurement unit measures the current flowing through the connected ground line, and the third harmonic extraction unit extracts the third harmonic component of the current, whereby the extracted third harmonic component is When the threshold value is exceeded, the AC side ground fault determination output unit can determine a ground fault on the primary side electrical path (AC side) of the rectifier, and the AC side ground fault display unit can display the AC side ground fault determination. .

  Since the AC side ground fault judgment is displayed on the AC side ground fault display section, it is likely that the cause is on the DC side (ie, DC bus) of the rectifier or the AC side (ie, when the high voltage grounding relay for the DC power iron substation operates). And the ability to determine if there is a connecting wire between the rectifier transformer and the rectifier, so that the time to search for a failure point can be shortened, and a power recovery of the substation can be promptly performed to reduce the influence on the operation of the train. it can.

  The high-voltage grounding relay for the DC railway substation is a current measuring unit for detecting the occurrence of a ground fault on the primary side electric path (AC side) of the rectifier, a third harmonic extraction unit, an AC side ground fault judgment output unit And a high voltage earthing relay for a DC power iron substation provided with an AC side ground fault indicator may be configured separately from a conventional DC high voltage earthing relay, or may be added to an existing DC high voltage earthing relay to form a primary side of the rectifier It is possible to determine a ground fault on the (AC side).

  A second invention has a potential difference measurement unit provided between a ground mat and a return line of a DC railway substation and measuring a potential difference between the ground mat and the return line, and using the measured potential difference to ground In a DC high-voltage grounding relay for determining a failure, a third harmonic extraction unit for extracting a third harmonic component from a measured value of the potential difference, and the extracted third harmonic component exceed a threshold An AC side ground fault determination output unit that determines a ground fault on the primary side electrical path (AC side) of the rectifier, and an AC side ground fault display unit that displays the AC side ground fault determination. High voltage earthing relay for DC railway substation. (Claim 2)

  The third harmonic current that flows to the ground line due to a ground fault on the primary side of the rectifier (AC side) flows to the true ground via the ground mat and the ground resistance, and to the rail via the rail leakage resistance. Reflux. As a result, the third harmonic voltage is generated at both ends of the high voltage earthing relay for a DC railway substation connected between the grounding mat and the return line. This voltage is extracted by the third harmonic extraction unit, and when the extracted third harmonic component exceeds the threshold value, the AC side ground fault judgment output unit generates a ground fault in the primary side electrical path of the rectifier. Judgment promptly, and output AC side ground fault judgment. Next, the AC side ground fault display unit displays the AC side ground fault determination. Therefore, it is possible to shorten the failure point search time by allowing the worker involved in restoration to determine whether the cause is on the DC side or the AC side of the rectifier when the high voltage earthing relay for DC railway substation operates. Can be quickly recovered to reduce the impact on train operations.

  A third invention has a potential difference measurement unit provided between a ground mat and a return wire of a DC railway substation and measuring a potential difference between the ground mat and the return wire, and using the measured potential difference to ground A third harmonic extraction unit for extracting a third harmonic component of the measured potential difference in a direct current and high voltage grounding relay for determining a failure, and an electrical path support of a connecting wire between a transformer for a rectifier and a rectifier Or a current measurement unit that measures the current flowing to the ground wire to which the shield layer of the connection wire is connected, and one of the rectifiers when the measured value of this current and the extracted third harmonic component both exceed a threshold An AC-side ground fault determination output unit that determines a ground fault on the next-side electrical path (AC side), and an AC-side ground fault display unit that displays this AC-side ground fault determination Provide a high voltage grounded relay. (Claim 3)

  A current that flows to the ground line due to a ground fault on the primary side of the rectifier (AC side) flows to the true ground via the ground mat and the ground resistance, and then returns to the rail via the rail leakage resistance to the ground mat. A voltage is generated across the high voltage earthing relay for a DC railway substation connected between H. and the return line. The third harmonic component extracted from this voltage is compared with a threshold value to perform ground fault determination, thereby rapidly determining a ground fault on the primary side electrical path of the rectifier.

  However, the third harmonic component of the potential difference measured by the potentiometric measurement unit is affected by the ground fault of the primary side of the rectifier in the adjacent substation. When a ground fault occurs on the primary side of the rectifier of the adjacent substation, the ground current including the third harmonic component flows in the circuit where the ground current in the adjacent substation returns, but in that case Generates a rail potential including the third harmonic component. Since the rail potential is propagated and the potentiometric measurement unit of the present invention is affected, the ground current is flowing to the ground line of the own substation because the current flowing to the ground line exceeds a preset threshold. By detecting that the output of the third harmonic extraction unit connected to the potentiometric measurement unit exceeds a preset threshold together, thereby more reliably ensuring the primary side of the rectifier A ground fault on the (AC side) can be detected and displayed. As a result, when it is possible to determine whether the cause is on the DC side or the AC side of the rectifier when the high voltage ground relay for the DC rail substation operates, the failure point search time can be shortened, and power recovery of the substation is promptly performed. Can reduce the impact on train operations.

  A fourth invention has a potential difference measurement unit provided between the ground mat and the return wire of the DC railway substation and measuring a potential difference between the ground mat and the return wire, and using the measured potential difference to ground In the DC high-voltage grounding relay for determining a failure, a return current measurement unit that measures the current flowing to the return, and a third harmonic extraction unit that extracts the third harmonic component of the measured return current And an AC side ground fault determination output unit that determines a ground fault on the primary side electrical path of the rectifier when the extracted third harmonic component exceeds a threshold, and the AC side ground fault determination A high voltage ground relay for a direct current railway substation characterized by comprising: an AC side ground fault display unit. (Claim 4)

  The ground fault current generated by the ground fault on the primary side of the rectifier (AC side) flows to the ground wire and the ground mat via the ground fault resistance, and to the true earth via the ground resistance, and also to the rail leak Since the current is returned to the rectifier from the rail and return via resistance, the return current measurement unit is provided for return, and the third harmonic extraction unit extracts the third harmonic component of the measured return current. It is possible to detect a ground fault on the primary side electrical path (AC side) of the rectifier when the third harmonic component exceeds the threshold value, and display it on the AC side ground fault display unit. Therefore, a worker involved in restoration can shorten the failure point search time by being able to determine whether the cause is on the DC side or the AC side of the rectifier when the high voltage earthing relay for the DC railway substation operates, and the fault point search time can be shortened. Power can be delivered quickly to reduce the impact on train operations.

  In addition, a ground fault may occur due to a small animal or the like on the primary side electrical path (AC side) of the rectifier. In this case, the ground fault current may flow to the ground mat through the housing or the support metal, etc., so it may not flow through the ground line connected to the electrical path support of the connection line or the shield layer of the connection line. . For this reason, even if the current measurement unit is provided on the grounding wire, the ground fault current may not be detected, but similar refluxing occurs after the grounding mat, so a cable with a shielding layer is used for the primary side electrical path of the rectifier. The same phenomenon occurs as in the case. Therefore, by providing the current measurement portion in the return line, it is possible to determine the ground fault in this portion regardless of the state of the ground fault in the primary side electrical path (AC side) of the rectifier.

  As described above, according to the high voltage earthing relay for DC power transmission line substation of the first invention, the characteristic of the ground electric current flowing to the ground line when the ground electric fault occurs in the primary side electric path (AC side) of the rectifier The included third harmonic component can be used to reliably detect that a ground fault has occurred on the AC side of the rectifier. As a result, ground faults on the primary side of the rectifier can be promptly detected and displayed, so that the failure point search time can be shortened, power restoration of the substation can be promptly performed, and the influence on train operation can be reduced. Can.

  According to the second invention, the high voltage earthing relay for the DC electric iron substation according to the present invention, the ground mat and the return wire are generated by the third harmonic current which flows characteristically to the earthing wire due to the earth fault on the primary side electric path (AC side) of the rectifier. The third harmonic voltage generated at both ends of the high voltage earthing relay for DC power iron substations connected between them can be extracted and distinguished by the AC side ground fault judgment output unit, so that the ground fault on the primary side electric path of the rectifier Since the failure can be promptly determined and displayed, the failure point search time can be shortened, and the power recovery of the substation can be promptly performed to reduce the influence on the operation of the train.

  According to the high-voltage ground relay for a direct current railway substation of the third invention, between the ground mat and the return wire by the third harmonic current flowing to the ground wire due to the ground fault of the primary side electric path (AC side) of the rectifier. The third harmonic voltage characteristically generated at both ends of the high voltage earthing relay for the DC power iron substation connected to can be extracted and discriminated by the AC side ground fault judgment output unit. In addition, the output of the current measuring unit provided on the grounding wire connected to the electric path support of the connecting wire between the rectifier transformer and the rectifier or the shielding layer of the connecting wire exceeds a preset threshold value. By filling both, malfunction due to the influence of the rail potential generated by the ground fault on the primary side electrical path (AC side) of the rectifier between the rectifier transformer and the rectifier in the adjacent substation is suppressed, and the own substation with high accuracy. Since a ground fault on the primary side of the rectifier (AC side) can be detected and displayed, whether the cause is on the DC side of the rectifier when the high voltage grounding relay for DC iron substation operates, the AC side It is possible to shorten the failure point search time by being able to determine whether it is in, to quickly recover power in the substation, and to reduce the influence on the operation of the train.

  According to the high-voltage earthing relay for a DC electric iron substation according to the fourth invention, when the circuit causes a ground fault on the primary side electric path (AC side) of the rectifier, the earth current flowing in the ground line and the housing directly The third harmonic component contained in the ground current flowing to the ground mat can be detected on the return line side. As a result, ground faults on the primary side of the rectifier can be promptly detected and displayed, so that the failure point search time can be shortened, power restoration of the substation can be promptly performed, and the influence on train operation can be reduced. Can.

It is a figure which shows the structure of the substation for direct current irons in which the high voltage | pressure earthing relay for direct current electric wire substations concerning 1st Embodiment is installed. It is a figure which shows the circuit structure of the high voltage | pressure earthing relay for direct current electric wire substations concerning 1st Embodiment. It is a figure which shows the circuit structure of the high voltage | pressure earthing relay for direct current electric wire substations concerning 2nd Embodiment. It is a figure which shows the circuit structure of the high voltage | pressure earthing relay for DC electric iron substations of this 3rd Embodiment. It is a figure which shows the circuit structure of the high voltage | pressure earthing relay for direct current electric wire substations which becomes a modification of FIG. It is a figure which shows the structure of the substation for direct current irons in which the high voltage | pressure earthing relay for direct current electric wire substations concerning 4th Embodiment is installed. It is a figure which shows the circuit structure of the high voltage | pressure earthing relay for direct current electric wire substations concerning 4th Embodiment. It is a figure which shows the circuit structure of the high voltage | pressure earthing relay for direct current electric wire substations concerning 5th Embodiment. It is a figure which shows the circuit structure of the high voltage | pressure earthing relay for direct current electric wire substations concerning 6th Embodiment. It is a figure which shows the circuit structure of the high voltage | pressure earthing relay for direct current electric wire substations concerning 7th Embodiment. It is a figure which shows the circuit structure of the high voltage | pressure earthing relay for direct current electric wire substations concerning 8th Embodiment. It is a figure which shows the structure of the DC railway substation where the conventional DC high voltage | pressure earthing relay is installed. It is a figure which shows the harmonic component of the electric current which flows into a grounding wire at the time of a healthy state. (Indicates the content of each harmonic component to the effective value of the ground wire current.) It is a figure explaining the flow of electric current when a ground fault occurs in the connection line (AC side) between the transformer for rectifiers of a direct current railway substation, and a rectifier. It is a figure which shows the harmonic component of the electric current which flows into a ground wire, when a ground fault generate | occur | produces in the connection line (AC side) between the transformer for rectifiers and rectifier of DC rail substation. (Indicates the content of each harmonic component to the effective value of the ground wire current.)

  Hereinafter, a specific embodiment of a high voltage earthing relay for a direct current iron substation according to a first embodiment of the present invention will be described in detail with reference to the drawings, using FIGS. 1 to 2. As shown in FIG. 1, the high voltage earthing relay 1 for DC railway substation is provided between the ground mat 3 and the return wire 4 of the substation 2 and is a potentiometric measurement for measuring the potential difference between the ground mat 3 and the return wire 4 It has the part 5 and the ground fault determination output part 6 which determines a ground fault using the measured electrical potential difference.

  As shown in FIG. 2, a ground fault judgment output unit 6A for DC ground fault detecting a ground fault in a DC bus, and a ground fault on a circuit between the rectifying transformer 7 and the rectifier 8 are detected. And a ground fault judgment output unit 6B for AC ground fault. That is, the high voltage earthing relay 1 for a DC power iron substation according to the present embodiment measures the current flowing in the ground wire 10 to which the shielding layer 9s of the connecting wire 9 between the rectifier transformer 7 and the rectifier 8 of the substation 2 is connected. And a third harmonic extraction unit 12 comprising a filter circuit for extracting a third harmonic component from the measured value of the current, and the AC side ground fault judgment output unit 6B When the extracted third harmonic component exceeds the threshold value, the ground fault of the primary side of the rectifier is determined. The connecting wire 9 is a conductor serving as a core, a coating 9i made of an insulating material for protecting the conductor, a shielding layer 9s provided so as to cover the outside of the coating 9i, and an outer coating for protecting the shielding layer 9s. It is a cable provided with 9p. Therefore, the conductor and the shield layer 9s are connected via the large insulation resistance 10r by the coating 9i, but when a ground fault occurs in the connection line 9, the ground resistor 10r is smaller between the conductor and the shield layer 9s. Connected by '.

  Reference numeral 13 denotes a ground fault display unit for displaying the ground fault judgment from the ground fault judgment output unit 6, and 13A displays the ground fault judgment output from the ground fault judgment output unit 6A for the DC side ground fault failure. The DC side ground fault display unit 13B outputs the ground fault judgment between the rectifying transformer 7 and the rectifier 8 (the primary side of the rectifier 8) of the ground fault judgment output unit 6B for the AC side ground fault. It is an AC side ground fault display unit that displays a ground fault determination when it occurs.

  As shown in FIGS. 1 and 2, G is a true ground, 3r is a ground resistance of the ground mat 3, 5r is a voltage dividing resistance of the potential difference measurement unit, 4r is between the return wire 4 and the rail and the true ground G. Rail leakage resistance 5d is a diode for backflow prevention, and when the ground fault judgment output unit 6 outputs a ground fault judgment, the AC breaker 7A and the DC high speed breaker 14 shut off the circuit and the DC bus Stop the power supply to 15.

  1 and 2 differs from the conventional DC high voltage grounding relay 1 in that the high voltage grounding relay 1 for DC power iron substation differs from the conventional DC high voltage grounding relay in that the shielding layer 9s of the connecting wire 9 between the rectifier transformer 7 and the rectifier 8 is connected Since the current measurement unit 11 measures the current flowing through the line 10 and the third harmonic extraction unit 12 extracts and constantly monitors the third harmonic component, the primary side electrical path (AC side) of the rectifier 8 When the ground fault occurs, the third harmonic component exceeds a preset threshold value, causing the ground fault in the AC side ground fault judgment output unit 6B in the primary side electrical path of the rectifier 8 , And outputs the AC ground fault determination, which can be displayed on the AC ground fault display unit 13B.

  On the other hand, when a ground fault occurs in the secondary side electric path (DC side) of the rectifier 8, the current of the third harmonic component hardly exists in the current measurement value by the current measuring instrument, and the third harmonic Since there is almost no output from the extraction unit 12, the AC-side ground fault determination output unit 6B does not output the AC-side ground fault determination, and the display on the AC-side ground fault display unit 13B is not performed.

  That is, in FIG. 2, a portion surrounded by a virtual line indicated by reference numeral 1e is an extension circuit of the DC high-voltage grounding relay in the present invention, and in providing the extension circuit 1e including these members 11, 12, 6B, 13B, It differs from the conventional direct current high voltage grounding relay. Although this extended circuit 1e is preferably integrally formed as the high voltage earthing relay 1 for a DC power iron substation according to the present invention, it is provided to accompany a conventional DC high voltage earthing relay to provide a conventional DC high voltage earthing relay. It goes without saying that the grounding relay may be extended.

  As described above, when the potential difference measured by the potential difference measurement unit 5 exceeds the threshold set in advance, the high voltage ground relay 1 for a DC power iron substation according to the present invention outputs the ground fault determination output unit 6 (DC side ground fault determination output In the related art, the section 6A) outputs a determination output of a ground fault and displays it on the DC side ground fault display unit 13A and also shuts off the AC breaker 7A and the DC high speed breaker 14 to shut off the flow of fault current. While detecting the ground fault on the DC side of the rectifier similar to the DC high voltage ground relay, and when the site where this ground fault occurs is the primary side electrical path (AC side) of the rectifier 8, the ground fault judgment output Since the output from the part 6 (AC side ground fault judgment output part 6B) can be made and the same can be displayed on the AC side ground fault display part 13B, it is useful for performing the restoration of the substation more quickly.

  FIG. 3 is a diagram showing a circuit configuration of a high voltage ground relay for a DC power transmission iron substation according to a second embodiment of the present invention. In FIG. 3, reference numeral 20 denotes a high voltage ground relay for a DC railway substation according to the second embodiment. In addition, in FIG. 3, since the member which attached | subjected the code | symbol same as FIG. 1-FIG. 2 is the same or equivalent member, the detailed description is abbreviate | omitted.

  The third harmonic extraction unit 12 of the high voltage ground relay 20 for a direct current railway substation according to the present embodiment uses the measurement value of the potential difference between the ground mat 3 and the return wire 4 measured by the potential difference measurement unit 5 to obtain the third harmonic. The AC side ground fault judgment output unit 6B judges the ground fault on the AC side of the rectifier when the third harmonic wave component of the extracted potential difference exceeds a predetermined threshold. The AC side ground fault display unit 13B displays the AC side ground fault output and the AC side ground fault determination.

  In the high-voltage ground relay 20 for DC power iron substations configured as described above, when a ground fault occurs on the primary side electrical path of the rectifier 8, the ground current flows to the ground mat 3 via the ground resistor 10r 'and the ground wire 10. Furthermore, since a ground fault current flows in a circuit such as a return wire 4 and a rectifier 8 via the ground resistance 3r to the true ground G, and the rail leak resistance 4r, the ground mat 3 is connected to the return wire 4 A potential is generated at both ends of the potential difference measurement unit 5 due to the impedance from the ground mat 3 to the return wire 4.

  Further, since the ground current includes the third harmonic current, the third harmonic voltage is also generated at both ends of the potential difference measurement unit 5. Therefore, since the third harmonic component can be extracted from the output of the potentiometric measurement unit 5 and constantly monitored by the AC side ground fault judgment output unit 6B, the ground side fault of the primary side electrical path of the rectifier 8 can be generated. The occurrence of a ground fault on the primary side electrical path of the rectifier 8 can be detected by the third harmonic component exceeding a preset threshold value, and this can be displayed on the AC side ground fault display unit 13B. it can.

  When a ground fault occurs in the secondary side electric path (DC side) of the rectifier 8, the third harmonic component (voltage detection) hardly exists, and the output from the third harmonic extraction unit 12 is also There is almost no output or display of the ground fault judgment. As a result, the DC side of the same rectifier as the conventional DC high-voltage earthing relay that outputs a ground fault judgment output by exceeding the threshold value preset by the DC side ground fault judgment output unit 6A connected to the potential difference measurement unit 5 Ground fault detection operation can be performed.

  Also in the present embodiment, the third harmonic extraction unit 12 for extracting the third harmonic component from the output of the potential difference measurement unit 5, the AC side ground fault judgment output unit 6B and the AC side ground fault display unit 13B It is an expansion circuit (refer to the expansion circuit 1e in FIG. 2) for judging the AC side ground fault of the high voltage ground relay 20 for the railway substation, and whether these expansion circuits are integrally formed or separated (in this case, members It is needless to say that 5r, 5d, 5 need to be provided in another pair) and design change is possible arbitrarily.

  FIG. 4 is a view showing the configuration of a high voltage ground relay 30 for a direct current electric wire substation according to a third embodiment of the present invention. In FIG. 4, members given the same reference numerals as in FIGS. 1 to 3 are the same or equivalent members, and thus detailed description thereof will be omitted.

  The configuration of the high voltage ground relay 30 for DC power iron substation shown in FIG. 4 is a shield layer of the connecting wire 9 between the rectifier transformer 7 and the rectifier 8 in addition to the high voltage ground relay 20 for DC power iron substation shown in FIG. It differs in that it has the current measurement unit 11 that detects the current of the ground wire 10 to which the 9s is connected, and the third harmonic component of the output from the potential difference measurement unit 5 is converted to the third harmonic extraction unit It is identical in detecting a ground fault in the primary side electrical path of the rectifier 8 when the extraction is performed at 12 and the constant monitoring is performed and the preset threshold value is exceeded.

  The third harmonic component of the potential difference measured by the potential difference measurement unit 5 is affected by the ground fault of the primary side electrical path of the rectifier in the adjacent substation, and the ground fault in the primary side electrical path of the rectifier of the adjacent substation In the event of a failure, the ground fault current including the third harmonic component flows in the circuit where the ground fault current in the adjacent substation returns, but at that time the true ground G, the rail leak resistance 4r, the rail and the return As it passes through the line 4, a rail potential including the third harmonic component is generated.

  Then, since the potential of the rail is propagated and the potentiometric measurement unit 5 of the present invention connected to the return wire 4 is affected, it is considered that the third harmonic component at the output is also affected. In the present embodiment, in order to suppress a malfunction due to the influence of the adjacent substation, the current measurement unit 11 is provided on the ground wire 10 to which the shielding layer 9s of the connection wire 9 between the transformer 7 for the rectifier and the rectifier 8 is connected. , Constantly monitor the effective value of the ground wire current flowing through the ground wire 10, and when the output exceeds a preset threshold value, to the ground wire 10 of the substation 2 to which the high voltage ground relay 30 for DC railway substation is attached When it is determined that the ground fault current has flowed and the output of the third harmonic component and the AND condition hold, the influence of the rail potential from the adjacent substation is suppressed, and the primary side electrical path of the rectifier 8 (AC Side) ground fault can be detected.

  In addition, when a ground fault occurs in the secondary side electric path (DC side) of the rectifier, the third harmonic component hardly exists in the output of the potentiometric measurement unit 5, and the third harmonic extraction unit 12 The AC ground fault determination output and the AC ground fault display are not performed. As a result, in the conventional high voltage grounding relay for a direct current electric wire substation according to the present embodiment, a conventional ground judgment is output by exceeding a threshold preset by the DC side ground fault judgment output unit 6A connected to the potential difference measurement unit 5 It is possible to perform a detection operation of a ground fault on the DC side of the rectifier similar to the DC high voltage ground relay of

  FIG. 5 is a view showing a modified example of the high voltage earthing relay 30 for a direct current railway substation shown in FIG. The high voltage earthing relay 40 for the DC electric iron substation shown in FIG. 5 extracts the third harmonic component of the current measured by the current measurement unit 11 by the third harmonic extraction unit 12 and determines the AC side ground fault judging unit 6B. 4 is different from the high voltage grounding relay 30 for a DC power iron substation shown in FIG. 4, thereby the grounding wire 10 to which the shielding layer 9s of the connecting wire 9 between the rectifier transformer 7 and the rectifier 8 is connected. The third harmonic current of the current measured by the current measurement unit 11 provided in the is constantly monitored. As described above, as a method of determining that the ground fault current has flowed to the ground line 10, the third harmonic current may be used instead of the effective value of the ground line current.

  6 and 7 are views for explaining the fourth embodiment of the present invention, and FIG. 6 shows the configuration of a DC railway substation in which the high voltage ground relay 50 for a DC railway substation according to the fourth embodiment is installed. FIG. 7 is a diagram showing a circuit configuration of the high voltage earthing relay 50 for the DC railway substation. In these figures, members given the same reference numerals as in FIGS. 1 to 5 are the same or equivalent members, and therefore detailed description thereof will be omitted.

  The high voltage earthing relay 50 for a DC electric iron substation according to the present embodiment is provided with a return current measuring unit 51 for detecting a return current in the return wire 4 of the substation 2, and the third harmonic extraction unit 12 is a return wire. The third embodiment differs from the first embodiment shown in FIGS. 1 and 2 in that the third harmonic component of the retrace current measured by the current measurement unit 51 is extracted.

  That is, when a ground fault occurs on the primary side electric path of the rectifier 8, it flows to the ground mat 3 through the ground resistor 10r 'and the ground wire 10, and the ground resistor 3r, the true ground G, and the rail leak resistance 4r Since the ground fault current flows in a circuit that flows to the retrace 4 and the rectifier 8 via the circuit, the return current measured by the retrace current measuring unit 51 is also provided when the retrace current measuring unit 51 is provided in the retrace 4 The line current is characterized in that a large number of third harmonic components occur when a ground fault occurs on the primary side electrical path (AC side) of the rectifier 8.

  In addition, a ground fault may occur due to a small animal or the like on the primary side electrical path (AC side) of the rectifier. In this case, the ground fault current may flow to the ground mat 3 through the housing and the support metal, etc. After the ground mat 3, the ground resistance 3r, the true ground, the return wire 4 through the rail leak resistance 4r, and the rectifier A ground fault current flows in a circuit that flows to 8. Therefore, by providing the return current measurement unit 51 in the return line 4 as in the present embodiment, the return line is independent of the ground fault condition of the connection line 9 between the rectifier transformer 7 and the rectifier 8. Since the characteristic unique to the ground fault in the primary side electrical path of the rectifier 8 appears in the retrace current measured by the current measuring unit 51, the occurrence of the ground fault in this portion can be determined with certainty.

  By constantly monitoring the third harmonic component of the return current, the third harmonic component exceeds a preset threshold value when a ground fault occurs in the primary side electrical path of the rectifier 8 This ground fault determination can be performed, and the AC side ground fault determination output and the AC side ground fault determination display can be performed. When a ground fault occurs on the secondary side electrical path (DC side) of the rectifier, there is almost no third harmonic current and there is almost no output from the third harmonic extraction unit, so the AC side Neither the ground fault judgment output nor the AC side ground fault judgment display is performed.

  As a result, when the high voltage earthing relay 50 for a DC electric wire substation according to the fourth embodiment exceeds the threshold preset by the DC side ground detection output unit 6A connected to the potential difference measurement unit 5, the DC side ground leakage is detected. It is possible to perform a detection operation of a ground fault on the DC side of the rectifier similar to that of the conventional DC high voltage ground relay that outputs a determination.

  In each of the above-described embodiments, the ground fault display unit 13 includes a DC side ground fault display unit 13A that displays a ground fault on the DC side of the rectifier, and an AC side ground fault display that displays the ground fault on the AC side of the rectifier. Although the example which has two types of outputs of section 13B is shown and it is possible to judge at which site a ground fault has occurred at a glance by this, it is preferable, but the present invention is limited to this point It is needless to say that it is not a thing. That is, the ground fault display unit 13 may use a single display that performs different display when the ground fault occurs on the AC side and the ground fault occurs on the DC side.

  In each embodiment of the present invention, when a ground fault occurs on the primary side electrical path (AC side) of the rectifier, not only the AC side ground fault judgment output unit 6B but also the DC side ground fault judgment output unit 6A Although there is a characteristic that operates, for example, when only the DC side ground fault judgment output unit 6A operates, it is judged as a ground fault of the DC side electric path of the rectifier, the output of the DC side ground fault judgment unit 6A and the AC side ground fault When both of the determination units 6B operate, it is determined that there is a ground fault in the AC side of the rectifier, and when only the AC side ground determination unit 6B operates, wear and damage such as insulation deterioration of the AC side of the rectifier and It can also be used for maintenance of substation equipment as an alarm that requires judgment and inspection. Therefore, it is needless to say that the ground fault judgment output unit 6 does not have to be divided into the alternating current side and the direct current side, and may be integrated into one.

  FIG. 8 is a diagram showing the configuration of a high voltage earthing relay 60 for a DC electric wire substation according to a fifth embodiment of the present invention, and the high voltage earthing relay 60 for a DC electric steel transformer station of this example is the first shown in FIGS. What determines the ground fault of the connecting wire 9 between the transformer 7 for a rectifier of one embodiment and the rectifier 8 and displays it on the ground fault display section 13B (a signal for operating the AC breaker 7A as shown in FIG. 1 Ground detector may not be output). In addition, since the structure is equivalent to what was already explained in full detail in FIG. 1, FIG. 2, the detailed description is abbreviate | omitted.

  The high voltage earthing relay 60 for a DC electric iron substation according to the present embodiment always keeps the third harmonic component of the current flowing in the earthing wire 10 to which the shielding layer 9s of the connecting wire 9 between the rectifier transformer 7 and the rectifier 8 is connected. Since it can be monitored, if a ground fault occurs in the primary side electrical path of the rectifier 8, the ground fault occurs in the primary side electrical path of the rectifier 8 when the third harmonic component exceeds a preset threshold value Can be detected, and the AC side ground fault determination output and the AC side ground fault display can be performed.

  FIG. 9 is a view showing the configuration of a high voltage earthing relay 70 for a DC electric wire substation according to a sixth embodiment of the present invention, and the high voltage earthing relay 70 for DC electric steel transformer station of this example is a second embodiment shown in FIG. For determining a ground fault on the connection line 9 between the rectifier transformer 7 and the rectifier 8 and displaying on the AC side ground fault display unit 13B (a ground fault that does not output a signal for operating the AC breaker 7A or the like) (May be a detector). In addition, since the structure is equivalent to what was already explained in full detail in FIG. 3, the detailed description is abbreviate | omitted.

  The high voltage earthing relay 70 for the DC power iron substation according to the present embodiment extracts the third harmonic component from the output of the potentiometric measurement unit 5 and can constantly monitor the magnitude of the extracted third harmonic voltage. When the primary side electrical path of the ground fault occurs, the third harmonic component exceeds a preset threshold to detect that the ground fault has occurred on the primary side electrical path of the rectifier, and Side ground fault determination output and AC side ground fault display can be performed.

  FIG. 10 is a diagram showing the configuration of a high voltage earthing relay 80 for a DC electric wire substation according to a seventh embodiment of the present invention, and the high voltage earthing relay 80 for DC electric steel transformer station of this example is the third embodiment shown in FIG. For determining a ground fault on the connection line 9 between the rectifier transformer 7 and the rectifier 8 and displaying on the AC side ground fault display unit 13B (a ground fault that does not output a signal for operating the AC breaker 7A or the like) (May be a detector). In addition, since the structure is equivalent to what was already explained in full detail in FIG. 4, the detailed description is abbreviate | omitted.

  The high voltage earthing relay 80 for a direct current electric wire substation according to the present embodiment has a current measuring unit 11 for detecting the current of the earthing wire 10 to which the shielding layer 9s of the connecting wire 9 between the rectifier transformer 7 and the rectifier 8 is connected. The third harmonic component of the output from the potential difference measurement unit 5 is extracted, and the magnitudes of the extracted third harmonic voltage and the current are constantly monitored by the AC side ground fault judgment output unit 6B. Since the occurrence of a ground fault on the primary side electrical path of the rectifier is detected by exceeding the set threshold together, the AC side is detected when the primary side electrical path of the rectifier causes a ground fault. Ground fault determination output and AC side ground fault display can be performed.

  FIG. 11 is a diagram showing the configuration of a high voltage earthing relay 85 for a DC electric wire substation according to an eighth embodiment of the present invention, and the high voltage earthing relay 85 for DC electric steel transformer station of this example is the first shown in FIGS. 4. A ground fault of the connection line 9 between the rectifier transformer 7 and the rectifier 8 of the fourth embodiment is determined and displayed on the AC side ground fault display unit 13B (does not output a signal for operating the AC breaker 7A or the like) It may be a ground fault detector). In addition, since the structure is equivalent to what was already explained in full detail in FIG. 7, the detailed description is abbreviate | omitted.

  The high voltage earthing relay 85 for the DC electric iron substation according to the present embodiment extracts the third harmonic component of the return current flowing to the return wire 4 and constantly monitors it by the AC side ground fault judgment output unit 6B, and sets a preset threshold. Is to detect the occurrence of a ground fault on the primary side of the rectifier, so even if the ground fault on the primary side of the rectifier is due to a small animal or the like, or the shield layer Even if it is due to the insulation deterioration of the attached cable, the AC side ground fault determination output and the AC side ground fault display can be performed when a ground fault occurs regardless of the situation.

1, 20, 30, 40, 50, 60, 70, 80, 85 High-voltage grounding relay for DC power iron substation 2 substation 3 grounding mat 4 return 5 potential difference measuring unit 6 ground fault judgment output unit 6A DC side ground fault judgment output Part 6B AC side ground fault judgment output part 7 Transformer for rectifier 8 Rectifier 9 Connection wire 9s Shielding layer 10 Ground wire 11 Current measurement part 12 3rd harmonic extraction part 13 Ground fault display part 13A DC side ground fault display part 13B AC side ground fault display unit 51 Return current measurement unit

Claims (4)

  A direct current determination circuit provided between the ground mat and the return line of the DC railway substation for measuring a potential difference between the ground mat and the return line, and determining a ground fault by using the measured potential difference. In a high voltage grounding relay, a current measuring unit for measuring a current flowing to a ground wire to which a wire support of a connecting wire between a rectifier transformer and a rectifier is connected or a shielding layer of the connecting wire is connected; A third harmonic extraction unit for extracting a third harmonic component, and a primary circuit of a rectifier between the rectifier transformer and the rectifier when the extracted third harmonic component exceeds a threshold An AC side ground fault determination output unit that determines a ground fault on the (AC side), and an AC side ground fault display unit that displays this AC side ground fault determination .   A direct current determination circuit provided between the ground mat and the return line of the DC railway substation for measuring a potential difference between the ground mat and the return line, and determining a ground fault by using the measured potential difference. In a high voltage grounded relay, a third harmonic extraction unit for extracting a third harmonic component from a measured value of the potential difference, and transformer transformation for when the extracted third harmonic component exceeds a threshold value. An AC-side ground fault determination output unit that determines a ground fault on the primary side electrical path (AC side) of a rectifier between the inverter and the rectifier, and an AC-side ground fault display unit that displays this AC-side ground fault determination High-voltage grounding relay for DC railway substation characterized by   A direct current determination circuit provided between the ground mat and the return line of the DC railway substation for measuring a potential difference between the ground mat and the return line, and determining a ground fault by using the measured potential difference. In a high voltage grounded relay, a third harmonic extraction unit for extracting a third harmonic component of the measured potential difference, and shielding of an electric path support or a connecting wire of a connecting wire between a rectifier transformer and a rectifier Between the rectifier transformer and the rectifier when the measured value of the current and the extracted third harmonic component both exceed the threshold value, and a current measuring unit that measures the current flowing to the ground wire to which the layer is connected An AC-side ground fault determination output unit that determines a ground fault on the primary-side electrical path (AC side) of the rectifier, and an AC-side ground fault display unit that displays the AC-side ground fault determination. High-voltage grounding relay for DC railway substations.   A direct current determination circuit provided between the ground mat and the return line of the DC railway substation for measuring a potential difference between the ground mat and the return line, and determining a ground fault by using the measured potential difference. In the high-voltage grounded relay, a retrace current measuring unit for measuring the current flowing to the retrace, a third harmonic extraction unit for extracting the third harmonic component of the measured retrace current, and the third harmonic extraction unit An AC side ground fault determination output unit that determines a ground fault on the primary side electrical path (AC side) of the rectifier between the rectifier transformer and the rectifier when the third harmonic component exceeds the threshold value; What is claimed is: 1. A high voltage grounding relay for a direct current railway substation, comprising: an alternating current side ground fault display unit for displaying an alternating current side ground fault determination.

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