JPH08205377A - Protective device for feeding equipment - Google Patents

Abstract

PURPOSE: To provide a protective device for feeding equipment which can surely detect the generation of an accident current, facilitate the maintenance, and stabilize the operation. CONSTITUTION: A current transformer 38 and a breaker 36 are connected to each of a supply circuit SC for supplying d.c. power to a d.c. bus DB and a d.c. circuit DC for supplying the d.c. power supplied to the d.c. bus DB further to respective feeding electric wires L, and further an auxiliary contact 56 for detecting the open and close state of the breaker 36 is provided for every breaker 36. A control device 18 performs the processing of unusual detection such as the ground fault detection of the d.c. bus DB, the reverse current detection of the supply circuit SC and the unbreakable detection of the breaker 36 on the basis of the detection result of the current transformer 38 and the auxiliary contact. As a result, since an arc detector and the like which are conventionally used for this kind of processing, have large aged deterioration and take time for maintenance become unnecessary, maintenance becomes easy and operation becomes stable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention detects the occurrence of fault currents such as overcurrent and reverse current caused by short circuit accidents of feeder lines and other facilities in feeding facilities such as DC substations for electric railways. The present invention relates to a feeder protection device for cutting off the accident current and protecting the feeder.

[0002]

2. Description of the Related Art Conventionally, in a DC substation installed in a DC electrification section of a railway and supplying DC electric power for operation to a train via a feeder, a predetermined feeder is provided for each direction and upper and lower lines. The feeding circuit that distributes the DC power of is configured as shown in FIG. 11, for example.

That is, the feeder circuit has a plurality of supply lines SC for supplying the DC power of a predetermined voltage output from the transformer circuit 80 to the DC bus DB, and one end thereof connected to the DC bus DB.
A plurality of direct current lines DC, the other ends of which are respectively connected to the electric wire L via a disconnector 82, and one end of which is connected to a direct current bus DB,
The other end is composed of a protection line BC connected to the common bus CB. Then, each of the lines SC, DC, and BC opens the contacts to cut off the current when a large current of a predetermined amount or more flows in the DC bus DB due to an accident or the like, or when an opening command from the outside is input. It is connected via a circuit breaker 84. Further, the supply line SC is connected with a reverse current relay 86 for detecting a reverse current, and the DC line DC and the backup line BC are each provided with a failure selecting device 88 for detecting a short circuit of the feeder line L.
And a direct current ammeter 90 with a residual pointer for detecting a current value flowing in each line DC, BC and a peak value thereof are connected,
Further, in the vicinity of each breaker 84, an arc detector 92 for determining whether or not the current can be reliably cut off by detecting an arc generated when the contact of the breaker 84 is opened was provided.

The arc detector 92 is composed of a photocell that detects the ultraviolet rays radiated when an arc occurs and outputs a predetermined voltage according to the intensity of the ultraviolet rays. Also,
The backflow relay 86, the failure selection device 88, and the DC ammeter 90 with a residual pointer are respectively connected to the lines SC and D via the current transformer.
It is connected to C and BC. Further, the common bus BC is connected to each feeder L via a disconnector 94, and a surge arrester 96 is provided on the feeder L side of each disconnector 82, 94.

The reverse relay 86 and the failure selection device 8
8. When the arc detector 92 detects an abnormality, each of them individually outputs an opening command to a predetermined circuit breaker 84 to open the circuit breaker 84 so that abnormal current continues to flow. I tried to prevent it and protect the equipment.

[0006]

By the way, the circuit breaker 84
Is usually housed in a predetermined circuit breaker chamber because the arc generated when the contact is opened may cause a fire or the like if it comes into contact with another object.
No. 2 was also installed in this breaker room. For this reason, when inspecting the arc detector 92, it is necessary to enter the circuit breaker room, and it is dangerous to enter the circuit breaker room in an operating state in which a high voltage is applied. Therefore, it is necessary to shut down the equipment. There was a problem that it was very time-consuming.

Further, since the photocells forming the arc detector 92 have directivity, it is necessary to adjust the mounting position and the mounting angle with accuracy, and the output deteriorates due to deterioration over time, so that the output is always stable. To ensure detection capability,
It is necessary to perform an operation test on a regular basis for adjustment, and there is a problem in that mounting and maintenance are troublesome.

Further, the reverse relay 86 and the failure selecting device 8
8. Since the arc detectors 92 individually detect the abnormality, there is a problem that the ground fault of the DC bus DB cannot be detected. That is, when the DC bus DB is grounded (so-called ground fault) via a certain amount of resistance due to some cause, and a fault current of about a load current flows out from the DC bus DB,
No current, which is judged to be abnormal, flows in each of the lines SC, DC, BC connected to the DC bus DB. Therefore, each line SC, DC, BC individually detects the abnormality. Therefore, it is impossible to distinguish between the load current and the fault current, and the ground fault of the DC bus DB cannot be detected.

In order to solve the above problems, the present invention provides
An object of the present invention is to provide a protective device for feeding equipment that can reliably detect the occurrence of a fault current, can be easily maintained, and can be operated stably.

[0010]

In order to achieve the above-mentioned object, the invention according to claim 1 is connected to a plurality of feeders provided for supplying direct-current power used for driving a train. A plurality of direct-current lines, a direct-current bus bar connecting one end of each of the direct-current lines, and a contact provided for each direct-current line for cutting off the current flowing through the direct-current line. If more than a predetermined current flows through
Alternatively, a protection device for feeding equipment, which comprises a breaking means for opening the contact when an opening command is input from the outside, is provided for each DC line, and a current value flowing through the DC line. And current detecting means for detecting the current direction, and determining the abnormality of the current flowing in and out of the DC bus based on the current value and the current direction detected by the current detecting means, in the case of determining that there is an abnormality, And a calculation means for outputting an opening command to a predetermined cutoff means.

The invention described in claim 2 is the same as claim 1.
In the protective device for feeding equipment according to claim 7, the calculating means calculates a difference between a total current value flowing into the DC bus and a total current value flowing out from the DC bus, based on a detection result of the current detecting means. And a ground fault determination that determines whether or not the absolute value of the calculated value calculated by the calculating unit is equal to or greater than a predetermined value, and determines that there is an abnormality when the calculated value is equal to or greater than the predetermined value. Means and are provided.

Next, the invention described in claim 3 is the same as claim 1
Alternatively, in the feeder protection device according to claim 2,
Each of the breaking means is provided with a contact monitoring means for monitoring the operating state of the contact, and further, the computing means determines whether or not each of the breaking means is in an open state based on the detection result of the contact monitoring means. It is determined whether or not the current value detected by the current detecting means of the DC line having the open determining means for determining and the disconnecting means determined to be in the open state is a predetermined value or more, and the current value is the predetermined value. In the case of the above, it is characterized in that it is provided with a non-interruption judging means for judging that there is an abnormality.

[0013] Next, the invention according to claim 4 is the protective device for feeder equipment according to any one of claims 1 to 3, wherein at least one DC power supply is provided to the DC bus. A supply line, and a disconnection means provided on the supply line and for disconnecting the connection with the DC bus when a current more than a predetermined value flows in the supply line or when an opening command is input from the outside. A current detecting means for detecting a current value and an inflow / outflow direction of the current flowing through the supply line,
Further, the calculation means determines whether or not the current detected by the current detection means connected to the supply line is flowing in the power supply direction, and when the current is flowing in the direction opposite to the power supply direction. It is characterized in that a backflow judging means for judging that there is an abnormality is provided.

[0014]

In the feeder protection device according to claim 1 configured as described above, the current detecting means provided for each DC line has a current value and a current direction flowing through the DC line. And the computing means determines an abnormality in the current flowing in and out of the DC bus based on the current value and the current direction detected by the current detecting means, and when it determines that there is an abnormality, a predetermined shutoff means An open command is output to and the breaking means opens the contact to cut off the current.

As described above, by detecting the abnormality and opening the disconnecting means, it is possible to prevent the abnormal current from continuously flowing in the feeder equipment, thereby preventing the feeder equipment from being damaged by an accident current or the like. Can be protected from abnormal current. Further, it is sufficient that the current flowing through the DC line can be detected when determining the abnormality, and it can be easily detected by, for example, a current transformer. Moreover, since the current transformer hardly changes over time, stable detection can be performed and maintenance is easy.

Next, in the feeder protection device according to the second aspect of the present invention, the calculating means includes the calculating means and the ground fault determining means, and the calculating means is based on the detection result of the current detecting means. Then, the difference between the total current value flowing into the DC bus and the total current value flowing out from the DC bus is calculated, and the ground fault determining means,
It is determined whether or not the absolute value of the calculated value calculated by the calculating means is a predetermined value or more, and when the calculated value is a predetermined value or more, it is determined that the current flowing into or out of the DC bus is abnormal. In this case, it is determined that the DC bus bar has a ground fault.

Therefore, according to the present invention, it is possible to detect the ground fault of the DC bus which cannot be detected by the conventional device. That is, in the conventional device, the current value is detected for each line,
Since it was not possible to know the state of the DC bus to which each line was connected by making an individual error determination, by collecting the current value of each line and performing arithmetic processing,
The current value flowing in and out of the DC bus bar can be calculated, and the abnormality of the DC bus bar can be determined.

Next, in the feeder protection device according to the third aspect, the contact monitoring means is provided for each breaking means, and the computing means is provided with an open judging means and an unbreakable judging means. ing. Then, the contact monitoring means monitors the operation state of the contacts of the breaking means for each breaking means, and when the opening judging means judges that the breaking means is in the open state based on the detection result of the contact monitoring means, the breaking is made. Impossible judgment means,
It is determined whether or not the current value detected by the current detection means of the DC line having the disconnection means determined to be in the open state is equal to or greater than a predetermined value, and if the current value is equal to or greater than the predetermined value, the DC bus is connected. It is determined that the current flowing in and out is abnormal, and in this case, it is determined that the breaking means is in the unbreakable state.

That is, instead of directly detecting the arc generated when interruption is impossible as in the conventional device to determine the interruption impossible state, the interruption impossible state is determined based on the operating state of the contact and the current flowing through the DC line. are doing. Therefore, according to the present invention, the unbreakable state of the breaking means can be detected without using the arc detector.

Further, the contact monitoring means for monitoring the operating state of the contact may be any one as long as it outputs a binary value indicating opening / closing according to the operating position of the contact, and the current detecting means is also a current transformer or the like.
General equipment can be used. As described above, according to the present invention, since it is not necessary to use a special device such as an arc detector, which has a large change in detection performance over time and requires time and effort for maintenance, maintenance becomes easy and stable with little change over time. It is possible to judge the abnormality.

Further, in the feeder protection equipment according to the present invention, there is provided at least one supply line provided with a breaking means and a current detecting means, and the calculating means is
A backflow determining means is provided. Then, the backflow determination means
It is determined whether or not the current detected by the current detection means of the supply line is flowing in the power supply direction, and if the current is flowing in the direction opposite to the power supply direction, it is determined that there is an abnormality. Judge that the line current is flowing backward.

Therefore, according to the present invention, it is possible to detect the reverse current of the current in the supply line without providing the reverse relay. Further, the current detection means for detecting the current of the supply line,
Since it can also be used for detecting the ground fault of the DC bus, detecting the interruption of the interruption means, etc., if the current detection means is already provided for this purpose, the calculation means is simply provided with the backflow determination means. It is possible to easily realize the same function as the backflow relay.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is an explanatory diagram showing a schematic configuration of feeding system equipment provided for supplying driving DC power to a train in a DC electrification section of a railway.

As shown in FIG. 2, the feeding system equipment in the DC electrification section is a DC substation 2 and a DC substation 2 that receive AC power from the outside, convert it to a predetermined DC power and supply it to the feeder L.
When the DC substation 2 alone cannot secure the intermediate feeder voltage above a predetermined value, or when the feeder L is sorted, the feeder section 4 and the feeder section 4 are provided in the same manner. A feeder tie post 6 and the like provided to reduce the voltage drop of the feeder L is provided.

The feeder L is provided for each of the up and down lines, and a voltage is applied so that the feeder L has a positive pole and the rail R has a negative pole. Of these, the DC substation 2
As shown in FIG. 1, a power receiving circuit 8 for receiving extra-high voltage (for example, 22 KV, 66 KV, 77 KV, etc.) AC power from a power transmission line (not shown), and AC power received by the power receiving circuit 8 The transformation circuit 10 that takes in via the bus RB, transforms and rectifies it to convert it into a predetermined DC power (1500 V in this embodiment), and the AC power via the power receiving bus RB to turn on traffic lights and lights / power of each station. Voltage distribution circuit 1 for supplying a high voltage power source (for example, 6 KV) as a power source for
2, for smoothing the feeding circuit 14 that supplies the DC power obtained as the output of the transformer circuit 10 to each feeder L, and the DC output that is supplied from the transformer circuit 10 to the feeder through the feeder circuit 14. Smoothing circuit 16 and CPU, ROM, RA
An abnormality is determined based on a current flowing through each part of the feeder circuit 14 and an open / closed state of a circuit breaker 36, which will be described later, provided in the feeder circuit 14, and the abnormality is determined by a well-known microcomputer configured around M. If there is a specified circuit breaker 36
And a control device 18 for executing various processes such as outputting an opening command for opening the.

Of these, the transformer circuit 10 is the feeder circuit 14
Depending on the amount of electric power supplied to the power supply, or a plurality of power supply circuits are provided for backup in the event of an accident, each transformer circuit 10 includes an AC circuit breaker 20 that shuts off the fault current and protects the transformer circuit 10, and a disconnector. 22, a transformer 24 that transforms the received extra-high voltage AC power to a predetermined voltage (1200 V in this embodiment), a silicon rectifier 26 that rectifies the output of the transformer 24 and converts it to a predetermined DC (1500 V), AC interruption Connected by a current transformer 28 between the transformer 20 and the transformer 24, and configured by a short circuit selection relay 30, an overcurrent relay 32, etc., which detects a short circuit or ground fault from the change in the current flowing in the transformer circuit 10. Has been done.

Further, the feeder circuit 14 is a supply line S for supplying the DC power output from the transformer circuit 10 to the DC bus DB.
C, one end is connected to the DC bus DB, and the other end is the disconnector 3
A total of four DC lines DC connected to the feeder L via four lines, one for each direction and one for each upper and lower line, and a backup line BC with one end connected to the DC bus DB and the other end connected to the common bus CB. Consists of. The supply line SC, the DC line DC, and the backup line BC are connected to the DC busbar through a circuit breaker 36 that opens the contacts and cuts off the current when a current more than a predetermined value flows or an open command is input from the outside. In addition to being connected to DB, a current transformer 38 for detecting a current flowing through each of the lines SC and DC is also connected. In addition, each current transformer 38
Is output to the control device 18 via a signal line. Further, between the circuit breakers 36 and the control device 18, a signal line for notifying the control device 18 of the open / closed state of the circuit breaker 36 and an opening command for instructing the opening of the contacts of the circuit breaker 36 are provided. A signal line from 18 to the circuit breaker 36 is provided. Furthermore, DC line DC and backup line B
A fault selection device 40 for detecting a short circuit or the like of the feeder L is connected to C via a current transformer 42. Further, the common bus CB is connected to each feeder L via a disconnector 44, and an abnormal voltage due to lightning or the like is DC-transformed to the feeder L side of the disconnectors 34, 44 via the feeder L. A lightning arrester 46 for preventing the intrusion into the station 2 is connected to each.

The common bus CB is connected to the feeder line L via the backup line BC when the breaker 36 of each DC line DC or the like breaks down, or when power transmission is stopped for checking the DC line DC. It is provided in order to be able to continue the power supply of. Next, FIG. 3 is an explanatory diagram showing a schematic configuration of only a part of the circuit breaker 36 related to opening and closing of contacts related to the present invention.

As shown in FIG. 3, the circuit breaker 36 is connected to the fixed contact 48 connected to the output side of the main current and the input side of the main current, and the fulcrum P is contacted with the fixed contact 48 at a predetermined position. A movable contact 50 formed so as to be rotatable about an axis,
An open spring 52 for urging the movable contact 50 in a direction of separating it from the fixed contact 48 and a movable contact 50 are connected to each other via an operating punch 54, and operate according to opening and closing of the contact by the fixed contact 48 and the movable contact 50. An auxiliary contact 56 for outputting a signal for notifying the control device 18 of the open / closed state of the contact,
An electromagnet 58 that rotates the movable contact 50 by contacting the fixed contact 48 by attracting the armature 50a attached to the movable contact 50, and a holding coil 60 that generates a magnetic flux that causes the electromagnet 58 to attract the armature 50a. , A holding current control circuit 62 for supplying a predetermined holding current to the holding coil 60 and stopping the output of the holding current when an opening command is input from the control device 18, and is connected in series to the main current input side. The trip coil 64 that causes the electromagnet 58 to generate a magnetic flux in a direction opposite to the magnetic flux generated by the holding coil 60 according to the current is connected in parallel with the trip coil 64, has a predetermined inductance, and has a main current. An induction shunt 66 is provided to increase the rate at which the current is shunted to the trip coil 64 in the case of a sudden change.

In the circuit breaker 36 thus constructed, a predetermined current is passed through the holding coil 60 and the armature 5 is attached to the electromagnet 58.
By attracting 0a, the fixed contact 48 and the movable contact 50 are closed, the main current becomes larger than a predetermined value, and a current larger than a predetermined value flows through the trip coil 64.
By canceling the magnetic flux by the holding coil 60,
The attraction force of the electromagnet 58 is canceled, and the armature 50a is pulled by the opening spring 52 to open the contact. When the fluctuation of the main current is relatively gentle, the trip coil 64 and the induction shunt 66 have currents inversely proportional to their respective resistance components, so that the above-mentioned contacts are opened according to the main current. Although the operation is performed, when the main current changes abruptly, the ratio of the main current shunted to the trip coil 64 increases due to the influence of the inductance component of the induction shunt 66. Even if there is, the above-mentioned operation of opening the contact is activated.

When the contact is opened, the movable contact 50
By pressing the operating punch 54 to operate the auxiliary contact 56, an opening notification signal for notifying the opening state is output.
Further, an opening command is input to the holding current control circuit 62 from the control device 18, and the holding current control circuit 62 causes the holding coil 60 to
When the supply of the electric current to the electromagnet 58 is stopped, the holding force of the electromagnet 58 disappears regardless of the state of the trip coil 64, so that the contact is opened.

In the DC substation 2 configured as described above, the extra-high voltage AC power received by the power receiving circuit 8 is converted into predetermined DC power by the transformer circuit 10,
It is supplied to the DC bus DB via the supply line SC of the feeder circuit 14, and further, is supplied from the DC bus DB to each feeder L via the DC line DC.

At this time, the control device 18 controls each supply line S
The direction of the current and its current value are detected through C and each current transformer 38 connected to the DC line DC, and the circuit breaker 3
The open / closed state of the circuit breaker 36 is detected through the auxiliary contact 56 of No. 6, the abnormality determination is performed based on the detection result, and if it is determined that there is an abnormality, an open command is output to the predetermined circuit breaker 36 to cause an accident. Protect each equipment in the DC substation 2 by cutting off the current.

Here, the abnormality detection processing executed in the control device 18, that is, the ground fault detection processing, the backflow detection processing, and the unblocking detection processing will be described in detail. Note that the control device 18 executes an initialization process when the power is turned on, initializes the values of flags Fb, Fj, and Fg, which will be described later, to 0, and then periodically (every 1 msec cycle in this embodiment). ) Executes each abnormality detection process.

Each supply line SC and DC line DC
The current transformer 38 provided at is configured so that the current flowing into the DC bus DB is + (plus) and the current flowing out of the DC bus DB is-(minus), and the current value is read. First, a ground fault detection process for detecting a case where the DC bus DB is grounded in a state of having a predetermined resistance value (so-called ground fault) will be described with reference to the flowchart shown in FIG.

As shown in FIG. 4, when this process is executed, first, in S110, the current value I is read from all the current transformers 38 provided in each supply line SC and DC line DC, and the process is continued. In S120, all the read current values are added to calculate a total current value Ib, and the process proceeds to S130.

In S130, it is determined whether or not the total current value Ib is a predetermined current value (1000 A in this embodiment) or more. If the total current value Ib is less than 1000 A, S1
If the total current value Ib is 1000 A or more and the flag Fb is set to 0 and the process is terminated, the process proceeds to S1.
Move to 50.

In S150, it is determined whether or not the total current value Ib is a predetermined current value (5000 A in this embodiment) or more, and if the total current value Ib is 5000 A or more, S16
The set time Tb is changed to 0 for a predetermined time (1 in this embodiment).
0 msec), the process proceeds to S180, and the total current value I
If b is less than 5000A, the process proceeds to S170 and the ratio of the predetermined current 5000A to the total current value Ib is set to the predetermined time 10
After setting a value obtained by adding msec as the set time Tb, S1 is set.
Proceed to 80.

In S180, it is determined whether or not the flag Fb is set to 1. If the flag Fb is set to 1, the process directly proceeds to S200 and the flag Fb is set to 1.
If not set, the process proceeds to S190, the flag Fb is set to 1, the timer tb is started, and then the process proceeds to S200.

In S200, it is determined whether or not the value of the timer tb is equal to or longer than the set time Tb. If the value of the timer tb is smaller than the set time Tb, this process is terminated as it is, and the value of the timer tb is set to the set time. If Tb or more, the process proceeds to S210. In S210, after outputting the opening command to all the circuit breakers 36, the flag Fb is set to 0, the timer Tb is stopped, and this processing is ended.

As described above, in the ground fault detection process, when the total current value Ib of the currents flowing into and out of the DC bus DB is a predetermined current (1000 A) or more and the current continues to flow for a predetermined time or more, it is abnormal. It is determined that there is, and moreover, the larger the current, the shorter the abnormality is determined. That is, when a current corresponding to the shaded area in FIG. 5 flows, it is determined to be abnormal, and when the total current value Ib is smaller than 1000 A or the duration thereof does not reach 10 msec, the abnormality occurs. If the total current value Ib is 1000 A, it will be 50
If the current continues to flow for msec or more, it is determined to be abnormal, and the duration required until it is determined to be abnormal is inversely proportional to the increase in the total current value Ib. At 5000A or more, the current is continuously maintained for 10 msec or more. When is flowing, it is determined to be abnormal.

Usually, the sum of current values flowing from the supply line SC to the DC bus DB and the DC line DC from the DC bus DB.
The sum of the current values flowing out via
The total current value Ib calculated in this process must be approximately 0 A. However, in the case of a ground fault, the current values flowing in and out are not the same, so the total current value Ib becomes 0 A. Therefore, the ground fault can be detected by this method.

Next, FIG. 6 shows a backflow detection process for detecting the case where a current more than a predetermined current flows in the reverse direction in the line (the supply line SC in this embodiment) in which the current should flow in one direction.
A description will be given according to the flowchart shown in FIG. It should be noted that this process is executed for each supply line SC.

As shown in FIG. 6, when this process is executed, first, at step 310, the current value Ig from the current transformer 38 provided in the supply line SC to be processed is set.
Is read and the process proceeds to S320. In S320, the read current value Ig is a predetermined current value (-1000 in this embodiment).
A) Whether or not the absolute value is 100 or less in the direction outflowing from the DC bus DB (reverse flow direction of the supply line SC).
It is determined whether or not a current of 0 A or more has flowed, and if the current value Ig is greater than -1000 A, that is, the current has flowed in the direction (forward direction) flowing into the DC bus DB, or even if it has flowed in the reverse direction, it must be less than 1000 A. For example, the process proceeds to S330, the flag Fg is set to 0, the present process is terminated, and the current value Ig
Is −1000 A or less, that is, 100 in the reverse flow direction.
If a current of 0 A or more has flowed, the process proceeds to S340.

In S340, it is determined whether or not the current value Ig is less than or equal to a predetermined current value (-5000A in this embodiment), that is, the absolute value is 5000A in the reverse flow direction of the supply line SC.
It is determined whether the above current flows, and the current value Ig is -5.
If the current is 000 A or less, that is, if a current of 5000 A or more flows in the reverse flow direction, the process proceeds to S350, sets the set time Tg to a predetermined time (10 msec in this embodiment), and then proceeds to S370, where the current value Ig Is greater than -5000A, that is, if a current whose absolute value is 1000A or more and less than 5000A flows in the reverse flow direction, S
After shifting to 360, the ratio of the absolute value 5000A of the predetermined current to the absolute value | Ig | of the read current value multiplied by the predetermined time 10 msec is set as the set time Tg, and then the process proceeds to S370.

In S370, it is determined whether or not the flag Fg is set to 1. If the flag Fg is set to 1, the process directly proceeds to S390 and the flag Fg is set to 1.
If not set, the flow proceeds to S380, sets the flag Fg to 1, starts the timer tg, and then proceeds to S390.

In S390, it is determined whether or not the value of the timer tg is equal to or longer than the set time Tg, and if the value of the timer tg is smaller than the set time Tg, this processing is ended as it is, and the value of the timer tg is set to the set time. If Tg or more, the process proceeds to S400. In S400, after outputting an opening command to all the circuit breakers 36, the flag Fg is set to 0, the timer Tg is stopped, and this processing is ended.

In other words, in the backflow detection process, it is determined that there is an abnormality when a current of a predetermined current (1000 A in the backflow direction) or more flows in the supply line SC for a predetermined time or more, and the magnitude of the current is large. Accordingly, the larger the current is, the shorter time is determined to be the abnormality. The area determined to be abnormal is the same as the case where the total current value Ib is replaced with the current value Ig and the value is made negative in FIG.

Next, the interruption impossible detection processing for detecting the case where the current continues to flow even though the circuit breaker 36 is opened will be described with reference to the flowchart shown in FIG. It should be noted that this processing is executed for each of the lines SC, DC, BC. As shown in FIG. 7, when this process is executed, first, in S410, the auxiliary contact 56 of the circuit breaker 36 provided in the line SC or DC, BC that is the target of the process.
The open / closed state Pj of the circuit breaker 36, which is the output of
At 420, it is determined whether or not the circuit breaker 36 is in the open state, and if it is in the open state, the process proceeds to S430 and the current transformer 38 is opened.
The current value Ij is read via.

In subsequent S440, the absolute value of the read current value | Ij | is a predetermined current (1000 A in this embodiment).
It is determined whether or not it is above, and if it is above a predetermined current, S450
Move to If the absolute value | Ij | of the read current value is smaller than 1000 A in S440, or if it is determined in S420 that the circuit breaker 36 is not in the open state, the process proceeds to S490 and the flag is set. After setting Fj to 0, this processing ends.

In S450, it is determined whether or not the flag Fj is set to 1, and if it is set to 1, the process proceeds to S470 as it is, and if it is not set to S, it is set to S.
460, the flag Fj is set to 1 and the timer t
After starting j, the process proceeds to S470.

In S470, it is judged whether or not a predetermined time (100 msec in this embodiment) has elapsed since the timer tj was started, and if the predetermined time has not elapsed,
If this process is finished and the specified time has passed,
The process proceeds to S480. In S480, the circuit breaker 36 connected to the line SC or DC or BC that is the target of this processing.
After outputting the opening command to all the circuit breakers 36 other than the above, the flag Fj is set to 0, the timer Tj is stopped, and then this processing is ended.

That is, although the circuit breaker 36 is actuated for some reason and the opening of the circuit breaker 36 is detected by the auxiliary contact 56, a current of a predetermined value (1000 A) or more for a predetermined time (100 msec) or more. If it continues to flow, circuit breaker 3
No. 6 judges that it is impossible to cut off.

The cause of such inability to be interrupted is, for example, that the arc generated between the contacts does not extinguish when the circuit breaker 36 is opened. In order to detect this, the conventional device is equipped with an arc detector 92. However, this processing can realize a function equivalent to this.

As described above, in the DC / DC substation 2, the current transformer 38 and the circuit breaker 36 are connected to each supply line SC and DC line DC, and the circuit breaker 36 is further connected.
Is provided with an auxiliary contact 56, and the control device 18
Based on the current value detected by the current transformer 38 and the auxiliary contact 56, the inflow / outflow direction thereof, and the open / close state of the circuit breaker 36, various abnormality detection processes such as a ground fault detection process, a backflow detection process, and an unbreakable detection process are performed. Is going.

That is, without using the reverse current relay 86 and the arc detector 92 provided in the conventional device, the reverse current detection process and the uninterruptible detection process are performed to reverse the current flow in the supply line SC and the respective lines SC and DC. , BC, it is possible to detect an abnormality such as the interruption of the circuit breaker 36.

Further, since the current values on the lines SC, DC, BC are collected and controlled by the control device 18, a processing program for detecting the maximum value of the current on each line SC, DC, BC, and If a memory that stores the maximum value detected by the processing program and a display device that can display the maximum value stored in the memory are prepared if necessary, the DC current with residual pointer that was provided in the conventional device The maximum value of the current can be recorded without the need for the meter 90. Moreover, since the data can be read and the values can be initialized without going to the site where the DC ammeter 90 with residual pointer is attached unlike the conventional device, the inspection can be easily performed.

As described above, according to the present embodiment, the reverse current relay 86, the arc detector 92, the DC ammeter 90 with the residual pointer, etc. can be omitted as compared with the conventional apparatus. At the same time, the power consumed by these devices is reduced, so that the power consumption of the entire facility can be reduced.

Further, the current transformer 38 for detecting the current value and the current direction of each line SC, DC, BC can be attached at an arbitrary position, unlike the arc detector 92 of the conventional device, etc. It can be arranged at a relatively safe position, and it does not require precision in mounting and adjustment as compared with the arc detector 92, and since it hardly changes over time, mounting and maintenance are easy. At the same time, a stable function can be realized.

Further, according to this embodiment, each line SC, D
Since the current values in C and BC are collected by the control device 18 and are collectively controlled, the control device 18 can easily perform calculation and determination of these current values, and as a result, in the present embodiment. According to this, it is possible to detect the ground fault of the DC bus DB, which cannot be detected by the conventional device.

That is, when a fault current of the same level as the load current flows due to the ground fault of the DC bus DB, the conventional apparatus detects the magnitude of the current for each line.
Although it is not possible to distinguish between the fault current and the load current, according to the present embodiment, each line SC, DC in the ground fault detection process.
By calculating the sum of the current values that normally flow into and out of the DC bus DB via the current path, if there is a current flow in or out of a path other than the normal path, the total current value Ib will deviate significantly from 0A. It is possible to detect an accident.

Furthermore, since the control device 18 monitors the current flowing through each line, monitors the contacts of the circuit breaker 36, and controls the opening and closing of the circuit breaker 36, a program for confirming the operation of each part of the equipment based on these is performed. By preparing, it is possible to automatically inspect equipment and the like, and labor saving in maintenance can be achieved.

Next, the feeder section 4 and the feeder tie post 6 will be described. As shown in FIG. 8, the feeder section 4 comprises a feeder circuit 68 and a control device 70. The feeder circuit 68 is the feeder circuit 14 of the DC substation 2 in which the supply line SC is omitted. The control device 70 has exactly the same configuration and the current value and the direction of the current of each DC circuit DC and the backup circuit BC via the current transformer 38 and the circuit breaker 36.
The open / closed state of the circuit breaker 36 is detected through the auxiliary contact 56 of the
Outputs a release command to the. The control device 70
In, the ground fault detection process and the unblocking detection process for the DC line DC and the backup line BC are executed.

Next, as shown in FIG. 9, the feeder tie post 6 comprises a feeder circuit 72 and a controller 74, and the feeder circuit 72 connects the feeder circuit 72 from each feeder L. It has two disconnecting switches 34 to be disconnected and a circuit breaker 36a provided between the two disconnecting switches 34. Further, between the circuit breaker 36a and each disconnecting device 34, the DC substation 2 and Similar to the DC line SC of the distribution section 4, a current transformer 38 that detects the current value and the direction of the current, a failure selection device 40a connected through the current transformer 42, and an abnormality through the feeder L A lightning arrester 46 for preventing a voltage from entering the feeding tie post 6 is connected to each.

The fault selecting device 40a is operated by ΔI-ΔE.
What is called a shape is used, not only the change in current,
Accidents such as short circuits and ground faults are also detected by detecting changes in voltage. Therefore, the DC transformer 76 is connected to one side across the circuit breaker 36a, and the output thereof is input to each failure selection device 40a. Further, in the feeder tie post 6, when the feeder L is short-circuited, a fault current flows in either direction depending on the location of the short-circuit, and the circuit breaker 36
Since only one a is provided, the circuit breaker 36a is
Instead of the unidirectional type used in the DC substation 2 and the feeder section 4, a bidirectional type capable of interrupting a fault current in any direction is used.

Then, in the controller 74, the feeder section 4
Similarly, the ground fault detection process and the unblockable detection process are executed. The feeder tie post 6 corresponds to a DC bus CB between the breaker 36a and the current transformer 42 of one line, and two DC lines DC are connected to this DC bus CB, and one DC line is connected. It can be considered that the circuit breaker 36a is omitted in the line DC. Further, instead of the bidirectional circuit breaker 36a, the unidirectional circuit breaker 36 may be arranged so as to block currents in the opposite directions, and the feeder tie post 6 may be configured. DC busbar CB between circuit breakers 36
In this configuration, the DC bus CB is connected to a DC line DC that is substantially similar to the DC substation 2 and the feeder section 4.

In this way, the current transformer 38 for detecting the current is provided in the feeder circuits 68, 72 of the feeder section 4 and the feeder tie posts 6, and the auxiliary contacts are provided in the circuit breakers 36, 36a for control. In the case of the DC substation 2 also in the feeder section 4 and the feeder tie post 6, by configuring the devices 70 and 74 to perform the abnormality detection processing based on the detected values of the current transformer 38 and the auxiliary contact. It is possible to obtain substantially the same effect as.

Next, in the above-mentioned embodiment, the feeding equipment for supplying the DC power to the pair of up / down lines has been described. However, the current is supplied to the plurality of pairs of up / down lines. The electrical equipment will be described. FIG. 10 is a schematic configuration diagram showing the configuration of the DC substation 2a in this case.

As shown in FIG. 10, the DC substation 2a is
It has feeder circuits 14a and 14b for supplying electric power to each pair of feeder wires L1 and L2, and control devices 18a and 18b provided for the feeder circuits 14a and 14b, respectively. DC bus D constituting circuits 14a and 14b
B and DB are connected to each other via a disconnector 78.

The feeder circuits 14a and 14b have exactly the same configuration as the feeder circuit 14 of the DC substation 2 described above, except that the DC buses DB and DB are connected to each other via a disconnector 78. Therefore, the description is omitted here.
Further, each feeding circuit 14a, 14b has a transformer circuit 10,
Although a smoothing circuit (not shown) and the like are also connected, description of these is also omitted.

Further, the disconnector 78 includes the above-mentioned breaker 36.
Similarly to the above, an auxiliary contact (not shown) for detecting the open / closed state of the contact is attached, and the output thereof is each control device 18
a, 18b. Furthermore, each control device 18
a and 18b are connected to each other by a communication line SL, and via this communication line SL, the current value of each line SC, DC, BC in each feeder circuit 14a, 14b and the open / close state of the circuit breaker 36, and Results and the like of the abnormality detection processing are input and output to and from each other. When the disconnector 78 is opened,
Each control device 18a, 18b has a respective feeding circuit 14a,
The above-described various abnormality detection processing is performed only inside 14b.
On the other hand, when the disconnector 78 is closed, the main control device 18a is the other control device 18 during the ground fault detection process.
From b, the detected value such as the current value regarding the feeder circuit 14b and the open / closed state of the circuit breaker is input through the communication line SL, and the process is executed together with the detected value regarding the feeder circuit 14a which is detected by itself. If there is an abnormality as a result of the abnormality determination, an open command is output to the circuit breaker 36 of the feeder circuit 14a, and the controller 18b is notified of the determination result via the communication line SL. An opening command is output to the circuit breakers 36 of 14b to operate each circuit breaker 36.

It should be noted that the backflow detection process and the unblocking detection process are performed even if the disconnector 78 is closed.
The determination result is notified to the other control devices 18a and 18b via the communication line SL, and the circuit breakers 36 of the respective feeding circuits 14a and 14b are connected to each other. It is controlled in conjunction with the states of 14a and 14b.

Therefore, even in a structure such as the DC substation 2a that supplies electric power to the plurality of pairs of feeders L1 and L2, the same effect as that of the above DC substation 2 can be obtained. Although the embodiments have been described in detail above, the present invention is not limited to the above embodiments and can be implemented in various modes without departing from the scope of the present invention.

For example, in the above-described embodiment, when it is determined that the abnormality is detected by the abnormality detection processing, all the circuit breakers 36 are controlled to be opened. However, depending on the content determined to be abnormal, the abnormality is detected. You may make it open only the circuit breaker 36 with which it is closely related. Further, in the supply line SC of the DC substation 2, a disconnector may be used instead of the circuit breaker 36. In this case, when the control device 18 detects an abnormality in the abnormality detection processing, the transformation circuit 10 Alternatively, the AC circuit breaker 20 may be opened.

Next, in the above embodiment, the control devices 18, 7 for the DC substation 2, the feeder section 4, and the feeder tie post 6 are provided.
0 and 74 respectively perform abnormality detection processing only inside the equipment and perform opening / closing control of the circuit breaker 36, but the control devices 18, 70 and 74 of the equipments 2, 4 and 6 adjacent to each other are connected by signal lines. When there is an abnormality as a result of the abnormality detection processing executed by each of the control devices 18, 70, 74 after connection, the abnormality is notified to the control devices 18, 70, 74 of the adjacent equipment via a signal line. However, the circuit breaker 36 may be operated in conjunction with each other.

In the above embodiment, the DC line DC is
Although the circuit breaker 36 and the disconnector 34 are separately connected,
A circuit breaker with a built-in disconnector may be connected to the position where the circuit breaker 36 is connected. Furthermore, in the circuit breaker 36 of the above embodiment, the contacts are opened by cutting off the current flowing through the holding coil 60 in accordance with the opening command, but the current flowing through the trip coil 64 is controlled. The contacts may be opened. Also, as the circuit breaker 36,
Although the one in which the opening / closing operation of the contact is electrically controlled is used, the one in which the opening / closing operation of the contact is mechanically controlled may be used.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a DC substation 2 of this embodiment.

FIG. 2 is an explanatory diagram showing an outline of feeding equipment in a direct current electrification section of a railway according to the present embodiment.

FIG. 3 is an explanatory diagram showing a configuration of only a part related to an opening / closing operation of a contact of a circuit breaker.

FIG. 4 is a flowchart of a ground fault detection process executed by the control device 18.

FIG. 5 is an explanatory diagram showing a region determined to be abnormal by the ground fault detection process.

FIG. 6 is a flowchart of a backflow detection process executed by the control device 18.

FIG. 7 is a flowchart of a disconnection impossible detection process executed by the control device 18.

FIG. 8 is a schematic configuration diagram of a feeding station 4.

FIG. 9 is a schematic configuration diagram of a feeding tie post 6.

FIG. 10 is a schematic configuration diagram of a DC substation 2 having a plurality of feeder circuits 14a and 14b.

FIG. 11 is a schematic configuration diagram of a feeder circuit in a conventional DC substation.

[Explanation of symbols]

2, 2a ... DC substation 4 ... Feeding station 6 ...
Feeding tie post 8 ... Power receiving circuit 10 ... Transformation circuit 12 ... High voltage distribution circuit 14, 14a, 14b, 68, 72 ... Feeding circuit 16
... Smoothing circuit 18, 18a, 18b, 70, 74 ... Control device 20
… AC breakers 22, 34, 44, 78… Disconnectors 24… Transformers
26 ... Silicon rectifier 28, 38, 42 ... Current transformer 36, 36a ... Circuit breaker 40, 40a ... Failure selection device 48 ... Fixed contact 5
0 ... Movable contact 52 ... Opening spring 54 ... Operating punch 56 ... Auxiliary contact
58 ... Electromagnet 60 ... Holding coil 62 ... Holding current control circuit 64
... Tripping coil 66 ... Induction shunt 76 ... DC transformer DB ... DC bus CB ... Common bus SC ... Supply circuit DC ... DC circuit BC ... Preliminary circuit

Claims (4)

[Claims] 1. A plurality of DC lines respectively connected to a plurality of feeder lines provided for supplying DC power used for operating a train, and a DC bus bar connecting one end of each of the plurality of DC lines. When each DC line has a contact for cutting off the current flowing in the DC line and a current more than a predetermined amount flows in the DC line, or when an opening command is input from the outside A protection device for feeding equipment, comprising: a disconnecting means for opening the contact, and a current detecting means provided for each of the DC lines to detect a current value and a current direction flowing through the DC line; An operation unit that outputs an opening command to a predetermined breaking unit when determining an abnormality in the current flowing in and out of the DC bus based on the current value and the current direction detected by the detection unit and determining that there is an abnormality. Is characterized by the provision of A protective device for feeding equipment. 2. The protective device for feeding equipment according to claim 1, wherein the computing means outputs the total current value flowing into the DC bus and the DC bus flowing out from the DC bus based on the detection result of the current detecting means. Calculating means for calculating a difference from the total current value, and determining whether or not the absolute value of the calculated value calculated by the calculating means is a predetermined value or more, and when the calculated value is a predetermined value or more,
A protective device for feeding equipment, comprising: a ground fault judging means for judging an abnormality. 3. The feeder protection apparatus according to claim 1 or 2, wherein a contact monitoring means for monitoring the operating state of the contact is provided for each of the breaking means, and the computing means further comprises: On the basis of the detection result of the contact monitoring means, an open judging means for judging whether or not each of the breaking means is in an open state, and the current detecting means for the DC line having the breaking means judged to be in the open state. It is determined that the current value detected by the above is judged to be a predetermined value or more, and if the current value is a predetermined value or more, it is judged that there is an abnormality. Protection equipment for electrical equipment. 4. The feeder protection device according to claim 1, wherein at least one supply line for supplying DC power to the DC bus is provided in the supply line, When a current more than a predetermined value flows in the supply line or when an opening command is input from the outside, a disconnecting means for opening the connection with the DC bus, and a current value of the current flowing through the supply line and Current detecting means for detecting an inflow / outflow direction, and the arithmetic means determines whether or not the current detected by the current detecting means connected to the supply line is flowing in the power supply direction. A protective device for feeding equipment, comprising a backflow determining means for determining that there is an abnormality when the power is flowing in a direction opposite to the power supply direction.