JP2011020548A - ALTERNATING CURRENT DeltaI TYPE FAULT SELECTION DEVICE - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a fault at a current value close to an original power supply system without being affected by SVC. <P>SOLUTION: The alternating current ΔI type fault section device includes: an input conversion means 31 for converting current flowing on the power supply system of a down electric train line and an up electric train line, and current flowing on a switching section to an optional current value, respectively; a sampling hold means 32 for sampling-storing converted individual analog current values at a predetermined cycle; an A/D conversion means 33 for converting the sampled individual analog current values to a digital current value, respectively; a harmonic wave detection means 34 for extracting a harmonic wave component from a digital current value corresponding to the current flowing on the switching section; and a harmonic wave component synthetic processing means 35 for calculating a load equivalent current by multiplying the extracted harmonic wave component by a synthesis ratio determined according to a system state, to synthesize into a digital current value corresponding to the current flowing on the power supply system. The alternating current ΔI type fault section device executes operation when the amount of current variation ΔI calculated from the obtained load equivalent current exceeds a predetermined value. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an AC ΔI type fault selection device for an AC feeder circuit used in a Shinkansen railway.

  In the AC feeder circuit used for the Shinkansen railway, in the event of a ground fault in the train line system including the feeder circuit system, in order to protect the equipment of the train and feeder substation, Separately, an AC ΔI type failure selection device is installed as a protection system that reliably detects and shuts down accident failures.

  This AC ΔI type fault selection device monitors the current change amount ΔI of the AC feeder circuit, detects an accident when the current change amount ΔI exceeds a predetermined value, and executes operations to protect various system devices. .

FIG. 4 is a system configuration diagram of a conventional AC feeding circuit provided with an AC ΔI type fault selection device.
In the figure, 1A is a single-phase AC power source obtained at a feeder substation, and 1B is a single-phase AC power source that is a different power source obtained at the same feeder substation (usually from the same substation 2 is a switch for the down train line installed in the power supply system 3 for the down train line, 4 is a power supply system for the up train line 5 Switch for upstream train line installed in, 6 and 7 for auxiliary current transformer for downward train line, auxiliary current transformer for upstream train line, 8 and 9 for monitoring the amount of current flowing through power supply systems 3 and 5 The AC ΔI type fault selection device for down train lines and the AC ΔI type fault selection device for up train lines.

  Also, 10 is a different power source switching section, 11 and 12 are switching circuit breakers that are switched when the train 13 passes through the different power source switching section 10, 14 and 15 are switching section side auxiliary current transformers, and 16 is a switching section. An auxiliary current transformer 17 sets the current of the side auxiliary current transformer 14 to a current transformation ratio 1/4, and 17 denotes an auxiliary current transformer which sets the current of the switching section side auxiliary current transformer 15 to a current transformation ratio 1/3.

  Furthermore, a reactive power compensator (Static Var Compensator: hereinafter referred to as SVC) 20 is connected to the end of the AC feeder circuit for the Shinkansen railway (Patent Document 1). Here, the reason for providing the SVC 20 is to compensate for the voltage drop of the AC feeder circuit by compensating for the delayed reactive power.

  By the way, in the Shinkansen railway, there is a problem that the current increases due to several factors other than the ground fault and the like, and the AC ΔI type fault selection devices 8 and 9 are operated unnecessarily.

  Therefore, AC feeding circuits used for the Shinkansen railway are provided with means for measuring the contents of the second and third harmonic currents contained in the fundamental current and preventing unnecessary operations.

  One unnecessary operation preventing means is that when the train 13 of the Shinkansen railway passes through the different power source switching section 10, a large no-load excitation inrush current flows through the in-vehicle transformer. This no-load magnetizing inrush current has an asymmetrical top and bottom waveform and contains a lot of second harmonic current. Therefore, when the content of the second harmonic current is equal to or greater than a certain value, AC ΔI type fault selection The operation of the device 9 (8) is suppressed.

  As another unnecessary operation prevention means, when the train 13 of the Shinkansen railway enters the different power supply switching section 10, the switching breaker 11 is cut off and the switching breaker 12 is turned on, so-called different power supply switching. A sudden load current flows. At this time, when the load current by the train 13 is flowing, since the third harmonic current is included in the feeding current, it is determined that the fundamental current is small from the content of the third harmonic current, and the alternating current The operation of the ΔI type failure selection device 9 (8) is suppressed.

  Therefore, the unnecessary operation preventing means is based on the premise that when the train 13 passes through the switching section 10, a large no-load excitation inrush current flows, and the amount of change in the current flowing in the power supply system 5 for the upstream train line increases. Unnecessary operation of the AC ΔI type failure selection device 9 is prevented.

  However, as described above, when the SVC 20 is installed on the terminal side of the AC feeding circuit used for the Shinkansen railway, the second and third harmonic currents Ifn included in the feeding current as the fundamental current are increased from the SVC 20 side. As a result of the diversion to the electric power supply system 5 side for the train line, only about a half harmonic current (1/2) Ifn of the actual harmonic current Ifn flows through the auxiliary current transformer 7 for the upward train line. . Here, the reason why only the half harmonic current (1/2) Ifn flows through the auxiliary current transformer for the upstream train line 7 is that between the auxiliary current transformer for the downward train line 6 to the SVC 20 and the auxiliary current for the upward train line. This is because the impedance between the current transformer 7 and the SVC 20 is an equivalent value.

  As a result, the content rate of the second and third harmonic currents is reduced, and for example, the operation of the AC ΔI type fault selection device 9 for the up-bound train line is not suppressed and may malfunction.

  Therefore, the current of the auxiliary current transformer 15 for the switching section is reduced to 1/3 by the auxiliary current transformer 17 and is subtracted from the current of the auxiliary current transformer 7 for the upstream train line. Apparently, the current input to the selection device 9 is reduced to reduce the amount of change in the current to prevent malfunction.

  On the other hand, when the train 13 passes through the switching section 10, almost no fundamental current flows through the auxiliary current transformer 6 for the descending train line, but the harmonic current (1/2 of the harmonic current Ifn is 1/2). ) Ifn is flowing by the diversion by the SVC 20. If an accident occurs at the same time, there is a possibility of malfunction due to the AC ∆I type fault selection device 8 for the descending train line.

  For this reason, the current of the auxiliary current transformer 14 for the switching section is reduced to ¼ by the auxiliary current transformer 16 and added to the current of the auxiliary current transformer 6 for the descending train line, whereby the down line AC ΔI type fault selection device. The current input to 8 is apparently increased to reduce the harmonic content to prevent malfunction.

JP 2003-2088 A

  By the way, according to the technique for preventing the unnecessary operation of the AC ΔI type fault selection device as described above, the following problems have been pointed out.

(1) When the train 13 passes through the switching section 10, the 1/3 subtraction from the current of the auxiliary current transformer 7 for the upward train line disappears, and the state is substantially increased by 1/3. Therefore, 1/3 of the current input to the AC ΔI type fault selection device 9 for the upward train line is added, the current change amount becomes large, and there is a possibility of malfunction.

(2) When the train 13 enters the switching section 10, the auxiliary current transformer 17 subtracts 1/3, so that it differs from the actual current value flowing through the power supply system 5 for the upstream train line. And detection of grid faults may be delayed.

(3) The technique for preventing unnecessary operation described above always subtracts or adds a constant current to the current of the auxiliary current transformer 7 for the upward train line and the auxiliary current transformer 6 for the downward train line. When the feeder system is changed in accordance with the switching operation of the switches 2 and 4, the current input to the AC ΔI type fault selection device 9 for the upward train line and the AC ΔI type fault selection device 8 for the downward train line is normally There is a problem in that there is a possibility of unnecessary operation due to significant addition or subtraction compared to the case.

  The present invention has been made in view of the above circumstances, and is influenced by the SVC installed at the end of the AC feeder circuit by synthesizing an appropriate harmonic component according to the system state into the current flowing through the power supply system. An object of the present invention is to provide an AC ΔI type fault selection device that reliably detects an accident with a current value close to that of the original power supply system.

In order to solve the above problems, the present invention is an AC ΔI type fault selection device that is connected to an AC feeder circuit having a reactive power compensator on the terminal side and detects and protects various system faults.
When the train passes through the different power supply switching section, the first and second currents flowing in the power supply system for the descending train line and the power supply system for the upstream train line and the third current flowing in the different power supply switching section are arbitrary. Current conversion means for converting the first to third analog current value data, and sampling hold for sampling and storing the first to third analog current value data converted by the current conversion output means at a predetermined cycle Means, A / D conversion means for converting the first to third analog current value data sampled and stored into first to third digital current value data, respectively, and the A / D conversion means converted by the A / D conversion means. Harmonic detection means for extracting digital harmonic data from the digital current value data of 3 and the system state for the digital harmonic data extracted by this harmonic detection means Depending multiplying determined synthesis ratios, said first and synthesized into a second digital current value data, and a harmonic component synthesizing processing means for calculating a load equivalent current,
This is an AC ΔI type fault selection device that obtains a current change amount ΔI from the load-corresponding current obtained by the harmonic component synthesizing means and performs a protection operation when the obtained current change amount ΔI exceeds a predetermined value.

  According to the present invention, an appropriate harmonic component is obtained by changing the synthesis ratio in accordance with the system state, and is synthesized with the current flowing in the power supply system, thereby affecting the SVC installed at the end of the AC feeder circuit. Instead, it is possible to provide an AC ΔI type fault selection device that detects a system fault with a current value close to that of the original power supply system.

1 is a system configuration diagram of an AC feeder circuit incorporating an AC ΔI type fault selection device according to the present invention. The block block diagram which shows one Embodiment of the alternating current (DELTA) I type | mold fault selection apparatus which concerns on this invention. The data array example figure of the synthetic | combination ratio table provided in the memory | storage device. The system block diagram of the conventional AC feeder circuit containing an alternating current (DELTA) I type | mold fault selection apparatus.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a system configuration diagram of an AC feeder circuit provided with an AC ΔI type fault selection device according to the present invention. In this figure, the same parts as those in FIG.

This AC feeder circuit is similar to FIG. 4 described above, and is provided on the down train line power supply system 3 side on the down train line switch 2, down train line auxiliary current transformer 6, and up train line power supply system. On the side 5, an up train line switch 4 and an up line auxiliary current transformer 7 are also installed. In addition, the own post upper and lower tie switches 21 are installed between the power supply systems 3 and 5. These switches 2 and 21, the auxiliary current transformers 6 and 7, and the different power source switching section 10 are installed. A central protective relay device 23 is connected to each output side of the auxiliary current transformer 22.

  The aggregated protective relay device 23 accommodates an AC ΔI type fault selection device according to the present invention and other protective relay devices such as a distance relay device.

  The AC ΔI type fault selection device takes in the currents Ia, Ib, In acquired from the auxiliary current transformers 6, 7, 22 and the open / closed states (system state) of the respective switches 2, 4, 21, system faults, etc. The operation to protect AC feeder circuits, trains, and substation equipment in the event of an outbreak.

  Further, the adjacent post upper and lower tie switches 24 and the SVC 20 are installed on the adjacent post which is the end of the AC feeder circuit. The adjacent post upper and lower tie switches 24 match the power supplied from the power supply systems 3 and 5 to the descending train line and the ascending train line.

  FIG. 2 is a block configuration diagram showing an embodiment of the AC ΔI type failure selection device 30 housed in the intensive protection relay device 23.

  The AC ΔI type fault selection device 30 is an input conversion means (converter) for converting a plurality of currents 1a, Ib, In acquired by the auxiliary current transformers 6, 7, 22 into arbitrary analog current values (small current values). Current conversion means) 31, sampling hold means 32 for sampling, quantizing and storing each analog current value data at a predetermined period, and each analog current value data sampled and stored as digital value data Ia ′, Ib ′, A / D conversion means 33 for converting to In ′, harmonic detection means 34 for extracting the harmonic digital data Ifn ′ from the digital value data In ′ flowing in the different power supply switching section 10, harmonic component combining processing means 35, , ΔI (current change amount) calculating means 36 is provided.

  The harmonic component synthesis processing means 35 is constituted by a CPU, and functionally, the digital value data Ia ′ and Ib ′ converted by the A / D conversion means 33 and the harmonics extracted by the harmonic detection means 34. From the open / close states CB-a, CB-b, and DS-c of the data storage means 35A that receives the digital data Ifn 'and stores it in the measured data storage unit 37a provided in the storage device 37, and the switches 2, 4, and 21. A system state determination unit 35B for determining a system state, and in accordance with the system state determined by the system state determination unit 35B, a combination process is executed according to a predetermined combination ratio and a predetermined arithmetic expression, and the load equivalent current ΔIa of the train , ΔIb are calculated, and are composed of the synthesis operation processing means 35C that stores the measured data storage unit 37a.

  The ΔI (current change amount) calculating means 36 is composed of a CPU together with the harmonic component combining processing means 35, and based on the load equivalent currents ΔIa and ΔIb calculated by the combining calculation processing means 35C, at the time of a system fault. A current change amount ΔI flowing through the power supply systems 3 and 5 is obtained, a system fault is detected, and a substation or train equipment including an AC feeder circuit is protected.

  The storage device 37 is provided with a composition ratio table 37b in addition to at least the above-described actual measurement data storage unit 37a.

  FIG. 3 is a diagram showing a data arrangement example of the synthesis ratio table 37b.

  That is, in the synthesis ratio table 37b, the user opens or closes (opens) the switches 2, 4, 21 for each system state 1.2,... Through the harmonic synthesis ratio setting means 38 such as a keyboard or a mouse in advance. ) The states CB-a, CB-b, and DS-c are set, and the composite ratios for the load equivalent currents ΔIa and ΔIb at that time are set.

  Next, the operation of the AC ΔI type fault selection device 30 configured as described above will be described.

  First, each of the auxiliary current transformers 6, 7, and 22 transforms the current flowing through the power supply system 3 for the down train line, the power supply system 5 for the up train line, and the different power source switching section 10 at a predetermined current ratio. The currents Ia, Ib, and In are taken out and introduced into the input conversion means 31. The input conversion means 31 converts the currents 1a, Ib, and In acquired by the auxiliary current transformers 6, 7, and 22 into arbitrary analog current values (small current values), respectively.

  Normally, each auxiliary current transformer 6, 7, 22 can be converted into an arbitrary analog current value (small current value). In this case, the substantial structure of the input conversion means 31 is the auxiliary current transformers 6, 7, and 22.

  However, since the outputs of the auxiliary current transformers 6, 7, and 22 can be used for other protective relay devices other than the AC ΔI type fault selection device 30, each auxiliary current transformer 6, 7, 22 is used. It is necessary to add a current-transforming element for converting the currents 1a, Ib, and In acquired in step 1 into an arbitrary analog current value that can be used by the AC ΔI type fault selection device 30. According to this example, the input conversion means 31 includes a current transformer element newly added to each auxiliary current transformer 6, 7, 22.

  As described above, the input conversion means 31 converts each analog current value data corresponding to each of the currents 1a, Ib, In and outputs it. At this time, the sampling and holding means 32 outputs the respective analog current value data with a predetermined cycle. Arbitrary analog current value data is sampled, quantized, and stored in an appropriate free space in the storage device 37.

  Here, the A / D conversion means 33 converts each analog current value data stored in the sampling and holding means 32 into digital value data Ia ′, Ib ′, In ′, respectively, and then the power supply system 3 for the descending train line. The digital value data Ia ′ and Ib ′ relating to the feeding current flowing in the power supply system 5 for the upstream train line is sent to the harmonic component synthesis processing means 35.

  When receiving the digital value data Ia ′ and Ib ′ from the A / D conversion unit 33, the data storage unit 35 </ b> A in the harmonic component synthesis processing unit 35 sequentially stores the digital value data Ia ′ and Ib ′ in the measured data storage unit 37 a of the storage device 37.

  On the other hand, with respect to the digital value data In ′ corresponding to the current flowing in the different power supply switching section 10 digitally converted by the A / D conversion means 33, a harmonic component is extracted by the harmonic detection means 34. That is, the harmonic detection means 34 extracts harmonics from the digital value data In ′ flowing in the different power supply switching section 10, and various harmonic extraction techniques are used. For example, the content rate of the second and third harmonic currents contained in the digital value data In ′ is measured and extracted, or the harmonic digital filter for detecting the second and third harmonic currents from the digital value data In ′, etc. Is used to extract the second and third harmonic components.

The harmonic detection unit 34 sends the extracted digital harmonic component data Ifn ′ to the harmonic component synthesis processing unit 35. The data storage unit 35A of the harmonic component synthesis processing unit 35 receives the received digital harmonic component data Ifn. 'Is stored in the actual measurement data storage unit 37a of the storage device 37. At this time, it is stored in association with the already stored digital value data Ia' and Ib '.

  After storing the digital harmonic component data Ifn ′, the harmonic component synthesis processing unit 35 executes the system state determination unit 35B.

  The system state determination unit 35B takes in the open / closed (closed) states CB-a, CB-b, and DS-c of the respective switches 2, 4, and 21, and the user or the like previously generates a harmonic synthesis ratio such as a keyboard or a mouse. Through the setting means 38, the combination ratio table 37b shown in FIG. 3 set in the storage device 37 is referred to, and any system is selected from the open / close states CB-a, CB-b, DS-c of the respective switches 2, 4, 21. Determine if it is in a state.

  Incidentally, CB-a and CB-b which are the outputs of the down train line switch 2 and the up train line switch 4 are turned on (closed), and the DS-c which is the output of the own post vertical tie switch 21 is When in the open state, it is determined from FIG. 3 that the system state is 1, and the combination ratio with respect to ΔIa = 0.5 and the combination ratio with respect to ΔIb = 1.5 are specified.

  The reason why the combination ratios = (0.5) and (1.5) when the open / close states CB-a, CB-b, and DS-c of the respective switches 2, 4, and 21 are in the system state 1 is as follows. The fundamental current component Ib + the harmonic current component Ifn flows through the auxiliary current transformer 22 on the side of the different power supply switching section 10, but the harmonic current component Ifn is shunted between the SVC 20 and the power supply system 5. The auxiliary current transformer 7 has a fundamental current component Ib−a harmonic current component Ifn / 2 (*). As a result, if the combination ratio with respect to ΔIa = 0.5 and the combination ratio with respect to ΔIb = 1.5, the current value input to the AC ΔI type fault selection device 30 is equivalent to that without the SVC 20. That is, the AC ΔI type failure selection device 30 is not affected by the SVC 20 installed at the end of the AC feeder circuit.

  The meaning of (*) described above is a case where the impedance between the auxiliary current transformer 6 for the downward train line 6 to the SVC 20 and the impedance between the auxiliary current transformer 7 for the upward train line 7 to the SVC 20 are made equal.

  Further, in the system state 2 shown in FIG. 3, the CB-a that is the output of the down train line switch 2 and the DS-c that is the output of the own post vertical tie switch 21 are open, and the up line switch When CB-b, which is the output of 4, is in the input state, the composite ratio with respect to ΔIb = 1.0. The basis for this is that the fundamental current component Ib + the harmonic current component Ifn flows through the auxiliary current transformer 22 on the switching section 10 side, and the harmonic current component Ifn flows through the SVC 20. Only the fundamental current Ib flows. As a result, by setting the composite ratio with respect to ΔIb = 1.0 as described above, the current value input to the AC ΔI type fault selection device 30 becomes equivalent to the case where there is no SVC 20. That is, the AC ΔI type failure selection device 30 is not affected by the SVC 20 installed at the end of the AC feeder circuit.

  Therefore, as described above, the combination ratio table 37b includes an alternating current ΔI for each system state determined in advance by the open / closed (closed) states CB-a, CB-b, and DS-c of the switches 2, 4, and 21. The current composition ratio is set so that the shape failure selection device 30 is not affected by the SVC 20 installed at the end of the AC feeder circuit.

  Therefore, the harmonic component combining processing means 35 is connected to the system state determining means 35A from the open / closed (closed) states CB-a, CB-b, DS-c of the respective switches 2, 4, 21, for example, the system state 1 When it is determined, the synthesis calculation processing means 35C is subsequently executed.

  The synthesis calculation processing unit 35C reads the synthesis ratio data from the synthesis ratio table 37b of FIG. 3 based on the determination result of the system state 1, and then is extracted by the harmonic detection unit 34 already stored in the actual measurement data storage unit 37a. By multiplying the harmonic current component Ifn ′ and combining with the digital value data Ia ′ and Ib ′, the calculation by the following equations (1) and (2) is performed to calculate the load equivalent currents ΔIa and ΔIb. And stored in association with the digital value data Ia ′ and Ib ′ of the actual measurement data storage unit 37a.

ΔIa = Ia ′ + Ifn ′ × synthesis ratio = Ia ′ + (− Ifn ′ × 0.5) (1)
ΔIb = Ib ′ + Ifn ′ × composition ratio = Ib ′ + (+ Ifn ′ × 1.5) (2)
In addition, when the combination operation processing unit 35C determines the system state 2, the combination calculation processing unit 35C calculates the load-equivalent current ΔIa based on the following equation (3) according to the combination ratio set in FIG.
ΔIb = Ib ′ + Ifn ′ × combination ratio = Ib ′ + (+ Ifn ′ × 1.0) (3)
The ΔI calculating means 36 obtains a current change amount ΔI flowing in the power supply systems 3 and 5 from the load equivalent currents ΔIa and ΔIb calculated by the composite arithmetic processing means 35C and the fault current at the time of the grid fault, and the obtained current change When the amount ΔI exceeds a predetermined value, a system fault is selected and necessary protective measures are taken.

  Therefore, according to the above embodiment, even if the SVC 20 is installed on the terminal side of the AC feeder circuit of the Shinkansen railway, the switches 2, 4, 21 installed in the power supply systems 3, 5 Since the harmonic current is multiplied by a preset synthesis ratio in accordance with the system state accompanying opening and closing to obtain an appropriate harmonic component, the resultant is combined with the current flowing through the power supply systems 3 and 5, so the SVC 20 Appropriate harmonic components that are not affected by the current can be input to the AC ΔI type fault selection device 9, and unnecessary operations can be surely prevented by the harmonic components, and it is as close as possible to the current of the original power supply system. A highly reliable AC ΔI type fault selection device 30 that detects a system fault with a current value can be realized.

  In the above embodiment, the input conversion means 31 sequentially switches the currents Ia, Ib, and In to convert them into arbitrary small current values. For example, a plurality of input conversion means 31,. , Ib, In may be configured to individually convert to an arbitrary small current value. This also applies to the sampling hold means 32 and the A / D conversion means 33.

  In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  DESCRIPTION OF SYMBOLS 1A, 1B ... Single phase alternating current power supply, 2 ... Switch for down train line, 3 ... Power supply system for down train line, 4 ... Switch for up train line, 5 ... Power supply system for up train line, 6 ... Auxiliary current transformer for down train line, 7 ... Auxiliary current transformer for up train line, 8 ... AC ΔI type fault selection device for down train line, 9 ... AC ΔI type fault selection device for up train line, 10 ... Different power supply Switching section, 11, 12 ... Switching circuit breaker, 13 ... Train, 20 ... SVC, 21 ... Own post top and bottom tie switch, 22 ... Different power source switching section side auxiliary current transformer, 23 ... Centralized protective relay device, 24 ... Adjacent post upper / lower tie switch, 30 ... AC ΔI type failure selection device, 31 ... input conversion means (current conversion means), 32 ... sampling hold means, 33 ... A / D conversion means, 34 ... harmonic detection means, 35 ... Harmonic component synthesis processing means, 35B ... System state determination Stage, 35C ... combining processing unit, 36 ... [Delta] I (current change amount) computing means, 37 ... storage device, 37b ... combination ratio table, 38 ... harmonic synthesis rate setting means.

Claims (5)

In an AC ΔI type fault selection device that is connected to an AC feeder circuit having a reactive power compensator on the terminal side and detects and protects various system faults,
When the train passes through the different power supply switching section, the first and second currents flowing in the power supply system for the descending train line and the power supply system for the upstream train line and the third current flowing in the different power supply switching section are arbitrary. Current converting means for converting the first to third analog current value data;
Sampling hold means for sampling and storing the first to third analog current value data converted by the current conversion output means at a predetermined cycle;
A / D conversion means for converting the sampled first to third analog current value data into first to third digital current value data, respectively.
Harmonic detection means for extracting digital harmonic component data from the third digital current value data converted by the A / D conversion means;
The digital harmonic component data extracted by the harmonic detection means is multiplied by a synthesis ratio determined in accordance with the system state, and synthesized with either the first or second digital current value data or both current value data. And harmonic component synthesis processing means for calculating the load equivalent current,
AC ΔI type fault selection characterized in that a current change amount ΔI is obtained from the load equivalent current obtained by the harmonic component combining processing means, and an operation is executed when the obtained current change amount ΔI exceeds a predetermined value. apparatus. In the AC ΔI type fault selection device according to claim 1,
The current conversion means detects each of the first and second currents flowing in the power supply system for the descending train line and the power supply system for the upward train line and the third current flowing in the different power source switching section. AC ΔI type fault selection device, characterized in that it is constituted by a device. In the AC ΔI type fault selection device according to claim 1,
The digital harmonic data extracted by the harmonic detection means is a no-load exciting inrush current that occurs when the train passes through the different power supply switching section or a sudden change load current that occurs when the train is switched to a different power source. AC ΔI type fault selection device, characterized in that the data is related to the second and third harmonic currents included. In the AC ΔI type fault selection device according to claim 1,
For each system state determined from the open / closed states of a plurality of switches installed in the down train line power supply system and the up train line power supply system for supplying power to the down train line and the up train line in advance, the AC feeder AC ΔI type characterized by comprising a synthesis ratio table for setting a synthesis ratio for multiplying the digital harmonic component data so as not to be affected by the reactive power compensator installed at the end of the circuit Failure selection device. In the AC ΔI type fault selection device according to claim 1 or 4,
The harmonic component combining processing means determines the system state from the open / closed states of a plurality of switches installed in the power supply system for the down train line and the power supply system for the up train line, and according to the determined system state And an AC ΔI type fault selection device provided with system state determination means for selecting a composite ratio.

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