JP2015100219A - Dc feeder protection relay device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC feeder protection relay device capable of improving sensitivity to feeder failure detection.SOLUTION: A DC feeder protection relay device of an embodiment comprises: a current detection unit which acquires a current value of a DC feeder; a current positive component calculation unit which calculates a current positive component; a pulsion ratio calculation unit which calculates a pulsion ratio on the basis of a first current positive component and a second current positive component; a detection signal output unit which outputs a detection signal when the pulsion ratio is determined to be not less than a pulsion ratio comparison value; a current change value calculation unit which calculates a current change value which is the difference between the first current positive component and a third current positive component; a difference calculation unit which calculates a current change difference which is the difference between the current change value and a current change comparison value; an integration value calculation unit which calculates a current change integration value integrated by multiplying the current change difference by a coefficient; a control signal output unit which outputs a control signal when the current change integration value is determined to be not less than a determination value; and a trip command output unit which outputs a trip command when a detection signal and a control signal are acquired.

Description

  Embodiments described herein relate generally to a DC feeder protection relay device.

In the general feeding circuit shown in FIG. 12, the substation SS ₁ and the substation SS ₂ are provided, for example, at intervals of several tens km.

DC power is supplied to the feeder 31 from each of the substations SS ₁ and SS ₂ .

The substation SS ₁ includes an AC power supply 41, a rectifier 42, a current transformer (CT) 43, a feeder circuit breaker 45, a communication breaker device 46, and a DC feeder protection relay device 47.

  AC power supplied from the AC power supply 41 is converted into DC power by the rectifier 42, passes through the feeder circuit breaker 45, and is supplied to one end of the feeder 31.

Similarly substation SS ₂ includes an AC power supply 51 includes a rectifier 52, CT53, feeding circuit breaker 55, contact shut-off device 56 and a DC feeding circuit protective relay device 57.

  AC power supplied from the AC power source 51 is converted into DC power by the rectifier 52, passes through the feeder circuit breaker 55, and is supplied to the other end of the feeder 31.

  The DC power converted by the rectifiers 42 and 52 is also supplied to the rail 32, and the feeder 31 and the rail 32 supply power to the electric vehicle 33.

  The DC feeder protection relay devices 47 and 57 obtain the current value of the feeder line 31 from the CTs 43 and 53, and open the feeder breakers 45 and 55 when a failure or the like occurs in the feeder line 31.

For example, when detecting a failure of the DC feeding circuit protective relay device 47 brat wire 3, to open the substation SS ₁ eaves electric breaker 45. Further, since the contact blocking device 46, 56 which are connected by communication line 34 to each other, a DC feeding circuit protective relay device 47 is in contact shut-off device 56 of the substation SS ₂ through the contact cutoff apparatus 46 of the substation SS ₁ Outputs a shutoff command signal. That is, the feeder circuit breaker 55 is opened by the DC feeder protection relay device 57 or the communication interruption device 56.

JP 2011-53189 A

When the failure occurs in the feeder 31 and the failure point resistance _Rf is 0.45 [Ω], the failure point section length ratio d, the current change value ΔI _{f at} the failure point per predetermined time, change value [Delta] I 1 of the current flowing through the substation SS _1, an example of the relationship between the change value [Delta] I ₂ of the current flowing through the substation SS ₂ per predetermined time is shown in FIG. 13. Further, the failure point section length ratio d when the failure point resistance R _f is 0.7 [Ω], the current change value ΔI _{f at} the failure point per predetermined time, and the current flowing through the substation SS ₁ per predetermined time. FIG. 14 shows an example of the relationship between the change value ΔI ₁ of the current and the change value ΔI _{2 of the} current flowing through the substation SS ₂ per predetermined time.

Here, the failure point section length ratio d is a ratio from the substation SS ₁ to the failure point when the distance from the substation SS ₁ to the substation SS ₂ is 1. For example, when d = 0.5, it indicates that a failure occurs at an intermediate point between the two substations SS ₁ and SS ₂ .

13 and 14, when the current change value ΔI ₁ exceeds the threshold value ΔI _set , the DC feeding protection relay device 47 operates. When the current change value ΔI ₂ exceeds the threshold value ΔI _set , the DC feeding protection relay is performed. It shows that the device 57 operates.

In FIG. 13, the DC feeding protection relay device 47 of the substation SS ₁ operates at d = 0 to 0.6, and the DC feeding protection of the substation SS ₂ at d = 0.4 to 1.0. The relay device 57 operates.

On the other hand, in FIG. 14, the DC feeding protection relay device 47 of the substation SS ₁ operates at d = 0 to 0.4, and the DC feeding of the substation SS ₂ at d = 0.6 to 1.0. Although the electric protection relay device 57 operates, an unprotected section occurs at d = 0.4 to 0.6. In other words, an increase in the fault point resistance _Rf causes a section in which both the substations SS ₁ and SS ₂ become unprotected.

Next, (a) an example of the relationship between current and time when the fault point resistance _Rf is 0.6 [Ω], (b) an example of the relationship between current change value and time, (c) An example of the relationship between the interruption operation of the electric circuit breaker and time is shown in FIGS. In FIG. 15, the failure point interval length ratio d = 0, in FIG. 16, the failure point interval length ratio d = 0.25, and in FIG. 17, the failure point interval length ratio d = 0.5. FIG. 15 (c), the FIG. 16 (c), the "act1" in FIG. 17 (c) shows the operation of the substation SS ₁ eaves electric breaker 45, "act2" is eaves substation SS ₂ The operation of the circuit breaker 55 will be described.

From FIG. 15, when d = 0, the feeder circuit breaker 45 of the substation SS ₁ is opened at about t = 50 [ms], and the feeder circuit breaker 55 of the substation SS ₂ is not opened.

From FIG. 16, when d = 0.25, the feeder circuit breaker 45 of the substation SS ₁ is opened at about t = 63 [ms], and then the feeder circuit breaker 55 of the substation SS ₂ is about t = It is released at 135 [ms].

From FIG. 17, when d = 0.5, neither the feeder breaker 45 of the substation SS ₁ nor the feeder breaker 55 of the substation SS _{2 is} opened.

That is, depending on where the fault occurs between the _two substations SS ₁ and SS ₂ , the DC feeder protection relay devices 47 and 57 become the near end operation and the far end non-operation, and the near end is opened. In some cases, the far-end current change value does not reach the threshold value. For this reason, the protection of the feeder 31 is left to the feeder protection relay devices 47 and 57 and the contact breakers 46 and 56 on the near end side.

  Therefore, in order to solve these problems, an embodiment of the present invention provides a DC feeder protection relay device that can improve the sensitivity to failure detection of feeders.

  In order to achieve the above object, a DC feeder protection relay device according to an embodiment is a current that is connected to a circuit breaker or a switch and acquires a current value of a DC feeder that supplies power to an electric vehicle at regular intervals. From the detection unit, a current positive component calculation unit that calculates a current positive component that is a positive component of the current value acquired by the current detection unit, and the first current value acquired by the current detection unit, the current positive component Calculated by the current positive component calculation unit from the first current positive component calculated by the component calculation unit and the second current value acquired by the current detection unit a first predetermined number of times before the first current value. A rush rate calculation unit that calculates a rush rate indicating a change rate of the current positive component based on the second positive current component, and whether or not the rush rate is equal to or higher than a preset rush rate comparison value. If it is determined that it is equal to or greater than the rush rate comparison value, the detection signal Calculated by the positive current component calculation unit from the detection signal output unit to be output, the first positive current component, and the third current value acquired by the current detection unit a second predetermined number of times before the first current value. A current change value calculation unit that calculates a current change value that is a difference from the generated third current positive component, the current change value calculated by the current change value calculation unit, and a current change comparison value that is set in advance, A difference calculation unit that calculates a current change difference that is a difference between the current change difference, and a current change difference calculated by the difference calculation unit is multiplied by a coefficient set in advance to calculate a current change integrated value that is integrated every predetermined time An integrated value calculation unit; a control signal output unit that determines whether or not the current change integrated value is greater than or equal to a predetermined determination value; and when the determination is greater than or equal to the determination value, and the detection Obtaining the detection signal from the signal output unit; One said when acquiring the control signal from the control signal output section, and a trip command output unit for outputting a trip command to open the breaker or the switch.

1 is an overall configuration diagram showing the configuration of a DC feeder protective relay device and its peripheral devices according to the present embodiment. The block diagram which shows the structure of the DC feeding protection relay apparatus which concerns on this embodiment. The block diagram which shows the structure of the relay calculating part of the DC feeding protection relay apparatus which concerns on this embodiment. The flowchart which shows operation | movement of the DC feeding protection relay apparatus which concerns on this embodiment. The flowchart which shows operation | movement of the relay calculating part of the DC feeding protection relay apparatus which concerns on this embodiment. An example which shows the relationship between current change value ₍ DELTA ₎ I _(m) calculated in the DC feeding protection relay apparatus which concerns on this embodiment, and time. An example which shows the relationship between current change value ₍ DELTA _{) I (m)} and current change integrated value ₍ SIGMA ₎ d _(m) and time which were calculated in the DC feeding protection relay apparatus which concerns on this embodiment. An example which shows the relationship between current change value ₍ DELTA ₎ I _(m) calculated in the DC feeding protection relay apparatus which concerns on this embodiment, and time. An example which shows the relationship between current change value ₍ DELTA _{) I (m)} and current change integrated value ₍ SIGMA ₎ d _(m) and time which were calculated in the DC feeding protection relay apparatus which concerns on this embodiment. An example which shows the relationship between current change value ₍ DELTA ₎ I _(m) calculated in the DC feeding protection relay apparatus which concerns on this embodiment, and time. An example which shows the relationship between current change value ₍ DELTA _{) I (m)} and current change integrated value ₍ SIGMA ₎ d _(m) and time which were calculated in the DC feeding protection relay apparatus which concerns on this embodiment. FIG. In the conventional feeding circuit circuit and the fault point interval length ratio d, the change value [Delta] I 1 of the current flowing through current change value [Delta] I _f, the substation SS ₁ per predetermined time in the fault point per predetermined _time, substations per predetermined time An example of the relationship with the change value ΔI _{2 of the} current flowing through the location SS ₂ (R _f = 0.45 [Ω]). In the conventional feeder circuit, the fault section length ratio d, the current change value ΔI _{f at} the fault point per predetermined time, the current change value ΔI _{1 of the} current flowing through the substation SS ₁ per predetermined time, and the substation per predetermined time An example of the relationship with the change value ΔI _{2 of the} current flowing through the location SS ₂ (R _f = 0.7 [Ω]). (A) an example of the relationship between current and time in a conventional feeder circuit, (b) an example of relationship between change value of current and time, and (c) an example of relationship between interruption operation of the feeder circuit breaker and time. (D = 0). (A) an example of the relationship between current and time in a conventional feeder circuit, (b) an example of relationship between change value of current and time, and (c) an example of relationship between interruption operation of the feeder circuit breaker and time. (D = 0.25). (A) an example of the relationship between current and time in a conventional feeder circuit, (b) an example of relationship between change value of current and time, and (c) an example of relationship between interruption operation of the feeder circuit breaker and time. (D = 0.5).

  Hereinafter, embodiments will be described with reference to the drawings.

(Embodiment)
FIG. 1 is an overall configuration diagram showing configurations of a DC feeding protective relay device and peripheral devices thereof according to the present embodiment.

  In the feeding system of the DC electric railway, the substations 1 and 2 are connected to both ends of the feeder 3 in one section, respectively, and the required DC power is supplied to the feeder 3 from each of the substations 1 and 2.

  The substation 1 includes an AC power source 11, a rectifier 12, a disconnector 13, a current transformer (CT) 14, a feeder circuit breaker 15, a communication breaker 16, an AC breaker 17, and a DC feeder protection relay device 100. .

  AC power supplied from the AC power supply 11 is converted into DC power by the rectifier 12, passes through the feeder circuit breaker 15, and is supplied to one end of the electric wire 3.

  Similarly, the substation 2 includes an AC power source 21, a rectifier 22, a disconnector 23, a CT 24, a feeder breaker 25, a communication breaker 26, an AC breaker 27, and a DC feeder protection relay device 200.

  The AC power supplied from the AC power supply 21 is converted into DC power by the rectifier 22, passes through the feeder circuit breaker 25, and is supplied to the other end of the electric wire 3.

  The DC power converted by the rectifiers 12 and 22 is also supplied to the rail 4, and the feeder 3 and the rail 4 supply power to an electric vehicle (not shown).

  The DC feeder protection relay devices 100 and 200 acquire the current value of the feeder line 3 from the CTs 14 and 24, and open the feeder breakers 15 and 25 when a failure or the like occurs in the feeder line 3.

  For example, when the DC feeder protection relay device 100 detects a failure of the feeder 3, the feeder breaker 15 of the substation 1 is opened. Further, since the communication interruption devices 16 and 26 are connected to each other by the communication line 5, the DC feeder protection relay device 100 instructs the communication interruption device 26 of the substation 2 to cut off through the communication interruption device 16 of the substation 1. Output a signal. That is, the feeder circuit breaker 25 is opened by the DC feeder protection relay device 200 or the communication breaker device 26.

  Next, the configuration of the DC feeder protection relay device 100 will be described. FIG. 2 is a block diagram showing the configuration of the DC feeding protection relay device according to the present embodiment. Since the DC feeding protection relay device 200 has the same configuration as the DC feeding protection relay device 100, the description thereof is omitted.

  The DC feeder protection relay device 100 includes an input converter 101, an analog filter 102, an AD converter 103, and a relay calculation unit 104.

  The input converter 101 is a processing unit that is connected to the CT 14 and the analog filter 102, acquires the current value of the feeder 3 measured by the CT 14, and outputs the current value to the analog filter 102.

  The analog filter 102 is a processing unit that is connected to the input converter 101 and the AD converter 103, removes noise and harmonic components of the current value acquired from the input converter 101, and outputs them to the AD converter 103.

  The AD converter 103 is a processing unit that is connected to the analog filter 102 and the relay calculation unit 104, digitizes the current value of the analog data acquired from the analog filter 102, and outputs it to the relay calculation unit 104.

  Next, the configuration of the relay calculation unit 104 will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of the relay operation unit of the DC feeding protection relay device according to the present embodiment.

  The relay calculation unit 104 is realized mainly by a program operated by a CPU, and is stored in a storage medium (not shown) such as an HDD, SSD, or RAM.

  The relay calculation unit 104 includes a current detection unit 201, a positive current component calculation unit 202, a rush rate calculation unit 203, a detection signal output unit 204, a current change value calculation unit 205, a difference calculation unit 206, an integrated value calculation unit 207, and a control signal. An output unit 208 and a trip command output unit 209 are included.

The current detection unit 201 is a processing unit that acquires the current value _Isp digitized by the AD converter 103 at regular intervals.

The current positive component calculation unit 202 is a processing unit that calculates a positive component (current positive component) I ⁺ _(m) of the current value I _{sp (m)} acquired by the current detection unit 201. Specifically, it is calculated by the following mathematical formula (1). Here, m = 1, 2,..., P, and p represents the number of sampling.

In Formula (1), when I _{sp (m)} is negative, the numerator is zero.

The rush rate calculation unit 203 uses a current positive component (first current) calculated by the current positive component calculation unit 202 from the current value (first current value) acquired immediately before (m-th sampling) by the current detection unit 201. Positive component) I ⁺ _(m) and a current positive component calculation unit 202 based on the current value (second current value) acquired by the current detection unit 201 immediately before the first current value (m−1 sampling). Is a processing unit that calculates the rush rate α on the basis of the current positive component (second current positive component) I ⁺ _(m−1) calculated in ₍₁₎ . Specifically, it is calculated by the following mathematical formula (2).

That is, the rush rate indicates the rate of change of the current positive component. Here, the coefficient k _alpha is predetermined, a factor for adjusting the current increase per unit for calculating time.

The detection signal output unit 204 determines whether or not the rush rate calculated by the rush rate calculation unit 203 is equal to or greater than the rush rate comparison value k _α as shown in Equation (3), and the rush rate is the rush rate comparison value k. A processing unit that outputs a detection signal when it is determined that _α is equal to or greater than _α .

α ≧ k _α (3)
Here, the rush rate comparison value k _alpha, a setting value that is pre-settling.

The current change value calculation unit 205 calculates the current calculated by the current positive component calculation unit 202 from the first current positive component and the third current value acquired by the current detection unit 201 a predetermined number of times T before the first current value. This is a processing unit that calculates a current change value ΔI _(m) that is a difference from the positive component (third current positive component) I ⁺ _(m−T) . Specifically, it is calculated by the following mathematical formula (4).

ΔI _(m) = I ⁺ _(m) −I ⁺ _(m−T) (4)
here,
T ≧ 1 (5)
It is.

The difference calculation unit 206 is a processing unit that calculates a current change difference d _(m) that is a difference between the current change value ΔI _(m) calculated by the current change value calculation unit 205 and the current change comparison value k _I. . Specifically, it is calculated by the following mathematical formula (6).

d _(m) = ΔI _(m) −k _I (6)
Here, the current change comparison value k _I is a set point which is pre-settling.

The integrated value calculation unit 207 calculates a current change integrated value Σd _(m) obtained by multiplying the current change difference d _(m) calculated by the difference calculation unit 206 by the coefficient k _d and integrated every fixed time (each sampling). Is a processing unit. Specifically, it is calculated by the following mathematical formula (7).

However, if Σd _(m) becomes negative in Equation (7), it is replaced as Σd _(m) = 0.

The control signal output unit 208 determines whether or not the current change integrated value Σd _(m) calculated by the integrated value calculating unit 207 is equal to or greater than the determination value k _Σd as shown in Equation (8), and determines the determination value k _Σd. When it is determined as above, the processing unit outputs a control signal.

Σd _(m) ≧ k _Σd (8)
The trip command output unit 209 obtains the detection signal output from the detection signal output unit 204 and the trip command to open the feeder circuit breaker 15 when the control signal output from the control signal output unit 208 is acquired. Is a processing unit for outputting.

  The trip command output unit 209 may be configured to output a trip command for opening a switch that replaces the feeder circuit breaker 15.

  Next, the operation of the DC feeder protection relay device 100 will be described with reference to FIG. FIG. 4 is a flowchart showing the operation of the DC feeding protective relay device according to the present embodiment.

  The input converter 101 acquires the current value of the feeder 3 measured by the CT 14 and outputs it to the analog filter 102 (S301).

  The analog filter 102 removes noise and harmonic components of the current value acquired from the input converter 101 and outputs them to the AD converter 305 (S302).

  The AD converter 103 digitizes the current value of the analog data acquired from the analog filter 102 and outputs it to the relay operation unit 104 (S303).

  The relay calculation unit 104 acquires a digitized current value from the AD converter 103, performs a relay calculation, and outputs a trip command to open the power breaker 15 when the condition is satisfied (S304).

  Next, the operation of the relay calculation unit 104 will be described in detail with reference to FIG. FIG. 5 is a flowchart showing the operation of the relay computing unit of the DC feeding protective relay device according to the present embodiment.

  The current detection unit 201 acquires the current value digitized by the AD converter 103 at regular intervals (S401).

  The current positive component calculation unit 202 calculates a current positive component that is a positive component of the current value acquired by the current detection unit 201 (S402).

  The rush rate calculating unit 203 calculates the first current positive component calculated by the current positive component calculating unit 202 from the first current value acquired immediately before by the current detecting unit 201, and the first current value by the current detecting unit 201. The rush rate is calculated based on the second current positive component calculated by the current positive component calculation unit 202 from the second current value acquired immediately before (S403).

  The detection signal output unit 204 determines whether or not the rush rate calculated by the rush rate calculation unit 203 is greater than or equal to the rush rate comparison value (S404).

  The detection signal output unit 204 outputs a detection signal when it is determined that the rush rate calculated by the rush rate calculation unit 203 is equal to or greater than the rush rate comparison value (YES in S404) (S405).

  The current change value calculation unit 205 calculates the third current positive component calculated by the current positive component calculation unit 202 from the first current positive component and the third current value acquired by the current detection unit 201 a predetermined number of times before the first current value. A current change value which is a difference from the current positive component is calculated (S406).

  The difference calculation unit 206 calculates a current change difference which is a difference between the current change value calculated by the current change value calculation unit 205 and the current change comparison value (S407).

  The integrated value calculating unit 207 calculates a current change integrated value obtained by multiplying the current change difference calculated by the difference calculating unit 206 by a coefficient and integrating the current change difference every fixed time (every sampling) (S408).

  The control signal output unit 208 determines whether or not the current change integrated value calculated by the integrated value calculating unit 207 is greater than or equal to a determination value (S409).

  The control signal output unit 208 outputs a control signal when the current change integrated value is determined to be greater than or equal to the determination value (YES in S409) (S410).

  The trip command output unit 209 obtains the detection signal output from the detection signal output unit 204 and the trip command to open the feeder circuit breaker 15 when the control signal output from the control signal output unit 208 is acquired. Is output (S411).

  Next, simulation results are shown.

FIG. 6 is an example showing the relationship between the current change value ΔI _(m) calculated in the DC feeding protective relay device according to the present embodiment and time.

FIG. 7 is an example showing the relationship between the current change value ΔI _(m) and the current change integrated value Σd _(m) calculated in the DC feeding protective relay device according to this embodiment and time.

6 and 7, failure point resistance R _f = 1.0 [Ω], failure point section length ratio d = 0, current change comparison value k _I = 500 [A], determination value k _Σd = 10000, threshold ΔI _set = 1000 [A].

The threshold value ΔI _set is a threshold value when the current change value ΔI _(m) is used as an operation determination for opening the feeder circuit breakers 15 and 25. In this case, the current change value ΔI _(m) exceeds the threshold value ΔI _set . Then, the feeder circuit breakers 15 and 25 are opened. The same applies hereinafter.

6 and 7, ΔI _{1 (m)} is a current change value calculated by the DC feeder protection relay device 100 of the substation 1, and ΔI _{2 (m)} is a DC feeder protection relay of the substation 2. The current change value calculated by the apparatus 200 is represented, and so on.

In FIG. 7, Σd _{1 (m)} is a current change integrated value calculated by the DC feeding protection relay device 100 of the substation 1, and Σd _{2 (m)} is a DC feeding protection relay of the substation 2. This represents the current change integrated value calculated by the apparatus 200, and so on.

As shown in FIG. 6, when the current change value ΔI _(m) is used as the operation determination, the feeder circuit breaker 15 of the near-end side substation 1 is opened under the above conditions, but the far-end side substation is changed. The feeder circuit breaker 25 at location 2 is not opened.

  On the other hand, as shown in FIG. 7, according to the DC feeding protection relay device according to the present embodiment, the DC feeding protection relay device 100 of the near-end side substation 1 and the far-end side substation 2 Both of the DC feeder protection relay devices 200 satisfy Expression (8).

  Note that the DC feeder protective relay device 200 of the substation 2 satisfies Expression (8) at t = 96 [ms].

That is, in a DC feeding circuit protective relay devices 100 and 200, the current change value [Delta] I _(m) to be the difference between the current change comparison value _{k I} the current change difference _{d (m),} is integrated by multiplying the coefficient _{k d} Thus, since the current change integrated value Σd _(m) is equal to or greater than the determination value k _Σd , both the feeder circuit breakers 15 and 25 can be opened.

FIG. 8 is an example showing the relationship between the current change value ΔI _(m) calculated in the DC feeder protection relay device according to the present embodiment and time.

FIG. 9 is an example showing the relationship between the current change value ΔI _(m) and the current change integrated value Σd _(m) calculated in the DC feeding protective relay device according to the present embodiment and time.

8 and 9, failure point resistance R _f = 1.0 [Ω], failure point section length ratio d = 0.2, current change comparison value k _I = 500 [A], judgment value k _Σd = 10000, The threshold value ΔI _set = 1000 [A].

As shown in FIG. 8, when the current change value ΔI _(m) is used as the operation determination, the feeder circuit breaker 15 of the near-end side substation 1 is opened under the above conditions, but the far-end side substation is changed. The feeder circuit breaker 25 at location 2 is not opened.

  On the other hand, as shown in FIG. 9, according to the DC feeding protection relay device according to the present embodiment, the DC feeding protection relay device 100 of the near-end side substation 1 and the far-end side substation 2 Since both of the DC feeder protection relay devices 200 satisfy Formula (8), both feeder feeders 15 and 25 can be opened.

  The DC feeding protection relay device 100 of the substation 1 satisfies the formula (8) at t = 29 [ms], and the DC feeding protection relay device 200 of the substation 2 has t = 99 [ms. ] Satisfies Formula (8).

FIG. 10 is an example showing the relationship between the current change value ΔI _(m) calculated in the DC feeding protective relay device according to the present embodiment and time.

FIG. 11 is an example showing the relationship between the current change value ΔI _(m) and the current change integrated value Σd _(m) calculated in the DC feeding protective relay device according to the present embodiment and time.

10 and 11, the failure point resistance R _f = 1.0 [Ω], the failure point interval length ratio d = 0.2, the current change comparison value k _I = 500 [A], the determination value k _Σd = 10000, The threshold value ΔI _set = 1000 [A].

As shown in FIG. 10, when the current change value ΔI _(m) is used as the operation determination, the feeding circuit breaker 15 of the near-end side substation 1 and the feeding line of the far-end side substation 2 are used under the above conditions. Neither the circuit breaker 25 is opened.

  On the other hand, as shown in FIG. 11, according to the DC feeding protection relay device according to the present embodiment, the DC feeding protection relay device 100 of the near-end side substation 1 and the far-end side substation 2 Since both of the DC feeder protection relay devices 200 satisfy Formula (8), both feeder feeders 15 and 25 can be opened.

Note that both the DC feeding protection relay device 100 of the substation 1 and the DC feeding protection relay device 200 of the substation 2 satisfy Expression (8) at t = 86 [ms].

  As described above, according to the DC feeder protection relay device according to the present embodiment, the sensitivity to the failure detection of the feeder 3 can be improved.

  This embodiment is presented as an example and is not intended to limit the scope of the invention. The present embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the invention described in the claims and equivalents thereof as well as included in the scope and spirit of the invention.

1, 2, SS ₁ , SS ₂ ... substation 3, 31 ... feeder 4, 4, 32 ... rail 5, 34 ... communication line 11, 21, 41, 51 ... AC power supply 12, 22, 42, 52 ... rectifier 13, 23 ... Disconnector 14, 24, 43, 53 ... Current transformer (CT)
15, 25, 45, 55... Feeder circuit breaker 16, 26, 46, 56... Contact breaker 17, 27. ... input converter 102 ... analog filter 103 ... AD converter 104 ... relay calculation unit 201 ... current detection unit 202 ... current positive component calculation unit 203 ... rush rate calculation unit 204 ... detection signal output unit 205 ... current change calculation unit 206 ... Difference calculation unit 207 ... integrated value calculation unit 208 ... control signal output unit 209 ... trip command output unit

Claims (1)

A current detector that is connected to a circuit breaker or a switch and obtains a current value of a DC feeder supplying power to an electric vehicle at regular intervals;
A current positive component calculation unit that calculates a current positive component that is a positive component of the current value acquired by the current detection unit;
Obtained from the first current value obtained by the current detection unit, the first current positive component calculated by the current positive component calculation unit, and the current detection unit by a first predetermined number of times before the first current value. A rush rate calculating unit that calculates a rush rate indicating a change rate of the current positive component based on the second current value calculated and the second current positive component calculated by the current positive component calculating unit;
It is determined whether or not the rush rate is equal to or higher than a preset rush rate comparison value, and when it is determined to be equal to or higher than the rush rate comparison value, a detection signal output unit that outputs a detection signal;
The first current positive component and the third current positive component calculated by the current positive component calculation unit from the third current value acquired by the current detection unit a second predetermined number of times before the first current value; A current change value calculation unit that calculates a current change value that is a difference between
A difference calculation unit that calculates a current change difference that is a difference between the current change value calculated by the current change value calculation unit and a current change comparison value set in advance;
An integrated value calculating unit that calculates a current change integrated value obtained by multiplying the current change difference calculated by the difference calculating unit by a coefficient set in advance and integrated every predetermined time;
It is determined whether or not the current change integrated value is equal to or higher than a preset determination value, and when it is determined to be equal to or higher than the determination value, a control signal output unit that outputs a control signal;
A trip command output unit that outputs a trip command to open the circuit breaker or the switch when the detection signal is acquired from the detection signal output unit and the control signal is acquired from the control signal output unit; Having a DC feeder protection relay device.

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