JP2014239568A - Protection relay for railway feeder circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protection relay for railway feeder circuit, capable of achieving labor saving of maintenance without degrading reliability of protective operations.SOLUTION: The protection relay includes: a hetero-phase fault contact detection element 1a for detecting hetero-phase fault contact on the basis of interphase voltages V1-V4 and a setting value 14a; and a setting value change element 1b for changing the setting value 14a to a proper value and writing a changed setting value 32a into the hetero-phase fault contact detection element 1a when it is detected that a voltage vector of the interphase voltages V1-V4 is under an unbalanced state, on the basis of the interphase voltages V1-V4.

Description

  The present invention relates to a protective relay device for an electric railway feeding circuit that feeds electricity with a Scott connection transformer.

  In the electric railway substation, a Scott connection transformer is installed to convert the three-phase AC voltage into two sets of single-phase AC voltages and supply them to the overhead and downstream overhead lines to drive the AC electric vehicle. Yes. And protection with a different phase intrusion detection element for detecting an accident in which two sets of single-phase AC voltages are generated in the power system on the secondary side of the Scott connection transformer (different phases). Relay devices are known. The secondary-side voltage of the Scott connection transformer is input to this heterogeneous contact detection element via an instrument transformer. Furthermore, in the heterogeneous cross detection element, the interphase voltage is calculated based on the input voltage, and the calculated scalar amount of the interphase voltage is compared with a predetermined set value, and the minimum of the scalar amounts of the interphase voltage is calculated. When the value is smaller than the settling value, a method for detecting a mixed-phase accident is disclosed (for example, Non-Patent Document 1 below).

  Further, in the conventional technique described in Patent Document 1 below, the protection calculation is performed using a settling value selected from a plurality of settling values set in advance in the storage unit.

JP 2006-311764 A

Yoshifumi Mochinaga, “Electrical Railway Engineering”, Ace Publishing Co., March 1995, p. 122

  However, in the prior art of the above-mentioned Patent Document 1, it is necessary for a person to calculate a set value based on the inter-phase voltage calculated by the out-of-phase detection element, and record the set value. When it is necessary to set a new set value due to the fact that the operation has been performed, the work of recalculating the set value has occurred, and it has not been possible to save labor.

  On the other hand, an appropriate settling value cannot be obtained automatically by simply calculating the settling value from the voltage value input to the heterogeneous mixture detection element. There are two steady-state voltage vectors based on the voltage between the different phases that are measured when a mixed-phase accident does not occur (in steady state). Of the two steady-state voltage vectors, the measurement is performed with the feeder circuit breaker open. The resulting voltage vector is unbalanced. When determining the settling value, it is necessary to slow down the detection sensitivity in order to avoid misjudgment of a heterogeneous accident when the voltage vector is in an unbalanced state. However, if the settling value is simply set to a large value, the detection sensitivity becomes dull and it may not be possible to detect a mixed-phase accident, and if the power system is repaired as described above, Since the voltage vector in the unbalanced state also fluctuates, it is necessary to obtain an appropriate settling value in consideration of the fluctuation. That is, the set value must be set to a value that does not make an accident determination even when the voltage vector is in an unbalanced state when no accident occurs, and that makes an accident determination when an accident occurs.

  As described above, the conventional technique has a problem in that an appropriate settling value cannot be automatically generated and updated.

  This invention is made | formed in view of the above, Comprising: It aims at obtaining the protection relay apparatus for electric railway feeding circuits which can aim at labor saving of a maintenance.

  In order to solve the above-described problems and achieve the object, the present invention is used in a railway circuit that is supplied with a secondary voltage of a Scott connection transformer that converts a three-phase power source into two sets of single-phase power sources. It is a protective relay device for an electric railway circuit, which calculates a voltage between different phases based on the secondary voltage of each of the two sets of single-phase power supplies, and based on the voltage between the different phases and a set value set When detecting that the voltage vector of the interphase voltage is in an unbalanced state based on the interphase voltage, the minimum value of the interphase voltage and the interphase detection element In accordance with the comparison result with the settling value recorded in the setpoint, the settling value set in the out-of-phase contact detection element is not detected even if the voltage vector is in an unbalanced state when no out-of-phase contact occurs, and Detect phase contact when out-of-phase contact occurs And a settling value changing element that writes the changed set value to the heterogeneous mixture detection element when the settling value set in the heterogeneous mixture detection element is allowed to be changed. To do.

  According to the present invention, since it is configured to automatically change to an appropriate value based on the inter-phase voltage obtained from the secondary voltage of the Scott connection transformer, it is possible to reduce the maintenance labor. Play.

FIG. 1 is a diagram showing a configuration of an AC power feeding system for an electric railway provided with a protective relay device for an electric railway feeding circuit according to Embodiment 1 of the present invention. FIG. 2 is a diagram illustrating the function of the protective relay device for the electric railway feeding circuit shown in FIG. FIG. 3 is a diagram illustrating a steady-state voltage vector in an equilibrium state. FIG. 4 is a diagram showing a steady voltage vector in an unbalanced state. FIG. 5 is a diagram showing the function of the protective relay device for electric railway feeding circuits according to Embodiment 2 of the present invention. FIG. 6 is a diagram showing the function of the protective relay device for electric railway feeding circuits according to Embodiment 3 of the present invention.

  DESCRIPTION OF EMBODIMENTS Embodiments of a protective relay device for an electric railway feeding circuit according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of an AC power feeding system for an electric railway provided with a protective relay device for an electric railway feeding circuit according to Embodiment 1 of the present invention. FIG. 2 is a diagram illustrating the function of the protective relay device for the railway service shown in FIG. FIG. 3 is a diagram illustrating a steady-state voltage vector in an equilibrium state. FIG. 4 is a diagram showing a steady voltage vector in an unbalanced state.

  The AC power supply system for electric railways consists of the Scott connection transformer 2 connected to the lower power system side of the power transmission equipment of the electric power company and the power supply connected to the secondary circuit 3 of the M seat power supply of the Scott connection transformer 2 The circuit breakers 21 and 22, the feeder circuit breakers 23 and 24 connected to the secondary circuit 4 of the T-seat power source of the Scott connection transformer 2, and the secondary side of the feeder circuit breakers 21 and 22 A single transformer 51 and a single transformer 52 connected to the secondary side of the feeder circuit breakers 23 and 24 are configured.

  In the Scott connection transformer 2, the three-phase power supplied from the electric power company is converted into a M-phase and a T-seat, which are single-phase two-phase power supplies having a phase difference of 90 degrees, Power is supplied to feeder lines 41, 42, 43, 44 through feeder circuit breakers 21, 22, 23, 24.

  An instrument transformer 7 is provided on the secondary line 3 of the M seat power source, and an instrument transformer 8 is provided on the secondary line 4 of the T seat power source.

  Protective relay device 1 for electric railway circuits (hereinafter referred to as “protective relay device 1”) is generated on the secondary side of Scott connection transformer 2 based on the voltage value detected by instrument transformers 7 and 8. Detects the presence or absence of a mixed-phase accident and does not open the feeder breakers 21 to 24 when the train load current flows through the feeder lines 41 to 44. The vessels 21 to 24 are opened.

  In FIG. 2, the protective relay device 1 includes a heterogeneous mixture detection element 1 a and a set value changing element 1 b as main components.

  The heterogeneous mixture detection element 1a includes a voltage input unit 11, an interphase voltage calculation unit 12, a relay determination processing unit 13, and a set value storage unit 14.

  The voltage input unit 11 converts the secondary voltage values Vm1, Vm2, Vt1, and Vt2 detected by the instrument transformers 7 and 8 from analog values to digital values 11a. The inter-phase voltage calculation unit 12 generates the inter-phase voltage 12a (V1 to V4) by vector synthesis of the secondary voltage values Vm1, Vm2, Vt1, and Vt2 converted to the digital value 11a.

  The relay determination processing unit 13 obtains the respective scalar amounts of the inter-phase voltage 12a (V1, V2, V3, V4), and compares each scalar amount with the set value 14a recorded in the set value storage unit 14. Then, for example, when the smallest value among the respective scalar amounts is smaller than the set value, the relay determination processing unit 13 determines that a heterogeneous mixture accident has occurred and outputs the open signal 13a of the feeder circuit breakers 21 to 24. . This protects the power system.

  The set value changing element 1b includes a voltage vector state determining unit 31, a set value changing unit 32, and a set value writing unit 34.

  The voltage vector state determination part 31 calculates | requires the scalar quantity of each interphase voltage V1-V4 based on each interphase voltage V1-V4 of the interphase voltage 12a. Further, the voltage ratio difference V% 1, V% 2 of the voltage vector between the opposed interphase voltages V1 to V4 is obtained from each scalar quantity.

Furthermore, the voltage vector state determination part 31 calculates | requires balance factor (DELTA) V% from difference voltage ratio V% 1, V% 2. The differential voltage ratios V% 1 and V% 2 and the balance ratio ΔV% are obtained, for example, from the equations (1) to (3).
V% 1 = (V1-V3) / (V1 + V3) (1)
V% 2 = (V2−V4) / (V2 + V4) (2)
ΔV% = | V% 1−V% 2 | (3)

  Further, the voltage vector state determination unit 31 compares a predetermined value (voltage vector state determination value A) for determining whether the voltage vector is in an equilibrium state or an unbalanced state with the balance factor ΔV%.

  When the balance ratio ΔV% is equal to or greater than the voltage vector state determination value A, the voltage vector state determination unit 31 determines that the voltage vector (V1 to V4) is in an equilibrium state. According to the balanced state voltage vector 100 shown in FIG. 3, V1 is a voltage between the secondary voltage values Vm1 and Vt1, V2 is a voltage between the secondary voltage values Vt1 and Vm2, and V3 is a secondary voltage. A voltage between the values Vm2 and Vt2, and V4 is a voltage between the secondary voltage values Vt2 and Vm1. The secondary voltage value Vm1 is equal to and orthogonal to the value of the secondary voltage value Vt1, the secondary voltage value Vm2 is equal to and orthogonal to the value of the secondary voltage value Vt2, and the secondary voltage values Vm1, Vt1, Vm2, and Vt2 The vectors are adjacent in order. The phase difference between the secondary voltage values Vm1, Vt1, Vm2, and Vt2 is 90 °.

  On the other hand, when the balance factor ΔV% is less than the voltage vector state determination value A, the voltage vector state determination unit 31 determines that the voltage vector is in an unbalanced state. According to the unbalanced voltage vector 101 shown in FIG. 4, the secondary voltage value Vt1 is larger and orthogonal to the secondary voltage value Vm1, and the secondary voltage value Vt2 is smaller than the secondary voltage value Vm2. The phase differences between the secondary voltage values Vm1, Vt1, Vm2, and Vt2 are 90 °.

  When the voltage vector state determination unit 31 determines that the voltage vector 101 is in an unbalanced state, the voltage vector state determination unit 31 outputs the determination result unbalanced state voltage vector information 15 and the interphase voltages V1 to V4 as the determination unit result 31a.

  When the determination unit result 31a is input, the set value change unit 32 compares the smallest value Vmini among the different phase voltages V1 to V4 with the set value 14a recorded in the set value storage unit 14. The difference between the value Vmini and the settling value 14a or the ratio between the value Vmini and the settling value 14a is obtained.

  Further, the set value changing unit 32 detects the set value 14a according to the comparison result when the out-of-phase mixture does not occur, even if the voltage vector is in an unbalanced state, and does not detect the out-of-phase mix. Change to a value that detects. Specifically, when the comparison result is larger than the predetermined value C, the difference between the comparison result and the predetermined value C is subtracted from the set value 14a to generate a new set value 32a. When the comparison result is smaller than the predetermined value C, The difference between the comparison result and the predetermined value C is added to the set value 14a to generate a new set value 32a. The generated set value 32 a is output to the set value writing unit 34.

  The predetermined value C is, for example, a value that is set so that when a different phase mixture does not occur, even if the voltage vector is in an unbalanced state, the different phase mixture is not detected, and when the different phase mixture occurs, the phase mixture is detected.

  The set value writing unit 34 receives the set value change permission condition 33 and the set value 32a. The set value writing unit 34 writes the set value 32 a to the set value storing unit 14 when the set value change permission condition 33 is input. That is, the set value in the set value storage unit 14 is rewritten to a new set value (set value 32a) only when the set value change is permitted.

  The set value change permission condition 33 is information for permitting the setting value 14a in the set value storage unit 14 to be changed to a new set value 32a. For example, the set value change setting condition provided in the protective relay device 1 is set. Output when a push button switch (not shown) is manually operated. That is, the protective relay device 1 according to the present embodiment has a new set value 32a only when the set value change permission condition 33 is manually input so as not to hinder the operation of the AC electric vehicle 6. Is overwritten in the set value storage unit 14.

  Next, the operation of the protective relay device 1 will be described. In the protective relay device 1, the inter-phase voltages V1 to V4 are generated based on the secondary voltage values Vm1 to Vt2 detected by the instrument transformers 7 and 8. When the voltage vector 101 in an unbalanced state is determined by the interphase voltages V1 to V4, the comparison result between the smallest value Vmini and the set value 14a among the interphase voltages V1 to V4 is the predetermined value C. When the set value 32 a is generated and the set value change permission condition 33 is input, the set value 32 a is written in the set value storage unit 14. In the protective relay device 1, when the relay determination is performed based on the set value 14 a stored in the set value storage unit 14 and the out-of-phase voltages V <b> 1 to V <b> 4, it is recognized that an out-of-phase accident has occurred. An open signal 13a is output to the post-breaker circuit breakers 21 to 24, and the power system is protected.

  As described above, the protective relay device 1 according to the present embodiment is based on the secondary voltages (secondary voltage values Vm1, Vm2, Vt1, Vt2) of the two sets of single-phase power supplies. V1 to V4 are calculated, and the heterogeneous mixture detection element 1a that detects the heterogeneous mixture based on the interphase voltage and the set value 14a, and the voltage vector of the interphase voltage based on the interphase voltage is in an unbalanced state. When it is detected, the set value 14a set in the out-of-phase contact detection element 1a is used as the out-of-phase contact according to the comparison result between the minimum value of the out-of-phase voltage and the set value 14a recorded in the out-of-phase detection element 1a. When non-occurrence, even if the voltage vector is in an unbalanced state, it does not detect out-of-phase contact, and when out-of-phase contact occurs, it is changed to a value that detects phase contact, and the setting value set for the out-of-phase contact detection element can be changed. When And a setting value changing element 1b to write to the changed set point 32a heterophasic incompatible detecting element 1a. With this configuration, the set value in the heterogeneous mixture detection element 1a can be automatically rewritten, and maintenance labor can be saved without lowering the reliability of the protection operation.

  Further, the set value changing element 1b receives the changed set value 32a when the change permission information (set value change permission condition 33) of the set value 14a set in the out-of-phase contact detection element 1a is input. The set value writing unit for writing to 1a is provided. In the case of this configuration, the settling value 32a is written into the heterogeneous mixture detection element 1a only when the settling value change permission condition 33 is input, so that the reliability of the protective relay device 1 can be improved.

Embodiment 2. FIG.
FIG. 5 is a diagram showing the function of the protective relay device for electric railway feeding circuits according to Embodiment 2 of the present invention. The difference from the first embodiment is that the change of the set value is interrupted when the open signal 13a from the relay determination processing unit 13 is input to the set value changing element 1b. Hereinafter, the same reference numerals are given to the same parts as those in the first embodiment, and the description thereof will be omitted, and only different parts will be described here.

  The set value changing element 1b of FIG. 5 includes a voltage vector state determining unit 31, a set value changing unit 32, and a set value writing unit 34, as in the first embodiment. The set value changing element 1b determines whether or not the open signal 13a from the relay determination processing unit 13 is input, and interrupts the set value changing operation when the open signal 13a is input. With this configuration, the settling value 32a calculated by the interphase voltages V1, V2, V3, and V4 when the heterophasic accident is detected is not written to the settling value storage unit 14, and is more than that of the first embodiment. The reliability of the set value 32a can be increased.

Embodiment 3 FIG.
FIG. 6 is a diagram illustrating functions of the protective relay device for electric railway feeding circuits according to the third embodiment of the present invention. The difference from the first embodiment is that the set value is changed only when the non-open signal 13b from the relay determination processing unit 13 is input to the set value changing element 1b. Hereinafter, the same reference numerals are given to the same parts as those in the first embodiment, and the description thereof will be omitted, and only different parts will be described here.

  The set value changing element 1b in FIG. 6 includes a voltage vector state determining unit 31, a set value changing unit 32, and a set value writing unit 34 as in the first embodiment. The set value changing element 1b determines whether or not the non-open signal 13b from the relay determination processing unit 13 is input. When the non-open signal 13b is input, the set value changing element 1b performs an operation of changing the set value. With this configuration, only the settling value 32a calculated with the out-of-phase voltages V1, V2, V3, and V4 when no out-of-phase accident is detected is written in the settling value storage unit 14, so that the settling is greater than in the first embodiment. The reliability of the value 32a can be increased.

  Note that the protective relay device for electric railway feeding circuit shown in the present embodiment shows an example of the content of the present invention, and can be combined with another known technique, or the present invention. Of course, it is possible to change and configure such as omitting a part without departing from the gist of the present invention.

  As described above, the present invention can be applied to a protective relay device for electric railway circuits, and in particular, an electric railway circuit capable of saving maintenance without reducing the reliability of the protective operation. It is useful as an invention that can provide a protective relay device for use.

DESCRIPTION OF SYMBOLS 1 Protective relay device for electric railways, 1a Interphase detection element, 1b Setting value changing element, 2 Scott connection transformer, 3, 4 Secondary circuit, 6 AC electric vehicle, 7, 8 Instrument transformer, 11 Voltage input unit, 11a digital value, 12 phase-to-phase voltage calculation unit, 12a phase-to-phase voltage, 13 relay determination processing unit, 13a open signal, 13b non-open signal, 14 settling value storage unit, 14a settling value, 15 unbalanced state voltage Vector information 21, 22, 23, 24 Feeder circuit breaker, 31 Voltage vector state determination unit, 31a Determination unit result, 32 Set value change unit, 32a Set value, 33 Set value change permission condition, 34 Set value write , 41, 42, 43, 44 feeder, 51, 52 autotransformer, 100 balanced voltage vector, 101 unbalanced voltage vector, TP trip signal, Vm1, Vm2, V 1, Vt2 secondary voltage value.

Claims (6)

A protective relay device for an electric railway circuit used in an electric railway circuit supplied with a secondary voltage of a Scott connection transformer that converts a three-phase power source into two sets of single-phase power sources,
A cross-phase contact detection element that calculates a cross-phase voltage based on the secondary voltage of each of the two sets of single-phase power supplies, and detects the cross-phase contact based on the cross-phase voltage and a set value set;
When it is detected that the voltage vector of the interphase voltage is in an unbalanced state based on the interphase voltage, the comparison result between the minimum value of the interphase voltage and the set value recorded in the heterogeneous mixture detection element Accordingly, the set value set in the out-of-phase contact detection element is a value that does not detect out-of-phase contact even when the voltage vector is in an unbalanced state when no out-of-phase contact occurs, and detects the out-of-phase contact when out-of-phase contact occurs. When the set value set in the out-of-phase detection element is allowed to be changed, the set value change element that writes the changed set value to the out-of-phase detection element,
A protective relay device for an electric railway circuit characterized by comprising: The settling value changing element is:
2. The protective relay device for a railway railway circuit according to claim 1, wherein when the out-of-phase contact is detected, the change of the set value set in the out-of-phase detection element is interrupted. The settling value changing element is:
2. The protective relay device for a railway railway circuit according to claim 1, wherein when the out-of-phase contact is not detected, the set value set in the out-of-phase detection element is changed.   The said set value change element calculates | requires the difference of the set value set to the said different phase intrusion detection element, and the minimum value of the said different phase voltage as said comparison result, The any one of Claims 1-3 characterized by the above-mentioned. The protective relay device for electric railway feeders described in 1.   The settling value changing element obtains, as the comparison result, a ratio between a settling value set in the out-of-phase detection element and a minimum value of the out-of-phase voltage. The protective relay device for electric railway feeders described in 1. The settling value changing element is:
The set value writing unit that writes the changed set value to the out-of-phase detection element when the set value change permission information set in the out-of-phase detection element is input. The protective relay device for an electric railway circuit according to any one of 1 to 5.

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