JP2009077562A - Two-phase bushing current transformer and protective relay device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-phase bushing current transformer enabling further reduction of the installation number of current transformers and short circuit protective relays which are used to protect a three-phase AC circuit from a short circuit failure, and to provide a protective relay device. <P>SOLUTION: An R-phase and an S-phase of a power transmission line are led through in the reverse direction in an annular iron core of the two-phase bushing current transformer 10 installed in the power transmission line, in which the R-phase is led through only one time and the S-phase is led through two times. Upon detecting a short circuit failure on the basis of a short circuit current I<SB>Ry</SB>inputted from the two-phase bushing current transformer 10, an overcurrent relay 4 collectively interrupts first-third breakers 2<SB>1</SB>-2<SB>3</SB>installed in the R-phase, S-phase and T-phase of the power transmission line. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a two-phase through current transformer and a protective relay device, and in particular, a two-phase suitable for reducing the number of installed current transformers and short-circuit protective relays for protecting a three-phase AC circuit from a short-circuit accident. The present invention relates to a through current transformer and a protective relay device.

  Conventionally, in a three-phase AC circuit, an overcurrent relay (OC) is installed for each phase in order to protect the three-phase AC circuit from a short circuit accident (see, for example, Patent Document 1 below).

Moreover, in the power transmission / distribution line of the terminal circuit, etc., the short circuit current flows in two phases, and an overcurrent relay is installed only in the two phases to reduce the equipment cost. For example, as shown in FIG. 19, first and second current transformers (CT) 3 ₁ , 3 ₂ installed in the R phase and the T phase, respectively, among the R phase, S phase, and T phase of the transmission and distribution line. When the first and second overcurrent relays (OC) 4 ₁ , 4 ₂ are connected to each other and a short-circuit accident occurs in the transmission / distribution line, the transmission / distribution line depends on the aspect of the accident as shown below. The _first to _third circuit breakers 2 ₁ to 2 ₃ installed in the R phase, S phase, and T phase are collectively disconnected by the first and second overcurrent relays 4 ₁ and 4 ₂ , respectively.
(1) In the case of a short-circuit accident between the R phase and the S phase Since a short circuit current flows in the R phase and S phase of the transmission and distribution line, the short circuit current input from the _first current transformer 31 installed in the R phase Based on this, the first overcurrent relay 4 ₁ operates to collectively shut off the _first to _third circuit breakers 2 ₁ to 2 ₃ .
(2) In the case of a short-circuit accident between S-phase and T-phase Since a short-circuit current flows in the S-phase and T-phase of the transmission and distribution line, the short-circuit current input from the _second current transformer 3 ₂ installed in the T-phase Based on this, the second overcurrent relay 4 ₂ operates to cut off the _first to _third circuit breakers 2 ₁ to 2 ₃ at _once .
(3) In the case of a short circuit accident between the T phase and the R phase Since a short circuit current flows in the R phase and the T phase of the transmission and distribution line, the first and second current transformers 3 ₁ installed in the R phase and the T phase, respectively. , 3 ₂ , the first and second overcurrent relays 4 ₁ , 4 ₂ operate based on the short-circuit currents respectively input from the _first to _third circuit breakers 2 ₁ to 2 ₃ .
(4) In the case of a short circuit accident between the R phase, the S phase, and the T phase Since a short circuit current flows in the R phase, the S phase, and the T phase, the first and second current transformers installed in the R phase and the T phase, respectively. The first and second overcurrent relays 4 ₁ and 4 ₂ operate on the basis of the short-circuit currents input from 3 ₁ and 3 ₂ , respectively, and collectively cut off the _first to _third circuit breakers 2 ₁ to 2 _3. .
JP-A-8-005659

  However, since three or two current transformers and overcurrent relays are installed for each transmission / distribution line, a request to further reduce the installation cost by reducing the number of current transformers and overcurrent relays installed. There is.

  Such a request is a current differential relay for protecting a three-phase AC circuit from a short-circuit accident inside the transformer, and an overcurrent protection relay used for protecting the three-phase AC circuit from a short-circuit accident in the premises. Current detection, pulse code modulation current differential relay (PCM current differential relay) used on the power supply bus side and power receiving end bus side of the transmission / distribution line, and the current detection sensitivity is corrected according to the voltage value There is also an overcurrent relay with voltage suppression and the like having a function to perform.

  An object of the present invention is to provide a two-phase through current transformer and a protective relay device that can further reduce the number of installed current transformers and short-circuit protective relays for protecting a three-phase AC circuit from a short-circuit accident. It is in.

The two-phase through current transformer of the present invention is a two-phase through current transformer (10; 10 ₁ , 10 ₂ ) for detecting a short-circuit current flowing in each phase of a three-phase AC circuit, and includes a secondary coil. An arbitrary two phases of the three-phase AC circuit are passed through the wound annular iron core in different directions for different times.
Here, one of the two arbitrary phases of the three-phase alternating current circuit is penetrated in the polarity direction of the two-phase through current transformer, and one of the arbitrary two phases of the three-phase alternating current circuit The other one phase may be penetrated in the opposite polarity direction of the two-phase through current transformer.
Computation processing means for judging the accident aspect of the short-circuit accident of the three-phase AC circuit and multiplying the short-circuit current detected by the two-phase through current transformer by a predetermined multiple according to the determination result of the accident aspect. Also good.
The protective relay device of the present invention is a protective relay device for protecting a three-phase AC circuit from a short circuit accident, and is input from the two-phase through current transformer of the present invention and the two-phase through current transformer. When a short circuit accident is detected based on the short circuit current, a short circuit protective relay that collectively shuts off the circuit breakers installed in each phase of the three-phase AC circuit is provided.
Here, the two-phase through current transformer and the short-circuit protection relay may be installed only for the arbitrary two phases of the three-phase AC circuit.
The protective relay device is configured to determine an accident aspect of the short-circuit accident of the three-phase AC circuit, and an accident aspect of the accident aspect determination means in the short-circuit current detected by the two-phase through current transformer. You may further comprise the arithmetic processing means which multiplies the predetermined multiple according to the determination result.
The accident mode determination means determines whether the three-phase AC circuit has three line voltages (V _RS , V _ST , V _TR ), three phase voltages (V _R , V _S , V _T ) or a phase / line voltage. Based on this, the accident aspect of the short-circuit accident of the three-phase AC circuit or the three-phase AC circuit may be determined.
The accident mode determination means is based on the voltage value and phase of one line voltage (V _RS , V _ST , V _TR ) and one phase voltage (V _R , V _S , V _T ) of the three-phase AC circuit. Thus, the accident aspect of the short circuit accident of the three-phase AC circuit may be determined.
The accident mode judging means is configured to _detect a voltage value and a phase of one line voltage (V _RS , V _ST , V _TR ) of the three-phase AC circuit and a short-circuit current (I _Ry) input from the two-phase through current transformer. ) Phase of the three-phase AC circuit may be determined on the basis of the phase).
The first phase voltage (V _R ) of the three-phase AC circuit is in the polarity direction, and the second phase voltage (V _S ) of the three-phase AC circuit is in the opposite polarity direction. The first to second phases are used for determining the accident aspect of the short-circuit fault of the three-phase AC circuit, where the secondary side is connected so as to synthesize the phase voltage (V _T ) by doubling in the opposite polarity direction. An accident mode judging transformer (110) for obtaining a composite voltage (V _RS-2T ) of the phase voltages of the three phases, wherein the accident mode judging means is inputted from the accident mode judging transformer. The accident aspect of the short-circuit accident of the three-phase AC circuit may be determined based on the voltage value and phase of the combined voltage and the phase of the short-circuit current (I _Ry ) input from the two-phase through current transformer. .
The first phase voltage (V _R ) of the three-phase AC circuit is in the polarity direction, and the second phase voltage (V _S ) of the three-phase AC circuit is in the opposite polarity direction. The first to third are used to determine the accident aspect of the short-circuit accident of the three-phase AC circuit in which the secondary side is connected so that the phase voltage (V _T ) is doubled and synthesized in the polarity direction. And an accident mode determination transformer (120) for obtaining a composite voltage (V _{R-S + 2T} ) of the phases of the phases, and the accident mode determination means is input from the accident mode determination transformer Even if the accident aspect of the short circuit accident of the three-phase AC circuit is determined based on the voltage value and phase of the synthesized voltage and the phase of the short circuit current (I _Ry ) input from the two-phase through current transformer Good.
The first phase voltage (V _R ) of the three-phase AC circuit is multiplied by a in the polar direction or in the opposite polarity direction, and the second phase voltage (V _S ) of the three-phase AC circuit is changed in the polarity direction or oppositely. The secondary side is wired so that the third phase voltage (V _T ) of the three-phase AC circuit is multiplied by c in the polar direction or the opposite polarity direction to be synthesized by multiplying by b in the polar direction, and the three A transformer for determining an accident mode for obtaining a composite voltage (V _{aR + bS + cT} ) of the phase voltages of the first to third phases used to determine the accident mode of a short circuit accident of a phase AC circuit Then, the accident aspect determining means converts the voltage value and phase of the composite voltage input from the accident aspect determination transformer and the phase of the short-circuit current (I _Ry ) input from the two-phase through current transformer. Based on this, the accident aspect of the short circuit accident of the three-phase AC circuit may be determined.
The two-phase through current transformer (10) is installed in the transmission / distribution line, and any two phases of the transmission / distribution line are passed through the annular core of the two-phase through current transformer in different directions in different directions. And when the short circuit protection relay detects a short circuit accident based on the short circuit current (I _Ry ) input from the two-phase through current transformer, the first to third installed in each phase of the transmission and distribution line The overcurrent relay (4) which cuts off all the circuit breakers (2 _{1 to} 2 ₃ ) may be used.
The two-phase through current transformers are first and second two-phase through current transformers (10 ₁ , 10 ₂ ) installed on the primary side and the secondary side of the transformer (5), respectively, Arbitrary two phases on the primary side of the transformer are passed through the annular core of the first two-phase through current transformer in opposite directions for different times, and the annular core of the second two-phase through current transformer The arbitrary two phases on the secondary side of the transformer are penetrated through a different number of times in opposite directions, and the short circuit protection relay is connected to the short circuit current input from the first two-phase through current transformer and the When a short circuit fault is detected based on the difference current from the short circuit current input from the second two-phase through current transformer, the first to third circuit breakers installed in each phase on the primary side of the transformer (2 ₁ to 2 ₃₎ and the fourth to sixth breaker installed in each phase of the secondary side of the transformer (2 _{4-2 6)} and the current difference to collectively block the It may be a relay (20).
The two-phase through current transformers are first and second two-phase through current transformers (10 ₁ , 10 ₂ ) installed in the first and second transmission and distribution lines (1L, 2L), respectively. Arbitrary two phases of the first transmission / distribution line are passed through the annular iron core of the first two-phase through current transformer in different directions, and the annular of the second two-phase through current transformer The arbitrary two phases of the second power transmission / distribution line are passed through the iron core in opposite directions for a different number of times, and the short-circuit protection relay is a short-circuit current input from the first two-phase through current transformer When a short circuit fault is detected based on the sum current with the short circuit current input from the second two-phase through current transformer, the first to third circuit breakers installed in each phase of the first power transmission and distribution line (2 ₁ to 2 ₃₎ an over collectively cut off the fourth to sixth breaker installed in each phase of the second transmission and distribution lines and (2 _{4-2 6)} It may be a flow relay (30).
The two-phase through current transformers are first and second two-phase through current transformers (10 ₁ , 10 ₂ ) respectively installed on a power supply end bus side and a receiving end bus side of a transmission / distribution line, Any two phases of the transmission / distribution line are passed through the annular core of the first two-phase through current transformer in opposite directions for different times, and the feeding core is fed into the annular core of the second two-phase through current transformer. The arbitrary two phases of the distribution line are passed through in opposite directions a different number of times, and the short circuit protection relay detects the short circuit current detected by the first two phase through current transformer and the second two phase through transformer. When a short-circuit accident is detected based on a difference current from the short-circuit current detected by the flow device, _first to third circuit breakers (2 ₁ to 3) installed in each phase of the power transmission and distribution line on the power supply end bus side 2 ₃ ) and _fourth to sixth circuit breakers (2 ₄ to 2) installed in each phase of the power transmission and distribution line on the power receiving end bus side ₆ ) may be the first and second pulse code modulation current differential relays (60 ₁ , 60 ₂ ) that cut off all of them at once.
The two-phase through current transformer (10) is installed in the transmission / distribution line, and any two phases of the transmission / distribution line are passed through the annular core of the two-phase through current transformer in different directions in different directions. The short circuit protection relay calculates the short circuit current (I _Ry ) input from the two-phase through current transformer and the line voltage (V _RS , V _ST , V _TR ) of the transmission / distribution line. When a short-circuit accident is detected based on the voltage (V _Ry ), the overcurrent with voltage suppression that collectively shuts off the _first to _third circuit breakers (2 ₁ to 2 ₃ ) installed in each phase of the transmission and distribution line It may be a relay (50).

The two-phase through current transformer and the protective relay device of the present invention have the following effects.
(1) Current transformer and short-circuit protection to protect the three-phase AC circuit from short-circuit accidents by using a two-phase through current transformer that penetrates two phases of the three-phase AC circuit in opposite directions for different times The number of installed relays can be further reduced to reduce the equipment cost.
(2) Although the amplitude of the short-circuit current output from the two-phase through current transformer varies depending on the accident aspect of the short-circuit accident, the detection sensitivity of the short-circuit protection relay and the amplitude of the short-circuit protection relay can be adjusted or adjusted according to the accident aspect. The operating time can be the same.

  The above-mentioned purpose is achieved by using a two-phase through current transformer in which any two phases of a three-phase AC circuit are passed through the annular core wound with a secondary coil in opposite directions for different times. When a short-circuit accident was detected based on the short-circuit current input from the phase-through current transformer, it was realized by shutting off the circuit breakers installed in each phase of the three-phase AC circuit.

Embodiments of the two-phase through current transformer and the protective relay device of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the protective relay device according to the first embodiment of the present invention includes a two-phase through current transformer 10 installed in a transmission and distribution line and a short circuit input from the two-phase through current transformer 10. When a short circuit accident of the transmission and distribution line is detected based on the current I _Ry , the _first to _third circuit breakers 2 ₁ to 2 ₃ installed in the R phase, S phase, and T phase of the transmission and distribution line are collectively cut off. And an overcurrent relay 4.

Here, the two-phase through current transformer 10 is a through-type current transformer in which an R-phase and an S-phase of a power transmission / reception line are crossed in an opposite direction at an arbitrary angle through an annular core around which a secondary coil is wound. It is a vessel. That is, the R phase of the transmission / distribution line is penetrated in the polarity direction of the two-phase through current transformer 10 (direction from the first opening surface of the annular core to the second opening surface of the annular core). The S phase of the electric wire is penetrated in the opposite polarity direction (direction from the second opening surface of the annular core to the first opening surface of the annular core) of the two-phase through current transformer 10.
In addition, the R phase of the transmission / distribution line passes through the two-phase through current transformer 10 only once, but the S phase of the transmission / distribution line passes through the two-phase through current transformer 10 twice. Thereby, the two-phase through current transformer 10 outputs a difference current between a current flowing through the R phase of the transmission and distribution line and a current that is twice the current flowing through the S phase.

Therefore, when the load currents flowing in the R phase, S phase, and T phase of the transmission and distribution line when no short circuit accident has occurred are represented by I _R , I _S , and I _T , as shown in FIG. The phase load current I _R and the S phase load current I _S flow through the annular core of the two-phase through current transformer 10 in a reverse direction with a phase difference of 120 ° (that is, the R phase load current I _R Flows through the two-phase through current transformer 10 in the polarity direction, and the S-phase load current I _S flows through the two-phase through current transformer 10 in the opposite polarity direction). Therefore, the load current I input from the two-phase through current transformer 10 to the overcurrent relay 4 is a vector of the R-phase load current I _R and the current (= 2I _S ) obtained by doubling the S-phase load current I _S. As a result, the amplitude of the load current I is 7 ^1/2 times the amplitude of the R-phase load current I _R (S-phase load current I _S ).
I = I _R -2I _S
| I | = | I _R −2I _S |
= (| I _R | ² + | 2I _S | ² −2 × | I _R | × | 2I _S | × cos 120 °) ^1/2
= 7 ^1/2 × | I _R | (= 7 ^1/2 × | I _S |)

Also, when the short circuit current flowing in the R phase, S phase, and T phase of the transmission / distribution line is represented by I _FR , I _FS , I _FT when a short circuit accident occurs in the transmission / distribution line, the two-phase through current transformer 10 The short-circuit current I _Ry input to the overcurrent relay 4 is expressed as follows according to the accident aspect, where θ is the impedance angle of the short-circuit currents I _FR , I _FS , and I _FT .
(1) In the case of a short circuit accident between the R phase and the S phase When a short circuit accident between the R phase and the S phase occurs, the short circuit current I _FR of the R phase is generated in the R phase of the transmission and distribution line as shown by the broken arrow in FIG. flow inside direction, but the short-circuit current I _FS of S phase to the S phase of the transmission and distribution lines to flow to the outside direction, the T-phase of the transmission and distribution lines does not flow a short-circuit current I _FT T-phase.
Therefore, the short-circuit current I _Ry output from the two-phase through current transformer 10 to the overcurrent relay 4 is obtained by doubling the R-phase short-circuit current I _FR and the S-phase short-circuit current I _FS (= 2I _FS ). Although the vector difference is present, the phase difference between the R-phase short-circuit current I _FR and the S-phase short-circuit current I _FS is 180 °, and therefore the amplitude of the short-circuit current I _Ry is R-phase as shown in FIG. This is three times the amplitude of the short-circuit current I _FR (S-phase short-circuit current I _FS ).
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR −2I _FS | = 3 × | I _FR | (= 3 × | I _FS |)
In FIGS. 3 and 4, short-circuit currents I _FR , I _FS , I _FT flowing in the inner direction of the transmission / distribution line are solid arrows, and short-circuit currents I _FR , I _FS , I _FT is indicated by a dashed-dotted arrow.
(2) In the case of a short circuit accident between the S phase and the T phase When a short circuit accident occurs between the S phase and the T phase, the short circuit current I _FS of the S phase is generated in the S phase of the power transmission and distribution line as shown by the broken arrow in FIG. flow inside direction, but the short-circuit current I _FT T-phase to the T phase of the transmission and distribution lines to flow to the outside direction, the R-phase of the transmission and distribution lines does not flow a short-circuit current I _FR of R-phase.
Therefore, the short-circuit current I _Ry output from the two-phase through current transformer 10 to the overcurrent relay 4 is obtained by reversing the polarity of the current that is twice the S-phase short-circuit current I _FS (= −2I _FS ). The amplitude of the current I _Ry is twice the amplitude of the S-phase short-circuit current I _FS as shown in FIG.
I _Ry = -2I _FS
| I _Ry | = 2 × | I _FS |
(3) In the case of a short circuit accident between the T phase and the R phase When a short circuit accident occurs between the T phase and the R phase, the short circuit current I _FT of the T phase is applied to the T phase of the transmission and distribution line as shown by the broken arrow in FIG. flow inside direction, but the short-circuit current I _FR of R-phase to R-phase of transmission and distribution lines to flow to the outside direction, the S-phase of the transmission and distribution lines does not flow a short-circuit current I _FS of S phase.
Thus, two-phase through the short-circuit current I _Ry outputted from the current transformer 10 to the overcurrent relay 4 short-circuit current I _FR next to R-phase, the amplitude of the short-circuit current I _Ry is R-phase as shown in FIG. 4 (a) The amplitude of the short-circuit current _{IFR is} as follows.
I _Ry = I _{FR
| I Ry | = | I FR} |
(4) In the case of a short circuit accident between R phase, S phase, and T phase When a short circuit accident between R phase, S phase, and T phase occurs, the R phase and S phase of the power transmission and distribution line as shown by the dashed arrows in FIG. In addition, an R-phase short-circuit current I _FR , an S-phase short-circuit current I _FS, and a T-phase short-circuit current I _FT flow in the internal direction with a phase difference of 120 °, respectively.
Therefore, the short-circuit current I _Ry output from the two-phase through current transformer 10 to the overcurrent relay 4 is obtained by doubling the R-phase short-circuit current I _FR and the S-phase short-circuit current I _FS (= 2I _FS ). The phase difference between the R-phase short-circuit current I _FR and the S-phase short-circuit current I _FS is 120 °, and the amplitude of the short-circuit current I _F1 is R-phase as shown in FIG. The short-circuit current I _FR (S-phase short-circuit current I _FS ) is 7 ^1/2 times the amplitude.
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR -2I _FS |
= (| I _FR | ² + | 2I _FS | ² -2 × | I _FR | × | 2I _FS | × cos 120 °) ^1/2
= 7 ^1/2 × | I _FR | (= 7 ^1/2 × | I _FS |)

When the amplitude of the short circuit current I _Ry exceeds the current set value, the overcurrent relay 4 determines that a short circuit accident has occurred in the transmission and distribution lines, and the _first to _third circuit breakers 2 ₁ to 2 _3. Block all at once.

  The two-phase through-current transformer 10 penetrates the R phase of the transmission / distribution line once and the S phase twice, but penetrates the S phase of the transmission / distribution line once and the T phase twice. It may be penetrated, or the T phase of the transmission / distribution line may be penetrated once and the R phase may be penetrated twice.

Next, a protective relay device according to a second embodiment of the present invention will be described with reference to FIG.
Protective relay apparatus according to this embodiment installed, as shown in FIG. 9, the first two-phase through current transformer 10 ₁ installed on the primary side of the transformer 5, the secondary side of the transformer 5 Second two-phase through current transformer 10 ₂ , short-circuit current input from first two-phase through current transformer 10 _1, and short-circuit current input from second two-phase through current transformer 10 _{2 Is} detected in the R phase, S phase, and T phase on the primary side of the transformer 5 when a short circuit accident inside the transformer 5 is detected based on the difference current (hereinafter referred to as “short circuit current I _Ry ”). First to third circuit breakers 2 ₁ to 2 ₃ and _fourth to _sixth circuit breakers 2 ₄ to 2 ₆ installed in the R-phase, S-phase, and T-phase on the secondary side of the transformer 5, respectively. And a current differential relay 20 that collectively cuts off the power.

Here, the first two-phase through current transformer 10 ₁ crosses the R-phase and S-phase on the primary side of the transformer 5 in an opposite direction and at an arbitrary angle with an annular core wound with a secondary coil. Through-type current transformer. That is, the primary side of the R-phase transformer 5 is through the first two-phase through polarity direction of the current transformer 10 _1, S-phase of the primary side of the transformer 5 is first two-phase It is penetrated in the opposite polarity direction of the through current transformer 10 _1.
Further, the primary side of the R-phase transformer 5 is through only the first two-phase through current transformer 10 ₁ once, the higher the primary side of the S-phase two transformers 5 1 It extends through the two-phase through current transformer 10 _1. Thus, from the first two-phase through current transformer 10 _1, the difference current between the current obtained by doubling the current flowing through the current and the S-phase flowing in the primary side of the R-phase transformer 5 is output.
Similarly, the second two-phase through current transformer 10 ₂ crosses the R-phase and S-phase on the secondary side of the transformer 5 in an opposite direction and at an arbitrary angle with an annular core wound with a secondary coil. Through-type current transformer. That is, the secondary side of the R-phase transformer 5 is through a second two-phase through current transformer 10 _second polarity direction, S-phase of the secondary side of the transformer 5 and the second two-phase It is penetrated in the opposite polarity direction of the through current transformer 10 _2.
Further, the transformer secondary side of the R phase 5 extends through only the second two-phase through current transformer 10 ₂ 1 times, the transformer secondary side of the 5 S phase about 2 times the second It extends through the two-phase through current transformer 10 _2. Thus, the second of two phases through the current transformer 10 _2, differential current between twice the current the current through the current and S phase through the secondary side of the R-phase transformer 5 is output.
Further, the second two-phase through current transformer 10 ₂ has the first two-phase through current transformer in which the polarity of the short-circuit current input from the second two-phase through current transformer 10 ₂ to the current differential relay 20 is the same. as a polarity opposite to the short-circuit current which is input to the current differential relay 20 from 10 ₁ is connected to a current differential relay 20.

Therefore, the primary load currents flowing in the R-phase, S-phase, and T-phase on the primary side (transmission end) of the transformer 5 when no short-circuit accident has occurred are represented by I _1R , I _1S , I _1T R-phase secondary side of the vessel 5 (receiving end), S phase and the secondary load current flowing to the T-phase I _2R, I _2S, expressed in I _2T, 1 of R-phase primary load current I _1R and S phase The primary load current I _1S of the first two-phase through current transformer 10 ₁ flows in the opposite direction with a phase difference of 120 ° (that is, the R-phase primary load current I _1R is The first two-phase through current transformer 10 ₁ flows through in the polarity direction, and the S-phase primary load current I _1S flows through the first two-phase through current transformer 10 ₁ in the opposite polarity direction. .). Therefore, the primary load current i ₁ input from the first two-phase through current transformer 10 ₁ to the current differential relay 20 is the same as in the overcurrent relay 4 according to the first embodiment described above. The vector difference between the R-phase primary load current I _1R and the current obtained by doubling the S-phase primary load current I _1S (= 2I _1S ) is the amplitude of the primary load current i _1. It becomes 7 ^1/2 times the amplitude of the current I _1R (S-phase primary load current I _1S ) (see FIG. 2A).
i ₁ = I _1R -2I _1S
| I ₁ | = | I _1R −2I _1S | = 7 ^1/2 × | I _1R | (= 7 ^1/2 × | I _1S |)
Similarly, a second secondary load current of the secondary phase through current transformer 10 ₂ secondary load current i ₂ that is input to the current differential relay 20 from the R-phase I _2R and S phases of the secondary load current I _2S Is the vector difference (polarity is negative) from the current that is twice the current (= 2I _2S ), and the amplitude of the secondary load current i ₂ is the R-phase secondary load current I _2R (S-phase secondary load current I _2S ) consisting of a ^71/2 times the amplitude (see FIG. 2 (a)).
_{i 2 = - (I 2R -2I} 2S)
| I ₂ | = | I _2R −2I _2S | = 7 ^1/2 × | I _2R | (= 7 ^1/2 × | I _2S |)
As a result, the load current I input to the current differential relay 20 is represented by a vector sum of the primary load current i ₁ and the secondary load current i _2, and the amplitude of the load current I is “0” (| I | = | I ₁ + i ₂ | = 0).

Further, for example, when a short circuit accident occurs on the primary side inside the transformer 5, short circuit currents flowing in the R phase, S phase, and T phase of the primary transmission and distribution line of the transformer 5 are represented by I _FR , I _FS , When expressed by I _FT , the short-circuit current I _Ry (the difference current between the short-circuit current input from the first two-phase through current transformer 10 ₁ and the short-circuit current input from the second two-phase through current transformer 10 ₂ ) Is expressed as follows according to the accident aspect in the same manner as in the overcurrent relay 4 according to the first embodiment described above.
(1) In case of short-circuit accident between R phase and S phase (see Fig. 3 (a))
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR −2I _FS | = 3 × | I _FR | (= 3 × | I _FS |)
(2) In the case of a short circuit accident between the S phase and the T phase (see FIG. 3B)
I _Ry = -2I _FS
| I _Ry | = 2 × | I _FS |
(3) In the case of a short circuit accident between T phase and R phase (see Fig. 4 (a))
I _Ry = I _{FR
| I Ry | = | I FR} |
(4) In the case of a short circuit accident between R phase, S phase, and T phase (see FIG. 4B)
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR −2I _FS | = 7 ^1/2 × | I _FR | (= 7 ^1/2 × | I _FS |)

Current differential relay 20, when the amplitude of the short-circuit current I _Ry exceeds the current setting value, it is determined that the short-circuit failure occurs inside the transformer 5, the circuit breaker 2 ₁ of the first to sixth Block ₆ and ₆ together.

Although the first two-phase through current transformer 10 ₁ is passed through the S-phase 2 times with pass through once the primary side of the R-phase transformer 5, the primary side of the transformer 5 S The phase may be penetrated once and the T phase may be penetrated twice, or the primary side T phase of the transformer 5 may be penetrated once and the R phase may be penetrated twice.
The same applies to the second two-phase through current transformer 10 ₂ .

Next, a protective relay device according to a third embodiment of the present invention will be described with reference to FIG.
The protection relay device according to the present embodiment is a power reception protection relay device for protecting the first and second transmission / distribution lines 1L and 2L from a short circuit accident in the premises. As shown in FIG. the first two-phase through current transformer 10 ₁ installed on the transmission and distribution lines 1L, second two-phase through current transformer 10 ₂ installed in the second transmission and distribution lines 2L, a first two-phase Based on the sum of the short-circuit current input from the through-current transformer 10 ₁ and the short-circuit current input from the second two-phase through-current transformer 10 ₂ (hereinafter referred to as “short-circuit current I _Ry ”). When a short circuit accident is detected on the premises, the _first to _third circuit breakers 2 ₁ to 2 ₃ and the second transmission and distribution lines respectively installed in the R phase, S phase and T phase of the first transmission and distribution line 1L An overcurrent relay 30 that collectively shuts off the _fourth to _sixth circuit breakers 2 ₄ to 2 ₆ installed in the 2 L R phase, S phase, and T phase, respectively. It has.

Here, the first two-phase through current transformer 10 _1, are crossed at any angle and the R-phase and S-phase of the first transmission and distribution lines 1L in opposite directions annular core formed by winding a secondary coil Through-type current transformer. Ie, R-phase of the first transmission and distribution lines 1L is through the first two-phase through polarity direction of the current transformer 10 ₁ but, S-phase of the first transmission and distribution lines 1L first two-phase It is penetrated in the opposite polarity direction of the through current transformer 10 _1.
In addition, R-phase of the first transmission and distribution lines 1L is through only the first two-phase through current transformer 10 ₁ once but, S-phase of the first transmission and distribution lines 1L is about twice the first It extends through the two-phase through current transformer 10 _1. Thus, from the first two-phase through current transformer 10 _1, the difference current between the first current obtained by doubling the current flowing through the current and the S phase through the R-phase of the transmission and distribution lines 1L is outputted.
Similarly, the second two-phase through current transformer 10 ₂ crosses the R phase and S phase of the second power transmission and distribution line 2L in opposite directions and at an arbitrary angle on the annular core wound with the secondary coil. Through-type current transformer. Ie, R-phase of the second transmission and distribution lines 2L is through the second two-phase through current transformer 10 _second polarity direction but, S-phase of the second transmission and distribution lines 2L second two-phase It is penetrated in the opposite polarity direction of the through current transformer 10 _2.
In addition, R-phase of the second transmission and distribution lines 2L is through only the second two-phase through current transformer 10 ₂ once, but, S-phase of the second transmission and distribution lines 2L is about twice the second It extends through the two-phase through current transformer 10 _2. Thus, from the second two-phase through current transformer _102, the difference current between the second transmission and distribution lines 2L current obtained by doubling the current flowing through the current and the S phase through the R-phase are output.

Therefore, the load current I input from the first and second two-phase through current transformers 10 ₁ and 10 ₂ to the overcurrent relay 30 when no short circuit accident occurs on the premises is the first implementation described above. As in the case of the overcurrent relay 4 according to the example, the vector difference between the R-phase load current I _R and the current obtained by doubling the S-phase load current I _S (= 2I _S ), and the amplitude of the load current I is This is ^71/2 times the amplitude of the R-phase load current I _R (S-phase load current I _S ) (see FIG. 2A).
I = I _R -2I _S
| I | = | I _R −2I _S | = 7 ^1/2 × | I _R | (= 7 ^1/2 × | I _S |)

In addition, when a short-circuit accident occurs on the premises, the short-circuit currents flowing in the R-phase, S-phase, and T-phase of the first and second power transmission lines 1L, 2L are expressed as I _FR , I _FS , I _FT The current I _Ry (the sum of the short-circuit current input from the first two-phase through current transformer 10 ₁ and the short-circuit current input from the second two-phase through current transformer 10 ₂ ) is the above-described first current. Similarly to the case of the overcurrent relay 4 according to the embodiment, it is expressed as follows according to the accident aspect.
(1) In case of short-circuit accident between R phase and S phase (see Fig. 3 (a))
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR −2I _FS | = 3 × | I _FR | (= 3 × | I _FS |)
(2) In the case of a short circuit accident between the S phase and the T phase (see FIG. 3B)
I _Ry = -2I _FS
| I _Ry | = 2 × | I _FS |
(3) In the case of a short circuit accident between T phase and R phase (see Fig. 4 (a))
I _Ry = I _{FR
| I Ry | = | I FR} |
(4) In the case of a short circuit accident between R phase, S phase, and T phase (see FIG. 4B)
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR −2I _FS | = 7 ^1/2 × | I _FR | (= 7 ^1/2 × | I _FS |)

When the amplitude of the short-circuit current _IRy exceeds the current set value, the overcurrent relay 30 determines that a short-circuit accident has occurred in the premises and collects the _first to _sixth circuit breakers 2 ₁ to 2 ₆ at _once. Cut off.

Note that the first two-phase through current transformer 10 ₁ was passed through the S-phase 2 times with pass through once R-phase of the first transmission and distribution lines 1L, S of the first transmission and distribution lines 1L The phase may be penetrated once and the T phase may be penetrated twice, or the T phase of the first power distribution line 1L may be penetrated once and the R phase may be penetrated twice.
The same applies to the second two-phase through current transformer 10 ₂ .

Next, a protective relay device according to a fourth embodiment of the present invention will be described with reference to FIG.
Protective relay apparatus according to this embodiment, as shown in FIG. 11, the first two-phase through the current transformer 10 _1, the receiving end bus side of the transmission and distribution lines installed in the electric transmission of power terminal bus side Of the second two-phase through current transformer 10 ₂ installed in the first two-phase through current transformer 10 ₁ and the second short-circuit current from the second two-phase current transformer 10 ₂ . When a short-circuit accident in the transmission / distribution line is detected based on the difference current (hereinafter referred to as “short-circuit current I _Ry ”), it is installed in the R-phase, S-phase, and T-phase of the transmission / distribution line on the power supply end bus side. First to _third circuit breakers 2 ₁ to 2 ₃ and _fourth to _sixth circuit breakers 2 ₄ to 2 ₆ respectively installed in the R-phase, S-phase, and T-phase of the power transmission and distribution line on the receiving end bus side; 1 and second pulse code modulation current differential relays 60 ₁ and 60 ₂ (hereinafter referred to as “first and second PCM current differential relays”). Vessels 60 _1, referred to as 60 _2. "); And a.
Note that the first and second PCM current differential relays 60 ₁ and 60 ₂ transmit and receive a short-circuit current via a communication network.

Here, the first two-phase through current transformer 10 ₁ was passed through by cross-R-phase and S-phase of the transmission and distribution lines to the annular core formed by winding a secondary coil at any angle and in the opposite direction It is a through-type current transformer. Ie, R-phase of the electric transmission has been through the first two-phase through polarity direction of the current transformer 10 _1, S-phase of the electric transmission first two-phase through current transformer 10 ₁ anti It penetrates in the polar direction.
In addition, R-phase of the electric transmission is through only the first two-phase through current transformer 10 ₁ once but, S-phase of the electric transmission about twice the first two-phase through current transformer 10 ₁ is penetrated. Thus, from the first two-phase through current transformer 10 _1, the difference current between the current obtained by doubling the current flowing through the current and the S phase through the R-phase of the transmission and distribution lines are output.
Similarly, the second two-phase through current transformer 10 ₂ was passed through by cross-R-phase and S-phase of the transmission and distribution lines to the annular core formed by winding a secondary coil at any angle and in the opposite direction It is a through-type current transformer. Ie, R-phase of the electric transmission has been through the second two-phase through current transformer 10 _second polarity direction, S-phase of the electric transmission a second two-phase through current transformer 10 ₂ anti It penetrates in the polar direction.
In addition, R-phase of the electric transmission is through only the second two-phase through current transformer 10 ₂ 1 times, the transmission and distribution lines S phase about twice a second two-phase through current transformer 10 ₂ has been penetrated. Thus, from the second two-phase through current transformer _102, a differential current between the current obtained by doubling the current flowing through the current and the S phase through the R-phase of the transmission and distribution lines are output.
Furthermore, the second two-phase through current transformer 10 ₂ has the first two-phase through current transformer 10 ₂ having a first short-circuit current polarity that is input to the second PCM current differential relay 60 _2. a phase through current transformer 10 ₁ so as to be opposite to the polarity of the first PCM current short-circuit current which is input to the differential relay 60 ₁ is connected to a second PCM current differential relay 60 _2.

Therefore, the transmission end load current flowing in the R phase, S phase, and T phase of the transmission end of the transmission / distribution line when no short circuit accident has occurred in the transmission / distribution line is expressed as I _aR , I _aS , I _aT. When the receiving end load currents flowing in the R phase, S phase, and T phase at the receiving end of the _wire are expressed by I _bR , I _bS , I _bT , the R phase transmission end load current I _aR and the S phase transmission end load current I the _aS flows through the first two-phase through current transformer 10 _first annular core in the opposite direction with a phase difference of 120 ° (i.e., the sending end load current I _aR of R-phase first two-phase through The current flows through the current transformer 10 ₁ in the polarity direction, and the S-phase power transmission end load current I _aS flows through the first two-phase through current transformer 10 ₁ in the opposite polarity direction).
Therefore, the sending end load current I _a supplied from the first two-phase through current transformer 10 ₁ to the first PCM current differential relay 60 _1, when the overcurrent relay 4 according to the first embodiment described above In the same manner, the vector difference between the R-phase transmission end load current I _aR and the current (= 2I _aS ) that is twice the S-phase transmission end load current I _aS, and the amplitude of the transmission end load current I _a is R It becomes 7 ^1/2 times the amplitude of the phase transmission end load current I _aR (S phase transmission end load current I _aS ) (see FIG. 2A).
I _a = I _aR -2I _aS
| I _a | = | I _aR −2I _aS | = 7 ^1/2 × | I _aR | (= 7 ^1/2 × | I _aS |)
Similarly, the receiving end load current I _b input from the second two-phase through current transformer 10 ₂ to the second PCM current differential relay 60 ₂ is the R-phase receiving end load current I _bR and the S-phase receiving current I _bR . The vector difference (the polarity is negative) from the current obtained by doubling the receiving end load current I _bS (= 2I _bS ), and the amplitude of the receiving end load current I _b is the R phase receiving end load current I _bR (S phase receiving) 7 ^1/2 times the amplitude of the end load current I _bS ).
I _b = − (I _bR −2I _bS )
| I _b | = | I _bR −2I _bS | = 7 ^1/2 × | I _bR | (= 7 ^1/2 × | I _bS |)
As a result, the load current I input to the first and second PCM current differential relays 60 ₁ and 60 ₂ is expressed as a vector sum of the transmission end load current I _a and the reception end load current I _b, and the load The amplitude of the current I is “0” (| I | = | I _a + I _b | = 0).

Moreover, when the short-circuit current that flows in the R-phase, S-phase, and T-phase of the transmission / distribution line is expressed by I _FR , I _FS , I _FT when a short-circuit accident occurs in the transmission / distribution line, the short-circuit current I _Ry (first The difference between the short-circuit current from the two-phase through current transformer 10 ₁ and the short-circuit current from the second two-phase through current transformer 10 ₂ ) is the same as that in the overcurrent relay 4 according to the first embodiment described above. Similarly, it is expressed as follows according to the accident aspect.
(1) In case of short-circuit accident between R phase and S phase (see Fig. 3 (a))
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR −2I _FS | = 3 × | I _FR | (= 3 × | I _FS |)
(2) In the case of a short circuit accident between the S phase and the T phase (see FIG. 3B)
I _Ry = -2I _FS
| I _Ry | = 2 × | I _FS |
(3) In the case of a short circuit accident between T phase and R phase (see Fig. 4 (a))
I _Ry = I _{FR
| I Ry | = | I FR} |
(4) In the case of a short circuit accident between R phase, S phase, and T phase (see FIG. 4B)
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR −2I _FS | = 7 ^1/2 × | I _FR | (= 7 ^1/2 × | I _FS |)

The first and second PCM current differential relays 60 ₁ and 60 ₂ determine that a short-circuit accident has occurred in the transmission and distribution line when the amplitude of the short-circuit current I _Ry exceeds the current settling value. The 1st to 6th circuit breakers 2 ₁ to 2 ₆ are collectively cut off.

Incidentally, with Although the first two-phase through current transformer 10 ₁ is passed through twice S phase causes penetrate once R-phase of transmission and distribution lines, to penetrate once S phase of transmission and distribution lines T The phase may be penetrated twice, or the T phase of the transmission and distribution line may be penetrated once and the R phase may be penetrated twice.
The same applies to the second two-phase through current transformer 10 ₂ .

As described above, in the first to fourth embodiments, by using a two-phase through current transformer (such as the two-phase through current transformer 10 shown in FIG. 1), a current transformer and a short-circuit protective relay ( Although the number of installed overcurrent relays 4 shown in FIG. 1 can be further reduced, as described above, the amplitude of the load current I is ^71/2 times and a short circuit accident between the R phase and the S phase. short-circuit current I amplitude of _Ry is three times the amplitude of the short-circuit current I _Ry in short circuit of the T-phase -R phase, amplitude T phase -R phase of the short-circuit current I _Ry in short circuit of the S-phase -T phase in doubling of the amplitude of the short-circuit current I _Ry in short circuit of, also, short amplitude of the short-circuit current I _Ry in short circuit of the R-phase -S phase -T phase is in a short circuit accident T phase -R phase current I _Ry Is 7 ^1/2 times the amplitude of. Therefore, the detection sensitivity and operating time of the short circuit protection relay cannot be made the same for all accident aspects.

Therefore, the accident aspect is determined using any of the following first to fifth accident aspect determination methods, and the short-circuit current from the two-phase through current transformer is multiplied by 1 according to the accident aspect determination result. You may provide the arithmetic processing part made into 3 times, ^1/2 times, or 1/7 ^1/2 times between a two-phase through current transformer and a short circuit protection relay, or in a short circuit protection relay.

(First accident mode judgment method)
The accident aspect is determined based on the three line voltages, the three phase voltages, or the phase / line voltage (combination of the phase voltage and the line voltage).

Table 1 shows the accident condition determination conditions based on the three line voltages. In addition, ○ mark indicates the line voltage in which the voltage drop is detected based on the voltage information from the undervoltage relay installed on the bus, and the X mark is based on the voltage information from this undervoltage relay. The line voltage in which no voltage drop was detected is shown (the voltage drop detection sensitivity is about 75 to 80% of the rated voltage).

Table 2 shows the accident condition determination conditions based on the three phase voltages. In addition, a circle indicates a phase voltage in which a voltage drop is detected based on voltage information from an undervoltage relay installed on the bus, and a cross indicates a voltage based on voltage information from the undervoltage relay. The phase voltage in which no decrease was detected is indicated (the voltage drop detection sensitivity is about 75 to 80% of the rated voltage).

Table 3 shows the accident condition judgment conditions based on the phase / line voltage. The circles indicate the phase voltage and line voltage at which a voltage drop is detected based on the voltage information from the undervoltage relay installed on the bus, and the x indicates voltage information from the undervoltage relay. The phase voltage and the line voltage in which no voltage drop was detected based on the above are shown (voltage drop detection sensitivity is about 75 to 80% of the rated voltage).

(Second accident mode judgment method)
The accident aspect is determined based on the voltage value and phase of one line voltage and one phase voltage.

For example, based on the fact that the phase of the line voltage V _TR between the T phase and the R phase is 210 ° and the phase of the phase voltage V _R of the _R phase is 0 ° (see FIG. 2B), the transmission and distribution lines The R-phase-S phase line voltage V _RS at the time of the short-circuit accident between the R-phase and S-phase and the S-phase-T-phase line voltage V _ST at the time of the short-circuit accident between the S-phase and the T-phase 85V, it is determined that a short-circuit accident has occurred on the condition that the line voltage V _TR between the T phase and the R phase is equal to or lower than a predetermined first voltage value k1 = 85 V, and the line between the T phase and the R phase The voltage V _TR is equal to or lower than a predetermined second voltage value k2 = 104.3 V, and the phase of the line voltage V _TR between the T phase and the R phase before the short circuit accident is 210 ° as a reference. the T-phase -R phase of the phase of the line voltage V _TR is advanced or delayed by a predetermined angular range α (5.95 ° ≦ α ≦ 30 ° or -30 ° α ≦ -5.95 °) determining a short-circuit failure condition has occurred (the following (1-1) and (1-2) refer to formula).
V _TR ≦ [{(110/3 ^1/2 ) × 1.5} ² + (85/2) ² ] ^1/2
≦ (95.26 ² +42.5 ² ) ^1/2
≦ 104.3 (V) (1-1)
α ≧ 30 ° -tan ⁻¹ (42.5 / 95.26)
≧ 5.95 (°) (1-2)

Moreover, the accident aspect is determined as follows.
(1) In the case of a short-circuit accident between the R phase and the S phase The line voltage V _TR between the T phase and the R phase is 104.3 V or less, and the line voltage V _TR between the T phase and the R phase before the short circuit accident is When the phase of the line voltage V _TR between the T phase and the R phase is delayed by an angle range α (+ α) with respect to the phase = 210 ° as a reference, it is determined that the short-circuit accident occurs between the R phase and the S phase (FIG. 12 ( a)).
(2) In the case of a short circuit accident between the S phase and the T phase The line voltage V _TR between the T phase and the R phase is 104.3 V or less, and the line voltage V _TR between the T phase and the R phase before the short circuit accident is When the phase of the line voltage V _TR between the T phase and the R phase is advanced only within the angle range α (−α) with respect to the phase = 210 ° as a reference, it is determined that a short circuit accident between the S phase and the T phase occurs (FIG. (See (b)).
(3) In the case of a short circuit accident between the T phase and the R phase The line voltage V _TR between the T phase and the R phase is 85 V or less, and the phase of the line voltage V _TR between the T phase and the R phase before the short circuit accident = The phase of the line voltage V _TR between the T phase and the R phase is not delayed or advanced by an angle range α with respect to 210 ° (that is, greater than −5.95 ° and 5.95 °). And the phase of the R-phase phase voltage V _R before the short circuit accident is 0 ° as a reference, and the phase of the R-phase phase voltage V _R has a predetermined other angle range β (6.76 ° ≦ β ≦ 60 °, see (Equation 1-3)) (−β), it is determined that there is a short circuit accident between the T phase and the R phase (see FIG. 12C).
β ≧ 60 ° -tan ⁻¹ [42.5 / {110 / (2 × 3 ^1/2 )}]
≧ 6.76 (°) (1-3)
(4) In the case of a short circuit accident between R phase, S phase and T phase The line voltage V _TR between T phase and R phase is 85V or less, and the line voltage V _TR between T phase and R phase before the short circuit accident. The phase of the line voltage V _TR between the T-phase and the R-phase is not delayed or advanced by the angle range α with respect to the phase of 210 = 210 ° (that is, greater than −5.95 ° and 5 .. is smaller than .95 °), and the phase of the R phase voltage V _R before the short-circuit accident is 0 ° or the phase of the R phase voltage V _R is delayed or advanced by another angle range β. It is determined that a short-circuit accident between the R phase, the S phase, and the T phase is performed on the condition that the phase is not larger (that is, larger than −6.76 ° and smaller than 6.76 °) (FIG. 12D). reference).

Although the T-phase-R phase line voltage V _TR and the R-phase phase voltage V _R are used, any one of the voltage combinations indicated by circles in Table 4 may be used. However, it is necessary to change the short-circuit accident occurrence determination condition and the accident aspect determination condition described above according to the combination of voltages.

(Third accident mode determination method)
The accident aspect is determined based on the voltage value and phase of one line voltage and the phase of the short-circuit current _IRy input from the two-phase through current transformer.

For example, with reference to the phase of the T-phase to R-phase line voltage V _TR being 210 °, the R-phase to S-phase line voltage V _RS at the time of a short-circuit fault between the R-phase and S-phase of the transmission and distribution line and S phase -T When the line voltage V _ST between phases S phase -T phase when a short circuit accident and 85V of short-circuit failure detection sensitivity, a first voltage line voltage V _TR of the T-phase -R phase is given It is determined that a short-circuit accident has occurred on condition that the value k1 = 85 V or less, and the T-phase to R-phase line voltage V _TR is a predetermined second voltage value k2 = 104.3 V or less, and The phase of the line voltage V _TR between the T phase and the R phase before the short circuit accident = 210 ° as a reference, the phase of the line voltage V _TR between the T phase and the R phase at the time of the short circuit accident is delayed by a predetermined angle range α. A short-circuit accident occurs on the condition that it is moving or advanced (5.95 ° ≦ α ≦ 30 ° or −30 ° ≦ α ≦ −5.95 °) A constant ((1-1) see formula and (1-2) below).

Moreover, the accident aspect is determined as follows.
(1) In the case of a short-circuit accident between the R phase and the S phase The line voltage V _TR between the T phase and the R phase is 104.3 V or less, and the line voltage V _TR between the T phase and the R phase before the short circuit accident is When the phase of the line voltage V _TR between the T phase and the R phase is delayed by an angle range α (+ α) with respect to the phase = 210 ° as a reference, it is determined that the short-circuit accident occurs between the R phase and the S phase (FIG. 13 ( a)).
(2) In the case of a short circuit accident between the S phase and the T phase The line voltage V _TR between the T phase and the R phase is 104.3 V or less, and the line voltage V _TR between the T phase and the R phase before the short circuit accident is When the phase of the line voltage V _TR between the T phase and the R phase is advanced only within the angle range α (−α) with respect to the phase = 210 ° as a reference, it is determined that a short circuit accident between the S phase and the T phase occurs (FIG. 13). (See (b)).
(3) In the case of a short circuit accident between the T phase and the R phase The line voltage V _TR between the T phase and the R phase is 85 V or less, and the phase of the line voltage V _TR between the T phase and the R phase before the short circuit accident = The phase of the line voltage V _TR between the T phase and the R phase is not delayed or advanced by an angle range α with respect to 210 ° (that is, greater than −5.95 ° and 5.95 °). And the phase of the short-circuit current I _Ry is determined in consideration of arc resistance and the like with a predetermined first angle range γ (−150 ° ≦ γ ≦ −90 °, γ is an impedance angle θ = 75 °) If it is within the range, it is determined that there is a short circuit accident between the T phase and the R phase (see FIG. 13C).
(4) In the case of a short circuit accident between R phase, S phase and T phase The line voltage V _TR between T phase and R phase is 85V or less, and the line voltage V _TR between T phase and R phase before the short circuit accident. The phase of the line voltage V _TR between the T-phase and the R-phase is not delayed or advanced by the angle range α with respect to the phase of 210 = 210 ° (that is, greater than −5.95 ° and 5 Less than .95 °) and the phase of the short-circuit current I _Ry is a predetermined second angle range δ (139.1 ° ≦ δ ≦ 199.1 °, where δ is an impedance angle θ = 75 ° and arc resistance, etc. If it is within the range, it is determined that there is a short-circuit accident between the R phase, the S phase, and the T phase (see FIG. 13D).

(Fourth accident mode determination method)
Accident aspects determination transformer 110 shown in FIG. 14 (accident appearance determination transformer according to a first embodiment of the present invention) is placed to the bus, composite voltage output from the accident aspect determination transformer 110 V _{RS- Based on} the voltage value and phase of _2T and the phase of the short-circuit current I _Ry , the accident aspect is determined as follows.
Here, the secondary side of the accident phase determination transformer 110 sets the phase voltage V _R of the R phase in the polarity direction, the phase voltage V _S of the S phase in the opposite polarity direction, and the phase voltage V _T of the T phase in the opposite direction. The wires are wired so as to be doubled in the polarity direction. As a result, the composite voltage V _RS-2T output from the accident aspect determination transformer 110 is expressed by the following equation.
V _RS-2T = V _R -V _S -2V _T
Further, although the impedance angle θ is usually 75 °, the phase angle of the short-circuit current I _Ry takes into consideration the arc resistance, from 30 ° (−45 °) to 90 ° (+ 15 °) which is the maximum angle at the time of a short-circuit accident. ).

(1) In the case of a short-circuit accident between the R phase and the S phase The voltage value of the composite voltage V _RS-2T is a predetermined first composite voltage value K ₁ = 100.1 V or less (see equation (2-1)). In addition, the phase of the composite voltage V _RS-2T at the time of the short-circuit accident is set to a predetermined first composite voltage angle range ε ₁ (7 based on the fact that the phase of the composite voltage V _RS-2T at the normal time is 19.1 °. .10 ° (= X ₁ ) ≦ ε ₁ ≦ 40.9 ° (= X ₂ ) (Refer to equations (2-2) and (2-3)) (+ ε ₁ ) and short circuit When the phase of the current I _Ry is within a predetermined first short-circuit current angle range λ ₁ (−19.1 ° ≦ λ ₁ ≦ 40.9 °), it is determined that a short-circuit accident between the R phase and the S phase occurs.
K ₁ = [(83.15) ² + (72.01 × 85/110) ² ] ^1/2
= 100.1 (V) (2-1)
^{_{X 1 = cos -1 (83.15 /}} 110.0) -cos -1 (83.15 / 100.05)
= 7.10 (°) (2-2)
X ₂ = 60-19.1
= 40.9 (°) (2-3)
(2) In the case of a short circuit accident between the S phase and the T phase The voltage value of the composite voltage V _RS-2T is a predetermined second composite voltage value K ₂ = 107.6 V or less (see the formula (2-4)), In addition, the phase of the composite voltage V _RS-2T at the time of the short-circuit accident is determined to be a predetermined second composite voltage angle range ε ₂ (4 based on the phase of the composite voltage V _RS-2T at the normal time being 19.1 °. .12 ° (= X ₃ ) ≦ ε ₂ ≦ 19.1 ° (= X ₄ ) (see formulas (2-5) and (2-6)) (−ε ₂ ) When the phase of the short-circuit current I _Ry is advanced only within a predetermined second short-circuit current angle range λ ₂ (19.1 ° ≦ λ ₂ ≦ 79.1 °) (−λ ₂ ), between the S phase and the T phase Judged as a short circuit accident.
K ₂ = [(103.94) ² + (36.01 × 85/110) ² ] ^1/2
= 107.6 (V) (2-4)
X ₃ = cos ⁻¹ (103.94 / 110) −cos ⁻¹ (103.94 / 107.60)
= 4.12 (°) (2-5)
X ₄ = 19.1-0
= 19.1 (°) (2-6)
(3) In the case of a short-circuit accident between the T phase and the R phase The voltage value of the composite voltage V _RS-2T is equal to or less than a predetermined third composite voltage value K ₃ = 86.0 V (see formula (2-7)) Further, the phase of the composite voltage V _RS-2T at the time of a short-circuit accident is determined to be a predetermined third composite voltage angle range ε ₃ (3 based on the phase of the composite voltage V _RS-2T at the normal time being 19.1 °. .09 ° (= X ₅ ) ≦ ε ₃ ≦ 79.1 ° (= X ₆ ) (see formulas (2-8) and (2-9)) (−ε ₃ ) When the phase of the short-circuit current I _Ry is delayed by (+ λ ₃ ) within a predetermined third short-circuit current angle range λ ₃ (40.9 ° ≦ λ ₃ ≦ 100.9 °), the phase between the T phase and the R phase Judged as a short circuit accident.
K ₃ = [(20.79) ² + (108.02 × 85/110) ² ] ^1/2
= 86.0 (V) (2-7)
^{_{X 5 = cos -1 (20.79 /}} 110) -cos -1 (20.79 / 86.02)
= 3.09 (°) (2-8)
X ₆ = 60 + 19.1
= 79.1 (°) (2-9)
(4) In case of short-circuit accident between R phase, S phase and T phase The voltage value of the composite voltage V _RS-2T is less than or equal to the predetermined fourth composite voltage value K ₄ = 85 V (75 to 80% of the rated voltage). The phase of the composite voltage V _RS-2T at the time of the short-circuit accident is a predetermined fourth composite voltage angle range ε ₄ (wherein the phase of the composite voltage V _RS-2T at the normal time is 19.1 °. −3.09 ° (= −X ₅ ) ≦ ε ₄ ≦ 7.10 ° (= X ₁ )) (that is, the same phase), and the phase of the short-circuit current I _Ry is predetermined. When the angle is within the fourth short-circuit current angle range λ ₄ (−30.0 ° ≦ λ ₄ ≦ 30.0 °), it is determined that the short-circuit accident occurs between the R phase, the S phase, and the T phase.

(Fifth accident mode determination method)
The accident appearance judging transformer 120 (accident appearance judging transformer according to the second embodiment of the present invention) shown in FIG. 15 is installed on the bus, and the composite voltage V _R− output from the accident appearance judging transformer 120 is provided. _{Based on} the voltage value and phase of _{S + 2T} and the phase of the short-circuit current I _Ry , the accident aspect is determined as follows.
Here, the secondary side of the accident phase determination transformer 120 has the R-phase voltage V _R in the polarity direction, the S-phase phase voltage V _S in the opposite polarity direction, and the T-phase phase voltage V _T in the polarity direction. They are wired so as to be doubled in the direction of synthesis. As a result, the composite voltage V _{R−S + 2T} output from the accident aspect determination transformer 120 is expressed by the following equation.
V _{R−S + 2T} = V _R −V _S + 2V _T
Further, although the impedance angle θ is usually 75 °, the phase angle of the short-circuit current I _Ry takes into consideration the arc resistance, from 30 ° (−45 °) to 90 ° (+ 15 °) which is the maximum angle at the time of a short-circuit accident. ).

(1) In the case of a short-circuit accident between the R phase and the S phase The voltage value of the composite voltage V _{R-S + 2T} is equal to or less than a predetermined fifth composite voltage value K ₅ = 100.1 V (see equation (3-1)) ), And the phase of the composite voltage V _{R-S + 2T} at the normal time is 280.9 °, and the phase of the composite voltage V _{R-S + 2T} at the time of the short-circuit accident is a predetermined fifth composite voltage The angle range ε ₅ (7.10 ° (= X ₇ ) ≦ ε ₅ ≦ 40.9 ° (= X ₈ ), see (3-2) and (3-3))) (− ε ₅ ) and the phase of the short-circuit current I _Ry is delayed (+ λ ₅ ) by a predetermined fifth short-circuit current angle range λ ₅ (79.1 ° ≦ λ ₅ ≦ 139.1 °) It is determined as a short-circuit accident between the R phase and the S phase.
K ₅ = [(83.15) ² + (72.01 × 85/110) ² ] ^1/2
= 100.1 (V) (3-1)
^{_{X 7 = cos -1 (83.15 /}} 110.0) -cos -1 (83.15 / 110.05)
= 7.10 (°) (3-2)
X ₈ = 280.9-240
= 40.9 (°) (3-3)
(2) In the case of a short circuit accident between the S phase and the T phase The voltage value of the composite voltage V _{R-S + 2T} is equal to or less than a predetermined sixth composite voltage value K ₆ = 86.0 V (see formula (3-4)) ), And the phase of the composite voltage V _{R-S + 2T} at the normal time is 280.9 ° as a reference, the phase of the composite voltage V _{R-S + 2T} at the time of the short-circuit accident is a predetermined sixth composite voltage Angular range ε ₆ (3.09 ° (= X ₉ ) ≦ ε ₆ ≦ 79.1 ° (= X ₁₀ ) (see equations (3-5) and (3-6))) (+ ε ₆ ) and the phase of the short-circuit current I _Ry is delayed by (+ λ ₆ ) within the predetermined sixth short-circuit current angle range λ ₆ (19.1 ° ≦ λ ₆ ≦ 79.1 °) It is determined as a short-circuit accident between phase T and phase T.
K ₆ = [(20.79) ² + (108.02 × 85/110) ² ] ^1/2
= 86.0 (V) (3-4)
X ₉ = cos ⁻¹ (20.79 / 110) −cos ⁻¹ (20.79 / 86.02)
= 3.09 (°) (3-5)
X ₁₀ = 360-280.9
= 79.1 (°) (3-6)
(3) In the case of a short-circuit accident between the T phase and the R phase The voltage value of the composite voltage V _{R-S + 2T} is a predetermined seventh composite voltage value K ₇ = 107.6 V or less (see equation (3-7)) ), And the phase of the composite voltage V _{R-S + 2T} at the normal time is 280.9 ° as a reference, the phase of the composite voltage V _{R-S + 2T} at the time of the short-circuit accident is a predetermined seventh composite voltage Angular range ε ₇ (4.12 ° (= X ₁₁ ) ≦ ε ₇ ≦ 19.1 ° (= X ₁₂ ) (see equations (3-8) and (3-9)) (+ ε ₇ ) and the phase of the short-circuit current I _Ry is delayed by (+ λ ₇ ) within a predetermined seventh short-circuit current angle range λ ₇ (139.1 ° ≦ λ ₇ ≦ 199.1 °) Judged as a short-circuit accident between phase-R.
K ₇ = [103.94 ² + (36.01 × 85/110) ² ] ^1/2
= 107.6 (V) (3-7)
^{_{X 11 = cos -1 (103.94 /}} 110) -cos -1 (103.94 / 107.60)
= 4.12 (°) (3-8)
X ₁₂ = 300-280.9
= 19.1 (°) (3-9)
(4) In the case of a short-circuit accident between the R phase, the S phase, and the T phase, the voltage value of the composite voltage V _{R-S + 2T} is equal to or less than a predetermined eighth composite voltage value K ₈ = 85 V (75 to 80% of the rated voltage) And the phase of the composite voltage V _{R-S + 2T} at the time of a short-circuit accident is a predetermined eighth composite on the basis that the phase of the composite voltage V _{R-S + 2T} at a normal time is 280.9 ° It is within the voltage angle range ε ₈ (−7.10 ° (= −X ₇ ) ≦ ε ₈ ≦ 3.09 ° (= X ₉ )) (that is, in phase), and the short circuit current I _When the phase of _Ry is delayed by (+ λ ₈ ) within a predetermined eighth short-circuit current angle range λ ₈ (68.2 ° ≦ λ ₈ ≦ 128.2 °) (between R phase, S phase, and T phase) Judged as a short circuit accident.

The arithmetic processing unit multiplies the short-circuit current when the accident mode determination result indicates a short-circuit accident between the T phase and the R-phase, and short-circuits when it indicates a short-circuit accident between the R phase and the S phase. When the current is 1/3 times and the accident mode determination result indicates a short circuit accident between the S phase and the T phase, the short circuit current is 1/2 times and the accident mode determination result is R phase-S phase-T. To indicate a short circuit accident between phases, the short circuit current is 1/7 ^1/2 times. Further, the arithmetic processing unit sets the load current I to 1/7 ^1/2 times.

As shown in FIG. 16, the arithmetic processing unit includes an accident aspect determination circuit 71 that determines an accident aspect using any of the first to fifth accident aspect determination methods described above, and a two-phase through current transformer. A first amplitude adjustment circuit 72 ₁ that doubles the short-circuit current, a second amplitude adjustment circuit 72 ₂ that doubles the short-circuit current, and a second amplitude adjustment circuit 72 ₃ that doubles the short-circuit current When, a fourth amplitude adjusting circuit 72 ₄ for multiplying the load current I and the short-circuit current 1/7 ^1/2, first, second, based in accordance with a switch control signal S _SW input from accidents aspect determination circuit 71 4 of any one of the output signal of the amplitude adjusting circuit 72 ₁ to 72 ₄ may be constituted by a selection switch 73 for selecting.

The selection switch 73 normally selects the output signal of the _fourth amplitude adjustment circuit 724. Thus, when the short circuit does not occur, the load current I from the two-phase through current transformer, the after being 1/7 ^1/2 In the fourth amplitude adjusting circuit 72 _4, the selection switch 73 To the short circuit protection relay.

If the accident aspect determination circuit 71 determines that “a short-circuit accident between the T phase and the R phase”, it outputs a switch control signal _SSW that causes the selection switch 73 to select the output signal of the _first amplitude adjustment circuit 72 ₁ . As a result, when a short circuit accident between the T phase and the R phase occurs, the short circuit current from the two-phase through current transformer is multiplied by ₁ in the first amplitude adjustment circuit 721, and then passed through the selection switch 73. Input to short-circuit protection relay.

In addition, when the accident aspect determination circuit 71 determines that “a short-circuit accident between the R phase and the S phase”, the switch control signal _SSW that causes the selection switch 73 to select the output signal of the _second amplitude adjustment circuit ₇₂₂ is output. To do. Thus, when the short circuit of the R-phase -S phase occurs, after the short-circuit current of two phases through current transformer, which is 1/3 in the second amplitude adjusting circuit 72 _2, the selection switch 73 To the short circuit protection relay.

Further, when the accident aspect determination circuit 71 determines that “a short-circuit accident between the S phase and the T phase”, it outputs a switch control signal _SSW that causes the selection switch 73 to select the output signal of the _third amplitude adjustment circuit ₇₂₃ . To do. Thus, when the short circuit of the S-phase -T phase occurs, the short-circuit current of two phases through the current transformer, the after being half the third amplitude adjustment circuit 72 _3, the selection switch 73 To the short circuit protection relay.

Furthermore, when the accident aspect determination circuit 71 determines that “a short circuit accident between the R phase, the S phase, and the T phase”, the switch control signal that causes the selection switch 73 to select the output signal of the _fourth width adjustment circuit 724. S _SW is output. As a result, when a short circuit accident between the R phase, the S phase, and the T phase occurs, the short circuit current from the two-phase through current transformer is multiplied by 1/7 ^{1/2 in the} _fourth width adjustment circuit 724. Thereafter, the signal is input to the short-circuit protection relay via the selection switch 73.

  As a result, the amplitude of the short-circuit current can be made the same regardless of the accident aspect, so that the detection sensitivity and the operation time of the short-circuit protection relay can be made the same.

Next, a fifth embodiment of the protective relay device of the present invention will be described with reference to FIG. 17 and FIG.
As shown in FIG. 17, the protective relay device according to the present embodiment includes a two-phase through current transformer 10 installed in a transmission and distribution line, a short-circuit current I _Ry input from the two-phase through current transformer 10, and a bus. When a short circuit accident is detected on the transmission / distribution line based on the voltage information (phase voltages V _R , V _S , V _T ) input from the instrument transformer 6 installed in the transmission line, the R phase and S phase of the transmission / distribution line And an overcurrent relay with voltage suppression 50 that collectively cuts off the _first to _third circuit breakers 2 ₁ to 2 ₃ installed in the T phase, respectively.

Here, the two-phase through current transformer 10 is a through-type current transformer in which an R-phase and an S-phase of a power transmission / reception line are crossed in an opposite direction at an arbitrary angle through an annular core around which a secondary coil is wound. It is a vessel. That is, the R phase of the transmission / distribution line is penetrated in the polarity direction of the two-phase through current transformer 10, while the S phase of the transmission / distribution line is penetrated in the opposite polarity direction of the two-phase penetration current transformer 10.
In addition, the R phase of the transmission / distribution line passes through the two-phase through current transformer 10 only once, but the S phase of the transmission / distribution line passes through the two-phase through current transformer 10 twice. Thereby, the two-phase through current transformer 10 outputs a difference current between a current flowing through the R phase of the transmission and distribution line and a current that is twice the current flowing through the S phase.

Therefore, the load current I input from the two-phase through current transformer 10 to the overcurrent relay 50 with voltage suppression when no short circuit has occurred is the same as that in the overcurrent relay 4 according to the first embodiment described above. Similarly, the vector difference between the R-phase load current I _R and the current obtained by doubling the S-phase load current I _S (= 2I _S ), and the amplitude of the load current I is the R-phase load current I _R (S 7 ^1/2 times the amplitude of the phase load current I _S ) (see FIG. 2A).
I = I _R -2I _S
| I | = | I _R −2I _S | = 7 ^1/2 × | I _R | (= 7 ^1/2 × | I _S |)
Thus, since the amplitude of the load current I is 7 ^1/2 times the amplitude of the R-phase load current I _R (S-phase short-circuit current I _FS ), the overcurrent relay 50 with voltage suppression is expressed by the following equation: As shown, the load current I is multiplied by 1/7 ^1/2 to calculate a corrected load current I ′.
I ′ = I × 1/7 ^1/2 = (I _R −2I _S ) × 1/7 ^1/2
| I ′ | = | I _R −2I _S | × 1/7 ^1/2 = | I _R | (= | I _S |)

Moreover, when the short-circuit currents flowing in the R-phase, S-phase, and T-phase of the transmission and distribution line when a short-circuit accident occurs are represented by I _FR , I _FS , and I _FT , the short-circuit current I _Ry is the first implementation described above. As in the case of the overcurrent relay 4 according to the example, it is expressed as follows according to the accident aspect.
(1) In case of short-circuit accident between R phase and S phase (see Fig. 3 (a))
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR −2I _FS | = 3 × | I _FR | (= 3 × | I _FS |)
(2) In the case of a short circuit accident between the S phase and the T phase (see FIG. 3B)
I _Ry = -2I _FS
| I _Ry | = 2 × | I _FS |
(3) In the case of a short circuit accident between T phase and R phase (see Fig. 4 (a))
I _Ry = I _{FR
| I Ry | = | I FR} |
(4) In the case of a short circuit accident between R phase, S phase, and T phase (see FIG. 4B)
I _Ry = I _FR -2I _FS
| I _Ry | = | I _FR −2I _FS | = 7 ^1/2 × | I _FR | (= 7 ^1/2 × | I _FS |)

The overcurrent relay with voltage suppression 50 calculates the corrected short-circuit current I _Ry ′ as follows in order to make the detection sensitivity and the operation time the same for all accident aspects.
(1) In the case of a short circuit accident between the R phase and the S phase The amplitude of the short circuit current I _Ry is three times the amplitude of the R phase short circuit current I _FR (the S phase short circuit current I _FS ). The corrected short circuit current I _Ry 'is calculated by multiplying the short circuit current I _Ry by 1/3.
I _Ry '= I _Ry × 1/3 = (I _FR −2I _FS ) × 1/3
| I _Ry '| = | I _FR -2I _FS | × 1/3 = | I _FR | (= | I _FS |)
(2) Since the amplitude when the short-circuit current I _Ry of short circuit of the S-phase -T phase is made twice the amplitude of the short-circuit current I _FS of S phase, the short-circuit current I _Ry as shown in the following equation 1/2 The corrected short-circuit current I _Ry ′ is calculated by multiplying.
I _Ry '= I _Ry × 1/2 = -2I _FS × 1/2 = −I _FS
| I _Ry '| = | I _FS |
(3) amplitude when the short-circuit current I _Ry of short circuit of the T-phase -R phase since the amplitude of the short-circuit current I _FR of R-phase, correction short to 1 times the short-circuit current I _Ry as shown in the following equation The current I _Ry 'is calculated.
I _Ry '= I _Ry × 1 = I _FR
| I _Ry '| = | I _FR |
(4) In case of short-circuit accident between R-phase, S-phase and T-phase The amplitude of short-circuit current I _Ry is 7 ^1/2 times the amplitude of R-phase short-circuit current I _FR (S-phase short-circuit current I _FS ). As shown in the following equation, the short-circuit current I _Ry is multiplied by 1/7 ^1/2 to calculate the corrected short-circuit current I _Ry '.
I _Ry '= I _Ry × 1/7 ^1/2 = (I _FR -2I _FS ) × 1/7 ^1/2
| I _Ry '| = | I _FR -2I _FS | × 1/7 ^1/2 = | I _FR | (= | I _FS |)

The overcurrent relay with voltage suppression 50 obtains the suppression voltage V _Ry as follows when determining the accident aspect using the first accident aspect determination method described above.
(1) Normal time The R-phase and S-phase line voltage V _RS obtained from the R-phase and S-phase voltages V _R and V _S inputted from the instrument transformer 6 is _defined as a suppression voltage V _Ry .
V _Ry = V _RS
(2) In case of short-circuit accident between R-phase and S-phase R-phase and S-phase line voltage V _RS obtained from R-phase and S-phase phase voltages V _R and V _S input from instrument transformer 6 The suppression voltage is V _Ry .
V _Ry = V _RS
(3) In the case of a short-circuit accident between the S phase and the T phase The S-phase and T-phase line voltage V _ST obtained from the S-phase and T-phase phase voltages V _S and V _T input from the instrument transformer 6 The suppression voltage is V _Ry .
V _Ry = V _ST
(4) In the case of a short-circuit accident between the T phase and the R phase The line voltage V _TR between the T phase and the R phase obtained from the phase voltages V _T and V _{R of the} T phase and the R phase input from the instrument transformer 6 The suppression voltage is V _Ry .
V _Ry = V _TR
(5) In case of short-circuit accident between R phase, S phase, and T phase R-phase and S-phase line voltage obtained from R-phase and S-phase phase voltages V _R and V _S input from instrument transformer 6 Let V _RS be the suppression voltage V _Ry .
V _Ry = V _RS

Further, the overcurrent relay 50 with voltage suppression, when determining the accident aspect using the second or third accident aspect determination method described above, the T-phase and R-phase input from the instrument transformer 6 Using the T-phase to R-phase line voltage V _TR (see FIG. 2B) obtained from the phase voltages V _T and V _R , the suppression voltage V _Ry is obtained as follows according to the accident aspect. Note that V = V _TR ∠ (210 ° + α).
(1) When normal V _Ry = V
(2) In case of short circuit accident between R phase and S phase V _Ry = 2 × V × cos (60 ° + α)
(3) In case of short circuit accident between S phase and T phase V _Ry = 2 × V × cos (60 ° + α)
(4) In case of short-circuit accident between T phase and R phase V _Ry = V
(5) In case of short circuit between R phase, S phase and T phase V _Ry = V

Further, the overcurrent relay 50 with voltage suppression uses the composite voltage V _RS-2T input from the accident aspect determination transformer 110 when determining the accident aspect using the fourth accident aspect determination method described above. The suppression voltage V _Ry is obtained as follows according to the accident aspect.
(1) When normal V _Ry = V _RS-2T
(2) In the case of a short-circuit accident between the R phase and the S phase V _Ry = 110 × (V _RS-2T −83.15) /26.85
(3) In the case of a short circuit accident between the S phase and the T phase V _Ry = 110 × (V _RS-2T −103.94) /6.06
(4) In the case of a short circuit accident between the T phase and the R phase V _Ry = 110 × (V _RS-2T -20.79) /89.21
(5) In case of short circuit between R phase, S phase and T phase V _Ry = V _RS-2T

The overcurrent relay with voltage suppression 50 determines the accident aspect using the fifth accident aspect determination method described above, and the combined voltage V _{R-S +} input from the accident aspect determination transformer 120. _{Using 2T} , the suppression voltage V _Ry is obtained as follows according to the accident aspect.
(1) When normal V _Ry = V _{R-S + 2T}
(2) In the case of a short circuit accident between the R phase and the S phase V _Ry = 110 × (V _{R−S + 2T} −83.15) /26.85
(3) In the case of a short circuit accident between S phase and T phase V _Ry = 110 × (V _{R−S + 2T} −20.79) /89.21
(4) In the case of a short-circuit accident between the T phase and the R phase V _Ry = 110 × (V _{R−S + 2T} −103.94) /6.06
(5) In case of short circuit between R phase, S phase and T phase V _Ry = V _{R-S + 2T}

The overcurrent relay with voltage suppression 50 corrects the current set value determined by the voltage suppression characteristic that defines the magnification of the current set value according to the suppression voltage V _Ry when the amplitude of the correction short-circuit current I _Ry ′ exceeds The first to third circuit breakers 2 ₁ to 2 ₃ are collectively cut off. FIG. 18 shows an example of voltage suppression characteristics.

  The two-phase through-current transformer 10 penetrates the R phase of the transmission / distribution line once and the S phase twice, but penetrates the S phase of the transmission / distribution line once and the T phase twice. It may be penetrated, or the T phase of the transmission / distribution line may be penetrated once and the R phase may be penetrated twice.

  In the above description, the two-phase through current transformer is made to penetrate the R phase once and the S phase twice, but the number of times the R phase and the S phase are made to penetrate the two-phase through current transformer is m. Times and n times (m ≠ n).

Further, in the fourth accident mode determination method described above, the R-phase phase voltage V _R is 2 in the polarity direction, the S-phase phase voltage V _S is in the opposite polarity direction, and the T-phase phase voltage V _T is 2 in the opposite polarity direction. The secondary side of the accident aspect determination transformer 110 is connected so as to be combined, and in the fifth accident aspect determination method described above, the phase voltage V _R of the R phase is in the polarity direction and the phase voltage V of the S phase. the _S in the opposite polarity direction, has been connected to the secondary side of the accident aspect determination transformer 120 to combine with double the polarity direction phase voltage V _T of the T-phase, the phase voltage V _R of the R-phase Multiply a in the polar or antipolar direction by a, multiply the S phase voltage V _S by b in the polar or antipolar direction, and multiply the _T phase voltage V _T by c in the polar or antipolar direction The secondary side of the accident mode determination transformer may be connected so as to be combined. The composite voltage V _{aR + bS + cT} output from this accident aspect determination transformer is expressed by the following equation.
V _{aR + bS + cT} = ± aV _R ± bV _S ± cV _T

  Although the two-phase through current transformer of the present invention has been described above in combination with the short-circuit protective relay used in the transmission and distribution line, the two-phase through current transformer of the present invention is for driving, for example, a limb of a robot. Even when combined with a short-circuit protection device used in a three-phase AC circuit that supplies power to the three-phase motor (three-phase load), the same effect can be obtained.

It is a figure for demonstrating the protection relay apparatus by 1st Example of this invention. It is a diagram for explaining the load current I and the T-phase -R phase phase voltage V _R of the line voltage V _TR and R-phase when a short circuit does not occur. It is a figure for demonstrating short circuit current _IRy input into the overcurrent relay 4 from the two-phase through current transformer 10 shown in FIG. 1 when a short circuit accident generate | occur | produces. It is a figure for demonstrating short circuit current _IRy input into the overcurrent relay 4 from the two-phase through current transformer 10 shown in FIG. 1 when a short circuit accident generate | occur | produces. It is a figure for demonstrating the short circuit current _IRy input into the overcurrent relay 4 when the short circuit accident generate | occur | produces between R phase-S phases of the power transmission and distribution line shown in FIG. It is a figure for demonstrating short circuit current _IRy input into the overcurrent relay 4 when a short circuit accident generate | occur | produces between the S phase-T phases of the power transmission and distribution line shown in FIG. It is a figure for demonstrating short circuit current _IRy input into the overcurrent relay 4 when a short circuit accident generate | occur | produces between the T phase-R phases of the power transmission and distribution line shown in FIG. It is a figure for demonstrating short circuit current _IRy input into the overcurrent relay 4 when a short circuit accident generate | occur | produces between R phase-S phase-T phases of the power transmission and distribution line shown in FIG. It is a figure for demonstrating the protective relay apparatus by the 2nd Example of this invention. It is a figure for demonstrating the protection relay apparatus by the 3rd Example of this invention. It is a figure for demonstrating the protective relay apparatus by the 4th Example of this invention. It is a figure for demonstrating the 2nd accident aspect determination method. It is a figure for demonstrating the 3rd accident aspect determination method. It is a figure which shows the structure of the transformer 110 for an accident aspect determination used in the 4th accident aspect determination method. It is a figure which shows the structure of the transformer 120 for accident aspect determination used in the 5th accident aspect determination method. It is a figure which shows the example of 1 structure of the arithmetic processing part for making detection sensitivity and operation time, such as the overcurrent relay 4 shown in FIG. 1, the same. It is a figure for demonstrating the protective relay apparatus by the 5th Example of this invention. It is a figure which shows an example of a voltage suppression characteristic. It is a figure for demonstrating the conventional method which protects from a short circuit accident by installing an overcurrent relay only in two phases by the transmission / distribution line etc. of a terminal circuit.

Explanation of symbols

1 power supply 2 _{1 to} 2 _{6 first} to _sixth circuit breakers 3 ₁ and 3 ₂ first and second current transformers 4 and 30 overcurrent relays 4 ₁ and 4 ₂ first and second overcurrent relays 5 Transformer 6 Instrument transformer 10 Two-phase through current transformer 10 ₁ , 10 ₂ First and second two-phase through current transformer 20 Current differential relay 50 Overcurrent relay with voltage suppression 60 ₁ , 60 ₂ First And second PCM current differential relay 71 Accident aspect determination circuit 72 _{1 to} 724 ₄ 1st to 4th amplitude adjustment circuit 73 Select switch 110, 120 Accident aspect determination transformer 1L, 2L The first and second transmissions Distribution line I, I _R , I _S , I _T Load current I ′ Corrected load current i ₁ , I _1R , I _1S , I _1T Primary load current i ₂ , I _2R , I _2S , I _2T Secondary load current I _a , I _aR , I _aS , I _aT transmitting end load current I _b , I _bR , I _bS , I _bT receiving end load current I _Ry , I _FR , I _FS , I _FT short Fault current I _Ry 'Corrected short-circuit current V _R , V _S , V _T phase voltage V _RS , V _ST , V _TR line voltage V _RS-2T , V _{R-S + 2T} composite voltage V _Ry suppression voltage S _SW switch control Signal θ Impedance angles k1, k2 First and second voltage values α, β Angle ranges γ, δ First and second angle ranges K _{1 to} K ₈ First to eighth combined voltage values ε _{1 to} ε ₈ First to eighth combined voltage angle ranges λ _{1 to} λ ₈ First to eighth short-circuit current angle ranges

Claims (17)

A two-phase through current transformer (10; 10 ₁ , 10 ₂ ) for detecting a short-circuit current flowing in each phase of a three-phase AC circuit, wherein the three-phase AC circuit is mounted on an annular core wound with a secondary coil A two-phase through current transformer, characterized in that any two phases of the above are passed through in opposite directions for different numbers of times.   One of the two arbitrary phases of the three-phase AC circuit is penetrated in the polarity direction of the two-phase through current transformer, and the other one of the arbitrary two phases of the three-phase AC circuit The two-phase through current transformer according to claim 1, wherein a phase is penetrated in a direction opposite to the polarity of the two-phase through current transformer.   Computation processing means is provided for determining an accident aspect of a short-circuit accident of the three-phase AC circuit and multiplying a short-circuit current detected by the two-phase through current transformer by a predetermined multiple according to the determination result of the accident aspect. The two-phase through current transformer according to claim 1 or 2, wherein A protective relay device for protecting a three-phase AC circuit from a short circuit accident,
A two-phase through current transformer according to any one of claims 1 to 3,
When a short-circuit fault is detected based on the short-circuit current input from the two-phase through current transformer, a short-circuit protective relay that collectively shuts off the circuit breakers installed in each phase of the three-phase AC circuit;
A protective relay device comprising:   The protective relay device according to claim 4, wherein the two-phase through current transformer and the short-circuit protective relay are installed only for the two arbitrary phases of the three-phase AC circuit. The protective relay device is
Accident aspect determining means for determining the accident aspect of the short circuit accident of the three-phase AC circuit;
Arithmetic processing means for multiplying the short-circuit current detected by the two-phase through current transformer by a predetermined multiple according to the determination result of the accident aspect in the accident aspect determination means,
The protective relay device according to claim 4, further comprising: The accident mode determination means determines whether the three-phase AC circuit has three line voltages (V _RS , V _ST , V _TR ), three phase voltages (V _R , V _S , V _T ), or a phase / line voltage. The protective relay device according to claim 6, wherein an accident aspect of a short circuit accident of the three-phase AC circuit is determined based on the basis. The accident mode determination means is based on the voltage value and phase of one line voltage (V _RS , V _ST , V _TR ) and one phase voltage (V _R , V _S , V _T ) of the three-phase AC circuit. The protective relay device according to claim 6, wherein an accident aspect of a short circuit accident of the three-phase AC circuit is determined. The accident mode judging means is configured to _detect a voltage value and phase of one line voltage (V _RS , V _ST , V _TR ) of the three-phase AC circuit and a short-circuit current (I _Ry) input from the two-phase through current transformer. The protective relay device according to claim 6, wherein an accident aspect of a short-circuit accident of the three-phase AC circuit is determined based on the phase of (). The first phase voltage (V _R ) of the three-phase AC circuit is in the polarity direction, and the second phase voltage (V _S ) of the three-phase AC circuit is in the opposite polarity direction. The first to second phases are used for determining the accident aspect of the short-circuit fault of the three-phase AC circuit, where the secondary side is connected so as to synthesize the phase voltage (V _T ) by doubling in the opposite polarity direction. An accident mode judging transformer (110) for obtaining a composite voltage (V _RS-2T ) of the phase voltages of the three phases;
The accident aspect determination means is based on the voltage value and phase of the combined voltage input from the accident aspect determination transformer and the phase of the short-circuit current (I _Ry ) input from the two-phase through current transformer. Determine the accident aspect of the short circuit accident of the three-phase AC circuit,
The protective relay device according to claim 6. The first phase voltage (V _R ) of the three-phase AC circuit is in the polarity direction, and the second phase voltage (V _S ) of the three-phase AC circuit is in the opposite polarity direction. The first to third are used for determining the accident aspect of the short-circuit accident of the three-phase AC circuit in which the secondary side is connected so that the phase voltage (V _T ) is doubled and synthesized in the polarity direction. A fault condition judging transformer (120) for obtaining a composite voltage (V _{R-S + 2T} ) of the phase voltages of the phases;
The accident aspect determination means is based on the voltage value and phase of the combined voltage input from the accident aspect determination transformer and the phase of the short-circuit current (I _Ry ) input from the two-phase through current transformer. Determine the accident aspect of the short circuit accident of the three-phase AC circuit,
The protective relay device according to claim 6. The first phase voltage (V _R ) of the three-phase AC circuit is multiplied by a in the polarity direction or the antipolar direction, and the second phase voltage (V _S ) of the three-phase AC circuit is changed in the polarity direction or antipolar direction. And the secondary side is connected so that the third phase voltage (V _T ) of the three-phase AC circuit is multiplied by c in the polarity direction or the opposite polarity direction to be combined, and the three-phase AC A _fault condition judging transformer for obtaining a composite voltage (V _{aR + bS + cT} ) of the phase voltages of the first to third phases used for judging the accident situation of the short circuit accident of the circuit;
The accident aspect determination means is based on the voltage value and phase of the combined voltage input from the accident aspect determination transformer and the phase of the short-circuit current (I _Ry ) input from the two-phase through current transformer. Determine the accident aspect of the short circuit accident of the three-phase AC circuit,
The protective relay device according to claim 6. The two-phase through current transformer (10) is installed in a transmission and distribution line;
Arbitrary two phases of the transmission / distribution line are passed through the annular iron core of the two-phase through current transformer in different directions in different directions,
When the short-circuit protective relay detects a short-circuit fault based on a short-circuit current (I _Ry ) input from the two-phase through current transformer, first to third breakers installed in each phase of the transmission and distribution line Is an overcurrent relay (4) that collectively shuts off the devices (2 _{1 to} 2 ₃ ),
The protective relay device according to claim 4, wherein The two-phase through current transformers are first and second two-phase through current transformers (10 ₁ , 10 ₂ ) respectively installed on the primary side and the secondary side of the transformer (5);
Arbitrary two phases on the primary side of the transformer are passed through the annular core of the first two-phase through current transformer in different directions in different directions,
The arbitrary two phases on the secondary side of the transformer are passed through the annular iron core of the second two-phase through current transformer in opposite directions by a different number of times,
The short-circuit protection relay detects a short-circuit accident based on a difference current between a short-circuit current input from the first two-phase through current transformer and a short-circuit current input from the second two-phase through current transformer Then, the _first to _third circuit breakers (2 ₁ to 2 ₃ ) installed in the respective phases on the primary side of the transformer and the fourth to fourth circuit breakers installed on the respective phases on the secondary side of the transformer. 6 is a current differential relay (20) that collectively cuts off ₆ circuit breakers (2 ₄ to 2 ₆ ).
The protective relay device according to claim 4, wherein The two-phase through current transformers are first and second two-phase through current transformers (10 ₁ , 10 ₂ ) installed in the first and second transmission and distribution lines (1L, 2L), respectively.
Arbitrary two phases of the first power transmission and distribution line are passed through the annular iron core of the first two-phase through current transformer in different directions in opposite directions,
The arbitrary two phases of the second power transmission and distribution line are passed through the annular iron core of the second two-phase through current transformer in different directions in opposite directions,
When the short-circuit protection relay detects a short-circuit accident based on a sum current of a short-circuit current input from the first two-phase through current transformer and a short-circuit current input from the second two-phase through current transformer The _first to _third circuit breakers (2 ₁ to 2 ₃ ) installed in each phase of the first transmission / distribution line and the fourth to sixth circuits installed in each phase of the second transmission / distribution line An overcurrent relay (30) that collectively shuts off the circuit breakers (2 _{4 to} 2 ₆ ).
The protective relay device according to claim 4, wherein The two-phase through current transformers are first and second two-phase through current transformers (10 ₁ , 10 ₂ ) respectively installed on the power supply terminal bus side and the power receiving terminal bus side of the transmission and distribution lines;
Any two phases of the transmission and distribution lines are penetrated through the annular iron core of the first two-phase through current transformer in different directions in opposite directions,
The arbitrary two phases of the power transmission and distribution line are penetrated through the annular iron core of the second two-phase through current transformer in opposite directions by a different number of times,
The short-circuit protection relay detects a short-circuit accident based on a difference current between a short-circuit current detected by the first two-phase through current transformer and a short-circuit current detected by a second two-phase through current transformer; The _first to _third circuit breakers (2 ₁ to 2 ₃ ) installed in each phase of the transmission / distribution line on the power supply end bus side and installed in each phase of the transmission / distribution line on the power receiving end bus side And first and second pulse code modulation current differential relays (60 ₁ , 60 ₂ ) that collectively cut off the _fourth to _sixth circuit breakers (2 ₄ to 2 ₆ ), respectively.
The protective relay device according to claim 4, wherein The two-phase through current transformer (10) is installed in a transmission and distribution line;
Arbitrary two phases of the transmission / distribution line are passed through the annular iron core of the two-phase through current transformer in different directions in different directions,
The short-circuit protection relay uses a short-circuit current (I _Ry ) input from the two-phase through current transformer and a suppression voltage (V _RS , V _ST , V _TR ) calculated using the line voltages (V _RS , V _ST , V _TR ). (V _Ry ) and an overcurrent relay with voltage suppression that collectively shuts off the _first to _third circuit breakers (2 ₁ to 2 ₃ ) installed in each phase of the transmission and distribution line. 50),
The protective relay device according to claim 4, wherein