JP2009295839A - Cross through current transformer, terminal block, and protective relay device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cross through current transformer, a terminal block, and a protective relay device which are capable of furthermore reducing the number of installed current transformers and short-circuit protection relays for protecting a three-phase alternating circuit from short-circuit faults. <P>SOLUTION: A cross through current transformer 10 includes first and second primary conductors 12<SB>1</SB>and 12<SB>2</SB>and a toroidal core 16 having a secondary coil 14 wound therearound, wherein the first primary conductor 12<SB>1</SB>pierces the toroidal core 16 in a direction from a first aperture surface of the toroidal core 16 to a second aperture surface of the toroidal core 16, and the second primary conductor 12<SB>2</SB>pierces the toroidal core 16 in a direction from the second aperture surface of the toroidal core 16 to the first aperture surface of the toroidal core 16. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cross-through current transformer, a terminal block, and a protective relay device, and is particularly 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 cross-through current transformer, a terminal block, and a protective relay device.

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

FIG. 15 shows an example of a through current transformer 510 used as such a current transformer.
The through current transformer 510 is attached to the casing 511, the primary conductor 512 having both ends attached to the input-side primary terminal 513 _I and the output-side primary terminal 513 _O , the secondary coil 514, and the upper surface of the casing 511. Two secondary terminals 515 to which both ends of the secondary coil 514 are respectively connected, an annular core 516 around which the secondary coil 514 is wound, and an outer peripheral surface and both side surfaces of the annular core 516 are surrounded. A shield 517 attached to the inside of the housing 511 and an attachment 518 attached to the bottom surface of the housing 511 are provided.
Here, in order to connect one phase of the power transmission / distribution line to the input-side primary terminal 513 _I and the output-side primary terminal 513 _O and pass through the primary conductor 512 in the polarity direction of the through current transformer 510, Is formed with a through hole for allowing the primary conductor 512 to pass through from one side surface (the left side surface in FIG. 15) to the other side surface (the right side surface in the same figure) of the housing 511. Reference numeral 516 is attached to the inside of the housing 511 so that the first and second opening surfaces respectively face both side surfaces of the housing 511.
Further, the secondary coil 514, the annular iron core 516, and the shield 517 are molded with resin and housed in the housing 511.

In addition, in the case of terminal circuit transmission and distribution lines, instead of installing an overcurrent relay for each phase, by installing the overcurrent relay only in two phases using the short circuit current flowing in two phases, the equipment cost We are trying to suppress this.
For example, as shown in FIG. 16, first and second through current transformers 510 ₁ and 510 ₂ respectively installed in the R phase and the T phase of the R phase, S phase, and T phase of the transmission and distribution lines When the first and second overcurrent relays 4 ₁ and 4 ₂ are connected to each other and a short-circuit accident occurs in the transmission / distribution line, the R-phase, S The _first to _third circuit breakers 2 ₁ to 2 ₃ installed in the phase and the T phase are collectively disconnected by the first and second overcurrent relays 4 ₁ and 4 ₂ , respectively.
(1) Since the R-phase and short-circuit current in the S phase when transmission and distribution lines of a short circuit of the R-phase -S phase flows, the short-circuit current which is input through the first through current transformer 510 ₁ installed in the R phase first overcurrent relay 4 ₁ collectively cut off the first to third circuit breaker 2 ₁ to 2 ₃ operates based on.
(2) In the case of a short circuit accident between the S phase and the T phase Since a short circuit current flows in the S phase and the T phase of the transmission and distribution line, the short circuit current input from the _second current transformer 5102 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 T-phase of the transmission and distribution line, the first and second current transformers 510 ₁ installed in the R-phase and T-phase, respectively. , first and second overcurrent relay 4 _1, 4 ₂ are collectively cut off the first to third circuit breaker 2 ₁ to 2 ₃ operates in response to the short-circuit current which is inputted from the 510 _2.
(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 based on the short-circuit currents input from 510 ₁ and 510 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 through current transformers and two overcurrent relays are installed for each transmission / distribution line, there are the following problems.
(1) There is a demand to reduce the installation cost by further reducing the number of through current transformers and overcurrent relays installed.
(2) If the number of overcurrent relays is two, the three-phase AC circuit can be protected from a short circuit accident in its own circuit, but the phase where no overcurrent relay is installed and other circuits Moreover, since the short circuit accident which straddles cannot be detected, the short circuit protection relay on the power source side protects the three-phase AC circuit, thereby expanding the range of the power failure.
(3) When there are two overcurrent relays installed, if one overcurrent relay becomes unavailable due to failure or inspection, the three-phase AC circuit cannot be protected from a short circuit accident.

  Such a problem is a current differential relay for protecting the three-phase AC circuit from a short circuit accident inside the transformer, a power receiving protection relay or a split power receiving protective relay for protecting the three phase AC circuit from a short circuit accident in the premises. There are also overcurrent relays used, and pulse code modulation current differential relays (PCM current differential relays) installed and used on the power supply terminal bus side and the power reception terminal bus side of the transmission and distribution lines.

  An object of the present invention is to provide a cross-through current transformer, a terminal block, 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. There is to do.

The cross-through current transformer of the present invention has a first and second primary conductors (12 ₁ , 12 ₂ ; 22 ₁ , 22 ₂ ) and an iron core (16; wound around) a secondary coil (14; 24). 26), wherein the first primary conductor is penetrated in a direction from the first opening surface of the iron core to the second opening surface of the iron core, and the second primary conductor is The iron core is penetrated in a direction from the second opening surface of the iron core to the first opening surface of the iron core.
The terminal block of the present invention is a terminal block (30) incorporating the function of the cross-through current transformer of the present invention, and both end portions of the first primary conductor (32 ₁ ) are arranged inside the terminal block. 1 is connected to an outer terminal (41 _O1 ) and a second inner terminal (41 _I2 ), respectively, and both ends of the _second primary conductor (32 ₂ ) are connected to the second outer terminal inside the terminal block. (41 _O2 ) and the first inner terminal (41 _I1 ), respectively, and the iron core (36) around which the secondary coil (34) is wound is connected to the first and second primary conductors. It is provided inside the terminal block between the first outer and inner terminals and the second outer and inner terminals so as to cross and penetrate the iron core, and both ends of the secondary coil are connected to each other. Two secondary terminals (35) formed between the first and second inner terminals It is provided in.
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 built in the cross-through current transformer (10; 20) of the present invention or the terminal block of the present invention. and cross through current transformer is, short-circuit current which is input from the cross through current transformer; upon detecting a short circuit based on _{(I Ry I Ry1, I Ry2} ), installed to each phase of the three-phase AC circuit And a short-circuit protective relay (4; 4 ₁ , 4 ₂ ) for collectively breaking the circuit breakers (2 ₁ to 2 ₃ ).
Here, based on the three line voltages (V _RS , V _ST , V _TR ), the three phase voltages (V _R , V _S , V _T ) or the phase / line voltage of the three-phase AC circuit, You may further comprise the accident aspect determination means which determines the accident aspect of the short circuit accident of a phase alternating circuit.
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, You may further provide the accident aspect determination means which determines the accident aspect of a short circuit accident.
Based on the voltage value and phase of one line voltage (V _RS , V _ST , V _TR ) of the three-phase AC circuit and the phase of the short-circuit current (I _Ry ) input from the cross-through current transformer, You may further comprise the accident aspect determination means which determines the accident aspect of the short circuit accident of a three-phase alternating current circuit.
The secondary side supplies the first phase voltage (V _R ) of the three-phase AC circuit in the polarity direction and the second phase phase voltage (V _S ) of the three-phase AC circuit in the opposite polarity direction. A fault phase determination transformer (110) wired to synthesize the third phase voltage (V _T ) by doubling in the opposite polarity direction, and a composite voltage input from the fault mode determination transformer Accident aspect determining means for determining the accident aspect of the short-circuit accident of the three-phase AC circuit based on the voltage value and phase of (V _RS-2T ) and the phase of the short-circuit current input from the cross-through current transformer. Furthermore, you may comprise.
The secondary side supplies the first phase voltage (V _R ) of the three-phase AC circuit in the polarity direction and the second phase phase voltage (V _S ) of the three-phase AC circuit in the opposite polarity direction. A fault phase determination transformer (120) wired to synthesize the third phase voltage (V _T ) by doubling in the polarity direction, and a composite voltage ( An accident mode determination means for determining an accident mode of a short circuit accident of the three-phase AC circuit based on a voltage value and a phase of V _{R-S + 2T} ) and a phase of a short circuit current input from the cross-through current transformer; May further be provided.

The cross through current transformer, the terminal block, and the protective relay device of the present invention have the following effects.
(1) By using the cross-through current transformer of the present invention or the terminal block of the present invention, the number of installed current transformers and short-circuit protection relays for protecting the three-phase AC circuit from a short-circuit accident can be further reduced. The equipment cost can be reduced.
(2) By using two cross-through current transformers and two short-circuit protection relays, it is possible to reliably detect a short-circuit accident that spans the local circuit and other circuits, thus preventing the expansion of the power failure range. can do.
(3) By using two cross-through current transformers and two short-circuit protective relays, even if one short-circuit protective relay cannot be used due to a failure or inspection, the short circuit accident of its own circuit will cause a short circuit of the other one. Since it can be backed up by a protective relay, the three-phase AC circuit can be protected from a short circuit accident.

  For the above purpose, the first primary conductor is penetrated in the direction from the first opening surface of the iron core around which the secondary coil is wound to the second opening surface of the iron core, and the second primary conductor is passed through the first core conductor of the iron core. This was realized by constructing a cross-through current transformer by penetrating in the direction from the two opening surfaces to the first opening surface of the iron core.

Embodiments of the cross through current transformer, the terminal block, and the protective relay device of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1A and 1B, the cross through current transformer 10 according to the first embodiment of the present invention includes a housing 11 and first input side primary terminals 13 _I1 and first ends at both ends. the first primary conductor 12 _1, the second primary conductor at both ends is attached to the second input-side primary terminals 13 _I2 and the second output-side primary terminals 13 _O2 attached to the output side primary terminals 13 _O1 of 12 ₂ , the secondary coil 14, two secondary terminals 15 attached to the bottom of the housing 11 and connected to both ends of the secondary coil 14, and a ring around which the secondary coil 14 is wound An iron core 16, a shield (not shown) attached to the inside of the housing 11 so as to surround the outer peripheral surface and both side surfaces of the annular iron core 16, and a fixture 18 attached to the bottom surface of the housing 11 are provided.

  Here, the housing 11 includes a cylindrical portion for housing the annular iron core 16 and first and second side portions provided integrally on both side surfaces of the cylindrical portion.

  The annular core 16 has first and second opening surfaces that face each other on both side surfaces of the cylindrical portion of the casing 11 (that is, the annular core 16 has a first opening surface that is the first opening of the casing 11. And the second opening surface is parallel to the second side surface of the casing 11) and is attached to the cylindrical portion of the casing 11.

The first input-side primary terminal 13 _I1 is attached to one end face (the end face on the left side in FIG. 1A) of the first side surface portion of the housing 11, and the second input-side primary terminal 13 _I2 is The housing 11 is attached to one end surface (the end surface on the left side of the figure) of the second side surface portion. The first output-side primary terminal 13 _O2 is attached to the other end surface (the end surface on the right side in the figure) of the second side surface portion of the housing 11, and the second output-side primary terminal 13 _O2 is the housing. It is attached to the other end surface (the end surface on the right side of the figure) of the first side surface portion of the body 11.

The first primary conductor 12 ₁ is through the polarity direction of the cross through current transformer 10 (first direction from the opening face to a second opening surface of the annular core 16 of the toroid 16), but the second primary conductor 12 _{and second} is through the opposite polarity direction of the cross through current transformer 10 (the first direction to the opening surface of the annular core 16 from the second opening surface of the annular core 16).
In other words, so as to penetrate to cross the annular core 16 without first primary conductor 12 ₁ and the second primary conductor 12 ₂ are in contact with each other, the first primary conductor 12 _1, and FIG. 1 (b) As shown in FIG. 2, the first input side primary terminal 13 _I1 is bent upward and then bent so as to be horizontal, and penetrates from the first opening surface of the annular core 16 toward the second opening surface. After that, the first output side primary terminal 13 _O1 side is bent downward and then bent horizontally. On the other hand, the second primary conductor 12 ₂ is bent so as to horizontally after bent downward in the second input-side primary terminals 13 _I2 side, a first opening from the second opening surface of the annular core 16 After penetrating toward the surface, the second output side primary terminal 13 _O2 is bent upward so as to be horizontal.

As a result, in the cross through current transformer 10, the first primary conductor 12 ₁ and the second primary conductor 12 ₂ cross through the annular core 16 and pass through the first primary conductor 12 ₁ . The polarity of the current induced in the secondary coil 14 by the first current i ₁ is opposite to the polarity of the current induced in the secondary coil 14 by the second current i ₂ flowing through the second primary conductor 12 _2. Therefore, a current corresponding to the vector difference (= i ₁ −i ₂ ) between the first current i ₁ and the second current i ₂ is output from the secondary terminal 15.

  The secondary coil 14, the annular core 16 and the shield are molded with resin and housed in the housing 11.

Next, a cross through current transformer 20 according to a second embodiment of the present invention will be described with reference to FIG.
The cross through current transformer 20 according to the present embodiment is used as a low voltage current transformer, and includes a rectangular housing 20 as shown in FIGS. It differs from the cross through current transformer 10 according to the first embodiment described above in that a rectangular fixture 28 is provided on the bottom surface of the housing 20.

Also in the cross through current transformer 20, the first primary conductor 22 ₁ and the second primary conductor 22 ₂ cross the annular core 26 and pass through the first primary conductor 22 ₁ . The polarity of the current induced in the secondary coil 24 by the current i ₁ is opposite to the polarity of the current induced in the secondary coil 24 by the second current i ₂ flowing through the second primary conductor 22 ₂ . A current corresponding to the vector difference (= i ₁ −i ₂ ) between the first current i ₁ and the second current i ₂ is output from the secondary terminal 25.

  The form of the casing is not limited to the form having the cylindrical part and the first and second side parts as shown in FIG. 1 and the rectangular form as shown in FIG. It may be in the form of a bushing current transformer that is generally used as a current transformer.

  Next, a terminal block 30 according to an embodiment of the present invention having the function of the cross through current transformer of the present invention will be described with reference to FIG.

In the terminal block 30, as shown in FIG. 3, both ends of the first primary conductor 32 ₁ are respectively connected to the first outer terminal 41 _O1 and the second inner terminal 41 _I2 inside the terminal block 30. Both ends of the _second primary conductor 32 ₂ are respectively connected to the second outer terminal 41 _O2 and the first inner terminal 41 _I1 inside the terminal block 30, and the annular core 36 around which the secondary coil 34 is wound. However, the first outer and inner terminals 41 _O1 and 41 _I1 and the second outer and inner terminals 41 _O2 are arranged so that the first and second primary conductors 32 ₁ and 32 ₂ pass through the annular core 36. , 41 _I2 are provided in the terminal block 30, and the two secondary terminals 35 to which both ends of the secondary coil 34 are respectively connected are the first and second inner terminals 41 _I1 , 41 _I2 . It is provided in between.
Further, the annular iron core 42 on which the secondary coil is wound is connected to the third iron terminal 42 so that the conductive plate 44 connecting the third outer terminal 41 _O3 and the third inner terminal 41 _I3 passes through the annular iron core 42. It is provided in the terminal block 30 between the outer terminal 41 _O3 and the third inner terminal 41 _I3 .
Furthermore, two secondary terminals 43 to which both ends of the secondary coil wound around the annular core 42 are connected are provided in the vicinity of the third inner terminal 41 _I3 .

Accordingly, the first to third inner terminals 41 _{I1 to} 41 _I3 are connected to the first to third outer terminals 41 _{O1 to} 41 _O3 to connect the R phase, the S phase, and the T phase of the first transmission and distribution line, respectively. If the S phase, R phase, and T phase of the first transmission / distribution line are connected to the secondary terminal 35, the current flowing through the R phase of the first transmission / distribution line and the S phase of the first transmission / distribution line are connected to the secondary terminal 35, respectively. A secondary current corresponding to the vector difference from the flowing current can be obtained, and a secondary current corresponding to the current flowing through the T phase of the first transmission / distribution line can be obtained at the secondary terminal 43.
Therefore, if the secondary current obtained at the secondary terminal 35 and the secondary current obtained at the secondary terminal 43 are input to the short-circuit protection relay, the protective relay that protects the three-phase AC circuit from a short-circuit accident as described later. A device can be configured.

For the R-phase, S-phase, and T-phase of the second power transmission and distribution line, the fourth to sixth outer terminals 41 _{O4 to} 41 _O6 and the fourth to sixth inner terminals 41 _{I4 to} 41 _I6 of the terminal block 30 Are configured in the same manner, the second terminal 35 provided between the fourth and fifth inner terminals 41 _I4 and 41 _I5 and the current flowing through the R-phase of the second transmission and distribution line and the second transmission and distribution A secondary current corresponding to the vector difference from the current flowing through the S phase of the electric wire can be obtained, and the T phase of the second transmission / distribution electric wire is connected to the secondary terminal 43 provided in the vicinity of the sixth inner terminal 41 _I6. A secondary current corresponding to the current flowing through can be obtained.
Therefore, if the secondary current obtained at the secondary terminal 35 and the secondary current obtained at the secondary terminal 43 are input to another short-circuit protection relay, the three-phase AC circuit is protected from a short-circuit accident as described later. The protective relay device can be configured.

Next, a protective relay device according to a first embodiment of the present invention will be described with reference to FIGS.
The protective relay device according to the present embodiment is for protecting a three-phase power transmission / distribution line (three-phase AC circuit) from a short circuit accident by using one cross through current transformer 10 shown in FIG. As shown in FIG. 4, a cross-through current transformer 10 that is penetrated so that the R-phase and S-phase of the power transmission / distribution line cross each other and a short-circuit current I _Ry that is input from the cross-through current transformer 10 are used. And an overcurrent relay 4 that collectively shuts off 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 when a short circuit accident of the distribution line is detected. To do.

Here, since the R-phase and S-phase of the transmission / distribution line are passed through the cross-through current transformer 10, it flows in the R-phase, S-phase, and T-phase of the transmission / distribution line when no short circuit accident has occurred. When the load currents are represented by I _R , I _S , and I _T , the R-phase load current I _R and the S-phase load current I _S are cross-through changed with a phase difference of 120 ° as shown in FIG. Flow through the annular iron core 16 (see FIG. 1) of the flow device 10 in the opposite direction (that is, the R-phase load current I _R flows through the cross-through current transformer 10 in the polar direction, and the S-phase load). current I _S flows through the cross through current transformer 10 in the opposite polarity direction). Therefore, the amplitude of the load current I (the vector difference between the R-phase load current I _R and the S-phase load current I _S ) input from the cross-through current transformer 10 to the overcurrent relay 4 is the R-phase load current I. It becomes 3 ^1/2 times the amplitude of _R (S-phase load current I _S ).
I = I _R −I _S
| I | = | I _R −I _S | = 3 ^1/2 × | I _R | = 3 ^1/2 × | I _S |

In addition, R-phase of the transmission and distribution lines when the short circuit in the electric transmission has occurred, the short-circuit current flowing in the S-phase and T-phase I _FR, I _FS, expressed in I _FT, from the cross through the current transformer 10 over The short-circuit current I _Ry input to the current 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 occurs between the R phase and the S phase, the short circuit current I _FR of the R phase is generated in the R phase of the power transmission and distribution line as shown by the dashed arrows 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 input from the cross-through current transformer 10 to the overcurrent relay 4 is represented by the R-phase short-circuit current I _FR and the S-phase short-circuit current I _FS as indicated by the solid line thick arrows in FIG. The amplitude of the short-circuit current I _Ry is twice the amplitude of the R-phase short-circuit current I _FR (S-phase short-circuit current I _FS ) (see FIG. 6A). Short-circuit currents I _FR , I _FS , and I _FT flowing in the inner direction of the transmission / distribution line are indicated by solid arrows, and short-circuit currents I _FR , I _FS , and I _FT flowing in the outer direction of the transmission / distribution line are indicated by dashed-dotted arrows Yes.)
I _Ry = I _FR −I _FS
| I _Ry | = | I _FR −I _FS | = 2 × | I _FR | = 2 × | I _FS |
(2) In the case of a short-circuit accident between the S phase and the T phase When a short circuit accident between the S phase and the T phase occurs, the S phase short circuit current I _FS flows in the S phase of the transmission and distribution line in the internal direction, and the T of the transmission and distribution line Although the T-phase short-circuit current I _FT flows outward in the phase, the R-phase short-circuit current I _FR does not flow in the R-phase of the transmission and distribution line.
Therefore, the short-circuit current I _Ry input from the cross-through current transformer 10 to the overcurrent relay 4 becomes the S-phase short-circuit current −I _FS with a negative polarity, and the amplitude of the short-circuit current I _Ry is the S-phase short-circuit current I. The amplitude is _FS (see FIG. 6B).
I _Ry = −I _FS
| I _Ry | = | 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, a T phase short circuit current I _FT flows in the T phase of the transmission and distribution line, and the R of the transmission and distribution line. While the short-circuit current I _FR of R-phase to phase flows 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.
Accordingly, the short-circuit current I _Ry input from the cross-through current transformer 10 to the overcurrent relay 4 becomes the R-phase short-circuit current I _FR , and the amplitude of the short-circuit current I _Ry becomes the amplitude of the R-phase short-circuit current I _FR ( (Refer FIG.6 (c)).
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, short circuit current I of R phase to R phase, S phase, and T phase of the transmission and distribution line _FR and S-phase short-circuit current I _FS and T-phase short-circuit current I _FT flow in the internal direction with a phase difference of 120 °.
Therefore, the short-circuit current I _Ry input from the cross-through current transformer 10 to the overcurrent relay 4 is a vector difference between the R-phase short-circuit current I _FR and the S-phase short-circuit current I _FS, and the amplitude of the short-circuit current I _Ry is This is 3 ^1/2 times the amplitude of the R-phase short-circuit current I _FR (S-phase short-circuit current I _FS ) (see FIG. 6D).
I _Ry = I _FR −I _FS
| I _Ry | = | I _FR −I _FS | = 3 ^1/2 × | I _FR | = 3 ^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.

  Thus, by using the cross-through current transformer of the present invention, it is possible to prevent one short-circuit accident with one current transformer (cross-through current transformer 10) and one overcurrent relay (overcurrent relay 4). Three-phase transmission and distribution lines can be protected.

  In addition, although the cross-phase current transformer 10 penetrated the R phase and S phase of the transmission / distribution line, the S phase and T phase of the transmission / distribution line may be penetrated, or the R phase and T of the transmission / distribution line The phase may be penetrated.

As described above, by using the cross-through current transformer of the present invention, the number of installed current transformers and short-circuit protection relays can be further reduced. However, as described above, the amplitude of the short-circuit current I _Ry is an accident aspect. It depends on.
That is, the amplitude of the short-circuit current _IRy in the short-circuit accident between the R phase and the S-phase is twice the amplitude of the short-circuit current _IRy in the short-circuit accident between the S-phase and the T-phase and the short-circuit accident between the T-phase and the R-phase. The amplitude of the short-circuit current I _Ry in the short-circuit accident between the load current and the R phase-S phase-T phase is 3 ¹ of the amplitude of the short-circuit current I _Ry in the short-circuit accident between the S phase and the T phase and the short circuit accident between the T phase and the R phase ^{/ 2} times.
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 one of the following first to fifth accident aspect determination methods, and the short-circuit current _IRY output from the cross-through current transformer 10 is set to 1 according to the accident aspect determination result. You may provide the arithmetic processing part made to double, ^1/2 times, or 1/3 ^1/2 times between the cross penetration current transformer 10 and the short circuit protection relay, or in the 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, on the basis of the phase of the T-phase to R-phase line voltage V _TR being 210 ° and the phase of the R-phase voltage V _R being 0 ° (see FIG. 5B), 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 the angle range α (+ α) with reference to the phase = 210 °, it is determined that the short-circuit accident occurs between the R phase and the S phase (FIG. 7 ( 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 reference to the phase = 210 °, it is determined that there is a short circuit accident between the S phase and the T phase (FIG. 7). (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. 7C).
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 it is not (ie, larger than −6.76 ° and smaller than 6.76 °) (FIG. 7D). 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 I _Ry input from the cross-through current transformer 10.

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 the angle range α (+ α) with reference to the phase = 210 °, it is determined that the short-circuit accident occurs between the R phase and the S phase (FIG. 8 ( 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 there is a short circuit accident between the S phase and the T phase (FIG. 8). (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. 8C).
(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. 8D).

(Fourth accident mode determination method)
An accident aspect determination transformer 110 shown in FIG. 9 is installed in the bus, and based on the voltage value and phase of the composite voltage V _RS-2T output from the accident aspect determination transformer 110 and the phase of the short-circuit current _IRy. The accident aspect is judged 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 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 _RS-2T is equal to or less than a 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 (−19.1 ° ≦ λ ₄ ≦ 40.9 °), it is determined as a short-circuit accident between the R phase, the S phase, and the T phase.

(Fifth accident mode determination method)
10 is installed in the bus, and the voltage value and phase of the composite voltage V _{R-S + 2T} output from the accident mode determination transformer 120 and the phase of the short-circuit current I _Ry are set. Based on this, 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 (79.1 ° ≦ λ ₈ ≦ 139.1 °) (between R phase, S phase, and T phase) Judged as a short circuit accident.

The arithmetic processing unit multiplies the short-circuit current I _RY when the accident mode determination result indicates a short circuit accident between the S phase and the T phase or a short circuit accident between the T phase and the R phase, and the accident mode determination result is R To indicate a short-circuit accident between phase S and S-phase, halve the short-circuit current I _RY and when the accident mode judgment result indicates a short-circuit accident between R phase, S phase and T phase Short circuit current I _{RY is set} to 1/3 ^1/2 times. Further, the arithmetic processing unit sets the load current I to 1/3 ^1/2 times.

As shown in FIG. 11, the arithmetic processing unit includes an accident aspect determination circuit 71 that determines an accident aspect based on a line voltage, a phase voltage, or a phase / line voltage (combination of a phase voltage and a line voltage); A first amplitude adjustment circuit 72 ₁ that multiplies the short-circuit current I _Ry output from the cross-through current transformer 10, a second amplitude adjustment circuit 72 ₂ that doubles the short-circuit current I _Ry , and a load current I and short-circuit current I _Ry 1/3 ^1/2 multiplying third amplitude adjustment circuit 72 _3, first to third, based in accordance with a switch control signal S _SW input from accidents aspect determination circuit 71 of it may be constituted by a selection switch 73 for selecting one of the output signals of the amplitude adjusting circuit 72 ₁ to 72 _3.

The selection switch 73 normally selects the output signal of the _third amplitude adjustment circuit 723. Thus, when the short circuit does not occur, the load current I output from the cross through the current transformer 10, after which is 1/3 ^1/2 In the third amplitude adjusting circuit 72 _3, 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 R phase and the S phase”, it outputs a switch control signal _SSW that causes the selection switch 73 to select the output signal of the _second amplitude adjustment circuit 722. Thus, when the short circuit of the R-phase -S phase occurs, the short-circuit current I _Ry outputted from the cross through the current transformer 10, after which is half in the second amplitude adjusting circuit 72 _2, The signal is input to the short-circuit protection relay through the selection switch 73.

Further, when the accident aspect determination circuit 71 determines that “a short circuit accident between the S phase and the T phase” or “a short circuit accident between the T phase and the R phase”, the output signal of the _first amplitude adjustment circuit 72 ₁ is determined. A switch control signal _SSW to be selected by the selection switch 73 is output. Thereby, when a short circuit accident between the S phase and the T phase or a short circuit accident between the T phase and the R phase occurs, the short circuit current I _Ry output from the cross-through current transformer 10 is changed in the first amplitude adjustment circuit 72 ₁ . After being multiplied by 1, it is input to the short-circuit protection relay via the selection switch 73.

Further, 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 S that causes the selection switch 73 to select the output signal of the _third width adjustment circuit 723. Outputs _SW . As a result, when a short circuit accident between the R phase, the S phase, and the T phase occurs, the short circuit current I _Ry output from the cross-through current transformer 10 is reduced to 1/3 ¹ in the third amplitude adjustment circuit 72 ₃ . ^{/ twice} been then, is input to the short-circuit protection relay via the selection switch 73.

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

Next, a protective relay device according to a second embodiment of the present invention will be described with reference to FIGS.
The protective relay device according to this embodiment uses two cross-through current transformers 10 shown in FIG. 1 (first and second cross-through current transformers 10 ₁ , 10 ₂ ) to prevent a three-phase AC from a short-circuit accident. It is intended to protect the circuit, as shown in FIG. 12, R-phase and S-phase of the transmission and distribution lines are the first cross through current transformer 10 ₁ is penetrated to cross, the transmission and distribution lines The second cross-through current transformer 10 ₂ penetrated so that the R phase and the T phase cross each other, and the first short-circuit current I _Ry1 input from the first cross-through current transformer 10 _1. The first overcurrent relay 4 that collectively shuts off 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 when a short circuit accident of the distribution line is detected. ₁ and, second second short-circuit current I _Ry2 short of transmission and distribution lines on the basis of the input from the cross-through current transformer 10 ₂ Upon detection of a fault comprises a second overcurrent relay 4 ₂ for collectively blocking the first to third circuit breaker 2 ₁ to 2 _3.

Here, since the first cross through the current transformer 10 ₁ extends through the R-phase and S-phase of the transmission and distribution lines, R-phase of the transmission and distribution lines when the short circuit does not occur, S-phase and When the load currents flowing in the T phase are represented by I _R , I _S , and I _T , as shown in FIG. 13, the R phase load current I _R and the S phase load current I _S have a first phase difference of 120 °. flowing cross through current transformer 10 ₁ toroid (see toroids 16 shown in FIG. 1) through the opposite direction (i.e., the R-phase load current I _R is the first cross through current transformer 10 flow through ₁ to polarity direction, the load current I _S of the S-phase flow through the first cross through current transformer 10 ₁ in the opposite polarity direction). Therefore, the first load current I ₁ which is input from the first cross through current transformer 10 ₁ in the first overcurrent relay 4 ₁ of the load current I _S of the load R-phase current I _R and S-phase The first load current I _{1 has} an amplitude that is 3 ^1/2 times the amplitude of the R-phase load current I _R (S-phase load current I _S ). I ₁ = I _R −I _S
| I ₁ | = | I _R −I _S | = 3 ^1/2 × | I _R | = 3 ^1/2 × | I _S |
Similarly, since the second cross through current transformer 10 ₂ R-phase and T-phase of the transmission and distribution lines are through, the load current of the R-phase as shown in FIG. 13 I _R and T phases of the load current and I _T flows through the second cross through current transformer 10 ₂ toroid (see toroid 16 shown in FIG. 1) in the opposite direction with a phase difference of 120 ° (i.e., the R-phase load current I _R is the load current I _T of the second cross through current transformer 10 ₂ flows through the polarity direction, T phase flows through the second cross through current transformer 10 ₂ in the opposite polarity direction) . Therefore, the second load current I ₂ from the second cross through current transformer 10 ₂ is inputted second overcurrent relay 4 ₂ of the load current I _T of the load R-phase current I _R and T phases As a result of the vector difference, the amplitude of the second load current I ₂ is 3 ^1/2 times the amplitude of the R-phase load current I _R (T-phase load current I _T ).
I ₂ = I _R −I _T
| I ₂ | = | I _R −I _T | = 3 ^1/2 × | I _R | = 3 ^1/2 × | I _T |

Also, R-phase of the transmission and distribution lines when the short circuit occurs in the transmission and distribution lines, the transmission and distribution lines flowing through the S-phase and T-phase R phase, S phase and the short-circuit current flowing through the T-phase I _FR, I _FS, expressed in I _FT, first and second short-circuit current I _Ry1, I _Ry2 is short-circuit current I _FR, I _FS, when the impedance angle I _FT theta, expressed as follows depending on the accident appearance The
(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.
Accordingly, the first short-circuit current I _Ry1 inputted from the first cross through current transformer 10 ₁ in the first overcurrent relay 4 _1, short-circuit current of the R-phase as shown by the solid line of thick arrows in FIG. 12 The vector difference between I _FR and the S-phase short-circuit current I _FS, and the amplitude of the first short-circuit current I _Ry1 is twice the amplitude of the R-phase short-circuit current I _FR (S-phase short-circuit current I _FS ) ( 14A, the short-circuit currents I _FR , I _FS , and I _FT flowing in the inner direction of the transmission / distribution line are solid arrows and the short-circuit current I _FR flowing in the outer direction of the transmission / distribution line in FIG. , I _FS , and I _FT are indicated by alternate long and short dashed arrows.)
I _Ry1 = I _FR -I _FS
| I _Ry1 | = | I _FR −I _FS | = 2 × | I _FR | = 2 × | I _FS |
Further, the second short-circuit current I _Ry2 input from the second cross-through current transformer 10 ₂ to the second overcurrent relay 4 ₂ is an R-phase short-circuit current as shown by a broken line in FIG. I _FR and the amplitude of the second short-circuit current I _{Ry2 is} the amplitude of the R-phase short-circuit current I _FR (see FIG. 14A).
I _Ry2 = I _FR
｜ I _Ry2 ｜ ＝ ｜ I _FR ｜
(2) In the case of a short-circuit accident between the S phase and the T phase When a short circuit accident between the S phase and the T phase occurs, the S phase short circuit current I _FS flows in the S phase of the transmission and distribution line in the internal direction, and the T of the transmission and distribution line Although the T-phase short-circuit current I _FT flows outward in the phase, the R-phase short-circuit current I _FR does not flow in the R-phase of the transmission and distribution line.
Accordingly, the first short-circuit current I _Ry1 inputted from the first cross through current transformer 10 ₁ in the first overcurrent relay 4 _1, short-circuit current -I _FS next polarity negative S phase, first The amplitude of the short-circuit current I _{Ry1 is} the amplitude of the S-phase short-circuit current I _FS (see FIG. 14B).
I _Ry1 = −I _FS
I _Ry1 = I _FS
| I _Ry1 | = | I _FS |
The second short-circuit current I _Ry2 input from the second cross-through current transformer 10 ₂ to the second overcurrent relay 4 ₂ is a T-phase short-circuit current −I _FT having a negative polarity, The amplitude of the short-circuit current I _{Ry2 is} the amplitude of the T-phase short-circuit current I _FT (see FIG. 14B).
I _Ry2 = −I _FT
| I _Ry2 | = | I _FT |
(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, a T phase short circuit current I _FT flows in the T phase of the transmission and distribution line, and the R of the transmission and distribution line. While the short-circuit current I _FR of R-phase to phase flows 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.
Accordingly, the first short-circuit current I _Ry1 inputted from the first cross through current transformer 10 ₁ in the first overcurrent relay 4 ₁ short-circuit current I _FR next to R-phase, the first short-circuit current I _Ry1 The amplitude is the amplitude of the R-phase short-circuit current I _FR (see FIG. 14C).
I _Ry1 = I _FR
｜ I _Ry1 ｜ ＝ ｜ I _FR ｜
The second short-circuit current I _Ry2 input from the second cross-through current transformer 10 ₂ to the second overcurrent relay 4 ₂ is the difference between the R-phase short-circuit current I _FR and the T-phase short-circuit current I _FT . The vector difference _{results in} the amplitude of the second short-circuit current I _{Ry2 being} twice the amplitude of the R-phase short-circuit current I _FR (T-phase short-circuit current I _FT ) (see FIG. 14C).
I _Ry2 = I _FR −I _FT
| I _Ry2 | = | I _FR −I _FT | = 2 × | I _FR | = 2 × | I _FT |
(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, short circuit current I of R phase to R phase, S phase, and T phase of the transmission and distribution line _FR and S-phase short-circuit current I _FS and T-phase short-circuit current I _FT flow in the internal direction with a phase difference of 120 °.
Accordingly, the first short-circuit current I _Ry1 inputted from the first cross through current transformer 10 ₁ in the first overcurrent relay 4 ₁ of the short-circuit current I _FS of the short circuit current I _FR and S phases of the R phase The amplitude of the first short circuit current I _Ry1 is 3 ^1/2 times the amplitude of the R phase short circuit current I _FR (S phase short circuit current I _FS ) (see FIG. 14D).
I _Ry1 = I _FR -I _FS
| I _Ry1 | = | I _FR −I _FS | = 3 ^1/2 × | I _FR | = 3 ^1/2 × | I _FS |
The second short-circuit current I _Ry2 input from the second cross-through current transformer 10 ₂ to the second overcurrent relay 4 ₂ is the difference between the R-phase short-circuit current I _FR and the T-phase short-circuit current I _FT . The vector difference _{results in} the amplitude of the second short-circuit current I _{Ry2 being} 3 ^1/2 times the amplitude of the R-phase short-circuit current I _FR (T-phase short-circuit current I _FT ) (see FIG. 14D).
I _Ry2 = I _FR −I _FT
| I _Ry2 | = | I _FR −I _FT | = 3 ^1/2 × | I _FR | = 3 ^1/2 × | I _FT |

First overcurrent relay 4 _1, when the amplitude of the first short-circuit current I _Ry1 exceeds the current setting value, it is determined that the short-circuit failure occurs in the transmission and distribution lines, the first to third Break breakers 2 _{1 to} 2 ₃ at _once .
The second overcurrent relay 4 _2, when the amplitude of the second short-circuit current I _Ry2 exceeds the current setting value, it is determined that the short-circuit failure occurs in the transmission and distribution lines, first to The circuit breakers 2 ₁ to 2 ₃ of ₃ are collectively shut off.

In this way, by using the cross-through current transformer of the present invention, two current transformers (first and second cross-through current transformers 10 ₁ and 10 ₂ ) and two overcurrent relays ( The first and second overcurrent relays 4 ₁ and 4 ₂ ) can protect the three-phase transmission and distribution lines from a short circuit accident.

The through a first cross through the current transformer 10 ₁ with passing the R-phase and S-phase of the transmission and distribution lines second cross through current transformer 10 to the _second transmission and distribution lines R-phase and T-phase However, the two phases of the power transmission / distribution wires passing through the first and second cross through current transformers 10 ₁ , 10 ₂ may be other combinations.

As described above, in the protective relay device according to the present embodiment, by using two cross-through current transformers of the present invention (first and second cross-through current transformers 10 ₁ and 10 ₂ ), can further reduce the number of installed current transformer and short-circuit protection relay, but the amplitude of the first and second short-circuit current I _Ry1, I _Ry2 differs depending accident aspects.
That is, the amplitude of the first short-circuit current I _Ry1 in the short-circuit accident between the R phase and the S-phase is the amplitude of the first short-circuit current I _Ry1 in the short-circuit accident between the S phase and the T phase and the short circuit accident between the T phase and the R phase. The amplitude of the first short-circuit current I _Ry1 in the short-circuit accident between the R phase, the S-phase, and the T-phase is doubled, and the amplitude of the first short-circuit current in the short-circuit accident between the S-phase and the T-phase and the short-circuit accident between the T-phase and the R-phase It becomes 3 ^1/2 times the amplitude of I _Ry1 .
The amplitude of the second short circuit current I _Ry2 in the short-circuit accident between the T phase and the R phase is the amplitude of the second short circuit current I _Ry2 in the short circuit accident between the R phase and the S phase and the short circuit accident between the S phase and the T phase. The amplitude of the second short-circuit current I _Ry2 in the short-circuit accident between the R phase, the S-phase, and the T-phase is doubled, and the amplitude of the second short-circuit current in the short-circuit accident between the R-phase and the S-phase It becomes 3 ^1/2 times the amplitude of I _Ry2 .
Therefore, the detection sensitivity and operating time of the short circuit protection relay cannot be made the same for all accident aspects.

Therefore, to determine the accident appearance using any one of the first to fifth accident aspect determination method described above, the accident aspects the first short-circuit current I _Ry1 output from the first cross through current transformer 10 ₁ 1x according to the determination result, 1/2-fold or 1/3 ^1/2 the first first arithmetic processing unit of the cross through current transformer 10 ₁ and short-circuit protection relay for (first overcurrent relay 4 ₁ ) or a short-circuit protection relay, and the second short-circuit current I _Ry2 output from the second cross-through current transformer 10 ₂ is 1 or 1/2 times depending on the accident mode judgment result Alternatively, a second arithmetic processing unit that is 1/3 ^1/2 times is provided between the second cross-through current transformer 10 ₂ and the short-circuit protection relay (second overcurrent relay 4 ₂ ) or in the short-circuit protection relay. May be.

  For example, when the first accident aspect determination method described above is used, the first and second arithmetic processing units are shown in Table 2 as the accident aspect determination method based on the three line voltages shown in Table 1. The accident aspect of the short-circuit accident is determined using the accident aspect determination method based on the three phase voltages or the accident aspect determination method based on the phase / line voltage shown in Table 3.

First arithmetic processing unit, accident aspects determination result output from the first cross through the current transformer 10 ₁ to indicate that a short-circuit accident or T phase -R phase short fault of the S-phase -T phase The first short-circuit current I _Ry1 to be multiplied by 1 and when the accident mode judgment result indicates a short-circuit accident between the R phase and the S phase, the first short-circuit current I _Ry1 is halved and the accident When the result of the mode determination indicates that a short circuit accident between the R phase, the S phase, and the T phase, the first short circuit current I _{Ry1 is set} to 1/3 ^1/2 times. Further, the first arithmetic processing unit sets the first load current I ₁ to 1/3 ^1/2 times.
Second arithmetic processing unit, accident aspects determination result is output from the cross-through current transformer 10 of the _second is to indicate that a short-circuit accident or S phase -T phase short fault of R-phase -S phase If the second short-circuit current I _Ry2 is multiplied by 1 and the accident mode judgment result indicates a short-circuit accident between the T-phase and the R-phase, the second short-circuit current I _Ry2 is halved and the accident In the case where the appearance determination result indicates a short circuit accident between the R phase, the S phase, and the T phase, the second short circuit current I _{Ry2 is set} to 1/3 ^1/2 times. Further, the second arithmetic processing unit sets the second load current I ₂ to 1/3 ^1/2 times.

As in the case of the arithmetic processing unit shown in FIG. 11, the first arithmetic processing unit determines the accident aspect based on the line voltage, phase voltage, or phase / line voltage (combination of phase voltage and line voltage). and accidents aspects judging circuit, first amplitude adjustment circuit for multiplying the first short-circuit current I _Ry1 1, and a second amplitude adjustment circuit for multiplying the first short-circuit current I _Ry1 1/2, first A third amplitude adjusting circuit that multiplies the load current I ₁ and the first short-circuit current I _Ry1 by 1/3 ^{1/2, and} first to third amplitudes according to the switch control signal input from the accident mode determination circuit. You may comprise with the selection switch which selects any one of the output signals of an adjustment circuit.

The selection switch normally selects the output signal of the third amplitude adjustment circuit. Thus, when no short-circuit accident has occurred, the first load current I ₁ is multiplied by 1/3 ^1/2 in the third amplitude adjustment circuit, and then the short-circuit protection relay (first 1 overcurrent relay 4 ₁ ).

When the accident aspect determination circuit determines that “a short-circuit accident between the R phase and the S phase”, it outputs a switch control signal that causes the selection switch to select the output signal of the second amplitude adjustment circuit. Thereby, when a short circuit accident between the R phase and the S phase occurs, the first short circuit current I _Ry1 is halved in the second amplitude adjustment circuit, and then the short circuit protection relay via the selection switch. Entered.

Further, when the accident aspect determination circuit determines that “a short circuit accident between the S phase and the T phase” or “a short circuit accident between the T phase and the R phase” occurs, the output signal of the first amplitude adjustment circuit is used as a selection switch. A switch control signal to be selected is output. Thereby, when a short circuit accident between the S phase and the T phase or a short circuit accident between the T phase and the R phase occurs, the first short circuit current I _Ry1 is multiplied by 1 in the first amplitude adjustment circuit, and then the selection switch Is input to the short-circuit protection relay.

Further, when the accident aspect determination circuit determines that “a short-circuit accident between the R phase, the S phase, and the T phase”, the switch outputs a switch control signal that causes the selection switch to select the output signal of the third width adjustment circuit. As a result, when a short circuit accident between the R phase, the S phase, and the T phase occurs, the first short circuit current I _Ry1 is multiplied by 1/3 ^1/2 in the third width adjustment circuit, and then the selection switch is turned on. To the short circuit protection relay.

As a result, since the amplitude of the first short-circuit current I _Ry1 can be made the same regardless of the accident aspect, the detection sensitivity and the operation time of the short-circuit protection relay can be made the same.

Similarly, the second arithmetic processing unit includes an accident aspect determination circuit that determines an accident aspect based on a line voltage, a phase voltage, or a phase / line voltage (a combination of a phase voltage and a line voltage); A first amplitude adjusting circuit for multiplying the short-circuit current I _Ry2 by 1, a second amplitude adjusting circuit for multiplying the second short-circuit current I _Ry2 by 1/2, a second load current I ₂ and a second short-circuit _Any one of the third amplitude adjustment circuit for multiplying the current I _Ry2 by 1/3 ^1/2 and the output signals of the first to third amplitude adjustment circuits according to the switch control signal input from the accident mode determination circuit You may comprise with the selection switch which selects any one.

The selection switch normally selects the output signal of the third amplitude adjustment circuit. Thus, when the short circuit does not occur, the second load current I ₂ that is output from the second cross through current transformer 10 ₂ is 1/3 ^1/2 In the third amplitude adjusting circuit Thereafter, the signal is input to the short-circuit protection relay (second overcurrent relay 4 ₂ ) via the selection switch.

When the accident aspect determination circuit determines that “a short circuit accident between the R phase and the S phase” or “a short circuit accident between the S phase and the T phase”, the selection switch selects the output signal of the first amplitude adjustment circuit. Outputs a switch control signal. Thus, when a short circuit accident between the R phase and the S phase or a short circuit accident between the S phase and the T phase occurs, the second short circuit current I _Ry2 is multiplied by 1 in the first amplitude adjustment circuit, and then the selection switch Is input to the short-circuit protection relay.

In addition, when the accident aspect determination circuit determines that “a short-circuit accident between the T phase and the R phase”, it outputs a switch control signal that causes the selection switch to select the output signal of the second amplitude adjustment circuit. As a result, when a short circuit accident occurs between the T phase and the R phase, the second short circuit current I _Ry2 is halved in the second amplitude adjustment circuit and then shorted via the selection switch. Input to protective relay.

Further, when the accident aspect determination circuit determines that “a short-circuit accident between the R phase, the S phase, and the T phase”, the switch outputs a switch control signal that causes the selection switch to select the output signal of the third width adjustment circuit. As a result, when a short circuit accident between the R phase, the S phase, and the T phase occurs, the second short circuit current I _Ry2 is multiplied by 1/3 ^1/2 in the third width adjustment circuit, and then the selection switch is turned on. To the short circuit protection relay.

As a result, since the amplitude of the second short-circuit current I _Ry2 can be made the same regardless of the accident aspect, the detection sensitivity and the operation time of the short-circuit protection relay can be made the same.

  In the protective relay according to the present embodiment, by using two cross-through current transformers and two short-circuit protective relays for each transmission / distribution line, it is possible to reliably detect even a short-circuit accident spanning the own circuit and other circuits. At the same time, even if one short circuit protection relay cannot be used due to failure or inspection, the short circuit accident of its own circuit can be backed up by another one short circuit protection relay.

  In the above, the cross-through current transformer of the present invention has been described in combination with the short-circuit protection relay used in the transmission / distribution line. The same effect can be obtained by combining with a short-circuit protection device used in a three-phase AC circuit that supplies power to a phase motor (three-phase load).

  In addition, as a protective relay device, what has been provided with an overcurrent relay to protect the three-phase AC circuit from a short-circuit accident, the current difference to protect the three-phase AC circuit from a short-circuit accident inside the transformer Active relays, overcurrent relays that are used as power protection protection relays or split power reception protection relays to protect three-phase AC circuits from short-circuit accidents on the premises, power supply bus side and power reception side bus side Even if it is equipped with a pulse code modulation current differential relay (PCM current differential relay) that is installed and used, the same effect can be obtained by combining with the cross-through current transformer of the present invention. it can.

  In addition, any two phases of the three-phase AC circuit were crossed once in the opposite direction through the annular core of the cross-through current transformer, but any two phases of the three-phase AC circuit crossed two or more times. Thus, any two phases of the three-phase AC circuit may be wound around the annular core of the cross-through current transformer the same number or different times so as to penetrate the cross-through current transformer. In this case, the primary conductor may be easily bent such as an insulated cable.

  Furthermore, although the cross penetration current transformer was comprised using the annular iron core, you may comprise a cross penetration current transformer using a cut core, a stacked iron core, etc. FIG.

It is a figure which shows the structure of the cross penetration current transformer 10 by 1st Example of this invention, (a) is a top view, (b) is a front view. It is a figure which shows the structure of the cross penetration current transformer 20 by the 2nd Example of this invention, (a) is a top view, (b) is a front view. It is a figure which shows the structure of the terminal block 30 by one Example of this invention provided with the function of the cross penetration current transformer of this invention. 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 inputted into overcurrent relay 4 from cross penetration current transformer 10 shown in Drawing 4 when a short circuit accident occurs. 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 of the overcurrent relay 4 etc. shown in FIG. 4 the same. It is a figure for demonstrating the protective relay apparatus by the 2nd Example of this invention. It is a figure for demonstrating the load current I when the short circuit accident has not occurred. The first and second cross-current transformers 10 ₁ and 10 ₂ shown in FIG. 12 and the first and second overcurrent relays 4 ₁ and 4 ₂ are respectively input to the first and second overcurrent relays 4 ₁ and 4 ₂ when a short circuit accident occurs. and second short-circuit current I _Ry1, is a diagram for explaining I _Ry2. It is a figure which shows the structure of an example of the through current transformer used as a current transformer for protecting a three-phase alternating current circuit from a short circuit accident. 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 2 ₁ to 2 ₃ of the first to the third circuit breakers 4,4 _1, 4 ₂ of the first and second overcurrent relay 10, 20 cross through the current transformer 10 _1, 10 ₂ first and second Cross-through current transformers 11, 21, 511 housings 12 ₁ , 12 ₂ , 22 ₁ , 22 ₂ , 32 ₁ , 32 ₂ first and second primary conductors 13 _I1 , 13 _I2 , 23 _I1 , 23 _I2 first And second input-side primary terminals 13 _O1 , 13 _O2 , 23 _O1 , 23 _O2 First and second output-side primary terminals 14, 24, 514 Secondary coils 15, 25, 35, 43, 515 Secondary terminal 16 , 26, 36, 42, 516 annular core 18, 28, 518 fixture 30 terminal block 41 _{O1 to} 41 _O6 first to sixth outer terminals 41 _{I1 to} 41 _I6 first to sixth inner terminals 44 conductive plate 71 accident aspects judging circuit 72 ₁ to 72 ₃ first to third amplitude adjusting circuit 73 selectively switches 110,120 accidents aspect determination transformer 510 through current transformer 510 _1, 510 ₂ first and second through current transformer 512 primary conductor 513 _I input side primary terminals 513 _O output side primary terminals 517 shields i _1, i ₂ the first and second current _{I Ry, I FR, I FS} , I FT short-circuit current I _Ry1, I _Ry2 first and second short-circuit current _{I, I R, I S,} I T load current I _1, I ₂ First and second load currents V _R , V _S , V _T phase voltages V _RS , V _ST , V _TR line voltage V _RS-2T , V _{R-S + 2T} composite voltage S _SW switch control signal θ impedance Angle α, β Angle range 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 1st to 8th short-circuit current angle range

Claims (8)

First and second primary conductors (12 ₁ , 12 ₂ ; 22 ₁ , 22 ₂ );
An iron core (16; 26) around which a secondary coil (14; 24) is wound;
The first primary conductor is penetrated in a direction from the first opening surface of the iron core to the second opening surface of the iron core;
The second primary conductor is penetrated in a direction from the second opening surface of the iron core to the first opening surface of the iron core;
A cross through current transformer characterized by that. A terminal block (30) incorporating the function of the cross-through current transformer according to claim 1,
Both ends of the first primary conductor (32 ₁ ) are respectively connected to the first outer terminal (41 _O1 ) and the second inner terminal (41 _I2 ) inside the terminal block,
Both ends of the _second primary conductor (32 ₂ ) are respectively connected to the second outer terminal (41 _O2 ) and the first inner terminal (41 _I1 ) inside the terminal block,
The iron core (36) around which the secondary coil (34) is wound has the first outer and inner terminals and the first terminal so that the first and second primary conductors pass through the iron core. Provided inside the terminal block between the outer and inner terminals of the two,
Two secondary terminals (35) to which both ends of the secondary coil are respectively connected are provided between the first and second inner terminals,
A terminal block characterized by that. A protective relay device for protecting a three-phase AC circuit from a short circuit accident,
Cross-through current transformer (10; 20) according to claim 1 or 2,
The cross through the short-circuit current which is input from the current transformer _{(I Ry; I Ry1, I} Ry2) detects a short circuit on the basis of the three-phase circuit breaker installed in each phase of the AC circuit (2 ₁ to 2 ₃ ) Short-circuit protective relay (4; 4 ₁ , 4 ₂ ) that shuts off all at _once ,
A protective relay device comprising: The three-phase AC circuit based on the three line voltages (V _RS , V _ST , V _TR ), the three phase voltages (V _R , V _S , V _T ) or the phase / line voltage of the three-phase AC circuit. 4. The protective relay device according to claim 3, further comprising an accident mode determination means for determining an accident mode of the short circuit accident. 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 3, further comprising an accident mode determination unit that determines an accident mode of a short circuit accident. Based on the voltage value and phase of one line voltage (V _RS , V _ST , V _TR ) of the three-phase AC circuit and the phase of the short-circuit current (I _Ry ) input from the cross-through current transformer, 4. The protective relay device according to claim 3, further comprising an accident mode determination means for determining an accident mode of a short circuit accident of a three-phase AC circuit. The secondary side supplies the first phase voltage (V _R ) of the three-phase AC circuit in the polarity direction and the second phase phase voltage (V _S ) of the three-phase AC circuit in the opposite polarity direction. A fault phase determination transformer (110) wired to synthesize the third phase voltage (V _T ) by doubling in the opposite polarity direction;
The three-phase AC circuit is short-circuited based on the voltage value and phase of the composite voltage (V _RS-2T ) input from the fault-mode determination transformer and the phase of the short-circuit current input from the cross-through current transformer. Accident aspect judging means for judging the accident aspect of the accident,
The protective relay device according to claim 3, further comprising: The secondary side supplies the first phase voltage (V _R ) of the three-phase AC circuit in the polarity direction and the second phase phase voltage (V _S ) of the three-phase AC circuit in the opposite polarity direction. An accident mode determination transformer (120) wired to synthesize the third phase voltage (V _T ) by doubling in the polarity direction;
The three-phase AC circuit is based on the voltage value and phase of the composite voltage (V _{R-S + 2T} ) input from the fault condition judging transformer and the phase of the short-circuit current input from the cross-through current transformer. Accident aspect judging means for judging the accident aspect of the short circuit accident,
The protective relay device according to claim 3, further comprising: