JP5830696B2 - Electric leakage detection device and method of forming core of electric leakage detection device - Google Patents

Description

  The present invention relates to a leakage detection device that detects leakage of power line wiring and the like.

  The leakage detecting device is a zero-phase current transformer (ZCT) comprising an annular core made of a soft magnetic material or the like having a plurality of primary conductors penetrated, and a toroidal coil wound around the core. It has. If a leakage occurs, a leakage current (zero-phase current) flows through one of the primary conductors, and the currents in the multiple primary conductors become unbalanced. Therefore, the core of the zero-phase current transformer is generated by the magnetic flux generated by the leakage current. The state of the magnetic flux at is changed. As a result, an induced voltage is generated in the coil of the zero-phase current transformer, and a voltage corresponding to the leakage current is generated at both ends of the coil. Further, when no leakage occurs, the currents flowing through the plurality of primary conductors are in an equilibrium state, the magnetic fluxes in the core of the zero-phase current transformer cancel each other, and no induced voltage is generated in the coil. Therefore, the leakage current can be detected by outputting the voltage across the coil of the zero-phase current transformer as the leakage detection output.

  However, in practice, the magnetic flux inside the core is non-uniform due to the influence of the position of the primary conductor, coil winding variation, and the like, and an induced voltage may be generated in the coil even in an equilibrium state. In addition, when a load device with a rush current such as a motor is connected to the load side of the primary conductor, the induced voltage generated in the coil becomes equal to or higher than the voltage for detecting the leakage current, causing false detection. Sometimes.

  In order to prevent such erroneous detection, the conventional leakage detection device uses an annular core, and the primary conductors to be penetrated are arranged densely in the center of the core, and the primary conductors are arranged symmetrically. In other words, the induced voltage of the coil in the equilibrium state is suppressed to suppress the output other than the zero-phase current.

  However, when the leakage detection device is incorporated into a device such as a leakage breaker, for example, in the configuration as described above, the shape of the primary conductor to be penetrated is different for each phase, the assemblability is deteriorated, and the conductor of each phase is It will be close. For this reason, there have been problems in terms of cost and performance, such as requiring an green product between the primary conductors, being susceptible to external magnetic influences, and increasing the temperature rise. On the other hand, it is possible to avoid the problem by separating the primary conductor by enlarging the annular core. However, there is a problem that structural restrictions increase in the incorporation into the device, and the device itself becomes large.

  On the other hand, in order to avoid an increase in the size of the annular core, there is also a configuration in which the primary conductors are separated from each other by using a substantially oval (track type) core (see, for example, Patent Document 1). However, in this configuration, although the problem related to the enlargement can be solved, the induced voltage of the coil in the equilibrium state becomes larger than that of the configuration in which the core is annular and the primary conductors are dense, and erroneous detection is likely to occur. There is a problem.

JP-A-7-083960

  As described above, in the conventional leakage detection device, in order to suppress the non-uniformity of the magnetic flux inside the core, the primary conductors are arranged close to the central portion of the core to easily cancel the magnetic fluxes generated by the primary conductors. However, when the core is circular, it is difficult to reduce the size. On the other hand, when considering the miniaturization and assemblability of the device, when the core is formed in an oval shape, there is a problem that magnetic flux in the core is likely to be non-uniform and erroneous detection is likely to occur.

  The present invention has been made in view of the above circumstances, and provides a leakage detecting device capable of suppressing erroneous detection and improving detection accuracy while having a configuration in which downsizing of an apparatus is easy and assembly is good. The purpose is to do.

The present invention is of an annular through which the primary conductor of the multiple inside, depends dimensions position in the radial direction, a core of magnetic material of substantially oblong shape with long sides and short sides, said a toroidal coil winding is wound along the circle of the core, and a detection unit for detecting an output voltage by the induced voltage generated in the coil, the core, the ring of the core circumferential direction of the The cross-sectional area is non-uniformly formed so that the cross-sectional area differs depending on the position, the cross-sectional area of the portion that intersects the short side is different from the cross-sectional area of the portion that intersects the long side, and the core is (1) a straight line extending in the longitudinal direction And a curved portion that connects both ends of the straight portion, and is formed substantially uniformly in the thickness direction. In the width direction, the connecting portion between the straight portion and the curved portion is larger than the width of the straight portion. Composed of clothoid curves with large width (2) formed substantially uniformly in the thickness direction, formed in the width direction with the same width over the entire circumference, and a notch or a slit is formed in a part of the circumferential direction of the ring of the core, 3) A leakage detecting device having any one of a width that is substantially uniform and a thickness that is unevenly formed so as to vary depending on a circumferential position of a ring of a core .
With the above configuration, even when the core has a substantially oval shape and the device is easy to downsize and has good assemblability, the position of the core when the primary conductor is spaced apart in the core. Can reduce the magnetic flux imbalance caused by the above. For this reason, it is possible to reduce the output when the current is in an equilibrium state, and it is possible to suppress erroneous detection and improve detection accuracy.

Further, the present invention is the above leakage detection device, wherein a plurality of primary conductors are penetrated inside the core, and three primary conductors are arranged in a line in the longitudinal direction of the substantially oval core. Among these primary conductors, one is positioned at the core center of the core, and the other two are disposed so as to be positioned symmetrically across the core center.
With the above configuration, since the primary conductor can be configured linearly with the same shape, it can be configured at low cost. Further, by providing symmetry in the arrangement of the primary conductors, it is possible to suppress erroneous detection of leakage in a balanced state.

In addition, with the straight portion in the core can be easily positioned. In addition, by smoothly changing the cross-sectional area using the clothoid curve, the corner of the connecting part that transitions from the straight part to the curved part is eliminated, so when winding the coil directly around the core of this part, Winding can be facilitated, and assemblability can be improved. Furthermore, magnetic flux unbalance caused by the position of the core can be reduced, and erroneous detection of leakage in the balanced state can be suppressed.

Further, while forming the width of the core in the same width, partially reduced the permeability by a circumferential part on the notch provided or slit ring of the core, can retain the magnetic flux passing through the core uniformly . In this case, the coil can be easily wound by configuring the core with the same width. Therefore, it is possible to suppress erroneous detection of leakage in an equilibrium state while improving assemblability.

Further, while forming the width of the core in the same width, by changing the thickness of the core can increase the cross-sectional area of the core portion where the magnetic flux is concentrated, it is possible to reduce the imbalance of magnetic flux generated by the position of the core . In this case, the coil can be easily wound by configuring the core with the same width. Therefore, it is possible to suppress erroneous detection of leakage in an equilibrium state while improving assemblability.

Further, the present invention is the above leakage detection device, wherein the core is formed to be substantially uniform in width and uneven in thickness so that it varies depending on a position in a circumferential direction of the ring of the core. In the above, the core includes a structure in which a plurality of soft magnetic materials are laminated, and a thick portion with an increased number of laminated layers is formed in a part of the circumference of the ring of the core.
With the above configuration, by increasing the number of laminated cores in a part of the laminated core, a thick portion can be formed to change the cross-sectional area of the core, and the magnetic flux imbalance caused by the position of the core can be reduced.
Also, the present invention is the above-described leakage detection device, wherein the core is built in a substrate, and the substrate is wound along a ring of the core on the outside of the core by a circuit pattern and a through hole. Including the one where the toroidal coil is formed.
With the above configuration, when the configuration has a substantially oval core, a toroidal coil in which the coil is wound over the entire circumference along the core ring can be easily formed. Further, by forming the core and the coil with the substrate, it is possible to eliminate the winding variation of the coil and to improve the detection accuracy and assembly accuracy of the zero-phase current transformer in the leakage detection device.

The present invention is a ring-shaped body that penetrates a plurality of primary conductors inward, the core is made of a substantially oval magnetic material having a long side and a short side, the dimension in the radial direction being different depending on the position, A method of forming a core of a leakage detection device comprising a toroidal coil in which a winding is wound along a ring and a detection unit that detects an output voltage due to an induced voltage generated in the coil, wherein the core is The cross-sectional area is different so that the cross-sectional area varies depending on the circumferential position of the ring of the core, the cross-sectional area of the portion that intersects the short side is different from the cross-sectional area of the portion that intersects the long side, In a state where a plurality of primary conductors are penetrated and arranged side by side in the longitudinal direction of the substantially oval core, the equilibrium position in a state where the plurality of primary conductors are closely arranged in the center of the core is used as a reference. Before equilibrium position The cross-sectional area of the portion corresponding to the displacement direction to the position of the primary conductor, greatly than the cross-sectional area of the portion in the displacement direction and symmetry, to provide a method of forming a core of the leakage detecting device.
With the above configuration, even when the core has a substantially oval shape and the device is easy to miniaturize and has good assembly properties, the cross-sectional area of the core can be changed according to the displacement of the primary conductor from the core center. The magnetic flux unbalance caused by the position of the core can be reduced by changing and increasing the cross-sectional area of the core where the magnetic flux is concentrated. For this reason, it is possible to reduce the output when the current is in an equilibrium state, and it is possible to suppress erroneous detection and improve detection accuracy.
Further, the present invention is a method of forming a core of the above leakage detection device, wherein the larger the amount of displacement of the core from the equilibrium position to the position where the primary conductor is disposed, the larger the cross-sectional area of the corresponding portion. Including those that form.
With the above configuration, the cross-sectional area of the core is changed according to the amount of displacement of the primary conductor from the center of the core, and the cross-sectional area of the core at the portion where the magnetic flux is concentrated is increased. Can be reduced, and erroneous detection can be suppressed.

  According to the present invention, it is possible to provide a leakage detecting device capable of suppressing erroneous detection and improving detection accuracy while easily reducing the size of the device and having good assembly.

The figure which shows the outline | summary of a structure of the leak detection apparatus which concerns on embodiment of this invention. The figure which shows the principal part structure of the leak detection apparatus which concerns on the 1st Embodiment of this invention. The figure which shows schematic structure of the whole of the leak detection apparatus which concerns on this embodiment The figure which shows the principal part structure of the leak detection apparatus which concerns on the 2nd Embodiment of this invention. The figure which shows the principal part structure of the leak detection apparatus which concerns on the 3rd Embodiment of this invention. The figure which shows the principal part structure of the leak detection apparatus which concerns on the 4th Embodiment of this invention. The figure which shows the principal part structure of the leak detection apparatus which concerns on the 5th Embodiment of this invention. The figure which shows the modification of 5th Embodiment The figure which shows the principal part structure of the leak detection apparatus which concerns on the 6th Embodiment of this invention. The figure which shows the principal part structure of the leak detection apparatus which concerns on the 7th Embodiment of this invention. The figure which shows the principal part structure of the leak detection apparatus which concerns on the 8th Embodiment of this invention. The block diagram which shows the structure of the leak detection apparatus which concerns on 8th Embodiment.

  In the present embodiment, as an example of a leakage detection device according to the present invention, a configuration of a leakage detection device including a zero-phase current transformer configured by winding a coil around an annular core is shown. This leakage detection device is used by being mounted on a switch such as an electronic breaker.

  FIG. 1 is a diagram showing an outline of the configuration of a leakage detection apparatus according to an embodiment of the present invention. Here, FIG. 1 (a) shows a configuration in the case where a two-phase primary conductor is disposed through the core and coil of the leakage detection device, and FIG. 1 (b) shows three layers of the core and coil of the leakage detection device. Configurations in the case where the primary conductor is disposed through are shown. In FIG. 1, the coil wound around the core is not shown.

  In the configuration shown in FIG. 1A, two primary conductors 11a and 11b are disposed so as to penetrate through a through hole of a core 10 made of a soft magnetic material such as permalloy. In the configuration shown in FIG. 1B, three primary conductors 21a, 21b, and 21c are disposed so as to penetrate through the through hole of the core 20 made of soft magnetic material. In the leakage detection device of the present embodiment, first, the cores 10 and 20 are formed in a substantially oval shape having a long side and a short side in order to achieve both reduction in size and improvement in assembly. Here, the substantially oval shape includes a ring shape having a long side and a short side, such as an oval shape (track type) and an oval shape, and includes shapes having different dimensions in two orthogonal directions. Shall be. The primary conductors 11a, 11b, 21a, 21b, and 21c are passed through the substantially elliptical through-holes of the non-circular cores 10 and 20, and a plurality of primary conductors are not close to each other but slightly apart from each other. Try to arrange.

  In the case of the above configuration, the magnetic characteristics of the coil and the core with respect to the primary conductor may differ depending on the position and may not be uniform as compared with the case where the primary conductor is closely arranged at the center of the perfect circle core. . Therefore, since the balance of magnetic characteristics may be lost depending on the arrangement position of the primary conductor, false detection is likely to occur. Therefore, in the present embodiment, the following configuration is adopted in order to reduce erroneous detection of leakage current.

  In the present embodiment, the cross-sectional area of the core is varied depending on the position, and the balance of the magnetic characteristics of the core and the coil is adjusted by setting the cross-sectional area of the core. Thereby, the imbalance of the magnetic flux produced by a position can be reduced. That is, based on the positional relationship between the core and the coil and the primary conductor, the cross-sectional area of the core is set so that the magnetic characteristics (magnetic resistance) of the coil and the core with respect to the primary conductor are equivalent at any position regardless of the position. . Thereby, an equivalent magnetic circuit is formed at all positions on the core.

  In the example of FIG. 1, the cross-sectional areas of the cores 10 and 20 are not uniform and differ according to the positional relationship between the substantially elliptical cores 10 and 20 and the primary conductors 11a, 11b, 21a, 21b, and 21c. . That is, different cross-sectional areas are set depending on the positions so that the cross-sectional areas of the cores 10 and 20 are correlated with the positions of the primary conductors 11a, 11b, 21a, 21b, and 21c.

  In the configuration of FIG. 1A, when a current flowing from the back to the front of the paper flows through the primary conductor 11a and a current flowing from the front to the back of the paper flows through the primary conductor 11b, the magnetic fluxes in the directions of arrows 15a and 15b respectively. Will occur. In the configuration of FIG. 1B, when a current flowing from the front to the back of the paper flows through the primary conductors 21a and 21c and a current from the back to the front of the paper flows through the primary conductor 21b, the arrows 25a, 25b, and 25c Magnetic flux is generated in each direction.

  In this state, in order to maintain the balance of magnetic characteristics, the distance between the primary conductor and the core is short, and the cross-sectional area of the core where the magnetic flux is concentrated is increased. Specifically, with respect to the arrangement positions of the primary conductors 11a, 11b, 21a, 21b, and 21c in the vicinity of the cores 10 and 20, the position when a plurality of primary conductors are closely arranged at the centers of the cores 10 and 20 is used as a reference. Thus, the cross-sectional areas of the cores 10 and 20 are made larger than the portions symmetrical to the direction in which the positions of the primary conductors 11a, 11b, 21a, 21b, and 21c are displaced. As a result, the primary conductors 11a, 11b, 21a, 21b, and 21c are formed so that the cross-sectional areas of the cores 10 and 20 at the portions become larger as they are closer.

  That is, in the case of FIG. 1A, since the primary conductors 11a and 11b are displaced in the longitudinal direction with respect to the center of the core 10, the cross-sectional areas S11 and S12 of the core 10 are made larger than the cross-sectional areas S13 and S14. Further, since the primary conductor 11b is displaced more in the longitudinal direction than the primary conductor 11a (displacement from the center: x2> x1), the cross-sectional area S12 of the core 10 is made larger than the cross-sectional area S11. Similarly, in the case of FIG. 1B, since the primary conductors 21a and 21c are displaced in the longitudinal direction with respect to the center of the core 20, the cross-sectional areas S21 and S22 of the core 20 are made larger than the cross-sectional areas S23 and S24. . Further, since the primary conductor 21b is displaced by y in the short direction with respect to the center of the core 20, the cross-sectional area S23 of the core 20 is made larger than the cross-sectional area S24.

  As shown in FIGS. 1 (a) and 1 (b), the leakage detection device according to the present embodiment has the same number of primary conductors that penetrate through the core as in the case of two primary conductors or three primary conductors. Regardless, it is applicable to both.

  As described above, by appropriately setting the cross-sectional area of the core so as to differ depending on the position, it is possible to reduce the unbalance of magnetic flux generated in the core, so that the equipment constituting the leakage detection device can be easily downsized and assembled easily. While having a simple configuration, it is possible to suppress erroneous detection and improve detection accuracy.

(First embodiment)
FIG. 2 is a diagram showing a main configuration of the leakage detection apparatus according to the first embodiment of the present invention. 2, (a) is a plan view of the core of the leakage detection device viewed from a direction perpendicular to the core ring, (b) is a side view of the core viewed from the side, and (c) is a plan view of the core and the coil. Respectively.

As shown in FIG. 2A, the core 30 is configured in a substantially oval shape such as an elliptical shape, and three primary conductors 31 </ b> R, 31 </ b> S, and 31 </ b> T through which a three-phase primary current flows through the through-hole of the core 30 penetrate. Are arranged. The primary conductors 31R, 31S, 31T are arranged side by side in the longitudinal direction of the through hole of the substantially elliptical core 30. Here, the primary conductor 31R is displaced by L ₁ from the center position of the core 30 to the core longitudinal, primary conductor 31S is displaced by H ₁ from the center position of the core 30 to the core lateral direction, the primary conductor 31T core 30 core longitudinally L ₂ from the center _of, and displaced by H ₂ in the core lateral direction.

As shown in FIG. 2 (b), the core 30 is a soft magnetic material are stacked, is formed in a substantially uniform thickness T _1. Further, as shown in FIG. 2C, a winding is wound around the core 30 along the ring of the core 30 to form a toroidal coil 32. The coil 32 is wound around the core 30 with a substantially uniform density, and the output of the coil 32 is taken out from the output portions 33 at both ends.

  In this configuration, it is assumed that a current flowing from the front to the back of the paper flows through the primary conductors 31R and 31T, and a current flowing from the back of the paper to the front flows through the primary conductor 31S. A magnetic flux is generated by the current flowing through each primary conductor and passes through the core 30. When there is no leakage and the currents flowing through the primary conductors 31R, 31S, and 31T are in an equilibrium state, the magnetic fluxes generated by the currents cancel each other, and no induced voltage is generated in the coil 32. However, when the cross-sectional area of the core 30 is uniform, even if the primary current is in an equilibrium state, an unbalance occurs in the magnetic flux of the entire core, an induced voltage is generated in the coil 32, and the output voltage is detected in the output unit 33. False detection may occur.

Therefore, in the present embodiment, the cross-sectional area of the core 30 is unevenly formed so as to vary depending on the position according to the positional relationship between the core 30 and the primary conductors 31R, 31S, and 31T. This makes the unbalanced magnetic flux uniform. Specifically, the core 30 has a large cross-sectional area where the magnetic flux concentrates, that is, a portion where the primary conductor is largely displaced from the core center and is close to the primary conductor. In the first embodiment, since the substantially uniform thickness of the core 30 at T _1, to change the cross-sectional area by changing the position of the width W of the core 30.

In FIG. 2A, the widths W ₂ and W ₄ at the positions of both end portions in the longitudinal direction of the core 30 according to the displacement in the longitudinal direction of the primary conductors 31R and 31T from the core center are set to the central portion close to the core center. It is made larger than the widths W ₁ and W _{3 at} the positions. Moreover, since the primary conductor 31S is displaced from the core center in the lateral direction, the width W ₁ of the position of the portion corresponding to the displacement direction, is larger than the width W ₃ of the position of the portion of the Symmetrically . Here, in each part of the core 30, the larger the displacement (L ₁ , L ₂ , H ₁ , H _{2 in} FIG. 2 (a)) of the adjacent primary conductor from the core center, the larger the core width of the corresponding part. Make it larger than the part of the symmetrical position. That is, the primary conductors 31R, 31S, and 31T are offset from the core center by (L ₁ , 0), (0, H ₁ ), and (L ₂ , H ₂ ), respectively. Set to change the width of. By configuring the core 30 in this manner, the magnetic characteristics of the coil and the core with respect to the primary conductor can be made equivalent at all positions, and the magnetic flux imbalance caused by the position on the core can be reduced. Detection can be suppressed.

FIG. 3 is a diagram showing an overall schematic configuration of the leakage detection apparatus according to the present embodiment. 3A is a schematic perspective view showing a zero-phase current transformer and a circuit board in which a plurality of primary conductors penetrate the coil and the core, and FIG. 3B is a circuit diagram showing components on the circuit board. . Primary conductors 31R, 31S, and 31T pass through the core 30, and output portions 33 at both ends of the coil 32 wound around the core 30 are connected to the circuit board 35 via connection conductors. The circuit board 35 constituting the leakage current detection unit includes a resistance R ₁ that matches the characteristic impedance Z ₁ of the coil 32, a detection circuit 36 that includes an IC or the like on which a circuit that detects the output voltage of the coil 32 is mounted, and a coil A reference resistor R ₂ for comparing the output voltages of 32 and a power supply 32 for supplying power to the detection circuit 36 are provided. A detection signal corresponding to the leakage detection voltage is output from the output section of the detection circuit 36.

(Second Embodiment)
FIG. 4 is a diagram showing a configuration of a main part of a leakage detecting apparatus according to the second embodiment of the present invention. 4, (a) is a plan view of the core of the leakage detection device as viewed from the direction perpendicular to the core ring, (b) is a side view of the core as viewed from the side, and (c) is a plan view of the core and coil. Respectively.

As shown in FIG. 4A, the core 40 is configured in an oval shape such as an ellipse, and three primary conductors 41R, 41S, and 41T through which a three-phase primary current flows through the through-hole of the core 40 penetrate. Are arranged. The primary conductors 41R, 41S, and 41T are arranged in a straight line in the longitudinal direction of the through hole of the substantially oval core 40. Here, the primary conductor 41R is displaced by L ₃ from the center position of the core 40 to the core longitudinal, primary conductor 41S is located in the center position of the core 40, a primary conductor 41T is L from the center of the core 40 to the core longitudinal It is displaced by ₄ .

As shown in FIG. 4 (b), the core 40 is a soft magnetic material are stacked, is formed in a substantially uniform thickness T _1. Further, as shown in FIG. 4C, a winding is wound around the core 40 along the ring of the core 40 to form a toroidal coil 42. The coil 42 is wound around the core 40 with a substantially uniform density, and the output of the coil 42 is taken out from the output portions 43 at both ends.

In the second embodiment, the primary conductors 41 </ b> R, 41 </ b> S, 41 </ b> T are linearly arranged apart from each other in the through hole of the core 40. In the case of such an arrangement, the widths W ₆ and W ₈ at the positions of both ends in the longitudinal direction of the core 40 according to the displacement in the longitudinal direction of the primary conductors 41R and 41T from the core center are set to the central portion close to the core center. It is made larger than the widths W ₅ and W ₇ of the position of. Here, in each part of the core 40, the larger the displacement from the core center of the primary conductor in the vicinity (L ₃ , L _{4 in} FIG. 2A) is, the wider the width of the core of the corresponding part is from the part at the symmetrical position. Also make it bigger. That is, since the primary conductors 41R and 41T are offset from the center of the core by L ₃ and L ₄ respectively, the width of the core 40 is set in accordance with the amount of displacement. By configuring the core 40 in this manner, the magnetic characteristics of the coil and the core with respect to the primary conductor can be made equivalent at all positions, and the magnetic flux imbalance caused by the position on the core can be reduced. Detection can be suppressed.

(Third embodiment)
FIG. 5 is a diagram showing a main configuration of a leakage detecting apparatus according to the third embodiment of the present invention. 5A is a perspective view of the core and the primary conductor of the leakage detection device, FIG. 5B is a plan view of the core viewed from a direction perpendicular to the ring of the core, and FIG. 5C is a plan view of the core and the coil. Each is shown.

As shown in FIGS. 5A and 5B, the core 50 is formed in an oval shape, and three primary conductors 51 </ b> R, 51 </ b> S, and 51 </ b> T through which a three-phase primary current flows through the core 50 pass through. Are arranged. The primary conductors 51R, 51S, 51T are arranged in a straight line in the longitudinal direction of the through hole of the oval core 50, and the primary conductors 51R, 51T are symmetrically arranged around the primary conductor 51S. The thickness of the core 50 is assumed to be uniformly formed at T _1. As shown in FIG. 5C, the core 50 has a toroidal coil 52 formed by winding a winding around the core 50. The coil 52 is wound around the core 50 with a substantially uniform density, and the output of the coil 52 is taken out from the output portions 53 at both ends.

In the third embodiment, the primary conductors 51R and 51T are arranged symmetrically at the position of the displacement a across the primary conductor 51S of the core center. In such an arrangement, the primary conductors 51R, depending on the longitudinal displacement of the center of the core 51T, the width W ₁₀ of the curved portion of the longitudinal ends of the core 50, the width W of the linear portion of the core center side Make it larger than ₉ . Here, the width W ₁₀ of the curved portion of the core 50, the larger the displacement a from the core center of the primary conductor in the vicinity, larger than the width W ₉ of the linear portion. By configuring the core 50 in this way, the magnetic characteristics of the coil and the core with respect to the primary conductor can be made equivalent at all positions, and the magnetic flux imbalance caused by the position on the core can be reduced. Detection can be suppressed. Further, by arranging the primary conductors 51R, 51S, and 51T symmetrically, the primary conductors can be configured linearly with the same shape, and therefore can be configured at low cost. Further, by providing symmetry in the arrangement of the primary conductors 51R, 51S, and 51T, the cross-sectional area of the core, for example, the core width can be reduced in each of the curved portion in the longitudinal direction and the straight portion in the short direction of the core 50. Since it can be made the same and the balance characteristic can be improved, it is possible to suppress erroneous detection of leakage in a balanced state.

(Fourth embodiment)
FIG. 6 is a diagram showing a main configuration of a leakage detecting apparatus according to the fourth embodiment of the present invention. FIG. 6 shows a plan view of the core of the leakage detection device as viewed from a direction perpendicular to the core ring.

  The core 60 is formed in an oval shape, and three primary conductors 61R, 61S, and 61T through which a three-phase primary current flows are disposed through the through hole of the core 60. The primary conductors 61R, 61S, 61T are arranged in a straight line in the longitudinal direction of the through hole of the oval core 60, and the primary conductors 61R, 61T are symmetrically arranged at the position of the displacement a across the primary conductor 61S. . Although not shown here, the coils and the like are configured in the same manner as in the third embodiment. The thickness of the core 60 is assumed to be uniformly formed at T1.

In the fourth embodiment, the curved portion of the longitudinal ends of the core 60, and the straight portion of the core center side, are uniformly formed with a width W _11. Then, the connection portion from the straight portion to the curved portion of the core 60, constituted by clothoid curve of width greater than the width W ₁₁ of the straight portions and curved portions. That is, at the connection portion, when the clothoid curve length of the outer section is L _K1 , the clothoid curve length of the inner section is L _K2 , the outer curvature radius is R _K1 , and the inner curvature radius is R _K2 ,
L _K1 R _K1 = constant L _K2 R _K2 = constant.

  In this way, the cross-sectional area of the core is non-uniform by configuring the longitudinal direction of the elliptical core as a straight line portion and both ends thereof as curved portions, and configuring these connecting portions with a clothoid curve wider than the straight portion. Thus, the magnetic flux imbalance can be reduced. Moreover, positioning can be facilitated by having a straight portion in the core. In addition, by smoothly changing the cross-sectional area using the clothoid curve, the corner of the connecting part that transitions from the straight part to the curved part is eliminated, so when winding the coil directly around the core of this part, Winding can be facilitated, and assemblability can be improved.

(Fifth embodiment)
FIG. 7 is a diagram showing a main configuration of a leakage detection apparatus according to the fifth embodiment of the present invention. 7, (a) is a plan view of the core of the leakage detection device as viewed from a direction perpendicular to the core ring, (b) is a side view of the core viewed from the side, and (c) is a plan view of the core and the coil. Respectively.

  As shown in FIGS. 7A and 7C, the core 70 is configured in an oval shape, and three primary conductors 71 </ b> R, 71 </ b> S, 71 </ b> T through which a three-phase primary current flows are passed through the through-holes of the core 70. Are arranged. The primary conductors 71R, 71S, 71T are arranged in a straight line in the longitudinal direction of the through hole of the oval core 70, and the primary conductors 71R, 71T are symmetrically arranged at the position of the displacement a with the primary conductor 71S interposed therebetween. .

As shown in FIG. 7 (b), the core 70 is a soft magnetic material are stacked, is formed in a substantially uniform thickness T _1. Further, as shown in FIG. 7C, a winding is wound around the core 70 along the ring of the core 70 to form a toroidal coil 72. The coil 72 is wound around the core 70 with a substantially uniform density, and the output of the coil 72 is taken out from the output portions 73 at both ends.

In the fifth embodiment, both the width W ₁₂ and the thickness T _{1 of} the core 70 are uniformly formed, and the notches 75 are formed in the curved portions at both ends in the longitudinal direction of the core 70. As described above, when the primary conductors 71R and 71T are displaced and separated from the primary conductor 71S in the center of the core, the longitudinal direction in which the core 70 is close to the primary conductor and becomes a portion where the magnetic flux is concentrated. Notches 75 are provided in the curved portions at both ends. That is, instead of increasing the width of the core as in the third embodiment or the like, by providing a notch in the corresponding portion, the magnetic permeability is partially reduced and the magnetic flux unbalance is reduced.

  FIG. 8 is a diagram showing a modification of the fifth embodiment. In the modification of FIG. 8, slits 85 are formed in the circumferential direction of the core 80 at the curved portions at both ends in the longitudinal direction of the core 80 instead of the notch 75 of FIG. 7. Even when such a slit 85 is provided, the same effect as the notch 75 can be obtained.

  Thus, by providing a notch or a slit in the portion where the magnetic flux concentrates in the core having a substantially uniform cross-sectional area, the magnetic permeability can be partially reduced and the magnetic flux passing through the core can be kept uniform. Thereby, the imbalance of the magnetic flux produced by the position on a core can be reduced, and the misdetection of an electrical leakage can be suppressed. Further, when the cutout is provided, when the coil is wound directly around the core, the cutout can be utilized for the electric wire holding portion of the coil, so that the coil can be easily wound and the assemblability can be improved.

(Sixth embodiment)
FIG. 9 is a diagram showing a main configuration of a leakage detecting apparatus according to the sixth embodiment of the present invention. 9, (a) is a plan view of the core of the leakage detection device as seen from a direction perpendicular to the core ring, (b) is a side view of the core as seen from the side, and (c) is a plan view of the core and the coil. Respectively.

  As shown in FIGS. 9A and 9C, the core 90 is formed in an oval shape, and three primary conductors 91 </ b> R, 91 </ b> S, and 91 </ b> T through which a three-phase primary current flows through the through-hole of the core 90 penetrate. Are arranged. The primary conductors 91R, 91S, 91T are arranged in a straight line in the longitudinal direction of the through hole of the oval core 90, and the primary conductors 91R, 91T are symmetrically arranged around the primary conductor 91S. Further, as shown in FIG. 9C, the core 90 has a toroidal coil 92 formed by winding a winding on the outside along the ring of the core 90. The coil 92 is wound around the core 90 with a substantially uniform density, and the output of the coil 92 is taken out from the output portions 93 at both ends.

In the sixth embodiment, as shown in FIG. 9A, the width of the core 90 is substantially uniform with the width w. Then, as shown in FIG. 9 (b), the core 90 is a soft magnetic material are laminated, formed in the longitudinal direction of the straight portions substantially uniform thickness T ₁ of the core 90 of oval Has been. Then, the curved portion of the both end portions of the core 90, the thick portion 95 and T _{1 +} T _alpha thickness by increasing the stacking number as large as T _alpha is formed. As described above, when the primary conductors 91R and 91T are displaced and separated from the primary conductor 91S in the center of the core, the longitudinal direction in which the distance from the primary conductor is close and the magnetic flux is concentrated in the core 90. The thickness is increased with the curved portions at both ends as the thick portions 95. That is, instead of increasing the width of the core as in the third embodiment, the cross-sectional area of the core of the magnetic flux concentration portion is increased by increasing the thickness of the corresponding portion, and the magnetic flux unbalance is reduced. To reduce. Thereby, the imbalance of the magnetic flux produced by the position on a core can be reduced, and the misdetection of an electrical leakage can be suppressed.

(Seventh embodiment)
FIG. 10 is a diagram showing a main configuration of a leakage detection apparatus according to the seventh embodiment of the present invention. 10, (a) is a perspective view of a core, a coil, and a primary conductor of a leakage detecting device, and (b) to (e) are exploded perspective views in a state where each substrate constituting the core and the coil is disassembled.

  The seventh embodiment shows a configuration example in which a configuration substantially similar to that of the third embodiment shown in FIG. 5 is formed by a substrate. As shown in FIG. 10A, the printed circuit board 104 includes a core 100 having an elliptical shape and a non-uniform cross-sectional area, and windings are formed outside the core 100 along the ring of the core 100. A toroidal coil 102 is formed so as to be wound. Three primary conductors 101R, 101S, and 101T through which a three-phase primary current flows are disposed through the through hole of the core 100. The primary conductors 101R, 101S, and 101T are arranged in a straight line in the longitudinal direction of the through hole of the elliptical core 100, and the primary conductors 101R and 101T are arranged symmetrically around the primary conductor 101S. The printed circuit board 104 is mounted with electronic components 105 constituting a detection circuit connected to the output units 103 at both ends of the coil 102.

  As shown in FIGS. 10B, 10C, and 10D, the printed circuit board 104 on which the core 100 and the coil 102 are formed is configured by a stacked substrate in which three substrates 104a, 104b, and 104c are stacked. ing. These substrates 104a, 104b, and 104c are provided with circuit patterns 106 and through holes 107 corresponding to the arrangement of the coils 102 so as to surround the outside of the core 100. The coil 102 is formed. Here, the coil 102 is formed with a substantially uniform winding density. At this time, the circuit patterns 106 and the through holes 107 are formed on the outer surface of the substrates 104a and 104c on the outer layer, and the through holes 107 are formed so as to penetrate to the other surface. Further, a through hole 107 is formed in the inner layer substrate 104b so as to penetrate both surfaces. As shown in FIG. 10E, the inner layer substrate 104b sandwiched between the substrates 104a and 104c has a structure in which a core 100 of soft magnetic material is interposed between the outer substrate 104d and the inner substrate 104e. It has become. For example, the substrate 104b is formed as a single plate by sequentially arranging the core 100 and the inner substrate 104e in the opening formed in the central portion of the outer substrate 104d, and for passing through the primary conductor in the central portion of the inner substrate 104e. It can be produced by forming a through-hole.

  In the above configuration, the elliptical core 100 built in the printed circuit board 104 has the widths of the curved portions at both ends in the longitudinal direction of the core 100 according to the displacement in the longitudinal direction from the core center of the primary conductors 101R and 101T that penetrate therethrough. The width is larger than the width of the straight portion on the core center side. Here, the thickness of the core 100 is formed substantially uniformly by the laminated substrate. In this way, the non-circular core and coil are formed by incorporating the core 100 having a non-uniform cross-sectional area in the printed circuit board 42 of the laminated substrate in which the coil 102 is formed by the circuit pattern 106 and the through hole 107. It becomes easy to do. In this case, the coil can be easily wound around the entire circumference along the substantially oval core ring. Further, by forming the core 100 and the coil 102 with the printed circuit board 104, coil winding variation can be eliminated, and the detection accuracy and assembly accuracy of the zero-phase current transformer in the leakage detector can be improved.

(Eighth embodiment)
FIG. 11 is a diagram illustrating a configuration of a main part of a leakage detection device according to the eighth embodiment of the present invention, and FIG. 12 is a block diagram illustrating a configuration of the leakage detection device according to the eighth embodiment. The eighth embodiment shows a configuration example of a leakage detection device according to the present invention. In the present embodiment, a substantially elliptical zero-phase current transformer 120 having a core and a coil configured as in each of the above-described embodiments is provided.

  As shown in FIG. 11, the zero-phase current transformer 120 is provided with substantially elliptical through-holes corresponding to the primary conductors 111R, 111S, and 111T of a plurality of electric circuits connected from the AC power source to the load device. To be provided. The primary conductors 111R, 111S, and 111T are each formed in a straight line except for the terminal portion in order to simplify the structure and improve the assemblability, and these are arranged in a line substantially in parallel. The conductors 111 </ b> R, 111 </ b> S, and 111 </ b> T have a structure that penetrates the through-hole of the zero-phase current transformer 120. Here, the primary conductors 111R, 111S, and 111T are formed and provided in a substantially constant state so that the distance between the conductors does not change in the region before and after the through-hole of the zero-phase current transformer 120. . That is, the primary conductors 111R, 111S, and 111T have a simple shape that is substantially straight without a bent portion or the like, and are arranged in parallel in the longitudinal direction of the through-hole of the zero-phase current transformer 120.

  Further, current detectors 112, 113, and 114 are provided corresponding to the respective primary conductors 111R, 111S, and 111T, and the primary conductor passes through each current detector. In the example of FIG. 11, current detectors 112, 113, and 114 are arranged on a circuit board 118 provided in the vicinity of the zero-phase current transformer 120, and further, current detectors 112, 113, and 114 are arranged on the circuit board 118. Signal processing circuits 115, 116, and 117 that perform signal processing such as amplification on the outputs are provided. Here, the current detectors 112, 113, and 114 can be configured by forming a coil on the circuit board 118 with a circuit pattern and a through hole.

  Further, as shown in FIG. 12, the analog output signals of the signal processing circuit 121 and the signal processing circuits 115, 116, 117, and 121 that perform amplification and filtering of the output of the zero-phase current transformer 120 are converted into digital signals. / D converters 122 to 125, a leakage current detection circuit 126, and an output terminal 127 are provided. The leakage current detection circuit 126 compares these output values with predetermined values using the digital signals from the A / D converters 122 to 125, determines whether or not there is a leakage state, and outputs a leakage detection signal to the output terminal 127. To do.

  The circuit breaker contact 128 of the switch is provided in the electric circuit of the AC power supply input unit, and the leakage detection signal output from the leakage current detection circuit 126 is supplied from the output terminal 127 to the circuit breaker contact 128. When a leakage state is detected in the leakage detection device, the circuit to the load is interrupted at the circuit breaker contact 128 of the switch based on the leakage detection signal. Further, as a switch, when a predetermined overcurrent is detected in the electric circuit, the circuit circuit breaker contact 128 interrupts the electric circuit to the load.

  In the earth leakage detection device and switch equipped with such a zero-phase current transformer 120, by appropriately setting the cross-sectional area of the core depending on the position, the magnetic flux imbalance generated in the substantially oval core is reduced. It is possible to suppress erroneous detection of leakage. In this case, since the core of the zero-phase current transformer 120 has a substantially oval shape, it is possible to increase the penetrating area through which the primary conductor penetrates, compared to a general circular shape. As a result, it is not necessary to bend the primary conductor in order to reduce the distance between the electric circuits in the portion of the container, and the assemblability is greatly improved.

  In each of the embodiments described above, the core of the leakage detection device can be configured without increasing the size of the device by making the core of the leakage detection device into a substantially oval shape having a longitudinal direction and a short direction, and without bringing the primary conductor close to the core. By arranging, the electric circuit shape for each phase can be made the same, the assemblability can be improved, the temperature rise can be reduced, and the problems in cost and performance can be eliminated. That is, it is possible to realize a leakage detecting device that is small and inexpensive and that can reduce temperature rise. At this time, due to the substantially oval core structure and the arrangement in which the primary conductors are separated from each other, erroneous detection of leakage may occur when the primary current is in an equilibrium state. However, the cross-sectional area of the core varies depending on the position. By setting appropriately, the magnetic characteristics of the core and the coil can be made uniform. Thereby, erroneous detection of the leakage detection device can be reduced, and detection accuracy can be improved.

  The present invention is intended to be variously modified and applied by those skilled in the art based on the description in the specification and well-known techniques without departing from the spirit and scope of the present invention. Included in the scope for protection.

10, 20, 30, 40, 50, 60, 70, 80, 90, 100 Core 11a, 11b, 21a, 21b, 21c, 31R, 31S, 31T, 41R, 41S, 41T, 51R, 51S, 51T, 61R, 61S, 61T, 71R, 71S, 71T, 91R, 91S, 91T, 101R, 101S, 101T, 111R, 111S, 111T Primary conductors 32, 42, 52, 72, 92, 102 Coils 33, 43, 53, 73, 93 , 103 Output part 35 Circuit board 36 Detection circuit 37 Power supply 75 Notch 85 Slit 95 Thick part 104 Printed circuit board 104a, 104b, 104c Board 104d Outer board 104e Inner board 105 Electronic component 106 Circuit pattern 107 Through hole 112, 113, 114 Current detector 115, 116 117 and 121 signal processing circuit 118 circuit board 120 ZCT 122 to 125 A / D converter 126 leakage current detecting circuit 127 output terminal 128 circuit breaker contacts

Claims (5)

A core made of a substantially elliptical magnetic material having a long side and a short side, the radial dimension of which varies depending on the position, and is a ring that penetrates a plurality of primary conductors inward;
A toroidal coil in which a winding is wound along the ring of the core;
A detection unit for detecting an output voltage due to an induced voltage generated in the coil,
The core is formed non-uniformly so that the cross-sectional area varies depending on the circumferential position of the ring of the core, the cross-sectional area of the portion that intersects the short side is different from the cross-sectional area of the portion that intersects the long side,
Furthermore, the core is
It has a linear portion extending in the longitudinal direction, and a curved portion connecting both ends of the straight portion,
In the connecting portion between the straight line portion and the curved portion, the outline in plan view has a first clothoid curve on the inner side that is the center side of the core and a second outer surface that is opposite to the center side of the core. And a clothoid curve portion determined by:
The clothoid curve portion is formed is substantially uniform thickness, and width determined by the distance between the first clothoid curve and the second clothoid curve, than the width of the end portion of the straight portion In addition, the leakage detecting device has a larger width at the end opposite to the linear portion . The leakage detection device according to claim 1,
When a plurality of primary conductors pass through the inside of the core and three primary conductors are arranged in a line in the longitudinal direction of the substantially oval core, one of the primary conductors is the core center of the core The earth leakage detection device is arranged so that the other two are located symmetrically with the core center portion in between. The leakage detection device according to claim 1,
The core is configured to be embedded in a substrate, and the toroidal coil is formed on the substrate by a circuit pattern and a through-hole, and a winding is wound around the core along the ring of the core. Earth leakage detection device. A ring that penetrates a plurality of primary conductors inward, a radial dimension varies depending on the position, a core made of a substantially oval magnetic material having a long side and a short side, and a ring of the core A method of forming a core of a leakage detection device comprising a toroidal coil around which a winding is wound and a detection unit for detecting an output voltage due to an induced voltage generated in the coil,
The core is non-uniformly formed so that the cross-sectional area differs depending on the circumferential position of the ring of the core, the cross-sectional area of the portion that intersects the short side is different from the cross-sectional area of the portion that intersects the long side ,
And, the core has a linear portion extending in the longitudinal direction, and a curved portion connecting both ends of the linear portion, and in the connecting portion between the linear portion and the curved portion, the contour in plan view is A clothoid curve portion determined by an inner first clothoid curve that is the center side of the core and an outer second clothoid curve that is the opposite side to the center side of the core is provided, and the clothoid curve portion Has a substantially uniform thickness, and the width determined by the distance between the first clothoid curve and the second clothoid curve is greater than the width of the end portion on the straight portion side. Construct so that the width of the end opposite to the part side is larger,
In a state where a plurality of primary conductors are passed through the inside of the core and are arranged side by side in the longitudinal direction of the substantially oval core, the equilibrium position in a state where the plurality of primary conductors are closely arranged in the center of the core As a reference, when one arrangement position of the plurality of primary conductors is displaced, a sectional area of a portion where the distance from the primary conductor where the displacement occurs due to the displacement is reduced, and the distance is increased by the displacement. A method for forming a core of a leakage detection device, wherein the core is formed to be larger than a cross-sectional area of the portion to be formed. A method for forming a core of a leakage detection device according to claim 4 ,
The core, the higher the amount of displacement from the equilibrium position of the primary conductor displacement occurs is large, larger forming distance is a cross-sectional area near it becomes part of the primary conductor in which the displacement occurs, forming the core of the leakage detecting device Method.

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