JP5557308B2 - Electric leakage detection device and method of arranging coils 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 coil comprises one or more of the pair A portion having a high winding density is provided , and each of the pair of high winding densities is in a line-symmetric position with respect to a long side of the core, and the one or more pairs of winding densities are One of the high portions provides a leakage detection device in which the short side of the core is at a position where it intersects the core .
With the above structure, the core as a substantially oval shape, even when the miniaturization easy assembly of the device has a good structure, occurs in the coil when the imbalance of the magnetic flux is caused by the position of the core The imbalance of the induced voltage can be reduced. 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.

Moreover, this invention is said leakage detection apparatus, Comprising: As for a part with said high winding density, one or several each line segment obtained by connecting each and the long side of the said core cross | intersect, 1 One of the one or a plurality of intersections includes one disposed so as to be positioned between two adjacent primary conductors in a state where a plurality of primary conductors are penetrated inside the core .

Further, the present invention is the above leakage detection apparatus, wherein an intersection of a long side and a short side of the core is set as a center point of the core, and the center point of the core is sandwiched between the long side and the core. Each of two points that are symmetrical with respect to the center point is defined as a first point and a second point, and a perpendicular bisector connecting the first point and the second point intersects the core 2 When each of the points is a first intersection and a second intersection, the winding density of the coil at the first intersection and the vicinity thereof, and the winding density of the coil at the second intersection and the vicinity thereof, In a state where the winding density of the other part of the core is set higher than that of the core and a plurality of primary conductors are passed through the core, the two adjacent primary conductors are connected to the first primary conductor and the second primary conductor. When a conductor is used, the first primary conductor is within the core, The second primary conductor is disposed at or near the first point, and the second primary conductor is disposed at or near the second point in the core, and the direction of the current flowing through the first primary conductor, The direction of the current flowing through the two primary conductors includes a reverse direction .

Further, the present invention is the above leakage detection apparatus, wherein the first intersection and its vicinity, and the second intersection and its vicinity are currents flowing through the first primary conductor and the second primary conductor, respectively. Includes a portion in which the magnetic flux density in a balanced state is sparser than the other portions of the core .

  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 block diagram which shows the structure of the leak detection apparatus which concerns on 5th 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 shown in a simplified manner.

  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 this embodiment, the winding density of the coil is varied depending on the position, and the balance of magnetic characteristics in the core and the coil is adjusted by setting the winding density of the coil. Thereby, the imbalance of the induced voltage which arises in a coil when the imbalance of magnetic flux arises with the position of the core can be reduced. That is, based on the positional relationship between the core and coil and the primary conductor, the coil winding density is set so that the magnetic properties (magnetic resistance) of the coil and core relative to the primary conductor are equivalent at any position regardless of position. To do. Thereby, an equivalent magnetic circuit is formed at all positions on the core.

  In the example of FIG. 1, the winding density of the coils 12 and 22 is not uniform and differs depending on the positional relationship between the substantially elliptical cores 10 and 20 and the primary conductors 11a, 11b, 21a, 21b, and 21c. To do. That is, depending on the distances between the cores 10 and 20 and the coils 12 and 22 and the primary conductors 11a, 11b, 21a, 21b, and 21c, different winding densities are set depending on the positions on the core.

  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. Occurs. 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, the winding density of the coil located between the two primary conductors where the magnetic flux is not concentrated is increased so as to keep the balance of the magnetic characteristics. Specifically, the winding density at the middle portion of the two primary conductors is increased by densely winding the winding at the intersection with the core on the vertical bisector that connects the centers of the two primary conductors. . In other words, the winding density of the coils 12 and 22 in the portion where the magnetic fluxes of the cores 10 and 20 are sparser than the others is higher than the others in the position sandwiched between the primary conductors 11a, 11b, 21a, 21b and 21c. The detection sensitivity of the coils 12 and 22 in this portion is increased.

  That is, in the case of FIG. 1A, the winding density of the coil portions 12a and 12b located between the primary conductors 11a and 11b is increased. Similarly, in the case of FIG. 1B, the winding density of the coil portions 22a, 22b, 22c, and 22d located between the primary conductors 21a, 21b, and 21c is increased.

  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 coil winding density so as to differ depending on the position, it is possible to reduce the unbalance of the induced voltage generated in the coil when the unbalance of the magnetic flux occurs due to the position of the core. It is possible to improve the detection accuracy by suppressing erroneous detection while reducing the size of the devices constituting the detection device and making the assembly easy.

(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 FIGS. 2A and 2B, the core 30 is formed by laminating soft magnetic materials, and has a substantially uniform width W ₁ and 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. Then, the output of the coil 32 is taken out from the output portions 33 at both ends of the coil 32.

  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, and the winding of the coil 32 is uniformly wound and the winding density is uniform, the magnetic flux of the entire core is unbalanced even when the primary current is in a balanced state. An induced voltage is generated in the coil 32, and the output voltage is detected in the output unit 33, which may cause erroneous detection of leakage.

Therefore, in the present embodiment, the winding density of the coil 32 is unevenly formed so as to vary depending on the position according to the positional relationship between the core 30 and the coil 32 and the primary conductors 31R, 31S, and 31T. Thereby, the imbalance of the induced voltage generated in the coil 32 is eliminated. Specifically, in FIG. 2A, the winding density K of the coil 32 at the intersection with the core on the perpendicular bisector that connects the centers of the two primary conductors of the primary conductors 31R, 31S, and 31T. _5, to increase the _{K 6, K 7, K 8} .

In this case, since the magnetic flux tends to concentrate in a portion where the distance between the core 30 and the primary conductors 31R, 31S, and 31T is short, the winding densities K ₁ , K ₂ , K ₃ , and K ₄ in this portion are reduced. The winding densities K ₅ , K ₆ , K ₇ , and K ₈ in other portions are increased. That is, the winding density is increased by densely winding the winding corresponding to the portion where the magnetic flux between the primary conductors 31R, 31S, and 31T is not concentrated. By configuring the coil 32 in this way, an equilibrium state of magnetic flux can be created equivalently, and a detection output can be prevented from being output when the current flowing through the primary conductors 31R, 31S, 31T is in an equilibrium state. Thereby, the magnetic characteristics of the coil and the core with respect to the primary conductor can be made equivalent at all positions, and the imbalance of the induced voltage generated in the coil can be reduced, so that erroneous detection of leakage can be suppressed.

  FIG. 2D is a diagram showing a modification of setting the winding density of the coil 32. As in the example of FIG. 2D, the winding density of the coil 32 can be changed stepwise, and the winding density of each part can be set as appropriate.

  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 detection circuit 36 formed of an IC or the like on which a resistor R1 that matches the characteristic impedance Z1 of the coil 32, a circuit that detects the output voltage of the coil 32, and the like, and the coil 32 A reference resistor R2 for comparing the output voltages of the two 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 FIGS. 4A and 4B, the core 40 is formed by stacking soft magnetic materials, and is formed to have a substantially uniform width W ₂ and 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. Then, the output of the coil 42 is taken out from the output portions 43 at both ends of the coil 42.

In the second embodiment, in the configuration in which the primary conductors 41R, 41S, and 41T are arranged in a line in the longitudinal direction of the core 40, the vertical bisector that connects the centers of the two primary conductors of the primary conductors 41R, 41S, and 41T. The winding density K ₅ , K ₆ , K ₇ , K ₈ of the coil 42 is increased at the intersection with the core on the line. In this case, by arranging the primary conductors 41R, 41S, and 41T in a straight line in the longitudinal direction of the core 40, the winding density of the coil 42 becomes K ₅ = K ₆ and K ₇ = K ₈ . With such a configuration, it is possible to reduce the imbalance of the induced voltage generated in the coil 42 when the magnetic flux is unbalanced depending on the position on the substantially elliptical core 40, and to suppress erroneous detection of leakage.

(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 core 50 is substantially uniformly formed with a width W _3, assumed to be substantially uniformly formed also thick. As shown in FIG. 5C, the core 50 has a toroidal coil 52 formed by winding a winding around the core 50. Then, the output of the coil 52 is taken out from the output portions 53 at both ends of the coil 52.

In the third embodiment, in the configuration in which the primary conductors 51R and 51T are symmetrically arranged at the position of the displacement a across the primary conductor 51S of the core, the centers of the two primary conductors of the primary conductors 51R, 51S and 51T. The winding density K ₅ , K ₆ , K ₇ , K ₈ of the coil 52 is increased at the intersection with the core on the perpendicular bisector connecting In this case, the primary conductor 41S other primary conductor 41R around a, by arranging symmetrically 41T, a uniform winding density _K 5 ~K ₈ of the coil 52 as _{K 5 = K 6 = K 7} = K 8 be able to. With such a configuration, it is possible to reduce the imbalance of the induced voltage generated in the coil 52 when the magnetic flux is unbalanced depending on the position on the substantially elliptical core 50, and to suppress erroneous detection of leakage. 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.

(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. In FIG. 6, (a) is a perspective view of the core, coil and primary conductor of the leakage detection device, and (b) to (e) are exploded perspective views in a state where each substrate constituting the core and coil is disassembled.

  The fourth 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. 6A, the printed circuit board 104 includes a core 100 having an oval shape and a substantially 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. 6B, 6C, and 6D, the printed circuit board 104 on which the core 100 and the coil 102 are formed is configured by a laminated board in which three boards 104a, 104b, and 104c are laminated. 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. 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. 6E, 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 coil 102 formed on the printed circuit board 104 increases the winding density at the intersection point with the core on the perpendicular bisector that connects the centers of the two primary conductors of the primary conductors 101R, 101S, and 101T. . That is, the winding density is increased at the position of the intermediate portion between the primary conductors 101R and 101S and between the primary conductors 101S and 101T, and the winding density is different depending on the position. In this way, by incorporating the core 100 in the printed circuit board 42 of the multilayer substrate in which the coil 102 is formed by the circuit pattern 106 and the through hole 107, a coil having a non-uniform winding density is formed on a non-circular core. It becomes easy to do. In this case, a coil having an appropriate winding density can be easily wound around the entire circumference along a 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.

(Fifth embodiment)
FIG. 7 is a diagram showing a main part configuration of a leakage detection apparatus according to the fifth embodiment of the present invention, and FIG. 8 is a block diagram showing a configuration of the leakage detection apparatus according to the fifth embodiment. The fifth 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. 7, the zero-phase current transformer 120 is provided with substantially elliptical through holes corresponding to the primary conductors 111 </ b> R, 111 </ b> S, 111 </ b> T 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. 7, 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 the current detectors 112, 113, and 114 are further 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. 8, 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 leakage detecting device and switch equipped with such a zero-phase current transformer 120, magnetic flux imbalance occurs in the substantially elliptical core by appropriately setting the winding density of the coil depending on the position. In this case, the imbalance of the induced voltage generated in the coil can be reduced, and erroneous detection of leakage can be suppressed. 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 elliptical core structure and the arrangement in which the primary conductors are separated from each other, an erroneous detection of leakage may occur when the primary current is in an equilibrium state, but the winding of the coil wound around the core The magnetic properties of the core and the coil are made uniform by increasing the winding density at the intersection with the core on the perpendicular bisector that connects the centers of the two primary conductors so that the density varies depending on the position. Can be 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, 100 Cores 11a, 11b, 21a, 21b, 21c, 31R, 31S, 31T, 41R, 41S, 41T, 51R, 51S, 51T, 101R, 101S, 101T, 111R, 111S, 111T Primary conductor 32, 42, 52, 102 Coil 33, 43, 53, 103 Output unit 35 Circuit board 36 Detection circuit 37 Power supply 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, 121 Signal processing circuit 118 Circuit board 120 Zero phase current transformer 122-125 A / D converter 126 Leakage current detection circuit 127 Output end 128 Circuit breaker contact

Claims (6)

Is of 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,
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,
It said coil is one or more of the pair of winding density is high portion is provided,
Each of the pair of high winding density portions is in a line-symmetric position with respect to the long side of the core, and one of the one or more pairs of high winding density portions is the An earth leakage detection device having a short side of the core at a position where the core intersects the core . The leakage detection device according to claim 1,
The pair of portions having a high winding density has one or more intersections where one or more line segments obtained by linking each of the portions and the long sides of the core intersect each other, In a state where a plurality of primary conductors are passed through, a leakage detecting device is disposed so as to be positioned between two adjacent primary conductors . The leakage detection device according to claim 2 ,
The intersection of the long side and the short side of the core is the center point of the core,
On the long side, the center point of the core is sandwiched, and two points that are symmetrical with respect to the center point of the core are defined as a first point and a second point,
In the case where each of the two points where the perpendicular bisector of the line segment connecting the first point and the second point intersects the core is the first intersection and the second intersection,
The winding density of the coil at and near the first intersection and the winding density of the coil at and near the second intersection are set higher than the winding density of the other parts of the core,
In a state where a plurality of primary conductors are passed through the inside of the core, when the two adjacent primary conductors are a first primary conductor and a second primary conductor,
The first primary conductor is disposed in the core at or near the first point,
The second primary conductor is disposed in the core at or near the second point, and the direction of the current flowing through the first primary conductor is opposite to the direction of the current flowing through the second primary conductor. Earth leakage detection device that is oriented . The leakage detection device according to claim 3 ,
The first intersection and the vicinity thereof, and the second intersection and the vicinity thereof have a magnetic flux density when the current flowing through each of the first primary conductor and the second primary conductor is balanced, Leakage detection device that is a part that is sparser than the part . 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 arranging a coil 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 coil is provided with one or a plurality of a pair of high winding density portions, and each of the pair of high winding density portions is in a line-symmetrical position with respect to the long side of the core, One of the one or more pairs of high winding density portions is located at a position where the short side of the core intersects the core, and the pair of high winding density portions are connected to each other. One or more intersecting points at which one or more obtained line segments intersect with the long side of the core are adjacent to each other in a state where a plurality of primary conductors are penetrated inside the core. A method of arranging a coil of a leakage detection device, which is arranged so as to be positioned between two primary conductors. A method of arranging a coil of the leakage detection device according to claim 5,
The intersection of the long side and the short side of the core is the center point of the core, and on the long side, the center point of the core is sandwiched, and each of the two points that are symmetrical with respect to the center point of the core, When the first point and the second point are used, and each of the two points where the perpendicular bisector of the line connecting the first point and the second point intersects the core is defined as the first point and the second point In
The winding density of the coil at and near the first intersection and the winding density of the coil at and near the second intersection are set higher than the winding density of the other parts of the core,
In a state where a plurality of primary conductors are penetrated inside the core, when the two adjacent primary conductors are a first primary conductor and a second primary conductor, the first primary conductor is the core. The first primary conductor is disposed at or near the first point, and the second primary conductor is disposed at or near the second point in the core, and the direction of the current flowing through the first primary conductor is The method of arranging the coils of the leakage detecting device, wherein the direction of the current flowing through the second primary conductor is reversed.

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