JPH0643189A - Current measuring device - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a current measuring instrument with high measurement accuracy when measuring the current of the busbar by the induced voltage of the coil. [Structure] Split coils 4 ₁ to 4 ₁₂ are formed by winding a predetermined number of turns around the outer peripheral surface of a cylindrical core. Voltage adjusting terminals 9 _{1 to} 9 ₁₂ are provided in the vicinity of the winding ends of the split coils 4 ₁ to 4 ₁₂ . Further, these split coils 4 ₁ to 4 ₁₂ are arranged on a plane perpendicular to the axis of the busbar 1 such that the central axis is the same as the tangent of a circle whose center is the axis of the busbar 1. Are arranged at the same distance at equal intervals with respect to the axis center of and are connected in series.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current measuring device for measuring a current flowing through a bus bar by an induced voltage in a coil.

[0002]

2. Description of the Related Art FIG. 12 is a front view showing an example of a conventional current measuring device shown in, for example, the Handbook of Electrical Engineering (The Institute of Electrical Engineers of Japan, reprinted on October 30, 1982), and FIG.
14 is a sectional view taken along line XIII-XIII in FIG. 14, FIG. 14 is a front view showing a winding state of the conventional current measuring device of FIG. 12, and FIG.
FIG. 6 is a characteristic diagram showing an induced voltage due to another bus line in FIG.

In these figures, 1 is a busbar through which a current to be measured flows, 2 is an insulating core having an annular shape surrounding the outer periphery of the busbar, 3 is a coil wound around the core 2, 3a, Three
Each of b is a coil terminal of the coil 3, and the voltage of the coil terminals 3a and 3b is measured to measure the current flowing through the bus 1. Further, 11 is another bus bar provided near the current measuring device.

Next, the operation of the conventional current measuring device will be described. The coil 3 is generated by the current I flowing through the bus 1.
A magnetic field H is generated inside. The relationship between the current I, the magnetic field H, and the magnetic flux density B is expressed by (Equation 1) below. I = ∫H · dL = ∫ (B / μ ₀ ) · dL (Equation 1)

A current I flowing through the bus bar 1 is a sine wave alternating current with an angular frequency ω, a minute length of the coil 3 in the circumferential direction of the bus bar is ΔL, the number of turns between them is N, and an interlinking cross-sectional area interlinking with a magnetic field H of the coil 3 Is S, the magnetic flux interlinking with the coil 3 is Φ, the magnetic permeability of the vacuum is μ ₀ , and the induced voltage is e, then I = Σ {Φ · ΔL / (μ ₀ S)} | I | = ΔL · Σ {e / (N · μ ₀ · S · ω)} (Equation 2) is obtained.

N / ΔL is the winding density n in the circumferential direction, which is constant, the cross-sectional area of the interlinkage is constant in the circumferential direction, and the induced voltage between the coil terminals 3a and 3b is E. | I | = E / (n · μ ₀ · S · ω)} (Equation 3), and the induced voltage E of the coil 3 allows the current flowing through the bus bar 1 to be measured.

In FIG. 15, the horizontal axis represents the circumferential position θ of the current measuring device, and the vertical axis represents the induced voltage E _t per unit length in the circumferential direction of the current measuring device having only the other bus 11 in FIG. It shows the characteristics. When the winding density and the cross-sectional area of the interlinkage are constant, the sum of the plus side induced voltage + E _t and the minus side induced voltage −E _t becomes zero, and the measurement error of the current measuring device due to the current flowing through the other bus 11 is Does not occur.

[0008]

Since the conventional current measuring device is constructed as described above, the coil chains for winding the magnetic flux generated by the busbar 1 are wound at an equal winding density in the circumferential direction of the busbar. When the cross-sectional area is the same in the circumferential direction of the busbar 1,
The current flowing through the bus bar 1 can be accurately measured without being affected by the magnetic field generated by the current flowing through the other bus lines 11 other than the bus bar 1.

However, due to manufacturing error, the equal winding density and the equal cross-sectional area cannot be obtained. Manufacturing error occurs due to the following reasons. Since the winding is wound over a long distance, and the winding density is different between the inner diameter side and the outer diameter side, the winding density n in the circumferential direction is not uniform. Further, since the winding densities on the inner diameter side and the outer diameter side are different, in the case of a multi-layer winding coil, even if interlayer insulation is provided, the interlinking cross-sectional area changes due to the force when winding the upper layer winding. Further, the winding core 2 has an annular shape, and therefore, the cross-sectional shape is rectangular for ease of manufacturing. For this reason,
When winding the winding, it is difficult for the winding core 2 to come into close contact with the winding core 2, and the interlinking cross-sectional area S of the magnetic flux is not uniform.

For these reasons, the equal winding density and the equal magnetic flux linkage cross-sectional area, which are the conditions for deriving (Equation 2) to (Equation 3), are not obtained, and measurement errors are likely to occur. In addition, after the coil is manufactured, the induced voltage E is unlikely to reach the predetermined voltage. Therefore, the uppermost layer of the coil 3 is rewound, the number of turns at the predetermined voltage is wound at equal intervals, and it is possible to measure whether or not the voltage becomes the predetermined voltage. This is necessary, and thus, there is a problem that the manufacturing is difficult because the coil is rewound and rewound after the coil is manufactured in order to obtain a predetermined induced voltage, and it takes a long time to adjust the induced voltage.

There is also a problem that the core 2 becomes large as the current measuring device becomes large, and a large winding machine is required in order to wind the coil 3 using the large core 2.

Further, the induced voltage due to the current flowing through the other bus 11 is slightly deviated from the induced voltage E _t per unit length shown in FIG. 15 due to variations in the winding density and the flux linkage cross-sectional area.
The sum of the plus side induced voltage + E _t and the minus side induced voltage −E _t does not become zero, and a measurement error occurs.

The present invention has been made in order to solve the above problems, and it is possible to manufacture a winding density and an interlinkage cross-sectional area uniformly, and a current measuring device having a high measurement accuracy with no error, and a predetermined measuring device. It is an object to obtain a current measuring device that can easily obtain a voltage.

[0014]

A current measuring device according to a first aspect of the present invention is a current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar. A coil is composed of a plurality of split coils formed by winding a predetermined number of turns on the outer peripheral surface of a cylindrical winding core, and a central axis of the split coil is the axis of the busbar on a plane perpendicular to the axis of the busbar. It consists of a plurality of split coils connected in series at equal intervals centered on the axis of the busbar so that it is the same as the tangent to a circle centered on the center. is there.

A current measuring device according to a second aspect of the present invention is a current measuring device for measuring a current flowing through the bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar.
The coil has at least twelve or more split coils formed by winding a winding on the outer peripheral surface of a cylindrical winding core at a predetermined number of turns, on a plane perpendicular to the axis of the bus bar, and the center of the split coil. Arranged at equal intervals and centered on the axis of the busbar so that the axis is the same as the tangent to a circle centered on the axis of the busbar, and connecting a plurality of the split coils in series. It is configured by.

A current measuring device according to a third aspect of the present invention is a current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil is a circle. A plurality of split coils, each of which is formed by winding a predetermined number of turns on the outer peripheral surface of a columnar core, and whose voltage adjustment terminals are provided near the end of the winding. On top of this, the split coils are arranged at equal distances about the center line of the busbar and at equal intervals so that the center axis of the split coil is the same as the tangent line of the circle centered on the shaft center of the busbar, and a plurality of split coils are provided. It is configured by connecting coils in series.

A current measuring device according to a fourth aspect of the present invention is a current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil is On the plane perpendicular to the axis of the bus bar, the center axes are arranged at the same distance and equidistantly from the axis of the bus bar so that the center axis is the same as the tangent of a circle centered on the axis of the bus bar. And a magnetic shield having a plurality of split coils formed by winding a predetermined number of turns on the outer peripheral surface of a cylindrical core connected in series, and further configured so as not to form one turn. It is provided so as to surround.

Further, a current measuring device according to a fifth aspect of the present invention is a current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil is a bus bar. On the plane perpendicular to the axis of the bus, the center axis is arranged at the same distance from the axis of the bus bar at the same distance so that the center axis is the same as the tangent of a circle centered on the axis of the bus bar. , A plurality of split coils formed by winding a predetermined number of turns on the outer circumferential surface of the first cylindrical winding core, and a center axis on the plane on which the split coils are arranged with the center axis of the bus bar as the center. The outer circumference of a second cylindrical core having an outer diameter smaller than that of the first cylindrical core and equidistantly spaced about the axis of the busbar so as to be the same as the tangent to the circle. The same number of voltage adjustment coils as the number of split coils, in which the number of turns of the split coil is smaller than the number of turns of the split coil. It is those with a door.

Further, according to a sixth aspect of the present invention, in the current measuring instrument, the current flowing in the measured busbar by the induced voltage of the coil arranged on the outer circumference of the measured busbar in the plural busbars arranged in parallel with each other. Is a current measuring device, wherein the coil is on a plane perpendicular to the axis of the measured bus,
A first cylindrical winding core, which is arranged at equal intervals around the axis of the measured busbar so that the center axis is the same as the tangent of a circle centered on the axis of the measured busbar. A plurality of split coils formed by winding a predetermined number of turns on the outer peripheral surface of the coil, and a split coil positioned on a plane on which the split coils are arranged in a direction perpendicular to the plane on which the plurality of busbars are arranged. And a voltage adjusting coil formed by winding a winding on the outer peripheral surface of a second cylindrical core having an outer diameter smaller than that of the first cylindrical core, the number of windings being smaller than the number of turns of the split coil. Be prepared.

Further, a current measuring device according to a seventh aspect of the present invention is a current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil is a bus bar. On a plane perpendicular to the axis of the, so that the central axis is the same as the tangent of a circle centered on the axis of the busbar, are arranged at equal intervals around the axis of the busbar, In addition, a plurality of split coils each having a predetermined number of turns of a winding wound around the outer peripheral surface of a cylindrical core connected in series are provided, and at least one split coil includes a plurality of split coils. It is arranged so as to be movable in the axial direction of the busbar on the plane provided.

The current measuring device according to claim 8 of the present invention is a current measuring device for measuring a current flowing through the bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar.
The coil has a plurality of split coils formed by winding a winding on the outer peripheral surface of a cylindrical winding core at a predetermined number of turns, and a central axis of the split coil is arranged on a plane perpendicular to the axis of the busbar. To be the same as the tangent to the circle centered on the axis of the busbar,
Split coils having a difference voltage between the induced voltage of each split coil and the reference voltage that is larger than the average value and split coils that are smaller than the average value are alternately arranged at equal intervals around the axis of the bus bar. In addition, a plurality of split coils are connected in series.

According to a ninth aspect of the present invention, in the current measuring device, another bus bar is arranged in the vicinity of the measured bus bar, and the induced voltage of the coil arranged on the outer circumference of the measured bus bar causes A current measuring device for measuring a current flowing through a bus to be measured, wherein the coil comprises a plurality of split coils formed by winding a winding on a peripheral surface of a cylindrical core at a predetermined number of turns, and an axis of the bus bar. On a plane perpendicular to, so that the central axis of the split coil is the same as the tangent of a circle centered on the axis of the busbar, at equal intervals at the same distance centered on the axis of the busbar, Further, the divided coil in which the difference voltage between the induced voltage of each divided coil and the reference voltage is closest to the average value is arranged in the vicinity of the other bus bar, and a plurality of divided coils are connected in series. It is a thing.

A current measuring device according to a tenth aspect of the present invention is a current measuring device for measuring a current flowing through the busbar by an induced voltage of a coil arranged on the outer periphery of the busbar, wherein the coil is a columnar shape. A plurality of split coils each having a predetermined number of turns wound around the outer peripheral surface of the winding core are arranged on a plane perpendicular to the axis of the busbar, and the central axis of the split coil is the axis of the busbar. In order to be the same as the tangent line of the centered circle, at the same distance and at equal intervals around the axis of the bus bar,
In addition, the split coils having the same difference voltage between the induced voltage of each split coil and the reference voltage are arranged at opposing positions, and the plurality of split coils are connected in series.

[0024]

In the current measuring device according to the first aspect of the present invention, the coil has a plurality of split coils each having a predetermined number of turns wound around the outer peripheral surface of the cylindrical winding core, and the split coil is provided around the axis of the bus bar. On a plane perpendicular to the plane, the split coils are arranged at equal intervals at the same distance about the axis of the busbar so that the central axis of the split coil is the same as the tangent of a circle centered on the axis of the busbar, and Since it is configured by connecting a plurality of split coils in series, the number of turns of each split coil can be made constant, the winding densities of the coil on the side close to the bus bar and the winding density on the side far from the bus bar can be the same, and each split The winding density and interlinkage cross-sectional area of the coil can be made the same, the adjustment amount of the induced voltage induced in the coil can be reduced, and the measurement error can be reduced. Further, the split coil becomes small, and the split coil can be wound by a small winding machine.

Further, in the current measuring device according to the second aspect of the present invention, by forming at least twelve or more of the first-half split coils, the current measuring device is provided at a position concentric with the bus bar, and a predetermined distance from the bus bar. When another busbar is provided at a distant place, a high measurement accuracy with an extremely small error can be obtained by taking into account an equidistant mounting error from the busbar of the split coil, an even placement error in the circumferential direction of the busbar, and the like.

Further, in the current measuring device according to the third aspect of the present invention, since the voltage adjusting terminal is provided in the vicinity of the winding end of the winding of the split coil constituting the coil, the induction induced in the coil is induced. When the voltage is higher than the predetermined voltage, the voltage adjusting terminal is used for the series connection of the split coils, so that the induced voltage induced in the split coils can be reduced and the induced voltage in the coils can be adjusted to the predetermined voltage.

In the current measuring device according to the fourth aspect of the present invention, since the coil composed of the plurality of split coils is surrounded by the magnetic shield configured so as not to form one turn, the bus bar to be measured. The influence of the magnetic flux from the current flowing through the bus lines other than the above is reduced, and the measurement error can be reduced.

Further, in the current measuring device according to the fifth aspect of the present invention, a plurality of split coils each having a predetermined number of turns of the winding on the outer peripheral surface of the first cylindrical core, and an outer diameter of the split coil. First
A coil is composed of a split coil formed by winding a winding on the outer peripheral surface of a second columnar core smaller than the columnar core of No. 3 with a number of turns smaller than the number of turns of the split coil, and a voltage adjustment coil of the same number. Therefore, the induced voltage induced in the voltage adjustment coil is reduced, the minimum adjustment voltage can be significantly reduced, and the induced voltage of the coil can be adjusted to a predetermined voltage with high accuracy.

In the current measuring device according to the sixth aspect of the present invention, a plurality of split coils formed by winding a predetermined number of turns around the outer peripheral surface of the first cylindrical winding core and a plurality of busbars are provided. A second cylindrical core provided on a split coil positioned on a plane on which the split coil is arranged, and having an outer diameter smaller than that of the first cylindrical core, in a direction perpendicular to the plane on which the core is arranged. Since the coil is composed of the voltage adjusting coil formed by winding the winding on the outer peripheral surface with a smaller number of turns than the number of turns of the split coil, the split coil in the direction perpendicular to the plane on which the plurality of busbars are arranged is In the split coil and the voltage adjustment coil located on the plane where they are placed, the magnetic flux generated by the current flowing in the busbars other than the busbar to be measured will interlink almost at right angles, and the induced voltage is hardly induced. , Depending on the current flowing through the measured bus Only the voltage induced to reliably adjusted.

Further, in the current measuring device according to the seventh aspect of the present invention, at least one split coil of the plurality of split coils forming the coil is arranged on a plane on which the plurality of split coils are arranged. By disposing the split coil so as to be movable in the axial direction of the bus bar, the split coil is moved in the axial direction of the bus bar without increasing or decreasing the voltage adjusting means to increase or decrease the induced voltage induced in the split coil. Can be adjusted to a predetermined voltage.

Further, in the current measuring device according to the eighth aspect of the present invention, the divided coil in which the differential voltage between the induced voltage of each divided coil and the reference voltage is larger than the average value and the divided coil smaller than the average value are alternately arranged. By arranging them, variations in induced voltage due to variations in winding density and interlinkage cross-sectional area of each split coil are compensated by neighboring split coils, and measurement error is reduced.

Further, in the current measuring device according to the ninth aspect of the present invention, the induced current of the coil arranged on the outer periphery of the measured bus bar in which the other bus bar is arranged in the vicinity causes the current to flow to the measured bus line. When measuring the current, by disposing the split coil in which the differential voltage between the induced voltage of each split coil and the reference voltage is closest to the average value, the measurement error due to the other bus is caused in the other bus. Since the closest divided coil is the largest, the induced voltage due to the other bus is reduced to reduce the measurement error.

Further, in the current measuring device according to the tenth aspect of the present invention, the split coils having the same difference voltage between the induced voltage of each split coil and the reference voltage are arranged at the opposite positions, so that the opposite phases are obtained. The difference voltage between the split coil closest to the other bus bar and the split coil farthest from the other bus line is made equal to cancel the induced voltage due to the other bus line to reduce the measurement error.

[0034]

Embodiments of the present invention will be described below with reference to the drawings. Example 1. The first embodiment is an embodiment of the current measuring device according to the first to third aspects. FIG. 1 is a first embodiment of the present invention.
Is a front view of the current measuring device, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a front view showing a winding state of the current measuring device according to the first embodiment of the present invention.

In these figures, FIGS.
The same or corresponding parts as those of the conventional current measuring device shown in FIG. In FIG, 4 ₁
Numerals 4 to ₁₂ are split coils in which the winding 6 is wound around the outer peripheral surface of the cylindrical core 5 by a predetermined number of turns, and 7 is a split coil 4 _1.
~ 4 ₁₂ ring-shaped flat plate split coil fixing frame,
Reference numeral 8 is a fixture for attaching the split coils 4 ₁ to 4 ₁₂ to the split coil fixing frame 7.

Here, the split coil fixing frame 7 and the split coils 4 ₁ to 4 ₁₂ are provided concentrically with respect to the bus bar 1. Also, split coil 4 _{1-4 12} uniformly while being disposed with respect to the circumferential direction, the split coil ₄₁ to ₁₂ cylindrical
Are arranged so that the central axis of the is the same as the tangent of a circle whose axis is the generatrix 1. Further, the split coils 4 ₁ to 4 ₁₂ arranged in this way have windings 6 connected in series, and the coil terminals p and q are used as voltage measurement terminals. Further, lead wires 9 _{1 to} 9 ₁₂ as voltage adjustment terminals are provided near the winding ends of the windings 6 of the split coils 4 ₁ to 4 ₁₂ , respectively.

Next, the operation of the first embodiment will be described. Split coils 4 ₁ to 4 by current I flowing through bus 1
_A magnetic field H is generated in ₁₂ and an induced voltage E is induced between the coil terminals p and q. The induced voltage E is measured to measure the current I flowing through the bus 1.

In the current measuring device having such a configuration, although the winding 6 is not wound between the split coils 4 ₁ to 4 ₁₂ , the split coils 4 ₁ to 4 ₁₂ have the same number of turns. , And has an equal winding density in the circumferential direction of the busbar 1. Also,
Since the cylindrical core 5 has a cylindrical shape, the winding 6 can be wound in close contact with the cylindrical core 5, and since each cylindrical core 5 is cylindrical and has the same size, it is close to the busbar 1. The winding densities of the side and the far side can be equalized, and the cross-sectional areas of the magnetic fluxes generated by the busbars 1 are the same. Therefore, the measurement error can be reduced.

In FIG. 3, when a predetermined current is applied to the bus bar 1 and the induced voltage E between the coil terminals p and q is larger than the predetermined voltage, for example, one turn is less than the number of turns of the split coils 4 ₁ to 4 _12. The induced lines 9 _{1 to} 9 ₁₂ are connected to each other to reduce the induced voltage induced in the divided coils 4 ₁ to 4 ₁₂ and reduce the induced voltage E between the coil terminals p and q to reduce the induced voltage. Can be adjusted.

[0040] This connection re, when the induced voltage becomes less than the predetermined voltage, in order to reduce the change in the winding density, split coil ₄₁ to ₁₂ one every other lead lines, such as lead wire 9 ₁ , 9 ₃ , 9 ₅ , 9 ₇ , 9 ₉ ,
A split coil connecting or facing each other 9 ₁₁ , for example, a leader line 9 _{1 of the} split coils 4 ₁ and 4 _7.
When such as by connecting the 9 ₇ only it can be adjusted induced voltage.

Next, two-dimensional calculation was carried out in order to investigate the relationship between the number of divisions of the divided coil and the error. As shown in FIG. 4, the analysis shape is such that a current measuring device 10 having a center radius r ₀ composed of split coils 4 ₁ to 4 ₁₂ and split coil fixing frame 7 is provided concentrically with bus line 1 of infinite length. An infinitely long other bus bar 11 is provided at a position apart from D. The voltage e induced in one coil is calculated by the following equation. e = 2 · π · f · d · ∫2 · 10 ⁻⁷ · I / r · dL [integration range: L = a2 to a1] = 4 · π · 10 ⁻⁷ · d · I · f · {log ( a2) -log (a1)} (Equation 4)

Where π is the angular frequency, f is the power supply frequency,
d is the depth of the split coils 4 ₁ to 4 ₁₂ , r is the distance between the winding and the center of the busbar, a1 is the distance between the winding near the busbar and the busbar,
a2 is the distance between the other winding and the bus bar, and I is the current flowing through the bus bar.

Each split coil 4 forming a split coil
(Equation 4) is applied to ₁ to 4 ₁₂ and the respective voltages are added to obtain the induced voltage E of the current measuring device 10. An error η which is the ratio (percentage) of the voltage generated by the other bus 11 to the induced voltage generated by the bus 1 of the current measurement target,
FIG. 5 shows the relationship with the division number M of the split coil.

As can be seen from FIG. 5, the busbars 1, 11
The measurement error increases as the distance approaches. In general, since the current measuring devices 10 are installed at the same position on each bus bar, when the bus lines are closest to each other, the ratio k (= D / r ₀ ) of the inter-bus line distance D to the radius r ₀ of the current measuring device 10 is 2. It is when From the result of FIG. 5, the measurement error when k = 2 is almost zero when the number of divisions M is 12, and even when the distance D between the busbars is closer (k = 1.5), the measurement error is 0.4
It is a percentage. Generally, the error of the current measuring device 10 needs to be within 1%. In consideration of the equidistant mounting error from the bus bar to the split coil fixing frame 7 of the split coil, the equal placement error in the circumferential direction of the bus bar, etc. The number M requires 12 or more.

As described above, according to the first embodiment, since the winding wire 6 is wound around the outer peripheral surface of the columnar cylindrical core 5, the winding wire 6 is closely attached to the cylindrical core 5. The interlinking cross-sectional area can be made uniform. Even in the case of multi-layer winding, since the winding density is the same, the interlinking cross-sectional area does not change due to the winding force. Therefore, the adjustment of the induced voltage is small, and high measurement accuracy with few errors can be obtained.

Since the coil is composed of the split coils 4 ₁ to 4 ₁₂ , the winding 6 can be wound by a small winding machine, and the coil can be easily manufactured.

Further, since the lead wires 9 _{1 to} 9 ₁₂ are provided in the vicinity of the winding end of the winding 6 of the split coils 4 ₁ to 4 ₁₂ ,
By connecting the windings 6 of the split coils 4 ₁ to 4 ₁₂ to the lead wires 9 _{1 to} 9 ₁₂ when connecting the windings 6 in series, the induced voltage between the coil terminals p and q can be adjusted without changing the error. The induced voltage can be easily adjusted to a predetermined voltage. Furthermore, since the adjustment of the induced voltage can be performed at the same time as the error test, the adjustment time of the induced voltage and the error test time can be significantly reduced.

Although the core is used as the cylindrical core 5 in the first embodiment, the same effect can be obtained even with a cylindrical core.

Example 2. The second embodiment is an embodiment of the current measuring device according to the fourth aspect. In the second embodiment, as shown in FIG. 6, a magnetic shield composed of shields 12a and 12b formed of a good conductor is provided so as to surround the split coils 4 ₁ to 4 ₁₂ . The split coil fixing frame installed equidistant to the bus bar 1 also serves as the shield 12a, and the shield 12b is attached to the shield 12a in a cantilever manner so that the magnetic shield does not form one turn. The other structure is the same as that of the first embodiment.

According to the second embodiment, the split coils 4 ₁ to
4 ₁₂ shields 12a, 12 disposed so as to surround the
The electromagnetic shield consisting of b is the bus bar 1 for current measurement.
Prevents the influence of magnetic flux from the electric current flowing through bus lines other than
The measurement error can be reduced and the measurement accuracy can be improved.

Example 3. The third embodiment is another embodiment of the current measuring device according to the fourth aspect. In the second embodiment,
The shield 12b constituting the magnetic shield is replaced by the shield 12
Although it is assumed that the shield 12b is attached to a by a cantilever, in the third embodiment, the shield 12b is attached to the shield 12a via an insulator so that the magnetic shield does not form one turn. Produce the effect of.

Example 4. The fourth embodiment is an embodiment of the current measuring device according to the fifth aspect. Embodiment 4 FIG. 7 is a front view of a current measuring device showing Embodiment 4 of the present invention.
3 _{1 to} 13 ₁₂ are voltage adjusting coils.

In the fourth embodiment, the split coils 4 ₁ to 4 _{12 are used.}
The cylindrical winding heart 5 (first cylindrical winding core) small diameter of the cylindrical winding core than (second cylindrical winding core), split coil 4 ₁
The number of turns of winding is less than that of 4 ₁₂ to form the voltage adjusting coils 13 _{1 to} 13 ₁₂ , and the split coil 4 is arranged so that its central axis is the same as the tangent to the circle with the bus 1 as the axis. ₁
To 4 ₁₂ are arranged at the side ends of the divided coils 4 ₁ to 4 respectively.
₁₂ and the voltage adjusting coils 13 _{1 to} 13 ₁₂ are arranged at the same distance and at equal intervals centered on the axis of the busbar 1. Further, the split coils 4 ₁ to 4 ₁₂ and the voltage adjusting coils 13 _{1 to} 13 ₁₂ are connected in series to form a current measuring device.

Here, the lead wires 9 _{1 to} 9 ₁₂ provided in the divided coils 4 ₁ to 4 ₁₂ as the voltage adjusting terminals in the first embodiment are the voltage adjusting coils 13 _{1 to} 13 _12.
It is provided in. The other configurations are the same as those in the first embodiment.

In the fourth embodiment, when the voltage of the induced voltage induced in the coil is adjusted, the voltage adjusting coils 13 _{1 to} 13 _{12 having} a smaller induced voltage than the divided coils 4 ₁ to 4 ₁₂ are.
Change the connection to the lead lines 9 _{1 to} 9 ₁₂ provided in
The induced voltage induced in each of the voltage adjusting coils 13 _{1 to} 13 ₁₂ is reduced to reduce the induced voltage E between the coil terminals p and q.

According to the fourth embodiment, the lead lines 9 ₁ to
9 ₁₂ provided with a voltage adjusting coil 1 with a small induced voltage
Since 3 _{1 to} 13 ₁₂ and the branch coils 4 ₁ to 4 ₁₂ are connected in series, the lowest adjustment voltage of the induced voltage induced in the coil is one turn of the split coil, compared to the first embodiment. The minimum adjustment voltage can be significantly reduced, and the induced voltage can be adjusted with high accuracy.

Example 5. The fifth embodiment is another embodiment of the current measuring device according to the fifth aspect. In the fourth embodiment,
Voltage adjusting coils 13 _{1 to} 13 ₁₂ and branch coils 4 ₁ to 4 ₁₂ provided with lead lines 9 _{1 to} 9 _{12 and} having a small induced voltage.
And are connected in series to form a current measuring device, and the lead wire 9 ₁
To 9 ₁₂ to make the connection re, although it is assumed that adjusts the voltage induced in the coil, in this embodiment 5, the branch coils 41 _{to 12} connected in series, the lead lines 9 ₁
9 ₁₂ provided with a voltage adjusting coil 1 with a small induced voltage
An electric current measuring device is composed of 3 _{1 to} 13 _12, and the voltage adjustment coils 13 _{1 to} 13 ₁₂ are connected to each other, and the lead lines 9 _{1 to} 9 ₁₂ are connected to each other to induce an induced voltage in the coil. The same effect as in the fourth embodiment can be obtained by adjusting

[0058] Incidentally, the Example 4 and 5, the split coil ₄₁ to ₁₂ voltage adjustment coil _{131-134 12} side end portion of the
Is provided, but the voltage adjustment coil 13 ₁
The positions of ˜13 ₁₂ are not limited to the side ends of the split coils 4 ₁ to 4 ₁₂ and may be arranged so that their central axes are the same as the tangents of a circle with the bus 1 as an axis. The cylindrical core 5 of each of the split coils 4 ₁ to 4 ₁₂ may be replaced with a cylindrical core, and the coil 5 may be arranged therein. Further, as shown in Examples 2 and 3, a magnetic shield may be arranged so as to surround the split coils 4 ₁ to 4 ₁₂ and the voltage adjusting coils 13 _{1 to} 13 ₁₂ .

Example 6. The sixth embodiment is an embodiment of the current measuring device according to the sixth aspect. In the fourth embodiment, the voltage adjusting coil 13 ₁ is provided in each of the split coils 4 ₁ to 4 _12.
It is assumed that disposed to 13 _12, but in the sixth embodiment, the opposed pair of divided coils, for example, split coil 4
Voltage adjusting coils 13 ₄ and 13 ₁₀ are provided only on ₄ and 4 ₁₀ .

Here, the split coils 4 ₄ and 4 ₁₀ are shielded when a plurality of busbars are arranged along the X axis in FIG. 7, that is, when a plurality of busbars are arranged parallel to one plane. It is a split coil located at a position of a busbar 1 which is a measurement busbar, in a direction perpendicular to the plane.

In the sixth embodiment, since the voltage adjusting coils 13 ₄ and 13 ₁₀ are partially provided, the winding density does not become equal, but the magnetic flux generated by the current flowing through the other bus bar causes the voltage adjusting coil 13 _Since they interlink at right angles to ₄ and 13 ₁₀ , an induced voltage due to a current flowing through another bus hardly occurs. Therefore, only the induced voltage induced by the current flowing through the bus 1 which is the bus to be measured can be adjusted by the voltage adjusting coils 13 ₄ and 13 ₁₀ .

As described above, according to the sixth embodiment, the number of installed voltage adjusting coils can be greatly reduced, and the induced voltage can be adjusted without changing the error.

Example 7. The seventh embodiment is another embodiment of the current measuring device according to the sixth aspect. In the sixth embodiment,
When multiple busbars are arranged parallel to one plane,
The voltage adjusting coil is arranged in a pair of split coils positioned at a measured busbar position in a direction perpendicular to the plane, but in this Embodiment 7, in FIG. The voltage adjustment coil 13 ₄ is arranged on one of the split coils positioned in the direction, for example, the split coil 4 ₄ .

According to the seventh embodiment, as compared with the sixth embodiment in which the voltage adjusting coil is arranged in the pair of split coils, an adjustment width of about 1/2 can be obtained, and the induced voltage can be adjusted. In addition, the number of voltage adjustment coils installed can be reduced.

Example 8. The eighth embodiment is an embodiment of the current measuring device according to the seventh aspect. 8 is a plan view of a current measuring device showing an eighth embodiment of the present invention, and FIG. 9 is a sectional view taken along the line IX-IX in FIG. 8, in which 14 is a split coil mounting plate and 15 is a split coil. The slits are provided in the fixed frame 7 in the axial direction of the busbar 1, that is, in the radial direction. In the seventh embodiment, slits 15 are provided at the positions of the split coil fixed frames 7 to which the split coils 4 ₄ and 4 ₁₀ are attached. It is provided. 16 is a scale.

In the eighth embodiment, the split coils 4 ₄ , 4 _{10 are used.}
Is attached to the split coil mounting plate 14, and the split coil mounting plate 14 is slidably attached to the slit 15.
Here, the split coils 4 ₄ and 4 ₁₀ are measured busbars when a plurality of busbars are arranged along the X axis in FIG. 7, that is, when a plurality of busbars are arranged in parallel in one plane. The split coil is located at a position of a certain busbar 1 in a direction perpendicular to the plane.

In the eighth embodiment, when the induced voltage induced by the current flowing through the bus 1 to be measured deviates from the predetermined voltage, the split coils 4 ₄ and 4 ₁₀ are slit 15
Along the radial direction to increase / decrease the distance between the split coils 4 ₄ and 4 ₁₀ and the busbar 1 and to increase / decrease the induced voltage induced in the split coils 4 ₄ and 4 ₁₀ to increase the induced voltage of the coil. Can be adjusted, and a voltage adjusting coil or the like can be eliminated.

The scale 16 also divides the coils 4 ₄ ,
4 The adjustment position of ₁₀ can be grasped.

Further, since the magnetic flux generated by the current flowing through the other bus bar crosses the split coils 4 ₄ , 4 _{10 at} right angles, the induced voltage due to the current flowing through the other bus line is applied to the split coils 4 ₄ , 4 _10. It rarely happens. Therefore, it is possible to reliably adjust only the induced voltage induced by the current flowing through the bus 1 without changing the error.

In the eighth embodiment, when a plurality of busbars are arranged in parallel in one plane, a pair of divisions are formed at the position of the busbar 1 which is the busbar to be measured and in a direction perpendicular to the plane. Although the coils 4 ₄ , 4 ₁₀ are arranged slidably in the radial direction, only one of the split coils 4 ₄ , 4 ₁₀ may be slidable in the radial direction. Further, if only the busbar 1 needs to be considered, the induced voltage can be adjusted by disposing at least one of the plurality of split coils 4 ₁ to 4 ₁₂ slidably in the radial direction.

Example 9. This embodiment is an embodiment of the current measuring device according to claim 8. 10 relates to a ninth embodiment of the present invention, and in order to determine the arrangement of the divided coils 4 ₁ to 4 ₁₂ shown in FIG. 3, the difference voltage between the divided coils 4 ₁ to 4 _{12 and} the reference coil is measured. It is a block diagram. In the figure, 1
Reference numeral 7 is a reference coil, 18 is a magnetic flux generating coil, and the split coil 4 (each split coil 4 ₁ to 4 ₁₂ ) and the reference coil 17 are provided in the magnetic flux generating coil 18 where the same magnetic flux is generated. Power is supplied to the magnetic flux generating coil 18.

Then, the differential voltage E _d of the induced voltage generated between the divided coils 4 (each divided coil 4 ₁ to 4 ₁₂ ) and the reference coil 17 is measured, and each divided coil 4 ₁ to 4 ₁₂ and the reference coil are measured. Split coils larger than the average voltage E _a given by the arithmetic mean value of the difference voltage E _d with respect to 17 and small split coils are alternately arranged in FIG.

[0073] Figure 11 is the measurement result and the divided coil _{4 1}
Shows the ~ 4 ₁₂ arrangement of split coils provided opposite shall close differential voltage E _d. Any of the divided coils 4 ₁ to 4 ₁₂ may be used as the reference coil 17. In addition, without using the magnetic flux generating coil 18, the induced voltage generated by passing a current through the bus bar 1 in FIG. 1 is measured, and the differential voltage E _d is calculated based on the measured induced voltage, which is larger than the average voltage E _a. And small split coils may be arranged alternately.

According to the ninth embodiment described above, although there is a portion where no winding is wound between the split coils, the split coil 4
_{Since 1} to 4 ₁₂ have the same number of turns, the winding densities are equal in the circumferential direction of the busbar. In addition, the variation of the induced voltage of each shunt coil due to the variation of the winding density and the interlinkage cross-sectional area of each shunt coil is combined with a split coil having a large difference voltage between the reference coil 17 and a small split coil to divide the neighboring coils. It is possible to reduce the measurement error by compensating between the coils.

Example 10. The tenth embodiment is defined in claim 9.
The present invention relates to another embodiment of the current measuring device according to the ninth embodiment. In the tenth embodiment, as shown in FIG.
It is assumed that there is another busbar 11 in the vicinity of the busbar 1, and the induced voltage by the other busbar 11 is the largest in the split coil which is the largest in the other busbar 11. Therefore, the other busbar 11 is in the vicinity of the busbar 1 in this way. In this case, the divided coil whose difference voltage from the reference coil 17 is closest to the average voltage E _a is the other bus bar 11.
The measurement error can be reduced by providing it at a position close to.

Example 11. This eleventh embodiment is defined by claim 1.
0 is another embodiment of the current measuring device according to the ninth embodiment. Also in this embodiment, another busbar 1 is provided near the busbar 1.
Suppose there is one. The voltage induced by the other bus 11 is greater in the split coil closest to the other bus 11, but the other bus 1
The split coil farthest from 1 has the opposite phase of the induced voltage generated by the split coil closest to the other bus 11, and the split coil generating the opposite phase generates the largest voltage. Therefore, by providing a split coil closest to the other bus bar 11 and a split coil farthest from the other bus bar 11 with the same difference voltage, the induced voltage due to the other bus bar 11 is canceled and the measurement error can be reduced. .

[0077]

Since the present invention is constituted as described above, it has the following effects.

The current measuring device according to claim 1 of the present invention is
A current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer circumference of the bus bar, wherein the coil comprises a plurality of windings wound around an outer peripheral surface of a cylindrical core at a predetermined number of turns. Put the split coils on a plane perpendicular to the axis of the busbar so that the center axis of the split coil is the same as the tangent of a circle centered on the axis of the busbar. Since the coils are arranged at the same distance at equal intervals and a plurality of split coils are connected in series, the number of turns of each split coil can be made constant, and the coil turns on the side close to the busbar and the coil on the side far from the busbar. The linear density can be made the same, and the winding density and interlinking cross-sectional area of each divided coil can be made the same, the adjustment amount of the induced voltage induced in the coil can be reduced, and the measurement error can be reduced.
Furthermore, a small winding machine can be used, and the coil can be easily manufactured.

Further, a current measuring device according to a second aspect of the present invention is a current measuring device for measuring a current flowing through the bus by an induced voltage of a coil arranged on the outer periphery of the bus.
The coil has at least twelve or more split coils formed by winding a winding on the outer peripheral surface of a cylindrical winding core at a predetermined number of turns, on a plane perpendicular to the axis of the bus bar, and the center of the split coil. Arranged at equal intervals and centered on the axis of the busbar so that the axis is the same as the tangent to a circle centered on the axis of the busbar, and connecting a plurality of the split coils in series. Therefore, when the current measuring device is installed concentrically with the busbar, and another busbar is provided at a position distant from the busbar by a certain distance, equidistant mounting error from the busbar of the split coil, busbar High measurement accuracy with very few errors can be obtained in consideration of circumferentially even placement error.

Further, a current measuring device according to a third aspect of the present invention is a current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil is a circle. A plurality of split coils, each of which is formed by winding a predetermined number of turns on the outer peripheral surface of a columnar core, and whose voltage adjustment terminals are provided near the end of the winding. On top of this, the split coils are arranged at equal distances about the center line of the busbar and at equal intervals so that the center axis of the split coil is the same as the tangent line of the circle centered on the shaft center of the busbar, and a plurality of split coils are provided. Since the coils are connected in series, it is possible to adjust the induced voltage of the coil to a predetermined voltage by using the voltage adjusting terminal for connecting the split coils in series.

A current measuring device according to a fourth aspect of the present invention is a current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil comprises: On the plane perpendicular to the axis of the bus bar, the center axes are arranged at the same distance and equidistantly from the axis of the bus bar so that the center axis is the same as the tangent of a circle centered on the axis of the bus bar. And a magnetic shield having a plurality of split coils formed by winding a predetermined number of turns on the outer peripheral surface of a cylindrical core connected in series, and further configured so as not to form one turn. Since it is provided so as to surround, the influence of the magnetic flux from the current flowing through the bus bar other than the bus bar to be measured is reduced, and the measurement error can be reduced.

A current measuring device according to a fifth aspect of the present invention is a current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil is a bus bar. On the plane perpendicular to the axis of the bus, the center axis is arranged at the same distance from the axis of the bus bar at the same distance so that the center axis is the same as the tangent of a circle centered on the axis of the bus bar. , A plurality of split coils formed by winding a predetermined number of turns on the outer circumferential surface of the first cylindrical winding core, and a center axis on the plane on which the split coils are arranged with the center axis of the bus bar as the center. The outer circumference of a second cylindrical core having an outer diameter smaller than that of the first cylindrical core and equidistantly spaced about the axis of the busbar so as to be the same as the tangent to the circle. The same number of voltage adjustment coils as the number of split coils, in which the number of turns of the split coil is smaller than the number of turns of the split coil. Is provided with the bets, small voltage induced on the voltage adjustment coil, the lowest adjustment voltage can be greatly reduced, thereby adjusting the induced voltage of the coil with high accuracy to a predetermined voltage.

According to a sixth aspect of the present invention, in the current measuring device, the current flowing in the measured busbar by the induced voltage of the coil arranged on the outer periphery of the measured busbar in the plurality of busbars arranged in parallel with each other. In the current measuring device, the coil is on a plane perpendicular to the axis of the measured bus,
A first cylindrical winding core, which is arranged at equal intervals around the axis of the measured busbar so that the center axis is the same as the tangent of a circle centered on the axis of the measured busbar. A plurality of split coils formed by winding a predetermined number of turns on the outer peripheral surface of the coil, and a split coil positioned on a plane on which the split coils are arranged in a direction perpendicular to the plane on which the plurality of busbars are arranged. And a voltage adjusting coil formed by winding a winding on the outer peripheral surface of a second cylindrical core having an outer diameter smaller than that of the first cylindrical core, the number of windings being smaller than the number of turns of the split coil. Since the voltage adjustment coil is provided, almost no induced voltage is induced in the voltage adjusting coil by the current flowing in the buses other than the measured bus, and only the induced voltage induced by the current flowing in the measured bus can be reliably adjusted.

Further, a current measuring device according to a seventh aspect of the present invention is a current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil is a bus bar. On a plane perpendicular to the axis of the, so that the central axis is the same as the tangent of a circle centered on the axis of the busbar, are arranged at equal intervals around the axis of the busbar, In addition, a plurality of split coils each having a predetermined number of turns of a winding wound around the outer peripheral surface of a cylindrical core connected in series are provided, and at least one split coil includes a plurality of split coils. Since it is arranged so as to be movable in the axial direction of the bus bar on the provided plane, it is possible to easily adjust the induced voltage of the coil without the need for adjusting means such as a voltage adjusting coil.

The current measuring device according to claim 8 of the present invention is the current measuring device for measuring the current flowing through the busbar by the induced voltage of the coil arranged on the outer periphery of the busbar.
The coil has a plurality of split coils formed by winding a winding on the outer peripheral surface of a cylindrical winding core at a predetermined number of turns, and a central axis of the split coil is arranged on a plane perpendicular to the axis of the busbar. To be the same as the tangent to the circle centered on the axis of the busbar,
Split coils having a difference voltage between the induced voltage of each split coil and the reference voltage that is larger than the average value and split coils that are smaller than the average value are alternately arranged at equal intervals around the axis of the bus bar. In addition, since a plurality of split coils are connected in series, variations in induced voltage due to variations in winding density and interlinking cross-sectional area of each split coil are compensated by neighboring split coils, and measurement error is compensated. Can be reduced.

According to a ninth aspect of the present invention, in the current measuring instrument, the current flowing through the measured busbar by the induced voltage of the coil arranged on the outer periphery of the measured busbar where the other busbar is arranged in the vicinity. In the current measuring device for measuring, the coil comprises a plurality of split coils formed by winding a winding on the outer peripheral surface of a cylindrical winding core at a predetermined number of turns on a plane perpendicular to the axis of the bus bar. , So that the center axis of the split coil is the same as the tangent to a circle centered on the axis of the busbar, at the same distance about the axis of the busbar at equal intervals, and the induced voltage of each split coil And a divided coil whose difference voltage between the reference voltage and the reference value is closest to the average value is arranged near the other busbar,
Since a plurality of split coils are connected in series, the measurement error due to the other bus is the largest for the split coil closest to the other bus, so the induced voltage due to the other bus should be reduced to reduce the measurement error. You can

Further, the current measuring device according to a tenth aspect of the present invention is a current measuring device for measuring a current flowing through the bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil is a columnar shape. A plurality of split coils each having a predetermined number of turns wound around the outer peripheral surface of the winding core are arranged on a plane perpendicular to the axis of the busbar, and the central axis of the split coil is the axis of the busbar. In order to be the same as the tangent line of the centered circle, at the same distance and at equal intervals around the axis of the bus bar,
And, since the divided coils in which the differential voltage between the induced voltage of each divided coil and the reference voltage is equal are arranged at the opposing positions, and the plurality of divided coils are connected in series,
The difference voltage between the split coil closest to the other bus and the split coil farthest from the other bus, which have opposite phases, can be made approximately the same, and the induced voltage due to the other bus can be canceled to reduce the measurement error.

[Brief description of drawings]

FIG. 1 is a front view of a current measuring device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a front view of the winding state of the current measuring device according to the first embodiment of the present invention.

FIG. 4 is an arrangement diagram for calculating the relationship between the number of divisions of the division coil and the error of the current measuring device of the present invention.

FIG. 5 is a graph showing the relationship between the number of divisions of the division coil of the current measuring device of the present invention and the error.

FIG. 6 is a cross-sectional view of essential parts of a current measuring device showing a third embodiment of the present invention.

FIG. 7 is a front view of a current measuring device according to a fourth embodiment of the present invention.

FIG. 8 is a front view of a current measuring device showing an eighth embodiment of the present invention.

9 is a sectional view taken along the line IX-IX in FIG.

FIG. 10 is a configuration diagram of a split coil induced voltage measuring device for explaining a ninth embodiment of the present invention.

FIG. 11 is a differential voltage characteristic diagram of the split coils measured according to FIG.

FIG. 12 is a front view showing an example of a conventional current measuring device.

13 is a sectional view taken along line XIII-XIII in FIG.

FIG. 14 is a front view showing a winding state of a conventional current measuring device.

FIG. 15 is a characteristic diagram of induced voltage per unit length by another bus of a conventional current measuring device.

[Explanation of symbols]

1 Bus bar 4 ₁ to 4 ₁₂ Split coil 5 Cylindrical winding core 6 Winding 9 _{1 to} 9 ₁₂ Leader wire (voltage adjustment terminal) 11 Other bus bar 12a, 12b Shield (magnetic shield) 13 _{1 to} 13 ₁₂ Voltage adjustment coil

Claims (10)

[Claims] 1. A current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer circumference of the bus bar, wherein the coil has a predetermined number of windings wound around an outer peripheral surface of a cylindrical winding core. A plurality of split coils formed by turning, on a plane perpendicular to the axis of the busbar, so that the center axis of the split coil is the same as the tangent of a circle centered on the axis of the busbar, An electric current measuring instrument, characterized in that it is arranged at equal intervals about the axis of the bus bar at equal intervals and a plurality of the divided coils are connected in series. 2. A current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer circumference of the bus bar, wherein the coil has a predetermined number of windings wound around an outer peripheral surface of a cylindrical winding core. At least twelve or more split coils formed by turning are placed on a plane perpendicular to the axis of the busbar so that the central axis of the split coil is the same as the tangent of a circle centered on the axis of the busbar. The current measuring device is characterized in that it is arranged at equal intervals around the axis of the bus bar at equal intervals, and a plurality of the divided coils are connected in series. 3. A current measuring device for measuring a current flowing through the bus bar by an induced voltage of a coil arranged on the outer circumference of the bus bar, wherein the coil has a predetermined number of windings on the outer peripheral surface of a cylindrical winding core. The plurality of split coils each having a voltage adjusting terminal provided near the winding end of the winding are arranged on a plane perpendicular to the axis of the busbar, and the central axis of the split coil is the busbar. So as to be the same as the tangent line of the circle centering on the axis of the center of the bus bar, and arranged at equal intervals about the axis of the bus bar, and connecting a plurality of the split coils in series. A current measuring device characterized in that 4. A current measuring device for measuring a current flowing through the bus bar by an induced voltage of a coil arranged on the outer periphery of the bus bar, wherein the coil is centered on a plane perpendicular to the axis of the bus bar. The axis is the same as the tangent line of the circle centered on the axis of the bus bar, and arranged at the same distance at the same distance centered on the axis of the bus bar, and connected in series,
A plurality of split coils each having a predetermined number of turns are wound around the outer peripheral surface of the cylindrical winding core, and a magnetic shield configured so as not to form one turn is provided surrounding the coil. A current measuring device characterized in that 5. A current measuring device for measuring a current flowing through the busbar by an induced voltage of a coil arranged on the outer circumference of the busbar, wherein the coil has a center on a plane perpendicular to an axis of the busbar. The outer peripheral surface of the first cylindrical winding core, which is arranged at equal intervals at the same distance around the axis of the bus bar so that the axis is the same as the tangent line of the circle around the axis of the bus bar. A plurality of split coils each having a predetermined number of turns of winding, and a center axis of which is the same as a tangent to a circle centered on the axis of the bus bar on a plane on which the split coils are arranged. A second core having an outer diameter smaller than that of the first columnar core and arranged at equal intervals around the axis of the bus bar.
5. A current measuring instrument, comprising: the number of turns of the windings wound around the outer peripheral surface of the cylindrical winding core, which is smaller than the number of turns of the split coil, and the same number of voltage adjusting coils as the split coil. 6. A current measuring device for measuring a current flowing through a measured bus by an induced voltage of a coil arranged on the outer circumference of the measured bus in a plurality of buses arranged in parallel to each other, wherein the coil is: On a plane perpendicular to the axis of the measured busbar, so that the central axis is the same as the tangent of a circle centered on the axis of the measured busbar, centered on the axis of the measured busbar. First, evenly spaced equidistantly
A plurality of split coils formed by winding a predetermined number of turns on the outer peripheral surface of the cylindrical winding core, and the split coils arranged at right angles to the plane on which the plurality of busbars are arranged. A winding is wound on the outer peripheral surface of a second cylindrical core having an outer diameter smaller than that of the first cylindrical core provided on the split coil on a plane with a smaller number of turns than that of the split coil. A current measuring device, comprising: a voltage adjusting coil that is rotated. 7. A current measuring device for measuring a current flowing through the busbar by an induced voltage of a coil arranged on the outer periphery of the busbar, wherein the coil has a center on a plane perpendicular to an axis of the busbar. The axis is the same as the tangent line of the circle centered on the axis of the bus bar, and arranged at the same distance at the same distance centered on the axis of the bus bar, and connected in series,
A plurality of split coils formed by winding a predetermined number of turns on the outer peripheral surface of the cylindrical winding core are provided, and at least one split coil is provided on a plane on which the plurality of split coils are arranged. A current measuring device, which is arranged so as to be movable in the axial direction of the bus bar. 8. A current measuring instrument for measuring a current flowing through the bus bar by an induced voltage of a coil arranged on the outer circumference of the bus bar, wherein the coil has a predetermined number of windings wound around an outer peripheral surface of a cylindrical winding core. A plurality of split coils formed by turning, on a plane perpendicular to the axis of the busbar, so that the center axis of the split coil is the same as the tangent of a circle centered on the axis of the busbar, Split coils having a difference voltage between the induced voltage of each split coil and the reference voltage that is larger than the average value and split coils that are smaller than the average value are alternately arranged at equal intervals around the axis of the bus bar. In addition, the current measuring device is configured by connecting a plurality of the divided coils in series. 9. A current measuring instrument, wherein another bus is arranged in the vicinity of the bus to be measured, and a current flowing through the bus to be measured is measured by an induced voltage of a coil arranged on the outer periphery of the bus to be measured. The coil is a plurality of split coils formed by winding a predetermined number of turns on the outer peripheral surface of a cylindrical core.
On the plane perpendicular to the axis of the bus bar, the central axis of the split coil is the same as the tangent of a circle centered on the axis of the bus bar, the same distance about the axis of the bus bar At equal intervals, a divided coil whose difference voltage between the induced voltage of each divided coil and the reference voltage is closest to the average value is arranged near the other busbar, and a plurality of divided coils are connected in series. A current measuring device characterized by being configured as follows. 10. A current measuring device for measuring a current flowing through a bus bar by an induced voltage of a coil arranged on the outer circumference of the bus bar, wherein the coil has a predetermined number of windings wound around an outer peripheral surface of a cylindrical winding core. A plurality of split coils formed by turning, on a plane perpendicular to the axis of the busbar, so that the center axis of the split coil is the same as the tangent of a circle centered on the axis of the busbar, A plurality of split coils are arranged at equal distances about the axis of the bus bar at equal intervals, and split coils having the same difference voltage between the induced voltage of each split coil and the reference voltage are arranged at opposite positions. An electric current measuring device characterized by being connected in series.