Current measuring device

Abstract

The utility model relates to a current measuring device. The current measuring device includes: a coil defining an outer space and an inner space in a three-dimensional space; the coil is provided with a notch communicating the external space and the internal space; the moving part is movably connected with the coil and is made of a magnetic material; the current measuring circuit is electrically connected with the coil; the moving part is connected with the coil to form a continuous structure, so that the magnetic field change generated by the measured conductor is converted into corresponding induced electromotive force; the current measuring circuit receives the induced electromotive force sensed by the coil and converts the induced electromotive force into a current value of the measured conductor. According to the current measuring device, the moving part is connected with the coil with the notch to form a continuous structure so as to measure the current of the measured conductor, control over current measurement of the measured conductor through the moving part is achieved, and loss of the coil in the current measuring process is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of current measurement, in particular to a current measuring device. Background Art

[0002] Rogowski coil is a widely used device for current measurement. It is a hollow ring-shaped coil that can be directly put on the conductor to be measured. When the AC current flowing through the conductor generates a magnetic field, the Rogowski coil will induce an AC voltage signal proportional to the current transformation ratio in the coil. After being processed by the integrator, this signal can accurately reproduce the waveform of the measured current signal, thereby realizing the detection of the current size.

[0003] At present, in order to put the Rogowski coil on the conductor to be measured, the complete Rogowski coil is generally made into two semicircular coils. The conductor to be measured can be placed by opening the two semicircular coils. The two semicircular coils need to be connected by a connecting wire.

[0004] However, since the two semicircular coils often need to be opened and closed, the connecting wires between the two semicircular coils are easily damaged, which in turn causes the coils to be easily damaged. Utility Model Content

[0005] The current measuring device provided in the embodiment of the present application can solve the defect that the existing coil is easily damaged.

[0006] The embodiment of the present application provides a current measuring device. The current measuring device includes: a coil defining an external space and an internal space in a three-dimensional space; the coil has a gap connecting the external space and the internal space; a moving part movably connected to the coil, the material of the moving part is a magnetic material; a current measuring circuit electrically connected to the coil; wherein the moving part is separated from the coil so that the measured conductor enters or leaves the internal space through the gap of the coil; the moving part is connected to the coil to form a continuous structure so that the magnetic field change generated by the measured conductor is converted into a corresponding induced electromotive force; the current measuring circuit receives the induced electromotive force sensed by the coil and converts it into the current value of the measured conductor.

[0007] Optionally, the moving part comprises a magnetic core.

[0008] Optionally, when the moving component is connected to the coil to form a continuous structure, part of the magnetic field generated by the measured conductor is transferred to the coil through the moving component, so that the coil senses the entire magnetic field generated by the measured conductor.

[0009] Optionally, the current measuring device further comprises a supporting component, and the coil is wound from one end of the supporting component to the other end of the supporting component to form a gap connecting the external space and the internal space.

[0010] Optionally, the supporting component includes: a component with a notch formed by cutting an annular component; or a component with a notch formed by cutting a hollow component of other shapes, or a component with a notch formed by at least one supporting component.

[0011] Optionally, the coil is folded in half to form a fold and an output end; the fold is away from the output end to form a gap between the external space and the internal space; the output end is electrically connected to the current measurement circuit so that the current measurement circuit receives the induced electromotive force sensed by the coil.

[0012] Optionally, the coil is folded in half to form a first coil section and a second coil section; wherein the first coil section is wound from one end of the support component to the other end of the support component; the second coil section is laid on the surface of the support component and is laid from one end of the support component to the other end of the support component; the first coil section and the second coil section form two output ends at the other end of the support component, and the two output ends are electrically connected to the current measurement circuit so that the current measurement circuit receives the induced electromotive force sensed by the coil.

[0013] Optionally, the current measurement circuit includes: an integration circuit and a current conversion circuit; the coil is electrically connected to the integration circuit, and the integration circuit is electrically connected to the current conversion circuit; the integration circuit is used to integrate the induced electromotive force sensed by the coil to obtain an output voltage proportional to the current in the measured conductor; the current conversion circuit is used to convert the output voltage into the current value of the measured conductor.

[0014] Optionally, the magnetic permeability of the moving component is greater than a preset value.

[0015] At least one advantageous aspect of the current measuring device provided in the embodiment of the present application is: a coil defining an external space and an internal space in a three-dimensional space; the coil having a gap connecting the external space and the internal space; a moving part movably connected to the coil, the material of the moving part being a magnetic material; a current measurement circuit electrically connected to the coil; wherein the moving part and the coil are separated from each other so that the measured conductor enters or leaves the internal space through the gap of the coil; the moving part is connected to the coil to form a continuous structure so that the magnetic field changes generated by the measured conductor are converted into corresponding induced electromotive forces; the current measurement circuit receives the induced electromotive force sensed by the coil and converts it into a current value of the measured conductor, and by connecting the moving part to the coil with a gap to form a continuous structure to measure the current of the measured conductor, the current measurement of the measured conductor can be controlled by the moving part, and the loss of the coil during the current measurement process is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0017] Figure 1 is a schematic diagram of a typical Rogowski coil current sensor;

[0018] Figure 2 is another schematic diagram of a typical Rogowski coil current sensor;

[0019] Figure 3 Schematic diagram for measuring current for a typical two-coil combination;

[0020] Figure 4 A schematic diagram of a current measuring device provided in an embodiment of the present application;

[0021] Figure 5 A schematic diagram of a current measuring device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to facilitate the understanding of the utility model, the utility model is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on another element, or there can be one or more centered elements therebetween. When an element is described as "connected" to another element, it can be directly connected to another element, or there can be one or more centered elements therebetween. The orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "bottom" and the like used in this specification is based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0023] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by technicians in the technical field of the present invention. The terms used in this specification are only for the purpose of describing specific embodiments and are not used to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0024] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] The Rogowski coil current sensor overcomes many common shortcomings of ordinary current sensors that cannot test large current or high-frequency current due to magnetic saturation.

[0026] The hollow structure of the Rogowski coil without an iron core has the advantages of simple structure, strong anti-interference ability, good linearity, high measurement bandwidth, non-contact, light weight, easy integration, anti-magnetic saturation, low cost and low energy consumption. It has been widely used in different electrical occasions in recent years, measuring currents ranging from a few amperes to several thousand amperes.

[0027] like Figure 1 As shown, Figure 1 Schematic diagram of a typical Rogowski coil current sensor, wherein the typical Rogowski coil current sensor 10 includes: a Rogowski coil 11 and a frame 12 of the Rogowski coil 11, the Rogowski coil 11 is wound around its frame 12, and two output terminals are formed, namely a first output terminal 111 and a second output terminal 112. The typical Rogowski coil current sensor 10 also includes: an integrator 13, such as Figure 2 As shown, Figure 21 is another schematic diagram of a typical Rogowski coil current sensor, wherein the two output ends of the Rogowski coil 11 are connected to the integrator 13. The basic principle of the Rogowski coil current sensor is that the measured current I passes through the skeleton 12 of the Rogowski coil 11, thereby forming an induced potential E in the Rogowski coil 11, and the induced potential E is output to the integrator 13 through the two output ends of the Rogowski coil 11. The induced potential E is integrated by the integrator 13 to form an output voltage Vout proportional to the measured current I.

[0028] Among them, the induced potential E is: μ0 is used to indicate the magnetic permeability of vacuum, N is used to indicate the number of turns of Rogowski coil, and A is used to indicate the cross-sectional area of ​​Rogowski coil. It is used to indicate the differential of current, which is the rate of change of current with respect to time, that is, the instantaneous rate of change of current. H is the mutual inductance coefficient.

[0029] It can be seen from this that when the number of turns of the Rogowski coil remains unchanged, H is a constant, and the induced potential E is Proportional, that is, the output voltage of the Rogowski coil is proportional to the differential of the measured current I. By integrating the induced potential E with an integrator, an output voltage Vout proportional to the measured current I can be obtained.

[0030] In order to ensure that the Rogowski coil can sense the entire current signal of the measured current I in the measured conductor, the Rogowski coil must surround the measured conductor without any interruption.

[0031] There are two existing ways to put the conductor to be measured into the Rogowski coil: the first way is to make the Rogowski coil into a flexible structure that can be bent at will. When in use, the coil is bent, the conductor to be measured is placed, and then one end of the coil is locked, so that the coil is wrapped around the conductor to be measured. The second way is to make the complete Rogowski coil into two semicircular coils, such as Figure 3 As shown, Figure 3 This is a schematic diagram of a typical combination of two coils for measuring current. The two semicircular coils are respectively: a first coil 31 and a second coil 32. By opening the two semicircular coils, the conductor to be measured can be placed in. The two semicircular coils need to be connected by a connecting wire 33. For example, the connecting wire 33 can be a coil or other wire that can conduct a magnetic field.

[0032] However, in the first method, the flexible coil needs to be bent frequently and is easily damaged. In the second method, since the two semicircular coils need to be opened and closed frequently, the connecting wire between the two semicircular coils is easily damaged, which in turn causes the coil to be easily damaged.

[0033] Different from the existing flexible coil and the combination of two semicircular coils, the embodiment of the present application provides a current measuring device, which forms a continuous structure by connecting a moving part to a coil with a gap to measure the current of the measured conductor, thereby achieving control of the current measurement of the measured conductor through the moving part and reducing the loss of the coil during the current measurement process.

[0034] like Figure 4 As shown, Figure 4 A schematic diagram of a current measuring device provided in an embodiment of the present application, the current measuring device 40 includes: a coil 41 that defines an external space and an internal space in a three-dimensional space, the coil 41 having a gap connecting the external space and the internal space; a moving part 42 movably connected to the coil 41, the material of the moving part 42 is a magnetic material; and a current measuring circuit 43 electrically connected to the coil 41.

[0035] The moving component 42 is connected to the coil 41 to form a continuous structure, so that the magnetic field change generated by the measured conductor is converted into a corresponding induced electromotive force E.

[0036] The current measurement circuit 43 receives the induced electromotive force E sensed by the coil 41 and converts it into a current value Iout of the conductor being measured.

[0037] As an example but not limitation, the coil 41 can be used alone or wrapped around a support component for use, such as Figure 4 shown.

[0038] like Figure 5 As shown, Figure 5 This is a schematic diagram of a current measuring device provided in another embodiment of the present application. The moving component 42 and the coil 41 are separated from each other so that the conductor to be measured enters or leaves the internal space through the gap of the coil 41.

[0039] In some embodiments, the moving part 42 includes a magnetic core. The magnetic core is usually made of magnetic materials, such as silicon steel sheets, Permalloy, amorphous materials, manganese-zinc ferrite, and nickel-zinc ferrite.

[0040] In some embodiments, the magnetic permeability of the moving part 42 is greater than a preset value, for example, the preset value is 1000.

[0041] In some embodiments, Figure 4 As shown, when the moving part 42 is connected to the coil 41 to form a continuous structure, part of the magnetic field generated by the measured conductor is transferred to the coil 41 through the moving part 42, so that the coil 41 senses the entire magnetic field generated by the measured conductor.

[0042] For example, when a portion of the conductor to be measured is close to the moving part 42, the magnetic field of this portion of the conductor to be measured is not sensed by the coil 41, but the magnetic field of this portion of the conductor to be measured is transmitted to the coil 41 through the moving part 42, so that the coil 41 senses the entire magnetic field generated by the conductor to be measured.

[0043] In some embodiments, the coil 41 is folded to form a fold and an output end, the fold is far away from the output end to form a gap between the external space and the internal space, and the output end is electrically connected to the current measurement circuit 43 so that the current measurement circuit 43 receives the induced electromotive force sensed by the coil.

[0044] It should be noted that the output end includes the beginning and the end of the coil 41 .

[0045] In some embodiments, Figure 4 As shown, the current measuring device 40 further includes a supporting component 44, and the coil 41 is wound from one end of the supporting component 44 to the other end of the supporting component 44 to form a gap connecting the external space and the internal space.

[0046] In some embodiments, Figure 4 As shown, the coil 41 is folded in half to form a first coil and a second coil. The first coil is wound from one end of the support component 44 to the other end of the support component 44, and the second coil is laid on the surface of the support component 44 and laid from one end of the support component 44 to the other end of the support component 44. The first coil and the second coil form two output ends at the other end of the support component 44, and the two output ends are electrically connected to the current measurement circuit 43, so that the current measurement circuit 43 receives the induced electromotive force E sensed by the coil 41.

[0047] In some embodiments, the support component 44 includes: a component with a notch formed by cutting an annular component; or a component with a notch formed by cutting a hollow component of other shapes; or a component with a notch formed by at least one support component.

[0048] For example, Figure 4 As shown, the support component 44 is a component with a gap formed by cutting an annular component. In another example, at least one support assembly includes three cylinders, and the three cylinders are connected in sequence to form a component with a gap.

[0049] In some embodiments, the current measurement circuit 43 includes: an integration circuit and a current conversion circuit.

[0050] Among them, the coil 41 is electrically connected to the integration circuit, and the integration circuit is electrically connected to the current conversion circuit. The integration circuit is used to integrate the induced electromotive force sensed by the coil 41 to obtain an output voltage proportional to the current in the measured conductor. The current conversion circuit is used to convert the output voltage into the current value of the measured conductor.

[0051] At least one advantageous aspect of the current measuring device provided by the embodiment of the present application is: a coil defining an external space and an internal space in a three-dimensional space; the coil having a gap connecting the external space and the internal space; a moving part movably connected to the coil, the material of the moving part being a magnetic material; a current measuring circuit electrically connected to the coil; wherein the moving part and the coil are separated from each other so that the measured conductor enters or leaves the internal space through the gap of the coil; the moving part is connected to the coil to form a continuous structure so that the magnetic field change generated by the measured conductor is converted into a corresponding induced electromotive force; the current measuring circuit receives the induced electromotive force sensed by the coil and converts it into a current value of the measured conductor, and the moving part is connected to the coil with a gap to form a continuous structure to measure the current of the measured conductor, thereby realizing the control of the current measurement of the measured conductor by the moving part, reducing the loss of the coil during the current measurement process, and the moving part and the coil with a gap can be easily separated from each other, so as to realize the measured conductor entering or leaving the internal space through the gap of the coil, and more conveniently measuring the current of the measured conductor.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the idea of ​​the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A current measuring device, characterized in that: include: A coil that defines an outer space and an inner space in three dimensions; The coil has a gap connecting the external space and the internal space; A moving part movably connected to the coil, wherein the moving part is made of a magnetic material; a current measuring circuit electrically connected to the coil; The moving part and the coil are separated from each other so that the conductor to be measured can enter or leave the internal space through the gap of the coil; The moving part is connected to the coil to form a continuous structure, so that the magnetic field change generated by the measured conductor is converted into a corresponding induced electromotive force; The current measurement circuit receives the induced electromotive force sensed by the coil and converts it into a current value of the conductor being measured.

2. The current measuring device according to claim 1, characterized in that: The moving part includes a magnetic core.

3. The current measuring device according to claim 1, characterized in that: When the moving component is connected to the coil to form a continuous structure, part of the magnetic field generated by the conductor to be measured is transferred to the coil through the moving component, so that the coil senses the entire magnetic field generated by the conductor to be measured.

4. The current measuring device according to claim 1, characterized in that: The current measuring device further includes a supporting member, and the coil is wound from one end of the supporting member to the other end of the supporting member to form a gap connecting the external space and the internal space.

5. The current measuring device according to claim 4, characterized in that: The supporting component includes: a component with a notch formed by cutting an annular component; or a component with a notch formed by cutting a hollow component of other shapes, or a component with a notch formed by at least one supporting component.

6. The current measuring device according to claim 1, characterized in that: The coil is folded in half to form a fold and an output end; The folded portion is away from the output end to form a gap between the external space and the internal space; The output terminal is electrically connected to the current measuring circuit so that the current measuring circuit receives the induced electromotive force sensed by the coil.

7. The current measuring device according to claim 4, characterized in that: The coil is folded in half to form a first coil section and a second coil section; Wherein, the first coil is wound from one end of the supporting component to the other end of the supporting component; The second coil is laid on the surface of the support component and is laid from one end of the support component to the other end of the support component; The first coil segment and the second coil segment form two output terminals at the other end of the supporting component, and the two output terminals are electrically connected to the current measuring circuit so that the current measuring circuit receives the induced electromotive force sensed by the coil.

8. The current measuring device according to claim 1, characterized in that: The current measurement circuit comprises: an integration circuit and a current conversion circuit; The coil is electrically connected to the integration circuit, and the integration circuit is electrically connected to the current conversion circuit; The integrating circuit is used to integrate the induced electromotive force sensed by the coil to obtain an output voltage proportional to the current in the conductor being measured; The current conversion circuit is used to convert the output voltage into the current value of the measured conductor.

9. The current measuring device according to claim 1, characterized in that: The magnetic permeability of the moving part is greater than a preset value.

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