Snail-shaped non-intrusive current sensor

Abstract

The utility model provides a snail-shaped non-intrusive current sensor which is an open current clamp and adopts a non-intrusive structure, an iron core is in a state that the front part is narrow and the rear part is wide, the narrow part at the front end is used for operation in a narrow space, and alternating current is collected in the narrow space through a sharp-mouth open gauge outfit; the wide position of the rear end is used for increasing the effective magnetic circuit length of the whole iron core, the main iron core for excitation is placed at the non-opening position, it is ensured that the magnetic circuit length of the iron core at the current signal acquisition position is small, the loop of the iron core is long during working, and the measurement accuracy of the non-intrusive current sensor is improved. And the function of high-precision measurement of an alternating current signal in a narrow space is realized. The iron cores are made of ultracrystalline materials, and the two semicircular iron cores are fixed through the bayonets, so that the operation during field use is facilitated. The device can be used for measuring the sampling current of an electric energy meter in a master control room of a transformer substation, and can also be used for measuring alternating current signals in other narrow spaces.

Description

Technical Field

[0001] The utility model belongs to the technical field of intelligent measurement, and specifically relates to a "snail" shaped non-invasive current sensor. Background Art

[0002] A current sensor is an electrical instrument used to measure current signals. Its measurement accuracy is directly related to the sensing principle. Most of the existing current sensors for measuring AC current signals use the electromagnetic sensing principle, so their measurement accuracy is directly related to the magnetic path length of the iron core. However, the space at some current measurement points is limited, resulting in a small cross-sectional area of ​​the iron core and low measurement accuracy, which does not meet user needs. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a "snail" shaped non-invasive current sensor for measuring AC current signals with high precision in a narrow space.

[0004] The utility model adopts the following technical solution to solve the above-mentioned technical problems: a "snail"-shaped non-invasive current sensor, comprising a pair of upper iron cores and lower iron cores with matching installation end faces; one side of the upper iron core and the lower iron core are both narrowed tips, and corresponding notches are respectively provided on the matching installation end faces of the tips, so that a through hole is formed at the matching installation end faces of the tips when the upper iron core and the lower iron core are matched and installed; the tip with the through hole constitutes an open meter head, which is used to insert the current line to be measured in a narrow space.

[0005] According to the above scheme, the diameter of the other side of the upper iron core and the lower iron core after being installed together is much larger than the diameter of the open meter head, which is used to increase the effective magnetic path length of the iron core.

[0006] Furthermore, the other side of the upper core is in a "half-moon" shape, which becomes a "snail" shape after being installed.

[0007] Furthermore, the other sides of the upper iron core and the lower iron core are both in a "half-moon" shape.

[0008] Furthermore, the other sides of the upper iron core and the lower iron core are both right-angled trapezoids, which together with the open meter head form a triangle after being installed together.

[0009] Furthermore, the other sides of the upper iron core and the lower iron core are both rectangular.

[0010] According to the above scheme, there is an air gap at the front end of the through hole between the matching installation end faces close to the tip direction of the through hole, and there is an air gap at the rear end of the through hole between the matching installation end faces away from the tip direction.

[0011] According to the above scheme, the upper iron core and the lower iron core are fixed by a plurality of opening and closing fixing bayonet holes installed on the iron cores.

[0012] According to the above solution, it further includes a post-stage processing module; the upper iron core and the lower iron core are connected to the post-stage processing module through a transmission cable, and are used to transmit the measured signal to the post-stage processing module through the transmission cable.

[0013] According to the above solution, the post-stage processing module includes an amplification module and a filtering module, which are used to amplify and filter the small current signal, and restore the magnitude of the measured primary current signal according to the transformation ratio of the sensor.

[0014] The beneficial effects of the present utility model are as follows:

[0015] 1. A "snail"-shaped non-invasive current sensor of the present utility model is an open current clamp, adopting a non-invasive structure. The iron core presents a state of being narrow at the front and wide at the back. The "narrow" part at the front is used for operation in a narrow space, and an alternating current is collected in the narrow space through a pointed-nose open head. The "wide" part at the back is used to increase the effective magnetic path length of the entire iron core. The main iron core for excitation is placed at the non-open part, ensuring that the magnetic path length of the iron core at the current signal collection part is small and the iron core loop length is long during operation, improving the measurement accuracy of the non-invasive current sensor; realizing the function of accurately measuring alternating current signals in a narrow space.

[0016] 2. The iron core material of the present utility model adopts ultra-microcrystalline material, and two "semicircular" iron cores are fixed through a bayonet, which is convenient for operation during on-site use.

[0017] 3. The present utility model can be applied to the measurement of the sampling current of the electric energy meter in the main control room of the substation, and can also be used for the measurement of alternating current signals in other narrow spaces. Description of the Drawings

[0018] Figure 1 It is the external view of the embodiment of the present utility model.

[0019] Figure 2 It is the open state diagram of the embodiment of the present utility model.

[0020] Figure 3 It is the closed state diagram of the embodiment of the present utility model.

[0021] Figure 4 It is the front view of the cross-section of the iron core of the embodiment of the present utility model.

[0022] In the figure: 1. Open head; 2. Air gap at the front end of the through-hole; 3. Through-hole; 4. Upper iron core; 5. Air gap at the rear end of the through-hole; 6. Lower iron core; 7. Open and close fixed bayonet; 8. Transmission cable. Detailed Embodiment

[0023] The present utility model will be further described in detail below in conjunction with the drawings and specific embodiments.

[0024] See Figure 1 , this embodiment includes a pair of upper iron cores 4 and lower iron cores 6 with mating mounting end faces; the upper iron core 4 and the lower iron core 6 are made of nanocrystalline materials, and the cross-section of the iron core is as shown in Figure 4 , presenting a state of being narrow in the front and wide in the back. One side of both the upper iron core 4 and the lower iron core 6 is a narrowed tip, and the "narrow" part at the front is used for operation in a narrow space and for clamping the current-carrying wire to be measured; the other side of both is in the shape of a "semicircle", and the "wide" part at the back is used to increase the effective magnetic path length of the entire iron core, for improving the performance of the iron core and enhancing the measurement accuracy of the sensor. Corresponding notches are respectively provided on the mating mounting end faces of the tips, so that a through-hole 3 is formed at the mating mounting end face of the tip when the upper iron core 4 and the lower iron core 6 are matingly mounted; the tips with the through-hole 3 form an open head 1; after the upper iron core 4 and the lower iron core 6 are matingly mounted, they are in the shape of a "snail".

[0025] There is a front air gap 2 of the through-hole between the mating mounting end faces of the through-hole 3 in the direction close to the tip, and there is a rear air gap 5 of the through-hole between the mating mounting end faces in the direction away from the tip.

[0026] The upper iron core 4 and the lower iron core 6 are fixed by opening and closing fixing buckles 7. There are 2 opening and closing fixing buckles 7, which are installed on the iron core.

[0027] The upper iron core 4 and the lower iron core 6 are connected to the post-processing module through a transmission cable 8, and the measured signal is transmitted to the post-processing module through the transmission cable 8. The post-processing module is a general-purpose circuit board, and its function is to amplify and filter the small current signal and restore the magnitude of the measured primary current signal according to the transformation ratio set by the sensor.

[0028] The usage state of this embodiment is as shown in Figure 2 and Figure 3 . When non-intrusive current detection needs to be performed on the current input terminal of a certain electric energy meter, first open the 2 opening and closing fixing buckles 7 to split the sensor into two; then clamp the input current wire of the ammeter to be measured into the through-hole 3, combine the current sensor, and lock the 2 opening and closing fixing buckles 7 to complete the fixation of the sensor; start measuring the current; after the measurement is completed, open the 2 opening and closing fixing buckles 7, remove the input current wire of the ammeter to be measured from the through-hole 3; combine the current sensor, and lock the 2 opening and closing fixing buckles 7.

[0029] The above embodiments are only used to illustrate the design concept and features of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications made according to the principles and design concepts disclosed by the present invention are within the protection scope of the present invention.

Claims

1. A "snail" shaped non-invasive current sensor, characterized in that: It includes a pair of upper iron core and lower iron core with matching installation end faces; one side of the upper iron core and the lower iron core are both narrowed tips, and corresponding notches are respectively provided on the matching installation end faces of the tips, so that when the upper iron core and the lower iron core are matched and installed, a through hole is formed at the matching installation end faces of the tips; the tip with the through hole constitutes an open meter head, which is used to clamp the current line to be measured in a narrow space.

2. A "snail" shaped non-invasive current sensor according to claim 1, characterized in that: The diameter of the other side of the upper iron core and the lower iron core after being installed together is much larger than the diameter of the open meter head, so as to increase the effective magnetic path length of the iron core.

3. A "snail" shaped non-invasive current sensor according to claim 2, characterized in that: The other side of the upper core is in the shape of a "half moon", which becomes a "snail" shape after installation.

4. A "snail" shaped non-invasive current sensor according to claim 2, characterized in that: The other side of the upper core and the lower core are both "half-moon" shaped.

5. The snail-shaped non-invasive current sensor according to claim 2, characterized in that: The other sides of the upper iron core and the lower iron core are both right-angled trapezoids, which together with the open meter head form a triangle after being installed together.

6. A "snail" shaped non-invasive current sensor according to claim 2, characterized in that: The other sides of the upper core and the lower core are both rectangular.

7. The snail-shaped non-invasive current sensor according to claim 1, characterized in that: There is an air gap at the front end of the through hole between the matching installation end faces close to the tip direction of the through hole, and there is an air gap at the rear end of the through hole between the matching installation end faces away from the tip direction.

8. The snail-shaped non-invasive current sensor according to claim 1, characterized in that: The upper iron core and the lower iron core are fixed by a plurality of opening and closing fixing bayonet holes installed on the iron cores.

9. The snail-shaped non-invasive current sensor according to claim 1, characterized in that: It also includes a post-processing module; the upper iron core and the lower iron core are connected to the post-processing module via a transmission cable, so as to transmit the measured signal to the post-processing module via the transmission cable.

10. The snail-shaped non-invasive current sensor according to claim 1, characterized in that: The post-processing module includes an amplification module and a filtering module, which are used to amplify and filter the small current signal, and restore the magnitude of the measured primary current signal according to the transformation ratio of the sensor.

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