Current sensor that can install online and preparation method thereof
Technical field
The present invention relates to the straight-flow system insulation leakagel volume leakage stream detection field in electric system, be specifically related to a kind of can the current sensor and preparation method thereof of weak current in on-line checkingi wire.
Background technology
Sensor is a kind of pick-up unit, measured information can be experienced, and can the information experienced be detected, the information being for conversion into electric signal or other desired forms according to certain rules exports, to meet the requirements such as the transmission of information, process, storage, display, record and control.Current sensor is exactly the sensor can experienced tested electric current and convert usable output signal to.Extracting current signal with current sensor easy and quick, is the technology commonly used in hyundai electronics and electromagnetic technology field.
Distinguish from installation process, current sensor is divided into centre path current sensor and caliper brake current sensor, wherein, of wire must be passed current sensor when centre path current sensor uses, when caliper brake current sensor uses, sensor can be installed from wire centre position.The advantage of centre path current sensor is weak current to be detected accurately, but deficiency is, when installing centre path current sensor, owing to will wire be passed in current sensor hole by one, so will carry out under the condition of open circuit, but some occasion does not allow open circuit.The advantage of caliper brake current sensor is to be convenient to installation and removal, but deficiency is, the iron core of current sensor is made can demolition, installation time, iron core is needed to cut open, so just cause there has been air-gap between iron core, thus magnetic resistance is increased greatly, this makes the measuring accuracy of sensor greatly decline along with the increase of magnetic resistance.
Chinese patent literature CN2691026Y discloses a kind of counter plug type high precision current mutual inductor, what this mutual inductor adopted is sheet lamination mutual-inserting type structure, the core configuration of mutual inductor is two semi-circular shape, each semi-circular shape core body plug connector is formed by stacking by sheet core part intersection, shape in end after superposition becomes interdigitation, to slotting formation cylindrical core body structure during assembling.Although this mutual inductor easy disassembly, but due to by semi-circular shape core body plug connector to time slotting, the connecting portion of semi-circular shape core body also exists small air-gap, and the magnetic permeability of air-gap tens thousand times even hundreds ofs thousand times lower than iron core magnetic conductance, this just makes greatly to increase due to the existence of air-gap the magnetic resistance of annular core element inside after inserting, and then cause the precision of mutual inductor measurement electric current and resolution greatly to decline along with the increase of magnetic resistance, similar with existing caliper brake current transformer, precision and the resolution of counter plug type high precision current mutual inductor disclosed in above-mentioned patent documentation are low, the weak current of on-line measurement microampere order can not be used for.
Summary of the invention
Technical matters to be solved by this invention is caliper brake current transformer of the prior art and counter plug type high precision current mutual inductor owing to there is current transformer precision that air-gap causes the magnetic resistance of current transformer to increase bringing and the lower technical matters of resolution at connecting portion, thus provide a kind of can the current sensor and preparation method thereof of weak current in on-line checkingi wire.
For solving the problems of the technologies described above, the present invention is achieved by the following technical solutions:
A kind of current sensor that can install online is provided, comprises,
Toroidal core, for responding to the magnetic field around at least two wires to be measured; Wherein, described toroidal core is by magnetic band around the on-the-spot coiling of wire to be measured, and after coiling, described wire to be measured is all positioned at described toroidal core; Wherein, at least two wires to be measured are zero without the space combination electromagnetic field under drain conditions;
Coil, winding on described toroidal core, for the magnetic field responded in described toroidal core and generation current signal exports to signal processing circuit;
Signal processing circuit, receives described current signal and the current value processing, calculate described current signal exports to display device;
Display device, receives and shows described current value.
Described magnetic band is slope film alloy strip steel rolled stock.
The thickness of described slope film alloy strip steel rolled stock band is between 8um-10um.
Meanwhile, a kind of method for making of the current sensor that can install online is provided, comprises the steps:
Manufacture toroidal core;
Coiling;
Signalization treatment circuit and display device;
Wherein, manufacture described toroidal core specifically to comprise the steps:
S1: arrange detachable ring skeleton around wire to be measured, arranges rear described wire to be measured and is positioned at described detachable ring skeleton;
S2: form toroidal core at the outside surface coiling magnetic band of described ring skeleton;
S3: seal described toroidal core.
In described step S1, also comprise the steps:
S10: lay housing near wire to be measured, position near described wire to be measured on described housing is provided with mounting hole, and the direction of described mounting hole is vertical with the length direction of described wire to be measured, a semi-circular bracket is inserted in described mounting hole and the two ends of described support is exposed described wire to be measured is wrapped into; And then another one semi-circular bracket and previous semi-circular bracket are installed together, form a complete detachable ring skeleton.
In described step S10, also comprise the step described signal processing circuit and described coil are arranged in described housing, wherein, described coil is arranged around described mounting hole in described housing.
In step S10, described housing is arranged at bottom wire to be measured, and described wire to be measured is placed on described housing upper surface and by described housings support, described mounting hole is arranged near the top of described housing.
In described step S2, described magnetic band is slope film alloy strip steel rolled stock.
The thickness of described slope film alloy strip steel rolled stock band is between 8um-10um.
Technique scheme of the present invention has the following advantages compared to existing technology:
(1) current transformer that can install online of the present invention, comprises toroidal core, and described toroidal core is by magnetic band around the on-the-spot coiling of wire to be measured, and after coiling, described wire to be measured is all positioned at described toroidal core; Wherein, at least two wires to be measured are zero without the external electromagnetic field under drain conditions; Such toroidal core is formed around the on-the-spot coiling of wire to be measured by magnetic band, without the need to power-off of operating a switch when detection, can complete online installation; Simultaneously, described toroidal core is made up of multi-layered magnetic band, fit tightly between adjacent two layers magnetic band, air-gap is there is not in every one deck magnetic recording tape material at its circumferencial direction, the magnetic resistance of described toroidal core is little, and then make the measuring accuracy of the current sensor that can install online of the present invention and resolution higher, possessed the advantage that the high and caliper brake sensor of punching sensor accuracy class can be installed online.
(2) thickness of slope of the present invention film alloy strip steel rolled stock is between 8um-10um, ensure that the flexibility of magnetic conduction band, is convenient to on-the-spot manual coiling, convenient enforcement.
Accompanying drawing explanation
In order to make content of the present invention be more likely to be clearly understood, below in conjunction with accompanying drawing, the present invention is further detailed explanation, wherein,
Fig. 1 is the structural representation of a kind of current sensor that can install online of one embodiment of the invention;
Fig. 2 is the method for making process flow diagram of the toroidal core used in the current sensor can installed online shown in Fig. 1;
Fig. 3 is a kind of structural representation of the housing of one embodiment of the invention;
Fig. 4 is the structural representation after the housing being provided with ring skeleton is opened.
In figure, Reference numeral is expressed as: 1-toroidal core, the detachable ring skeleton of 11-, 12-mounting hole, 2-coil, 3-wire to be measured, 4-signal processing circuit, 5-display device.
Embodiment
As shown in Figure 1, be the structure of a kind of current sensor that can install online of one embodiment of the invention, a kind of current sensor that can install online of one embodiment of the invention comprises:
Toroidal core 1, for responding to the magnetic field around two wires 3 to be measured; Wherein, described toroidal core 1 is by magnetic band around the on-the-spot coiling of wire 3 to be measured, and after coiling, described wire 3 to be measured is all positioned at described toroidal core 1; In the present embodiment, described two wires 3 to be measured, for flowing to and flow out two DC wires of same consumer, are zero at the space combination electromagnetic field without described two wires under drain conditions; As concrete embodiment, described magnetic band is the slope film alloy strip steel rolled stock of thickness between 8um-10um; The thickness of described slope film alloy strip steel rolled stock, between 8um-10um, ensure that the flexibility of magnetic conduction band, is convenient to on-the-spot manual coiling, convenient enforcement.
Coil 2, winding on described toroidal core 1, for the magnetic field responded in described toroidal core 1 and generation current signal exports to signal processing circuit 4.
Signal processing circuit 4, receives described current signal and the current value processing, calculate described current signal exports to display device 5; Wherein need when detecting direct current signal to adopt modulation system, now described signal processing circuit 4 specifically comprises the excitation square wave modulation circuit, shaping circuit and the processor that connect successively, the current signal that described excitation square wave modulation circuit is used for the described coil 2 received exports is modulated, obtain approximate square waves signal, shaping circuit is used for adjusting described approximate square waves signal, draws the square-wave signal of rule; Described processor for receiving described square-wave signal, and calculates current value according to the result of demarcating in advance and described square-wave signal.When processing AC signal, described signal processing circuit 4 specifically comprises filtering circuit, signal amplification circuit and the A/D change-over circuit and CPU that connect successively, the current signal that coil 2 exports exports to CPU after filtering, amplification and A/D conversion, and then CPU calculates current value.
Display device 5, receives and shows described current value.
Certainly as other embodiments of the invention; described toroidal core 1 can by the on-the-spot coiling of the slope film alloy strip steel rolled stock of other thickness; or other can the magnetic band coiling of winding; slope film alloy strip steel rolled stock is just convenient to the magnetic band of coiling the best at present; other same above-described embodiment; can realize object of the present invention equally, belong to protection scope of the present invention.
Such toroidal core 1 is formed around the on-the-spot coiling of wire 3 to be measured by magnetic band, without the need to power-off of operating a switch when installation, can complete on-line checkingi; Simultaneously, described toroidal core 1 is made up of multi-layered magnetic band, fit tightly between adjacent two layers magnetic band, air-gap is there is not in every one deck magnetic recording tape material at its circumferencial direction, the magnetic resistance of described toroidal core 1 is little, so make the measuring accuracy of the current sensor that can install online of the present invention and resolution higher.Possessed the high and caliper brake sensor of punching sensor accuracy class can the advantage of on-line checkingi simultaneously.
The method for making of the current sensor can installed online described in above-described embodiment, comprises the steps:
Make toroidal core 1, described toroidal core 1 is for responding to the magnetic field around at least two wires 3 to be measured; Wherein, described toroidal core 1 is by magnetic band around the on-the-spot coiling of wire 3 to be measured, and after coiling, described wire 3 to be measured is all positioned at described toroidal core 1; Wherein, at least two wires 3 to be measured are zero without the space combination electromagnetic field under drain conditions.
Coiling 2: winding on described toroidal core 1, for the magnetic field responded in described toroidal core 1 and generation current signal exports to signal processing circuit.
Make signal processing circuit and display device, wherein, described signal processing circuit receives described current signal and the current value processing, calculate described current signal exports to display device, and described display device receives and shows described current value.
As a kind of embodiment, shown in Fig. 2, Fig. 3 and Fig. 4, the method for making of described toroidal core 1, specifically comprises the steps:
S1: arrange detachable ring skeleton 11 around two described wires 3 to be measured, arranges rear described wire 3 to be measured and is positioned at described detachable ring skeleton 11; In the present embodiment, described detachable ring skeleton 11 is shaft-like.
As a kind of specific embodiment, around two described wires 3 to be measured, detachable ring skeleton 11 is set, specifically comprise: at two described wire 3 basis rest housings to be measured, described wire to be measured 3 to be placed on described housing upper surface and by described housings support, the top of described housing is provided with mounting hole 12, and the direction of described mounting hole 12 is vertical with the length direction of described wire 3 to be measured, a semi-circular bracket is inserted in described mounting hole 12 and the two ends of described support are exposed described wire 3 to be measured is wrapped into; And then another one semi-circular bracket and previous semi-circular bracket are installed together by grafting, form a complete detachable ring skeleton 11; Further, described signal processing circuit 4 and described coil 2 are arranged in described housing, and described coil 2 is arranged around described mounting hole 12, make the winding of described coil 2 on detachable ring skeleton 11;
S2: form toroidal core 1 at the outside surface coiling magnetic band of described ring skeleton, specifically first one end of described magnetic band is fixed on the outside surface of described ring skeleton, then the other end of magnetic band is completed a circle coiling through described mounting hole 12.
S3: seal described toroidal core 1.
As other method for making of the current sensor that can install online of the present invention; same above-described embodiment of structure of described housing; uniquely unlike; described housing is arranged on directly over described wire to be measured 3 by a cradle hangs; or the side of described wire to be measured 3 is fixed on by stationary installation; can realize object of the present invention equally, belong to protection scope of the present invention.
Be example only by detection two DC wires in above-described embodiment, current sensor can installed online described in invention and preparation method thereof is illustrated, the described current sensor that can install online of the present invention can realize detecting alternating current equally, now, described toroidal core is arranged around three-phase conducting wire, and two adjacent phase conductor phase places are 120 degree of settings.
Obviously, above-described embodiment is only for clearly example being described, and the restriction not to embodiment.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here exhaustive without the need to also giving all embodiments.And thus the apparent change of extending out or variation be still among the protection domain of the invention.