CN1314595A - Current sensor - Google Patents

Abstract

The invention obtains a current sensor which is easy to assemble, requires a small area to mount, has a high measuring accuracy and easily copes with to-be-detected currents of different sizes. A current detector part 17 having through holes of a primary conductor of a three-phase circuit and a zero-phase current detector part 18 are coupled into one body. Three through holes are arranged concentrically, more preferably, at positions of vertices of a triangle. The primary conductor is disposed within the holes. Current outputs from windings 8, 9, 10 of a current transformer are, via a full-wave rectifier circuit 11, converted into voltage signals by a circuit of a plurality of resistors 27 connected in parallel and then output from a terminal 23. The resistors 27 are connected in an optional combination to an output part of the full-wave rectifier circuit 11 by a switch 22.

Description

Current sensor

The application be about application number for " 95100790.4 ", the applying date for " 950222 ", be entitled as dividing an application of " current sensor ".

The present invention relates to be installed on the current sensor that detects electric current, Zero-phase current on the switchboard of control center etc.

7 of Fig. 4 is the current detector of prior art, and among the figure, 1 runs through 3 through holes that the three-phase primary conductor is used respectively for what be a row configuration, and 2 be secondary output end, the 3rd, and the installation foot of installation current detector.

Among Fig. 5 14 is Zero-phase current detecting devices of prior art, and among the figure, 4 are the blanket through hole that runs through primary conductor, and 5 is secondary output end, and 6 for installing the installation foot of Zero-phase current detecting device.

Fig. 6 is the current detector of prior art, the circuit structure diagram of Zero-phase current detecting device, among the figure, 7 is current detector, 8,9,10 is the 3-phase power converter coil, 11 rectification circuits for 8,9,10 outputs of the above-mentioned converter coils of full-wave rectification, 12 are transformed into the output circuit that the resistor 13 of voltage is constituted for the output current with above-mentioned rectification circuit 11.The 14th, the Zero-phase current detecting device, 15 is the zero phase current transformer coil.

Current detector 7 and Zero-phase current detecting device 14 are installed with installation foot 3,6 respectively, and primary conductor passes through hole 1,4 and carries out distribution.

In current detector 7, with the detection electric current that 3-phase power converter coil 8,9,10 detects, by rectification circuit 11 full-wave rectifications, the output circuit 12 that constitutes by resistance 13 is transformed into voltage, exports as voltage signal from terminal 2.

By the detection electric current that the zero phase current transformer coil 15 of Zero-phase current detecting device 14 is detected, export as current signal from terminal 5.

The current sensor of prior art, separately constitute by current detector 7 and Zero-phase current detecting device 14 as mentioned above, when in the switchboard that is secured to control center etc., must install respectively, 3 through holes 1 that the three-phase primary conductor run through current detector 7 respectively, thereafter, the through hole 4 that must run through Zero-phase current detecting device 14 together, it is big that erection space is wanted, and the load current value of current detector 7, each current detector 7 has only a ratings, in order to cooperate the size of sensed current, must prepare the different current detector 7 of several ratings.

The present invention is in order to address the above problem, and its purpose is to provide a kind of assembling to be easy to current sensor.

Still a further object of the present invention provides a kind of current with high accuracy sensor.

Another object of the present invention provides a kind of current sensor that erection space is diminished.

Another purpose of the present invention provides and a kind ofly can be suitable for the different current sensor of tested size of current easily.

Current sensor of the present invention comprises current detector and Zero-phase current detecting device, and described current detector has the 3-phase power converter coil and allows the respective primary conductor to run through the 1st through hole of described current detector; With

Described Zero-phase current detecting device has the 2nd through hole that permission respective primary conductor runs through described Zero-phase current detecting device, wherein, when described Zero-phase current detecting device and when putting on described primary conductor bearing of trend, be formed in the described current detector described the 1st through hole be formed on described Zero-phase current detecting device in corresponding the 2nd through hole align.

Current sensor of the present invention comprises rectification circuit, output circuit and 3-phase power converter coil;

Described rectification circuit is to carrying out full-wave rectification from the detected electric current of described 3-phase power converter coil;

Described output circuit is transformed to output voltage with the output current of described rectification circuit, and described output circuit has a plurality of resistance that are connected to described rectification circuit output by switch in parallel separately.

Current sensor of the present invention, from the through hole that direction is seen primary conductor that runs through of primary conductor, current detector portion becomes same position with the Zero-phase current detector parts.

Again, the through hole with primary conductor is configured on the leg-of-mutton pre-some position.

Again, be provided with detachable composite set on the box, both are combined as a whole respectively laying of current detector portion and Zero-phase current detector parts.

Again, be provided with the switch that output current is transformed into a plurality of resistance of voltage and switches this resistance in the current detector portion, thereby can select to switch elementary rated current.

From the direction that runs through of primary conductor, the through hole of current detector portion and Zero-phase current detector parts is same position, so distribution that need not crooked primary conductor just can be assembled easily.

Again, the through hole of primary conductor is configured on the position of the triangular apex identical with current detector portion, thus during distribution assembling primary conductor can with the operation simultaneously of current detector portion.

Again, current detector portion and Zero-phase current detector parts are respectively laid box and are provided with detachable composite set, and both can be combined into one, so erection space is diminished.

Again, be provided with in the current detector portion output current is transformed into a plurality of resistance that voltage is used, select elementary rated current so that switch so can switch them with switch.

Describe the present invention in detail below in conjunction with the accompanying drawing illustrated embodiment.

Fig. 1 is the oblique view of the current sensor (before installing) of one embodiment of the invention.

Fig. 2 is the circuit structure diagram of the current sensor of one embodiment of the invention;

Fig. 3 is installed separately the circuit structure diagram of state for the current sensor of one embodiment of the invention;

Fig. 4 is the oblique view of the current detector of prior art;

Fig. 5 is the oblique view of the Zero-phase current detecting device of prior art;

Fig. 6 is the current detector of prior art, the circuit structure diagram of Zero-phase current detecting device;

Fig. 7 is the fragmentary cross-sectional view of the portion of closing for one embodiment of the invention.

Embodiment 1

The following describes one embodiment of the invention.Fig. 7 is in the situation that current detector portion 17 and Zero-phase current detector parts 18 are combined being the sectional view of the portion of closing.In Fig. 1, Fig. 7,19 are can the displacement outstanding pawl like the L font of being located at the box end of Zero-phase current detector parts 18,16 for the box side of being located at current detector portion 17 be to close window, the jut of the leading section of pawl 19 be that to close window 16 be to close.This is to close window 16 as shown in Figure 7, with the open communication of the faying face side of the Zero-phase current detector parts 18 of current detector portion 17.

20,21 for the three-phase with the configuration of triangle apex is the through hole that 3 primary conductors run through current detecting part 17, Zero-phase current detector parts 18 respectively, is arranged at the same position (run through direction from primary conductor and be seen as concentric shape) on current detector portion 17, the Zero-phase current detector parts 18.22 for being arranged at the switch of current detector portion 17 fronts, the elementary rated current of selection switching, 23 is the splicing ear of the secondary output of current detector portion 17,24 is the secondary output splicing ear of Zero-phase current detecting device 18,25 for the installation foot of the current sensor that is made of current detector portion 17, Zero-phase current detector parts 18 is installed, and is installed on the substrate (not shown) with (not shown) such as screws.

Because said structure, is to close on the window 16 by pawl 19 hooks like the L font with Zero-phase current detector parts 18 in what be located at current detector portion 17 sides, be combined into one as current sensor, current detector portion 17 and Zero-phase current detector parts 18 be installed in the switchboard as one with installation foot 25.After this, with three-phase promptly 3 primary conductors run through through hole 20,21 and carry out the attaching distribution.

According to said structure,,, install when required area is comparable to be installed respectively little so installation foot 25 can be located at a side separately because current detector portion 17 and Zero-phase current detector parts 18 form one.The comparable prior art of screw number of fastening installation foot 25 few half, assembling operation is also convenient.

Because through hole 20,21 is mutually in concentric position configuration,, assemble easily so need not crooked primary conductor just can finish the distribution of current detector portion 17 and Zero-phase current detector parts 18 with penetrating action.

According to the apex that through hole 20,21 is disposed at triangle, make the magnetic circuit of each phase of three-phase even, so can further improve the precision of instrumentation.

Fig. 2 is the circuit structure diagram of the current sensor of Fig. 1.8,9,10 is the 3-phase power converter coil, 11 is the rectification circuit that full-wave rectification is carried out in the output of above-mentioned converter coils 8,9,10,26 is the ratings commutation circuit that is made of a plurality of resistance 27 and the switch 22 that switches this resistance 27, it is used for selecting to switch elementary rated current, and resistance 27 is used for the output current of above-mentioned rectification circuit 11 is transformed into voltage.15 is zero phase current transformer.The detection electric current that current detector portion 17 usefulness 3-phase power converter coils 8,9,10 detect carries out full-wave rectification by rectification circuit 11, again by a plurality of resistance 27 with switch ratings commutation circuit that the switch 22 of this resistance 27 constitutes 26 it is transformed into voltage signal, from terminal 24 outputs.A plurality of resistance 27 can be respectively same ratings, also can be different ratings, by change-over switch 22, make resistance 27 be single or arranged side by side state, provide necessary predetermined ratings.

By setting above-mentioned ratings commutation circuit 26, as long as change-over switch 22 just can be selected the output level corresponding to elementary ratings electric current, so can be suitable for the different sizes of tested electric current easily with a kind of current sensor.

Embodiment 2

As shown in Figure 3, under the situation that is connected with devices such as transducer between current detector portion 17 and the Zero-phase current detector parts 18, remove current detector portion 17 sides be close window 16 and Zero-phase current detector parts 18 like L font pawl 19 be to close, install after being separated into current detector portion 17 and Zero-phase current detector parts 18.

The present invention as mentioned above owing to be provided with concentric through hole and current detector combines with the Zero-phase current detecting device on current detector and Zero-phase current detecting device, can obtain to assemble easy and the little current sensor of erection space.

Again, the shape through hole is configured in the apex of triangle with one heart, so improved the mensuration precision.

Again,, come the change detection level, so can obtain to be suitable for easily the current sensor that sensed current varies in size with convert resistance by ratings commutation circuit 26 is set.

Claims (1)

1. a current sensor comprises rectification circuit, output circuit, and the 3-phase power converter coil is characterized in that,

Described rectification circuit is to carrying out full-wave rectification from the detected electric current of described 3-phase power converter coil;

Described output circuit is transformed to output voltage with the output current of described rectification circuit, and described output circuit has a plurality of resistance that are connected to described rectification circuit output by switch in parallel separately.

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