A constructive system regarding a capacitance electric voltage sensor comprises a source electrode (110, 210), a shielding tubular body (120, 220), an electric field sensor (130, 230) and a mass of dielectric insulating material (140, 240). The electric field sensor (130, 230) comprises at least one first inner sheet (131, 231) and a second outer sheet (132, 232) superimposed and joined together, wherein said first inner sheet (131, 231) is made by means of a conductive metal material, wherein said second outer sheet (132, 232) is made by means of an electrically insulating material, and wherein said second outer sheet (132, 232) made of insulating material is constrained with respect to the inner face (124, 224) of the shielding tubular element (120, 220).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the US-national stage of PCT application PCT/IT2017/000225 filed 12 Oct. 2017 and claiming the priority of Italian patent application 102016000103234 itself filed 14 Oct. 2016.

FIELD OF THE INVENTION

The present invention relates to a constructive system comprising a capacitive voltage sensor, wherein said sensor detects the electric field generated by a voltage element of the same capacitive sensor, for example, to determine the voltage value of said live element.

More particularly, the present invention relates to a constructive system comprising a capacitive voltage sensor, in which said sensor detects the electric field generated by a voltage element of the same sensor without affecting any surrounding electric and/or magnetic fields, such as, for example, the electromagnetic fields generated by other conductors and/or other nearby bars.

BACKGROUND OF THE INVENTION

At the present the known capacitive voltage sensors have a number of drawbacks.

A first drawback is due to the fact that the resin of dielectric material disposed around the sensor components includes vacuoles (air bubbles) with consequent phenomena of unwanted partial discharges.

Another disadvantage is due to the fact that the same resin is detached from the elements that make up the capacitive sensor with consequent phenomena of unwanted partial discharges.

A third drawback is due to the fact that said resin is not perfectly adherent and/or not perfectly clamped and/or constrained with respect to the organs constituting the capacitive sensor and, therefore, as a result of aging, there are discontinuities between said resin and the organs quoted, with consequent phenomena of unwanted partial discharges. This disadvantage is particularly present when the capacitive sensor is used in an environment where the operating temperature (hot/cold) varies cyclically.

With reference to the facts of the invention, the following documents are cited: WO_2010/070.693.A1, CN_105.588.966.A and U.S. Pat. No. 6,252,388.B1.

Exposure of the Invention

It is therefore the object of the present invention to solve the aforementioned drawbacks.

The invention, which is characterized by the claims, solves the problem of creating a constructive system regarding a capacitive sensor of electric voltage, in which said capacitive sensor extends axially along an axis defined longitudinal, in which said capacitive sensor comprises: >_a source electrode, _in which said source electrode has an elongated shape that extends longitudinally along a longitudinal axis, in which said source electrode configures a first axial end portion and a second axial end portion opposite to the first axial end portion; >_a tubular body shielding, _in which said tubular body shielding has an elongated shape which extends longitudinally along a longitudinal axis, in which said tubular body shielding configures a first axial portion and a second axial portion opposite to said first axial portion, in which said tubular body shielding configures a shell having an inner face and an outer face; >_an electric field sensor, _in which said electric field sensor is positioned radially spaced around said source electrode, _in which said electric field sensor is positioned within said tubular body shielding, _in which said electric field sensor is positioned between the first axial end portion and the second axial end portion; >_a mass of dielectric insulating material, in which said mass is able to encompass said tubular body shielding, said source electrode and said electric field sensor; in which said constructive system is characterized by the fact that said electric field sensor comprises at least a first inner sheet and a second outer sheet overlapped and joined together; by the fact that said first inner sheet is made by an electrically conductive material; by the fact that said second outer sheet is made by an electrically insulating material; by the fact that said second outer sheet made by insulating material is constrained with respect to the inner face of the tubular shielding.

EXEMPLIFYING DESCRIPTION OF SOME PREFERRED EMBODIMENTS

With reference to the accompanying drawings, the constructive system object of the present invention is able to provide a capacitive electrical voltage sensor, wherein said sensor extends along an axis Y defined longitudinal.

With reference toFIGS. 1 and 2, this system substantially comprises a source electrode110/210, a shielding tubular body120/220, an electric field sensor130/230, and a mass of dielectric insulating material140/240.

With reference to said source electrode110/210it has an elongated shape extending longitudinally along a longitudinal axis Y, in such a way as to configure a first axial end portion111/211and a second opposite axial end portion112/212, in which the latter is opposite with respect to the first axial end portion111/211.

With reference to the shielding tubular body120/220, it has an elongate shape extending longitudinally along a longitudinal axis Y, so as to configure a first axial end portion121/221and a second opposite axial end portion122/222.

The shielding tubular body120/220is preferably grounded and it is able to shield the electric field sensor130/230with respect to the field lines generated by live voltage conductors positioned externally with respect to the capacitive sensor, so that the field sensor130/230detects the field lines generated by the source electrode110/210.

Said shielding tubular body120/220comprises a tubular mantle123/223, wherein said mantle123/223, configures an inner face124/224and an outer face125/225with respect to the central axis Y.

With reference to the electric field sensor130/230, said electric field sensor130/230is radially spaced with respect and around said source electrode110/210as well as positioned within said shielding tubular body120/220and preferably positioned in a intermediate point comprised between the first axial end portion121/221and the second axial end portion122/222of said screening tubular body120/220.

With reference to the mass of dielectric insulating material140/240, said mass is able to incorporate the various elements of the sensor and, primarily and substantially, said shielding tubular body130/230, said source electrode110/210and said electric field sensor130/230, in order to positioning said elements and in order to form an electrically insulated carrier structure.

Also referring toFIGS. 3, 4, 5 and 6, said electric field sensor130/230comprises at least one first inner sheet131/231and a second external sheet132/232which are superimposed and joined together, preferably as a monolithic structure, as best described below, wherein the first inner sheet131/231is made by means of an electrically conductive material (metallic) and the second external sheet132/232is made by means of an electrically insulating material.

With reference to the second outer sheet132/232made by insulating material it is preferably bonded to the inner face124/224of the shielding element120/220, for example, by glue points positioned on the outer face of the sheet132/232and on the internal face124/224of the shielding tubular body120/220, or by other systems as described below.

With reference to the first internal sheet131/231made by conductive material, it is able to detect the electric field lines generated by the source electrode110/210and, more particularly, it is intended to form a capacitive coupling between said source electrode110/210and said first sheet131/231.

In this context, said first sheet131/231may take various forms and/or dimensions and/or sizes which can be different with respect to those illustrated in the figures, without departing from the inventive concept of the present invention.

With reference to the second outer sheet132/232made by insulating material, it is able to support the inner sheet131/231in place, as well as able to electrically insulating the inner sheet131/231with respect to the shielding tubular body120/220and therefore, said second sheet132/232may take shapes and/or thickness and/or size and/or conformations different with respect of those illustrated in the Figures without departing from the inventive concept of the present invention.

With particular reference toFIGS. 1A, 2A and 6, the shielding tubular body120/220is provided with first through holes126/226, wherein said first through holes126/226have a width such that the resin can pass through the same first through holes126/226during the casting of the same resin while forming the sensor.

With reference toFIGS. 3, 4 and 5, said electric field sensor130/230is provided with second through holes133/233, wherein said second through holes133/233have a width able to allow the passage of the resin through the same second holes133/233during its casting for forming the sensor.

With particular reference toFIG. 6, said first through holes126/226and said second through holes133/233are axially and mutually communicating, preferably axially aligned with each other, and in any case disposed in such a way as to allow the passage of the resin through said first126/226and said second133/233through holes during the casting of the same resin while forming the sensor.

With reference toFIG. 5, said electric field sensor may further comprise optional fixing means150, which are applied to the external face1331233of the second outer sheet132/232, wherein said fixing means150are designed to form a bond between the second sheet132/232and the inner face124/224of the shielding tubular body120/220.

If the fixing means150are not present, the electric field sensor comprises only the inner sheet131/231and the external sheet132/232, associated with them, provided with through holes133/233, and in this case it is provided to fix the outer foil132/232with respect to and/or against the inner face124/224of the shielding tubular body120/220by points of glue or other systems.

With particular reference toFIGS. 3, 4 and 5, they illustrate in detail a particular electric field sensor130/230, wherein said first inner sheet131/231is provided with respective through holes defined by a respective perimeter134/234, said second outer sheet132/232is provided with respective through holes defined by a respective perimeter135/235, wherein said through holes in said first inner sheet131/231have a greater amplitude than the through holes in the second outer sheet132/232, in such a way as to create between said two perimeters134_135/234_235(i.e., between said two through holes) an annulus136/236of insulating material.

With reference toFIGS. 1 and 2, the capacitive coupling between the source electrode110/210and the electric field sensor130/230detects the electric field generated by the source electrode110/210, and the relative signal by the cable160/260can be transmitted to a processing device170/270, for example to estimate the value of the voltage present in said source electrode110/210.

With reference to the above description, as the electric field sensor130/230is formed by a monolithic body comprising at least one first internal sheet131/231and a second external sheet132/232overlapped and joined together (glued, associated, bound) before of the their insertion into the shielding tubular body120/220, there is no undesirable delamination dislocation/separation between said two sheets, thus solving the above-mentioned problems as well as solving other problems associated with the assembling of the sensor components before the casting, as the electric filed sensor130/230is easily and quickly secured/fixed in position by means of points of glue between the external face137/237of the external sheet132/232of the electric field sensor130/230and the internal face124/224of the shielding tubular body120/220.

With reference to the particular embodiment ofFIG. 6, the resin can pass and flow through the holes133/233executed in the two sheets131/231and132/232of the electric field sensor130/230during its casting, and some resin can also and flow through the holes126/226of the screening tubular body120/220, and in this manner the characteristics of filling and of gripping of the resin are improved, no undesired vacuoles are formed, and no undesired dislocation/separation shall occur between the shielding body120/220and the electric field sensor130/230, thus solving the above-mentioned problems.

The description of the various embodiments of the constructive system for a capacitive sensor are provided solely by ways of non-limiting example, and clearly, therefore, said system can be modified or varied in any way suggested by experience and/or by its use or application within the scope of the following claims. _The following claims also form an integrative part of the above description.