EP4281738A1

EP4281738A1 - Wireless measuring device and cable bushing comprising the same

Info

Publication number: EP4281738A1
Application number: EP21920298.3A
Authority: EP
Inventors: Yanguo CHEN; Lusha ZENG; Jiling LIN; Liqun Huang; Xiushan GE
Original assignee: ABB Schweiz AG
Current assignee: ABB Schweiz AG
Priority date: 2021-01-22
Filing date: 2021-01-22
Publication date: 2023-11-29
Also published as: CN116745590A; WO2022155900A1

Abstract

Embodiments of the present disclosure relate to a wireless measuring device and a cable bushing comprising the same. The wireless measuring device comprises a non-metal package adapted to be arranged inside a cable bushing; and a temperature measuring element arranged inside the non-metal package and being capable of wirelessly communicating with a wireless transmitter arranged outside the cable bushing, the temperature measuring element being configured to detect a temperature inside the cable bushing in response to receiving a measuring signal from the wireless transmitter, and transmit the detected temperature to the wireless transmitter.

Description

WIRELESS MEASURING DEVICE AND CABLE BUSHING COMPRISING THE SAME

FIELD

Embodiments of the present disclosure generally relate to the field of switchgear, and more particularly, to a wireless measuring device and a cable bushing comprising the same.

BACKGROUND

Cable bushings are typically used on a switchgear to deliver power from an external cable to the switchgear. Due to potential improper installation of the external cable and the cable bushing, a contact resistance at a connection point therebetween can be very large, resulting in a much larger amount of heat being generated at the connection point than expected. The generated heat would cause a high temperature rise at the connection point, which would adversely affect the performance of the cable and cable bushing or even damage them. Thus, there is a need for an approach for carrying out a direct temperature measurement in the cable bushing so as to monitor operating conditions of the cable bushing in real time.
SUMMARY
In view of the foregoing problems, various example embodiments of the present disclosure provide a wireless measuring device and a cable bushing comprising the same to measure the temperature inside the cable bushing in a manner of high safety, high efficiency and high reliability.
In a first aspect of the present disclosure, example embodiments of the present disclosure provide a wireless measuring device. The wireless measuring device comprises a non-metal package adapted to be arranged inside a cable bushing; and a temperature measuring element arranged inside the non-metal package and being capable of wirelessly communicating with a wireless transmitter arranged outside the cable bushing, the temperature measuring element being configured to detect a temperature inside the cable bushing in response to receiving a measuring signal from the wireless transmitter, and transmit the detected temperature to the wireless transmitter. With these embodiments, the wireless measuring device can be preinstalled in the cable bushing. In this way, the temperature of the cable bushing can be measured in a wireless manner, and thus the safety of the cable bushing can be improved.
In some embodiments, the non-metal package is of a cylindrical shape and comprises an external thread formed on a side surface of the non-metal package and adapted to be screwed onto the cable bushing; and an inner hole formed at an end of the non-metal package and adapted to be actuated by a tool to mount the wireless measuring device into the cable bushing or dismount the wireless measuring device from the cable bushing. With these embodiments, the wireless measuring device can be installed into the cable bushing in a detachable manner, and thus the wireless measuring device can be easily replaced.
In some embodiments, the inner hole is of a polygonal shape. With these embodiments, the wireless measuring device can be mounted into the cable bushing or dismounted from the cable bushing easily by using existing tools.
In some embodiments, the non-metal package is made of ceramics or polymers. With these embodiments, the temperature measuring element can be integrated into the non-metal package easily and protected by the non-metal package reliably.
In some embodiments, the temperature measuring element comprises an RFID IC. With these embodiments, the RFID IC is a passive device without need of an additional power supply. Thus, the size of the wireless measuring device can be decreased and the safety of the cable bushing would be further improved. Moreover, the RFID IC could communicate with the wireless transmitter by using a signal containing an individual ID, and thus the signals from different RFID ICs can be distinguished from each other easily.
In a second aspect of the present disclosure, example embodiments of the present disclosure provide a cable bushing. The cable bushing comprises an insulating section adapted to be mounted onto a switchgear; a conductor arranged in the insulating section and adapted to deliver power from an external cable to the switchgear; a connecting hole formed in the conductor and adapted to be connected to the external cable; a wireless measuring device according to the first aspect of the present disclosure arranged inside the connecting hole; and at least one signal emission hole extending from a side wall of the connecting hole to an external surface of the conductor near to the wireless measuring device. With these embodiments, the cable bushing comprises the wireless measuring device as described above, and thus could provide analogous advantages. Moreover, the detected temperature could be reliably transmitted to the wireless transmitter via the at least one signal emission hole.
In some embodiments, the connecting hole comprises an internal thread adapted to be connected to the wireless measuring device and the external cable. With these embodiments, the wireless measuring device and the external cable can be mounted into the cable bushing or dismounted from the cable bushing easily by using existing tools.
In some embodiments, the at least one signal emission hole comprises two signal emission holes arranged opposite to each other with respect to the connecting hole. With these embodiments, more communication paths are provided, and the wireless signal can be more reliably communicated between the wireless measuring device and the wireless transmitter.
In some embodiments, the conductor is made of copper.
In some embodiments, the insulating section is made of epoxy.
In some embodiments, the at least one signal emission hole is filled with the same material as the insulating section.
It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.
DESCRIPTION OF DRAWINGS
Through the following detailed descriptions with reference to the accompanying drawings, the above and other objectives, features and advantages of the example embodiments disclosed herein will become more comprehensible. In the drawings, several example embodiments disclosed herein will be illustrated in an exemplary and in a non-limiting manner, wherein:
FIG. 1 is a schematic view illustrating a wireless measuring device in accordance with an embodiment of the present disclosure;
FIG. 2 is a front view of the wireless measuring device as shown in FIG. 1; and
FIG. 3 is a schematic view illustrating a cable bushing in accordance with an embodiment of the present disclosure.
Throughout the drawings, the same or similar reference symbols are used to indicate the same or similar elements.
DETAILED DESCRIPTION OF EMBODIEMTNS
Principles of the present disclosure will now be described with reference to several example embodiments shown in the drawings. Though example embodiments of the present disclosure are illustrated in the drawings, it is to be understood that the embodiments are described only to facilitate those skilled in the art in better understanding and thereby achieving the present disclosure, rather than to limit the scope of the disclosure in any manner.
The term “comprises” or “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “or” is to be read as “and/or” unless the context clearly indicates otherwise. The term “based on” is to be read as “based at least in part on. ” The term “being operable to” is to mean a function, an action, a motion or a state can be achieved by an operation induced by a user or an external mechanism. The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below. A definition of a term is consistent throughout the description unless the context clearly indicates otherwise.
According to embodiments of the present disclosure, a wireless measuring device and a cable bushing comprising the same are provided so as to realize the direct temperature measuring inside a cable bushing in a wireless manner. The above idea may be implemented in various manners, as will be described in detail in the following paragraphs.
Hereinafter, the principles of the wireless measuring device of the present disclosure will be described in detail with reference to FIGS. 1-2. Referring to FIG. 1 first, FIG. 1 is a schematic view illustrating a wireless measuring device in accordance with an embodiment of the present disclosure. As shown in FIG. 1, the wireless measuring device 100 generally includes a non-metal package 101 and a temperature measuring element 102.
The non-metal package 101 is adapted to be arranged inside a cable bushing 200, as will be described in detail hereinafter with reference to FIG. 3. The non-metal package 101 is arranged to fix and protect the temperature measuring element 102 inside it. A wireless signal can be transmitted through the non-metal package 101.
In some embodiments, the non-metal package 101 is of a cylindrical shape for easy mounting. In other embodiments, the non-metal package 101 can be of other shapes, such as a spherical shape. The scope of the present disclosure is not intended to be limited in this respect.
In some embodiments, the non-metal package 101 is made of ceramics or polymers. The ceramics or polymers can be casted with the temperature measuring element 102. Thus, the temperature measuring element 102 can be integrated into the non-metal package 101 easily and reliably protected by the non-metal package 101. In other embodiments, the non-metal package 101 can be made of other encapsulating materials. The scope of the present disclosure is not intended to be limited in this respect.
As shown in FIG. 1, the temperature measuring element 102 is arranged inside the non-metal package 101 and is capable of wirelessly communicating with a wireless transmitter arranged outside the cable bushing 200. The temperature measuring element 102 is configured to detect a temperature inside the cable bushing 200 in response to receiving the measuring signal from the wireless transmitter, and transmit the detected temperature to the wireless transmitter.
In some embodiments, the temperature measuring element 102 includes a RFID IC. In other embodiments, the temperature measuring element 102 may include components suitable for transferring signals according to other communication protocols, for example, Zigbee, SAW, and so on. The scope of the present disclosure is not intended to be limited in this respect.
FIG. 2 is a front view of the wireless measuring device as shown in FIG. 1. In an embodiment, as shown in FIG. 2, the wireless measuring device 100 further includes an external thread 104 and an inner hole 103. The external thread 104 is formed on a side surface of the non-metal package 101 and adapted to be screwed into the cable bushing 200. The inner hole 103 is formed at an end of the non-metal package 101 and adapted to be actuated by a tool to mount the wireless measuring device 100 into the cable bushing 200 or dismount the wireless measuring device 100 from the cable bushing 200. If the wireless measuring device 100 is broken, it can be easily replaced in this detachable installing manner.
In some embodiments, the inner hole 103 is of a polygonal shape, for example, a hexagonal shape. The wireless measuring device 100 can be installed into the cable bushing by using existing tools to operate the inner hole 103. Thus, there is no need to prepare specific tools for installing the wireless measuring device 100. In other embodiments, the inner hole 103 can be of another shape, for example, triangular shape, rectangular shape, and so on. The scope of the present disclosure is not intended to be limited in this respect.
With the arrangement as shown in FIGS. 1-2, the wireless measuring device 100 can be easily mounted inside the cable bushing. Compared with conventional temperature measuring approaches, the wireless measuring device 100 of the present disclosure is in direct contact with the inside of the cable bushing. Accordingly, the temperature inside the cable bushing can be measured accurately.
Hereinafter, an operating principle of the cable bushing of the present disclosure will be described in detail with reference to FIG. 3. FIG. 3 is a schematic view illustrating a cable bushing in accordance with an embodiment of the present disclosure. As shown in FIG. 3, the cable bushing 200 generally includes an insulating section 201, a conductor 202, a connecting hole 203, a wireless measuring device 100, and at least one signal emission hole 204.
The insulating section 201 is adapted to be mounted onto a switchgear. The insulting section 201 is configured to provide an insulating protection for electrical components inside the cable bushing 200, and a wireless signal can be transmitted through the insulating section 201.
In some embodiments, the insulating section 201 is made of epoxy. In other embodiments, the insulating section 201 is made of other insulating materials. The scope of the present disclosure is not intended to be limited in this respect.
The conductor 202 is arranged in the insulating section 201 and adapted to deliver power from an external cable to the switchgear. One end of the conductor 202 is arranged outside the switchgear, and the other end of the conductor 202 is arranged inside the switchgear.
In some embodiments, the conductor 202 is made of copper. In other embodiments, the conductor 202 is made of other metals, for example, aluminum. The scope of the present disclosure is not intended to be limited in this respect.
The connecting hole 203 is formed on one end of the conductor 202 outside the switchgear and adapted to be connected to the external cable. The external cable can be connected to the connecting hole 203 in a detachable manner or through an interference fit. In some embodiments, the connecting hole 203 comprises an internal thread adapted to be connected to the wireless measuring device 100 and the external cable. With such an arrangement, the wireless measuring device 100 and the external cable can be mounted into the cable bushing 200 or dismounted from the cable bushing 200 easily by using existing tools.
The wireless measuring device 100 according to embodiments of present disclosure is arranged inside the connecting hole 203. It is to be understood that the wireless measuring device 100 should be mounted in the connecting hole 203 before the external cable is connected to the connecting hole 203, and the wireless measuring device 100 should be mounted in the connecting hole 203 at a deeper position than the external cable to make sure the connecting hole 203 has enough room for the external cable to be inserted.
As shown in FIG. 3, the at least one signal emission hole 204 extends from a side wall 205 of the connecting hole 203 to an external surface 206 of the conductor 202 near to the wireless measuring device 100. The signal emission hole 204 is configured to provide a communication path for the wireless signal. If there is no signal emission hole 204 in the conductor 202, the wireless signal would be hardly communicated between the wireless measuring device 100 and the wireless transmitter because of an electromagnetic shielding effect of the metal connecting hole 203.
In some embodiments, the signal emission hole 204 is filled with the same material as the insulating section 201, for example, epoxy, and so on. In other embodiments, the signal emission hole 204 can be empty. The scope of the present disclosure is not intended to be limited in this respect.
In some embodiments, the at least one signal emission hole 204 comprises two signal emission holes 204 arranged opposite to each other with respect to the connecting hole 203, so as to provide more communication paths for the wireless measuring device 100. However, it is to be understood that in other embodiments, only one signal emission hole 204 or more than two signal emission holes 204, for example, three, four, and more signal emission holes, may be provided on the conductor 202. The scope of the present disclosure is not intended to be limited in this respect.
When measuring the temperature inside the cable bushing 200, the wireless transmitter transmits a measuring signal. The measuring signal passes through the insulating section 201 and arrives at the wireless measuring device 100 through the signal emission hole 204. In response to receiving the measuring signal, the wireless measuring device 100 measures the temperature inside the cable bushing 200, and transmits the detected temperature to the wireless transmitter through the signal emission hole 204 and the insulating section 201.
In embodiments that the wireless measuring device 100 comprises an RFID IC, the wireless measuring device 100 draws the energy needed for its operation from a magnetic field provided by the wireless transmitter. Thus, a power of several dozen to hundreds of microwatts can be used inside the RFID IC.
When there is a plurality of cable bushings in the switchgear, the temperatures of these cable bushings need to be distinguished from each other so as to recognize which cable bushing each temperature belongs to. By using RFID ICs, the distinguishing of the temperatures can be achieved, because each RFID IC has an individual ID corresponding to a specific cable bushing, and the output signal of the RFID IC indicates the temperature of the corresponding cable bushing and contains the individual ID. When the wireless transmitter receives the output signal from the RFID IC, the wireless transmitter will recognize which cable bushing the temperature belongs to. Accordingly, by using the RFID IC, the temperature measuring is achieved with a higher efficiency.
Compared with wired types of sensors, the RFID IC is a passive device without need of an additional power supply. Thus, the size of the wireless measuring device 100 can be decreased and the safety of the cable bushing would be further improved.
With the arrangement of the cable bushing as shown in FIG. 3, the wireless temperature measuring inside the cable bushing can be achieved. Compared with the conventional cable bushing, the cable bushing of the present disclosure contains the wireless measuring device. Accordingly, the high temperature of the cable bushing resulting from the loose connection of the cable bushing and the external cable can be monitored in real-time.
While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

Claims

A wireless measuring device (100) comprising:

a non-metal package (101) adapted to be arranged inside a cable bushing (200) ; and

a temperature measuring element (102) arranged inside the non-metal package (101) and being capable of wirelessly communicating with a wireless transmitter arranged outside the cable bushing (200) , the temperature measuring element (102) being configured to detect a temperature inside the cable bushing (200) in response to receiving a measuring signal from the wireless transmitter, and transmit the detected temperature to the wireless transmitter.
The wireless measuring device (100) according to claim 1, wherein the non-metal package (101) is of a cylindrical shape and comprises:

an external thread (104) formed on a side surface of the non-metal package (101) and adapted to be screwed onto the cable bushing (200) ; and

an inner hole (103) formed at an end of the non-metal package (101) and adapted to be actuated by a tool to mount the wireless measuring device (100) into the cable bushing (200) or dismount the wireless measuring device (100) from the cable bushing (200) .
The wireless measuring device (100) according to claim 2, wherein the inner hole (103) is of a polygonal shape.
The wireless measuring device (100) according to claim 1, wherein the non-metal package (101) is made of ceramics or polymers.
The wireless measuring device (100) according to claim 1, wherein the temperature measuring element (102) comprises an RFID IC.
A cable bushing (200) comprising:

an insulating section (201) adapted to be mounted onto a switchgear;

a conductor (202) arranged in the insulating section (201) and adapted to deliver power from an external cable to the switchgear;

a connecting hole (203) formed in the conductor (202) and adapted to be connected to the external cable;

a wireless measuring device (100) according to any of claims 1-5 arranged inside the connecting hole (203) ; and

at least one signal emission hole (204) extending from a side wall (205) of the connecting hole (203) to an external surface (206) of the conductor (202) near to the wireless measuring device (100) .
The cable bushing (200) according to claim 6, wherein the connecting hole (203) comprises an internal thread adapted to be connected to the wireless measuring device (100) and the external cable.
The cable bushing (200) according to claim 6, wherein the at least one signal emission hole (204) comprises two signal emission holes (204) arranged opposite to each other with respect to the connecting hole (203) .
The cable bushing (200) according to claim 6, wherein the conductor (202) is made of copper.
The cable bushing (200) according to claim 6, wherein the insulating section (201) is made of epoxy.
The cable bushing (200) according to claim 6, wherein the at least one signal emission hole (204) is filled with the same material as the insulating section (201) .