Patent Description:
In electrical components such as a switchgear, heat is usually generated at the locations where components such as busbars, cables, and the contact unit are connected, causing local high temperatures at those locations, namely, hotspots. Monitoring the temperatures of these locations is an important factor in ensuring the safety of electrical components.

Monitoring temperatures of the hotspots typically involves installations of relating apparatus such as sensors, which are vulnerable to possible poor assembly and long overdue operations. Furthermore, as the demand for smart control or monitoring of the electrical components continues to increase, sensors with wireless modules are widely used in the switchgear, especially in the medium voltage switchgear. The wireless module, which is typically integrated with the sensor, can wirelessly transmit data representing the temperature for health condition monitoring.

With the development of technology, the demand for miniaturization of the switchgear is also increasing, which makes it difficult for sensors with integrated wireless modules to be installed at or near hotspots. Even if the sensors with integrated wireless modules can be mounted in a compact space, the high temperature often damages the wireless module due to its proximity to the hotspots.

Document <CIT> describes a passive monitoring device with a temperature sensor and a wireless communication module. When used in the field, a stainless steel cable is used to directly fix the temperature sensor on an isolating switch conductive arm. The stainless steel cable is tightened to ensure that the temperature sensor is in close contact with the isolating switch contact junction.

Embodiments of the present disclosure provide an apparatus for measuring temperature of a switchgear.

In a first aspect, an apparatus for measuring a temperature of a switchgear is provided. The apparatus comprises at least one sensor arranged at or adjacent to a predetermined portion of the switchgear and configured to sense a temperature of the predetermined portion; a transmission module coupled to the at least one sensor via a cable and configured to wirelessly transmit data representing the temperature; and a power module coupled to a busbar of the switchgear and configured to draw power from the busbar by induction and to supply the power to the transmission module and the at least one sensor.

By coupling the sensors to the transmission module via cables, the transmission module can be arranged at more suitable positions away from predetermined positions where high temperature usually occurs. In this way, the layout in switchgear tends to be more reasonable, improving the safety and maintenance efficiency. Furthermore, one transmission module can be coupled to one or more sensors, resulting in low cost and a higher installation efficiency.

In some embodiments, the apparatus further comprises a tube made of copper and serving as at least a part of the busbar, the tube adapted to receive at least a part of the cable and the at least one sensor. With this arrangement, the sensor is able to sense a more accurate temperature due to being closer to the hotspot. In addition, a reduction of external components can effectively reduce the possibility of sharp corner potentials, thereby further improving the safety of the switchgear.

In some embodiments, the apparatus further comprises a housing provided adjacent to the busbar and adapted to receive the transmission module and the power module. This arrangement further facilitates an installation of the transmission module and the power module.

In some embodiments, the power module comprises an induction unit provided around the busbar and configured to draw power from the busbar through the induction; and a voltage regulation unit coupled to the induction unit and configured to regulate voltages to match requirements of the at least one sensor and the transmission module. In this way, the power module can draw power directly from the busbar, eliminating the need for additional batteries or cables and facilitating miniaturization of the apparatus.

In some embodiments, the voltage regulation unit and the transmission module are provided on a printed circuit board. This arrangement increases integration of the apparatus.

In some embodiments, the printed circuit board comprises a through-hole for the busbar to pass through. As a result, the apparatus can be easily mounted to a suitable position on the busbar, further facilitating the installation of the induction unit around the busbar.

In some embodiments, at least one of the housing or the printed circuit board is of a ring shape or a half-ring shape adapted to be detachably arranged around the busbar. In this way, the apparatus can be easily mounted to a suitable position on the busbar while reducing the possibility of concentration of charges at sharp corners.

In some embodiments, each of the at least one sensor comprises a mounting portion adapted to mount the respective sensor in the tube by a fastener; and a sensing circuit enclosed by a thermal glue and adapted to sense the temperature. In this way, the sensor can easily be mounted in the tube, increasing the installation efficiency.

In some embodiments, the apparatus further comprises a mounting module coupled to the tube and configured to facilitate an installation of the tube to the switchgear. This arrangement can improve the stability of the apparatus.

In a second aspect, a method of assembling an apparatus for measuring a temperature of a switchgear is provided. The method comprises arranging at least one sensor at or adjacent to a predetermined portion of the switchgear to sense a temperature of the predetermined portion; coupling a transmission module to the at least one sensor via a cable, and the transmission module adapted to wirelessly transmit data representing the temperature; and coupling a power module to a busbar of the switchgear, and the power module configured to draw power from the busbar by induction and to supply the power to the transmission module and the at least one sensor.

In a third aspect, a switchgear is provided. The switchgear comprising an apparatus as mentioned in the above first aspect.

It is to be understood that the Summary 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 description below.

The above and other objectives, features and advantages of the present disclosure will become more apparent through more detailed depiction of example embodiments of the present disclosure in conjunction with the accompanying drawings, wherein in the example embodiments of the present disclosure, same reference numerals usually represent same components.

The present disclosure will now be discussed with reference to several example embodiments. It is to be understood these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the subject matter.

As used herein, the term "comprises" and its variants are to be read as open terms that mean "comprises, but is not limited to. " The term "based on" is to be read as "based at least in part on. " 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 comprised below. A definition of a term is consistent throughout the description unless the context clearly indicates otherwise.

Health status of electrical apparatuses such as switchgears is one of the most important issues that users are concerned about. Monitoring temperatures of a switchgear as basic data of health status is indispensable in electrical products. Moreover, the demand for temperature monitoring in power distribution switchgear, especially the hotspot of a busbar joint, cable joint, and circuit breaker (CB) arm joint, needs installations of relating components such as sensors, which are vulnerable to the possible poor assembly and long overdue operation.

Furthermore, with the development of technology, sensors with wireless modules are widely used in the switchgear, especially in the medium voltage switchgear. The wireless module, which is typically integrated with the sensor, can wirelessly transmit data representing the temperature for health condition monitoring.

However, for some newly designed switchgear with much more compact space in each compartment, it's difficult to find a clear space for each hotspot to install the sensor integrated with a wireless module, which would also experience high risk in dielectric tests. Even if the sensors with integrated wireless modules could be mounted in a compact space, the high temperature often damages the wireless module due to its proximity to hot spots.

In order to address or at least partially address the above and other potential problems, embodiments of the present disclosure provide an apparatus <NUM> for measuring a temperature of a switchgear <NUM>. <FIG> shows a side view of an apparatus for measuring a temperature of a switchgear according to embodiments of the present disclosure.

As shown, the apparatus <NUM> for measuring a temperature of the switchgear <NUM> according to embodiments of the present disclosure generally comprises at least one sensor <NUM>, a transmission module <NUM> and a power module <NUM> to supply power to the transmission module <NUM> and the at least one sensor <NUM>.

To facilitate monitoring of the temperature of some predetermined portion of the switchgear <NUM> where high temperature typically occurs, at least one sensor <NUM> is arranged at or adjacent to the predetermined portion to sense the temperature thereof.

In contrast to conventional solutions, the sensor <NUM> is separated from the transmission module <NUM>. According to embodiments of the present disclosure, one transmission module <NUM> can be coupled to one or more than one sensor <NUM>. Specifically, the transmission module <NUM> is coupled to at least one sensor <NUM> via a cable <NUM>. In this way, the transmission module <NUM> can obtain data from the at least one sensor <NUM> and wirelessly transmit the data representing the temperature to, for example, a control unit of the switchgear or an external device such as a computer or even a mobile phone.

In this way, the transmission module can be arranged at more suitable positions away from the predetermined positions where the high temperature usually occurs. In this way, the layout in switchgear <NUM> tends to be more reasonable, improving safety and maintenance efficiency. Furthermore, one transmission module can be coupled to one or more sensors, resulting in low cost and higher installation efficiency.

In some embodiments, the data representing the temperature from the sensors may be transmitted in the form of digital pulse signals. For example, in some embodiments, the transmission module or a counting unit thereof can obtain the data representing the temperature by counting the number of pulses over a predetermined time slot. In this way, the data can be transmitted to the transmission module more efficiently and without interference.

It is to be understood that the above embodiments where the data may be transmitted in the form of digital pulse signals are merely illustrative, without suggesting any limitation as to the scope of the present disclosure. Any other suitable means or forms are possible as well. For example, in some alternative embodiments, the data representing the temperature from the sensors may be transmitted in the form of analog signals. In those embodiments, a D/A unit may be provided in the transmission module <NUM> or between the transmission module <NUM> and the sensors <NUM>.

In some embodiments, the transmission module may transmit the data via any appropriate wireless transmission method, comprising but not limited to at least one of Wi-Fi, Bluetooth, Zigbee, Z-wave, Bluetooth Low Energy (BLE), 6LoWPAN, Near Field Communication (NFC), Wi-Fi Direct, Global System for Mobile Communications (GSM), LTE, a NarrowBand Internet of Things (NB-IoT), or LTE-M.

Furthermore, the power module <NUM> can be coupled to the busbar of the switchgear <NUM> to draw power from the busbar by induction. As mentioned above, the power drawn from the busbar can be supplied to transmission module <NUM> and the at least one sensor <NUM> through cables. In this way, no extra power pack, such as a battery is needed, which facilitates the miniaturization of the apparatus <NUM>.

In some embodiments, the power module <NUM> may comprise an induction unit <NUM>. The induction unit <NUM> may be an iron core with coils provided around the busbar. In this way, the induction unit <NUM> can draw power by induction. The induction unit <NUM> may further comprise a voltage regulation unit <NUM> coupled to the induction unit <NUM> to regulate voltages to meet the requirements of the at least one sensor <NUM> and the transmission module <NUM>. For example, the voltage regulation unit <NUM> can convert the magnitude of voltage to <NUM>. 3V for use by sensors <NUM> and transmission modules <NUM>.

The predetermined portions of the switchgear <NUM> as mentioned above may be hotspots of the switchgear <NUM>, which are usually located at busbar joints, cable joints and circuit breaker (CB) arm joints. In some alternative embodiments, alternatively or additionally, the predetermined portions may also be any other suitable locations where the temperature needs to be monitored. Hereinafter, the present disclosure will be described with the sensor being arranged at hotspots as an example, and it is to be understood that it is also possible that the sensor is arranged at other suitable positions.

In some embodiments, the apparatus <NUM> can be used in the existing switchgear with plate-shaped busbars. For example, in each phase of the upper or lower branch, multiple sensors <NUM> may be arranged at or adjacent to the hotspots at busbar joint, cable joint, or CB arm joint. In the meantime, one transmission module <NUM> coupled to the multiple sensors <NUM> via the cable <NUM> may be arranged at a suitable position away from the hotspots. The cable <NUM> and/or the multiple sensors <NUM> may be arranged in additional tubes or sleeves extending along the busbars. This arrangement is more conducive to the modification of existing switchgears to obtain a more accurate temperature measuring.

In embodiments, as shown in <FIG> and <FIG>, the apparatus comprises a tube, optionally made of copper, which can serve as at least a part of the busbar. At least a part of the cables <NUM> and the at least one sensor <NUM> can be arranged in the tube <NUM>, as shown in <FIG> and <FIG>. In this way, the sensor <NUM> can be arranged closer to the hotspots to obtain a more accurate value of the temperature. In some embodiments, all of the cables <NUM> and the at least one sensor <NUM> are arranged in the tube to avoid concentration of charges at sharp corners, improving the stability of the apparatus.

Furthermore, the arrangement of a part of cables <NUM> and sensors <NUM> in the tube reduces the number or sizes of exposed external components. Herein, external components mean that the components are arranged outside the busbars. In order to avoid concentration of charges at sharp corners, in addition to the necessary components, the fewer external components, the better.

According to embodiments of the present disclosure, the reduction of external components can effectively reduce the possibility of concentration of charges at sharp corners, thereby further improving the safety of the switchgear. Furthermore, for the portions of cables or sensors that cannot be hidden in the tube, additional tubes made of other suitable materials may be provided to sleeve the portions of the cables or sensors to avoid concentration of charges at sharp corners.

In order to achieve the above arrangements, for the existing switchgear, the busbar of either upper branch or lower branch may be replaced with the tube made of copper. For example, the apparatus <NUM> as shown in <FIG> and <FIG> may be used to replace the existing plate-shaped busbars of the upper branch. The apparatus <NUM> as shown in <FIG> may be used to replace the busbars of the lower branch, as shown in <FIG> and <FIG>. For the newly developed switchgears, the busbars of either the upper branch or lower branch may directly employ the tube <NUM> made of copper. In this way, the layout in switchgear tends to be more reasonable, improving safety and maintenance efficiency.

In some embodiments, to facilitate installation of the transmission module <NUM> and the power module <NUM>, a housing <NUM> as shown in <FIG> may be provided adjacent to the busbar. The transmission module <NUM> and the power module <NUM> may be arranged in the housing <NUM> to improve integration of the apparatus <NUM>. Furthermore, the housing <NUM> may have rounded chamfers to avoid concentration of charges at sharp corners.

In some embodiments, the voltage regulation unit <NUM> and the transmission module <NUM> may be provided on a printed circuit board <NUM>, as shown in <FIG>. It is to be understood that the positions of the transmission module <NUM> and the voltage regulation unit <NUM> in <FIG> are only schematic. This arrangement can further increase integration of the apparatus <NUM>. In some embodiments, a through-hole <NUM> may be provided on the printed circuit board <NUM> for the busbar to pass through.

As shown in <FIG>, besides the printed circuit board <NUM>, the housing <NUM> also has a through-hole for the busbar to pass through. For example, in some embodiments, at least one of the housing <NUM> or the printed circuit board <NUM> is of a ring shape or a half-ring shape adapted to be detachably arranged around the busbar. As a result, the apparatus <NUM> can be easily mounted to a suitable position on the busbar, further facilitating the installation of the induction unit around the busbar.

To facilitate mounting of the sensor <NUM> in the tube, as shown in <FIG>, in some embodiments, the sensor <NUM> may be substantially plate-shaped with a mounting portion <NUM> at one end and a sensing circuit <NUM> at another end. The mounting portion <NUM> may have a through-hole for a fastener to pass through so that the sensor <NUM> can be mounted in the tube <NUM>.

In some embodiments, the fastener may be, for example, a screw. To facilitate operation of the screw, a through-hole may be provided on a side of the tube <NUM> which is radially opposite to the side where the sensor <NUM> needs to be mounted. In this way, a tool may pass through the through-hole to operate the screw. The sensing circuit <NUM> may be enclosed by a thermal glue to protect the sensing circuit <NUM> while facilitating heat transfer for a more accurate temperature sensing.

To facilitate installation of the tube <NUM> to the switchgear <NUM>, in some embodiments, a mounting module <NUM> may be coupled to the tube <NUM>. As shown in <FIG>, in some embodiments, the mounting module <NUM> may be arranged in the housing <NUM>. The mounting module <NUM> may comprise elements that can be coupled to the corresponding elements arranged in the switchgear <NUM> to mount the tube <NUM> to the switchgear <NUM>.

It can be seen from the above that with the apparatus <NUM> according to embodiments of the present disclosure, one transmission module <NUM> can be coupled to one or more sensors. On the one hand, the number of the transmission module <NUM> is half or less than conventional solutions, reducing costs of the apparatus. On the other hand, the sensor <NUM> without the transmission module has a tiny volume, which is more convenient to be installed in an appropriate location, such as in the tube <NUM>, to obtain more accurate temperature data. Furthermore, the reduction in the number of parts such as transmission module <NUM> also facilitates the installation of the apparatus <NUM> in the switchgear <NUM>.

Embodiments of the present disclosure further provide a method of assembling an apparatus for measuring a temperature of a switchgear. <FIG> shows a flowchart <NUM> illustrating the method. As shown, in block <NUM>, at least one sensor <NUM> is arranged at or adjacent to a predetermined portion of the switchgear to sense a temperature of the predetermined portion.

In block <NUM>, a transmission module <NUM> is coupled to the at least one sensor <NUM> via a cable <NUM>. The transmission module <NUM> can wirelessly transmit data representing the temperature to the modules, such as a control unit at the low voltage side. In block <NUM>, a power module <NUM> is coupled to a busbar of the switchgear <NUM>. The power module <NUM> can draw power from the busbar by induction and supply the power to the transmission module <NUM> and the at least one sensor <NUM>.

Claim 1:
An apparatus for measuring temperature of a switchgear, comprising:
at least one sensor (<NUM>) configured to be arranged at or adjacent to a predetermined portion of the switchgear (<NUM>) and configured to sense a temperature of the predetermined portion;
a transmission module (<NUM>) coupled to the at least one sensor (<NUM>) via a cable (<NUM>) and configured to wirelessly transmit data representing the temperature; and
a power module (<NUM>) configured to be coupled to a busbar of the switchgear (<NUM>) and configured to draw power from the busbar by induction and to supply the power to the transmission module (<NUM>) and the at least one sensor (<NUM>), and
a tube (<NUM>) configured for serving as at least a part of the busbar, the tube (<NUM>) adapted to receive at least a part of the cable (<NUM>) and the at least one sensor (<NUM>).