FIELD
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The present disclosure generally relates to a switchgear, and in particular, to a voltage transformer of the switchgear.
BACKGROUND
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A switchgear is used to switch on or off, control and protect electrical equipment while a power system performs power generation, power transmission, power distribution and electrical energy conversion.
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The internal space of the switchgear is limited so that improvements to components disposed in the switchgear often require a lot of tests and verifications, and how to improve the electrical reliability of the switchgear is an ongoing subject of research. Although some solutions have emerged to improve the electrical reliability of the switchgear, these solutions often require the addition of extra functional components, thus resulting in the need to occupy more space in the switchgear. This makes it necessary to redesign the arrangement in the switchgear in order to accommodate these solutions, or to reduce or discard some of the components in the switchgear to free up space for these improved solutions.
SUMMARY
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The present disclosure is intended to solve one or more of the problems set forth above and/or other potential problems.
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According to a first aspect, there is provided a voltage transformer comprising a housing, a connection terminal, a fuse assembly, and a coil set. The connection terminal is configured to be electrically connected to a first voltage of a first voltage side. The fuse assembly comprises a fuse whose first end is electrically connected to the connection terminal. The coil set is electrically connected to a second end of the fuse and configured to output a second voltage for a second voltage side based on the first voltage, the second voltage being different from the first voltage. Both the connection terminal and the coil set are positioned in the housing adjacent to a first side of the housing. The fuse assembly is positioned in the housing adjacent to a second side of the housing opposite to the first side.
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It is possible to, by employing such an implementation, realize compactness of the voltage transformer while allowing the voltage transformer to have functional characteristics of the fuse. Furthermore, the connection terminal positioned in the housing also allows the output terminal of the corresponding phase of the switchgear connected with the connection terminal to have a protrusion.
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In one or more embodiments, the connection terminal comprises a female connector configured to connect with a male connector for transmitting the first voltage at the first voltage side. With the male/female connectors being connected together, the stability of the circuit connection may be enhanced. The female connector may be in the form of a socket and the male connector may be in the form of a plug.
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In one or more embodiments, the female connector comprises a hollow tapered profile which tapers in a direction from the first side towards the second side. In this manner, the male connector can be inserted into a hollow portion of the female connector, and at a predetermined position a side surface of the male connector can be brought into surface contact with part or all of a side surface of the female connector serving as the tapered profile.
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In one or more embodiments, the fuse comprises a first portion extending along a lengthwise direction, and the fuse assembly further comprises: a first shield for preventing an air gap from discharging, the first shield disposed along the lengthwise direction of the first portion and at least partially covering the first portion. Since an air gap exists between the fuse and the housing, the first shield may function to prevent the air gap from discharging.
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In one or more embodiments, the housing comprises a hole configured to enable the fuse assembly to be accessed from the external of the housing for replacement of the fuse. Such an implementation enables the fuse to be detached for inspection when necessary, or to be replaced when damaged.
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In one or more embodiments, the housing comprises a metallized outer shell. The metallized outer shell may be formed by forming a metal coating of a predetermined thickness by a metal spraying process. The metallic material may comprise a metal or an alloy, and the metal may comprise aluminum or the like.
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In one or more embodiments, the voltage transformer further comprises a plug which is configured to be received by the hole and includes an insulating material. The arrangement of the plug will help prevent the current flowing through the fuse from leaking to the external of the voltage transformer.
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In one or more embodiments, the fuse assembly further comprises: a base configured to abut against one of the first end and second end of the fuse, and a fastening member configured to abut against the other of the first end and second end of the fuse and apply a force to the fuse. In such an implementation, reliable fixation and electrical connection of the fuse can be achieved.
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In one or more embodiments, the fastening member comprises a screw and a nut threadably engaged with each other, the nut being secured to the housing. The engagement of the screw with the nut enables the level of force applied to the fuse to be adjusted and also enables the fuse to be accessed by detachment of the screw to facilitate replacement of the fuse.
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In one or more embodiments, the connection terminal is electrically connected to the fuse via a spring. If there are deviations between actual mounting positions and predetermined positions of the connection terminal and the fuse, the compression of the spring can compensate for the deviations, so that the electrical connection between the connection terminal and the fuse is still achieved.
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In one or more embodiments, the voltage transformer further comprises: a second shield for preventing an air gap from discharging, the second shield is disposed on a side of the connection terminal adjacent to the fuse, and covers at least a portion of the connection terminal. With the second shield being provided, the air gap at the docking interface of the female connector can be prevented from discharging.
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In one or more embodiments, the voltage transformer further comprises a mounting assembly positioned on the first side of the housing, the mounting assembly being configured to secure the housing to a corresponding position in a switchgear. Thus, the voltage transformer can be conveniently fixed.
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According to a second aspect, there is provided a switchgear comprising the voltage transformer according to the first aspect.
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In one or more embodiments, the switchgear comprises an output terminal configured to extend into the housing of the voltage transformer and connect with the connection terminal of the voltage transformer.
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In one or more embodiments, the output terminal comprises a male connector.
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These and other content will become apparent from and elucidated with reference to the drawings and depictions of a plurality of embodiments of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
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The above and other objectives, features, and advantages of example embodiments of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. In the figures, several example embodiments of the present disclosure are shown in an exemplary but non-limiting manner, wherein:
- FIG. 1 illustrates a cross-sectional view of a voltage transformer according to some example embodiments of the present disclosure;
- FIG. 2 illustrates a perspective view of the voltage transformer shown in FIG. 1;
- FIG. 3 illustrates an isometric view of the voltage transformer shown in FIG. 1;
- FIG. 4 illustrates a fuse assembly according to some example embodiments of the present disclosure;
- FIG. 5 illustrates a fastening member shown in FIG. 4; and
- FIG. 6 illustrates a connection terminal and a second shield according to some example embodiments of the present disclosure.
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In all figures, the same or corresponding reference numbers denote the same or corresponding parts.
DETAILED DESCRIPTION OF EMBODIMENTS
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The subject matter described herein will now be discussed with reference to several example embodiments. These embodiments are discussed only to enable those skilled in the art to better understand and thus implement the subject matter described herein, and do not imply any limitation on the scope of the subject matter.
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The terms "comprises" or "include" and variations thereof are to be construed as openended terms that mean "include, but not limited to". The term "or" should be read as "and/or" unless the context clearly dictates otherwise. The term "based on" is to be understood as "based at least in part on". The terms "one embodiment" and "an embodiment" are to be understood as "at least one embodiment". The term "another embodiment" is to be understood as "at least one other embodiment".
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Unless specified or limited otherwise, the terms "connect" and "couple" and variants thereof are used broadly and cover direct and indirect connection and coupling. Furthermore, "connect" and "couple" are not restricted to physical or mechanical connection or coupling. In the following description, the same reference numerals and signs are used to describe the same, similar or corresponding parts in the drawings. Other explicit and implicit definitions may be included below.
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A switchgear may comprise at least one phase for inputting/outputting a corresponding phase voltage/current. The switchgear also comprises other electrical components for operating, switching on or off or changing the corresponding phase voltage/current. For a circuit in at least one phase, a voltage transformer may be configured for changing voltage characteristics. These voltage characteristics comprise a voltage level. A change of the voltage characteristics may be implemented specifically by a coil set (e.g., a plurality of windings) in the voltage transformer.
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Integrating a fuse in the voltage transformer may effectively protect the circuit behind the fuse (as viewed in a current flow direction) and the components on the circuit.
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In view of this, the present disclosure provides a plurality of embodiments regarding a voltage transformer. A fuse is disposed in the voltage transformer, and the arrangement of components in the voltage transformer makes full use of space. Although a voltage transformer is specifically described below with reference to FIG. 1 through FIG. 6, the scope of the present disclosure is not limited in this respect. Variations of embodiments implemented according to the spirit of the present disclosure after understanding the features of the present disclosure should also be considered as falling within the scope of the present disclosure. In addition, although the voltage transformer according to the present disclosure is primarily used for a switchgear, it may also be adapted to form other types of electrical devices.
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FIG. 1 illustrates a cross-sectional view of a voltage transformer. Referring to FIG. 1, a voltage transformer 1 may comprise a housing 10, a connection terminal 11, a fuse assembly 12, and a coil set 13. The connection terminal 11 may be configured to be electrically connected to a first voltage of a first voltage side. The first voltage side may correspond to an input side of a corresponding phase in at least one phase of a switchgear. The first voltage may be a phase voltage of the corresponding phase. The fuse assembly 12 may comprise a fuse 121. A first end of the fuse 121 may be electrically connected to the connection terminal 11. The coil set 13 may be electrically connected to a second end of the fuse 121 and configured to output a second voltage for a second voltage side based on the first voltage, the second voltage being different from the first voltage. The second voltage side may correspond to an output side of the corresponding phase for supplying power to devices downstream in the circuit. In some embodiments, the second voltage is lower than the first voltage. The coil set 13 may comprise a plurality of windings. In some embodiments, the coil set 13 may also comprise a magnetic core. In one embodiment, the voltage transformer 1 further comprises an output interface 19 for outputting the second voltage.
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The fuse 121 may comprise a first portion 1211 extending along a lengthwise direction. The fuse assembly 12 may further comprise a first shield 122 for preventing an air gap from discharging, the first shield 122 disposed along the lengthwise direction of the first portion 1211 and at least partially covering the first portion 1211.
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In one embodiment, the fuse assembly 12 may further comprise a base 123 and a fastening member 124. The base 123 is configured to abut against one of the first end and second end of the fuse 121. The fastening member 124 is configured to abut against the other of the first end and second end of the fuse 121 and apply a force to the fuse 121. In some embodiments, the fastening member 124 comprises a screw 1241 and a nut 1242 threadably engaged with each other, the nut being secured to the housing 10.
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In some embodiments, both the connection terminal 11 and the coil set 13 are positioned in the housing 10 adjacent to a first side 101 of the housing 10, and the fuse assembly 12 is positioned in the housing 10 adjacent to a second side 102 of the housing 10 opposite to the first side.
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In another embodiment, the base 123 may further comprise a spring 1231. The spring 1231 is configured to apply an opposing force to the fuse to cooperate with the fastening member 124 to clamp the fuse 121.
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FIG. 2 illustrates a perspective view of a voltage transformer. Referring to FIG. 2, the connection terminal 11 may comprise a female connector 111. The female connector is configured to connect with a male connector 21 for transmitting the first voltage at the first voltage side. The female connector may be in the form of a socket and the male connector may be in the form of a plug.
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In some embodiments, the female connector 111 may comprise a hollow tapered profile. The tapered profile tapers in a direction from the first side 101 towards the second side 102. In one embodiment, the female connector 111 is sized and shaped to comply with a European standard (EN) (e.g., a technical standard approved by the European Electrotechnical Standardization Committee) or a specification formulated/issued by the International Electrotechnical Commission (IEC).
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In some embodiments, the female connector 111 may also comprise a docking interface 1111. The docking interface 1111 may comprise a snap member for fixing the male connector 21 relative to the housing 1 when the male connector 21 and the female connector 111 are mated for use. The snap member may be coupled to a mechanical switch. The mechanical switch may be configured such that the snap member secures and releases the male connector 21 based on the switching of the mechanical switch. The docking interface 1111 may further comprise a spring for maintaining surface contact between the male connector 21 and the female connector 111 to achieve a stable electrical connection.
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In some embodiments, the voltage transformer 1 may also comprise a second shield 17 for preventing an air gap from discharging. The second shield is disposed on a side of the connection terminal 11 adjacent to the fuse 121, and covers at least a portion of the connection terminal 11. In some embodiments, the second shield 17 may have an annular shape and be arranged to surround at least a portion of the connection terminal 11.
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In some embodiments, the housing 10 further comprises a hole 14. The hole is configured to enable the fuse assembly 12 to be accessed from the exterior of the housing 10 for replacement of the fuse 121. When a state of the fuse needs to be checked or the fuse needs to be replaced, the screw 1241 in the fastening member 124 may be detached via the hole so that the fuse 121 can be accessed, thereby performing the check or replacement of the fuse 121.
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In some embodiments, the fuse 121 may be disposed in a fuse housing, and the fuse 121 comprises one or more fusible elements. The fuse housing having the fuse 121 may be clamped by the base 123 and the fastening member 124. In some embodiments, the fuse housing may comprise a feature, such as a protrusion or a recess, which is disposed on an outer side of the fuse housing and is to be clamped, to help fix the fuse housing having the fuse 121. Such a manner facilitates inspection or replacement of the fuse 121.
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In some embodiments, sand is disposed in the fuse housing. Sand may be used to quench an arc and can also be used to position the fuse. The sand may also separate the plurality of fusible elements from one another when the plurality of fusible elements are disposed in the fuse housing. In some embodiments, the sand comprises quartz sand, and the sand fills most or substantially all of the space in the fuse housing.
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In some embodiments, the voltage transformer 1 may comprise a plug 15. The plug 15 is configured to be received by the hole 14 and comprises an insulating material. In some embodiments, a size of the plug 15 corresponds to that of the hole, and the plug 15 may be fixed to the housing 10 via a screw.
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In some embodiments, a portion of the plug 15 received by the hole 14 is also configured to contact the screw 1241. In other embodiments, the portion of the plug 15 received by the hole 14 is also configured to contact the nut 1242 and not contact the screw 1241. In some embodiments, the size of the portion of the plug 15 received by the hole 14 may be determined by reference to a voltage-size table based on the first voltage. The voltage-size table may be directly provided by a document related to the European Standard (EN), or may be obtained by transforming based on a table directly provided by the document related to the European Standard (EN).
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FIG. 3 illustrates an isometric view of a voltage transformer. Referring to FIG. 3, in some embodiments, the housing 10 comprises a body made of an insulating material and an outer shell 101 surrounding the body and made of a metallic material. The outer shell 101 may be in the form of a coating. The outer shell 101 may be formed by forming a metal coating of a predetermined thickness by a metal spraying process. The metallic material may comprise a metal or an alloy, and the metal may comprise aluminum or the like. The outer shell 101 may be configured to be grounded. In some embodiments, the insulating material may comprise an epoxy resin. The housing 10 is thermoformed according to predetermined positions/spaces of the connection terminal 11, the fuse assembly 12, and the coil set 13.
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In some embodiments, a spring 16 may be used to electrically connect the connection terminal 11 to the fuse 121. When actual mounting positions of the connection terminal 11 and the fuse assembly 12 do not coincide with predetermined positions due to a manufacturing error of the housing 10, a deformation capability of the spring 16 is particularly advantageous in compensating for differences between the actual mounting positions and the predetermined positions of the connection terminal 11 and the fuse assembly 12, because the spring 16 may be stretched or compressed to suit these differences. Similarly, other springs may also be used to electrically connect the fuse 121 to the coil set 13.
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In some embodiments, the voltage transformer 1 may further comprise a mounting assembly 18. The mounting assembly 18 may be positioned at the first side 101 of the housing 10. The mounting assembly may be configured to secure the housing 10 in a corresponding position in the switchgear. In some embodiments, the mounting assembly 18 may have a plurality of through holes. The plurality of through holes comprises a first through hole 181, and the first through hole 181 is configured to hang the housing 10 to a corresponding position in the switchgear by fastening bolts. In one embodiment, the plurality of through holes comprise a second through hole 182. The position of the second through hole 182 corresponds to the connection terminal 11. A size of the second through hole 182 is determined larger than the connection terminal 11/the output terminal 21 so that the output terminal 21 can pass through the second through hole 182 to be electrically connected to the connection terminal 11.
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FIG. 4 illustrates a fuse assembly according to some example embodiments of the present disclosure. Referring to FIG. 4, in some embodiments, the first shield 122 may comprise a cylindrical shape that comprises a hollow portion 1222. In some embodiments, the cylindrical shape may be formed of a metal mesh. The first portion 1211 of the fuse 121 can be received by the hollow portion 1222 of the first shield 122. In some embodiments, the base 123 may comprise a cavity 1232. The cavity 1232 may be used to receive a first end portion of the fuse 121. The spring 1231 shown in FIG. 1 may be disposed in the cavity 1232, and the spring 1231 comprises a free end. The free end of spring 1231 is positioned adjacent to an open side of the cavity 1232.
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In some embodiments, the nut 1242 of the fastening member 124 is configured to abut against the first shield 122. The nut 1242 may also be configured to fix the first shield 122. In some embodiments, a portion of the first shield 122 may be configured to abut against a peripheral portion of the nut 1242.
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In another embodiment, the screw 1241 of the fastening member 124 is configured such that a portion of the screw 1241 can extend into the hollow portion 1222 of the first shield 122 for contacting the second end portion of the fuse 1211 when the screw 1241 is connected to the nut 1242.
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Referring to FIG. 5, in some embodiments, the screw 1241 may comprise a base portion 40 and a projecting portion 41. The projecting portion 41 is disposed along an outer circumference of the base portion 40, and the projecting portion 41 and the base portion 40 may form a cavity 42. The cavity 42 may be used to receive a second end portion of the fuse 121. The screw 1241 may have an external thread 43. In some embodiments, the external thread 43 is disposed on the projecting portion 41.
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In some embodiments, the nut 1242 comprises a base 50. The base 50 has a hollow shape and comprises a cavity 51. The nut 1242 may have an internal threads53 corresponding to the external thread 43. The internal thread 53 may be disposed on an inner side of the base 50. The nut 1242 may also have mounting holes 52 located on the outer side of the base 50 of the nut 1242, and may be configured to fix the nut 1242 with the first shield 122 by mating with fixing screws. For example, when a portion of the first shield 122 abuts against a circumferential portion of the nut 1242, the fixing screws may pass through fixing holes of the first shield 122 and reach and engage the mounting holes 52 on the nut 1242. In some embodiments, the number of fixing holes of the first shield 122 may be multiple, such as three, and in some cases, the number of mounting holes 52 on the nut 1242 may be equal to that of the fixing holes of the first shield 122, and the mounting holes 52 are arranged to align with the fixing holes, respectively.
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In some embodiments, the nut 1242 may comprise a stop portion 53 positioned on the inner side of the base 50. In one embodiment, the stop portion 53 may be disposed at or near an end of the internal thread 53. The stop portion 53 may be configured to inhibit additional movement of the screw 1253 from a first side of the nut 1242 toward a second side of the nut 1242. The stop portion 53 may be integrally formed with the base 50. The stop portion 53 may comprise a continuous section or a discontinuous section protruding from the base 50.
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FIG. 6 illustrates a connection terminal and a second shield according to some example embodiments of the present disclosure. Referring to FIG. 6, in some embodiments, the second shield 17 may have a size corresponding to the female connector 111 of the connection terminal 11. The second shield 17 may also comprise a through hole allowing the spring 16 shown in FIG. 1 to pass therethrough. In some embodiments, the second shield 17 may comprise an electrical connector 1112, such as a spring, to be electrically connected to the male connector 21 and the spring 16. The electrical connector 1112 may be disposed at or near a center of the second shield 17 to facilitate alignment with the male connector 21. Such an implementation can promote stability of the electrical connection.
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The present disclosure further provides a switchgear that may have the voltage transformer described above. In some embodiments, the switchgear may also comprise an output terminal that may be configured to extend into the housing 10 of the voltage transformer 1 and connect with the connection terminal 11 of the voltage transformer 1. In some embodiments, the output terminal may comprise the male connector 21 engaging the female connector 111 described above. In some embodiments, the output terminal corresponds to a voltage in the switchgear.
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The switchgear also enjoys the benefits described with respect to the voltage transformer. For the sake of brevity, a detailed description thereof will be not presented in detail any more.
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Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter specified in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.