CN218471747U - Current transformer and power distribution system - Google Patents

Abstract

The application discloses current transformer and distribution system relates to electric power system technical field, the current transformer of this application, including the sub-casing of two relative settings, the connection can be dismantled to two sub-casings, sub-casing includes a plurality of semi-ring shells that have the open-ended, the opening is located between the arm of semi-ring shell, semi-ring shell inside has the annular chamber and is located the export at annular chamber both ends, the opening orientation of a plurality of semi-ring shells is connected with one side and along an open-ended lateral wall style of calligraphy, constitute a plurality of annular shells after two relative sub-casing connections that set up, wherein be provided with the iron core in the annular chamber of a sub-casing respectively and around establishing the winding on the iron core. The application provides a current transformer need not cut off the cable at the in-process of installation, can make things convenient for current transformer's installation.

Description

Current transformer and power distribution system

Technical Field

The application relates to the technical field of electric power systems, in particular to a current transformer and a power distribution system.

Background

In recent years, the national power grid provides a task target for intelligent power grid construction, and a plurality of power supply companies gradually develop automatic transformation construction projects of the power distribution network. In the automatic transformation of a distribution network, a group of current transformers (two groups of current transformers are arranged in a double-cable mode) and a group of fault addressers are required to be arranged on cable heads in an incoming and outgoing line high-voltage cabinet of a distribution automation three-remote station. The current transformer is used for measuring three-phase current in the high-voltage cabinet, and the measurement accuracy is high. The fault addresser is used for detecting line faults and has a large measuring range, wherein the current transformer is an instrument for converting large primary side current into small secondary side current according to the electromagnetic induction principle to measure, is composed of a closed iron core and a winding wound on the iron core, and can convert primary current with a larger value into secondary current with a smaller value through a certain transformation ratio to realize the purposes of protection, measurement and the like. For example, a 400/5 current transformer can convert the actual 400A current into 5A current.

The current transformer used for distribution network automation in the prior art needs to terminate primary current when being installed, and cut off a cable, so that the cable passes through the current transformer. In such an installation method, since the power supply needs to be cut off, the installation of the current transformer is difficult, and the power supply cut off has a great influence on the social electricity utilization.

SUMMERY OF THE UTILITY MODEL

An object of the application is to provide a current transformer, need not cut off the cable at the in-process of installation, can make things convenient for current transformer's installation.

The embodiment of the application provides a current transformer on the one hand, including two subshells that set up relatively, two subshells can dismantle the connection, the subshells includes a plurality of semi-ring type shells that have the opening, the opening is located between the arm of semi-ring type shell, semi-ring type shell inside has the annular chamber and is located the export at annular chamber both ends, the opening orientation of a plurality of semi-ring type shells is connected with one side and along an open-ended lateral wall style of calligraphy, constitute a plurality of annular shells after two subshells that set up relatively connect, wherein the annular chamber of a subshell is provided with the iron core respectively and winds the winding of establishing on the iron core.

As a practical way, an insulating material is provided in the annular cavity to fix the core and the windings to the inner wall of the half-ring type shell.

As one practicable, the insulating material includes an epoxy resin.

As a practical manner, the connection portions are respectively provided at opposite sides of the opening of the half-ring shells, and adjacent two half-ring shells are connected by the connection portions.

As an implementation manner, the two sub-housings oppositely arranged are detachably connected through a connecting piece, and the connecting piece comprises a bolt, a hose clamp or a steel belt.

As an implementation mode, a plurality of fixing grooves are fixedly arranged on the inner side wall of the annular shell, and an ohm ring is fixedly arranged on the fixing grooves and used for fixing a cable penetrating through the annular shell.

As a practical manner, the plurality of fixing grooves are uniformly distributed on the inner side wall of the annular shell.

As a practical way, the half-ring shell provided with the iron core is provided with a connecting terminal corresponding to the winding, or the half-ring shell provided with the iron core is provided with a wire outlet corresponding to the inlet and outlet of the winding.

As a practical manner, the ring-shaped shell includes two or three.

Another aspect of the present invention provides a power distribution system including a power supply having multi-phase power, and the above-mentioned current transformer, wherein each phase power cable of the power supply respectively passes through a ring-shaped shell of the current transformer.

The beneficial effects of the embodiment of the application include:

the utility model provides a current transformer, including two sub-casings that set up relatively, two sub-casings can dismantle the connection, sub-casing includes a plurality of semi-ring type shells that have the opening, the opening is located between the arm of semi-ring type shell, semi-ring type shell inside has the annular chamber and is located the export at annular chamber both ends, the opening orientation of a plurality of semi-ring type shells is with one side and along the linear connection of open-ended lateral wall, two sub-casings that set up relatively constitute a plurality of annular casings after connecting, wherein, the number of annular casing corresponds the setting with the cable number in the power, the cable in the power passes the passageway that the annular casing formed respectively, wherein be provided with the iron core respectively in the annular chamber of a sub-casing and wind the winding of establishing on the iron core, the cable in the power is as current transformer's primary coil, the winding is as secondary coil, can obtain the current value on the primary coil through current information that detects on the secondary coil and the number of turns ratio of primary coil and secondary coil, namely the current value in the power cable. When the current transformer is installed, the sub-shells which are arranged oppositely only need to be close to each other from the two sides of the power cable respectively, so that the power cable is located behind the channel formed by the annular shell, the sub-shells on the two sides are fixedly connected, the power cable does not need to be cut off, and the current transformer is convenient and fast to install.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is a schematic structural diagram of a current transformer according to an embodiment of the present disclosure;

fig. 2 is a second schematic structural diagram of a current transformer according to an embodiment of the present disclosure;

fig. 3 is a third schematic structural diagram of a current transformer according to an embodiment of the present application.

Icon: 100-a current transformer; 110-a sub-shell; 111-a semi-ring shell; 112-ring-shaped shell; 120-iron core; 130-winding; 140-an insulating material; 150-a connecting portion; 160-fixed groove; 170-ohm circle.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, as presented in the figures, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present application, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and in a manner that will allow those of ordinary skill in the art to understand in detail the specific meaning of the terms in the present application.

With the construction of distribution automation, a current transformer is configured in an opening and closing station, a ring main unit, a combined box transformer and a cable tapping box to measure the current value of each cable in a power supply. When a current transformer is installed on site, the current transformer needs to be installed after power failure of a line, but actually, the power failure has a great influence on the society, so that certain problems often exist.

The embodiment of the present application provides a current transformer 100, as shown in fig. 1, fig. 2 and fig. 3, the current transformer includes two sub-housings 110 disposed opposite to each other, the two sub-housings 110 are detachably connected, each sub-housing 110 includes a plurality of half-ring shells 111 having openings, the openings are located between the arms of the half-ring shells 111, the inside of each half-ring shell 111 has an annular cavity and outlets located at two ends of the annular cavity, the openings of the plurality of half-ring shells 111 face the same side and are connected in a linear shape along the side walls of the openings, the two sub-housings 110 disposed opposite to each other are connected to form a plurality of ring shells 112, and an iron core 120 and a winding 130 wound around the iron core 120 are disposed in the annular cavity of one sub-housing 110.

The current transformer 100 provided by the embodiment of the application, when installing, set up two sub-housings 110 in the both sides of cable, then be close to each other, at the in-process that is close to each other, make each cable be located the opening part of semi-ring type shell 111 respectively in the power, the export of the semi-ring type cavity of sub-housing 110 until both sides is hugged closely relatively, make the semi-ring type shell 112 of constituting of semi-ring type shell 111 both sides, at this moment, adopt the connecting piece to connect the sub-housing 110 of both sides fixed and can accomplish the installation of current transformer 100, be about to each cable setting of power in the passageway that the corresponding ring type shell 112 encloses when two sub-housings 110 are close to each other, need not cut the cable of cable, thereby avoided cutting the problem of having a power failure that the cable brought.

It should be noted that, as will be known to those skilled in the art, when the current transformer 100 converts a primary current into a secondary current, the primary current needs to pass through the toroidal core 120, so that the core 120 and the winding 130 are disposed in the toroidal cavity of one of the sub-housings 110, the core 120 extends into a half-toroidal core 120 along the toroidal cavity, the half-toroidal core 120 is also disposed in the toroidal cavity of the other sub-housing 110, and the two half-toroidal cores 120 are disposed opposite to each other to form the toroidal core 120.

When the current transformer 100 provided by the embodiment of the application is used, each cable in the power supply respectively passes through the channel enclosed by the annular shell 112, and the annular iron core 120 is arranged in the annular shell 112, so that each cable in the power supply respectively passes through the center of the annular iron core 120 to be used as a primary coil, and the winding 130 is wound on the iron core 120 to be used as a secondary coil, thereby realizing that the primary current is converted into the secondary current. The number of turns of the winding 130 wound on the core 120 is not limited in the embodiment of the present application, and can be set by a person skilled in the art according to practical situations.

The specific material of the iron core 120 is not limited in this application, and for example, the iron core may be made of silicon steel sheet, and the silicon steel sheet has a silicon iron soft magnetic alloy with very low carbon content, and the silicon content is generally between 0.5% and 4.5%. The resistivity and the maximum magnetic conductivity of the iron can be improved by adding the silicon, the coercive force, the iron core loss (iron loss) and the magnetic aging are reduced, and on the premise of meeting the same performance requirement, the iron core 120 made of the silicon steel sheet material has a smaller volume, so that the volume of the current transformer 100 is reduced, and the development trend of miniaturization and intensification of a switch cabinet is met.

The current transformer 100 provided by the present application includes two oppositely disposed sub-housings 110, the two sub-housings 110 are detachably connected, the sub-housings 110 include a plurality of semi-ring shells 111 having openings, the openings are located between the arms of the semi-ring shells 111, the semi-ring shells 111 have an annular cavity and outlets located at two ends of the annular cavity, the openings of the semi-ring shells 111 face to the same side and are connected in a linear shape along the side walls of the openings, the two oppositely disposed sub-housings 110 are connected to form a plurality of annular shells 112, the number of the annular shells 112 corresponds to the number of cables in the power supply, the cables in the power supply respectively pass through channels formed by the annular shells 112, wherein an iron core 120 and a winding 130 wound on the iron core 120 are respectively disposed in the annular cavity of one of the sub-housings 110, the cables in the power supply serve as a primary coil of the current transformer 100, the winding 130 serves as a secondary coil, and the current value on the primary coil can be obtained by detecting current information on the secondary coil and the ratio of the number of turns of the primary coil and the secondary coil, that is the current value in the power supply cable. When the current transformer 100 provided by the application is installed, only the sub-housings 110 which are arranged oppositely need to be close to each other from the two sides of the power cable respectively, so that the power cable is located behind the channel formed by the annular housing 112, the sub-housings 110 on the two sides are fixedly connected, the power cable does not need to be cut off, and the current transformer 100 is convenient and fast to install.

Optionally, as shown in fig. 3, an insulating material 140 is disposed within the annular cavity to secure the core 120 and the windings 130 to the inner wall of the half-ring shell 111.

The insulating material 140 has good insulation, which can prevent conduction between the components in the annular cavity, and on the other hand, fix the iron core 120 and the winding 130 with the inner wall of the semi-ring shell 111, so as to prevent displacement of the iron core 120 and the coil during transportation or installation.

It should be noted that, in order to show the specific structure in the annular cavity more clearly, fig. 3 is a schematic structural diagram with a part of the housing removed, and in practical applications, the sub-housing covers the iron core 120, the winding 130 and the insulating material 140.

In one enablement of the present embodiment, the insulating material 140 includes an epoxy.

The epoxy resin has excellent insulation, oxidation resistance and plasticity, and is poured between the iron core 120 and the semi-ring shell 111, so that the insulation between the iron core 120 and the outside can be effectively ensured, and the iron core 120 can be well protected.

It should be noted that the insulating material 140 in the current transformer 100 according to the embodiment of the present application is a fixed-shape insulating material 140 formed by pouring the insulating material 140 in a molten state into the annular cavity and curing the insulating material 140. Wherein, the annular cavity is formed by combining two half annular cavities.

In practical applications, the current transformer 100 according to the embodiment of the present application includes:

providing a shell, wherein the shell comprises a plurality of annular shells 112, the plurality of annular shells 112 are connected in a line along the radial direction of the annular shells 112, an annular cavity is formed in the annular shells 112, and the plurality of annular cavities are communicated internally.

The toroidal core 120 is correspondingly disposed in the toroidal cavity, and a half of the toroidal core 120, i.e. the half-ring core, is wound with the winding 130, wherein the plurality of windings 130 are located on the same side of the arrangement direction of the plurality of toroidal shells 112.

And pouring molten epoxy resin into the annular cavity and curing.

The case poured with the epoxy resin is cut such that the ring-shaped case 112 is divided into two half-ring-shaped cases 111, wherein the cutting direction is along the arrangement direction of the ring-shaped cases such that the plurality of half-ring-shaped cases 111 form the sub-case 110.

Alternatively, as shown in fig. 2, connecting portions 150 are respectively disposed at opposite sides of the opening of the half-ring shells 111, and two adjacent half-ring shells 111 are connected by the connecting portions 150.

In order to facilitate the connection of the two sub-housings 110, the connection parts 150 are respectively disposed on two opposite sides of the opening of the half-ring type shell 111, and when the two sub-housings 110 are disposed oppositely, the connection parts connect the two sub-housings 110 at the positions of the connection parts 150, on one hand, the connection parts 150 provide connection points of the connection parts, which facilitates the connection of the two sub-housings 110; on the other hand, the connecting members are provided with connecting points on two opposite sides of the annular shell 112, so that the connection fastness of the sub-shell 110 can be improved. The half-ring shells 111 and the connecting portion 150 in the sub-housing 110 are integrally formed.

In an implementation manner of the embodiment of the present application, as shown in fig. 1, two oppositely disposed sub-housings 110 are detachably connected by a connector, which includes a bolt, a hose clamp or a steel belt.

As can be seen from the above description, the two sub-housings 110 disposed opposite to each other are detachably connected, and specifically, the two sub-housings 110 are detachably connected at the connecting portion 150 by a connecting member, which may be one of a bolt, a hose clamp or a steel belt. When the two sub-housings 110 are connected by the bolts, the connecting members penetrate through the connecting portions 150 corresponding to the two sub-housings 110, so that the two sub-housings 110 are connected; when the hose clamp and the steel belt are connected, the hose clamp and the steel belt are wound around the corresponding connecting parts 150 of the two sub-housings 110 and then fastened. The three modes have the advantages of convenient disassembly and higher connection fastness.

It should be noted that the three connection manners are not specifically limited to the detachable connection, and any connection manner that can satisfy the detachable connection is within the protection scope of the embodiment of the present application.

Optionally, as shown in fig. 1, a plurality of fixing grooves 160 are fixedly disposed on an inner side wall of the ring-shaped shell 112, and an ohmic ring 170 is fixedly disposed on the fixing grooves 160, where the ohmic ring 170 is used for fixing a cable passing through the ring-shaped shell 112.

Each cable in the power supply is used as a primary coil and respectively passes through a channel formed by the annular shell 112, when current flows in each circuit, a magnetic field can be generated due to the law of electromagnetic induction, the annular iron core 120 is arranged in the annular shell 112, the iron core 120 is positioned in the generated magnetic field, and when the cable is positioned at the central position of the annular shell 112, the iron core 120 is positioned at the position where the magnetic field intensity is equal, so that the magnetic eccentricity is prevented from influencing the current conversion effect of the current transformer 100. In order to locate the cable at the center of the ring type case 112, a plurality of fixing grooves 160 are fixedly formed on the inner sidewall of the ring type case 112, ohmic rings 170 are fixedly formed on the fixing grooves 160, and the ohmic rings 170 fix the cable passing through the ring type case 112 such that the cable extends in the axial direction of the ring type case 112. In order to improve the fixing effect of the ohmic coil 170 to the cable, the length of the ohmic coil 170 is set to be the same as the height of the ring-shaped case 112.

The specific number of the ohmic rings 170 and the fixing grooves 160 is not limited in the embodiment of the present application, and may be three, four, five or more.

In an implementation manner of the embodiment of the present application, the plurality of fixing grooves 160 are uniformly distributed on the inner sidewall of the annular shell 112.

When the fixing grooves 160 are uniformly distributed on the inner side wall of the annular shell 112, the circle where the ohmic rings 170 on the fixing grooves 160 are located is concentric with the inner side wall of the annular shell 112, and the supporting force of the ohmic rings 170 on the cable is the same, so that the stress of the cable in the circumferential direction is balanced, and the consistency of the cable position is improved.

Optionally, as shown in fig. 1, a connection terminal is disposed on the half-ring shell 111 provided with the iron core 120 corresponding to the winding 130, or an outlet is disposed on the half-ring shell 111 provided with the iron core 120 corresponding to an inlet and an outlet of the winding 130.

The winding 130 is used as a secondary coil of the current transformer 100, the current value of the current in the cable can be obtained through the current value of the current on the winding 130, in order to obtain the current value of the current on the winding 130, a connection terminal is arranged on the semi-ring shell 111 provided with the iron core 120 corresponding to the winding 130, the connection terminal is provided with two ports corresponding to the winding 130, and the two ports are used for being connected with external measuring equipment to measure the current value of the current in the winding 130. Or, an outlet is formed on the semi-ring shell 111 provided with the iron core 120 corresponding to the inlet and outlet of the winding 130, the inlet and outlet of the winding 130 is exposed through the outlet, and an external measuring device measures the current value of the current in the winding 130 through the inlet and outlet of the winding 130.

A connecting terminal is arranged on the half-ring shell 111 provided with the iron core 120 corresponding to the winding 130, or an outlet is arranged on the half-ring shell 111 provided with the iron core 120 corresponding to an inlet and an outlet of the winding 130, so that the current value of the current in the winding 130 can be conveniently measured, and the current value in the cable can be obtained.

In one implementation of the embodiment of the present application, the ring-shaped shell 112 includes two or three.

In practical applications, the power source in the power distribution system is usually two-phase power or three-phase power, and when the power source is two-phase power, the annular housing 112 includes two power lines, and the two power lines of the two-phase power respectively pass through the two annular housings 112 to measure the current values of the currents in the two power lines. In addition, when the power source is two-phase power, the number of the annular shells 112 may also include three, and two live wires respectively pass through the annular shells 112 at two sides to measure the current value of the current in the two live wires. When the power supply is a three-phase power supply, the ring housing 112 includes three live wires, and cables of the three live wires pass through the three ring housings 112, respectively, to measure current values of currents in the three live wires.

The embodiment of the application also discloses a power distribution system, which comprises a power supply with multi-phase power and the current transformer 100, wherein cables of each phase power of the power supply respectively penetrate through the annular shell 112 of the current transformer 100. The power distribution system includes the same structure and advantages as the current transformer 100 in the foregoing embodiment. The structure and the advantages of the current transformer 100 have been described in detail in the foregoing embodiments, and are not described in detail herein.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (9)

1. The current transformer is characterized by comprising two oppositely arranged sub shells, wherein the two sub shells are detachably connected, each sub shell comprises a plurality of semi-ring shells with openings, the openings are positioned between arms of the semi-ring shells, annular cavities and outlets positioned at two ends of the annular cavities are arranged in the semi-ring shells, the openings of the semi-ring shells face to the same side and are connected in a linear mode along the side walls of the openings, the two oppositely arranged sub shells are connected to form a plurality of annular shells, and an iron core and a winding wound on the iron core are respectively arranged in the annular cavity of one sub shell.

2. The current transformer of claim 1, wherein an insulating material is disposed within the annular cavity to secure the core and the windings to an inner wall of the half-ring type shell.

3. The current transformer according to claim 1, wherein connecting portions are provided on opposite sides of the opening of the half-ring shells, respectively, and adjacent two of the half-ring shells are connected by the connecting portions.

4. The current transformer according to claim 3, wherein the two oppositely disposed sub-housings are detachably connected by a connecting member, and the connecting member comprises a bolt, a hose clamp or a steel band.

5. The current transformer according to claim 1, wherein a plurality of fixing grooves are fixedly formed on an inner side wall of the ring-shaped shell, and ohmic rings for fixing a cable passing through the ring-shaped shell are fixedly formed on the fixing grooves.

6. The current transformer of claim 5, wherein a plurality of fixing slots are uniformly distributed on the inner side wall of the ring-shaped shell.

7. The current transformer according to claim 1, wherein the half-ring shell provided with the iron core is provided with a terminal corresponding to the winding, or the half-ring shell provided with the iron core is provided with an outlet corresponding to an inlet and an outlet of the winding.

8. The current transformer of claim 1, wherein the toroidal shell comprises two or three.

9. An electrical distribution system comprising a power supply having a plurality of phases, and a current transformer according to any one of claims 1 to 8, the cables of each phase of the power supply passing through the toroidal shell of the current transformer.

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