RU2390865C2 - Current transformer for electric power supply and manufacturing method thereof - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention describes versions of current transformer and their manufacturing methods. Current transformer for electric power supply includes housing having internal space, printed circuit board connected to power supply unit. The first core is made from magnetic material and has loop shape and a gap on one of its sides. Auxiliary core is made from magnetic material and located on one or more sides of the first core so that the above auxiliary core closes the gap. Coil is located around the gap. Therefore, in the area of low current load the supply of electric power can be performed smoothly, and in the area of high current load there prevented is damage to electric power consumer.

EFFECT: enlarging functional capabilities and improving reliability, as well as decreasing dimensions owing to decreasing the number of loops.

19 cl, 14 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a current transformer for power supply and a method for manufacturing it, in particular to a current transformer for a power supply capable of providing smooth current control and to prevent damage to a power consumer, as well as to a method for manufacturing it.

State of the art

Typically, a current transformer for power supply is called a current transformer or a relay current transformer. The current transformer mainly serves as a power source for electrical systems or power supply systems in power distribution equipment, as well as a power source for a trip coil or overcurrent relay in a pneumatic chopper.

As can be seen from FIG. 1 and 2, the current transformer for the power source consists of a loop-shaped core 20, frames 30 interconnected so that a core 20 can fit between them, and the coil winding 40 wound on the frames 30. The primary winding wire 10 is passed inside the coil 20, and the core 20 is formed by laminating from isolated square-shaped annular plates. The frames 30 are connected to each other, being facing each other, so that between them inside the core 20 it was possible to arrange the wire 10 of the primary winding. The coil winding 40 is wound on each of the frames 30.

However, the following problems are inherent in a conventional current transformer for a power source.

Firstly, a saturation phenomenon occurs in the region of a large current, which causes a high voltage at both ends of the coil winding 40 and the passage of a large current. Accordingly, damage can occur in the power consumer, for example in the overcurrent relay.

In order to avoid damage to the power consumer due to the passage of a large current, the power consumer must be additionally equipped with a safety device (or protective circuit).

Moreover, in order to attenuate the current supplied to the coil winding 40, it is necessary to increase the number of turns of the coil winding 40. Therefore, the required size of the coil winding 40 and the number of frames 30 are increased, which leads to an increase in manufacturing cost and an increase in the dimensions of the entire current transformer for the power source.

Disclosure of invention

The present invention is a current transformer for a power source, capable of providing smooth regulation of the current and prevent damage to the consumer of electricity, as well as a method for its manufacture.

The next objective of the present invention is a current transformer for a power source, capable of providing smooth control of the power supply at low current strength and prevent voltage increase above a predetermined level at high current strength, as well as a method for its manufacture.

Another objective of the present invention is a current transformer for a power source, characterized by a reduced number of turns of the coil of the coil and reduced own dimensions, as well as a method for its manufacture.

To achieve these and other advantages, as well as in accordance with the purpose of the present invention, the embodiments and detailed description of which are given in this application, a current transformer for a power supply is provided, comprising: a first core formed of magnetic material having a loop shape and a gap one of its parties; and an auxiliary core formed of magnetic material located on one or more sides of the first core so that said auxiliary core closes the gap.

The first core may include a straight section, and a gap can be made on said straight section.

The first core may include segmented cores, each of which has a straight section and a rounded section, which is a continuation of a straight section from one of the ends of the said straight section.

The auxiliary core may include a straight portion corresponding to a straight portion of the first core and a rounded portion having a greater length than one of the rounded portions of the segmented cores.

The auxiliary core may be located on both sides of the first core in the thickness direction.

The auxiliary core may be positioned so that one of its rounded sections may be in contact with two rounded sections of the segmented cores.

The current transformer for the power source may further comprise a coil winding located around the gap.

A further object of the present invention relates to a current transformer for a power source, comprising: a first core formed of magnetic material having a loop shape and a gap on one of its sides; and a second core formed of magnetic material having a shape corresponding to the first core and located on one or more sides of the first core.

The first core may include a rectilinear portion, and a gap may be formed on the rectilinear portion.

The current transformer for the power source may further comprise a coil winding located around the gap.

The first core may include segmented cores, each of which has a straight section and a rounded section, which is a continuation of a straight section from one of the ends of the said straight section.

The second core may include a straight portion and a rounded portion corresponding to a straight portion and a rounded portion of the first core.

The current transformer for the power source may further comprise an auxiliary core having a shape corresponding to the shape of the first core or second core, and located on one or more sides of the first core or second core.

The auxiliary core may include a straight portion corresponding to a straight portion of the first core and a rounded portion having a greater length than one of the rounded portions of the segmented cores.

The auxiliary core may be located on both outer sides of the first core and the second core in the thickness direction.

The auxiliary core may be positioned so that one of its rounded sections may be in contact with two rounded sections of the segmented cores.

To achieve these and other advantages, as well as in accordance with the purpose of the present invention, embodiments and a detailed description of which are given in this application, there is also a method of manufacturing a current transformer for a power source, comprising the steps of: forming a core having a loop shape and a gap in one of its sections; and wrap the coil winding around the gap.

The step of forming the core may comprise the step of forming segmented cores located opposite each other so that a gap is formed between them. The core forming step may further comprise the step of arranging an auxiliary core made of magnetic material on one or more sides of the segmented cores so as to close the gap.

Before arranging the second core, the core forming step may further comprise the step of forming the second core by forming segmented cores located opposite each other and forming a closed loop.

The method may further comprise the step of arranging the auxiliary core on the outside of the second core.

The method may further comprise creating a framework before forming the core. At the stage of core formation, segmented cores can be inserted into the frame so that a gap is formed.

The method may further comprise the step of positioning the frame around the gap before winding the coil winding.

All the above and other objectives, features, objects and advantages of the present invention will be more apparent from the following detailed description of the present invention when considered together with the accompanying drawings.

Brief Description of the Drawings

The accompanying drawings, included in the application materials to provide a more complete understanding of the invention and forming part of the present description, illustrate embodiments of the invention and together with the description serve to explain the principles of the present invention.

In the drawings:

Figure 1 is a view in section of a current transformer for a power source according to the prior art.

FIG. 2 is a side view of a current transformer for the power supply shown in FIG. 1.

FIG. 3 is a perspective view of a current transformer for a power supply according to a first embodiment of the present invention in an exploded state.

FIG. 4 is a plan view showing a current transformer for a power supply shown in FIG. 3 in an assembled state.

FIG. 5 is a bottom view of the image of FIG. 4.

FIG. 6 is a front view of the power source shown in FIG. 3.

FIG. 7 is a perspective view of the core shown in FIG. 6.

FIG. 8 is a front view of the first core of FIG. 7.

FIG. 9 is a front view of the sub core shown in FIG. 7.

FIG. 10 is a perspective view of a current transformer core for a power supply according to a second embodiment of the present invention.

FIG. 11 is a front view of the second core of FIG. 10.

FIG. 12 is a view showing an exemplary embodiment of a process for connecting a core to a current transformer frame for a power supply according to a first embodiment of the present invention.

FIG. 13 is a view showing another exemplary embodiment of a process for connecting a core to a current transformer frame for a power supply according to a first embodiment of the present invention.

FIG. 14 is a view showing a relationship between a primary current and a secondary current of a current transformer for a power supply of the present invention.

The implementation of the invention

Next will be described in detail preferred embodiments of the present invention, examples of which are shown in the accompanying drawings.

This section provides a more detailed description of the current transformer for the power source and its manufacturing method.

As shown in FIG. 3-5, a current transformer for power supply comprises a housing 120 with an internal space, a power supply unit 140 for supplying a current induced by the primary winding wire 110 to a power consumer, such as a maximum current relay, a current measuring element 181 for measuring the current flowing through the wire 110 primary winding, a printed circuit board 191 connected to a power unit 140 and a current measuring element 181.

The connecting portion 122 of the primary winding wire for connecting the primary winding wire 110 is formed on the housing 120. The current measuring element 181, made in the form of a Rogowski circular belt, is located around the connecting portion 122 of the primary winding wire. An insulating element 185 is located on one side (the upper side in FIG. 3) of the current measuring element 181. The printed circuit board 191 is rigidly fixed by a screw 193 between the current measuring element 181 and the power supply unit 140. The connector 135 is formed on one of the sections of the housing 120 so that it is electrically connected to the printed circuit board 191 and the consumer of electricity.

As shown in FIG. 6, the power unit 140 includes a core 141 located around the primary winding wire 110, a frame 171 connected to the core 141, and a coil winding 175 wound on the frame 171. The coil winding 175 is housed in a housing 120 that is open on one side. The cover 130 is connected to the housing 120 by a screw 133, thereby closing the coil winding 175.

As shown in FIG. 7, the core 141 includes a first core 151 made of magnetic material and having a loop shape with a gap (G) on one of its sides; and auxiliary cores 161 formed of thin plate-shaped magnetic material and located on one or more sides of the first core 151 so that they close the gap (G). The number of plates of the first core 151 and the thickness of each of the auxiliary cores 161 are set in accordance with their capacity in relation to the rated current.

As shown in FIG. 8, the first core 151 is formed as a pair of segmented cores 155 located opposite each other so that a gap (G) is formed between them. The segment cores 155 of the first core 151 are formed by batching the insulated plates, each plate having a straight portion 156 and a rounded portion 157 formed by rounding at one end of the straight portion 156. The straight portion 156 of the segment core 155 is formed so that it is removed from the center line (C _L ) of the first core 151 at a specific distance (G / 2). Accordingly, if two segmented cores 155 are arranged symmetrically to each other on the center line (C _L ) so that the ends of the two rounded sections 157 are in contact with each other, a gap (G) is formed between the two straight sections 156.

The auxiliary cores 161 have a shape corresponding to the first core 151 and include straight sections 163 and rounded sections 165 formed by rounding at one end of each straight section 163. As shown in FIG. 7, the straight sections 163 of the auxiliary cores 161 are formed so that they extend over the entire length of the straight sections 156 of the first core 151, including the gap (G). In FIG. 9 shows that the rounded sections 165 of the auxiliary cores 161 are formed so that they are longer than the rounded sections 157 of the segment cores 155 of the first core 151, protruding beyond the center line (C _L ). That is, the rounded sections 165 of the auxiliary cores 161 are formed so that they are long enough to close the mating area between the two ends of the two rounded sections 157 of the two segment cores 155 of the first core 151. The auxiliary cores 161 are arranged so that their two rounded section 165 are in contact with two rounded sections 157 of two segmented cores 155 of the first core 151.

With this configuration, the straight section 156 of the first core 151 is inserted into the frame 171, and the auxiliary cores 161 are placed on both sides of the first core 151. Then, the two ends of the straight sections 156 of the first core 151 and the two rounded sections 157 are connected to each other in the area of their contact by argon welding etc.

When current flows through the primary wire 110, magnetic flux is induced in the core 141, and a secondary current is generated in the coil winding 175. Secondary current is supplied to a power consumer, for example, an overcurrent relay, connected by a printed circuit board 191 to a connector 135.

Next, an explanation will be given to a current transformer for a power supply according to a second embodiment of the present invention with reference to FIG. 10 and 11. For convenience of explanation, the configuration and components similar to those presented with respect to the first embodiment of the invention are denoted by the same reference numerals. As shown in FIG. 10, the core 211 consists of a first core 151 formed of magnetic material and having a loop shape and a gap (G) on one of its sides, and a second core 221 formed of magnetic material and having a shape corresponding to the shape of the first core 151, and located on one or more sides of the first core 151. As already mentioned, the first core 151 has two segmented cores 155. The first core 151 and the second core 221, respectively, are formed by batching insulated thin plates and of magnetic material, and the number of plates can be selected in accordance with their capacity in relation to the rated current.

The second core 221 consists of one pair of segmented cores 225, symmetrical to each other. Segment cores 225 of the second core are formed by batching insulated thin plates of magnetic material, with each magnetic plate having a straight portion 226 and a rounded portion 227 curved from one end of the straight portion 226.

One pair of auxiliary cores 161 is connected to each of the outer loops of the first core 151 and the second core 221. Each of the auxiliary cores 161 is formed of magnetic material and includes a straight portion 163 and a rounded portion 165. Two rounded sections 165 of the auxiliary cores 161 are contacted with the rounded sections 157, 227 of the first and second cores 151, 221. In this case, the auxiliary cores 161 can be formed from non-magnetic materials.

With this configuration, the straight sections 156, 226, 163 of the first core 151, the second core 221 and the auxiliary cores 161 are inserted into the frame 171. Then, the auxiliary cores 161, the two ends of the straight sections 156 of the first core 151 and two rounded sections are welded to each other. 157, thereby integrating the first core 151, the second core 221 and the auxiliary cores 161.

Next, an explanation will be given of an exemplary embodiment of a current transformer for a power supply according to a second embodiment of the present invention with reference to FIG. 12.

As shown in FIG. 12, the current transformer for the power source comprises a first core 255 formed of magnetic material and having a loop-like shape and a gap on one of its sides; and an auxiliary core 261 formed of magnetic material and connected to the first core 255 so that it closes the gap (G) of the first core 255 on one or more sides.

The first core 255 includes one U-shaped rounded portion 257; and two straight sections 256 linearly curved at both ends of the rounded section 257, and a predetermined air gap (G) between them. The first core 255 is formed by batching insulated thin plates.

The auxiliary core 261 is linearly formed so that it has a length corresponding to two straight sections 256 of the first core 255. In this way, the length of the auxiliary core 261 can be determined.

The frame 271 is connected to the straight sections 256 of the first core 255 so that it can be wound around the coil of the coil. The frame 271 consists of a first element 273 and a second element 275, interconnected face to each other in the thickness direction. Guide sections 274, 276 are formed at both ends of the first and second elements 273, 275, respectively, so that they protrude in width and beyond the girth of the respective elements.

With this configuration, the first and second elements 273, 275 are connected to each other so that straight sections 256 of the first core 255 can be placed between them. Then, the coil winding is wound on the first and second elements 273, 275 connected to each other.

Next, explanation will be given to another exemplary embodiment of a current transformer for a power supply according to a first embodiment of the present invention with reference to FIG. 13.

As shown in FIG. 13, the current transformer for the power source comprises a first core 255 formed of magnetic material and having a loop shape and a gap on one of its sides; and a second core 281 formed of magnetic material having a shape corresponding to the shape of the first core 255 and located on one or more sides of the first core 255.

The first core 255 includes a U-shaped rounded portion 257; and straight sections 256 linearly curved at both ends of the rounded section 257 with a predetermined gap (G) between them.

The second core 281 is formed so that it has a closed loop shape that includes straight sections 283 corresponding to straight sections 256 of the first core 255, and rounded sections 285 connecting the two ends of the straight sections 283. The second core 281 is located on both sides of the first core 255 in the direction of thickness. In this case, the second core 281 may be located on one side of the first core 255.

The frame 271 is connected to the straight sections 256, 283 of the first and second cores 255, 281 so that they can wrap the coil of the coil. The frame 271 consists of a first element 273 and a second element 275 connected to each other by their face to each other so that straight sections 256, 283 can be placed between them.

With this configuration, the first and second cores 255, 281 are welded to each other, and the first and second elements 273, 275 are connected with their faces to each other so that straight sections 256, 283 of the first cores 255, 281 fit between them. the first and second elements 273, 275 connected to each other, wrap the coil of the coil.

Next, with reference to FIG. 14, the relationship between the primary current and the secondary current of the current transformer for the power supply according to the present invention will be explained.

As shown in FIG. 14, curve L1 indicates that in a conventional current transformer for a power source, the secondary current increases linearly as the primary current rises in the low current zone. With increasing primary current, the saturation phenomenon easily arises. In this case, if the saturation phenomenon occurs in the zone of high current strength, the rms value does not increase, but the peak value of the current increases. As a result, damage to the consumer can occur, such as overcurrent relays.

As shown in FIG. 14, curve L2 indicates that in the current transformer for the power supply according to the first embodiment of the present invention, the secondary current non-linearly increases in proportion to the primary current. When a small current flows through the primary winding wire 110, a secondary low current can be stably supplied to the power consumer. With increasing primary current, the secondary current increases nonlinearly. If a large current, such as an emergency current, flows through the primary winding wire 110, the magnetic flux is limited due to the presence of a core gap (G), thereby reducing the secondary current. Accordingly, in this way, damage to the power supply, for example the overcurrent relay, due to the arrival of a large current, can be prevented.

As shown in FIG. 14, curve L3 indicates that in the current transformer for the power supply according to the second embodiment of the present invention, the secondary current rises in proportion to the primary current. The secondary current according to the second embodiment of the invention is weaker than the secondary current in a conventional transformer, but stronger than the current according to the first embodiment of the invention because the gap (G) is smaller than the gap (G) according to the first embodiment of the invention.

As shown in FIG. 14, curve L4 indicates that by increasing the size of the gap (G) according to the first embodiment of the invention, a secondary current of small force can be provided, and the time required to achieve saturation increases.

As indicated above, in the current transformer for the power source and according to the manufacturing method of the present invention, a gap is formed in the core to limit the magnetic flux, thereby reducing the secondary current, thereby preventing damage to the power source, for example, an overcurrent relay, due to the large current supply strength.

Moreover, in the current transformer for the power source and according to the manufacturing method of the present invention, the number of coil windings can be reduced by limiting the magnetic flux induced in the core, the manufacturing cost can be reduced by reducing the number of frames, and the overall dimensions of the current transformer can be reduced. .

In addition, in a current transformer for a power source in the low current zone, the consumer is supplied with power stably, and in the high current zone the magnetic flux induced in the core is properly controlled. In this way, damage to the power supply due to the supply of high current can be prevented.

The above described embodiments and advantages are merely examples and should not be construed as limiting the scope of the present invention. The data of the present description can easily be applied to other types of devices. The description is illustrative and does not limit the scope of the claimed invention. Numerous alternatives, modifications, and variations will be apparent to those skilled in the art. Signs, designs, methods and other characteristics of exemplary embodiments of the present invention described herein can be used in various combinations to obtain additional and / or alternative exemplary embodiments of the invention.

Since the features described in this application can be implemented in several ways without violating the specified characteristics, it should be understood that the above embodiments of the invention are not limited to any details of the above description, unless otherwise indicated, and should be construed in a broad sense within the scope of the present invention defined by the appended claims, and therefore all changes and modifications made within the scope and scope of the claims or and equivalent conditions are considered to be included in the scope of the attached claims.

Claims (19)

1. A current transformer for a power source, comprising:
a housing having an internal space;
a power supply unit for supplying a current induced by the primary winding wire to a power consumer; and
a printed circuit board (PCB) connected to a power supply,
moreover, the power supply contains:
a first core formed of magnetic material and having a loop-like shape and a gap on one of its sides;
an auxiliary core formed of magnetic material and located on one or more sides of the first core so that said auxiliary core closes said gap; and
a coil located around the gap. 2. The current transformer for the power source according to claim 1, in which the first core contains a straight section, and a gap is formed on said straight section. 3. The current transformer for the power supply according to claim 2, in which the first core contains segment cores, each of which has a straight section and a rounded section, which is a continuation of a straight section from one of the ends of the said straight section. 4. The current transformer for the power source according to claim 3, in which the auxiliary core contains:
a straight section corresponding to a straight section of the first core; and
a rounded section that is longer than one of the rounded sections of the segmented cores. 5. The current transformer for the power supply according to claim 4, in which the auxiliary core is located on both sides of the first core in the thickness direction. 6. The current transformer for the power source according to claim 5, in which the auxiliary core is located so that one of its rounded section can be in contact with two rounded sections of the segment cores. 7. A current transformer for a power source, comprising:
a housing having an internal space;
a power supply unit for supplying a current induced by the primary winding wire to a power consumer; and
a printed circuit board (PCB) connected to a power supply,
moreover, the power supply contains:
a first core formed of magnetic material and having a loop-like shape and a gap on one of its sides;
a second core formed of magnetic material having a shape corresponding to the first core and located on one or more sides of the first core; and
a coil located around the gap. 8. The current transformer for the power supply according to claim 7, in which the first core contains a straight section, and the gap is formed on a straight section. 9. The current transformer for the power source according to claim 7, in which the first core contains:
segmented cores, each of which has a straight section and a rounded section, which is a continuation of the straight section from one of the ends of the said straight section, and
in which the second core contains a straight section and a rounded section corresponding to a straight section and a rounded section of the first core. 10. The current transformer for the power source according to claim 9, further comprising an auxiliary core having a shape corresponding to the first core or second core, and located on one or more sides of the first core or second core. 11. The current transformer for the power source of claim 10, in which the auxiliary core contains:
a straight section corresponding to a straight section of the first core, and
a rounded section that is longer than one of the rounded sections of the segmented cores. 12. The current transformer for the power supply according to claim 11, in which the auxiliary core is located on both outer sides of the first core and the second core in the thickness direction. 13. The current transformer for the power supply according to item 12, in which the auxiliary core is located so that one of its rounded section can be in contact with two rounded sections of the segment cores. 14. A method of manufacturing a current transformer for a power source, comprising the steps of:
form a core having a loop-like shape and a gap in one of its sections; and
wrap the coil around the gap
moreover, the stage of core formation comprises a stage at which segmented cores are formed, facing each other so that a gap is formed between them,
moreover, the step of forming the core further comprises the step of placing an auxiliary core formed of magnetic material on one or more sides of the segmented cores so that said auxiliary core closes the gap. 15. The method according to 14, further comprising a stage, before which the core is provided with a frame, and at the stage of forming the core, segmented cores are inserted into the frame so that a gap is formed in the frame. 16. The method according to 14, further comprising the step of placing a frame around the gap before winding the coil. 17. A method of manufacturing a current transformer for a power source, comprising the steps of:
form a core having a loop-like shape and a gap in one of its sections; and
wrap the coil around the gap
moreover, the stage of core formation comprises a stage at which segmented cores are formed, facing each other so that a gap is formed between them,
moreover, the step of forming the core comprises a step in which a second core formed of magnetic material and having a loop-like shape is disposed on one or more sides of the segmented cores so that said second core closes the gap. 18. The method according to 17, which, before the step of arranging the second core, further comprises the step of: forming a second core by forming segmented cores arranged face to face and forming a closed loop. 19. The method according to p. 18, further containing a stage in which the auxiliary core is located on the outside of the second core.

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