JP2000331847A - Flux controlled electromagnetic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flux controlled electromagnetic apparatus in which opposite laminated iron cores are in the same laminated direction as a laminated electromagnetic steel plate in a pair of cut-core contacts and which comprises an electromagnetic iron core without an insulating film. SOLUTION: Windows 16a and 16b through an iron core are formed on respective legs 11a and 11b in a two or three leg core formed of a laminated iron core. A primary winding 15 connected to an AC power supply and generating primary magnetic flux ϕ1 is wound around the core of each of the legs, and a control winding 14 connected to a control power supply and generating control magnetic flux in a magnetic circuit around the windows is wound around each of the windows. A common circuit of a magnetic circuit for primary magnetic flux due to the primary winding 15 and a magnetic circuit for control magnetic flux due to the control winding 14 is formed on each of windows in the cores, and permeability of the common circuit is adjusted by excited current of the control winding 14 to control the primary magnetic flux ϕ1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic circuit of magnetic flux formed by a main winding and a magnetic circuit of magnetic flux formed by a control winding forming a common magnetic path with each other and controlling the magnetic permeability of the common magnetic path. The present invention relates to a magnetic flux control type electromagnetic device such as a variable reactor and a variable transformer.

[0002]

2. Description of the Related Art For example, Japanese Patent Publication No. 55-64474, Japanese Utility Model Publication No.
A variable reactor described in Japanese Patent Application Laid-Open No. 5534/1993 is known.
The two cut end cores 12 and 13 have a structure in which both leg end faces are in contact with each other by being twisted by 90 degrees.
4 and the magnetic flux φ formed by the winding 15
1 is characterized in that the magnetic circuits passing through are orthogonal, and the magnetic flux of one winding does not interlink with the other winding. Since the magnetic fluxes φ1 and φ2 form a common magnetic path at the contact portion of the pair of iron cores 12 and 13, the DC permeability of the common magnetic path can be adjusted by DC-exciting one of the windings as a control winding. The magnetic flux of the other main winding can be controlled.

[0003] Japanese Patent Publication No. 55-64474 discloses
A saturable reactor used for correcting pincushion distortion of a television screen. Ferrite is used for an iron core because high-frequency current flows, and a spacer for forming a gap is interposed between end faces of the iron core.

Japanese Utility Model Publication No. 8-5534 discloses a variable reactor for compensating for reactive power for electric power. Since a commercial frequency current flows, a laminated core is used, and the end face of the core has a variable control range. It is configured to be as close as possible to increase the size.

[0005]

As described above, when a pair of U-shaped cut cores for electric power formed of a wound iron core are brought into contact with each other so that the cut surfaces are twisted by 90 degrees with respect to the orthogonal magnetic path, Since the laminated end faces of the electromagnetic steel sheets contact each other at right angles to each other, the ends of the laminated electromagnetic steel sheets contact at right angles to each other at the contact surface, and short-circuit the mutually insulated electromagnetic steel sheets. As shown, an eddy current path flowing through the laminated core through the を 通 じ て -shaped contact portion is formed.

[0006] The end faces of the iron core must be as close as possible, but in order to prevent the formation of this eddy current path, they are conventionally brought into contact via an insulating film. For this reason, a gap corresponding to the insulating film is interposed, which inevitably deteriorates the magnetic characteristics, and causes a problem that the variable range of control is reduced.

Further, one of the two cut cores is wound with a control winding which is excited by a direct current, and the other is wound with a main winding which is excited at a commercial frequency. Attraction force is applied, and there is a problem that it is difficult to secure an insulating film having sufficient durability against the continuous vibration stress.

[0008] When a part of the film is damaged and a eddy current path is partially formed by the repetitive stress applied to hit the insulating film at the contact portion of the cut core, heating by the eddy current causes deterioration of the insulating film. Expand further. Due to the deterioration of the insulation film, the eddy current path further expands, and if the damage of the insulation film spreads, a gap will be formed in the contact surface. There was concern that it would expand.

In the case of a high-frequency type in which a ferrite is used for an iron core and a gap forming spacer is interposed, such a problem does not occur. However, the use of ferrite is not suitable for a power electromagnetic device. The problem that the variable control range becomes small arises.

[0010] The present invention has been proposed in view of the above-described situation. In the first and second (the above-mentioned pair of cut cores) core contact portions, the lamination direction of the electromagnetic steel plates of the opposing laminated iron cores is changed. To provide a magnetic flux control type electromagnetic device configured with an electromagnetic core that does not require an insulating film in the same direction,
Further, the present invention provides an electromagnetic iron core that prevents the first and second laminated iron cores from abutting at the end faces and avoiding vibrations hitting the end faces, and further provides harmonics that cause current distortion of the main winding. An object of the present invention is to provide an electromagnetic core that prevents generation of waves.

[0011]

SUMMARY OF THE INVENTION According to the present invention, a window is formed in each leg of a two-legged or three-legged electromagnetic core composed of a laminated core, and a window is formed through the core. Alternatively, a main winding that is connected to a three-phase power supply and generates a main magnetic flux is wound, and a control winding that is connected to a control power supply and generates a control magnetic flux in a magnetic circuit along the periphery of the window is wound around each of the windows. A common magnetic path is formed between the magnetic circuit of the main magnetic flux by the main winding and the magnetic circuit of the control magnetic flux by the control winding in the window of the magnetic core. The main magnetic flux is controlled by adjusting the magnetic susceptibility.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view for explaining an embodiment in which the present invention is applied to a single-phase device.
Numeral 1 denotes an iron core constituting a closed magnetic circuit, and 11a and 11b denote iron cores (magnetic cores) of the two legs. Reference numeral 15 denotes a main winding connected to a single-phase power supply.
occurs in the magnetic circuit passing through b. Magnetic core 11 of both legs of iron core 11
a, 11b, windows 16a, 16b are formed, and cuts 17a, 16y are formed in both side portions 16x, 16y defining the windows.
17b is formed. The control winding 14 is wound through the windows 16a and 16b, and a control magnetic flux φ2 is generated in a magnetic circuit along the periphery of the window. As shown, the magnetic circuits through which the main magnetic flux φ1 and the control magnetic flux φ2 pass are orthogonal to each other, and the main magnetic flux or control magnetic flux generated by both windings does not interlink with the other control winding or main winding.

With the above-described iron core structure, the window forming portions 11m and 11n of the magnetic cores 11a and 11b of the two legs form a common magnetic path for the main magnetic flux φ1 and the control magnetic flux φ2. The main magnetic flux can be controlled by adjusting the magnetic permeability of the magnetic path. With this control, the inductance of the main winding can be controlled, and a variable reactor can be configured. The main winding is used as a primary winding and
If the secondary winding is provided, the voltage of the secondary winding can be controlled, and a variable transformer can be configured. Side 16 that defines the window
The cuts 17a and 17b formed in x and 16y improve the linearity of the change of the magnetic permeability with respect to the magnetic flux of the common magnetic paths 11m and 11n, and reduce the current distortion of the main winding. The closed magnetic circuit core 11 can be formed by winding a band-shaped electromagnetic steel plate, and the electromagnetic core is integrally formed. In addition, the closed magnetic circuit core can be formed by stacking square-shaped punched electromagnetic steel sheets. In this case, the electromagnetic core can be formed integrally. However,
In this case, a part of the control magnetic flux penetrates the steel plate. However, when the control current is DC, there is no problem because it is not necessary to consider the eddy current loss.

FIG. 2 shows the iron core 11 divided into two cut cores 11x and 11y in order to facilitate winding of the winding, and the cut surfaces of the cut cores 11x and 11y are brought into contact with each other, as shown in FIG. It constitutes the iron core 11, in which case,
The lamination direction of the magnetic steel sheets of both cores on the cut surface is made the same direction, eliminating the perpendicular contact of the electromagnetic steel sheets on the contact surface as in the conventional structure, and forming an eddy current flow path flowing through the laminated iron core. It is not to be. FIG.
FIG. 3A is a diagram showing an example of winding of the winding in this case, and FIG. 3A is a perspective view showing a state where the control winding 14 and the main winding 15 are wound around the cut core 11y. FIG. 3 (A)
The configuration when the cut core 11x is brought into contact with the cut core 11y on which the winding is wound as described above.

FIG. 4 shows the cut core 11x or 11y.
First, as shown in FIG. 4A, a long side of a punched electromagnetic steel sheet 11z having a rectangular short piece formed with a recess w corresponding to a window portion is appropriately adjusted as shown in FIG. Then
As shown in FIG. 4 (B), an example is shown in which a pair is formed by bending and then laminating, and they are brought into facing contact with each other. It is clear that the shape of the iron core can be freely set by changing the shape of the punched electromagnetic steel sheet in various ways.

FIG. 5 shows the laminated structure of the electromagnetic steel sheets of the window portion laminated as shown in FIG. 4 (FIG. 5 (A) is a structure before being integrated, and FIG. (A ₂ ) and (b ₂ ) are (a ₁ ) and (b ₂ ), respectively.
FIG. 5 (A) is an enlarged view of the configuration of the contact portion (b ₁ ).
As shown in FIG. 5, the contact portions of the electromagnetic steel sheets are laminated in a comb shape, and the comb-shaped ends of the comb-shaped laminated iron core are overlapped with each other to form a contact portion, as shown in FIG. Configuration.

FIG. 6 illustrates an embodiment for a three-phase device, in which a closed magnetic circuit core 11 includes three cores 11a, 11b, and 11b.
11c. Main magnetic fluxes φ1a, φ1b, φ1c are wound around the magnetic core of the tripod, and the main magnetic fluxes φ1a, φ1b, φ1c are generated in a magnetic circuit passing through the respective magnetic cores. Each magnetic core 11a, 11 of the tripod of the iron core 11
b, 11c through each of the windows 16a, 16b, 1
6c is formed. Control winding 14 through each window
Are wound, and control magnetic fluxes φ2a, φ2b, φ2c are generated in magnetic circuits along the periphery of each window, and the magnetic circuit of the main magnetic flux and the magnetic circuit of the control magnetic flux are orthogonal to each other.

Window portions 11m, 11n, 11 of each magnetic core
o is a common magnetic path of the main magnetic fluxes φ1a, φ1b, φ1c and the control magnetic fluxes φ2a, φ2b, φ2c, respectively. By controlling the exciting current of the control winding, the permeability of the magnetic path can be adjusted to control the main magnetic flux. It is possible to configure a three-phase variable reactor or a three-phase variable transformer. Reference numeral 17 denotes a notch formed in a side portion of the window, which reduces current distortion of the main winding as described above.

It is apparent that the three-phase core can be formed by winding a core, a laminated core, a cut core, and laminating bent steel plates. The orthogonal magnetic path type electromagnetic device is characterized in that since the magnetic flux of the main magnetic flux does not interlink with the control winding, no induced voltage is generated in the control winding, and a voltage due to the main circuit is not applied to the control circuit. Therefore, as shown in FIG. 7, a control winding for forming the control magnetic flux φ2 in a common magnetic path of the magnetic circuit of the main magnetic flux φ1 and the magnetic circuit of the control magnetic flux φ2 is connected to both frame portions 20 of the window provided on the magnetic core, as shown in FIG. , 21 with the same number of turns. In this case, an induced voltage is generated by the main magnetic flux in each of the control windings wound around the two frame portions, but the two windings have the same number of turns, the induced voltages are equal, and the two windings have polarities. Since the connection is reversed, the induced voltage is canceled, and no induced voltage is generated at the terminal of the control winding.

In the above case, the same control as in the case of FIG. 1 can be performed. When the control winding is wound in this manner, a window may be formed in one of the two leg magnetic cores. In the case of a three-phase device as well, control windings for forming control magnetic fluxes φ2a, φ2b, φ2c are wound the same number of times around the window frames 20, 21 of the windows formed on the respective magnetic cores of the tripod core in the same manner as described above. be able to.

In the description of the above embodiment, the number of turns of the control winding of the window frame portion is set to be the same on the assumption that the magnetic paths of both window frames are magnetically symmetric. The point is that the voltage induced in both windings is cancelled, and it is clear that the number of windings differs if the magnetic circuit of the window frame is not magnetically symmetric.

FIG. 8 shows an example of the use of a variable reactor using an electromagnetic core according to the present invention in a power system. A power capacitor C is connected in parallel to a main winding 15 constituting the variable reactor, and By inserting in parallel to the system and controlling the exciting current of the control winding 14, the reactive power from the late phase to the early phase generated in the system is continuously compensated.

FIG. 9 also shows that the capacitor C is connected in parallel to the main winding of each phase of the variable reactor 15 and inserted in series with each phase of the transmission line of the power system, and the exciting current of the control winding is changed. In this example, the impedance of the transmission line is continuously adjusted from the inductive impedance to the capacitive impedance by controlling the power transmission line, and applied to the phase shift control of the receiving voltage or the transmitting voltage in the power system.

FIG. 10 shows that a variable reactor is inserted in a transmission line in series, and when an excessive current of the transmission line is detected, the reactor of the main winding is increased by controlling the exciting current of the control winding to limit the current. The following is an application example of a current limiting reactor.

FIG. 11 shows that a single-phase variable reactor is inserted as an arc-extinguishing reactor into a neutral-point grounding circuit of a transformer connected to a power transmission system, and the phase of the neutral-point voltage and the neutral-point current is changed. This is to detect and control the exciting current of the control winding so that the inductance of the variable reactor is always tuned to the resonance point with the stray capacitance of the system.

FIG. 12 shows an example of application to a starting current suppressing circuit in which a variable reactor is connected in series to an AC power supply circuit of an induction motor. Since the variable reactor is maximum without a control current, the inrush current at startup is suppressed. The control for reducing the variable reactor is started on the condition of the start signal of the induction motor, the variable reactor is reduced to a minimum by a control signal corresponding to the rotation signal, and finally, the terminal of the reactor is short-circuited. It is clear that the same control can be applied to the suppression of the inrush current when the induction generator is connected to the AC type.

FIG. 13 shows an example of application to a circuit in which a variable reactor is connected to a secondary circuit of a wound induction motor and a current is adjusted by a voltage induced in the secondary circuit. , The torque control can be performed from the slip of the induction motor, and the starting current suppression control can be performed by the induction motor starting signal. It is clear that the same control can be applied to the induction generator.

Although the description has been made mainly of the application to the variable reactor, it is apparent that the variable transformer can be formed by winding the secondary winding around the magnetic core around which the main winding is wound. That is what.

[0029]

As described above, in the conventional structure, the interposition of the insulating film for avoiding the formation of the eddy current flow path due to the perpendicular contact of the end faces of the magnetic steel sheet at the contact surface of the cut core is essential. However, the deterioration of magnetic properties due to this is inevitable, and it is extremely difficult at present to secure a durable insulating film. However, according to the present invention, it is possible to form a monolithic iron core by using a laminated iron core. This eliminates the need for an insulating film, avoids deterioration of magnetic properties, and can be used to configure a magnetic flux control type electromagnetic device for electric power that does not cause any trouble due to eddy current.

[0030] Even when the cut core is configured to be in contact, the lamination direction of the electromagnetic steel sheets is the same on the contact surface of the cut core, no eddy current flow path is formed, and the insulating film is interposed. It is not necessary, and it is possible to avoid deterioration of magnetic properties due to the interposition of the insulating film.

As described above, since the present invention does not require an insulating film which was difficult to secure at present,
It can be widely applied as a magnetic flux control type electromagnetic device such as a variable reactor, a variable transformer, and a power coupling device in the electric power field.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an integrated single-phase magnetic flux control type electromagnetic device to which the present invention is applied.

FIG. 2 is an explanatory diagram of an electromagnetic core of the present invention in which the single-phase electromagnetic core shown in FIG. 1 has a cut core configuration.

FIG. 3 is an explanatory diagram of winding winding in the case of a cut core configuration.

FIG. 4 is an explanatory diagram in the case where the electromagnetic iron core of the present invention is formed by laminating stamped steel sheets.

FIG. 5 is an explanatory view of a contact portion of a laminated core.

FIG. 6 is an explanatory diagram of a three-phase magnetic flux control type electromagnetic device to which the present invention is applied.

FIG. 7 is an explanatory diagram of another embodiment of the single-phase magnetic flux control type electromagnetic device of the present invention.

FIG. 8 is a diagram showing an example in which the present invention is applied to a reactive power compensator.

FIG. 9 is a diagram showing an example in which the present invention is applied to a phase shifter.

FIG. 10 is a diagram showing an example in which the present invention is applied to a current limiting device.

FIG. 11 is a diagram showing an example in which the present invention is applied to an arc extinguishing reactor.

FIG. 12 is a diagram showing an example in which the present invention is applied to a starting current suppressing circuit of an induction machine.

FIG. 13 is a diagram showing an example in which the present invention is applied to a speed adjustment, torque adjustment, and starting current suppression circuit of a wound-type induction machine.

FIG. 14 is a diagram illustrating an iron core of a conventional orthogonal magnetic path type electromagnetic device.

FIG. 15 is an explanatory diagram of a conventional iron core.

[Explanation of symbols]

11: iron core (magnetic core), 11a, 11b, 11c: magnetic core leg, 11m, 11n, 11o: magnetic core leg window component, 12, 13: U-shaped cut core, 14: control winding, 1
5, 15a, 15b, 15c ... main winding, 16, 16a,
16b, 16c: windows provided on the legs, 16x, 16y: sides defining the windows, 17, 17a, 17b ... cuts, 2
0, 21: Both frame portions of the window portion.

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[Procedure amendment]

[Submission date] February 17, 2000 (2000.2.1
7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

With the above-described iron core structure, the window forming portions 11m and 11n of the magnetic cores 11a and 11b of the two legs form a common magnetic path for the main magnetic flux φ1 and the control magnetic flux φ2. The main magnetic flux can be controlled by adjusting the magnetic permeability of the magnetic path. With this control, the inductance of the main winding can be controlled, and a variable reactor can be configured. The main winding is used as a primary winding and
If the secondary winding is provided, the voltage of the secondary winding can be controlled, and a variable transformer can be configured. Side 16 that defines the window
The cuts 17a and 17b formed in x and 16y improve the linearity of the change of the magnetic permeability with respect to the magnetic flux of the common magnetic paths 11m and 11n, and reduce the current distortion of the main winding. The closed magnetic circuit core 11 can be formed by winding a band-shaped electromagnetic steel plate, and the electromagnetic core is integrally formed. In addition, the closed magnetic circuit core can be formed by stacking square-shaped punched electromagnetic steel sheets. In this case, the electromagnetic core can be formed integrally .

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Ohinata 7-2-1, Nakayama, Aoba-ku, Aoba-ku, Sendai, Miyagi Prefecture Inside the R & D Center of Tohoku Electric Power Co., Inc. (72) Inventor Shigeaki Akatsuka Nakayama, Aoba-ku, Sendai, Miyagi 1-chome 2-1-1, Tohoku Electric Power Co. R & D Center (72) Inventor Mineo Kawakami 7-2-1, Nakayama, Aoba-ku, Aoba-ku, Sendai City, Miyagi Prefecture F-term (reference) 5E043 BA01

Claims (5)

[Claims] 1. A window penetrating through a magnetic core is formed in each leg of a two-legged or three-legged electromagnetic core composed of a laminated core, and the magnetic core of each leg is connected to a single-phase or three-phase power source. A main winding for generating a magnetic flux is wound, and a control winding for generating a control magnetic flux is wound around a magnetic circuit connected to a control power supply along the periphery of the window in each of the window portions, and a window portion of a magnetic core is provided. A common magnetic path is formed between the magnetic circuit of the main magnetic flux by the main winding and the magnetic circuit of the control magnetic flux by the control winding, and the magnetic flux of the common magnetic path is adjusted by the excitation current of the control winding to control the main magnetic flux. Magnetic flux control type electromagnetic equipment. 2. A magnetic flux control type electromagnetic device according to claim 1, wherein a window is formed in one leg of the two-leg magnetic core. 3. The magnetic flux according to claim 1, wherein the windows formed in each leg of the electromagnetic core so as to penetrate the magnetic core are formed such that the centers of the windows of the respective magnetic cores are substantially coaxial. Controlled electromagnetic devices. 4. A magnetic flux control type electromagnetic device according to claim 1, wherein a wedge-shaped cut is formed in a side portion of the leg defining a window formed in each leg. . 5. The control winding according to claim 1, 2, 3 or 4, wherein the control winding wound around the window formed through the magnetic core comprises a pair of windings wound on each of the opposite frame portions of the window. A magnetic flux control type electromagnetic device characterized by being wound and connected so as to cancel out a voltage induced in both windings by a main magnetic flux.