JP2013042028A - Three-phase electromagnetic device - Google Patents

Abstract

The present invention relates to a three-phase electromagnetic device that is excellent in three-phase balance capable of varying reactance and is easy to assemble with low distortion.
Eighteen linear magnetic cores are arranged radially symmetrically, and each central end and each peripheral end of the linear magnetic core are connected by a connecting magnetic core to form an 18-leg magnetic core. An AC main winding is wound around the linear magnetic core every two legs, a DC control winding is wound around the other linear magnetic core, and two AC main windings are symmetrically paired to form a three-phase AC winding. AC main winding for each phase. Each DC control winding is connected so that the electromotive force induced in each DC control winding is canceled by the main magnetic flux of the three-phase AC main winding. A direct current control current is supplied to the direct current control winding to generate a direct current control magnetic flux, and the magnetic resistance of the common magnetic path of the main magnetic flux and the control magnetic flux is controlled to continuously vary the reactance of the alternating current main winding.
[Selection] Figure 1

Description

  The present invention relates to an electromagnetic device capable of varying a three-phase reactance. In particular, the present invention relates to a three-phase electromagnetic device having excellent three-phase balance with a wide variable range of reactance, which has less harmonic distortion and does not require a gap on the abutting surface of an iron core.

  Conventional techniques that can vary reactance include a three-phase electromagnetic device (Patent Document 1) and a three-phase electromagnetic device (Patent Document 2) previously proposed by the present applicant.

  FIG. 11 is a connection diagram for explaining an example of a three-phase electromagnetic device previously proposed by the present applicant. This three-phase electromagnetic device includes three H-shaped leg portions 44a to 44c that form a magnetic path with each end paired, and two frames that form a closed magnetic circuit by connecting the end sides of these H-shaped leg portions. The main windings 41aa to 41cb corresponding to the respective phases of the three-phase AC power source are wound around each magnetic path on one coupling end side of the H-shaped leg portion. Control windings 42aa to 42cb are wound around each magnetic path on the other connection end side. The main winding is connected in series or in parallel so that the main magnetic flux generated in the pair of magnetic paths is in the same direction, and the control winding is connected in series so that the induced voltages generated by the main magnetic flux are canceled each other. The reactance of the main winding is continuously varied by controlling the magnetic resistance of the common magnetic path of the main magnetic flux and the control magnetic flux.

  FIG. 12 is a connection diagram for explaining an example of the three-phase electromagnetic device previously proposed by the present applicant. In this three-phase electromagnetic device, six linear magnetic cores 53aa to 53cb are arranged so that an angle with an adjacent linear magnetic core is 60 °, and six iron core window portions are formed at one end of the six linear magnetic cores. As shown in FIG.

Three pairs of main windings 51aa to 51cb are wound around the six linear magnetic cores 53aa to 53cb, and are connected in series or in parallel so that the magnetic flux generated from each pair of main windings is in the same direction.
Control windings 52a to 52f are wound around the six connecting magnetic cores 53d connected to the linear magnetic cores, respectively, so that induced voltages generated in the control windings 52a to 52f are canceled by the magnetic fluxes of the main windings. The control windings are connected in series or in parallel to control the magnetic resistance of the common magnetic path of the main magnetic flux and the control magnetic flux to continuously vary the reactance of the main winding.

Japanese Patent No. 3986809 Japanese Patent No. 4646327

  However, the three-phase electromagnetic device of Patent Document 1 can control the magnetic resistance of the common magnetic path of the main magnetic flux and the control magnetic flux and continuously vary the reactance of the main winding, but the reactance can be varied. The range was narrow, and there was a tendency for imbalance between the three phases to occur during reactance control.

  The reason is that the adjustment range of the magnetic resistance of the common magnetic path of the main magnetic flux and the control magnetic flux is narrow, the magnetic resistance of the main magnetic path by the main winding wound around the control central leg and the outer leg is wound around It was thought that the magnetic resistance of the main magnetic path by the main winding was different.

  In addition, the three-phase electromagnetic device disclosed in Patent Document 2 can control the magnetic resistance of the common magnetic path of the main magnetic flux and the control magnetic flux and continuously vary the reactance of the main winding. Since three main windings or control windings are wound around the window, the space factor of the windings is lowered.

  Since it is necessary to wind the control winding around the connecting magnetic core, manual winding is required after the magnetic core is configured.

  Furthermore, the common magnetic path of the main magnetic flux and the control magnetic flux for varying the reactance is mainly the magnetic path around the window around which the control winding is wound, and since the adjustment range of the magnetic resistance is narrow, the variable range of the reactance is also Not wide.

  Therefore, in view of the above problems, the present invention has no unbalance between the three phases, does not require a gap in the abutting surface of the iron core, has a wide variable range of reactance, and has a simple winding structure for winding. An object of the present invention is to provide a three-phase electromagnetic device capable of changing the reactance of a simple three-phase integrated structure.

The present invention achieves the above object by the following technical means.
Eighteen linear magnetic cores are arranged radially symmetrically, and each central end and each peripheral end of the linear magnetic core are connected by a connecting magnetic core to form an 18-leg magnetic core, and two legs are placed on the linear magnetic core. An AC main winding is wound around the DC core, a DC control winding is wound around the linear magnetic core located between the linear magnetic cores wound with the AC main winding, and the two AC main windings are symmetrical. Each DC control winding is configured such that the three-phase AC main winding is paired with the three-phase AC main winding and the electromotive force induced in each DC control winding is canceled by the three-phase AC current of the three-phase AC main winding. Are connected in series or in series and parallel, a DC control current is supplied to the DC control windings connected in series to generate a control magnetic flux, and a main magnetic flux generated by the current of the AC main winding and a common magnetic path of the control magnetic flux Featuring a three-phase electromagnetic device that controls the magnetic resistance and continuously varies the reactance of the AC main winding That

  The AC main windings of each phase that are symmetrically paired are two adjacent AC main windings.

  The AC main windings of each phase that are symmetrically paired are two AC main windings arranged in a substantially straight line.

  Furthermore, the direction of the AC main magnetic flux generated in the two linear magnetic cores by the AC main windings of the respective phases that are symmetrically paired is opposite to the central direction of the linear magnetic core.

  Furthermore, the direction of the AC main magnetic flux generated in the two linear magnetic cores by the AC main windings of the respective phases that are symmetrically paired is the same as the direction of the center of the linear magnetic core.

  Furthermore, a secondary winding is wound around a linear magnetic core wound with an AC main winding of each phase, and a transformer function is provided.

  According to the present invention, there is no need to provide a tap, no gap is required in the abutting surface of the iron core, a low cost can be expected with a simple assembly structure, and a three-phase balance excellent in three-phase balance that can vary reactance over a wide range. A phase electromagnetic device can be realized.

  By using the present invention in a power system, it is possible to provide flexible power equipment that can cope with fluctuations in the voltage of the power system, etc., due to the recent increase in power demand and diversification of loads. Can contribute to more appropriate control of power generation and power factor.

It is a figure which shows the structural example of the three-phase electromagnetic device by this invention. It is a figure which shows the equivalent circuit of the three-phase electromagnetic device of this invention. It is a figure for demonstrating the structural example of the three-phase electromagnetic device by this invention. It is a figure which shows the example of a magnetic core structure of the three-phase electromagnetic device by this invention. It is a figure which shows the example of a magnetic core assembly of the three-phase electromagnetic device by this invention. It is a figure which shows the other structural example of the three-phase electromagnetic device by this invention. It is a figure which shows the further another structural example of the three-phase electromagnetic device by this invention. It is a figure which shows the control characteristic example of the three-phase electromagnetic equipment of this invention. It is a figure which shows the example of the three-phase electromagnetic device which has a transformation function by this invention. It is a figure which shows the example of application to the reactive power compensation apparatus of this invention. It is a figure which shows the example of the conventional three-phase electromagnetic device. It is a figure which shows the other example of the conventional three-phase electromagnetic device.

  FIG. 1 is a connection diagram showing a basic configuration example of a magnetic core and windings of a three-phase electromagnetic device according to the present invention, and FIG. 2 is a diagram showing a circuit configuration equivalently displaying a circuit of the three-phase electromagnetic device of the present invention. 3 is a diagram for explaining a configuration example of the three-phase electromagnetic device shown in FIG. The basic configuration of the present invention will be described below.

  As shown in FIG. 3, the magnetic cores constituting the three-phase electromagnetic device are 18 linear magnetic cores 3aa, 3ab, 3ba, 3bb, 3ca, 3cb, 3da, 3db, 3dc, 3dd, 3de, 3df, 3dh, 3dh, 3di. 3dj, 3dk, and 3dL are arranged radially so that the angle between adjacent linear magnetic cores is approximately 20 °. Further, the center side (inner side) end portion and the peripheral side (outer side) end portion of the 18 linear magnetic cores are connected by connecting magnetic cores 3e and 3f so that 18 iron core window portions are formed. In addition, 18 linear magnetic cores 3aa, 3ab, 3ba, 3bb, 3ca, 3cb, 3da, 3db, 3dc, 3dd, 3de, 3df, 3dg, 3dh, 3di, 3dj, 3dk and 3dL, and the connecting magnetic cores 3e and 3f Since the joining portion is not a magnetic gap, each laminated steel plate constituting the magnetic core is abutted so as to be parallel, or the end portions of the laminated steel plates are engaged to be connected.

  Among the 18 linear magnetic cores, AC main windings (hereinafter referred to as main windings) are wound around six linear magnetic cores 3aa, 3ab, 3ba, 3bb, 3ca and 3cb having an angle of the linear magnetic core of approximately 60 °. Disguise.

  The main winding 1aa is wound around the first linear magnetic core 3aa, and the main winding 1ab is wound around the second linear magnetic core 3ab arranged on the same axis as the linear magnetic core 3aa. The main windings 1aa and 1ab are connected in series or in parallel so that the magnetic fluxes φa1 and φa2 generated from both main windings are in the same direction.

  Similarly, the main winding 1ba is wound around the third linear magnetic core 3ba, and the main winding 1bb is wound around the fourth linear magnetic core 3bb arranged on the same axis as the linear magnetic core 3ba, so that the fifth linear magnetic core is wound. The main winding 1ca is wound around 3ca, and the main winding 1cb is wound around the sixth linear magnetic core 3cb arranged on the same axis as the linear magnetic core 3ca.

  The main windings 1ba and 1bb and the main windings 1ca and 1cb are connected in series or in parallel so that the magnetic fluxes φb1 and φb2 and the magnetic fluxes φc1 and φc2 generated from both main windings are in the same direction.

  12 linear magnetic cores 3da, 3db, 3dc, 3dd, 3de, 3df, 3dg, 3dh, 3di, 3dj, 3dk, and 3dL other than the linear magnetic core around which the main winding is wound are each provided with a DC control winding ( Hereinafter referred to as a control winding.) 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k, and 2L are wound. Control windings 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2j, 2k, and main windings 1aa and 1ab, main windings 1ba and 1bb, and magnetic fluxes from the main windings 1ca and 1cb The control windings are connected in series or series-parallel so that the induced voltages generated at 2L are canceled out, and the control circuit 4 is connected to the open terminal side.

  In each control winding, an induced voltage is generated by the main magnetic flux generated by the main current of each of the three phases flowing in the main winding, but the induced voltage corresponding to the main magnetic flux of each of the three phases is controlled by the corresponding control. It is canceled out by connecting the windings in series.

  Therefore, in the figure, it is possible to connect all the control windings in series, or symmetrically connect the control windings in half and connect them in series and parallel.

  In the figure, it is assumed that a three-phase AC power source is connected to an open terminal of a main winding that is wound and connected to a linear magnetic core, and currents ILu, ILv, and ILw in the directions indicated by the arrows flow through the respective main windings. When the current arrow direction shown in the figure is a positive cycle, a current in the reverse direction flows in the negative cycle.

  In the three-phase electromagnetic device having the above-described configuration, the AC magnetic flux of each phase generated from the main windings 1aa and 1ab, the main windings 1ba and 1bb, and the main windings 1ca and 1cb passes through the connecting magnetic core portion connecting the linear magnetic cores. Reflux.

  Hereinafter, description will be made by paying attention to the first linear magnetic core portion 3aa around which the main winding 1aa is wound and the second linear magnetic core portion 3ab around which the main winding 1ab is wound.

  When current ILu flows, main magnetic flux φa1 and main magnetic flux φa2 are generated in the magnetic path by main winding 1aa and main winding 1ab, respectively.

  The generated main magnetic flux φa1 passes through the linear magnetic core portions 3da and 3dL around which the control winding is wound, and reactance according to the number of turns and the magnetic resistance of the magnetic core is generated in the main winding 1aa.

  Similarly, the main magnetic flux φa2 passes through the linear magnetic core portions 3dg and 3df, and reactance corresponding to the number of turns and the magnetic resistance of the magnetic core is generated in the main winding 1ab.

  Here, the linear magnetic cores 3da and 3dL around which the control winding is wound serve as a common magnetic path for the control magnetic flux φdc and the main magnetic flux φa1. Similarly, the linear magnetic core portions 3dg and 3df serve as a common magnetic path for the control magnetic flux φdc and the main magnetic flux φa2.

  As described above, the linear magnetic core portion 3ba around which the main winding 1ba is wound, the linear magnetic core portion 3bb around which the main winding 1bb is wound, the linear magnetic core portion 3ca around which the main winding 1ca is wound, and the main winding 1cb. The same applies to the case where attention is paid to the wound linear magnetic core portion 3cb. That is, the linear magnetic cores adjacent to both sides of the linear magnetic core portion around which the main winding is wound are respectively shared by the control magnetic flux φdc and the main magnetic fluxes (φa1, φa2, φb1, φb2, φc1, φc2) generated by the main winding. It becomes a road.

  When a DC control current Ic is passed through the control winding in a state where the main winding current ILu is passed, in the control windings 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k and 2L, By generating a magnetomotive force represented by the product of the number of turns of the control winding and the control current Ic, the magnetic flux density in the common magnetic path portion where the control winding magnetic flux φdc and the main magnetic fluxes φa1 and φa2 are in the same direction increases. As a result, the magnetic permeability changes, the main magnetic flux is controlled, and the reactance decreases.

  Since this holds true for the other linear magnetic cores as well, it can operate as a three-phase electromagnetic device whose reactance can be varied.

  As described above, in the magnetic circuit configuration of the present invention, the configuration of the magnetic core and the winding configuration of the main winding and the control winding are symmetrical for each of the three phases, and the balance of the variable reactance characteristics in each of the three phases. Can realize excellent three-phase electromagnetic equipment.

  In addition, a common magnetic path of the main magnetic flux and the control magnetic flux for changing the permeability, controlling the main magnetic flux and varying the reactance is provided for each linear magnetic path around which the main winding is wound. By changing the magnetic resistance of the magnetic path over a wide range, the reactance can be varied over a wide range as compared with the conventional structure.

  FIG. 4 shows an example of the configuration of this three-phase electromagnetic device, and FIG. 4 (a) shows that the connecting magnetic cores connecting the linear magnetic cores form a circular shape as described above, and are used in an electric motor or the like. It can be easily configured with a punched iron core or a stacked iron core. 4 (b) and 4 (c), the shape of the connecting magnetic cores connecting the linear magnetic cores is a straight line, and can be easily constituted by a stacked iron core in addition to the punched iron core. The connecting magnetic core can have various shapes as long as the configuration is equivalent.

  FIG. 5 shows an example of assembling the three-phase electromagnetic device. After the main winding 1 and the control winding 2 are inserted into the linear magnetic core portion having a stacked core structure, the outer connecting magnetic core is assembled. Since it is configured, it is easy to assemble, improve the space factor of the winding, and reduce the weight of the electromagnetic device.

  FIG. 6 is a connection diagram showing another winding configuration example of the three-phase electromagnetic device according to the present invention. Of the 18 linear magnetic cores constituting the three-phase electromagnetic device, six linear magnetic cores 3aa, 3ab, 3ba are shown. 3bb, 3ca and 3cb are connected to the main windings 1aa and 1ab, 1ba and 1bb, 1ca so that the linear magnetic cores 3aa and 3ab, 3ba and 3bb, 3ca and 3cb constituting each phase pair form approximately 60 °, respectively. And 1cb.

  Similar to the above, the magnetic flux density of the common magnetic path part where the control winding magnetic flux and the main magnetic flux are in the same direction increases, the permeability changes, the main magnetic flux is controlled, and the reactance can be varied. Can function.

  The example shown in FIG. 6 is different from the examples shown in FIGS. 1 and 3 in the arrangement of the AC main windings wound around the pair of linear magnetic paths constituting the main windings of the three phases. Although it is a modification, the example of FIG. 7 shown next is a modification of the winding configuration of the main winding wound around the linear magnetic core that is a pair of three phases.

  FIG. 7 is a modification of the example shown in FIGS. 1 and 3, but it is obvious that the example can also be applied to the example shown in FIG.

  The difference from the example shown in FIG. 1 and FIG. 3 is that the directions of main magnetic fluxes generated in the linear magnetic core by the main windings of each phase pair are opposite to each other with respect to the central direction of the linear magnetic core. The example shown in FIG. 7 is that the directions of the main magnetic flux generated in the linear magnetic core by the pair of main windings are the same as each other with respect to the central direction of the linear magnetic core, and are opposed to each other.

  In this configuration, in a symmetrical 18-leg magnetic core configuration, the winding structure for the straight magnetic core of each leg includes the control winding and the main winding, and symmetry is ensured. This contributes to further improvement of the distortion characteristics as well as improvement of the above.

  FIG. 8 shows an example of control characteristics when a three-phase AC voltage is applied to the three-phase electromagnetic device according to the present invention to increase the DC control current Ic.

  FIG. 8A shows an example of the control characteristics of the main winding current. It can be seen that the reactance changes and the main winding current can be varied linearly by increasing the DC control current Ic.

FIG. 8B shows an example of current distortion characteristics of the main winding current, and it can be seen that the main winding current distortion is good regardless of the DC control current Ic.
Further, the above control characteristics are consistent in the range of measurement error in each of the three phases.

  As described above, according to the present invention, the reactance of each of the three phases can be varied at high speed and continuously by adjusting the DC control current.

  FIG. 9 shows the configuration of the magnetic core winding shown in FIG. 1, in which the main winding constituting the electromagnetic device is a primary winding, and the secondary winding 6aa and the primary winding are wound around a linear magnetic core wound with the primary winding 5aa. The secondary winding 6ab is wound around the linear magnetic core wound with the wire 5ab, the secondary winding 6ba is wound around the linear magnetic core wound around the primary winding 5ba, the secondary winding 6bb is wound around the linear magnetic core wound with the primary winding 5bb, and the primary winding. A transformer formed by winding a secondary winding 6ca on a linear magnetic core wound with a winding 5ca and connecting a secondary winding 6cb on a linear magnetic core wound with a primary winding 5cb and connecting them in the same manner as the primary winding. It is a three-phase electromagnetic device with functions.

In FIG. 9, it is assumed that a three-phase AC power source is connected to the primary winding and a three-phase load is connected to the secondary winding, and currents ILu2, ILv2, and ILw2 in the directions indicated by the arrows flow through the respective secondary windings. .
Hereinafter, the first linear magnetic core portion wound with the primary winding 5aa and the second linear magnetic core portion wound with the primary winding 5ab will be described.

  When the control current is not passed, the primary current ILu1 flows through the primary windings 5aa and 5ab so as to cancel the magnetic flux generated by the secondary current, and the transformer operation is shown as a whole.

  When a DC control current Ic is passed through the control winding, a magnetomotive force represented by the product of the number of turns of the control winding and the control current Ic is generated, thereby changing the permeability of the common magnetic path and controlling the main magnetic flux. . For this reason, in accordance with the decrease in the main magnetic flux accompanying the control of the control current, the exciting current increases in order to generate the main magnetic flux necessary for maintaining the voltage between the terminals of the primary winding.

That is, in addition to the transformation function as a transformer, the reactive current flowing into the primary side can be adjusted by continuously adjusting the reactance of the main winding by adjusting the control current.
Since this holds true for other linear magnetic core portions as well, in addition to the function as a transformer, it can be configured as a three-phase electromagnetic device capable of varying reactance.

(Application example)
FIG. 10 is an equivalent circuit showing an application example of the present invention to a reactive power compensator for a three-phase electromagnetic device.
In FIG. 10, a three-phase electromagnetic device according to the present invention and a power capacitor 7 are connected in parallel and inserted in parallel to a transmission line, and the reactive power from the slow phase to the fast phase generated in the system is continuously controlled by controlling the electromagnetic device. Is to compensate.

  As described above in detail, according to the present invention, since it is not necessary to wind the control winding around the connecting magnetic core without providing a tap, the assembly is simple and a gap is not required on the butt surface of the iron core. A three-phase electromagnetic device with excellent three-phase balance that can vary reactance over a wide range can be realized, and the recent increase in power demand and the diversification of loads can flexibly cope with the diversification of loads such as system voltage fluctuations. Provision of power facilities can contribute to the stabilization of power system voltage and more appropriate control of power factor and power flow.

  In addition, various modifications can be made without departing from the scope of the invention.

1 (1aa, 1ab, 1ba, 1bb, 1ca, 1cb) ... main winding, 2 (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k, 2L) ... control winding, 3 (3aa, 3ab, 3ba, 3bb, 3ca, 3cb, 3da, 3db, 3dc, 3dd, 3de, 3df, 3dg, 3dh, 3di, 3dj, 3dk, 3dL, 3e, 3f) ... magnetic core, φa1, φa2, φb1 , Φb2, φc1, φc2 ... main magnetic flux, φdc ... control magnetic flux, 4 ... control circuit, 5 (5aa, 5ab, 5ba, 5bb, 5ca, 5cb) ... primary winding, 6 (6aa, 6ab, 6ba, 6bb, 6ca 6cb) ... secondary winding, 7 ... power capacitor.

Claims (6)

Eighteen linear magnetic cores are arranged radially symmetrically, and each central end and each peripheral end of the linear magnetic core are connected by a connecting magnetic core to form an 18-leg magnetic core,
Winding an alternating current main winding on every two legs on the linear magnetic core, winding a direct current control winding on the linear magnetic core positioned between the linear magnetic cores wound with the alternating current main winding;
Two AC main windings are symmetrically paired to form an AC main winding of each phase of a three-phase AC, and the induction induced in each DC control winding by the three-phase AC current of the three-phase AC main winding. Connect each DC control winding in series or series-parallel so that the power is canceled,
A direct current control current is supplied to a direct current control winding connected in series to generate a control magnetic flux, and the main magnetic flux generated by the current of the alternating current main winding and the magnetic resistance of the common magnetic path of the control magnetic flux are controlled, and the alternating current main winding Three-phase electromagnetic equipment characterized by continuously changing the reactance of   2. The three-phase electromagnetic device according to claim 1, wherein the AC main winding of each phase that is symmetrically paired is two adjacent AC main windings.   The three-phase electromagnetic device according to claim 1, wherein the AC main windings of each of the symmetrically paired phases are two AC main windings arranged in a substantially straight line. Electromagnetic equipment.   The three-phase electromagnetic device according to claim 2 or 3, wherein the directions of the alternating main magnetic fluxes generated in the two linear magnetic cores by the alternating main windings of the respective phases that are symmetrically paired with each other with respect to the central direction of the linear magnetic cores. Three-phase electromagnetic equipment characterized by being in the opposite direction.   The three-phase electromagnetic device according to claim 2 or 3, wherein the directions of the alternating main magnetic fluxes generated in the two linear magnetic cores by the alternating main windings of the respective phases that are symmetrically paired with each other with respect to the central direction of the linear magnetic cores. Three-phase electromagnetic equipment characterized by the same direction.   The three-phase electromagnetic device according to any one of claims 1 to 5, wherein a secondary winding is wound on a linear magnetic core wound with an AC main winding of each phase and a transformer function is provided. machine.

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