JP4330840B2 - Three-phase reactor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-phase reactor device to which a function of changing the inductance of a main winding is added .
[0002]
[Prior art]
Generally, lapis lazuli Akutoru which have a function of a variable inductance is provided a gap inside the core, it was changing the inductance mechanically altering the size of the gap. For example, in a reactor having a variable inductance function, as shown in FIG. 5 , an upper iron core 2 is disposed on a lower iron core 1, and AC main windings 4R, 4S, 4T of respective phases are wound around leg iron cores 3a, 3b, 3c. The structure is such that the size of the gaps 5a, 5b, 5c between the lower iron core 1 and the upper iron core 2 is changed by turning and moving the upper iron core 2 up and down mechanically.
[0003]
However, in the conventional movable iron core structure, the upper magnetic core 2 is movable, so that the structure is complicated, the weight is heavy, and there are movable parts, so that there is a problem that noise is easily caused due to electromagnetic vibration. Furthermore, since it is mechanically operated, there is a problem that the response speed is slow and the inductance cannot be adjusted instantaneously.
[0004]
In addition, a reactive power control device that balances the generation and absorption of reactive power is provided to keep the voltage of the power system constant. As shown in FIG. 6 , the reactive power control apparatus includes a shunt reactor 7 in parallel with the power factor improving capacitor 6, and a semiconductor device 8 such as a thyristor is connected in series with the shunt reactor 7. The current of the shunt reactor 7 is controlled by switching.
[0005]
In a general power system, delayed reactive power increases with an increase in load. Therefore, in this reactive power control device, the power factor is improved by the power factor improving capacitor 6 at heavy load. On the other hand, since the delayed reactive power due to the load decreases at light loads, the shunt reactor 7 suppresses the voltage increase at the power receiving end and stabilizes the voltage of the power system.
[0006]
However, the semiconductor device 8 such as a thyristor requires a control device for performing high-speed switching, and has a drawback of low strength against overcurrent and overvoltage. By adjusting the order using a reactor having a core structure of movable FIG as a shunt reactor 7 shown in FIG. 6 inductance is also conceivable to omit the semiconductor device 8. However, when a reactor having a movable iron core structure is used, it has not been used as a reactive power control device because of the problems described above.
[0007]
[Problems to be solved by the invention]
The present invention improves the above-mentioned problems, provides a three-phase reactor device that is suitable as a reactive power control device because it can reduce the size of the device without requiring mechanical operation, has excellent responsiveness, and has high strength against overcurrent and overvoltage. To do.
[0008]
[Means for Solving the Problems]
The three-phase reactor device according to claim 1 of the present invention has a core structure in which three core inner core legs around which a main winding is wound are connected integrally so that a single-phase outer iron core is in series. The main AC winding of each phase is wound around three central inner cores, and the control winding is wound around the outer frame-shaped core consisting of the side leg cores of each phase. connect the control winding so that the voltage cancel each other being, to generate a DC control flux circulation in one direction on the outside of the frame-shaped iron core, the magnetic resistance of the common magnetic path of the main magnetic flux and the DC control flux It is characterized by controlling and varying the inductance of the main winding .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 shows a three-phase reactor device 9. An iron core 10 constituting the device is a single-phase outer iron core in which side leg iron cores 12xa and 12ya are arranged on the left and right sides of a central inner leg iron core 11a for the first phase. Similarly, the second phase and the third phase are respectively composed of 11b, 12xb, 12yb and 11c, 12xc, 12yc, and the three inner cores 11a, 11b, 11c in the center are integrated as a whole. It has a lattice structure connected to.
[0010]
The AC main windings 4R, 4S, 4T of the respective phases are wound around the central inner leg cores 11a, 11b, 11c arranged in series with the iron core 10, respectively, and the side leg cores 12xa constituting the frame-shaped iron core 13 are wound. , 12ya, 12xb, 12yb, 12xc, 12yc are wound with control windings 14xa, 14ya, 14xb, 14yb, 14xc, 14yc, respectively, and a DC current is passed through the control windings 14xa, 14ya, 14xb, 14yb, 14xc, 14yc. It is supposed to do.
[0011]
The AC main windings 4R, 4S, and 4T have the same polarity so that magnetic fluxes in the same direction are generated with respect to the common magnetic path composed of the central inner cores 11a, 11b, and 11c. In addition, since the control windings 14xa, 14ya, 14xb, 14yb, 14xc, and 14yc are induced with an AC voltage by an AC magnetic flux, when the first phase is described as an example, an induced voltage generated by the AC magnetic flux at the control windings 14xa and 14ya is The two phases 14xb and 14yb and the third phase 14xc and 14yc are connected in the same manner in such a manner that they are connected in series so as to cancel each other. At this time, the control windings 14xa, 14ya, 14xb, 14yb, 14xc, and 14yc generate a DC control magnetic flux that circulates in one direction in the frame-shaped iron core 13.
[0012]
In the three-phase reactor device configured as described above, in a state where no control current is passed, the AC magnetic flux (φr, φs, φt) generated from each AC main winding 4R, 4S, 4T is the side leg core 12xa of each phase. , 12ya, 12xb, 12yb, 12xc, and 12yc, and circulates the iron core of each phase portion independently, it operates as an independent inductance device for each phase.
[0013]
In this state, when a direct current is passed through the control windings 14xa, 14ya, 14xb, 14yb, 14xc, and 14yc, the direct current control magnetic flux φdc flows so as to circulate in the frame-shaped iron core 13 in one direction. As a result, the magnetic permeability of the frame-shaped magnetic core 13 decreases as the magnetic flux density increases, so that the alternating magnetic flux (φr, φs, φt) is less likely to flow through the frame-shaped iron core 13 and the central inner leg cores 11a, 11b, 11c. By acting so as to cancel each other, the inductance of the AC main windings 4R, 4S, 4T is reduced.
[0014]
As a result of examining the characteristics of the three-phase reactor device 9 having the above configuration, it was confirmed that the inductance gradually decreased as the control current was increased as shown in FIG. When this three-phase reactor device 9 is incorporated in the reactive power control device as shown in FIG. 3 and the change in the delayed reactive current due to the control current is measured, the delayed reactive current increases as the control current increases as shown in FIG. It was confirmed that it increased almost linearly and could be continuously varied.
[0015]
As for the connection of the control windings 14xa, 14ya, 14xb, 14yb, 14xc, 14yc, all the control windings are connected in series and then connected to a control DC current circuit, as well as “14xa, 14ya”. ”,“ 14xb, 14yb ”,“ 14xc, 14yc ”for each phase and connected in parallel to the control DC current circuit,“ 14xa, 14xb, 14xc ”,“ 14ya, 14yb, 14yc ” And a method of connecting in parallel to a direct current circuit for control. That is, the configuration of the control winding is not limited as long as the voltage induced in the control winding by the AC magnetic flux is canceled and the DC control magnetic flux circulating in one direction can be generated in the frame-shaped iron core 13.
[0016]
【The invention's effect】
As described above, according to the three-phase reactor device according to the present invention, the control winding is provided on the outer frame-shaped iron core, and the inductance can be adjusted by flowing a direct current therethrough. There is no part, the responsiveness is fast, it can be continuously varied, the apparatus can be miniaturized, the noise is small, and the reliability can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a front view of a three-phase reactor device according to an embodiment of the present invention.
FIG. 2 is a graph showing the relationship between control current and inductance of the three-phase reactor device of FIG. 1;
FIG. 3 is an explanatory view showing a reactive power control device incorporating the three-phase reactor device of FIG. 1;
FIG. 4 is a graph showing a relationship between a control current and a delayed reactive current in a reactive power control device incorporating a three-phase reactor device .
FIG. 5 is a front view showing a conventional movable inductance device.
FIG. 6 is an explanatory diagram showing a reactive power control apparatus incorporating a conventional semiconductor device .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Lower iron core 2 Upper iron core 3a, 3b, 3c Leg iron core 4R, 4S, 4T AC main winding 5a, 5b, 5c Gap 6 Power factor improvement capacitor 7 Shunt reactor 8 Semiconductor device 9 Three-phase reactor device 10 Iron core 11a, 11b, 11c Inner leg iron core
1 2xa, 12ya, 12xb, 12yb, 12xc, 12yc Side leg core 13 Frame-shaped iron core
1 4xa, 14ya, 14xb, 14yb, 14xc, 14yc Control winding

Claims (1)

A single-phase outer iron-type magnetic core has a core structure in which three central inner cores around which the main winding is wound are connected in series so that they are connected in series. Along with winding the main winding, the control winding is wound around the outer frame-shaped core consisting of the side leg cores of each phase so that the voltages induced by the AC main magnetic flux cancel each other out. A DC control current is applied to the outer frame-shaped iron core to generate a DC control magnetic flux that circulates in one direction, and a magnetic resistance of a common magnetic path of the main magnetic flux and the DC control magnetic flux is controlled. A three-phase reactor device characterized by varying the inductance of the winding.

Images