JPS62239511A - Stationary induction apparatus - Google Patents

Abstract

PURPOSE:To reduce the iron loss of an iron core as well as to contrive accomplishment of the miniaturization and the highly efficient operation of the iron core by a method wherein a coil for formation of a DC magnetic field is wound on the iron core, and a DC current is applied to the coil. CONSTITUTION:A coil 6, to be used for formation of a DC magnetic field, is wound on the iron core 1 on which a primary coil 2 and a secondary coil 3 are wound. When an induction machine is used, an AC power source 4 is given to the coil 2, and a DC power source 7 is given to the coil 6. As a result, the iron core 1 is excited by a DC magnetic field, and the iron loss generating by the AC excitation based on the coil 6 can be reduced. The iron loss generating when the induction machine is operated can also be reduced. Accordingly, the miniaturization and the highly efficient operation of the iron core can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to stationary induction equipment such as transformers and reactors.

(Prior Art) Recently, in stationary induction devices, it has been considered to use a ribbon made of an amorphous magnetic alloy as a high-frequency iron core, and its practical use is progressing. This amorphous ribbon has a relatively high specific resistance, so iron loss is small in the high frequency range, and iron-based amorphous ribbons have a particularly high saturation magnetic flux density and Curie point, making it possible to miniaturize and increase the iron core. It is extremely effective in increasing efficiency.

By the way, when using iron-based amorphous for the iron core,
Various treatments have been used to reduce iron loss characteristics in the high frequency range.

(1) One of the methods is to perform heat treatment such as annealing. The usefulness of this annealing is that it removes the distortion caused by the ultra-rapid heat treatment during amorphous manufacturing, thereby reducing hysteresis loss, and reducing local abnormal eddy current loss near the domain wall by refining the magnetic domain. It's for a purpose. This abnormal eddy current loss has a large effect on iron loss in the high frequency region.

(II) There are various other treatment methods, but for example, Japanese Patent Application Laid-Open No. 148314/1983 proposes a method that improves iron loss by about 10% by applying compressive force during annealing. .

(Problems to be Solved by the Invention) However, although various treatments have been carried out to reduce iron loss as described above, all of them have a limit to the reduction of iron loss, and in static induction equipment, , it is required to further reduce iron loss. Such problems also occur to some extent when iron cores made of materials other than amorphous are used.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a stationary induction device that can substantially reduce iron loss of an iron core, and further improve the size and efficiency of the iron core.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides for winding a coil for forming a DC magnetic field around an iron core around which a secondary coil and a secondary coil are wound, and when using an induction device, forming a DC magnetic field. A direct current is passed through the coil for use.

(Function) When direct current is applied to the coil for forming a direct current magnetic field, the iron core is excited by the direct current magnetic field, reducing the iron loss that would occur due to alternating current excitation based on the -order coil, thereby reducing iron loss during operation. This aims to substantially reduce iron loss.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

First of all, Figure 1 shows the whole in principle,
In the figure, 1 is an iron core consisting of split iron cores 1a and 1b, which is made of, for example, Amorphous 2605 manufactured by Allied Co., Ltd.
It is made by continuously winding an amorphous ribbon called S3A. The cross-sectional areas of the divided cores 1a and lb are as follows: One of the divided cores 1a has a cross-sectional area of A1, and the other of the divided cores 1b has a cross-sectional area of A.
The settings are as follows. A primary coil 2 and a secondary coil 3 are commonly wound around this iron core 1. When the device is in use, when AC type #, 4 is manually applied to the secondary coil 2, power is supplied to the load 5 connected to the secondary coil 3. 6
is a DC magnetic field forming coil consisting of two divided coils 6a and 6b, and these are the divided iron cores 1a and lb of the iron core 1.
The windings are respectively wound and connected in series, and the number of turns is set to be AN-A''N', where N and If'' are the winding numbers. This DC magnetic field forming coil 6 is a DC magnetic field forming coil 6.
i7 is applied, and a variable resistor 8 is connected to adjust the applied voltage. still,
In this case, the AC excitation is 5 KHz.

The operating magnetic flux density is 0.1, Q, 3.0.4T.

In this embodiment with the above configuration, when using the device, the AC power supply 4
When the voltage is applied to the primary coil 2 and the DC power source 7 is applied to the DC magnetic field forming coil 6, the characteristics shown in FIG. 2 are obtained. In this FIG. 2, the magnetic flux density is set to 0. IT, the horizontal axis is the DC magnetic field (A/cm), and the vertical axis is the iron loss (W
/kg), and the other vertical axis shows the noise (dB), the characteristic line J shows the iron loss change, and the characteristic line shows the noise change.

In this case, the divided coil 6a wound around one divided core 1a of the DC magnetic field forming coil 6 and the other divided core 1
In the split coil 6b wound around the split coil 6b, the induced voltages have approximately the same absolute value and opposite phases, so no voltage is generated between the terminals of the variable resistor 8 and the DC power supply 7, and therefore It is not a load. Direct current I flows through the direct current magnetic field forming coil 6 from the direct current power source 7, thereby generating magnetic fields of N I/L and N-I/L in the divided iron cores 1a and lb, respectively (L: magnetic path length). This magnetic field is O12~1
．． By adjusting the variable resistor 8 so that the magnetic field falls within 0 (A/cm), the iron loss of the iron core 1 can be reduced to 0 (A/cm).
) can be reduced to 25%.

Since iron loss can be reduced in this way, the iron core 1 can be made smaller and more efficient.

Also, as can be seen from Figure 2, 0. 25 (A/cm)
Set variable resistor 8 etc. to obtain a nearby DC magnetic field! Noise reduction can be achieved by setting the j section.

Figure 3 shows the iron loss characteristics when the magnetic flux density is 0.3T and 0.4T, the characteristic line J1 shows the iron loss characteristics when the magnetic flux density is 0.3T, and the characteristic line J2 shows the iron loss characteristics when the magnetic flux density is 0.3T. The iron loss characteristics in the case of 0.4T are shown. In the case of FIG. 3, the DC magnetic field region where low core loss can be obtained is narrow, but the magnetic flux density is 0.
If it is 7T or less, it is possible to achieve low iron loss.

Note that the appropriate DC magnetic field range varies depending on the abrasive quality of the iron core, heat treatment conditions, operating frequency, and magnetic flux density, but this can be dealt with by adjusting the variable resistor 8 as in this embodiment.

In the above embodiment, amorphous was used as the material of the iron core 1, but the present inventors have found that the same tendency for reduction of iron loss can be observed in the case of iron cores made of other materials such as silicon steel or a portion of ferrite. It has been experimentally confirmed that this is shown.

[Effects of the Invention] As is clear from the above description, the present invention can operate in a magnetization region where less iron loss occurs by forming a DC magnetic field in the iron core, and can substantially reduce the iron loss of the iron core. This has the excellent effect of further reducing the size of the iron core and increasing its efficiency.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, Fig. 1 is a diagram showing the principle of an induction device, Fig. 2 is a DC magnetic field-iron loss-noise change characteristic diagram, and Fig. 3 is a diagram showing the magnetic flux density in Fig. 2. FIG. 4 is a DC magnetic field-iron loss change characteristic diagram when the values are different. In the figure, 1 is the iron core, 2 is the primary coil, 3 is the secondary coil, 6
8 is a coil for forming a DC magnetic field, and 8 is a variable resistor. Agent: Patent Attorney Nori Chika (G.
Hiroshi Mimata Fuminao Mitsuru (A/cm)
) Fig. 2 DC F1 elbow field (A/cm) Fig. 3

Claims (1)

[Claims] 1. A stationary device in which a primary coil and a secondary coil are wound around an iron core, wherein a DC magnetic field forming coil is wound around the iron core, and a DC current is passed through the DC magnetic field forming coil. shaped induction equipment.