JPS59141208A - Structure of core for electric apparatus - Google Patents

Abstract

PURPOSE:To prevent the titled device from local generation of magnetic saturation, and moreover to improve distortion of the magnetic flux density waveform by a method wherein an inserting material having different magnetic characteristics from a magnetic substance is provided in the magnetic path of the core consisting of the magnetic substance having nonlinearly magnetic characteristics, and size of the inserting material thereof is so decided as to make magnetic flux densities at the respective parts of the core to become to nearly the sine waves respectively. CONSTITUTION:When the titled core is to be applied to a single-phase transformmer, a gap is provided in series to the magnetic path of the core consisting of a silicon steel sheet having the directional propery. The gap thereof can be easily decided according to numerical analysis of the finite element method, etc. The inserting material at this case is air. By providing the gap in such a way, the magnetic flux density waveforms of the respective parts become to the waveforms close to the sine wave as shown in the figure. It is not necessary to limit the inserting material thereof to air, and any material having the different magnetic characteristic from the core is favorable. The core thereof can be applied to a multiphase transformer, etc.

Description

[Detailed description of the invention] The present invention relates to the structure of an electrical equipment core.

In the conventional iron core structure as shown in Fig. 1 (only 〃 is shown), which is made by simply butting electric iron plates on the AB edge line, the magnetic path length is different between the window side CAD and the outer EBF of the iron core, so two figures are shown. The magnetic flux density waveform in the a-f section becomes a distorted wave with different peak values as shown in FIG. That is, the magnetic flux density waveform of each part includes harmonic components, and the magnetic flux density on the window side is larger than that on the outside (1). Therefore, compared to the case where the magnet is uniformly magnetized with a sinusoidal magnetic flux, the iron loss increases considerably.

Therefore, the present invention aims to prevent the occurrence of local magnetic saturation and improve the distortion of the magnetic flux density waveform by inserting a material in the magnetic path that has different magnetic properties from the magnetic material constituting the iron core. shall be.

In recent years, with the development of numerical analysis techniques such as the finite element method and the development of electronic computers, numerical analysis of magnetic fields that takes into account the nonlinearity of magnetic properties has become easier, and the analysis results have become reliable. Therefore, numerical analysis using the finite element method is applied to determine the dimensions of the inserted material whose magnetic properties are different from those of the iron core. That is, in the conventional finite element method, the potential is taken as an unknown quantity, but in the analysis used in the present invention, predetermined conditions, such as magnetic flux density, etc. are set, and the dimensions of the inserted material are also analyzed as an unknown quantity to determine the potential and dimensions.

Here, as a preferred embodiment, an example of application to a single-phase transformer core will be shown. In this case, an air gap (2) as shown in Figure 3 is provided in series with the magnetic path of the iron core made of grain-oriented silicon steel plates. This void can be easily determined by numerical analysis such as the finite element method. The intercalating material in this case is air. FIG. 4 shows the magnetic flux distribution when the magnetic flux is at its maximum, and FIG. 5 shows the magnetic flux density waveforms at various parts. By providing the air gap in this way, the magnetic flux density waveform of each part becomes a waveform close to a sine wave.

Note that this inserted substance does not need to be air.

It is sufficient if the magnetic properties are different from those of the iron core.

Further, although the description has been made using a single-phase transformer, it can of course be applied to multi-phase transformers, etc.

The above two aspects of the present invention are achieved by providing an iron core of an electric device with a core having magnetic properties different from those of the iron core.

Adjust the magnitude of magnetic flux density and waveform distortion in each part of the iron core,
Minimize iron loss.

[Brief explanation of drawings]

Fig. 1 shows the conventional iron core structure, Fig. 2 shows the magnetic flux density waveform in the direction of the arrow at each part shown in Fig. 1, Fig. 3 shows the iron core structure of the embodiment of the present invention, and Fig. 4 shows the structure shown in Fig. 3. FIG. 5 shows the magnetic flux density waveform in the direction of the arrow in each part shown in FIG. 3 (3). (4) Figure 3 Figure 4 Procedural amendment (method) % formula % 1. Indication of case Patent Application No. 16704 of 1988 2.
Title of the invention Electrical equipment core structure 3, Relationship to the case of the person making the amendment Patent applicant address (residence) 680-994 Hiroya, Okayama City, Okayama Prefecture, Date of amendment order May 11, 1980 5, Subject of amendment
drawing

Claims (1)

[Claims] (1) An inserted material having different magnetic properties from the magnetic material is provided in the magnetic path of an electrical equipment core made of a magnetic material having nonlinear magnetic properties, and the dimensions of the inserted material are determined by the magnetic flux density of each part of the core. An iron core structure characterized by having been determined by numerical analysis so that each time becomes a substantially sinusoidal wave.