JPS58225621A - Three-phase wound core - Google Patents

Abstract

PURPOSE:To reduce magnetic flux density of joint part and improve core loss property by arranging the joint part of internal core to the straight part of yoke and the joint part of external core to the corner part thereof. CONSTITUTION:A three-phase wound core is formed by adjacently placing the one legs of a plurality of internal wound cores 1, 2 each other in contact and by arranging an external wound core 3 at the outside thereof. The joint part 4 of the internal wound cores 1, 2 of the three-phase wound core is arranged at the straight part of yoke, while the joint part 5 of external wound core 3 is arranged at the corner part. Magnetic flux distribution of three-phase wound core is divided into the magnetic flux distribution 6 of corner part, magnetic flux distribution of 7 of core and that 8 of yoke. Thereby, magnetic flux distribution of joint part can be reduced and loss of core can also be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a three-phase tripod wound core, and more particularly to a three-phase wound core in which loss is reduced by providing a joint section at the corner portion of the outer wound core where magnetic flux density is low. be.

As shown in Figure 1, the joint part (henching part) of the outer wound core of the conventional three-phase tripod wound iron core was provided in the straight part of the yoke, so the magnetic flux density at the joint part became high and iron loss increased. There was a drawback.

Furthermore, there is conventionally a single-phase wound core in which a joint portion is provided at a corner portion. However, if this method is adopted and all the joints of the three-phase tripod-wound core are provided at the corners, the joints will be provided at locations where the magnetic flux density of the inner-wound core is high, resulting in increased iron loss. There is.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a low-loss three-phase tripod-wound core.

A feature of the present invention is that the magnetic flux distribution of the three-phase tripod-wound core exhibits a biased magnetization phenomenon inward due to the difference in magnetic path length, and this phenomenon is particularly noticeable at the corners, so the magnetic flux density at the corner of the outer-wound core is By focusing on the fact that the magnetic flux density becomes small, and by providing a joint portion in this portion, the magnetic flux density at the joint portion is reduced and iron loss is improved.

An embodiment of the present invention will be described below with reference to FIG.

In this embodiment, the joint part 4 of the inner one-turn iron core 1.2 is provided in the straight part of the yoke, and the joint part 5 of the outer one-turn iron core 1.2 is provided in the corner part to form a tripod-wound iron core.

The magnetic flux of the three-phase tripod-wound core exhibits a biased magnetic flux distribution as shown in FIG. 3 because it flows inside the inner-wound core where the magnetic path length is short. This tendency is particularly noticeable at corners. Furthermore, since the magnetic flux at the joint flows in a traversal manner between the copper strips as shown in FIG. 4, the magnetic flux density at the joint becomes high. As is already known, the magnetic flux density is 2
Since iron loss increases in proportion to the power of As mentioned above, in the case where the joint part is provided in the corner part, even if a traverse occurs between the copper strips, the magnetic flux density will not be as high as in the joint part provided in a straight part as shown in Figure 1. The iron loss at this point does not increase that much.

As a result of comparative experiments with an average magnetic flux density of 1.75 T between cases in which the joint portion was provided in a straight portion and cases in which it was provided in a corner portion, an improvement in iron loss characteristics of approximately 8 to 10% was observed.

As is clear from the above description, according to the present invention.

Since the magnetic flux density at the joint part can be made smaller than when it is provided in the straight part, the iron loss characteristics can be improved by about 8 to 10%.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a conventional three-phase tripod-wound core and its joint part. FIG. 2 is an explanatory diagram of a three-phase tripod-wound core according to an embodiment of the present invention. FIG. 6 is a three-phase tripod-wound core. Magnetic flux distribution state diagram. FIG. 4 is an explanatory diagram showing the flow of magnetic flux in the joint portion. 1... Inner (4111-wound core, 2... Inner-wound core, 3
...Outer (1111 core, 4...Joint part of inner core, 5...Joint part of outer core, 6...
・Magnetic flux distribution at the corner. 7... Magnetic flux distribution in a part of the core - 8... Magnetic flux distribution in the yoke part, 9... Silicon steel strip, 10... Magnetic flux flowing through each silicon steel strip.

Claims (1)

[Claims] A plurality of inner single-turn cores with one leg adjacent to each other and an outer (1111-turn core) provided overlappingly on the outside of these inner-wound cores are provided, and the joint part of the inner-wound core is connected to the yoke straight part. A three-phase wound core characterized in that the joint portion of the outer wound core is arranged at a corner portion.