JPH0621228U - Three-phase mold transformer - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a compact transformer that is small, lightweight, has low loss, and has reduced manufacturing steps. [Structure] Secondary coils 2u, 2v, and 2w are concentrically wound inside the primary coils 1U, 1V, and 1W for each phase, and coils for three phases are arranged in one mold and assembled. , A three-phase molded transformer made by casting resin and molding it integrally.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a molded transformer, and more particularly to a three-phase one-piece molded transformer.

[0002]

[Prior art]

 Generally, a molded transformer is assembled by molding the primary coil and secondary coil separately with resin, then arranging the primary and secondary coils concentrically for each phase, and inserting the wound iron core into the coil. So-called phase splitting, primary and secondary separation manufacturing methods and structures are used.

FIG. 2 is a schematic sectional view showing a coil of a conventional three-phase molded transformer. In FIG. 2, 11U, 11V and 11W are primary (high voltage) coils, and 12u, 12v and 12w are secondary (high voltage) coils. Low voltage) coil. These primary (high-voltage) coils 11U, 11V and 11W, and secondary (low-voltage) coils 12u, 12v and 12w are separately placed in a mold and molded with a resin, and then the wound core 13 Is inserted into the coil and assembled as a transformer.

As described above, it is necessary to manufacture six coils for one transformer, and a large number of members are required for assembly. In addition, since the coil is usually arranged with the secondary coil (low pressure) inside and the primary coil (high voltage) outside, the mold surface has a high voltage potential, and safety measures such as sufficient space distance are required. , Fences, danger signs, etc. are required.

[0005]

[Problems to be solved by the device]

 However, the structure of such a general mold transformer has a structure in which the primary and secondary coils and each phase are divided and separated as described above. (1) One mold transformer 6 mold coils are required to manufacture, and the man-hours required for molding are large. Also, when assembling, it is necessary to assemble and fix 6 coils as well.

(2) Since air insulation is usually used between the primary and secondary sides, it is difficult to reduce the size in terms of performance.

(3) Similarly, it is necessary to provide an air gap between each phase in order to secure interphase insulation and partial discharge performance.

(4) Since the mold coil surface has a high electric potential, a space and a facility for safety measures are required.

There are problems such as the above.

The present invention has been made in view of the above points, and an object of the present invention is to provide a compact transformer that is small, lightweight, has low loss, and has a reduced number of manufacturing steps.

[0011]

[Means for Solving the Problems]

 In the molded transformer of the present invention, the primary and secondary coils are wound concentrically for each phase, the coils for each phase are placed in one mold and assembled, and then the resin is cast and integrally molded. It is characterized by having done.

[0012]

[Action]

 According to the above configuration, the coil diameter and interphase dimension are reduced by adopting the primary / secondary integrated method for each phase at once, which allows for downsizing, the iron core weight and the primary coil copper amount are reduced, and the transformer weight is also reduced. It gets lighter. Also, since one unit can be manufactured by casting once, casting work becomes easier and the weight of the transformer becomes lighter. Also, since one unit can be manufactured by casting once, man-hours such as casting and demolding can be greatly reduced. In addition, the assembly becomes easier and the work man-hours can be reduced.

[0013]

【Example】

 Hereinafter, an embodiment of the molded transformer of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the molded transformer of the present invention. In FIG. 1, 1U, 1V and 1W are primary (high voltage) coils, 2u, 2v and 2w are secondary (low voltage) coils. ) A coil. A spacing member 3 that can be integrated by molding is provided on the inner side of each of the primary coils 1U, 1V, and 1W, and the secondary coils 2u, 2v, and 2w are wound so as to be arranged concentrically with a predetermined spacing. ing. Assemble the coils for three phases in one mold, and perform the work such as connecting the coils and attaching primary and secondary terminals. After assembling the mold, and after the steps such as drying and preheating, the resin is cast and molded to form a total of 6 coils. Next, after removing the mold, the conductive layer 4 is applied to the entire surface of the mold excluding the terminal portion by metal spraying or coating with a conductive paint to obtain the ground potential. However, at this time, a non-conductive portion is locally provided by the conductive layer 4 so as not to form a short circuit, and one turn is not formed. After that, the wound iron core 5 is inserted into the coil and assembled.

[0015]

[Effect of device]

 As described above, in the molded transformer of the present invention, (1) the coil diameter and interphase dimension can be reduced and the size can be reduced by adopting the one-phase, primary-secondary integrated system for each phase, the weight of the core and the copper of the primary coil. The volume is smaller and the transformer weight is also lighter.

(2) Since the weight of the iron core and the amount of the primary coil copper are reduced, the loss as a transformer can be reduced.

(3) Since the dangerous area can be narrowed by using the conductive layer on the surface, it is possible to significantly reduce the installation floor area together with the miniaturization. Also, the safety level is improved.

(4) Since one unit can be manufactured by casting once, the number of man-hours for casting can be significantly reduced.

(5) Assembling becomes easy, and the number of work steps can be reduced.

Excellent effects such as

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a molded transformer of the present invention.

FIG. 2 is a schematic sectional view showing a conventional mold transformer.

[Explanation of symbols]

 1U ... Primary U-phase coil 1V ... Primary V-phase coil 1W ... Primary W-phase coil 2u ... Secondary u-phase coil 2v ... Secondary v-phase coil 2w ... Secondary w-phase coil 3 ... Spacing member 4 ... Conductive layer 5 ...... Iron core

Claims (2)

[Scope of utility model registration request] 1. In a mold transformer comprising a primary coil and a secondary coil wound concentrically, coils for three phases are placed in one mold and assembled, and then a resin is cast to be integrated. A three-phase molded transformer characterized by being molded. 2. The three-phase molded transformer according to claim 1, wherein a conductive layer that does not form one turn is provided on the mold surface.