JPS6153802B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a high-frequency low-impedance electric line used in a three-phase high-frequency power circuit.
In particular, the present invention relates to a high-frequency low-impedance electric line suitable for use in 400Hz power supply circuits for large computers, etc. Electrical lines used in power circuits operating at high frequencies ten to several tens of times higher than the commercial frequency have extremely large reactances, resulting in a large voltage drop in the electrical line, and an unbalanced voltage drop between phases. become. As a means to solve such problems, (a) Increase the conductor size. (b) Use a coaxial cable. (c) Use multiple small cables connected in parallel. Possible methods include: However, with method (a),
Although the resistance component becomes smaller, the reactance component hardly decreases and the effect is small. In method (b),
There are many cable manufacturing steps, which leads to poor productivity and makes cable terminal processing complicated. Furthermore, there is a drawback that an imbalance occurs in the impedance of the three phases. Method (c) has the disadvantage that a large installation space is required to maximize the effect. For this reason, a low-impedance electric line for high frequency has been proposed in which three-phase units, each consisting of three phases divided into small sections, are arranged and twisted together at electrically balanced positions on the circumference. When using a cable with a similar configuration in a 400Hz power supply circuit for a large computer, etc., as shown in Figure 1, pulsed high-frequency noise may enter the passive end of the power supply circuit of computer 1 from the power supply 2 side. In order to remove
There is a drawback that a line filter 4 with a large capacity of about [MF] must be inserted. The present invention was made to solve these difficulties, and by applying a conductive layer to the outer periphery of each insulated wire core that constitutes the above-mentioned high-frequency low-impedance electric line, the cable itself has the function of a line filter. The purpose is to provide high-frequency, low-impedance electrical lines. Hereinafter, the present invention will be explained based on the drawings of one embodiment. In Fig. 2, the three-phase unit R ₁ , S ₁ , T ₁
~Insulated wire core 5 with conductive layer forming R ₁₂ , S ₁₂ , T ₁₂
As shown in FIG. 3, the conductor 6 is composed of a conductor 6, an insulator 7 made of polyethylene, rubber, soft vinyl chloride resin, etc. extruded and coated thereon, and a shielding layer 8 provided around the outer periphery of the conductor 6. The dielectric constant of the insulating material mentioned above is that of polyethylene.
2.3, 4.0 for rubber, and 7.0 for soft vinyl chloride resin, but these materials may be further increased in dielectric constant to use an insulating material with a dielectric constant of about 10 to 30. In this case, there is an advantage that a large capacitance can be obtained even if the electric line is short. The conductive layer 8 is made of horizontally wound copper tape or aluminum tape, or braided conductive wire such as copper wire or aluminum wire, but it increases the flexibility of the electric wire itself and reduces the finished outer diameter. In order to reduce the size, it is desirable to use a laminated metal tape in which a thin film layer of plastic such as polyimide or polyester is laminated on one side of a thin metal tape such as aluminum. When using laminated metal tape, it is wound or attached vertically with the metal side facing outward. Therefore, the three-phase unit R ₁ , S ₁ , T ₁ , R ₂ , S ₂ ,
Two sets of T ₂ are twisted together so that each insulated wire core 5 with a conductive layer is arranged on the minimum circumference to constitute a first layer, and on top of this first layer, four sets of 3 The phase units R ₃ , S ₃ , T ₃ to R ₆ , S ₆ , and T ₆ are twisted together in the opposite direction to the twisting direction of the first layer to form the second layer.
On this second layer are six three-phase units R ₇ ,
S ₇ , T ₇ to R ₁₂ , S ₁₂ , T ₁₂ have the twisting direction the same as the twisting direction of the first layer, and the twisting pitch is different from the twisting pitch of the first layer (any size is fine),
They are twisted together to form the third layer. The three-phase unit R ₁ , S ₁ , T ₁ to R ₁₂ , S ₁₂ , T ₁₂
are held together by a restraining tape 9, and a protective coating layer 10 made of soft vinyl chloride resin or the like is provided thereon. The restraining tape 9 is made of the aforementioned laminated metal tape or the like, and is wound horizontally with the metal surface of the tape facing inside. In the figure, reference numeral 11 indicates a grounding conductor made of stranded annealed copper wire, etc., and this conductor is attached vertically along the length of the cable inside the restraining tape 9 so as to be in electrical contact with the metal surface of the tape. ing. In the high-frequency low-impedance electric line of the present invention described above, a conductive layer is provided on the outer periphery of the three insulated wire cores constituting the three-phase unit, so a large ground capacitance is obtained, and the electric wire The line itself can function as a line filter. Incidentally, the capacitance of the high frequency low impedance electric line according to the present invention is about five times that of a general cable of the same size. Therefore, the present invention can provide a low-impedance electric line for high frequencies that does not require a line filter to be attached to the computer body as in the prior art.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a high-frequency low-impedance electric line, Figure 2 is an explanatory diagram showing the arrangement of insulated wire cores with a conductive layer in the high-frequency low-impedance electric line of the present invention, and Figure 3 is an insulated wire with a conductive layer. This is a cross section of the wire core. DESCRIPTION OF SYMBOLS 1... Computer, 4... Line filter, 5 ... Insulated wire core with conductive layer, 8... Conductive layer, 1
0...Protective coating layer.

Claims (1)

[Claims] 1. In an electric line comprising a plurality of sets of three-phase units each consisting of three insulated wire cores and a protective covering layer 10 provided on the outer periphery of the cable core, the cable core has a conductive layer in which each layer is an integral multiple of three. It has a multilayer twisted structure consisting of insulated wire cores 5 with conductive layers, and each three-phase unit R, S, T is constituted by three adjacent insulated wire cores with conductive layers in each layer, and these insulated wires with conductive layers A low impedance electric line for high frequency use, characterized in that the cores are twisted in different directions in each layer.