JPH0113403Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a capacitor-type potential transformer.

[Technical background of the invention and its problems]

Generally, a capacitor-type voltage transformer consists of a transformer unit 1 that houses a transformer and insulating oil in a tank, and a large number of capacitors in an insulator tube 2, as shown in Figure 1. It has a coupling capacitor section 4 that accommodates the element 3 and insulating oil, and a terminal 5 that is provided on the coupling capacitor section 4 and is connected to the line, and has an internal structure that prevents expansion and contraction of the insulating oil in the coupling capacitor section 4. and a head cap 7 having an absorbing expansion chamber 6.

A large number of capacitor elements 3 of the coupling capacitor section 4
are stacked and housed in the insulator tube 2 by being tightened by insulating rods 9 via tightening plates 8 provided above and below. In this case, due to storage space within the insulator tube 2, there is some margin between the clamping plate 8 above the capacitor element 3 and the insulator cover 10 forming the bottom plate of the head cap above the insulator tube 2. Therefore, to prevent the capacitor element 3 from moving, a coil spring 11 is inserted between the insulator cover 10 and the upper clamping plate 8, and the compressive repulsive force of the coil spring 11 is used to fix the capacitor element 3. Here, the upper clamping plate 8 is connected to the electrode of the uppermost capacitor element 3 to have the same potential so as not to become a floating electrode, so the electrode of the uppermost capacitor element 3 is connected to the upper clamping plate 8, the coil It will be connected to the head cap 7 via a spring 11.

Therefore, in this state, a current flows through the coil spring 11, and the coil spring 11 acts as an electromagnetic coil to generate inductance. For this reason, especially the coupling capacitor section 4 of a capacitor-type voltage transformer
When communication is performed using a power line carrier wave, the inductance caused by the coil spring 11 causes an apparent change in the capacitance of the coupling capacitor section 4, which significantly affects the characteristics of the power line carrier coupling filter. Therefore, in order to eliminate this effect, the upper clamping plate 8 and the insulating tube cover 10 are connected using separate parallel connection lead wires 12, thereby eliminating the electromagnetic coil action of the coil spring 11, suppressing the inductance, and improving the characteristics. I was trying. In addition, 1
3 is a lead wire connecting the cover 10 and the terminal 5. However, in this way, the connection lead wire 12
Providing a
There was a risk of wire breakage and the product was expensive.

[Purpose of invention]

The present invention eliminates the drawbacks of the prior art described above, and provides a capacitor-type voltage transformer that prevents inductance from occurring in the coil spring without using connection leads, and that allows easy assembly of the coupling capacitor section. The purpose is to provide.

[Summary of the idea]

In order to achieve this object, the present invention has two coils wound in opposite directions and having the same number of turns between the upper clamping plate and the insulator cover, which are electrically connected to the electrode of the uppermost capacitor element. A non-inductive double coil spring with coil springs arranged concentrically is inserted, and the compressive repulsive force of this double coil spring is used to electrically connect the upper clamping plate and the insulator cover, and to fix the capacitor element. This is what I decided to do.

[Example of idea]

An embodiment of the present invention shown in the drawings will be described below. The same parts as in Fig. 1 are given the same symbols in the second
In the figure, a large number of capacitor elements 3 constituting a coupling capacitor section 14 are stacked, and are clamped from above and below by insulating rods 9 via clamping plates 8 which also serve as electrodes, and housed in an insulating tube 2 together with insulating oil. A clamping plate 8 above this capacitor element 3
is connected to the electrode of the uppermost capacitor element 3 and set to the same potential. Between the upper clamping plate 8 and the insulator cover 10 are concentric double coil springs 15 wound in opposite directions and having the same number of turns.
is inserted, and the capacitor element 3 is fixed within the insulator tube 2 by the compressive repulsive force of this double coil spring 15. At the same time, this double coil spring 15 electrically connects the insulator cover 10 and the upper clamping plate 8, and connects the electrode of the uppermost capacitor element 3 to the cover 10, the lead wire 13, and the lead wire 13 through the upper clamping plate 8. It constitutes a part of the electric path connected to the terminal 5.

With this configuration, the double coil spring 15
The capacitor element 3 can be fixed simply by using the . In this case, the coil spring 15 has a double coil spring structure in which the coil springs 15 are wound in opposite directions and concentrically arranged with the same number of turns, so that when current flows through the double coil spring 15, the coil springs are wound in opposite directions. Since the directions are opposite, the directions of the magnetic fields are reversed and cancel each other out, so that almost no inductance is generated in the double coil spring 15. Therefore, when performing communication using a power line carrier wave, the apparent change in the capacitance of the coupling capacitor section 4 can be almost eliminated, and the characteristics of the power line carrier coupling filter can be prevented from being significantly affected. .

[Effect of idea]

As explained above, according to the present invention, by using a non-inductively wound double coil spring,
It is possible to provide a capacitor-type voltage transformer with excellent high-frequency characteristics in which the inductance of the coupling capacitor portion is suppressed. Furthermore, since there is no connection of connection lead wires, an inexpensive and efficient capacitor type voltage transformer can be provided without complicating assembly.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view showing a conventional capacitor type potential transformer, and FIG. 2 is a partially cutaway sectional view showing an embodiment of the capacitor type potential transformer according to the present invention. DESCRIPTION OF SYMBOLS 1...Transformer part, 2...Insulator tube, 3...Capacitor element, 4, 14...Coupling capacitor part, 5...
...Terminal, 7...Head cap, 8...Tightening plate, 1
0...Insulator tube cover, 11, 15...Coil spring.

Claims (1)

[Scope of utility model registration request] A large number of capacitor elements are stacked and then clamped from below by a clamping plate and housed in an insulator tube, and the upper clamping plate electrically connected to the electrode of the uppermost capacitor element and the upper part of the insulator tube are provided. In the coupling capacitor part, the capacitor element is fixed in the insulator tube by inserting an elastic body between the insulator cover electrically connected to the line terminal, and the elastic body is wound in opposite directions to each other. A capacitor-type meter comprising a double coil spring in which two coil springs having the same number of windings are arranged concentrically, and the double coil spring serves as an electrical circuit connecting the upper clamping plate and the insulating tube cover. transformer.