JPH0754994Y2 - Gas-filled dry condenser - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-filled dry type capacitor in which an insulating material interposed between a capacitor terminal and a case is improved.

[0002]

2. Description of the Related Art Power capacitors are mainly oil-filled capacitors that are impregnated with insulating oil by forming a unit of a single element or a plurality of elements in which a dielectric and an electrode foil or a dielectric having an evaporated electrode are wound. However, recently, for the purpose of nonflammability, a gas filled dry type capacitor filled with an insulating gas instead of the insulating oil is being replaced. In the case of oil-filled capacitors, the withstand voltage performance of the insulating oil is high even when the element or unit is broken, and there is no particular problem, but in the case of gas insulation, the gas density may be low and there is a possibility of ground fault, When trying to protect this, it was necessary to protect a pressure switch or the like that responds with high sensitivity at low pressure.

[0003]

When the capacitor element or unit is destroyed, gas is generated due to the decomposition of the dielectric, and if the electrode dielectric is a metallized film, a conductive eluate is generated when the current is further applied. , Grow up. In the case of a gas-insulated capacitor, when such conductive eluate is generated, the gas density may be low, and if it contacts the case, a ground fault occurs, the electric circuit is interrupted, and the damage due to a power failure is great. In order to prevent this, a protection method is generally used by using a pressure switch, but it is necessary to select a switch that responds to low pressure changes because the signal must be taken out before a ground fault occurs. There was, and it was practically difficult.

[0004]

Means for Solving the Problems The present invention has solved the above-mentioned problems, and is a gas-filled dry type capacitor in which a capacitor element wound with a metallized polypropylene film or a capacitor element unit is housed in a metal case.
A gas-filled dry capacitor in which a mica resin laminated plate 4 formed of an epoxy resin or a silicon resin having a resin component of 4 to 20% by weight is interposed between a capacitor element or a capacitor element unit 3 and a metal case 2. .

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. FIG. 1 is a front sectional view of a gas-filled dry type capacitor, FIG. 2 is a plan view of the inside of a gas-filled dry type capacitor case, 1 is a terminal, 2 is a metal case, 3 is a capacitor unit,
Reference numeral 4 denotes a mica resin laminated plate arranged on the inner bottom surface and the inner side surface of the metal case 2.

A metallized polypropylene film is used as an electrode dielectric, and a conductive eluate generated when the capacitor element or unit housed in the metal case 2 is broken,
Various materials were tested to ensure the insulation performance between the terminal cases, and the change in capacitance was measured in the continuous durability test. The method for testing the insulation performance between the terminal cases is as follows. First, an electrode and an element formed by winding a metallized polypropylene film as a dielectric are used to form a capacitor unit 3
After removing moisture by sufficient vacuum drying, the gas-filled dry type capacitor filled with SF ₆ gas is destroyed by overvoltage application, and then the applied voltage is returned to the rated voltage, and the capacitor element is subsequently destroyed. The pressure was measured when the insulation performance between the terminal cases was lost. The results are shown in Table 1. The materials listed in the material column of Table 1 were tested by interposing them between the capacitor unit 3 and the metal case 2.

[0007]

[Table 1]

The gas filled dry type capacitor used as a test sample has a rating of 3φ 60 Hz 6.6 kV 100 kVA. Before the test, the SF ₆ gas filling pressure was 0 kgf /
cm ² gauge pressure was used. The rate of change in capacity indicates the ratio of the capacity value after continuously applying a voltage 1.1 times the rated voltage at 50 ° C for 1000 hours to the initial value before the test.

As a result, the insulating material between the terminal cases is PV.
In the case of C or polypropylene, the content of water in the material is small, so the capacity decrease in the continuous durability test is small and good, but it is low because it deteriorates due to elution when the element is destroyed and the original insulation performance is lost. Dielectric breakdown due to pressure. On the other hand, in the case of a phenol resin laminate, a mica epoxy resin laminate, and a mica silicone resin laminate, the pressure to cause a dielectric breakdown between terminal cases is high. There is little decrease and it is good.

In the above-mentioned embodiment, when the resin component content of the mica resin laminate exceeds 20% by weight, the heat resistance is lowered, and the conductive elution causes conduction between the terminal cases and the pressure switch does not operate. . If the content of the resin component is less than 3% by weight, the moldability of the laminate will be poor.

[0011]

[Effects of the Invention] As described above, in a dry capacitor in which an element or unit in which a metallized polypropylene film is wound around an electrode and a dielectric is housed in a metal case, a mica-epoxy resin laminated plate or mica-silicon resin is used for insulation between the elements or units. A gas-filled dry capacitor filled with SF ₆ gas with a laminated plate intervening causes the capacitor element to reach the end of its service life and break down for a long time, resulting in high pressure and dielectric breakdown between the terminal cases. It is possible to obtain a capacitor that is easy to protect, economical, and highly safe.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of a gas-filled dry type capacitor of the present invention.

FIG. 2 is a plan view of the inside of a capacitor of one embodiment of the gas filled dry type capacitor of the present invention.

[Explanation of symbols]

 1 terminal 2 metal case 3 capacitor element or capacitor element unit 4 mica resin laminated board

 ─────────────────────────────────────────────────── --Continued from the front page Examiner Shinichi Yamazaki (56) References JP 62-238680 (JP, A) JP 58-81692 (JP, A) JP 63-264337 (JP, A) Actual Kaihei 2-56428 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A gas-filled dry capacitor in which a capacitor element or a capacitor element unit wound with a metallized polypropylene film is housed in a metal case, the capacitor element or the capacitor element unit (3).
A gas-filled dry capacitor in which a mica resin laminated plate (4) made of an epoxy resin or a silicone resin having a resin component amount of 4 to 20% by weight is interposed between the metal case (2) and the metal case (2).