JPH0933603A - Measuring apparatus for space charge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring apparatus, for a space charge, by which a destructive test can be made while the space charge of a sample to be measured is being measured. SOLUTION: A measuring apparatus for a space charge is composed of an electrode 1, on one side, which is installed on a sample S to be measured and to which a pulse electric charge or a DC or AC electric charge can be applied properly, of a heat-resistant-resin cylindrical cell 4 in which the electrode 1 and the sample S to be measured are housed, of an electrode 5, on the other side, which is installed on the side opposite to the electrode 1, on one side, under the sample S, to be measured, of the cylindrical cell 4, of a piezoelectric element 6 which is installed additionally at the electrode 5 on the other side and of an insulating oil 7 which is filled into the cylindrical cell 4. By the measuring apparatus, the pulse electric charge or the DC or AC electric charge can be applied properly to the electrode 1 on one side, and the electrode 1 on one side is housed in the cylindrical cell 4 filled with the insulating oil 7. As a result, while the space charge of the sample S to be measured is being measured, the generation of a creeping discharge or the like is suppressed effectively, and a destructive test can be made.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a space charge measuring apparatus capable of performing a destructive test while measuring a space charge of a sample to be measured.

[0002]

2. Description of the Related Art Conventionally, polyethylene sheets (films) used for electric wires and cables are
The space charge in the sheet (insulator) is measured or a destructive test is performed.

[0003]

However, up to now, no method has been proposed for simultaneously measuring the space charge and performing the destructive test on the same polyethylene sheet.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional circumstances, and its characteristic means (configuration) is installed on a sample to be measured, and pulse charge and One electrode that can be appropriately applied with a DC or AC electric charge, a tubular cell of heat-resistant resin that accommodates the one electrode and the sample to be measured, and the sample to be measured under the tubular cell. In the space charge measuring device, the other electrode is provided on the opposite side of the one electrode, the piezoelectric element attached to the other electrode, and the insulating oil filled in the cylindrical cell.

[0005]

1 shows an embodiment of a space charge measuring apparatus according to the present invention. In the figure, reference numeral 1 is one electrode (in-cell electrode) which is installed on the sample S to be measured so that the pulse charge from the pulse generator 2 and the DC or AC charge from the DC or AC power supply 3 can be appropriately applied. ) 4 is a cylindrical cell made of a heat-resistant resin such as Bakelite in which the one electrode 1 and the sample S to be measured are housed, and 5 is one of the above-mentioned one of the cylindrical cells 4 below the sample S to be measured. The other electrode (external electrode) installed on the opposite side of the electrode 1, 6 is a piezoelectric element made of PVDF or the like attached to the other electrode 5, and 7 is made of silicon oil filled in the cylindrical cell 4 or the like. Insulating oil, 8 is a cap made of a heat-resistant resin such as Bakelite, which covers the one electrode 1 and the sample S to be measured in the tubular cell 4, 9 is a vibration absorber attached to the piezoelectric element 6, 10 amplifies the signal from the piezoelectric element 6 Because of an amplifier, an oscilloscope and the like digital storage system for displaying a 11 measurements, 12 process such as measurement signals, control, computer for performing such recording, R _1, R ₂ resistors, C is a capacitor.

With this configuration, in the present measuring apparatus, while the pulse charge from the pulse generator 2 is being applied, the DC or AC charge from the DC or AC power source 3 can be simultaneously applied, and the applied voltage Is raised, the measured sample S
Can also lead to dielectric breakdown. In other words, it becomes possible to measure the space charge under the application of DC or AC charges, and also to measure the space charge immediately before the dielectric breakdown. Of course, it is also possible to perform only the charge of the pulse charge to measure the space charge, and further, only to apply the DC or AC charge to perform only the dielectric breakdown. At the time of such a dielectric breakdown test, in the case of the present measuring device, since the cylindrical cell 4 is filled with the insulating oil 7 such as silicon oil, creeping discharge or the like can be effectively suppressed.

FIG. 2 shows another embodiment of the space charge measuring device according to the present invention. In this device, the sample S to be measured is heated in the space charge measurement or the dielectric breakdown test. The heating means 13 such as an electric heater is provided on the bottom side of the tubular cell 4 so that the heating can be performed in this state. This is because when the sample S to be measured is a polyethylene sheet or the like used for electric wires or cables, the sheet is placed in a heated state due to the heat generated by the electric wires or cables when troubles such as insulation breakdown occur. In many cases, the measurement can be performed under heating. This allows more realistic measurements and destructive tests.

[0008]

As is apparent from the above description, according to the space charge measuring apparatus of the present invention, it is possible to appropriately apply a pulse charge or a direct current or an alternating current charge to one electrode, and at the same time, to the one electrode side. Since it is housed in a cylindrical cell filled with insulating oil, it is possible to perform a destructive test while effectively suppressing the occurrence of creeping discharge while measuring the space charge of the sample to be measured. . If a heating means is also provided, it is possible to measure the space charge and to perform a destructive test in the event of a trouble such as insulation breakdown of an actual wire or cable.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing one embodiment of a space charge measuring device according to the present invention.

FIG. 2 is a vertical sectional view showing another embodiment of the space charge measuring apparatus according to the present invention.

[Explanation of symbols]

 1 One Electrode (Intra-Cell Electrode) 2 Pulse Generator 3 DC / AC Power Supply 4 Cylindrical Cell 5 Other Electrode (External Electrode) 6 Piezoelectric Element 7 Insulating Oil 8 Cap 9 Vibration Absorber 13 Heating Means S Sample to be Measured

Claims (1)

[Claims] 1. An electrode provided on a sample to be measured so that a pulse charge or a DC or AC charge can be appropriately applied, and heat resistance in which the one electrode and the sample to be measured are stored. A tubular cell made of resin, another electrode placed on the opposite side of the one electrode under the sample to be measured of the tubular cell, a piezoelectric element attached to the other electrode, and the tubular cell A space charge measuring device, characterized in that the space charge measuring device comprises an insulating oil filled inside.