JPH0646209B2 - Partial discharge measuring device - Google Patents

Description

TECHNICAL FIELD The present invention measures a partial discharge generated in a gas-insulated electric device in which a high-potential conductor is supported by an insulator in a ground metal container in which an insulating gas is sealed. The present invention relates to a partial discharge measuring device.

[Conventional technology]

FIG. 3 is a side cross-sectional view of a gas-insulated electric device to which a conventional partial discharge measuring device is connected. A high-potential conductor (3) is placed in a metal container (2) filled with an insulating gas (1). Are supported by insulators (4). The outer wall surface of the metal container (2) is grounded through the primary winding of the transformer (5). The secondary winding of the transformer (5) is connected between the partial discharge measuring device (6) for detecting partial discharge occurring in the gas insulated electric device and the ground.

FIG. 4 is mainly an equivalent circuit diagram of the gas-insulated electric device, and the total capacitance (C _T ) of the gas-insulated electric device is
For example, the first capacitance (Cg) in the space around the protrusion (7) in the high potential conductor (3) and the first capacitance (Cg) between the metal container and the high potential conductor (3) are removed. Between the second capacitor (Cb) and the metal container (2) and the high-potential conductor (3) via an insulator (4) other than the first capacitor (Cg) and the second capacitor (Cb), for example. And a third capacitor (Cm) including the capacitor.
The first capacitor (Cg) and the second capacitor (Cb) are connected in series, and the third capacitor (Cg) is connected in series.
(Cm) is in parallel with these capacitances (Cg) and (Cb). The high potential conductor (3) is a high voltage power source (8).
It is connected to the.

Next, the operation of the conventional partial discharge measuring device having the above configuration will be described. When the potential of the high-potential conductor (3) rises and a partial discharge occurs from the protrusions (7) on the conductor surface and adhered foreign matter (9) such as dust and dust, the space around the protrusions (7) is ionized and becomes a plasma state. Since the surrounding space loses the insulating property and becomes conductive, the first capacitor (Cg) is short-circuited and its value becomes equivalently zero. As a result, the value of the total capacitance (C _T ) changes and the current flowing through the gas-insulated electrical device also changes. This current pulse flows to the ground through the transformer (5), which is detected by the partial discharge measuring device (6).

[Problems to be solved by the invention]

Since the conventional partial discharge measuring device (6) as described above detects the current pulse flowing from the high voltage power supply (8) to the ground through the gas insulated electrical device and the transformer (5), the gas insulated electrical device is detected. The problem was that the device had to be isolated from the ground. In addition, since external electrical noise flows to the ground through the metal container (2) and the deformer (5), there is a problem that the measurement sensitivity of the partial discharge measuring device (6) becomes poor in the field such as a substation. It was

The present invention has been made in order to solve such a problem, and does not insulate the gas-insulated electric device from the ground and is not affected by external electric noise, and adheres foreign matter on the surface of the high-potential conductor. An object of the present invention is to obtain a partial discharge measuring device capable of easily detecting partial discharge caused by protrusions and the like.

[Means for solving problems]

A partial discharge measuring apparatus according to the present invention detects a flow rate of an insulating gas generated by a partial discharge generated in a gas-insulated electric device, and a flow rate of the insulating gas by an electric signal from the gas flow rate detecting element. And a gas flow rate display unit for displaying.

[Work]

In this invention, when partial discharge occurs in the gas-insulated electric device due to protrusions on the surface of the high-potential conductor, adhered foreign matter, etc., a flow velocity is generated in the insulating gas in the metal container, The flow velocity detection element detects the signal, and the signal is transmitted to the gas flow velocity display unit.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing an embodiment of the present invention.
(1), (3), (4), (7) and (9) are the same as in FIG.

In the figure, a sealed terminal (10) is airtightly attached to the grounded metal container (2A). A hot-wire type gas flow velocity detecting element (11) (hereinafter abbreviated as gas flow velocity detecting element) for detecting the flow velocity of the insulating gas (1) in the grounded metal container (2A) is connected to one end of the sealed terminal (10). Has been done. Gas flow velocity detector
An electric field relaxation shield (12) for preventing the electric field from being concentrated by the gas flow velocity detecting element (11) is provided around the area (11). At the other end of the sealed terminal (10), a gas flow velocity detecting element (1
A gas flow rate display section (13) for displaying the flow rate of the insulating gas (1) by an electric signal from 1) is connected.

Next, the principle of flow velocity generation of the insulating gas (1) generated in the grounded metal container (2A) by partial discharge by the protrusion (7) on the surface of the high potential conductor (3) will be described with reference to FIG. When the potential of the high-potential conductor (3) rises, the insulating gas (1) around the protrusions (7) becomes cations.
It is ionized by (14) and anions (15). At this time, the high potential conductor of the positive ions (14) and the negative ions (15)
Ions of the opposite polarity of (3) are attracted to the high potential conductor (3) side, and ions of the same polarity as the high potential conductor (3) repel and head toward the metal container (2) side. Ions facing the metal container (2) side are grounded non-ionized neutral molecules on the metal container (2) side.
Collides with (16) and gives kinetic energy to the neutral molecule (16). In this way, a large amount of cations around the protrusions (7)
When (14) and the anion (15) are supplied, a large amount of ions collide with the neutral molecule (16) in proportion thereto, and a large amount of kinetic energy is given to the neutral molecule (16). ) Moves. In other words, the insulating gas in the grounded metal container (2A)
The gas flow velocity of (1) occurs.

The gas flow velocity of the insulating gas (1) generated as described above is detected by the gas flow velocity detecting element (11). The electric signal generated by the gas flow velocity detecting element (11) is displayed on the gas flow velocity display unit.
It is transmitted to (13) and the occurrence and magnitude of partial discharge in the gas insulated electric device are displayed.

The gas flow velocity detecting element is not limited to the hot wire type, but may be another flow velocity detecting element.

〔The invention's effect〕

As described above, the partial discharge measuring device of the present invention,
The insulating gas generates a flow velocity due to the partial discharge generated by the protrusions of the high-potential conductor, the adhered foreign matter, etc., and this is configured to be detected by the gas flow velocity detection element provided inside the metal container. , It is not necessary to install a transformer for measuring partial discharge between the ground and the metal container, and therefore it is not necessary to insulate the metal container from the ground, and the partial discharge can be performed easily without being affected by external electrical noise. Can be detected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view of a gas-insulated electric device to which an embodiment of the present invention is applied, FIG. 2 is a principle diagram of flow velocity of insulating gas in a metal container, and FIG. FIG. 4 is a side sectional view of a gas-insulated electric device to which a conventional partial discharge measuring device is connected, and FIG. 4 is a diagram mainly showing an equivalent circuit of the gas-insulated electric device. (1) …… Insulating gas, (2A) …… Ground metal container, (3) …… High-potential conductor, (11) …… Gas flow velocity detection element, (13) …… Gas flow velocity display. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A grounded metal container in which an insulating gas is sealed and a high-potential conductor provided in the grounded metal container. The gas-insulated electric device is provided inside the grounded metal container and is provided in the gas-insulated electric device. A gas flow velocity detecting element for detecting a flow velocity of the insulating gas generated by the generated partial discharge, and an electric signal from the gas flow velocity detecting element provided outside the grounded metal container to display the flow velocity of the insulating gas. And a gas flow rate display section for measuring the partial discharge. 2. The partial discharge measuring apparatus according to claim 1, wherein the gas flow velocity detecting element is a hot wire type gas flow velocity detecting element.