JPH04372881A - Estimate and maintenance apparatus - Google Patents

Abstract

PURPOSE:To perform the discrimination of a partial discharge generating factor and the accurate location of a position by dividing one electrode of a sheet like piezoelectric composite material sensor into a plurality of electrodes. CONSTITUTION:Piezoelectric composite sensors 10a, 10b ate attached to the inner surface of a hermetically sealed container 1. Didided conductive rubber electrodes 20 constituted so as to be divided into an mXn matrix form are provided on the side of the container 1 and a conductive rubber electrode 12 is provided on the side of a high voltage conductor 2. The metal foreign matter mixed into the container 1 gets about along the bottom surface of the container 1 by the AC voltage applied to the high voltage conductor 2 and collides with the bottom surface of the container to generate mechanical vibration and partial discharge. These vibration and discharge are positionally changed every hr but, since the piezoelectric composite material sensors 10 are arranged over a wide range, the positions thereof are accurately detected. That is, the signals obtained from a plurality of the sensors 10 arranged in the matrix form are sent to the measuring device provided to the outside of the container and the patterns of the detection signals of said sensors are judged to accurately discriminate an abnormal state.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a predictive maintenance device for detecting the presence or absence of an abnormality in high-voltage electrical equipment, and in particular, to obtain more accurate information about the nature of the abnormality by providing multiple sensor outputs. The present invention relates to a predictive maintenance device that has been improved so that it can perform the following tasks.

0002

2. Description of the Related Art Various high-voltage devices are used in substations, switching stations, etc., and these high-voltage devices are housed inside sealed metal containers. In such cases, the internal state of the device cannot be directly grasped from the outside, so
Internal equipment status is monitored using some means.

[0003] A predictive maintenance system is one of the means for detecting such an abnormality occurring inside a metal container in advance. This device monitors the status of equipment using a plurality of various sensors.

[0004] Among these, detecting partial discharges that occur due to some kind of electrical abnormality is useful because it allows us to know whether there is insulation deterioration, poor electrical connections, or the presence of metal foreign matter inside the equipment. , is extremely important information.

Generally, when a partial discharge occurs, it not only propagates to the surroundings as an electrical signal but also generates mechanical vibrations. Conventionally, partial discharges have been detected using partial discharge detectors that detect electrical signals caused by partial discharges. , acceleration sensors that detect mechanical vibrations, and ultrasonic sensors have been used.

Furthermore, in recent years, attempts have been made to use a piezoelectric composite material sensor in which piezoelectric ceramic fine particles are blended with a polymeric material to form a sheet for detecting partial discharge. Figure 3
shows an example. That is, conductive rubber electrodes 12 are attached to both sides of piezo rubber 11, which is a sensor.

The characteristics of this piezoelectric composite material sensor are as follows:
The frequency characteristics are flat over a wide frequency range from 00 hertz to 1 megahertz, and since the sensor is sheet-shaped and highly elastic, it is extremely easy to install even on containers with complex shapes. be. Therefore, it has the characteristic of being able to detect everything from low-frequency signals such as mechanical vibrations to high-frequency components such as those contained in partial discharges with a single sensor, without being affected by external noise.

[0008]

[Problems to be Solved by the Invention] However, the conventional piezoelectric composite sensor as described above has the following problems to be solved. That is, when a sheet-shaped piezoelectric composite material sensor is attached to a device, the presence or absence of partial discharge or mechanical vibration can be determined with a single sensor, but there is a drawback that the source of the occurrence cannot be identified.

On the other hand, when conventional acceleration sensors and ultrasonic sensors are used, multiple sensors must be installed, and each sensor is large, so the area required for installation becomes large. There were drawbacks. Furthermore, there is a natural limit to the number of sensors that can be attached, and even if a large number of sensors are attached, there is a drawback that the attachment work requires a great deal of time and effort.

The present invention was proposed to solve the problems of the prior art as described above, and its purpose is to provide simple installation, easy identification of the source, and easy detection and detection of abnormalities. An object of the present invention is to provide a highly accurate predictive maintenance device that can accurately determine the content of an abnormality.

[0011]

[Means for Solving the Problems] The present invention comprises forming a piezoelectric composite material into a sheet shape, arranging electrodes on both sides of the piezoelectric composite material sensor, and placing the piezoelectric composite material sensor in a metal container housing high voltage equipment. In a predictive maintenance device that is attached to an inner or outer surface to detect an abnormality, one electrode of the piezoelectric composite material sensor is divided into a matrix, and the outputs obtained from the plurality of divided electrodes are processed as signals. It is characterized by having the following configuration.

0012

[Operation] According to the predictive maintenance device of the present invention, the same effect as a plurality of sensors can be obtained with a single sheet-shaped piezoelectric composite material sensor. Further, by signal processing the outputs of these plurality of sensors, it is possible to accurately specify the location where the abnormality has occurred, and it is also possible to identify the cause of the occurrence of partial discharge.

[0013]

[Embodiment] An embodiment of the present invention will be explained in detail below with reference to FIGS. 1 and 2. Note that the same members as those of the conventional type shown in FIG. 3 are given the same reference numerals, and explanations thereof will be omitted.

In this embodiment, as shown in FIG.
One electrode of the piezoelectric composite material sensor is configured by being divided into an m×n matrix (hereinafter referred to as divided conductor rubber electrode 20). Note that the other electrode is constituted by a single conductive rubber electrode 12 as in the conventional case.

Further, FIG. 2 shows a case where the piezoelectric composite material sensor 10 configured as described above is applied to a gas insulated bus bar. That is, a high voltage conductor 2 is disposed in a closed container 1 supported by an insulating spacer 4, and the container is filled with an insulating gas 3 such as SF6 gas. Furthermore, piezoelectric composite material sensors 10a and 10b according to the present invention are attached to the inner surface of the closed container 1, and the structure is such that the detection signals thereof can be taken out to the outside of the container.

Note that the piezoelectric composite material sensors 10a, 10
b is a divided conductor rubber electrode 2 provided on one side of the electrode.
0 is attached to the container side, and the conductive rubber electrode 12 provided on the other side is attached to the high voltage conductor side.

The predictive maintenance device of this embodiment having such a configuration operates as follows. That is, the piezoelectric composite material sensors 10a, 10 attached to the inner surface of the closed container 1
Abnormalities can be identified by sending signals obtained from multiple sensors arranged in a matrix in b to a measuring device (not shown) installed outside the container and determining the pattern of the detected signals. becomes.

Furthermore, since the piezoelectric composite sensor 10 is in the form of a thin sheet, it can be installed inside a container with little external noise. Furthermore, since it is sheet-like, it has excellent workability and can be attached closely to the inner surface of the metal container in accordance with the curvature of the container. Therefore, it is easy to install it at a location where abnormal signals can be easily detected, and since it has excellent adhesion to the inner surface of the metal container, there is also the advantage that the attenuation of the detection signal is small.

Furthermore, since it does not have a resonant structure and can be applied over a wide range of frequencies, it has a simpler structure than conventional resonant piezoelectric sensors, and can detect both partial discharge and metal foreign object vibration with one type of sensor. Since this is possible, there is no need to install a plurality of sensors as in the past, and costs can be reduced.

[0020] Next, as a specific example, a case will be described in which a metal foreign substance gets mixed into the inside of a gas insulated device using SF6 gas. In other words, metal foreign matter mixed inside the container is
The AC voltage applied to the high voltage conductor 2 causes the airtight container 1 to
moving around on the bottom of the. In such a state, when a foreign metal object collides with the bottom of the container, mechanical vibration and partial discharge occur. This mechanical vibration and partial discharge are detected by the piezoelectric composite material sensor 10, but even if the position of the metal foreign object changes from time to time, since the piezoelectric composite material sensor 10 is installed in a sheet shape over a wide area,
Its position can be accurately detected by multiple sensors arranged in a matrix.

[0021] This makes it possible to distinguish signals generated from a fixed position, such as a partial discharge signal generated from an insulator, and it is possible to more accurately determine the presence or absence of metal foreign matter. Furthermore, by calculating the output of each element, the position of the partial discharge source can be specified. Furthermore, as shown in FIG. 2, when the piezoelectric composite sensor 10 is attached to the inner surface of the container, by placing the conductive rubber electrode 12 on the high voltage conductor 2 side, the electric field generated by the high voltage conductor 2 can be transferred to the piezoelectric composite material sensor 10. 11. That is, it is also possible to improve the S/N ratio of the signal.

As described above, according to this embodiment, by dividing one electrode of the sheet-shaped piezoelectric composite material sensor into a plurality of parts, it becomes possible to identify the cause of partial discharge occurrence and to evaluate the position. This makes it possible to provide a predictive maintenance device that can more accurately identify the nature of the abnormality.

It should be noted that the present invention is not limited to the embodiments described above, and similar effects can be obtained even if a piezoelectric composite material sensor is attached to the outer surface of the container 1. In addition, increasing the signal line length of the piezoelectric composite material sensor increases external noise, so it is recommended to install a signal processing circuit near the piezoelectric composite material sensor and connect this output to the receiving side using an optical fiber, etc. Conceivable. According to this method, signal processing can be performed with almost no influence from external noise. Furthermore, in signal processing, by combining with a neural network, for example, more accurate pattern recognition can be achieved, and more reliable abnormality diagnosis can be made.

[0024]

[Effects of the Invention] As described above, according to the present invention, one electrode of a piezoelectric composite material sensor is divided into a matrix, and the outputs obtained from the plurality of divided electrodes are subjected to signal processing. With this configuration, it is possible to provide a highly accurate predictive maintenance device that is easy to install, easy to identify the source, and can accurately detect and determine the nature of the abnormality.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a piezoelectric composite material sensor used in the predictive maintenance device of the present invention.

[Fig. 2] A cross-sectional view showing an example in which the predictive maintenance device of the present invention is applied to a gas-insulated bus bar.

[Fig. 3] A perspective view showing an example of a conventional piezoelectric composite material sensor.

[Explanation of symbols]

1...Airtight container 2...High voltage conductor 3...Insulating gas 4...Insulating spacer 10...Piezoelectric composite material sensor 11...Piezo rubber 12...Conductive rubber electrode 20...Divided conductive rubber electrode

Claims (1)

[Claims] Claim 1: A piezoelectric composite material sensor is constructed by forming a piezoelectric composite material into a sheet shape and arranging electrodes on both sides of the sheet, and attaching this to the inner or outer surface of a metal container containing high voltage equipment to detect abnormalities. In predictive maintenance equipment that detects
A predictive maintenance device characterized in that one electrode of the piezoelectric composite material sensor is divided into a matrix, and outputs obtained from the plurality of divided electrodes are subjected to signal processing.