JPH0346576A - Device and method for detecting partial discharge of winding - Google Patents

Abstract

PURPOSE:To discharge the partial discharge by applying a pulse voltage to a winding,detecting an elastic wave by an AE sensor and also detecting a strain of the elastic wave caused by a space charge generated by the partial discharge in a winding body. CONSTITUTION:A winding body 2 consisting of an iron core 1 and a multiple cylindrical winding consists of a low voltage winding 3, a high voltage winding 4, a low voltage lead wire 5 and a high voltage lead wire 6. Also, it is constituted of a pulse generating means 7, an AE (acoustic emission) sensor 8 which is placed in the outside peripheral part of the winding body 2 and movable to an arbitrary position, an amplifier 9 and an observing device 10. In this state, when a square wave of several KHz is applied to the winding 4 from the means 7 in a state that a power source of the windings 3,4 is detached, an elastic wave is generated in the winding body 2, therefore, it is detected, while moving the sensor 8. In the part A in which the partial discharge is generated,the elastic wave is strained since a space charge is accumulated, therefore, by detecting it and observing this strain by the device 10, the partial discharge can be detected.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a winding partial discharge detection device and its detection method for detecting partial discharge occurring in the winding of a transformer, etc. Regarding.

(Prior Art) Organic materials are used in the windings of transformers and the like, and these organic materials tend to deteriorate due to partial discharge or arc discharge. For this reason, although transformers and the like are designed to prevent partial discharges from occurring in the windings as much as possible, on rare occasions partial discharges may occur, and when this occurs, it is necessary to promptly detect it. There is.

As an example of a configuration for detecting partial discharge occurring in a winding,
Conventionally, there is a method disclosed in Japanese Patent Application Laid-Open No. 58-80512. In this configuration, a current pulse associated with partial discharge and a sound associated with partial discharge are detected, and partial discharge is detected based on these two detection signals.

(Problem to be Solved by the Invention) However, when detecting partial discharge occurring inside the winding of a transformer, even if the above conventional configuration is directly applied, it is difficult to detect the sound accompanying partial discharge. The drawback was that it was difficult to detect.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a winding partial discharge detection device and a detection method thereof, which can detect partial discharge occurring inside the winding and can easily detect the partial discharge.

[Configuration of the Invention (Means for Solving the Problems) The winding partial discharge detection device of the present invention includes a pulse output means for applying a pulse voltage to the winding, and a pulse output means disposed on the outer periphery of the winding body. All AE sensors detect elastic waves generated in the winding body by application of a pulse voltage, and the elastic waves are caused by space charges generated in the winding body by partial discharge based on detection signals from all the AE sensors. The feature is that the partial discharge is detected by detecting the distortion of the partial discharge.

The method for detecting partial discharge in a winding according to the present invention includes applying a pulse voltage to the winding from a pulse output means, and applying a pulse voltage to the winding from an AE sensor disposed on the outer periphery of the winding. The partial discharge is detected by detecting the generated elastic wave and detecting the distortion of the elastic wave caused by the space charge generated by the partial discharge in the winding body based on the detection signals of all the AE sensors. It has the following characteristics.

(Function) For example, within the winding of a transformer, if there are numerically voids or the like within the winding, the electric field will concentrate and a corona will occur. When a corona discharge, which is a partial discharge, occurs, a space charge is generated and accumulated in the highly insulating material of the winding, and the space charge enhances the corona discharge. Here, the generated space charge has the property of remaining even after the application of voltage to the winding is stopped. In other words, even after the voltage application is stopped, by detecting the space charge, it is possible to detect that a corona discharge, that is, a partial discharge has occurred.

On the other hand, since the space charge generated in the insulating material has a large residual energy, it remains in the place where it is generated for a long time. Also,
Since the above-mentioned space charge is in an energetically unstable state, the portion where the space charge portion is generated also has a high local density at the molecular level. When an elastic wave is applied to the winding body in such a state, the elastic wave becomes distorted due to the partially increased density at the molecular level, that is, due to the space charge. Therefore, partial discharge can be detected by detecting such distortion of elastic waves. The present invention has been made with attention to such circumstances.

That is, according to the above means, a pulse voltage is applied to the winding of the transformer to generate an elastic wave in the winding, and the elastic wave is detected by the AE sensor disposed on the outer periphery of the winding. .

As a result, if a space charge is generated in the winding body due to partial discharge, the distortion of the elastic wave is detected based on the detection signals of all the AE sensors, thereby detecting the partial discharge.

(Example) Hereinafter, an example in which the present invention is applied to a transformer will be described with reference to the drawings.

First, in FIGS. 1 and 2, a winding body 2.2 (two shown) consisting of, for example, multiple cylindrical windings is wound around an iron core 1. As shown in FIG. This winding body 2 is composed of a low voltage winding 3 and a high voltage winding 4. A low voltage lead wire 5.5 is led out from the low voltage winding 3, and high voltage lead wires 6, 6 are led out from the high voltage winding 4. An insulating member is provided between the layers and at the ends of the low voltage winding 3, and the low voltage winding 3 and the iron core 1
An insulating member is provided between the two. An insulating member is also provided between the layers and at the ends of the high voltage winding 4, and an insulating member is provided between the low voltage winding 3 and the high voltage winding 4.
An insulating member is provided on the outer shell. This winding body 2 is constructed of a resin mold type impregnated with resin.

Now, the pulse generating means 7 is adapted to apply a pulse voltage, for example, a rectangular wave of several KHz, to the high voltage winding 4 via its high voltage lead wires 6, 6. Then, an AE sensor 8 (Acoustic
The EllIssion sensor) is movable to any position on the outer periphery of the winding body 2. This AE sensor 8
detects elastic waves generated in the winding body 2 by application of a pulse voltage. A detection signal output from the AE sensor 8 is amplified by an amplifier 9 and then given to an observation device 10 consisting of a preamplifier, a main amplifier, and an oscilloscope.

Next, the operation of the above configuration will be explained with reference to FIG. 3 as well.

In the winding body 2 which is a multiple cylindrical winding, voltage is often applied from the outer circumferential side and the potential is relatively low on the inner circumferential side. Further, since the tap winding is provided on the outer circumferential side of the winding body 2, the potential is partially high, and partial discharge is likely to occur in the interlayer direction.

Assume now that, as shown in FIG. 2, a void or the like has occurred in a portion A of the high-voltage winding 4 on the outer peripheral side of the winding body 2 for some reason, and a partial discharge has occurred in the portion A. To detect a partial discharge in such a case, first, with the power supply disconnected from the windings 3 and 4, a pulse generator 7 connects the high voltage winding 4 via the high voltage lead wires 6 and 6. Apply a KHz square wave.

As a result, elastic waves are generated in the winding body 2. After this, AE
The AE sensor 8 detects elastic waves generated in the winding body 2 while appropriately moving the sensor 8 in the vertical and horizontal directions around the outer circumference of the winding body 2 . In this case, the area A where the partial discharge occurred
Since the space charge generated by the partial discharge is accumulated in the region A, the elastic wave is distorted at the region A by the space charge. Therefore, when the AE sensor 8 is moved to detect an elastic wave at the part A, the detection signal output from the AE sensor 8 is distorted as shown in FIG. 3. Therefore, by observing this distortion with the observation device 10, partial discharge can be detected. In this case, the pulse generator 7 applies a pulse voltage to the winding 4, and the AE sensor 8 only detects the elastic waves generated in the winding 2, so the configuration is simple and partial discharge can be easily detected. can be done. Further, in the embodiment described above, the position where the partial discharge has occurred can be specified based on the position of the AE sensor 8 at the time when the distortion of the elastic wave is detected. Furthermore, since partial discharge is detected with the power source disconnected from the windings 3 and 4, a large-scale insulation structure or the like may be unnecessary.

In the above embodiment, the present invention is applied to the windings 3 and 4 of a transformer, but it may be applied to the windings of a motor or the like instead. Further, in the above embodiment, a rectangular wave of several KHz is applied from the pulse generating means 7 to the high voltage winding 4 with the power supply disconnected from the winding 3.4, but instead of this, A rectangular wave of several KHz may be superimposed on the power supply voltage and applied to the high voltage winding from the pulse generating means while the power supply remains connected to the winding. In this case, it is necessary to provide the AE sensor with an insulating structure that can withstand the above power supply voltage.

[Effects of the Invention] As is clear from the above description, the present invention applies a pulse voltage to the winding from a pulse output means, and also applies the pulse voltage by an AE sensor disposed on the outer periphery of the winding. Since the configuration is such that elastic waves generated in the winding body are detected and partial discharges are detected based on the detection signal from the Al sensor, partial discharges occurring inside the windings can be detected and easily detected. It has the excellent effect of being able to

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a perspective view, FIG. 2 is a vertical sectional view, and FIG. 3 is a diagram showing the waveform of a detection signal output from an AE sensor. In the drawings, 2 is a winding body, 3 is a low voltage winding (winding), 4 is a high voltage winding (winding), 7 is a pulse generating means, and 8 is an AE sensor.

Claims (2)

[Claims] 1. comprising a pulse output means for applying a pulse voltage to the winding; and an AE sensor disposed on the outer periphery of the winding body to detect elastic waves generated in the winding body by application of the pulse voltage; A partial discharge detection device for a winding, characterized in that the partial discharge is detected by detecting distortion of the elastic wave caused by a space charge generated in the winding body by partial discharge based on a signal. 2. A pulse voltage is applied to the winding from a pulse output means, and an AE sensor disposed on the outer periphery of the winding body detects an elastic wave generated in the winding body by the application of the pulse voltage, and detection from the AE sensor is performed. A method for detecting partial discharge in a winding, characterized in that the partial discharge is detected by detecting distortion of the elastic wave caused by a space charge generated in the winding body by partial discharge based on a signal.