JPH0468852B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a corona detection device for monitoring insulation deterioration during operation in a high-pressure rotating machine.

Conventionally, in order to detect corona discharge generated from the insulating layer during operation, a detection coupling capacitor was installed at the high-voltage terminal, a corona current flowing through the ground wire was detected, or an electrode was installed at the coil end. method is known.

However, such a detection device is inferior in terms of safety, reliability, or detection sensitivity, and further has problems such as a narrow detection range and only partial detection ability.

This invention eliminates the drawbacks of the conventional device, and the detection circuit is isolated from the high voltage circuit, providing high sensitivity and
Furthermore, the present invention aims to provide a detection device capable of detecting the occurrence of corona over a relatively wide range.

This invention utilizes a sensor made of metal material that electrically connects the corona discharge generated in the main insulation between the coil conductor and the low resistance coating film provided on the surface of the main insulation. A corona measuring device is provided between the electrode and the stator coil housed in the slot through a layer spacing piece, and the corona measuring device is connected to the electrode to directly detect the corona.

Sensor electrodes can also be inserted into multiple coils, which further increases sensitivity and detection range.

1 and 2 are cross-sectional views of a high-voltage rotating machine coil to which the present invention is applied. In the figure,
1 is a slot provided in the stator core 2;
A stator coil having a coil conductor 3, a main insulation 4 and a low-resistance coating 5 is housed in two stages with a bottom spacer 6, a spacer 7 under the wedge and a layer spacing piece 8 interposed therebetween, and fixed with a wedge 9. has been done. In addition,
10 is a slip layer.

FIG. 3 shows a first embodiment in which the present invention is applied to the coil shown in FIGS. 1 and 2, in which a sensor electrode 31 made of a metal material is provided between the interlayer spacing piece 8 and the low-resistance coating 5 of one coil. A lead 32 is pulled out from the corona measuring device 33 and connected to the corona measuring device 33.

FIG. 4 shows a second embodiment, in which sensor electrodes 31 are provided on both sides of the layer spacing piece 8, and these are arranged in parallel and connected to a corona measuring device (not shown). In this case, the occurrence of corona discharge can be detected for both coils.

FIG. 5 shows a third embodiment in which the sensor electrode 31 is molded with a low resistance material 52 and is sandwiched between the coils instead of a spacing piece.

Basically, the sensor electrode 31 may be a simple flat plate as shown in FIG.

7 and 8 show different examples of the sensor electrode 31, and in FIG. 7, the electrode 3
1, and in Figure 8, electrode 3.
1 is mesh-shaped to reduce loss due to leakage magnetic flux.

FIG. 9 shows yet another embodiment of the invention. In this case, the low resistance coating film is divided into parts 51 and 52,
The sensor electrode 31 is brought into contact with the portion 52.
In this way, even if the coating portion 51 is in electrical contact with the iron core 2, the coating portion 52 insulated from the iron core 2 makes it possible to detect the occurrence of corona discharge with high sensitivity.

According to the present invention, corona discharge can be detected while a high-voltage rotating machine is in operation, so the deterioration state of insulation can be constantly monitored without stopping the machine, information useful for preventive maintenance can be obtained, and unexpected accidents can be prevented. It can be prevented.

[Brief explanation of the drawing]

1 and 2 are radial and axial sectional views of a high-voltage rotary machine stator coil according to the present invention, FIGS. 3 to 5 are sectional views showing different mounting states of sensor electrodes, and FIG. 6 8 to 8 are plan views illustrating different structures of sensor electrodes, and FIG. 9 is a sectional view showing another embodiment of the present invention. 1... Slot, 2... Stator core, 3... Coil conductor, 4... Main insulation, 5, 51, 52... Low resistance coating film, 6, 7... Spacer, 8... Layer spacing piece, 9...Wedge, 31...Sensor electrode, 33
...Corona measuring device.

Claims (1)

[Claims] 1 A device for detecting corona discharge occurring in the insulating layer of a stationary coil of a high-voltage rotating machine, in which a sensor electrode made of a metal material electrically coupled to a low-resistance coating film housed in the slot. 1. A corona discharge device for a high-voltage rotating machine, characterized in that the stator coils are provided with interlayer spacing pieces interposed therebetween, and a corona measuring device is connected to the electrodes.