JPH04296672A - Abnormality detector for rotary electric machine - Google Patents

Abstract

PURPOSE:To accurately measure the abnormality of a stator coil by measuring the properties of the electric discharge from the signal of the high frequency current induced by means of the partial electric discharge occurring together with the abnormality of a stator coil together with the temperature of the stator coil. CONSTITUTION:When abnormality occurs in a rotary electric machine due to deterioration of a stator coil 3, partial electric discharge occurs, high frequency current flowing, and it is detected by a detector 7 electromagnetically connected to the coil 3, eliminating a low frequency signal used for measuring temperature by means of a filter 11, and only the high frequency signal based on the partial electric discharge is input in a partial electric discharge measuring device 12. The input signal, after unnecessary noise of which is eliminated by the measuring device 12, is analyzed, and the properties of the electric discharge such as the quantity of electric charge, the time of the generation, the frequency of the generation and spectrum are measured. At the same time, the temperature of the coil 3 is detected by the detector 7 and measured by a temperature measuring device 10. The measuring results of the properties of partial electric discharge and the temperature are compared with the abnormality data of an abnormality discriminating circuit 13 to discriminate the presence or absence of abnormality, and are also sent to an interface circuit 16 to be always monitored together with operation records by an electronic computer.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality detection device for a rotating electrical machine that can detect and continuously monitor abnormalities caused by insulation deterioration of stator windings.

0002

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional temperature measuring device for measuring the temperature of a stator winding of a rotating electric machine. A stator core 2 is fixed to a stator frame 1, and a predetermined number of slots 5 are provided at equal intervals in the axial direction on the inner peripheral surface of the core 2, and two upper and lower stator windings 3 are housed in these slots. and is fixed by a wedge 6. Further, a temperature detector 7 for detecting the temperature of the stator winding 3 is inserted between the upper and lower windings in a predetermined slot 5. The temperature detector 7 includes a temperature detection element 8 and a lead wire 9, and is connected to a temperature measuring device 10.

Next, the operation will be explained. Stator winding 3
The temperature of is detected by the temperature detection element 8 and converted into an electrical signal. Next, the electrical signal is inputted to a temperature measuring device 10 through the lead wire 9, and the electrical signal is measured by the temperature measuring device 10 and converted into a temperature.

[0004] Furthermore, as a method for monitoring abnormalities in rotating electric machines,
Conventionally, a coupling capacitor is permanently inserted on the line side of a rotating electrical machine, and high-frequency current due to discharge is detected through this coupling capacitor, and load current is detected from the neutral point of the stator winding or the power line. A device has been proposed that monitors the correlation between these load currents and high-frequency currents.

FIG. 6 is a circuit configuration diagram showing a conventional method for monitoring a rotating electric machine disclosed in, for example, Japanese Patent Laid-Open No. 1-191072. In the figure, reference numeral 19 denotes a rotating electrical machine, for example, an electric motor, and this electric motor 19 has U, V, and W phase windings as stator windings 3. This stator winding 3 includes U, V,
A power supply line 20 of W phase is connected.

A sensor, for example, a high frequency current transformer 18 is connected to the neutral point of the stator winding 3 of the electric motor 19 to extract the load current, which is converted into a digital signal by the A/D converter 21. It is recorded on the recorder 22.

On the other hand, coupling capacitors 23a, 23b, and 23c made of solid capacitors with excellent high frequency characteristics are connected to each of the U, V, and W phases of the power line 20 connected to the stator winding 3, and these capacitors 23a to 23c are connected to each other. A high frequency current based on the discharge is taken out through 23c and applied to the detector 24. Then, the output from the detector 24 is applied to the filter 12 via the switch 17. This filter 12 removes noise from a power source, broadcast waves, electromagnetic induction, and the like. Then, the output that has passed through the filter 12 is given to a partial discharge measuring device 26 via a resistance attenuator 25. Here, the measurement results of the partial discharge measuring device 26 are measured by the oscilloscope 2.
The waveform is observed by 7, and the signal is analyzed by spectrum analyzer 28. In addition, partial discharge measuring device 2
The output from 6 is given to the recorder 22 and recorded together with the above-mentioned load current.

[0008]

Since the conventional temperature measuring device for a rotating electric machine is constructed as described above, it is possible to detect an abnormality accompanied by a rise in temperature of the stator winding. However, there are also abnormalities in the stator windings that are not accompanied by a rise in temperature, such as abnormalities due to deterioration of the main insulating layer, and it is necessary to install a separate device to detect partial discharges that occur due to abnormalities.

[0009] Furthermore, in the conventional method of detecting partial discharge as described above, a high voltage is applied to a capacitor inserted into the line, and the reliability of this capacitor may reduce the reliability of the entire rotating electric machine. .

The present invention has been made to solve the above-mentioned problems, and it is possible to measure the temperature of the stator winding and to detect partial discharges caused by abnormalities in the stator winding with high accuracy. The purpose is to obtain an abnormality detection device for electrical machinery.

[0011]

[Means for Solving the Problems] An abnormality detection device for a rotating electrical machine according to the present invention includes a detector provided adjacent to a stator winding of the rotating electrical machine to detect the temperature of the stator winding, and a detector for detecting the temperature of the stator winding. The device is equipped with a temperature measuring device that converts the signal from the device into temperature, and the high-frequency current that is induced by the partial discharge that occurs due to an abnormality in the stator winding and propagates through the stator winding is detected by the detector. A partial discharge measuring device is provided to measure partial discharge characteristics from the signal of the stator winding, and an abnormality in the stator winding is detected by detecting the partial discharge as well as the temperature of the stator winding.

0012

[Operation] In this invention, in addition to the temperature of the stator winding, a detector detects the high frequency current generated by discharge and propagates through the stator winding, and a partial discharge measuring device measures the partial discharge characteristics. Can continuously monitor abnormalities in electrical equipment. Also,
The detector is provided adjacent to the stator winding and measures the high frequency current near the point where the abnormality occurs, improving detection accuracy.

[0013]

EXAMPLES Example 1 An example of the present invention will be described below with reference to the drawings. Figure 1
2 is a vertical cross-sectional configuration diagram showing the structure of a rotating electric machine according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of an abnormality detection device for the rotating electric machine showing an enlarged stator winding section. A rotating electrical machine is composed of a stator including a stator frame 1, a stator core 2, stator windings 3, and a rotor 4. A stator core 2 is fixed to a stator frame 1, and a predetermined number of slots 5 are provided at equal intervals in the axial direction on the inner peripheral surface of the core 2, and two upper and lower stator windings 3 are housed in these slots. and wedge 6
Fixed by 7 is a detector for detecting the temperature of the stator winding 3 and the high frequency current generated by partial discharge caused by an abnormality in the stator winding 3 and propagating through the stator winding 3; It is inserted between two upper and lower stator windings 3. The detector 7 consists of a temperature detection element 8 such as a search coil and a lead wire 9, and a temperature measuring device 10.
It is connected to the. Furthermore, a filter 11 and a partial discharge measuring device 12 are connected in series to the detector 7 in parallel with the temperature measuring device 10. Reference numeral 13 denotes an abnormality determination circuit to which the outputs of the temperature measuring device 10 and the partial discharge measuring device 12 are transmitted and compared with pre-registered data.If it is determined that there is an abnormality, an alarm signal is sent to the alarm device 14 and the abnormality display device 15. Output. Further, the signal from the abnormality determination circuit 13 is always sent to the interface circuit 16, and is constantly monitored along with the operation record by the computer.

Next, the operation of this embodiment will be explained. A high voltage is generated in the stator winding 3 while the rotating electric machine is operating. When an abnormality occurs in the rotating electric machine due to insulation deterioration of the stator winding 3, partial discharge occurs in the stator winding 3, and a high frequency current flows. Also, depending on the type of abnormality, stator winding 3
temperature may rise. The high frequency current caused by the discharge also propagates to the detector 7 which is electromagnetically coupled to the upper and lower stator windings 3, and is input to the filter 11. Since the partial discharge signal has a high frequency of several kHz or more, the filter 11 removes the low frequency signal used for temperature measurement, and only the high frequency component based on the partial discharge is input to the partial discharge measuring device 12. After removing unnecessary noise, the partial discharge measuring device 12 analyzes the input signal and measures discharge characteristics such as the amount of partial discharge charge, the time of occurrence, the frequency of occurrence, and the spectrum. Simultaneously with the partial discharge characteristic measurement, the temperature of the stator winding 3 is detected by the detector 7 and measured by the temperature measuring device 10. The measurement results of partial discharge characteristics and temperature are output to the abnormality determination circuit 13. The abnormality determination circuit 13 compares the measurement results with pre-registered abnormality data to determine the presence or absence of an abnormality, and the measurement results are sent to the interface circuit 16, where they are constantly monitored along with operation records by a computer. Further, when the abnormality determination circuit 13 determines that there is an abnormality, an alarm signal is output to the alarm device 14 and the abnormality display device 15.

[0015] In this embodiment, the temperature of the stator winding 3 and partial discharge are detected, and abnormalities can be constantly monitored. Further, since the detector 7 is provided between the upper and lower windings and detects the high frequency current based on the abnormality near the point where the abnormality occurs, the detection accuracy can be improved.

Embodiment 2 FIG. 3 is a block diagram of main parts showing an abnormality detection device for a rotating electric machine according to another embodiment of the present invention. In the above embodiment, a case is shown in which the detector 7 is provided with a pair of signal processing circuits, but in this embodiment, as shown in FIG. Switching the connection between each detector 7 and the partial discharge measuring device 12 or the temperature measuring device 10 in a time-sharing manner,
Similar effects can be obtained by measuring the temperature and partial discharge in each detector 7. Note that in this configuration, there is no need to provide each signal processing circuit for each detector, resulting in low cost.

Embodiment 3 FIG. 4 is a block diagram showing an abnormality detection device for a rotating electric machine according to still another embodiment of the present invention. In the first embodiment, a filter 11 was provided to separate the low frequency signal used for temperature measurement and the high frequency signal based on partial discharge, but in this embodiment, a high frequency current transformer 18 was provided, and the It is configured to produce the same effects as the embodiment.

In the above embodiment, the detector 7 is installed between the upper and lower stator windings 3 inside the slot 5 of the stator. Detected at a position adjacent to the stator winding 3 inside the slot 5, such as between the bottom of the slot 5 and the lower part of the stator winding 3, or between the side of the stator winding 3 and the slot 5. Even if the container 7 is installed, the same effect can be obtained.

[0019]

As described above, the abnormality detection device for a rotating electrical machine of the present invention includes a detector that is provided adjacent to the stator winding of the rotating electrical machine and detects the temperature of the stator winding, and a detector for detecting the temperature of the stator winding. A device equipped with a temperature measuring device that converts a signal from a detector into a temperature includes a high frequency wave that is induced by a partial discharge that occurs due to an abnormality in the stator winding detected by the detector and propagates through the stator winding. Since a partial discharge measuring device that measures partial discharge characteristics from a current signal is provided, it is possible to accurately detect partial discharge as well as the temperature of the stator winding, and there is an effect that an abnormality in the stator winding can be detected with high accuracy.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional configuration diagram showing the structure of a rotating electric machine according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an abnormality detection device for a rotating electric machine according to an embodiment of the present invention.

FIG. 3 is a configuration diagram showing an abnormality detection device for a rotating electric machine according to another embodiment of the present invention.

FIG. 4 is a configuration diagram showing an abnormality detection device for a rotating electrical machine according to still another embodiment of the present invention.

FIG. 5 is a configuration diagram showing a conventional rotating electric machine stator winding temperature measuring device.

FIG. 6 is a circuit configuration diagram showing a conventional abnormality monitoring method for a rotating electric machine.

[Explanation of symbols]

1 Stator frame 2 Stator core 3 Stator winding 7 Detector 10 Temperature measuring device 12 Partial discharge measuring device

Claims (1)

[Claims] 1. A rotating electric machine comprising: a detector provided adjacent to a stator winding of a rotating electrical machine; a detector for detecting the temperature of the stator winding; and a temperature measuring device for converting a signal from the detector into temperature. In an abnormality detection device for an electric machine, a part that measures partial discharge characteristics from a signal of a high-frequency current that is induced by a partial discharge that occurs due to an abnormality in the stator winding detected by the detector and propagates in the stator winding. Install a discharge measuring device,
An abnormality detection device for a rotating electric machine, which detects an abnormality in the stator winding by detecting temperature and partial discharge of the stator winding.