JPS5931289B2 - Abnormality diagnosis device for windings of electrical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical device that detects an abnormality in a winding of an electrical device, such as a winding incorporated in a stator, a rotor, or an armature of a rotating electrical machine, or a defect in the supporting state of the winding. winding abnormality diagnosis device (hereinafter simply referred to as the device as appropriate).

). Hereinafter, for convenience of explanation, a case of a rotating electrical machine will be described as an example of an electrical device.

In recent years, there has been a remarkable increase in the capacity of rotating electric machines, as well as reductions in their size and weight, and the windings of rotating electric machines are being exposed to increasingly severe conditions.

Amidst these trends, coupled with tighter supply and demand for electric power and longer periodic inspection periods, rotating electric machines are required to have even higher reliability. Furthermore, in line with the sluggish economic growth, the capacity of rotating electric machines has been expanded or supplemented over a much longer period of time than before, and the tendency for rotating electric machines to deteriorate is increasing.

For this reason, not only the windings of future large-capacity rotating electric machines, but also
From the viewpoint of confirming the reliability of the windings of conventional machines and preventive maintenance against accidents, it is becoming increasingly important to non-destructively diagnose abnormalities in the windings and poor support conditions. Conventionally,
Diagnosis of abnormalities in the windings of rotating electric machines involves visual inspection, hammering tests, and other methods to determine abnormalities in the windings, and much of this relies on the experience and intuition of the operator.

This force method lacks objective information or materials for determining abnormalities in the windings. In addition, since the quantities of many influencing factors cannot be directly measured, the force method has been used to understand them by replacing them with alternative quantities. For this reason, it may take many years of empirical observation to draw inductive inferences from some data, and it is possible to predict the subsequent state based on the judgment results of data obtained during inspection or understanding the state. There were problems such as there were no such facilities. In order to solve the above problem, this invention causes a known amount of current to flow through the winding to force the winding to vibrate, thereby reducing the sudden change in mechanical force caused by nonlinear vibration or collision vibration of the winding. Detect and
The present invention is intended to provide a winding abnormality diagnosing device that determines an abnormality occurring in the winding or a poor support state of the winding.

An outline of a force method for diagnosing an abnormality in an armature winding of a DC machine will be described below based on an embodiment of the present invention. Figure 1 shows
1 is an embodiment of an abnormality diagnosing device for a winding of a rotating electric machine according to the present invention.

This example shows a method for diagnosing an abnormality in the armature winding of a DC machine. In Fig. 1, 1 is the armature main body, 2 is the armature winding, 3 is the commutator, 4 is the riser that connects the armature winding 2 and the commutator 3, and 5 is the armature winding due to centrifugal force. A glass band is used to prevent the armature winding from being bent and deformed. 6 is the armature winding 2.
, 7 is a pressure equalizing coil, and 8 is a bearing. As shown in FIG. 1, the armature commutator 3 configured in this way is
A power supply device 10 of the device according to the present invention is connected with a lead wire 9. This power supply device 10 is capable of passing an alternating current through the armature winding 2 only for a certain predetermined period. This applied current causes the armature winding 2 to undergo a strong spring motion, and the vibration state of the armature winding 2 at this time is measured and detected by the accelerometer 11 fixed or pressed against the winding. The results are then displayed on an oscilloscope 110, which is a display means. As is clear from this, the power supply device 10 applies current to the armature winding 2, and
It constitutes a vibrating means for forcibly vibrating. still,
For example, a so-called piezoelectric element type accelerometer is used as the accelerometer 11. Next, power supply device 1 of the abnormality diagnosis device according to the present invention.
0, that is, the vibration excitation means will be explained.

FIG. 2 is a configuration diagram showing one embodiment of the power supply device 10,
FIG. 3 shows the output current waveform obtained from this power supply device 10 and the pulse waveform flowing through the counter 18, with the horizontal axis as the time axis. As shown in FIG. 2, this power supply device 10 includes a switch 12, a slider 13, a power transformer 14, a thyristor 15, a gate 16, an ignition control circuit 11, a counter 1
8, a power transformer 19, an ammeter 20, etc. Note that I and O indicate an input terminal and an output terminal, respectively. In this power supply device 10, the amplitude of the current flowing through the armature winding 2 is adjusted by adjusting the slider 13 connected to the primary side of the power transformer 14. Therefore, the slider 13 is nothing but an adjusting means for adjusting the amplitude of the output of the excitation means. The phase of the current at the start of energization is thyristor 1.
5 and an ignition control circuit 17. That is, the thyristor 15 and the ignition control circuit 17 constitute phase angle control means. Point B of the current waveform 21 shown in FIG. 3 indicates the time of application, and the figure shows the case where the current phase is zero at the time of application. However, in general, the closing phase is adjustable from 0 to 18'. The counter 18 has a pulse waveform 22 in FIG.
As shown in , the ignition control circuit 17 is
The number of pulses 23 generated is counted. By this, the number of cycles of the current during the energization period is determined, and when a predetermined number of cycles is reached, the ignition control circuit 1
The generation of pulses at 7 is stopped and the supply of diagnostic current to the armature winding 2 is cut off. This is because when diagnosing the presence or absence of an abnormality, a diagnostic current exceeding the rated current is applied in order to make the windings of the rotating electrical machine more likely to generate forced vibrations, so the period of energization is kept as short as possible to prevent the windings from generating heat. This is because it was intended to prevent Next, a method of diagnosing an abnormality in an armature winding using the abnormality diagnosing device according to the present invention will be explained.

First, the power supply device 10 is connected to the commutator 3 as shown in FIG. Then, the number of cycles of the current flowing through the armature winding 2 is set to a predetermined value. Next, the switch 12 in FIG. 2 is turned on, and the current flowing through the armature winding 2 is measured by the ammeter 20, and the vibration acceleration generated in the armature winding 2 is measured by the accelerometer 11 in FIG. This operation is repeated while adjusting the slider 13 to generate vibrations of an appropriate magnitude in the armature winding 2. Then, a sudden change appearing in the acceleration waveform of the armature winding 2 is detected, and in the DC machine immediately after manufacture, a defect in the support state of the armature winding 2 within the slot is investigated. In addition, for DC machines that have a history of operation, we can detect sudden changes that appear in the acceleration waveform of armature winding 2, and compare the acceleration waveform after operation with the acceleration waveform measured at the time of manufacture to determine whether any sudden changes have occurred in armature winding 2. Check for abnormalities or poor support of the armature winding 2. Next, the principle of diagnosing a winding abnormality using the apparatus according to the present invention will be explained.

Figure 4 shows that there is no abnormality in the armature winding 2, and that the armature winding 2
FIG. 4 is a diagram showing a comparison of an electromagnetic force waveform 24 and an acceleration waveform 25 when the motor is well supported within the slot. As shown in FIG. 4, when the armature winding 2 has no abnormality and is well supported, the armature winding 2 has an electromagnetic force waveform 24
Correspondingly, the acceleration waveform 25 also has a sinusoidal waveform. Note that the electromagnetic force waveform 24 is drawn based on the fact that it is a waveform that is similar in principle to the diagnostic current waveform. FIG. 5 shows a comparison between the electromagnetic force waveform 24 and the acceleration waveform 25 when a board occurs inside the armature winding 2 or when the armature winding 2 is poorly supported inside the slot. This is a diagram.
As shown in Fig. 5, if a board occurs in the armature winding 2 or if the armature winding 2 is poorly supported within the slot, the armature winding 2 will experience nonlinear vibration or collision vibration within the slot. Therefore, in the acceleration waveform 25 on the oscilloscope 110, sudden pulse-like acceleration changes 26 and 26' appear on the fundamental wave corresponding to the electromagnetic force waveform 24. This pulse-like acceleration change 26, 26'' appears every time the armature winding 2 vibrates in the direction of the wedge and the slot bottom force, and after this pulse-like acceleration change 26, 26'0, 2
A high frequency acceleration change 27 of ~3 cycles appears. Therefore, by measuring changes appearing in the acceleration waveform 24 of the armature winding 2, abnormalities in the armature winding 2 or poor support conditions can be detected from the sudden change in the waveform. In the above-mentioned embodiment, a force method was described for detecting an abnormality or poor support state of the armature winding 2 based on sudden changes in the acceleration of the armature winding 2.

A sudden change similar to the acceleration of the armature winding 2 appears in the load and wedge strain caused when the armature winding 2 collides with the wedge or the bottom of the slot. Therefore, it is clear that an abnormality in the armature winding 2 can be detected even by detecting the load or wedge strain. In addition, in the example,
Although the method for diagnosing an abnormality in the armature winding of a DC machine has been described as an example, it can be seen that it is also effective in detecting abnormalities in the windings of other rotating electric machines such as generators and induction motors.

As is clear from its principle, the present invention is applicable not only to rotating electrical machines but also to stationary electrical equipment having windings, such as transformers.

In the embodiment, a case has been described in which the power supply device 10 is configured so that an alternating current is passed through the armature winding 2 by a so-called alternating current power supply. Even when the DC current is energized, as long as the DC current has a predetermined period, abnormality diagnosis can be performed to a certain extent. In this way, in the present invention, an abnormality can be detected by using an excitation means for forcibly vibrating the winding with a current of a predetermined frequency, a detection means for detecting mechanical force based on the forced vibration, and a display means for displaying the detection result. Now that you have configured the diagnostic equipment,
It is possible to non-destructively detect an abnormality in the winding of an electrical device or a poor support state of the winding within the slot.

Therefore, it is possible to diagnose defects in the manufacturing of electrical equipment, defects in the windings after a certain period of operation, and defects in the supporting state of the windings, thereby improving the reliability of electrical equipment. It can also be useful for preventive maintenance of electrical equipment accidents.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a device according to an embodiment of the present invention for diagnosing abnormalities in the armature winding of a DC machine, FIG. 2 is a configuration diagram of the power supply device shown in FIG. 1, and FIG. An explanatory diagram of the current waveform and pulse waveform. Figure 4 is a comparison diagram of the electromagnetic force and vibration acceleration generated in the winding when there is no abnormality in the winding. Figure 5 is a comparison diagram of the electromagnetic force and the vibration acceleration generated in the winding when there is an abnormality. FIG. 4 is a comparison diagram of the vibration acceleration generated in the winding. In the figure, 2 is an armature winding, 10 is a power supply device, 11 is an accelerometer, and 110 is an oscilloscope, and numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. Vibrating means for forcibly vibrating the windings by passing a current of a predetermined frequency through the windings of the electrical equipment, directly detecting the vibration acceleration of the windings, and A detection means for detecting a load applied to the structure of the electrical equipment or a mechanical force based on the forced vibration of the winding, and a display means for displaying the detection result of the detection means as a vibration waveform, The means includes a phase angle control means for freely adjusting a phase angle at the time when current starts to be applied to the winding, and the phase angle control means generates an ignition pulse for each cycle of the output of the excitation means. ignition pulse generation means for counting the number of ignition pulses and controlling the phase angle at the point in time when the current begins to flow through the winding; 1. An abnormality diagnosing device for a winding of an electrical device, comprising a counting means for sending an operation stop signal to stop the flow of current to the winding. 2. The electrical device according to claim 1, wherein the detection means is a piezoelectric detection means that exchanges and outputs mechanical force based on forced vibration of a winding into an electrical signal depending on the magnitude of the mechanical force. Winding abnormality diagnosis device. 3. The apparatus for diagnosing an abnormality in a winding of an electrical device according to claim 1 or 2, wherein the vibration excitation means includes an adjustment means for adjusting the amplitude value of the output thereof. 4. An abnormality diagnosing device for a winding of an electrical device according to any one of claims 1 to 3, wherein the vibration excitation means applies an alternating current to the winding. 5. An abnormality diagnosis device for a winding of an electrical device according to any one of claims 1 to 4, wherein the electrical device is a rotating electric machine.