JPS5945092B2 - Abnormality diagnosis device for windings of electrical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is designed to detect abnormalities in the windings of electrical equipment, such as the windings incorporated in the stator, rotor, or armature of a rotating electrical machine (hereinafter referred to as a rotating machine), and the supporting state of the windings. The present invention relates to an abnormality diagnosis device for windings of electrical equipment that non-destructively detects defects.

For convenience of explanation, the case of a rotating machine will be described below.

In recent years, as rotary machines have become smaller and lighter, there has been a demand for higher reliability, and there has been a strong tendency for rotary machines to be used for longer periods than before.

Therefore, from the viewpoint of confirming the reliability of the windings of rotating machines and preventive maintenance against accidents, it has become important to non-destructively diagnose abnormalities in the windings and poor support conditions of the windings. J Conventionally,
There are technologies for detecting abnormalities in the windings of rotating machines.

(ii) When the winding loosens and a gap is created, mica powder (hereinafter referred to as powder) contained in the insulating mica sheet and mica tape flows through the gap and comes out to the outer gate.

There is a visual test to visually check whether this powder is present or not. In addition, there is a hammering test in which abnormalities are detected by striking the windings with a rotary hammer and a sound is detected, and (c) a method in which abnormalities are detected by changes in the ground current of a rotating machine (Japanese Patent Laid-Open No. 52
No. 1125701) etc.

However, these have the following drawbacks. (b) Visual inspection will not detect any abnormality if the bulge occurs in an area that cannot be seen from the outside.

(!In the case of hammering tests, the determination of normal and abnormal sounds is subjective, and it lacks reliability in that it is difficult to judge the progress of winding abnormalities. (f) Changes in ground current This is difficult to detect because the capacitance changes and the ground current changes depending on what is inserted between the coil and the core. This invention was developed in view of the above drawbacks, and the object of the present invention is to provide a device that can easily and accurately detect abnormalities in the windings of electrical equipment and defects in the winding support.

The means adopted in the present invention to achieve this purpose are (
b) Provide a power source that applies power at a predetermined frequency to the windings, and (
b) It is a waveform display of the displacement of the winding due to energization.

The above means (a) has the function of causing current to flow through the winding to cause the winding to vibrate.

The means (b) has the function of displaying the time course of the displacement due to this vibration in a waveform and making it possible to observe the waveform.
The above-mentioned vibration differs between a normal winding and a winding in which an abnormality such as loosening has occurred, and also differs depending on the degree of progress of the abnormality. Therefore, by observing the vibrations generated in the winding by means 6 (a) using means (b), it is possible to detect abnormalities in the winding. Judgment of the sound is subjective, and the progress of the winding abnormality is difficult to judge.Therefore, reliability is lacking.

(c) In the case of detection based on changes in ground current, detection is difficult because the capacitance changes depending on the object inserted between the coil and the core, and the ground current changes. The present invention has been made in view of the drawbacks of conventional winding inspections, and an object of the present invention is to provide a device that can easily and accurately detect abnormalities in windings and poor winding support of electrical equipment. With the goal.

The means adopted in the present invention to achieve this purpose are (
b) Provide a power source that applies power at a predetermined frequency to the windings, and (
! It is a waveform display of the displacement of the winding due to energization.

These methods made it possible to inspect windings for abnormalities through observation of displacement waveforms. The configuration of the present invention will be explained below with reference to the drawings of the first embodiment.

This invention! This winding abnormality diagnosis device is equipped with a core part, a winding vibration sensing part, and a waveform display part.
The figure is a circuit diagram showing one embodiment of the power supply unit 1.

In the main picture? AC power input terminals 2a, 2 of a predetermined frequency
b is connected to an autotransformer 41 via switch 3.
It is assumed that the autotransformer 4 can adjust the secondary voltage by moving the secondary side contacts. The output of the autotransformer 4 is applied to a transformer 5, and is applied via a thyristor circuit 6 to an output terminal 12a. Here, 8 is an ignition control circuit of the thyristor circuit 6, which generates a phase control signal from a part of the output of the transformer 5 and applies it to the trigger terminal 7 of the thyristor circuit 6 and the counter 9. In this device, a current exceeding the rated current is passed through the armature winding to facilitate vibration of the armature winding. Therefore, it is necessary to apply electricity only for a short period of time, for example, about several tens of cycles of the input frequency, to avoid heat generation in the winding. The counter 9 defines this time based on the control signal given from the ignition control circuit 8, and when a predetermined number of pulses are applied, it activates the ignition control circuit 8 and stops the conduction of the thyristor circuit 6. let Also, in the main picture? 10 is a current transformer; 11 is an ammeter for measuring the current flowing through the armature winding 13; and 12a and 12b are output terminals of the power supply section 1. Next, an embodiment of the winding vibration detection section will be described with reference to FIG. 2.

FIG. 2 is a partially cutaway perspective view showing the vicinity of the end of the armature winding.

In FIG. 1, a metal foil 14 is attached to one end of the armature winding 13.
is attached, and a displacement meter 15 is provided on the top of the metal foil 14 by a support (not shown) in a non-contact manner with the metal foil 14. When using the electromagnetic induction type for the displacement meter 15, the metal foil 1
4 uses a magnetic material. When using a capacitive type, the metal foil 14 is made of a conductive material to form one electrode, and another electrode is formed opposite to this, so that the displacement of the armature is controlled by changes in capacitance. Detect. In this figure, reference numeral 16 indicates an armature core, and reference numeral 17 indicates a wedge 18 for fixing the armature coil in the groove, a filler for preventing the wedge 17 from moving. A signal output terminal of this vibration detection section is connected to a waveform display section (not shown) consisting of an oscilloscope or the like.

Next, the operation of the abnormality diagnosis apparatus of the present invention will be explained with reference to FIGS. 3 to 6. FIG. 3a does not show the connection of an abnormality diagnosing device for detecting an abnormality in the rotor of a DC machine. In this figure, an armature main body 20 is fixed to a rotating shaft 21, and an armature winding 13 and a commutator 23 are integrally constructed. The rotating shaft 21 is supported by a bearing 25. The armature winding 13 is supported by supports 24 and fixed by a glass pan 22 made of a glass fiber reinforced composite material to avoid deformation due to centrifugal forces. Here, as shown in FIG. 3B, a sectional view taken along the line AOA-A in FIG. Further, the above-mentioned vibration detection section is installed at the end of the armature winding 13. FIG. 3a shows a state in which a metal foil 14 and a displacement gauge 15 are provided at the end of the armature winding 13. Next, a predetermined power is applied to the commutator 23 from the power source 1 to cause the armature winding 13 to vibrate.

The current supplied from the power source 1 can be phase-controlled by the thyristor circuit 6 to change the phase at which conduction starts, but as shown in Figures 4A and b, the current begins to conduct from point B (current phase is zero phase). It may also be controlled to start. Since the armature winding 13 vibrates when the power is turned on, this vibration state is detected by the vibration detection section and the waveform display section to diagnose abnormalities in the winding. Figures 5A and 5B show changes in two electromagnetic forces and displacement waveforms of the armature winding when there is no abnormality in the armature winding and the armature winding is well supported within the slot. It is.

In this case, the displacement is sinusoidal in response to changes in electromagnetic force. Figures 6A and 6B show changes in electromagnetic force and displacement waveforms of the armature winding when a board is formed inside the armature winding or when the support condition in the slot of the armature winding is improper. This is what is shown.

During such an abnormality, the armature winding undergoes nonlinear vibration or collision vibration within the slot, so the displacement of the armature winding is small above the fundamental wave corresponding to the change in electromagnetic force, as shown in Figure 6b. The vibrations are superimposed and the Blato phenomenon appears. Therefore, by measuring the displacement of the armature winding 13, it is possible to diagnose an abnormality in the armature winding or an improper support state from the shape of the displacement waveform. In the embodiment, the case where the power supply 1 is AC is described, but even if the current with a half-wave rectified waveform is configured to flow through the armature winding 13, the waveform has a predetermined frequency. If so, the abnormality can be diagnosed in the same manner as in the embodiment.

In addition, in this example, abnormalities and poor support conditions of the armature winding were detected based on the displacement of the armature winding, but an acceleration detector was attached to the armature winding and the acceleration was measured by integrating the number. Displacement may also be determined.

Furthermore, the present invention is effective in diagnosing abnormalities in the windings of other rotating machines such as various generators and induction machines, in addition to detecting abnormalities in the armature windings of DC machines as described in the above explanation examples. Needless to say, it is.

In the embodiment, the example 1 of a rotary tonnage machine has been described as an electrical device, but the present invention can of course be applied to diagnosis of other electrical devices such as transformer windings due to its principle. be.

As described above, according to the configuration of the present invention, it is possible to non-destructively detect an abnormality in the winding of an electrical device or a defect in the supporting state of the winding.

Additionally, abnormalities can be detected more accurately and objectively than conventional methods. Therefore, it is possible to diagnose abnormalities and defects in the winding condition of electrical equipment during its manufacture and after it has been in operation for a certain period of time, resulting in great effects in improving the reliability of electrical equipment and preventing accidents.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the power supply of the abnormality diagnosis device of the present invention, FIG. Figures 3A and 3B are connection diagrams when detecting an abnormality in the winding of a DC machine using the abnormality diagnosis device of the present invention, Figure 4 is a time chart without showing waveforms at each part of the tortoise source, and Figures 5 and 6 are time charts. This is a time chart showing the time change of the electromagnetic force and displacement of the straight armature winding.
The figure shows an abnormal situation. 1...Power supply, 6...Thyristor circuit,
8... Ignition control circuit, 13... Armature winding, 15... Displacement meter.

Claims (1)

[Scope of Claims] 1. A power supply that applies power at a predetermined frequency to a winding, a vibration detection means that detects vibrations of a winding of an electrical device when power is applied from the power supply, and 1. An abnormality diagnosis device for a winding of an electrical device, comprising: display means for displaying displacement of a winding of the electrical device based on a signal. 2. The abnormality diagnosis device for a winding of an electrical device according to claim 1, wherein the vibration detecting means is a displacement detector that detects displacement of the winding. 3. An abnormality diagnosis device for a winding of an electrical device according to claim 1 or 2, wherein the power source includes an amplitude value adjusting means for adjusting an amplitude value of the output voltage. 4. The winding of an electrical device according to claim 1, 2 or 3, wherein the power source is equipped with a phase angle control device that freely adjusts the phase angle at the time of generation of the output voltage. Abnormality diagnosis device. 5. The power supply phase angle control device generates an ignition pulse every cycle to control the phase angle at the time when the output voltage is generated, and further includes a counter that counts the number of ignition pulses, 5. An abnormality diagnosing device for a winding of an electrical device according to any one of claims 1 to 4, characterized in that the device is configured to stop supplying power after counting a predetermined number of pulses. 6. The apparatus for diagnosing an abnormality in a winding of an electrical device according to any one of claims 1 to 5, wherein the electrical device is a rotating electrical machine. 7. An abnormality diagnosis device for a winding of an electrical device according to any one of claims 1 to 6, wherein the power source is an alternating current power source.