JPS5812555A - Rotor coil defect diagnosing device for rotary electric machine - Google Patents

Abstract

PURPOSE:To accurately and rapidly perform the diagnosis of the defect of a coil to be detected for the presence or absence of the defect by obtaining a position signal with a rotor position detector installed and discriminating a pulsating wave form signal from a magnetic flux detector synchronously with the position signal. CONSTITUTION:A magnetic flux detector 13 is installed oppositely to a rotor 3, and a pulsating waveform signal of the output signal of the detector is inputted to a discriminator 18. Further, a position detector 39 for detecting the position of the rotor is installed, and the position signal of the output signal is inputted to the discriminator 18. Only the pulsating waveform signal corresponding to the predetermined rotor position is produced synchronously with the position signal to discriminate the presence or absence of the defect. In this manner, only the pulsating waveform component of the magnetic flux generated by the current flowing through the rotor coil to be discriminated for the presence or absence of the defect is extracted to discriminate the defect. Accordingly, the defect can be accurately and rapidly diagnosed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotor winding abnormality diagnosing device for a rotating electric machine such as a large-capacity turbine generator, and more particularly to an abnormality diagnosing device suitable for detecting an interlayer short circuit in a rotor winding. .

Generally, a large capacity turbine generator is as shown in Figure 1.
The rotor 8 is composed of a stator 1 and a rotor 8 disposed opposite to the stator 1 with a gap 2 interposed therebetween.

The stator l is composed of a stator winding, that is, an armature winding 5, wound around a laminated stator core 4, and the rotor 8 has a body part formed integrally with the shaft part 6. , that is, the rotor core 7 and the rotor winding, that is, the 5
It is constructed by winding a field winding 8 consisting of ~10 layers of conductors, and the rotating pre-winding 1i18 is held in the slot by a wedge 9, and its end is covered with a retaining ring 10. There is.

By the way, if the interlayer insulation of the rotor winding is destroyed due to the winding's thermal expansion or mechanical shock, and the winding is short-circuited, generally in a two-pole turbine generator, the N pole side of the rotor and the SaW origin Magnetic imbalance occurs, including magnetic force imbalance,
As a result, abnormal vibration occurs. When abnormal vibration occurs,
There is a risk that the generator will be adversely affected, such as damage to the generator's bearings or breakdown of the insulation in the windings, and may eventually become inoperable. Therefore, it is necessary to promptly detect an interlayer short circuit in the rotor winding and take necessary measures.

A known method for detecting this interlayer short circuit in the rotor winding will be described below.

In FIG. 1, FIG. 2(a) schematically shows the flow of magnetic flux in a plane where the rotor is sliced into rings, that is, a plane in which a radial cross section is developed. The magnetic flux is roughly divided into two types; one is a main magnetic flux 11 shown by a solid line in the figure, and the other is a leakage magnetic flux 12 that surrounds the rotor winding and shown by a broken line. For the purpose of capturing this leakage magnetic flux 12, for example, a magnetic flux detection element 18 such as a stationary search coil is installed in the air gap. Then, the leakage magnetic flux 12 generated when a current flows through the rotating pre-winding #8 is caught.

FIG. 2(b) shows the waveform of this leakage flux, and its magnitude is closely related to the product of the current flowing through the rotor winding conductors surrounding the leakage flux and the number of conductors, that is, the amperage. As the ampere frequency decreases, the leakage magnetic flux decreases, and conversely, as the ampere frequency increases, the leakage magnetic flux increases accordingly.

Therefore, when an interlayer short circuit occurs in the rotor winding, the number of amperes generated by that winding decreases, and the amount of leakage magnetic flux also decreases.

On the other hand, the search coil 111 for detecting leakage magnetic flux generates an induced voltage with a pulsating waveform corresponding to the leakage magnetic flux, as shown in FIG. 2(C). If the rotor winding is healthy, it will have a pulsating waveform as shown by the solid line 14, for example. However, if an interlayer short circuit occurs in a certain rotor winding, and the leakage magnetic flux at that part becomes small as shown by the broken line 15 in Fig. 2(C), The peak value of the pulsating waveform corresponding to the winding becomes smaller. In general, in a rotary electric machine such as a turbine generator, magnetic flux is equal in magnitude and opposite in sign on the N-pole side and the 8-pole side, and leakage magnetic flux and induced voltage of the search coil for detecting magnetic flux are also the same. It has symmetry.

From the above, in the induced voltage waveform of the search coil, the peak value of each group of the pulsating waveform corresponding to Ni11411 and the S pole side, for example, the peak value PL in FIG. 12(C).

Q, to see if there is a difference in size, and if there is a significant difference, it is determined that a glabella short circuit has occurred in the rotor winding with the smaller peak value.

Therefore, conventionally, a person took a photograph of the signal waveform from the magnetic flux detection element and compared the corresponding points on the north and south pole sides to check for interlayer short circuits. This takes time and effort, is inefficient, and makes it difficult to deal with emergencies.

Furthermore, in response to the demands of the times, there has recently been a desire to constantly monitor on-line the presence or absence of interlayer short circuits in the rotor windings of turbine generators, and automatic diagnostic devices such as those described below have been considered.

FIG. 8 is a schematic block diagram of the automatic diagnostic device.

In the figure, reference numeral 16 denotes a rotating electrical machine section consisting of a rotating electrical machine and a magnetic flux detecting element attached thereto, and a pulsating waveform signal detected by the magnetic flux detecting element is sent to a determination device 18 through a signal line 17. Judgment value [18 can be roughly divided into processing equipment [
19 and a monitoring device 21, the processing device 19 captures the peak values of each group of signal waveforms and performs abnormality diagnosis processing to determine whether there is an abnormality in the turbine generator. If it is determined that there is an abnormality in the turbine generator, a signal notifying the abnormality is transmitted through the signal line 20 to the monitoring device 21, where the signal is processed.

FIG. 8 has a specific configuration as shown in FIG. 4, for example. In FIG. 4, a magnetic flux detection element 18, for example a search coil, is installed near the surface of the rotor 80, and is used to detect magnetic flux, such as leakage flux, generated near the surface of the rotor 80 by current flowing through the rotor windings. The pulsating waveform signal generated in the magnetic flux detection element 18 by the electromagnetic induction effect of this leakage magnetic flux is transmitted to the processing device 19 in the determination device 18 through the signal line 17.Then, the signal is First, the amplifier 22 adjusts the size to an appropriate value, and transmits it to the peak value holder 24 through the signal line 28, and then to the comparator 25 through the signal line 26a. The wave height value is held for a sufficient period of time to input the signal, and the holding is automatically released before the next pulsating wave height value arrives, so that the comparator 25 starts inputting the wave height value. When the input start signal indicating that the signal is OK is output to the peak value holder 24 through the signal @ gab, the peak value signal is sent to the comparator 25 through the signal line 26.
Transmit through a.

The comparator 25 sequentially inputs the peak values held by the peak value holder 24 for one cycle and sends the data to the signal #28.
A is stored in the recorder 27 through a, and on the other hand, one after another,
Input the peak value data of the symmetrical part from the recorder 27 through the signal line 28b, compare the peak value data of the symmetrical parts,
It is checked whether the difference between the two with respect to the larger peak value, that is, the relative difference, exceeds a set level such as 10%. If the set level is exceeded, it is determined that there is an abnormality, and a signal is transmitted to the monitoring device 21 through the signals m 20a and 20b to inform the monitoring device 21 of the extent of the abnormality and the location where the abnormality has occurred.

The monitoring device 21 is an alarm device z9 consisting of an alarm lamp, a buzzer, etc. that is activated by a signal transmitted by the signal m20a.
and a display panel 80 that displays the location of the abnormality and the degree of the abnormality using a signal on the signal line 20b.

According to this automatic diagnostic device, it is possible to automatically determine the presence or absence of an interlayer short circuit in a rotor winding in a turbine generator or the like. However, automatic diagnostic devices in general, including this example, have the following drawbacks.

As shown in Fig. 5, some turbine generators have a groove 82 in the magnetic pole part 81 and a conductor inserted into the groove 82 in order to prevent the rotation speed from deviating from the rated rotation speed (for example, 8600 rpm). Some have damper windings 88 with all conductors shorted at the ends. When the groove 82 is installed in the magnetic pole part 81 in this way, the main magnetic flux in this part is as shown in FIG. 5(a).
As the flow curves around the corner 82a of the magnetic pole groove 82 as shown in a, a change in magnetic flux occurs, and a pulsating component corresponding to the magnetic pole #182 is generated in the magnetic flux detection element 18. The pulsating waveform of the signal obtained from 18 is k as shown in FIG. 5 Φ). It is very difficult for an automatic diagnostic device to reliably detect the pulsating waveform of the rotor winding groove portion 84 from this pulsating waveform, and it is difficult for an automatic diagnostic device to reliably find the pulsating waveform of the rotor winding groove portion 84 from this pulsating waveform. The presence or absence of an abnormality is determined and the magnetic flux flows like a stripe, and the magnetic flux at the groove outlet passes through the magnetic wedge, and the concentration of magnetic flux at the corner of the magnetic pole is relaxed, so the change in magnetic flux at the groove position becomes small (Figure 6). During)). As a result, the pulsating waveform of the signal induced in the magnetic flux detecting element becomes as shown in FIG. 6(e), and the pulsating waveform peak value 87 at the position of the rotor winding groove 85a where the magnetic wedge 86 is inserted becomes small. By the way, if this wave height value 87 is so small that it cannot be detected by the magnetic flux detection element, the automatic diagnostic device considers the wave height value 88 of the adjacent groove 85b in which no magnetic wedge is included as the wave height value of the first groove. There was a risk of mistakenly determining the catfish.

An object of the present invention is to accurately capture only the pulsating waveform component due to the magnetic flux generated by the current flowing through the rotor winding to determine the presence or absence of an abnormality, and to accurately, reliably, and quickly determine the presence or absence of an abnormality in the rotor winding. An object of the present invention is to provide a rotor winding abnormality diagnosing device for a rotating electric machine that can determine the following.

In order to achieve this object, the present invention provides a rotor position detection device, and sends a position signal synchronized to the rotation of the rotor obtained from the rotor position detection device to a determination device together with a pulsating waveform signal from a magnetic flux detection element. The present invention is characterized in that only the wave corresponding to a predetermined rotor position among the five groups of the input pulsating waveform signal, that is, the position of the rotor winding where the presence or absence of an abnormality is to be determined is determined as valid. .

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

FIG. 7 is a block diagram showing the overall configuration of a rotor winding abnormality diagnosing device according to an embodiment of the present invention.

In the figure, in addition to the magnetic flux detection element 18 shown in FIG. 4, the rotating electrical machine section 16 is provided with an element 89, such as a reflective photoelectric pickup, for accurately detecting the position of the rotor 800 rotations. A mark 40, such as a reflector, is attached to the rotor, and the rotational position detection element 89 is attached to the mark 40.
When 0 is detected, a pulsed position signal 44 as shown in FIG. 8 is generated. This position signal is sent through a signal line 41 to a determination device (18, which is sent to a processing device 19, and is converted into a pulse signal of a predetermined size and width by a waveform shaper 42), and is transmitted through a signal line 48 to a comparison and determination device 25 sent to.

By the way, when the temporal relationship between the pulsating waveform induced in the magnetic flux detection element 1B and the pulse position signal is as shown in FIG. , held in the peak value holder 24,
Input the peak values of the pulsating waveform in sequence.

As shown in FIG. 8, one rotation is divided into a first half cycle 46 and a second half cycle 47, and each time the comparator 25 inputs one wave height value data of the first half cycle, it passes the signal line 28a to the recorder 2.
Record in 7. After inputting all the wave height data of the first half cycle, every time the wave height data of the second half cycle is taken in, the wave height data stored in the recorder 27 at the symmetrical position to the currently taken wave height value is input through the signal line 28b. Incorporate,
By sequentially comparing the wave height data of these symmetrical positions,
Calculate the degree of abnormality, check whether the degree exceeds a certain set level, and determine whether or not there is an abnormality. If an abnormality is detected, a signal informing the monitoring device 21 of the extent of the abnormality and the location where the abnormality has occurred is transmitted through the signal line 20a and Bob. The configuration of the monitoring device 21 is the same as that shown in FIG.

According to this embodiment, it is possible to accurately and automatically determine whether there is an interlayer short circuit in a rotor winding in a turbine generator or the like. In other words, an element that detects the rotational position of a rotating electric machine such as a turbine generator is installed, and the rotational position signal obtained from this element is input into a determination device to accurately capture the rotational position and determine the position of the rotor winding groove. Accurately grasp and input the pulsating waveform induced into the magnetic flux detection element installed near the rotor surface. Therefore, the wave height value can be accurately determined without being affected by the pulsating component caused by the magnetic pole groove installed in the rotor or by the elimination of the pulsating component caused by the magnetic wedge installed in the rotor winding groove. Since it can be imported, a reliable diagnosis can be made.

FIG. 9 shows another embodiment of the present invention. In this embodiment, the position of the position detection mark 40 attached to the rotor is adjusted to detect the pulsating waveform induced in the magnetic flux detection element 18. K so that the pulse position signal 44 is output from the rotational position detection element 89 at the peak value position 48 of the first rotor winding groove.
It has become. Therefore, in this case, the comparator 2
5 takes in the pulse position signal 44 until it takes in the peak value data.
You can input the peak value data of the th rotor winding groove.

FIG. 10 shows an embodiment in which a plurality of pulse position signals 44 are obtained from the position detection element B9, and in particular, each pulse position signal 44 corresponds to each peak value position 49 of the rotor winding groove.
The plurality of position detection marks 40 are adjusted so that 4 appears,
is set up. Therefore, in this case, the comparator 25 only needs to take in the peak value data after inputting the pulse position signal, and since it can accurately take in each piece of peak value data, the reliability of the device is greatly improved.

As described above, according to the present invention, a rotor position detection device is provided, and a determination device uses a position signal synchronized with the rotation of the rotor obtained from the rotor position detection device together with a pulsating waveform signal from a magnetic flux detection element. , and out of each branch of the pulsating waveform signal, only the wave corresponding to the predetermined rotor position, that is, the position of the rotor winding where the presence or absence of an abnormality should be determined, is judged as valid. Accurately captures only the pulsating waveform component due to the magnetic flux generated by the current flowing through the rotor winding to determine the presence or absence of abnormalities in the rotor winding accurately, reliably, and quickly. can do.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the equipment showing the schematic configuration of the turbine generator;
Figures 2 (a) to (C) are schematic diagrams showing the flow of magnetic flux on the rotor surface, a pulsating waveform diagram of leakage magnetic flux on the rotor surface, a pulsating waveform diagram of the induced voltage generated in the search coil, and Figure 8
4 and 4 are a schematic block diagram and a detailed block diagram of a conventional rotor winding abnormality diagnosis device, and FIG. 5 (a), Φ)
6(a) to (C) are pulsation waveform diagrams showing the flow of magnetic flux on the rotor surface and the induced voltage generated in the search coil on each side, and FIG. 7 is a rotor according to an embodiment of the present invention. The block diagram of the winding abnormality diagnosing device, FIGS. 8 to 10, are time charts showing each side of the temporal relationship between the pulsating waveform of the induced voltage generated in the search coil and the position-signal. l...Stator, 2...Gap, 8...Rotor, 18...
...Magnetic flux detection element, 16...Rotating electric machine section, 18...Song...judgment device, 19...
Processing device, 81...Monitoring device, 22...
......Amplifier, 24...... Peak value holder, 25......Ratio, 20 f3λ 74EEt, Z? '5E2T O6 (a) '77 Figure 2 a Figure 2 Meals 9 Review

Claims (1)

[Claims] 1. A stator formed by winding a stator winding around a stator core;
A rotor is arranged to face the stator with an air gap in between and has a rotor winding wound around a rotor core, and a rotor is arranged near the surface of the rotor and has a current flowing through the rotor winding. A magnetic flux detection element that detects magnetic flux generated near the rotor surface, and a determination device that inputs a pulsating waveform signal obtained from the magnetic flux detection element to determine whether there is an abnormality in the rotor winding, A position detection device for detecting the rotor position is provided, and a position signal synchronized with the rotation of the rotor obtained from the position detection device is inputted to the determination device, and a predetermined rotor position is determined from among the six waves of the pulsating waveform signal. A rotor winding abnormality diagnostic device for a rotating electrical machine, characterized in that only waves corresponding to the above are determined to be valid. 2. In claim 1, the determination device comprises:
In the pulsating waveform signal, the peak values of six waves of the pulsating waveform component corresponding to the first magnetic pole of the rotor, and the six waves of the pulsating waveform component corresponding to the second magnetic pole different from the first magnetic pole of the rotor. A rotor winding abnormality diagnosing device for a rotating electric machine, characterized in that the apparatus compares peak values of waves to determine the presence or absence of an abnormality in the rotor winding. 8. In claim 2, the determination device comprises:
6 of the pulsating waveform components to be compared in the pulsating waveform signal
A wave height holding means for sequentially inputting wave height values and holding them for a predetermined time; and a wave height holding means for sequentially inputting wave height values of six waves of the pulsating waveform component in a predetermined temporal relationship with the position signal from the wave height holding means; a storage means for storing, and the wave height values of the six waves of the pulsating waveform component newly held in the wave height value holding means are sequentially input in a predetermined temporal relationship with the position signal, and the pulsation is stored in the storage means; A rotor winding abnormality diagnostic device for a rotating electric machine, comprising a comparison judgment means for comparing the wave height values of six waves of a waveform component and outputting an abnormality signal when the difference is greater than a predetermined value. 4. In claim 2, the position detection device generates the position signal at a rotor position that is shifted by a predetermined phase with respect to a peak value position of a predetermined wave of the pulsating waveform signal. A rotor winding abnormality diagnostic device for a rotating electric machine, which is characterized by: 5. In claim 2, the position detection device generates the position signal at a rotor position corresponding to a peak value position of a predetermined wave of the pulsating waveform signal. Rotor winding abnormality diagnosis device for rotating electric machines. 6. In claim 2, the position detection device generates the position signal at each rotor position corresponding to the peak value position of all waves to be made valid in the pulsating waveform signal. A rotor winding abnormality diagnostic device for a rotating electric machine, characterized in that: