JP2839528B2 - Field winding interlayer short-circuit position detection device - Google Patents

Description

Description: Object of the Invention (Industrial application field) The present invention relates to an apparatus for detecting an interlayer short-circuit position of a field winding of a rotating electric machine having a cylindrical rotor.

(Prior Art) As means for detecting the presence or absence of an interlayer short-circuit and the position of an interlayer short-circuit in a field winding of a rotating electric machine, for example, the literature IEEE Transacti
ons Paper (july31 1970) “INTERTURN SHORT CIRCUIT
There is a detection method described in "D-ETECTOR FOR TURBINE-GENERATOR ROTORWINDING". In this method, a probe with a built-in search coil for measuring air gap magnetic flux is attached near the rotor, and the field winding is attached to the rotor when the rotor rotates. A current is applied and a voltage induced in the search coil is input to a synchroscope and its waveform is recorded in a photograph.If an interlayer short-circuit occurs in the field winding, the search coil corresponding to the field winding short-circuited in the interlayer Paying attention to the fact that the induced voltage of the magnetic field becomes low, the position of the magnetic pole is detected from the voltage waveform recorded in the photograph and the signal obtained by the rotor position detecting element.

(Problems to be Solved by the Invention) However, conventionally, as described above, a voltage waveform recorded in a photograph is observed to determine a short-circuit between layers of a winding. There was a disadvantage that it lacked. The present invention solves the above-mentioned problems of the prior art, automatically analyzes the output waveform of the magnetic flux detecting means, and can detect the short-circuited position between the field windings with high reliability, which can quickly determine the short-circuiting between the windings. It is intended to provide a device.

[Configuration of the invention]

(Means for Solving the Problems) In order to achieve the above object, a field winding interlayer short-circuit detecting device of the present invention detects a magnetic flux generated by a current flowing through a field winding accommodated in a slot of a rotor. Magnetic flux detecting means, and a rotor position detecting means for detecting the position of the rotor,
An inter-layer short-circuit position detecting means for inputting an output voltage obtained from the magnetic flux detecting means and detecting an inter-layer short-circuit position of the field winding. The means is provided so as to obtain a trigger pulse at the center of the magnetic pole of the rotor. The output voltage of the magnetic flux detecting means during one rotation of the rotor is changed from the rising of the trigger pulse of the output voltage obtained by the rotor detecting means. Output voltage storage means for sequentially storing all peak values of the output voltage as digital data with one cycle until the fall,
A peak value calculating means connected to the output voltage storing means for calculating an output voltage peak value corresponding to each slot of the output voltage; and an output voltage corresponding to each slot obtained by the peak value calculating means. Deviation calculation processing means for obtaining a standard deviation for the distance between peaks and eliminating peak values not corresponding to the field winding, and the output voltage corresponding to each magnetic pole slot of the rotor determined by the rotor position detection means Comparing the distance between the peaks between the slots symmetrical with respect to the magnetic pole center line, determining whether the deviation is within a determination reference value, and providing a comparison determination means for outputting the interlayer short-circuit position of the field winding. Characteristic device for detecting short-circuit position between field winding layers.

(Operation) Since the present invention is configured as described above, while continuously monitoring the change in the air gap magnetic flux, the trigger pulse signal which is the output of the rotor position detecting means for detecting at a predetermined rotor position is used. Calculation of the deviation of the peak value of the output voltage of the magnetic flux detection means, which is the change of the air gap magnetic flux to be compared,
By outputting the slot position having a large deviation by the comparison / determination means, the short-circuit position of the field winding can be easily detected.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of the present embodiment. As shown in the figure, the output voltage Vp corresponding to the change in the air gap magnetic flux by the search coil of the probe of the magnetic flux detector (1) attached near the rotor is passed through the high-speed A / D converter (3) and stored in the memory (5). ) Is stored. The output voltage Vt of the rotor position detecting device (2) is stored in the memory (6) through the high-speed A / D converter (4).

As shown in FIG. 2, the probe output waveform (10) of the signal stored in the memory (5) is the rising or rising of the rotor position detection device output waveform (11) of the signal stored in the memory (6). The signals are divided into signal groups M1, M2, M3,. This signal group M1, M
For each of 2, M3,..., Each peak value of the output shown in FIG. 2 is obtained by the peak value calculation processing means (9), and these peak values are numbered P1 to P58. Now, if the output voltage Vt of the rotor position detecting device (2) is installed so as to rise or fall at the center of the second magnetic pole shown in FIG. 2, the preceding numbers P1 to P29 of the peak values P1 to P58 and Rear number P30
PP58, and are numbered A1 to A27 and B1 to B27 according to the groups to be compared shown in FIG.
Then, A1 and A2, A3 and A
4, distance between A13 and A14, A14 and A15, A16 and A17, ... A26 and A
27 distance, B1 and B2, B3 and B4, ... distance between B13 and B14, B14 and B
15, B16 and B17, ... The distance between B26 and B27 is calculated.

The calculation result obtained by the displacement calculation processing means (19) is compared with a predetermined judgment criterion (21), and the comparison and judgment of interlayer short-circuit is performed by the comparison judgment means (20). The presence or absence of an interlayer short-circuit and the position of the short-circuit are output as the processing results of the system (8).

The determination method performed in the above-described comparison determination means (20) is performed by the following method including the improvement of accuracy.

In calculating the peak value of the search coil output voltage of the probe, using the total number of peak values and the symmetry of the magnetic poles of the rotor, numbering A and B corresponding to each slot as shown in FIG. 3, Let the peak value be calculated. A1 to A1, which are respectively numbered with respect to the signal groups M1, M2, M3,.
The standard deviation is calculated for the distances corresponding to 27 and B1 to B27, and the effects of noise and the peak value P that does not correspond to the field winding are excluded, and the comparison / judgment is performed using the optimum value.

Thereafter, the opposite numbers of A and B are compared with each other (the addition numbers of A and B correspond to 27 and 28 in the slot comparison with the magnetic pole center line symmetrical here). Then, the slot numbers of the magnetic poles are compared with each other.

As a result, if there is a low portion, it is determined that there is an interlayer short circuit at the position of the corresponding magnetic pole and slot number. For example, when all the field windings are healthy, the distance between A1 and A2 is equal to the distance between B1 and B2, and the other numbers A3 to A27 and B3 to B27 also have the same distance.

Next, a specific embodiment of the present invention will be described with reference to FIG.

Voltages corresponding to the respective processes of A1 to A27 and B1 to B27 are generated corresponding to the slots (13) of the rotor (12) in FIG. Therefore, for example, if an interlayer short circuit occurs in the coil in the slot corresponding to the voltage corresponding to the distance between A1 and A2, A1
And the distance between A2 and the distance between B26 and B27 are lower than in a healthy case. Therefore, an interlayer short circuit can be detected by comparing the distances of A and B having the same number. To realize this peak value calculation processing and comparison operation, calculate the peak value of the search coil output voltage Vp of the probe,
Utilizing the total number of peak values for one rotation (one cycle) of the rotor (12) and the symmetry of the magnetic pole of the turbine generator rotor, as shown in FIG. The place appearing at / 4 + 1 corresponds to A14 and B14. As described above, the calculation for finding the peak value corresponding to each slot of the peak value of the search coil voltage of the probe is performed, the distance between the peak values to be compared is allocated, and the calculation processing method for comparing is provided. Also, as a noise countermeasure, the signal group M
For 1, M2,..., Standard deviations are obtained for distances corresponding to A1 to A27 and B1 to B27, respectively, and a final comparison is made with an optimum value for determination.

The output voltage Vt of one rotor position detector (2) attached to the center of the magnetic pole is stored in the memory through the A / D converter (4), and one cycle from one rise of Vt to the next fall is taken. As the probe search coil output voltage Vp
The peak value is obtained for each digital data amount of the slot portion corresponding to the rotation speed at the time of measurement. And
The total peak amount is obtained, and A1 to A27, B1 to A4, B14 are set to 1/4 + 1th and 3/4 + 1th peak values of the total number of peak values.
Number B27. Then, the distance between A1 and A2 ~ B26 and B2
The distance of A1 and A2 and the distance of B26 and B27 are assigned as the first slot of the magnetic pole 1, and the distance of B1 and B2 and A2
The distance between 6 and A27 is assigned as the first slot of the magnetic pole 2. According to the comparison between A and B, if there is a lower portion, it is determined that there is an interlayer short-circuit at a position corresponding to the magnetic pole and the slot number. Also, the comparison of the slot numbers of the magnetic poles is performed.

As in the present embodiment, the output voltage waveform of the search coil is stored as digital data, and the distance between the output voltage peaks at the position corresponding to each slot of each magnetic pole is calculated by using this data. By doing so, the rate of change in the air gap magnetic flux due to the current flowing through the field windings accommodated in each slot is accurately obtained, and the accuracy of the determination of an interlayer short circuit is increased. In addition, a memory device with an A / D converter has a large buffer memory at present. The data converted into digital data is output as a waveform. Thereby, the peak value which does not correspond to the field winding of the slot can be canceled by operating the computer keyboard.

〔The invention's effect〕

As described above, according to the present invention, the field winding capable of checking the waveform of the output voltage of the magnetic flux detecting means for measuring the air gap magnetic flux, detecting the interlayer short-circuit of the winding quickly and reliably, and detecting the position of the interlayer short-circuit. It is possible to provide a device for detecting a short-circuit position between line layers.

[Brief description of the drawings]

FIG. 1 is a block diagram of an apparatus for detecting a short-circuited position between field windings according to an embodiment of the present invention, FIG. 2 is an example of a search coil output voltage waveform of a probe for measuring air gap magnetic flux, and FIG. FIG. 4 is an explanatory diagram showing a peak value required for the comparison means in FIG.
The figure is a sectional view showing the positional relationship between the probe and the rotor. (1)… magnetic flux detector, (2)… rotor position detector (3), (4)… A / D converter, (5), (6)… memory (7)… sampling Unit, (8) Calculation processing system (9) Peak value calculation processing means (10) Probe output waveform (11) Rotor position detector output waveform (12) Rotor ( 13) Slot, (14) Field winding (15) Probe, (16) Search coil (17) Probe lead wire, (18) Magnetic pole (19) Polarized Position calculation processing means, (20)... Comparison determination means (21).

Claims (1)

(57) [Claims] A magnetic flux detecting means for detecting a magnetic flux generated by a current flowing through a field winding accommodated in a slot of the rotor; a rotor position detecting means for detecting a position of the rotor; An inter-layer short-circuit position detecting means for inputting a trigger pulse obtained from a detecting means and an output voltage obtained from the magnetic flux detecting means to detect an inter-layer short-circuit position of the field winding; In the apparatus, the rotor position detecting means is provided so as to obtain a trigger pulse at the center of the magnetic pole of the rotor, and the output voltage of the magnetic flux detecting means during one rotation of the rotor can be obtained by the rotor detecting means. Output voltage storage means for sequentially storing all peak values of the output voltage as digital data with one cycle from the rise to the fall of the trigger pulse of the output voltage; A peak value calculation processing means connected to the output voltage calculation section for calculating an output voltage peak value corresponding to each slot of the output voltage; and a distance between each output voltage peak corresponding to each slot obtained by the peak value calculation processing means. Deviation calculation processing means for determining the standard deviation and eliminating peak values not corresponding to the field winding, and the distance between the output voltage peaks corresponding to each magnetic pole slot of the rotor determined by the rotor position detection means. Comparing the slots having the symmetrical magnetic pole center line with each other, determining whether the deviation is within a determination reference value, and outputting the interlayer short-circuit position of the field winding. Winding layer short-circuit position detection device.