Methods, systems, and storage media for locating rotor-to-turn short-circuit faults in generators

Abstract

This invention relates to a method, system, and storage medium for locating rotor inter-turn short-circuit faults in a generator. The method includes: real-time acquisition of multiple induced electromotive forces (EMFs) detected by a flux detection coil during one revolution of the generator rotor; determining the induced EMF corresponding to each rotor slot under each magnetic pole based on the data values ​​and acquisition sequence number of the multiple induced EMFs; comparing the absolute values ​​of the induced EMFs corresponding to the corresponding rotor slots under different magnetic poles, and using the induced EMF with the smallest absolute value as the first data, and the induced EMF with a non-minimum absolute value as the second data; and determining whether an inter-turn short-circuit fault has occurred in the corresponding rotor slot under the corresponding magnetic pole corresponding to the first data based on the difference in absolute values ​​between the first and second data. The technical solution of this invention does not rely on rotor phase detection signals, is applicable to generators with asymmetrical magnetic pole structures, and is unaffected by load conditions and speed changes.

Description

Technical Field

[0001] This invention relates to the field of power systems, and more particularly to a method, system, and storage medium for locating rotor-to-turn short-circuit faults in a generator. Background Technology

[0002] Inter-turn short circuits in rotor windings are a common electrical fault in synchronous generators. The basic principle of existing online fault monitoring devices is as follows: Figure 1 As shown, multiple rotor slots are symmetrically distributed between the magnetic poles, and the rotor windings (excitation windings) are embedded in the rotor slots. The main rotor magnetic field is generated by all rotor coils. Although a short circuit between rotor winding turns affects the strength of the main magnetic flux, it is difficult to measure because its proportion is very small. The leakage flux, however, links to the rotor windings in each slot, and its magnitude is proportional to the number of turns in the rotor coil within that slot. It directly reflects the change in the number of turns in each slot's rotor coil. Therefore, existing online fault monitoring devices typically fix the flux detection coil on the stator and place it as close as possible to the rotor core. This flux detection coil can detect the radial and tangential components of the leakage flux during rotor rotation and differentiate them. By analyzing the differential waveform, it can be determined whether a short circuit fault has occurred in the rotor windings.

[0003] The following is combined Figure 2 Explanation of the principle of the magnetic flux detection coil method when the generator is running under no-load: X1 is Figure 1 The rotor windings (after unfolding) are shown in Figure X2, with the leakage flux corresponding to the rotor windings in each rotor slot. Furthermore, if there is no inter-turn short circuit in the rotor windings, the peak envelopes X41 and X42 of the induced voltage X3 corresponding to each rotor slot are continuous and smooth, with the number and sequence of peaks corresponding one-to-one with the rotor slot. When an inter-turn short circuit exists in a certain slot of the rotor winding, the leakage flux linked to that slot decreases, and the induced potential on the flux detection coil decreases accordingly. The peak at the corresponding position in the induced potential waveform deviates from the envelope and becomes concave and shorter, indicating an inter-turn short circuit fault in the rotor winding of that slot.

[0004] However, existing online fault monitoring devices lack online fault location capabilities and can only rely on manual judgment based on waveforms. Even those devices with rotor winding inter-turn short-circuit fault location functions require rotor phase detection signals (i.e., rotor position information), and can only perform online inter-turn short-circuit fault location for generators with symmetrical magnetic poles. For generators with asymmetrical magnetic poles, such as... Figure 3 As shown, it is not possible to locate short-circuit faults between rotor turns. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method, system and storage medium for locating short-circuit faults between rotor turns of a generator, which is in view of the shortcomings of the existing technology that require the combination of rotor phase detection signals for fault location.

[0006] The technical solution adopted by this invention to solve its technical problem is: constructing a method for locating rotor inter-turn short-circuit faults in a generator, comprising:

[0007] Data acquisition steps: During the time it takes for the generator rotor to rotate one revolution, multiple induced electromotive forces detected by the magnetic flux detection coil are acquired in real time, wherein the magnetic flux detection coil is installed on the stator of the generator.

[0008] Determination steps: Based on the data values ​​and acquisition sequence numbers of the multiple induced electromotive forces, determine the induced electromotive force corresponding to each rotor slot under each magnetic pole;

[0009] Judgment steps: Compare the absolute values ​​of the induced electromotive forces corresponding to the rotor slots under different magnetic poles, and take the induced electromotive force with the smallest absolute value as the first data, and take the induced electromotive force with a non-small absolute value as the second data. Then, determine whether the rotor slot under the corresponding magnetic pole corresponding to the first data has an inter-turn short circuit fault based on the difference between the absolute values ​​of the first data and the second data.

[0010] Preferably, the determining step includes:

[0011] Step S21: Determine D / 2 positive peak voltages and D / 2 negative peak voltages based on the data values ​​of the plurality of induced electromotive forces, where D is the number of slots in the generator rotor;

[0012] Step S22: Based on the data values ​​and acquisition sequence numbers of the D / 2 positive peak voltages, determine the induced electromotive force corresponding to each rotor slot under each N magnetic pole; and based on the data values ​​and acquisition sequence numbers of the D / 2 negative peak voltages, determine the induced electromotive force corresponding to each rotor slot under each S magnetic pole.

[0013] Preferably, step S21 includes:

[0014] The plurality of induced potentials are divided into p positive voltage data groups and p negative voltage data groups according to their data values, where p is the number of magnetic pole pairs;

[0015] For each positive voltage data set, the local maximum data is filtered out, and the largest D / (2p) data are determined from the local maximum data, and the largest D / (2p) data are taken as the positive peak voltage.

[0016] For each negative voltage data set, the local minimum data is filtered out, and the smallest D / (2p) data are determined from the local minimum data, and the smallest D / (2p) data are taken as the negative peak voltage.

[0017] Preferably, the step of filtering out local maximum data includes:

[0018] The positive voltage data group is traversed by a sliding window. For the current sliding window, if the middle data in the current sliding window is greater than other data in the current sliding window, the middle data in the current sliding window is determined as the local maximum data. The length of the sliding window is an odd number greater than 1.

[0019] The process of filtering out local minimum data includes:

[0020] The negative voltage data set is traversed through a sliding window. If the middle data in the current sliding window is smaller than any other data in the current sliding window, then the middle data in the current sliding window is determined as the local minimum data.

[0021] Preferably, in step S22, the induced electromotive force corresponding to each rotor slot under each N pole is determined based on the data values ​​and acquisition sequence numbers of the D / 2 positive peak voltages, including:

[0022] For each group of D / (2p) positive peak voltages, sort them in ascending order, and then divide the sorted D / (2p) positive peak voltages into two groups in turn.

[0023] Using the center line of the corresponding N magnetic pole and its preceding S magnetic pole as the axis of symmetry, in order from the middle to both sides, the two positive peak voltages of each group are sequentially matched with the D / (2p) rotor slots under the corresponding N magnetic pole, and the rotor slots corresponding to the two positive peak voltages of each group are symmetrically distributed at both ends of the axis of symmetry. In addition, the rotor slots corresponding to the positive peak voltages with smaller acquisition numbers in the same group are located behind the rotor slots corresponding to the positive peak voltages with larger acquisition numbers along the rotor rotation direction of the motor.

[0024] Preferably, in step S22, the induced electromotive force corresponding to each rotor slot under each S pole is determined based on the data values ​​and acquisition sequence numbers of the D / 2 negative peak voltages, including:

[0025] For each group of D / (2p) negative peak voltages, sort them in descending order, and then divide the sorted D / (2p) negative peak voltages into two groups in sequence.

[0026] Using the center line of the corresponding S magnetic pole and its preceding N magnetic pole as the axis of symmetry, in order from the middle to both sides, the two negative peak voltages of each group are sequentially matched with the D / (2p) rotor slots under the corresponding S magnetic pole, and the rotor slots corresponding to the two negative peak voltages of each group are symmetrically distributed at both ends of the axis of symmetry. In addition, the rotor slots corresponding to the negative peak voltages with smaller acquisition numbers in the same group are located behind the rotor slots corresponding to the negative peak voltages with larger acquisition numbers along the rotor rotation direction of the motor.

[0027] Preferably, in the judgment step, determining whether an inter-turn short circuit fault has occurred in the corresponding rotor slot under the corresponding magnetic pole corresponding to the first data based on the absolute value difference between the first data and the second data includes:

[0028] Calculate the absolute difference between the first data and the second data;

[0029] Determine whether the absolute value difference is greater than a set value;

[0030] If the value is greater than the set value, it is determined that an inter-turn short circuit fault has occurred in the corresponding rotor slot under the magnetic pole corresponding to the first data.

[0031] The present invention also constructs a storage medium storing a computer program, which, when executed, implements the steps of the rotor inter-turn short-circuit fault location method for the generator described in any of the above claims.

[0032] The present invention also constructs a rotor inter-turn short-circuit fault location system for a generator, including a processor, which implements the steps of the above-described rotor inter-turn short-circuit fault location method for a generator when executing a stored computer program.

[0033] The present invention also constructs a rotor inter-turn short-circuit fault location system for a generator, comprising:

[0034] The acquisition module is used to acquire multiple induced electromotive forces detected by the magnetic flux detection coil in real time during the period of one rotation of the generator rotor, wherein the magnetic flux detection coil is installed on the stator of the generator.

[0035] The determination module is used to determine the induced electromotive force corresponding to each rotor slot under each magnetic pole based on the data values ​​and acquisition sequence number of the multiple induced electromotive forces.

[0036] The judgment module is used to compare the absolute values ​​of the induced electromotive forces corresponding to the corresponding rotor slots under different magnetic poles, and take the induced electromotive force with the smallest absolute value as the first data, and the induced electromotive force with a non-small absolute value as the second data. Based on the difference between the absolute values ​​of the first data and the second data, it is determined whether the corresponding rotor slot under the corresponding magnetic pole corresponding to the first data has an inter-turn short circuit fault.

[0037] The technical solution provided by this invention analyzes the data values ​​and acquisition sequence numbers of multiple induced electromotive forces collected by the flux detection coil during one revolution of the generator rotor. This allows for the determination of the induced electromotive force corresponding to each rotor slot under each magnetic pole. Then, by comparing the absolute values ​​and calculating the differences between the induced electromotive forces corresponding to the corresponding rotor slots under different magnetic poles, the inter-turn short-circuit fault can be located. Furthermore, this method does not rely on rotor phase detection signals, is applicable to generators with asymmetrical magnetic pole structures, and is unaffected by load conditions and speed variations, enabling reliable location of inter-turn short-circuit faults under all operating conditions. Attached Figure Description

[0038] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0039] Figure 1 This is a schematic diagram of a rotor winding with a symmetrical magnetic pole structure.

[0040] Figure 2 This is a schematic diagram of the principle of an existing online fault monitoring device;

[0041] Figure 3 This is a schematic diagram of a rotor winding with an asymmetric magnetic pole structure.

[0042] Figure 4 This is a flowchart of Embodiment 1 of the rotor inter-turn short circuit fault location method for the generator of the present invention;

[0043] Figure 5A This is a waveform diagram of the induced electromotive force detected by the flux detection coil during normal operation of a generator with an asymmetric magnetic pole structure;

[0044] Figure 5B This is a waveform diagram of the induced electromotive force detected by the flux detection coil when a generator with an asymmetric magnetic pole structure experiences a rotor inter-turn short circuit fault.

[0045] Figure 6 This is a logic structure diagram of Embodiment 1 of the rotor inter-turn short circuit fault location system for the generator of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Figure 4 This is a flowchart of a first embodiment of the rotor inter-turn short-circuit fault location method for the generator of the present invention. The rotor inter-turn short-circuit fault location method of this embodiment includes the following steps:

[0048] Data Acquisition Step S10: During the time period when the generator rotor rotates once, multiple induced electromotive forces detected by the magnetic flux detection coil are acquired in real time, wherein the magnetic flux detection coil is installed on the stator of the generator.

[0049] In this step, the flux detection coil is mounted on the stator of the generator, as close as possible to the rotor surface. There are no special requirements for its pitch and number of turns, and the sampling frequency f is generally not less than 50 kJ / s. Furthermore, when a certain asymmetrical generator is operating normally (without a short-circuit fault between rotor winding turns), the induced electromotive force waveform detected by the flux detection coil is as follows: Figure 5A As shown, its envelope is clearly not continuous and smooth.

[0050] Determine step S20: Based on the data values ​​and acquisition sequence number of the multiple induced electromotive forces, determine the induced electromotive force corresponding to each rotor slot under each magnetic pole;

[0051] In this step, due to the asymmetrical magnetic poles of the generator, the rotor slots are not evenly spaced. Furthermore, the multiple rotor slots under each magnetic pole can be numbered according to the same numbering rule; for example, using the center line of two adjacent magnetic poles as the axis of symmetry, the rotor slots are numbered sequentially from the center outwards. Figure 5A As shown, each magnetic pole has 8 rotor slots, which are numbered sequentially as 4, 3, 2, 1, 1′, 2′, 3′, and 4′ according to the direction of rotor rotation.

[0052] Judgment step S30: Compare the absolute values ​​of the induced electromotive forces corresponding to the corresponding rotor slots under different magnetic poles, and take the induced electromotive force with the smallest absolute value as the first data, and take the induced electromotive force with a non-small absolute value as the second data. Based on the difference between the absolute values ​​of the first data and the second data, determine whether the corresponding rotor slot under the corresponding magnetic pole corresponding to the first data has an inter-turn short circuit fault.

[0053] In this step, for example, combining Figure 5ATaking slot 4 as an example, the absolute values ​​of the induced electromotive forces (EMFs) corresponding to the four slots 4 under different magnetic poles can be compared. First, the one with the smallest absolute value is determined as the first data, and the induced EMFs of the other slots 4 are used as the second data. Then, the absolute difference between the first and second data is calculated, and the result is used to determine whether an inter-turn short circuit fault has occurred in the corresponding slot. It should be noted that if the number of second data is greater than one... Figure 5B (There are three values ​​in the middle). The absolute difference between the first data and each of the second data can be calculated successively, or the absolute difference between the first data and the second data with the largest absolute value can be calculated. Similarly, the same method can be used to determine and locate inter-turn short circuit faults in other rotor slots under different magnetic poles.

[0054] The technical solution of this embodiment analyzes the data values ​​and acquisition sequence numbers of multiple induced electromotive forces collected by the flux detection coil during one revolution of the generator rotor. This allows for the determination of the induced electromotive force corresponding to each rotor slot under each magnetic pole. Then, by comparing the absolute values ​​and calculating the differences between the induced electromotive forces corresponding to the rotor slots under different magnetic poles, the inter-turn short-circuit fault can be located. Furthermore, this method does not rely on rotor phase detection signals, is applicable to generators with asymmetrical magnetic pole structures, and is unaffected by load conditions and speed variations, enabling reliable location of inter-turn short-circuit faults under all operating conditions.

[0055] Further, in an optional embodiment, the determining step includes:

[0056] Step S21: Determine D / 2 positive peak voltages and D / 2 negative peak voltages based on the data values ​​of the plurality of induced electromotive forces, where D is the number of slots in the generator rotor;

[0057] In this step, since the induced electromotive force detected by the flux detection coil under the N magnetic pole (from the S pole to the N pole along the rotation direction of the motor rotor) is positive, and the induced electromotive force detected by the flux detection coil under the S magnetic pole (from the N pole to the S pole along the rotation direction of the motor rotor) is negative, there are a total of D / 2 positive peak voltages and D / 2 negative peak voltages, and each peak voltage corresponds to one rotor slot.

[0058] Step S22: Based on the data values ​​and acquisition sequence numbers of the D / 2 positive peak voltages, determine the induced electromotive force corresponding to each rotor slot under each N magnetic pole; and based on the data values ​​and acquisition sequence numbers of the D / 2 negative peak voltages, determine the induced electromotive force corresponding to each rotor slot under each S magnetic pole.

[0059] Furthermore, step S21 specifically includes:

[0060] The plurality of induced potentials are divided into p positive voltage data groups and p negative voltage data groups according to their data values, where p is the number of magnetic pole pairs;

[0061] For each positive voltage data set, the local maximum data is filtered out, and the largest D / (2p) data are determined from the local maximum data, and the largest D / (2p) data are taken as the positive peak voltage.

[0062] For each negative voltage data set, the local minimum data is filtered out, and the smallest D / (2p) data are determined from the local minimum data, and the smallest D / (2p) data are taken as the negative peak voltage.

[0063] Furthermore, local maximum data can be selected by traversing the positive voltage data group through a sliding window. For the current sliding window, if the middle data within the current sliding window is greater than any other data within the current sliding window, then the middle data within the current sliding window is determined as the local maximum data. The length of the sliding window is an odd number greater than 1. Correspondingly, local minimum data can be selected by traversing the negative voltage data group through a sliding window. For the current sliding window, if the middle data within the current sliding window is less than any other data within the current sliding window, then the middle data within the current sliding window is determined as the local minimum data.

[0064] In one specific embodiment, the length of the sliding window is, for example, 5, meaning that there are 5 sampling points (induced electromotive force) within one sliding window. The search method for local maxima is as follows: starting from the first sampling point of the induced electromotive force collected during one revolution of the rotor, the search proceeds backward. If the data of the i-th sampling point (i ≥ 3 and < N-2, where N is the number of sampling points) is greater than the data of the (i-1)-th and (i-2)-th sampling points, and also greater than the data of the (i+1)-th and (i+2)-th sampling points, then the data of the i-th sampling point is a local maxima; if the data of the 1st sampling point is greater than the data of the (N-1)-th and (N-2)-th sampling points, and also greater than the data of the 2nd and 3rd sampling points, then the data of the 1st sampling point is a local maxima; if the data of the 2nd ... then the data of the 2nd sampling point is a local maxima; if the data of the 2nd sampling point is greater than the data of the (N-1)-th and (N-2)-th sampling points, then the data of the 2nd sampling point is a local maxima; if the data of the 2nd sampling point is greater than the data of the (N-1 If the data at the second sampling point is greater than the data at the first sampling point and the (N-1)th sampling point, and also greater than the data at the third and fourth sampling points, then the data at the second sampling point is a local maximum. If the data at the (N-1)th sampling point is greater than the data at the (N-2)th and (N-3)th sampling points, and also greater than the data at the first and Nth sampling points, then the data at the (N-1)th sampling point is a local maximum. If the data at the Nth sampling point is greater than the data at the (N-1)th and (N-2)th sampling points, and also greater than the data at the first and second sampling points, then the data at the Nth sampling point is a local maximum.

[0065] Similarly, the search method for local minima is as follows: starting from the first sampling point of the induced electromotive force collected during one revolution of the rotor, the search proceeds backward. If the data of the i-th sampling point (i ≥ 3 and < N-2) is less than the data of the (i-1)-th and (i-2)-th sampling points, and less than the data of the (i+1)-th and (i+2)-th sampling points, then the data of the i-th point is a local minimum. If the data of the 1st sampling point is less than the data of the (N-1)-th and (N-2)-th sampling points, and less than the data of the 2nd and 3rd sampling points, then the data of the 1st sampling point is a local minimum. If the data of the 2nd sampling point is less than the data of the (N-1)-th and (N-2)-th sampling points, and less than the data of the 3rd and 4th sampling points, then the data of the 1st sampling point is a local minimum. If the data of a sample point is less than the data of the 1st and (N-1)th sample points, and less than the data of the 3rd and 4th sample points, then the data of the 2nd sample point is a local minimum. If the data of the (N-1)th sample point is less than the data of the (N-2)th and (N-3)th sample points, and less than the data of the Nth and 1st sample points, then the data of the (N-1)th sample point is a local minimum. If the data of the Nth sample point is less than the data of the (N-1)th and (N-2)th sample points, and less than the data of the 1st and 2nd sample points, then the data of the Nth sample point is a local minimum.

[0066] Further, in step S22, based on the data values ​​and acquisition sequence numbers of the D / 2 positive peak voltages, the induced electromotive force corresponding to each rotor slot under each N magnetic pole is determined, including:

[0067] For each group of D / (2p) positive peak voltages, sort them in ascending order, and then divide the sorted D / (2p) positive peak voltages into two groups in turn.

[0068] Using the center line of the corresponding N magnetic pole and its preceding S magnetic pole as the axis of symmetry, in order from the middle to both sides, the two positive peak voltages of each group are sequentially matched with the D / (2p) rotor slots under the corresponding N magnetic pole, and the rotor slots corresponding to the two positive peak voltages of each group are symmetrically distributed at both ends of the axis of symmetry. In addition, the rotor slots corresponding to the positive peak voltages with smaller acquisition numbers in the same group are located behind the rotor slots corresponding to the positive peak voltages with larger acquisition numbers along the rotor rotation direction of the motor.

[0069] Accordingly, in step S22, based on the data values ​​and acquisition sequence numbers of the D / 2 negative peak voltages, the induced electromotive force corresponding to each rotor slot under each S magnetic pole is determined, including:

[0070] For each group of D / (2p) negative peak voltages, sort them in descending order, and then divide the sorted D / (2p) negative peak voltages into two groups in sequence.

[0071] Using the center line of the corresponding S magnetic pole and its preceding N magnetic pole as the axis of symmetry, in order from the middle to both sides, the two negative peak voltages of each group are sequentially matched with the D / (2p) rotor slots under the corresponding S magnetic pole, and the rotor slots corresponding to the two negative peak voltages of each group are symmetrically distributed at both ends of the axis of symmetry. In addition, the rotor slots corresponding to the negative peak voltages with smaller acquisition numbers in the same group are located behind the rotor slots corresponding to the negative peak voltages with larger acquisition numbers along the rotor rotation direction of the motor.

[0072] The following is combined Figure 5ATaking a generator with 2 pairs of magnetic poles (i.e., p=2) and 32 rotor slots as an example, the method for determining the induced electromotive force (EMF) corresponding to each rotor slot is illustrated as follows: During the time interval of one rotor rotation (1s-1.04s), the waveform of the induced EMF detected contains 2 positive voltage data sets and 2 negative voltage data sets. For each positive voltage data set, the local maximum data is first selected, and then these local maximum data sets are sorted to determine the 8 largest data sets. These 8 largest data sets are taken as the positive peak voltages, and each of these 8 data sets corresponds one-to-one with the 8 rotor slots under the corresponding N magnetic pole. Then, these 8 data sets are arranged in ascending order, forming four groups of two. Furthermore, for the two data sets in the first group (the two smallest data sets), their corresponding rotor slots are determined to be rotor slots 1 and 1'; for the two data sets in the second group, their corresponding rotor slots are determined to be rotor slots 2 and 2'; and so on, until all four groups of data have their corresponding rotor slots determined. From the waveform diagram, these 8 data points correspond to the peaks of the induced electromotive force under the N magnetic pole in the positive waveform, from rotor slot 1 to rotor slot 4 and from rotor slot 1′ to rotor slot 4′. The induced electromotive force increases from the center line between the N magnetic pole and the previous S magnetic pole to both sides.

[0073] Similarly, for each negative voltage data group, the local minimum data is first selected, and then the eight smallest data points are determined by sorting these local minimum data points. These eight smallest data points are taken as negative peak voltages, and each of these eight data points corresponds one-to-one with the eight rotor slots under the corresponding S pole. Then, these eight smallest data points are arranged in descending order, forming four groups of two. Moreover, for the two data points in the first group (the two largest data points), their corresponding rotor slots are determined to be rotor slots 1 and 1'; for the two data points in the second group, their corresponding rotor slots are determined to be rotor slots 2 and 2'; and so on, until all four groups of data have their corresponding rotor slots determined. From the waveform diagram, these eight data points correspond to the peaks of the induced potential under the S pole in the negative waveform, from rotor slot 1 to rotor slot 4 and from rotor slot 1' to rotor slot 4', and the induced potential decreases from the center line between the S pole and the previous N pole to both sides.

[0074] Further, in the judgment step S30, determining whether an inter-turn short circuit fault has occurred in the corresponding rotor slot under the corresponding magnetic pole corresponding to the first data based on the absolute value difference between the first data and the second data includes:

[0075] Calculate the absolute difference between the first data and the second data;

[0076] Determine whether the absolute value difference is greater than a set value;

[0077] If the value is greater than the set value, it is determined that an inter-turn short circuit fault has occurred in the corresponding rotor slot under the magnetic pole corresponding to the first data.

[0078] In this embodiment, the set value is, for example, k*μ, where μ is a threshold value, specifically the amplitude of the electromotive force induced by a one-turn excitation winding coil on the flux detection coil. In practical applications, it can be determined by dividing the maximum value of the induced electromotive force of the corresponding rotor slot under each magnetic pole by the number of turns of that slot; k is a coefficient, for example, 0.5. Since the magnetomotive force generated by a one-turn coil will be consumed in the two air gaps, the induced electromotive force generated by the detection coil on a magnetic pole needs to be multiplied by a coefficient of 0.5.

[0079] The following is combined Figure 5A and Figure 5B To illustrate how to determine if a rotor inter-turn short-circuit fault has occurred: When the generator is operating normally (without a rotor inter-turn short-circuit fault), the induced electromotive force corresponding to the rotor slots under different magnetic poles is almost the same, such as... Figure 5A As shown, this indicates that the generator rotor is functioning normally. When a short-circuit fault occurs in rotor slot 4 under the previous N pole, the potential difference between the two N poles corresponding to rotor slot 4 is 19.2V - 17.9V = 1.3V, while the set value is 0.5 * 19.2V / 15 = 0.64V. The winding of rotor slot 4 has 15 turns. Since 1.3V > 0.64V, it can be determined that a short-circuit fault occurred in rotor slot 4 under the previous N pole.

[0080] The present invention also constructs a rotor inter-turn short-circuit fault location system for a generator, including a processor, which implements the steps of the above-described rotor inter-turn short-circuit fault location method for a generator when executing a stored computer program.

[0081] It should be understood that, in the embodiments of this application, the processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0082] Furthermore, since the processor can implement the steps of the rotor inter-turn short-circuit fault location method for any generator provided in the embodiments of the present invention when executing the computer program, the beneficial effects that the rotor inter-turn short-circuit fault location method for any generator provided in the embodiments of the present invention can achieve can be realized, as detailed in the preceding embodiments, and will not be repeated here.

[0083] The present invention also constructs a storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for locating rotor-to-turn short-circuit faults in a generator.

[0084] It should be understood that the storage medium may include various computer storage media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), magnetic disks, or optical disks. Furthermore, since the computer program stored in the storage medium, when executed, can implement the steps of the rotor inter-turn short-circuit fault location method for any of the generators provided in the embodiments of this invention, it can achieve the beneficial effects achievable by the rotor inter-turn short-circuit fault location method for any of the generators provided in the embodiments of this invention. Details can be found in the preceding embodiments and will not be repeated here.

[0085] Figure 6 This is a logical structure diagram of an embodiment of the rotor inter-turn short-circuit fault location system for the generator of the present invention. The rotor inter-turn short-circuit fault location system includes: a data acquisition module 10, a determination module 20, and a judgment module 30. The data acquisition module 10 is used to acquire multiple induced electromotive forces detected by the magnetic flux detection coil in real time during one rotation of the generator rotor. The magnetic flux detection coil is installed on the stator of the generator. The determination module 20 is used to determine the induced electromotive force corresponding to each rotor slot under each magnetic pole according to the data values ​​and acquisition sequence number of the multiple induced electromotive forces. The judgment module 30 is used to compare the absolute values ​​of the induced electromotive forces corresponding to the corresponding rotor slots under different magnetic poles, and take the induced electromotive force with the smallest absolute value as the first data, and take the induced electromotive force with a non-small absolute value as the second data. The difference between the absolute values ​​of the first data and the second data is used to determine whether an inter-turn short-circuit fault has occurred in the corresponding rotor slot under the corresponding magnetic pole corresponding to the first data.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any alterations, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for locating rotor-to-turn short-circuit faults in a generator, characterized in that, include: Data acquisition steps: During the time it takes for the generator rotor to rotate one revolution, multiple induced electromotive forces detected by the magnetic flux detection coil are acquired in real time, wherein the magnetic flux detection coil is installed on the stator of the generator. Determination steps: Based on the data values ​​and acquisition sequence numbers of the multiple induced electromotive forces, determine the induced electromotive force corresponding to each rotor slot under each magnetic pole; Judgment steps: Compare the absolute values ​​of the induced electromotive forces corresponding to the rotor slots under different magnetic poles, and take the induced electromotive force with the smallest absolute value as the first data, and take the induced electromotive force with a non-small absolute value as the second data. Then, determine whether an inter-turn short circuit fault has occurred in the corresponding rotor slot under the corresponding magnetic pole corresponding to the first data based on the difference between the absolute values ​​of the first data and the second data. This method does not rely on rotor phase detection signals and is applicable to generators with asymmetrical magnetic pole structures. In the judgment step, determining whether an inter-turn short circuit fault has occurred in the corresponding rotor slot under the corresponding magnetic pole corresponding to the first data based on the absolute value difference between the first data and the second data includes: Calculate the absolute difference between the first data and the second data; Determine whether the absolute value difference is greater than a set value; If the value is greater than the set value, it is determined that an inter-turn short circuit fault has occurred in the corresponding rotor slot under the magnetic pole corresponding to the first data. The determining step includes: Step S21: Determine D / 2 positive peak voltages and D / 2 negative peak voltages based on the data values ​​of the plurality of induced electromotive forces, where D is the number of slots in the generator rotor; Step S22: Based on the data values ​​and acquisition sequence numbers of the D / 2 positive peak voltages, determine the induced electromotive force corresponding to each rotor slot under each N magnetic pole; and based on the data values ​​and acquisition sequence numbers of the D / 2 negative peak voltages, determine the induced electromotive force corresponding to each rotor slot under each S magnetic pole. Step S21 includes: The plurality of induced potentials are divided into p positive voltage data groups and p negative voltage data groups according to their data values, where p is the number of magnetic pole pairs; For each positive voltage data set, the local maximum data is filtered out, and the largest D / 2p data are determined from the local maximum data, and the largest D / 2p data are taken as the positive peak voltage. For each negative voltage data group, the local minimum data is filtered out, and the smallest D / 2p data are determined from the local minimum data, and the smallest D / 2p data are taken as the negative peak voltage. In step S22, based on the data values ​​and acquisition sequence numbers of the D / 2 positive peak voltages, the induced electromotive force corresponding to each rotor slot under each N magnetic pole is determined, including: For each group of D / 2p positive peak voltages, sort them in ascending order, and then divide the sorted D / 2p positive peak voltages into two groups in sequence. Using the center line of the corresponding N magnetic pole and its preceding S magnetic pole as the axis of symmetry, in order from the middle to both sides, the two positive peak voltages of each group are sequentially matched with the D / 2p rotor slots under the corresponding N magnetic pole, and the rotor slots corresponding to the two positive peak voltages of each group are symmetrically distributed at both ends of the axis of symmetry. In addition, the rotor slots corresponding to the positive peak voltages with smaller acquisition numbers in the same group are in front of the rotor slots corresponding to the positive peak voltages with larger acquisition numbers along the rotor rotation direction of the motor.

2. The method for locating rotor inter-turn short-circuit faults in a generator according to claim 1, characterized in that, The filtering of local maximum data includes: The positive voltage data group is traversed by a sliding window. For the current sliding window, if the middle data in the current sliding window is greater than other data in the current sliding window, the middle data in the current sliding window is determined as the local maximum data. The length of the sliding window is an odd number greater than 1. The process of filtering out local minimum data includes: The negative voltage data set is traversed through a sliding window. If the middle data in the current sliding window is smaller than any other data in the current sliding window, then the middle data in the current sliding window is determined as the local minimum data.

3. The method for locating rotor inter-turn short-circuit faults in a generator according to claim 1, characterized in that, In step S22, based on the data values ​​and acquisition sequence numbers of the D / 2 negative peak voltages, the induced electromotive force corresponding to each rotor slot under each S magnetic pole is determined, including: For each group of D / 2p negative peak voltages, sort them in descending order, and then divide the sorted D / 2p negative peak voltages into two groups in sequence. Using the center line of the corresponding S magnetic pole and its preceding N magnetic pole as the axis of symmetry, in order from the middle to both sides, the two negative peak voltages of each group are sequentially matched with the D / 2p rotor slots under the corresponding S magnetic pole, and the rotor slots corresponding to the two negative peak voltages of each group are symmetrically distributed at both ends of the axis of symmetry. In addition, the rotor slots corresponding to the negative peak voltages with smaller acquisition numbers in the same group are in front of the rotor slots corresponding to the negative peak voltages with larger acquisition numbers along the rotor rotation direction of the motor.

4. A storage medium storing a computer program, characterized in that, When the computer program is executed, it implements the steps of the rotor inter-turn short-circuit fault location method for the generator according to any one of claims 1-3.

5. A rotor-to-turn short-circuit fault location system for a generator, comprising a processor, characterized in that, When the processor executes the stored computer program, it implements the steps of the rotor inter-turn short-circuit fault location method for the generator according to any one of claims 1-3.

6. A rotor-to-turn short-circuit fault location system for a generator, characterized in that, include: The acquisition module is used to acquire multiple induced electromotive forces detected by the magnetic flux detection coil in real time during the period of one rotation of the generator rotor, wherein the magnetic flux detection coil is installed on the stator of the generator. The determination module is used to determine the induced electromotive force corresponding to each rotor slot under each magnetic pole based on the data values ​​and acquisition sequence number of the multiple induced electromotive forces. The judgment module is used to compare the absolute values ​​of the induced electromotive forces corresponding to the corresponding rotor slots under different magnetic poles, and take the induced electromotive force with the smallest absolute value as the first data, and take the induced electromotive force with the non-smallest absolute value as the second data. Based on the difference between the absolute values ​​of the first data and the second data, it is determined whether the corresponding rotor slot under the corresponding magnetic pole corresponding to the first data has an inter-turn short circuit fault. The judgment module includes: The calculation unit is used to calculate the absolute value difference between the first data and the second data; The judgment unit is used to determine whether the absolute value difference is greater than a set value; The determining unit is used to determine that an inter-turn short circuit fault has occurred in the corresponding rotor slot under the magnetic pole corresponding to the first data if the absolute value difference is greater than the set value. Furthermore, this system does not rely on rotor phase detection signals and is suitable for generators with asymmetrical magnetic pole structures; The determining module includes: Used to determine D / 2 positive peak voltages and D / 2 negative peak voltages based on the data values ​​of the plurality of induced electromotive forces, where D is the number of slots in the generator rotor; This is used to determine the induced electromotive force corresponding to each rotor slot under each N magnetic pole based on the data values ​​and acquisition sequence numbers of the D / 2 positive peak voltages; and to determine the induced electromotive force corresponding to each rotor slot under each S magnetic pole based on the data values ​​and acquisition sequence numbers of the D / 2 negative peak voltages. The method for determining D / 2 positive peak voltages and D / 2 negative peak voltages based on the data values ​​of the plurality of induced electromotive forces, wherein D is the number of slots in the generator rotor, includes: The plurality of induced potentials are divided into p positive voltage data groups and p negative voltage data groups according to their data values, where p is the number of magnetic pole pairs; For each positive voltage data set, the local maximum data is filtered out, and the largest D / 2p data are determined from the local maximum data, and the largest D / 2p data are taken as the positive peak voltage. For each negative voltage data group, the local minimum data is filtered out, and the smallest D / 2p data are determined from the local minimum data, and the smallest D / 2p data are taken as the negative peak voltage. The method for determining the induced electromotive force corresponding to each rotor slot under each N magnetic pole based on the data values ​​and acquisition sequence numbers of the D / 2 positive peak voltages; and determining the induced electromotive force corresponding to each rotor slot under each S magnetic pole based on the data values ​​and acquisition sequence numbers of the D / 2 negative peak voltages includes: For each group of D / 2p positive peak voltages, sort them in ascending order, and then divide the sorted D / 2p positive peak voltages into two groups in sequence. Using the center line of the corresponding N magnetic pole and its preceding S magnetic pole as the axis of symmetry, in order from the middle to both sides, the two positive peak voltages of each group are sequentially matched with the D / 2p rotor slots under the corresponding N magnetic pole, and the rotor slots corresponding to the two positive peak voltages of each group are symmetrically distributed at both ends of the axis of symmetry. In addition, the rotor slots corresponding to the positive peak voltages with smaller acquisition numbers in the same group are in front of the rotor slots corresponding to the positive peak voltages with larger acquisition numbers along the rotor rotation direction of the motor.

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