Generator rotor turn-to-turn short circuit fault protection method, system and storage medium

Abstract

The present invention relates to a method, system and storage medium for protecting a generator from a rotor short-circuit fault. The method comprises: collecting the induced potential detected by the magnetic flux detection coil in real time and storing it in an induced potential data group in sequence; intercepting multiple induced potentials in a specific period from the induced potential data group, and dividing the intercepted multiple induced potentials into 2p groups, and calculating the data sum of the induced potentials at corresponding positions in each group to obtain multiple superimposed data, and calculating the effective value of the multiple superimposed data; determining whether a rotor short-circuit fault occurs according to the effective value, and generating a protection signal when a rotor short-circuit fault occurs. The technical solution of the present invention can realize reliable and sensitive protection of rotor short-circuit faults under all working conditions, and is completely unaffected by the operating state of the generator, that is, it is applicable to both no-load and load operation, and also to generators with asymmetric rotor magnetic poles.

Description

Technical Field

[0001] The present invention relates to the field of electric power systems, and in particular to a method, system and storage medium for protecting a generator from rotor inter-turn short-circuit faults. Background Art

[0002] Rotor winding interturn short circuit is a common electrical fault of synchronous generators. The basic principle of existing fault online monitoring devices is as follows: Figure 1 As shown in the figure, there are multiple rotor slots symmetrically distributed between the magnetic pole pairs, and the rotor winding (excitation winding) is embedded in the rotor slot. The rotor main magnetic field is generated by all the rotor coils. Although the short circuit between the rotor winding turns will affect the intensity of the main magnetic flux, it is not easy to measure because of its small proportion. The leakage flux is linked to the rotor winding of each slot, and its size is proportional to the number of rotor coil turns in the slot, which can directly reflect the change of the number of rotor coil turns in each slot. Therefore, the existing online fault monitoring device usually fixes the flux detection coil on the stator and makes it as close to the rotor core as possible. The flux detection coil can detect the radial component and tangential component of the leakage flux during the rotation of the rotor, and differentiate it. By analyzing the differential waveform, it can be determined whether the generator has a short circuit fault between the rotor winding turns.

[0003] Combine the following Figure 2 Explain the principle of the flux detection coil method when the generator is running at no load: X1 is Figure 1 The rotor winding in (after expansion), the leakage flux corresponding to the rotor winding in each rotor slot is shown as X2. Moreover, if there is no inter-turn short circuit in the rotor winding, the peak envelope X41, X42 of the induced voltage X3 corresponding to each rotor slot is continuous and smooth, and the number and sequence of its peaks correspond to the rotor slot one by one. When there is an inter-turn short circuit in a certain slot coil of the rotor winding, the leakage flux linked to the slot will be reduced, and the potential induced on the flux detection coil will be reduced accordingly. The peak at the corresponding position in the induced potential waveform leaves the envelope and shrinks and shortens, indicating that there is an inter-turn short circuit fault in the rotor winding in the corresponding slot.

[0004] However, the detection method adopted by the above-mentioned fault online monitoring device is most suitable for monitoring the fault of the generator rotor winding when it is not loaded. It is greatly affected by the operating state of the generator. In actual operation, the air gap magnetic field distortion caused by the armature reaction and the influence of factors such as core saturation make it difficult to accurately judge the inter-turn short circuit. In addition, the rotor windings of many generators in the project are asymmetric magnetic pole structures, such as Figure 3 As shown, the asymmetry of the rotor poles makes the conventional inspection method based on the envelope of the flux detection coil ineffective. 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 protecting the rotor turn-to-turn short-circuit fault of a generator in view of the defects that the existing detection method is greatly affected by the operating state of the generator and does not use a generator with an asymmetric magnetic pole structure.

[0006] The technical solution adopted by the present invention to solve the technical problem is: constructing a rotor turn-to-turn short-circuit fault protection method for a generator, comprising:

[0007] Acquisition step: real-time acquisition of the induced potential detected by the magnetic flux detection coil, and sequential storage of the induced potential data group; wherein the magnetic flux detection coil is installed on the stator of the generator;

[0008] Processing step: extracting multiple induced potentials in a specific time period from the induced potential data group, and dividing the extracted multiple induced potentials into 2p groups, and calculating the data sum of the induced potentials at corresponding positions in each group to obtain multiple superposition data, and calculating the effective value of the multiple superposition data, wherein the specific time period is greater than or equal to the rotor rotation period of the generator, and p is the number of magnetic pole pairs of the generator;

[0009] Judgment step: determining whether a rotor turn-to-turn short circuit fault occurs according to the effective value, and generating a protection signal when a rotor turn-to-turn short circuit fault occurs.

[0010] Preferably, the processing step comprises:

[0011] Step S21, extracting a plurality of induced potentials in a specific period of time from the induced potential data group, and dividing the extracted plurality of induced potentials into 2p groups according to a plurality of different grouping methods, wherein the data length of each group in different grouping methods is different;

[0012] Step S22, for each grouping mode, respectively calculating the sum of the induced potential data at the corresponding positions in each group to obtain a plurality of superimposed data corresponding to the corresponding grouping mode, and calculating the effective value of the plurality of superimposed data corresponding to each grouping mode;

[0013] Step S23, determining the smallest valid value among the valid values ​​corresponding to the plurality of grouping modes;

[0014] Furthermore, determining whether a rotor turn-to-turn short circuit fault occurs according to the effective value includes:

[0015] Whether a rotor turn-to-turn short circuit fault occurs is determined according to the minimum effective value.

[0016] Preferably, the step S21 includes:

[0017] Extracting the induced potential within a specific time period from the induced potential data group to obtain N1 induced potentials, wherein N1=0.02pf+2p, and f is the sampling frequency of the magnetic flux detection coil;

[0018] The intercepted N1 induced potentials are divided into 2p groups according to three different grouping methods. In the first grouping method, the data length of each group is 0.01f, and the remaining 2p data are discarded; in the second grouping method, the data length of each group is 0.01f+1; in the third grouping method, the data length of each group is 0.01f-1, and the remaining 4p data are discarded.

[0019] Preferably, the step S21 includes:

[0020] The induced potential within a specific time period is intercepted from the induced potential data group to obtain N2 induced potentials, wherein N2=0.02pf+4p, and f is the sampling frequency of the magnetic flux detection coil;

[0021] The intercepted N2 induced potentials are divided into 2p groups according to five different grouping methods. In the first grouping method, the data length of each group is 0.01f, and the remaining 4p data are discarded; in the second grouping method, the data length of each group is 0.01f+1, and the remaining 2p data are discarded; in the third grouping method, the data length of each group is 0.01f-1, and the remaining 6p data are discarded; in the fourth grouping method, the data length of each group is 0.01f+2; in the fifth grouping method, the data length of each group is 0.01f-2, and the remaining 8p data are discarded.

[0022] Preferably, the step S21 includes:

[0023] The induced potential within a specific time period is intercepted from the induced potential data group to obtain N3 induced potentials, wherein N3=0.02pf+6p, and f is the sampling frequency of the magnetic flux detection coil;

[0024] The intercepted N3 induced potentials are divided into 2p groups according to seven different grouping methods, among which, in the first grouping method, the data length of each group is 0.01f, and the remaining 6p data are discarded; in the second grouping method, the data length of each group is 0.01f+1, and the remaining 4p data are discarded; in the third grouping method, the data length of each group is 0.01f-1, and the remaining 8p data are discarded; in the fourth grouping method, the data length of each group is 0.01f+2, and the remaining 2p data are discarded; in the fifth grouping method, the data length of each group is 0.01f-2, and the remaining 10p data are discarded; in the sixth grouping method, the data length of each group is 0.01f+3; in the fifth grouping method, the data length of each group is 0.01f-3, and the remaining 12p data are discarded.

[0025] Preferably, determining whether a rotor turn-to-turn short circuit fault occurs according to the effective value includes:

[0026] It is determined whether the effective value is greater than a set value. If so, it is determined that a rotor turn-to-turn short circuit fault has occurred.

[0027] Preferably, the calculating the effective values ​​of the plurality of superposition data comprises:

[0028] The sum of squares of the plurality of superimposed data is calculated, and a square root operation is performed on the sum of squares, and the square root operation result is used as a valid value.

[0029] The present invention also constructs a storage medium storing a computer program, which implements the steps of the above-mentioned method for protecting the generator from rotor inter-turn short-circuit fault when executed.

[0030] The present invention also constructs a generator rotor turn-to-turn short-circuit fault protection system, comprising a processor, wherein the processor implements the steps of the generator rotor turn-to-turn short-circuit fault protection method described above when executing a stored computer program.

[0031] The present invention also constructs a generator rotor turn-to-turn short-circuit fault protection system, comprising:

[0032] A collection module, used for collecting the induced potential detected by the magnetic flux detection coil in real time and storing it in sequence into an induced potential data group; wherein the magnetic flux detection coil is installed on the stator of the generator;

[0033] a processing module, configured to extract multiple induced potentials in a specific time period from the induced potential data group, divide the extracted multiple induced potentials into 2p groups, calculate the data sum of the induced potentials at corresponding positions in each group to obtain multiple superposition data, and calculate the effective value of the multiple superposition data, wherein the specific time period is greater than or equal to the rotor rotation period of the generator, and p is the number of magnetic pole pairs of the generator;

[0034] The judgment module is used to determine whether a rotor turn-to-turn short circuit fault occurs according to the effective value, and generate a protection signal when a rotor turn-to-turn short circuit fault occurs.

[0035] The technical solution provided by the present invention intercepts and groups the induced potential detected in real time by the flux detection coil, then superimposes the data of each group and calculates the effective value, and finally determines whether a rotor turn-to-turn short circuit fault occurs based on the effective value. It can achieve reliable and sensitive protection against rotor turn-to-turn short circuit faults under all working conditions, and is completely unaffected by the operating state of the generator, that is, it is applicable to both no-load and load operation, and also to generators with asymmetric rotor magnetic poles. Therefore, this plays an important role in ensuring the power generation safety of the unit and improving the operating reliability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 work. In the drawings:

[0037] Figure 1 It is a schematic diagram of the structure of the rotor winding with a symmetrical magnetic pole structure;

[0038] Figure 2 It is a schematic diagram of the principle of the online fault monitoring device of the prior art;

[0039] Figure 3 It is a schematic diagram of the structure of the rotor winding with an asymmetric magnetic pole structure;

[0040] Figure 4 It is a flow chart of Embodiment 1 of the method for protecting the generator from rotor inter-turn short circuit fault of the present invention;

[0041] Figure 5 It is the waveform diagram of the induced potential of the rotor with asymmetric magnetic pole structure when the generator is operating normally;

[0042] Figure 6 yes Figure 1 Flow chart of the first embodiment of the processing step S20;

[0043] FIG. 7A to FIG. 7GThey are the waveform diagrams of superimposed data under seven grouping methods;

[0044] Figure 8 It is a logical structure diagram of the first embodiment of the rotor turn-to-turn short-circuit fault protection of the generator of the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] Figure 4 1 is a flow chart of a first embodiment of a method for protecting a generator from a rotor turn-to-turn short circuit fault according to the present invention. The method for protecting a generator from a rotor turn-to-turn short circuit fault according to the present invention comprises the following steps:

[0047] Acquisition step S10: real-time acquisition of the induced potential detected by the magnetic flux detection coil, and sequential storage thereof into an induced potential data group; wherein the magnetic flux detection coil is installed on the stator of the generator;

[0048] In this step, when a certain magnetic pole asymmetric generator is operating normally (without rotor winding interturn short circuit fault), the induced potential waveform of the flux detection coil is as follows: Figure 5 As shown, it is obvious that its envelope is not continuous and smooth.

[0049] Processing step S20: extracting a plurality of induced potentials in a specific period of time from the induced potential data group, and dividing the extracted plurality of induced potentials into 2p groups, and calculating the data sum of the induced potentials at corresponding positions in each group to obtain a plurality of superimposed data, and calculating the effective value of the plurality of superimposed data, wherein the specific period of time is greater than or equal to the rotor rotation period of the generator, and p is the number of magnetic pole pairs of the generator;

[0050] In this step, when intercepting the induced potential, it can be intercepted from the moment when the positive and negative voltages are converted, and the intercepted time period is greater than or equal to the rotor rotation period of the generator, that is, it covers the data detected by the flux detection coil during one rotation of the generator rotor.

[0051] When the intercepted data are grouped, since p is the number of magnetic pole pairs, and the induced potential detected by the flux detection coil under the N pole is positive, and the induced potential detected by the flux detection coil under the S pole is negative, so, if there are 2 pairs of magnetic poles (that is, p=2), there are two N poles and S poles, for each N pole, there is a positive voltage in the detected induced potential waveform, and for each S pole, there is a negative voltage in the detected induced potential waveform, so the multiple intercepted induced potentials are divided into 2p groups.

[0052] After obtaining the data of 2p groups, the superimposed data is calculated first, that is, the data of the corresponding position in each group is added, for example, the first data in each group is added, the second data in each group is added, and so on, until the last data in each group is added, so as to obtain a group of superimposed data, and then the effective value of the multiple superimposed data is calculated. Ideally, if the generator operates normally (no rotor winding inter-turn short circuit fault occurs), because the positive voltage at the corresponding position just offsets the negative voltage, the multiple superimposed data obtained are all 0, and the calculated effective value is also 0; if the generator has a rotor winding inter-turn short circuit fault, because the positive voltage and negative voltage at the corresponding position cannot completely offset each other, the superimposed data corresponding to the position is a value with a relatively large absolute value, and the calculated effective value is also a relatively large value. Of course, in other embodiments, it is not necessary to perform calculations on every data in each group, but only select part of the data for calculations. For example, only the fifth, tenth, ..., and so on in each group are added. In this way, the amount of calculation can be reduced and the response speed of fault protection can be improved.

[0053] Determining step S30: determining whether a rotor turn-to-turn short circuit fault occurs according to the effective value, and generating a protection signal when a rotor turn-to-turn short circuit fault occurs.

[0054] The technical solution of this embodiment intercepts and groups the induced potential detected in real time by the flux detection coil, then superimposes the data of each group and calculates the effective value, and finally determines whether a rotor turn-to-turn short circuit fault occurs based on the effective value. It can achieve reliable and sensitive protection against rotor turn-to-turn short circuit faults under all working conditions, and is completely unaffected by the operating state of the generator, that is, it is applicable to both no-load and load operation, and also to generators with asymmetric rotor poles. Therefore, this plays an important role in ensuring the power generation safety of the unit and improving the operating reliability of the unit.

[0055] Further, in the processing step S20, the effective value may be calculated in the following manner: a sum of squares of the plurality of superimposed data is calculated, and a square root operation is performed on the sum of squares, and the square root operation result is used as the effective value.

[0056] Further, in the judgment step S30, whether a rotor turn-to-turn short circuit fault occurs can be determined in the following manner: determine whether the effective value is greater than a set value, and if so, determine that a rotor turn-to-turn short circuit fault occurs; if not, determine that a rotor turn-to-turn short circuit fault does not occur.

[0057] Figure 6 yes Figure 1 The flowchart of the first embodiment of the processing step S20 is shown in FIG. 1 . In this embodiment, step S20 includes:

[0058] Step S21, extracting a plurality of induced potentials in a specific period of time from the induced potential data group, and dividing the extracted plurality of induced potentials into 2p groups according to a plurality of different grouping methods, wherein the data length of each group in different grouping methods is different;

[0059] Step S22, for each grouping mode, respectively calculating the sum of the induced potential data at the corresponding positions in each group to obtain a plurality of superimposed data corresponding to the corresponding grouping mode, and calculating the effective value of the plurality of superimposed data corresponding to each grouping mode;

[0060] Step S23, determining the smallest valid value among the valid values ​​corresponding to the plurality of grouping modes;

[0061] Moreover, in the judgment step S30, whether a rotor turn-to-turn short circuit fault occurs may be determined in the following manner: whether a rotor turn-to-turn short circuit fault occurs is determined based on the minimum effective value.

[0062] Regarding this embodiment, it should be noted that in actual operation of the generator, the rotor does not necessarily strictly run at the synchronous speed in real time, but has a slight difference from the synchronous speed. When the actual speed is less than the synchronous speed, the flux detection coil takes more time to rotate one magnetic pole; when the actual speed is greater than the synchronous speed, the flux detection coil takes less time to rotate one magnetic pole. In this way, when grouping data, it is possible that the data that should belong to this group is grouped into the next group, or the data that should belong to the next group is grouped into this group.

[0063] Based on this, when grouping the intercepted data, this embodiment can group them according to a variety of different grouping methods, and each grouping method corresponds to an actual possible speed, that is, the data length of each group in different grouping methods is different. Then, the 2p groups of data divided in different ways can be obtained, and then the corresponding effective values ​​of each grouping method are calculated respectively for each grouping method, so that the effective values ​​corresponding to the multiple grouping methods can be obtained, and finally the smallest effective value is determined from the multiple effective values, and then it is considered that the speed corresponding to the grouping method corresponding to the smallest effective value is closest to the actual speed of the generator rotor. Therefore, the technical solution of this embodiment solves the error caused by the slight difference in speed by correcting the translation waveform, and significantly improves the sensitivity of the protection.

[0064] Furthermore, when collecting the detected induced potential from the flux detection coil, since the working frequency of the generator is 50Hz, the period is 0.02s, and the sampling frequency of the flux detection coil is f, and the sampling frequency f is generally not less than 50k / s, then the number of sampling points corresponding to a pair of magnetic poles is 0.02f, and the generator rotor of p pairs of magnetic poles rotates one circle, then 0.02pf data can be collected. In addition, considering the influence of the actual rotor speed, a few more data can be sampled.

[0065] In addition, although the rotor speed of the generator may be greater than or less than the synchronous speed, due to the frequency regulation measures when the generator is running, the deviation of the actual speed relative to the synchronous speed will not be too large. Therefore, in practical applications, the degree of deviation of the rotor speed can be combined to select a suitable number of grouping methods. For example, if the deviation between the actual rotor speed and the synchronous speed is small, it can be grouped according to three different grouping methods; if the deviation between the actual rotor speed and the synchronous speed is large, it can be grouped according to seven different grouping methods, and so on.

[0066] In a specific embodiment, for the case where the deviation between the actual speed of the generator rotor and the synchronous speed is small, the intercepted data can be grouped in three different grouping modes. Specifically, step S21 includes:

[0067] Extracting the induced potential within a specific time period from the induced potential data group to obtain N1 induced potentials, wherein N1=0.02pf+2p, and f is the sampling frequency of the magnetic flux detection coil;

[0068] The intercepted N1 induced potentials are divided into 2p groups according to three different grouping methods. In the first grouping method, the data length of each group is 0.01f, and the remaining 2p data are discarded; in the second grouping method, the data length of each group is 0.01f+1; in the third grouping method, the data length of each group is 0.01f-1, and the remaining 4p data are discarded.

[0069] In a specific embodiment, for the case where the actual rotation speed of the generator rotor deviates slightly from the synchronous rotation speed, the intercepted data may be grouped in five different grouping modes. Specifically, step S21 includes:

[0070] The induced potential within a specific time period is intercepted from the induced potential data group to obtain N2 induced potentials, wherein N2=0.02pf+4p, and f is the sampling frequency of the magnetic flux detection coil;

[0071] The intercepted N2 induced potentials are divided into 2p groups according to five different grouping methods. In the first grouping method, the data length of each group is 0.01f, and the remaining 4p data are discarded; in the second grouping method, the data length of each group is 0.01f+1, and the remaining 2p data are discarded; in the third grouping method, the data length of each group is 0.01f-1, and the remaining 6p data are discarded; in the fourth grouping method, the data length of each group is 0.01f+2; in the fifth grouping method, the data length of each group is 0.01f-2, and the remaining 8p data are discarded.

[0072] In a specific embodiment, in case that the actual rotation speed of the generator rotor deviates greatly from the synchronous rotation speed, the intercepted data may be grouped in seven different grouping modes. Specifically, step S21 includes:

[0073] The induced potential within a specific time period is intercepted from the induced potential data group to obtain N3 induced potentials, wherein N3=0.02pf+6p, and f is the sampling frequency of the magnetic flux detection coil;

[0074] The intercepted N3 induced potentials are divided into 2p groups according to seven different grouping methods, among which, in the first grouping method, the data length of each group is 0.01f, and the remaining 6p data are discarded; in the second grouping method, the data length of each group is 0.01f+1, and the remaining 4p data are discarded; in the third grouping method, the data length of each group is 0.01f-1, and the remaining 8p data are discarded; in the fourth grouping method, the data length of each group is 0.01f+2, and the remaining 2p data are discarded; in the fifth grouping method, the data length of each group is 0.01f-2, and the remaining 10p data are discarded; in the sixth grouping method, the data length of each group is 0.01f+3; in the fifth grouping method, the data length of each group is 0.01f-3, and the remaining 12p data are discarded.

[0075] The following takes the intercepted data grouped in seven different ways as an example to illustrate the fault judgment process:

[0076] First, 0.02pf+6p data are intercepted from the induced potential data group, that is, the data within the period of one rotation of the rotor is collected, and 6p more data are sampled. Then, starting from the first point, the data is divided into 2p groups according to the following seven methods:

[0077] Method 1: the length of each data set is 0.01f, and the remaining 6p points are discarded;

[0078] Method 2: the length of each data set is 0.01f+1, and the remaining 4p points are discarded;

[0079] Method 3: the length of each data set is 0.01f+2, and the remaining 2p points are discarded;

[0080] Mode 4, the length of each data set is 0.01f+3;

[0081] Method 5, the length of each data set is 0.01f-1, and the remaining 8p points are discarded;

[0082] Method 6, the length of each data set is 0.01f-2, and the remaining 10p points are discarded;

[0083] Method 7, the length of each data set is 0.01f-3, and the remaining 12p points are discarded;.

[0084] In the above seven grouping methods, the length of the sampled data points of each group can be 0.01f, 0.01f+1 or 0.01f-1, 0.01f+2 or 0.01f-2, or 0.01f+3 or 0.01f-3. The above grouping conditions are sufficient for the actual site (the degree to which the rotor speed deviates from the synchronous speed).

[0085] After the groups are divided according to the above grouping methods, for each grouping method, the data of the 2p groups under the grouping method can be superimposed, that is, the first data of each group is added, the second data of each group is added, and so on, and the superimposed data under seven grouping methods are obtained in turn. The waveforms of the superimposed data corresponding to the above seven grouping methods are as follows FIG. 7A to FIG. 7G Then, the effective values ​​of the superimposed data under the seven modes are calculated respectively, and seven effective values ​​are obtained. Then the minimum value among the seven effective values ​​is found. Obviously, Figure 7C The effective value under the corresponding grouping method (method 3) is the smallest.

[0086] Finally, the minimum value is compared with the set value. If it is greater than the set value, it is considered that a rotor turn-to-turn short circuit fault has occurred. Otherwise, it is considered that a rotor turn-to-turn short circuit fault has not occurred. In addition, regarding the set value, it can be K*D, where D is the minimum effective value calculated by the above method for the induced potential of the collected flux detection coil under no-load, 50% load and full load conditions during normal operation; K is a coefficient, for example, 1.2. Assuming that the calculated minimum effective value is 0.05V under no-load, 50% load and full load conditions during actual normal operation, then the set value is 1.2×0.05V=0.06V. Through simulation, it can be seen that when a 1-turn short circuit fault occurs in the first pole, the minimum effective value is 0.39V, and the protection sensitivity coefficient is 0.39 / 0.06=6.5, and the protection can act sensitively.

[0087] The technical solution of this embodiment can reduce the calculation deviation caused by the slight difference between the rotor speed and the synchronous speed of the generator. Field tests and simulations show that the minimum effective value during normal operation is very small. When a short circuit fault occurs in one turn of the rotor winding, the minimum effective value is much larger than the set value, and the protection can act reliably and sensitively.

[0088] Figure 8 The present invention is a logical structure diagram of a first embodiment of a rotor turn-to-turn short-circuit fault protection system for a generator of the present invention. The rotor turn-to-turn short-circuit fault protection system of the embodiment comprises: an acquisition module 10, a processing module 20, and a judgment module 30, wherein the acquisition module 10 is used to acquire the induced potential detected by the flux detection coil in real time, and store it in an induced potential data group in sequence; wherein the flux detection coil is installed on the stator of the generator; the processing module 20 is used to intercept multiple induced potentials in a specific time period from the induced potential data group, and divide the intercepted multiple induced potentials into 2p groups, and calculate the data and of the induced potentials at corresponding positions in each group to obtain multiple superimposed data, and calculate the effective value of the multiple superimposed data, wherein the specific time period is greater than or equal to the rotor rotation period of the generator, and p is the number of magnetic pole pairs of the generator; the judgment module 30 is used to determine whether a rotor turn-to-turn short-circuit fault occurs according to the effective value, and generate a protection signal when a rotor turn-to-turn short-circuit fault occurs.

[0089] The present invention also constructs a rotor turn-to-turn short-circuit fault protection system for a generator. The compensation voltage determination system includes a processor, and the processor implements the steps of the method described above when executing a computer program.

[0090] It should be understood that in the embodiments of the present application, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processor may be a microprocessor or any conventional processor, etc.

[0091] Moreover, since the processor can implement the steps of any method for protecting the rotor turn-to-turn short-circuit fault of a generator provided in the embodiments of the present invention when executing the computer program, the beneficial effects that can be achieved by any method for protecting the rotor turn-to-turn short-circuit fault of a generator provided in the embodiments of the present invention can be achieved. Please refer to the previous embodiments for details and will not be repeated here.

[0092] The present invention also constructs a storage medium, which stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned method for protecting the generator from rotor inter-turn short-circuit fault are implemented.

[0093] It should be understood that the storage medium may include: a U disk, a mobile hard disk, a read-only memory (ROM), a magnetic disk or an optical disk, and other computer storage media that can store program codes. Moreover, since the computer program stored in the storage medium can implement the steps of any of the generator rotor inter-turn short-circuit fault protection methods provided in the embodiments of the present invention when executed, the beneficial effects that can be achieved by any of the generator rotor inter-turn short-circuit fault protection methods provided in the embodiments of the present invention can be achieved, as detailed in the previous embodiments, which will not be repeated here.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A method for protecting a generator from a rotor turn-to-turn short circuit fault, characterized in that: include: Acquisition step: real-time acquisition of the induced potential detected by the magnetic flux detection coil, and sequential storage of the induced potential data group; wherein the magnetic flux detection coil is installed on the stator of the generator; Processing step: extracting multiple induced potentials in a specific time period from the induced potential data group, and dividing the extracted multiple induced potentials into 2p groups, and calculating the data sum of the induced potentials at corresponding positions in each group to obtain multiple superposition data, and calculating the effective value of the multiple superposition data, wherein the specific time period is greater than or equal to the rotor rotation period of the generator, and p is the number of magnetic pole pairs of the generator; Determining step: determining whether a rotor turn-to-turn short circuit fault occurs according to the effective value, and generating a protection signal when a rotor turn-to-turn short circuit fault occurs; The processing steps include: Step S21, extracting a plurality of induced potentials in a specific period of time from the induced potential data group, and dividing the extracted plurality of induced potentials into 2p groups according to a plurality of different grouping methods, wherein the data length of each group in different grouping methods is different; Step S22, for each grouping mode, respectively calculating the sum of the induced potential data at the corresponding positions in each group to obtain a plurality of superimposed data corresponding to the corresponding grouping mode, and calculating the effective value of the plurality of superimposed data corresponding to each grouping mode; Step S23, determining the smallest valid value among the valid values ​​corresponding to the plurality of grouping modes; Furthermore, determining whether a rotor turn-to-turn short circuit fault occurs according to the effective value includes: Whether a rotor turn-to-turn short circuit fault occurs is determined according to the minimum effective value.

2. The method for protecting a generator from a rotor turn-to-turn short-circuit fault according to claim 1, characterized in that: The step S21 comprises: The induced potential within a specific time period is intercepted from the induced potential data group to obtain N1 induced potentials, wherein N1=0.02pf+2p, and f is the sampling frequency of the magnetic flux detection coil; The intercepted N1 induced potentials are divided into 2p groups according to three different grouping methods. In the first grouping method, the data length of each group is 0.01f, and the remaining 2p data are discarded; in the second grouping method, the data length of each group is 0.01f+1; in the third grouping method, the data length of each group is 0.01f-1, and the remaining 4p data are discarded.

3. The method for protecting a generator from a rotor turn-to-turn short-circuit fault according to claim 1, characterized in that: The step S21 comprises: The induced potential within a specific time period is intercepted from the induced potential data group to obtain N2 induced potentials, wherein N2=0.02pf+4p, and f is the sampling frequency of the magnetic flux detection coil; The intercepted N2 induced potentials are divided into 2p groups according to five different grouping methods. In the first grouping method, the data length of each group is 0.01f, and the remaining 4p data are discarded; in the second grouping method, the data length of each group is 0.01f+1, and the remaining 2p data are discarded; in the third grouping method, the data length of each group is 0.01f-1, and the remaining 6p data are discarded; in the fourth grouping method, the data length of each group is 0.01f+2; in the fifth grouping method, the data length of each group is 0.01f-2, and the remaining 8p data are discarded.

4. The method for protecting a generator from a rotor turn-to-turn short-circuit fault according to claim 1, characterized in that: The step S21 comprises: The induced potential within a specific time period is intercepted from the induced potential data group to obtain N3 induced potentials, wherein N3=0.02pf+6p, and f is the sampling frequency of the magnetic flux detection coil; The intercepted N3 induced potentials are divided into 2p groups according to seven different grouping methods, among which, in the first grouping method, the data length of each group is 0.01f, and the remaining 6p data are discarded; in the second grouping method, the data length of each group is 0.01f+1, and the remaining 4p data are discarded; in the third grouping method, the data length of each group is 0.01f-1, and the remaining 8p data are discarded; in the fourth grouping method, the data length of each group is 0.01f+2, and the remaining 2p data are discarded; in the fifth grouping method, the data length of each group is 0.01f-2, and the remaining 10p data are discarded; in the sixth grouping method, the data length of each group is 0.01f+3; in the fifth grouping method, the data length of each group is 0.01f-3, and the remaining 12p data are discarded.

5. The method for protecting a generator from a rotor turn-to-turn short circuit fault according to any one of claims 1 to 4, characterized in that: Determining whether a rotor turn-to-turn short circuit fault occurs according to the effective value includes: It is determined whether the effective value is greater than a set value. If so, it is determined that a rotor turn-to-turn short circuit fault has occurred.

6. The method for protecting a generator from a rotor turn-to-turn short-circuit fault according to claim 1, characterized in that: The calculating the effective values ​​of the plurality of superposition data comprises: The sum of squares of the plurality of superimposed data is calculated, and a square root operation is performed on the sum of squares, and the square root operation result is used as a valid value.

7. A storage medium storing a computer program, characterized in that: When the computer program is executed, the steps of the method for protecting the generator from rotor turn-to-turn short-circuit faults are implemented.

8. A generator rotor turn-to-turn short-circuit fault protection system, comprising a processor, characterized in that: The processor implements the steps of the method for protecting the generator from rotor turn-to-turn short-circuit faults as described in any one of claims 1 to 6 when executing the stored computer program.

9. A generator rotor turn-to-turn short circuit fault protection system, characterized in that: include: A collection module, used for collecting the induced potential detected by the magnetic flux detection coil in real time and storing it in sequence into an induced potential data group; wherein the magnetic flux detection coil is installed on the stator of the generator; A processing module, used for intercepting a plurality of induced potentials in a specific time period from the induced potential data group, and dividing the intercepted plurality of induced potentials into 2p groups, and respectively calculating the data sum of the induced potentials at corresponding positions in each group for each grouping method, so as to obtain a plurality of superimposed data corresponding to the corresponding grouping method, and calculating the effective value of the plurality of superimposed data corresponding to each grouping method, and determining the minimum effective value among the effective values ​​respectively corresponding to the plurality of grouping methods, wherein the specific time period is greater than or equal to the rotor rotation period of the generator, p is the number of magnetic pole pairs of the generator, and the data length of each group in different grouping methods is different; The judgment module is used to determine whether a rotor turn-to-turn short circuit fault occurs according to the minimum effective value, and generate a protection signal when a rotor turn-to-turn short circuit fault occurs.

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