Electrical fault detection method, device and equipment based on multi-pole detection coil

Abstract

The invention relates to an electrical fault detection method, device and equipment based on a multi-magnetic-pole detection coil, and the method comprises the steps: obtaining the number of pole pairs of a brushless exciter, determining the number of detection coils according to the number of pole pairs of the brushless exciter, and setting a plurality of detection coils on a stator magnetic pole of the brushless exciter based on the number of detection coils; under the condition that the number of pole pairs of the brushless exciter meets a preset symmetric distribution condition, calculating a weighting coefficient of each detection coil, and obtaining a synthetic voltage according to the weighting coefficient and the port voltage of each detection coil; and analyzing the spectral characteristics of the synthesized voltage to obtain a spectral characteristic analysis result, and obtaining an electrical fault detection result according to the spectral characteristic analysis result. Therefore, the problem that the diode open-circuit fault and the armature winding internal short-circuit fault cannot be clearly distinguished through the harmonic characteristics in the prior art is solved, and the brushless exciter electrical fault detection effect is improved.

Description

Technical Field

[0001] The present invention relates to the field of electrical engineering technology, and in particular to an electrical fault detection method, device and equipment based on a multi-pole detection coil. Background Art

[0002] Large synchronous generators are an important component of the power grid and play a key role in power transmission and stable system operation. The excitation system is a key equipment of large synchronous generators. Brushless exciters are very prone to failure in long-term high-intensity working environments. Fault detection of brushless exciters has become a very important part.

[0003] In the related art, a fault detection method based on the harmonic characteristics of the port voltage of two magnetic pole detection coils in series is used to detect the electrical fault of the brushless exciter according to the size of the specific harmonics of the port voltage. The short-circuit fault between the turns of the excitation winding can be judged according to the harmonic characteristics, and the diode open circuit fault and the internal short circuit fault of the armature winding can be distinguished by setting thresholds of different sizes.

[0004] However, since the diode open circuit fault and the armature winding internal short circuit fault have similar harmonic characteristics, the related technical methods cannot clearly distinguish the diode open circuit fault and the armature winding internal short circuit fault through the harmonic characteristics. The fault detection efficiency and reliability are low and need to be solved urgently. Summary of the Invention

[0005] The present invention provides an electrical fault detection method, device and equipment based on a multi-pole detection coil to solve the problem in the related art that it is impossible to clearly distinguish between a diode open circuit fault and an armature winding internal short circuit fault through harmonic characteristics, thereby improving the electrical fault detection effect of a brushless exciter.

[0006] The first aspect of the present invention provides an electrical fault detection method based on a multi-pole detection coil, comprising the following steps: obtaining the pole pair number of a brushless exciter, determining the number of detection coils according to the pole pair number of the brushless exciter, and arranging multiple detection coils on the stator poles of the brushless exciter based on the number of detection coils; calculating the weighting coefficient of each detection coil when the pole pair number of the brushless exciter meets a preset symmetrical distribution condition, and obtaining a composite voltage according to the port voltage of each detection coil based on the weighting coefficient; analyzing the spectral characteristics of the composite voltage to obtain a spectral characteristic analysis result, and obtaining an electrical fault detection result based on the spectral characteristic analysis result.

[0007] Furthermore, in some embodiments, determining the number of detection coils based on the number of pole pairs of the brushless exciter includes: if the number of pole pairs of the brushless exciter is an even number, then the number of detection coils is the sum of the number of pole pairs and a first preset value, wherein the first preset value is an even number; if the number of pole pairs of the brushless exciter is an odd number, then the number of detection coils is the sum of the number of pole pairs and a second preset value, wherein the first preset value is an odd number.

[0008] Furthermore, in some embodiments, when the number of pole pairs of the brushless exciter satisfies a preset symmetrical distribution condition, the weighted coefficient of each detection coil is calculated, including: determining the position of each detection coil; establishing a complex form homogeneous linear equation group according to the number of detection coils and the position of each detection coil, and simplifying the complex form homogeneous linear equation group to obtain a simplified complex form homogeneous linear equation group; converting the simplified complex form homogeneous linear equation group into a real algebraic equation group, and solving the real algebraic equation group through a preset algorithm to obtain the weighted coefficient of each detection coil.

[0009] Furthermore, in some embodiments, the spectrum characteristic analysis results include that the composite voltage contains only integer harmonics that meet the first condition, the composite voltage contains only fractional harmonics determined by the pole pair number, but does not include the fundamental wave and various integer harmonics, and the composite voltage contains only fractional harmonics, but does not include fractional harmonics that meet the second condition, and does not include the fundamental wave and any of the various integer harmonics.

[0010] Further, in some embodiments, the electrical fault detection result obtained based on the spectrum characteristic analysis result includes: if the spectrum characteristic analysis result is that the composite voltage only contains integer harmonics that meet the first condition, then the electrical fault detection result is an inter-turn short circuit fault of the excitation winding; if the spectrum characteristic analysis result is that the composite voltage only contains fractional harmonics determined by the pole pair number, but does not contain the fundamental wave and various integer harmonics, then the electrical fault detection result is a diode open circuit fault; if the spectrum characteristic analysis result is that the composite voltage only contains fractional harmonics, but does not contain fractional harmonics that meet the second condition, and does not contain the fundamental wave and various integer harmonics, then the electrical fault detection result is an internal short circuit fault of the armature winding.

[0011] According to the electrical fault detection method based on multi-pole detection coils provided by an embodiment of the present invention, the number of detection coils is determined and arranged according to the number of pole pairs of the brushless exciter. When the number of pole pairs meets the symmetrical distribution condition, the weighted coefficient of each coil is calculated and the port voltage is synthesized. Finally, the spectrum characteristics of the synthesized voltage are analyzed to obtain the electrical fault detection result. This solves the problem in related technologies that it is impossible to clearly distinguish between diode open circuit faults and armature winding internal short circuit faults through harmonic characteristics, and improves the electrical fault detection effect of the brushless exciter.

[0012] The second aspect of the present invention provides an electrical fault detection device based on a multi-pole detection coil, wherein the device includes: an acquisition module, which acquires the pole pair number of the brushless exciter, and determines the number of detection coils according to the pole pair number of the brushless exciter, and sets multiple detection coils on the stator poles of the brushless exciter based on the number of detection coils; a calculation module, which is used to calculate the weighting coefficient of each detection coil when the pole pair number of the brushless exciter meets the preset symmetrical distribution condition, and obtain a composite voltage according to the weighting coefficient and the port voltage of each detection coil; an analysis module, which is used to analyze the spectral characteristics of the composite voltage to obtain a spectral characteristic analysis result, and obtain an electrical fault detection result according to the spectral characteristic analysis result.

[0013] Furthermore, in some embodiments, the acquisition module is specifically used to: when the number of pole pairs of the brushless exciter is an even number, the number of detection coils is the sum of the number of pole pairs and a first preset value, wherein the first preset value is an even number; when the number of pole pairs of the brushless exciter is an odd number, the number of detection coils is the sum of the number of pole pairs and a second preset value, wherein the first preset value is an odd number.

[0014] Furthermore, in some embodiments, the calculation module is specifically used to: determine the position of each detection coil; establish a complex form homogeneous linear equation group based on the number of detection coils and the position of each detection coil, and simplify the complex form homogeneous linear equation group to obtain a simplified complex form homogeneous linear equation group; convert the simplified complex form homogeneous linear equation group into a real algebraic equation group, and solve the real algebraic equation group through a preset algorithm to obtain the weighting coefficient of each detection coil.

[0015] Furthermore, in some embodiments, the spectrum characteristic analysis results include that the composite voltage contains only integer harmonics that meet the first condition, the composite voltage contains only fractional harmonics determined by the pole pair number, but does not include the fundamental wave and various integer harmonics, and the composite voltage contains only fractional harmonics, but does not include fractional harmonics that meet the second condition, and does not include the fundamental wave and any of the various integer harmonics.

[0016] Further, in some embodiments, the analysis module is specifically used to: if the spectrum characteristic analysis result is that the composite voltage only contains integer harmonics that meet the first condition, then the electrical fault detection result is an inter-turn short circuit fault of the excitation winding; if the spectrum characteristic analysis result is that the composite voltage only contains fractional harmonics determined by the pole pair number, but does not contain the fundamental wave and various integer harmonics, then the electrical fault detection result is a diode open circuit fault; if the spectrum characteristic analysis result is that the composite voltage only contains fractional harmonics, but does not contain fractional harmonics that meet the second condition, and does not contain the fundamental wave and various integer harmonics, then the electrical fault detection result is an internal short circuit fault of the armature winding.

[0017] According to the electrical fault detection device based on multi-pole detection coils provided by an embodiment of the present invention, the number of detection coils is determined and arranged according to the number of pole pairs of the brushless exciter. When the number of pole pairs meets the symmetrical distribution condition, the weighted coefficient of each coil is calculated and the port voltage is synthesized. Finally, the spectrum characteristics of the synthesized voltage are analyzed to obtain the electrical fault detection result. This solves the problem in the related art that it is impossible to clearly distinguish between a diode open circuit fault and an armature winding internal short circuit fault through harmonic characteristics, and improves the electrical fault detection effect of the brushless exciter.

[0018] An embodiment of the third aspect of the present invention provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the electrical fault detection method based on the multi-pole detection coil described in the above embodiment.

[0019] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the electrical fault detection method based on a multi-pole detection coil as described in the above embodiment.

[0020] A fifth aspect of the present invention provides a computer program product, including a computer program, which is executed to implement the electrical fault detection method based on the multi-pole detection coil as described in the above embodiment.

[0021] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0023] Figure 1 A flowchart of an electrical fault detection method based on a multi-pole detection coil according to an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the steady-state voltage and spectrum of the magnetic pole detection coil during normal operation of a powered-on brushless exciter according to a specific embodiment of the present invention;

[0025] Figure 3 A schematic diagram of the steady-state voltage and spectrum of the magnetic pole detection coil in the event of a 5% inter-turn short circuit fault in the excitation winding of a power-on brushless exciter provided in accordance with a specific embodiment of the present invention;

[0026] Figure 4 A schematic diagram of the steady-state voltage and spectrum of the magnetic pole detection coil of a power-on brushless exciter with a single diode open (the common cathode diode connected to the A1 branch is open) provided in accordance with a specific embodiment of the present invention;

[0027] Figure 5 A schematic diagram of the steady-state voltage and spectrum of the magnetic pole detection coil of a brushless exciter A1 branch with a 25% (metallic) inter-turn short circuit fault according to a specific embodiment of the present invention;

[0028] Figure 6 A block diagram of an electrical fault detection device based on a multi-pole detection coil according to an embodiment of the present invention;

[0029] Figure 7 A schematic structural diagram of an electronic device provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0031] The following describes an electrical fault detection method, device, and apparatus based on a multi-pole detection coil according to an embodiment of the present invention with reference to the accompanying drawings. In response to the problem mentioned in the background art that the related art cannot clearly distinguish between a diode open circuit fault and an armature winding internal short circuit fault through harmonic characteristics, the present invention provides an electrical fault detection method based on a multi-pole detection coil. The number of detection coils is determined and arranged according to the number of pole pairs of the brushless exciter. When the number of pole pairs satisfies the symmetrical distribution condition, the weighted coefficients of each coil are calculated and the port voltage is synthesized. Finally, the spectrum characteristics of the synthesized voltage are analyzed to obtain the electrical fault detection result. This solves the problem in the related art that the harmonic characteristics cannot clearly distinguish between a diode open circuit fault and an armature winding internal short circuit fault, and improves the electrical fault detection effect of the brushless exciter.

[0032] Before introducing the embodiment of the present invention, the frequency of the induced electromotive force of the magnetic pole detection coil caused by various components of the armature current and the generated spatial fundamental wave and various harmonic magnetic fields is first described.

[0033] Table 1 is a schematic diagram of the frequency of the induced electromotive force of the magnetic pole detection coil caused by the spatial fundamental wave and various harmonic magnetic fields generated by various components of the armature current (DC component, fundamental wave and various harmonics). As shown in Table 1, if there is only If there is space harmonic, then the armature internal short circuit fault (i.e. the corresponding armature current harmonic number μ =1, 3, 5...) will only cause Time harmonics, and the diode open circuit fault (that is, the corresponding armature current harmonic number is μ =0, 2, 4...) will also cause Time harmonics. Therefore, diode open circuit and armature winding internal short circuit faults can be distinguished based on whether these harmonic voltages are included. At the same time, the spatial harmonic magnetic fields included in the armature reaction magnetic field are mainly determined by the topology of the armature winding and the rectifier it is connected to. Generally, various harmonic magnetic fields will exist. By connecting two adjacent magnetic pole detection coils in series, the influence of the spatial fundamental wave and odd-order harmonic magnetic fields on the detection coil combination can be eliminated, thereby achieving fault differentiation. If the voltages of multiple magnetic pole detection coils are weighted and summed to obtain a "synthetic voltage", the influence of some fractional harmonic magnetic fields on the "synthetic voltage" of the detection coil can also be eliminated. Therefore, the present invention introduces a synthetic voltage and calculates the port voltage of each detection coil through a weighting coefficient to obtain a synthetic voltage; the spectral characteristics of the synthetic voltage are analyzed to obtain the electrical fault detection result. Among them, the armature winding of the exciter shown in Table 1 is full-pitch, so no even-order armature reaction magnetomotive force is generated. In addition, the symbol "[]" represents a rounding mathematical operator.

[0034] Table 1

[0035]

[0036]

[0037] Specifically, Figure 1 The flowchart is a method for detecting electrical faults based on a multi-pole detection coil according to an embodiment of the present invention.

[0038] like Figure 1 As shown, the electrical fault detection method based on the multi-pole detection coil includes the following steps:

[0039] In step S101 , the number of pole pairs of the brushless exciter is obtained, and the number of detection coils is determined according to the number of pole pairs of the brushless exciter, and multiple detection coils are set on the stator poles of the brushless exciter based on the number of detection coils.

[0040] The number of pole pairs of the brushless exciter refers to the number of a pair of opposite poles in the stator magnetic field, and the detection coil refers to a magnetic pole detection coil used to detect electrical faults of the brushless excitation.

[0041] Furthermore, in some embodiments, the number of detection coils is determined based on the number of pole pairs of the brushless exciter, including: if the number of pole pairs of the brushless exciter is an even number, the number of detection coils is the sum of the number of pole pairs and a first preset value, wherein the first preset value is an even number; if the number of pole pairs of the brushless exciter is an odd number, the number of detection coils is the sum of the number of pole pairs and a second preset value, wherein the first preset value is an odd number.

[0042] Specifically, if the pole pair number P of the brushless exciter is an even number, the number of detection coils is the sum of the pole pair number and the first preset value, that is, the number of detection coils is P+2; if the pole pair number P of the brushless exciter is an odd number, the number of detection coils is the sum of the pole pair number and the second preset value, that is, the number of detection coils is P+1.

[0043] For example, if the pole pair number P of the brushless exciter is 8, the number of detection coils is the sum of the pole pair number and the first preset value, that is, the number of detection coils is 8+2=10; if the pole pair number P of the brushless exciter is 9, the number of detection coils is the sum of the pole pair number and the second preset value, that is, the number of detection coils is 9+1=10.

[0044] In step S102 , when the number of pole pairs of the brushless exciter meets a preset symmetrical distribution condition, a weighting coefficient of each detection coil is calculated, and a composite voltage is obtained according to the weighting coefficient and the port voltage of each detection coil.

[0045] Among them, the preset symmetrical distribution condition means that the weighting coefficients of the i-th pole of the brushless exciter and the magnetic pole detection coil symmetrical to the i-th pole are equal, the weighting coefficient is the weight coefficient of each pole of the brushless exciter, and the composite voltage refers to the total voltage value obtained by the voltages of all magnetic pole detection coils according to the weighting coefficient.

[0046] Furthermore, in some embodiments, when the number of pole pairs of the brushless exciter satisfies a preset symmetrical distribution condition, the weighting coefficient of each detection coil is calculated, including: determining the position of each detection coil; establishing a homogeneous linear equation group in complex form based on the number of detection coils and the position of each detection coil, and simplifying the homogeneous linear equation group in complex form to obtain a simplified homogeneous linear equation group in complex form; converting the simplified homogeneous linear equation group in complex form into a real algebraic equation group, and solving the real algebraic equation group through a preset algorithm to obtain the weighting coefficient of each detection coil.

[0047] Specifically, let the voltage at the i-th magnetic pole detection coil port be u i , its weighted coefficient is c i (i=0, 1, 2, ..., 2P-1), where the 0th magnetic pole detection is the symmetrically distributed 2Pth magnetic pole detection. To make the combined voltage of all magnetic pole detection coils generated by the kth harmonic magnetic field 0, the following conditions should be met:

[0048]

[0049] If the rational expression k satisfies the equation (1), then (2l±k) also satisfies the equation (1), where l is an integer. If we can eliminate The influence of harmonic and fundamental magnetic fields on the synthetic voltage of the detection coil is calculated according to formula (1): Harmonics and odd-order harmonic magnetic fields such as the 3rd and 5th times will not cause synthetic voltages, so the following equations can be established:

[0050]

[0051]

[0052] Furthermore, if the number of pole pairs P of the brushless exciter is an even number, then the equation group (2) includes P+1 homogeneous linear algebraic equations. If the weighting coefficient c is P+2 =c O+3 =…=c 2P-1 =0, then the composite voltage u com It can be obtained by weighted summing the voltages of the 0th pole (i.e., the 2P pole), the 1st pole, ..., the Pth pole, and the P+1th pole, a total of (P+2) magnetic pole detection coils:

[0053]

[0054] According to the symmetry condition of formula (1), The weighting coefficients of each pole should satisfy:

[0055]

[0056] Then the complex form of the homogeneous linear equations is:

[0057]

[0058] Let c P+1-i =c i (i=0,1,…P / 2), the complex form homogeneous linear equations can be simplified to the simplified complex form homogeneous linear equations:

[0059]

[0060] Furthermore, formula (6) is converted into a set of real algebraic equations:

[0061]

[0062] As a possible implementation method, when the number of pole pairs P of the brushless exciter is an even number 8, the algebraic equation group corresponding to formula (6) is:

[0063]

[0064] Among them, formula (7) is a rank Homogeneous linear algebraic equations, that is, when k = 1, formula (7) is an identity, where common There are two unrelated algebraic equations, but the unknowns in formula (7) are Therefore, formula (7) has an infinite number of solutions, and the solutions are proportional to each other. The unknowns, that is, the weighting coefficients of the detection coils at each pole, can be normalized. For example, the weighting coefficient of the 0th pole (2P) is set to c0 = 1.0, and the Gaussian elimination method is used to solve the formula:

[0065]

[0066] The weighting coefficient c of other magnetic poles can be obtained i (=c P+1-i ),i=1,2,…P / 2.

[0067] Furthermore, if the number of pole pairs P of the brushless exciter is an odd number, then the equation group (2) includes P homogeneous linear algebraic equations. If c P+1 =c P+2 =c P+3 =…=c 2P-1 =0, then the composite voltage u com It can be obtained by weighted summing the voltages of the 0th pole (i.e., the 2P pole), the 1st pole, ..., the Pth pole, a total of (P+1) magnetic pole detection coils:

[0068]

[0069] According to the symmetry condition of formula (1), The weighting coefficients of each pole should satisfy:

[0070]

[0071] Then the complex form of the homogeneous linear equations is:

[0072]

[0073] Let c P-i =c i (for i=0,1,… ), the complex form homogeneous linear equations can be simplified to the simplified complex form homogeneous linear equations:

[0074]

[0075] Furthermore, formula (12) is transformed into a set of real algebraic equations:

[0076]

[0077] Among them, formula (13) is a rank The homogeneous linear algebraic equations of , that is, when k = 1, formula (13) is an identity, common There are two unrelated algebraic equations, but the unknowns in formula (13) are Therefore, formula (13) has an infinite number of solutions, and the solutions are proportional to each other. The unknown number, that is, the weighting coefficient of each pole detection coil can be normalized. For example, the weighting coefficient of the 0th pole (2P) is set to c0 = 1.0, and the Gaussian elimination method is used to solve the formula:

[0078]

[0079] The weighting coefficient c of other magnetic poles can be obtained i (=c P-i ),i=1,2,…

[0080] Furthermore, when the number of pole pairs P of the brushless exciter is an even number, the synthetic voltage u com It can be obtained by weighted summing the voltages of the 0th pole (i.e., the 2P pole), the 1st pole, ..., the Pth pole, the P+1th pole, and a total of (P+2) magnetic pole detection coils:

[0081]

[0082] At the same time, when the number of pole pairs P of the brushless exciter is an odd number, the synthetic voltage u comIt can be obtained by weighted summing the voltages of the 0th pole (i.e., the 2P pole), the 1st pole, ..., the Pth pole, and the Pth pole, a total of (P+1) magnetic pole detection coils:

[0083]

[0084] Thus, the weighting coefficient of each detection coil is calculated, and the combined voltage is obtained according to the port voltage of each detection coil based on the weighting coefficient.

[0085] In step S103 , the spectrum characteristics of the composite voltage are analyzed to obtain a spectrum characteristics analysis result, and an electrical fault detection result is obtained based on the spectrum characteristics analysis result.

[0086] The frequency spectrum characteristic refers to the frequency domain distribution of the synthesized voltage after weighted summation of the voltages of multiple magnetic pole detection coils, including different time harmonics.

[0087] Further, in some embodiments, the spectrum characteristic analysis results include that the composite voltage contains only integer harmonics that meet the first condition, the composite voltage contains only fractional harmonics determined by the pole pair number, but does not include the fundamental wave and various integer harmonics, and the composite voltage contains only fractional harmonics, but does not include fractional harmonics that meet the second condition, and does not include the fundamental wave and any of the various integer harmonics.

[0088] The first condition refers to the occurrence of specific integer harmonics of the rated frequency, and the second condition refers to certain specific fractional harmonics.

[0089] Furthermore, in some embodiments, an electrical fault detection result is obtained based on the spectrum characteristic analysis result, including: if the spectrum characteristic analysis result is that the composite voltage only contains integer harmonics that meet the first condition, then the electrical fault detection result is an inter-turn short circuit fault of the excitation winding; if the spectrum characteristic analysis result is that the composite voltage only contains fractional harmonics determined by the pole pair number, but does not contain the fundamental wave and various integer harmonics, then the electrical fault detection result is a diode open circuit fault; if the spectrum characteristic analysis result is that the composite voltage only contains fractional harmonics, but does not contain fractional harmonics that meet the second condition, and does not contain the fundamental wave and various integer harmonics, then the electrical fault detection result is an internal short circuit fault of the armature winding.

[0090] Specifically, if specific integer harmonics appear in the composite voltage, such as 6 times or 12 times the rated frequency, the electrical fault detection result is an inter-turn short circuit fault in the excitation winding; if only fractional harmonics related to the pole pair number P appear in the composite voltage, such as "1 / P" times or "2 / P" times of the rated frequency, but there is no fundamental wave and integer harmonics, the electrical fault detection result is a diode open circuit fault; if the composite voltage only contains fractional harmonics, but does not contain specific harmonics (such as 1 / 8, 2 / 8, 3 / 8 harmonics), and does not contain the fundamental wave and various integer harmonics, the electrical fault detection result is an internal short circuit fault in the armature winding.

[0091] In order to enable those skilled in the art to better understand the electrical fault detection method based on the multi-pole detection coil according to the embodiment of the present invention, a detailed description will be given below in conjunction with specific embodiments.

[0092] For example, a three-phase brushless exciter has a capacity of 5800kW, a stator with 16 magnetic poles (pole pairs P = 8), and a rotor armature with 16 parallel branches per phase. The number of pole pairs is an even number. The weighted sum of the pole detection coils of pole 0 (i.e., pole 16) and poles 1 to 9 can be used to obtain the composite voltage of the pole detection coil group:

[0093]

[0094] where u i is the terminal voltage of the i-th magnetic pole detection coil, c i is the weighted coefficient of the voltage at the port of the i-th magnetic pole detection coil. Substituting it into formula (8), we can obtain the linear equation group as follows:

[0095]

[0096]

[0097]

[0098]

[0099] The Gaussian elimination method is used to solve the equations and obtain the weighting coefficients of the 1st to 4th pole detection coil voltages:

[0100] c1(=c8)=5.027339

[0101] c2(=c7)=13.137071

[0102] c3(=c6)=23.191750

[0103] c4(=c5)=30.301482

[0104] Furthermore, based on the two-dimensional magnetic field finite element-circuit coupling model of the powered brushless exciter established in the AnsysEM software environment, the voltage at the port of each magnetic pole detection coil and the steady-state waveform of the synthetic voltage and its spectrum diagram under normal operation, single diode open circuit (open cathode diode connected to A1 branch), 25% (metallic) inter-turn short circuit of A1 branch and 5% (metallic) inter-turn short circuit of excitation winding can be calculated. Among them, the exciter speed n is set to the rated speed n N , that is, n=n N =1500r / min, then the fundamental frequency of the armature winding current is

[0105] Figure 2 This is a schematic diagram of the steady-state voltage and spectrum of the magnetic pole detection coil during normal operation of a powered-on brushless exciter according to a specific embodiment of the present invention. Figure 3 This is a schematic diagram of the steady-state voltage and spectrum of the magnetic pole detection coil in the event of a 5% inter-turn short circuit fault in the excitation winding of a power-on brushless exciter provided by a specific embodiment of the present invention. Figure 4 Schematic diagram of the steady-state voltage and spectrum of the magnetic pole detection coil of a brushless exciter with a single diode open circuit (the common cathode diode connected to the A1 branch is open circuit) provided by a specific embodiment of the present invention. Figure 5 A schematic diagram of the steady-state voltage and spectrum of the magnetic pole detection coil of a brushless exciter A1 branch with a 25% (metallic) inter-turn short circuit fault provided according to a specific embodiment of the present invention.

[0106] in, Figure 2 (a) is the steady-state waveform of the voltage u0 at the 0th pole (i.e., the 16th pole) detection coil port. Figure 2 (b) The steady-state spectrum of the voltage u0 at the 0th pole (i.e., the 16th pole) detection coil port. Figure 2 (c) is the steady-state waveform of the voltage u9 at the 9th pole detection coil port. Figure 2 (d) is the steady-state spectrum of the voltage u9 at the 9th pole detection coil port. Figure 2 (e) is the steady-state waveform of u0+u9, Figure 2 (f) is the steady-state spectrum of u0+u9;

[0107] Figure 3 (a) is the steady-state waveform of the voltage u0 at the 0th pole (i.e., the 16th pole) detection coil port. Figure 3 (b) is the steady-state spectrum of the voltage u0 at the 0th pole (i.e., the 16th pole) detection coil port. Figure 3 (c) is the steady-state waveform of the 9th pole detection coil terminal voltage u9. Figure 3 (d) is the steady-state spectrum of the voltage u9 at the 9th pole detection coil port. Figure 3 (e) is the steady-state waveform of u0+u9, Figure 3(f) is the steady-state spectrum of u0+u9;

[0108] Figure 4 (a) is the steady-state waveform of the voltage u0 at the 0th pole (i.e., the 16th pole) detection coil port. Figure 4 (b) is the steady-state spectrum of the voltage u0 at the 0th pole (i.e., the 16th pole) detection coil port. Figure 4 (c) is the steady-state waveform of the 9th pole detection coil terminal voltage u9. Figure 4 (d) is the steady-state spectrum of the voltage u9 at the 9th pole detection coil port. Figure 4 (e) is the steady-state waveform of u0+u9, Figure 4 Where (f) is the steady-state spectrum of u0+u9, Figure 4 (g) is the composite voltage u of 10 magnetic poles com Steady-state waveform, Figure 4 (h) is the composite voltage u of 10 magnetic poles com The steady-state spectrum of

[0109] Figure 5 (a) is the steady-state waveform of the voltage u0 at the 0th pole (i.e., the 16th pole) detection coil port. Figure 5 (b) is the steady-state spectrum of the voltage u0 at the 0th pole (i.e., the 16th pole) detection coil port. Figure 5 (c) is the steady-state waveform of the 9th pole detection coil terminal voltage u9. Figure 5 (d) is the steady-state spectrum of the voltage u9 at the 9th pole detection coil port. Figure 5 (e) is the steady-state waveform of u0+u9, Figure 5 Where (f) is the steady-state spectrum of u0+u9, Figure 5 (g) is the composite voltage u of 10 magnetic poles com Steady-state waveform, Figure 5 (h) is the composite voltage u of 10 magnetic poles com The steady-state spectrum.

[0110] like Figure 2 As shown in (e) and (f), the normal operation of the brushless exciter, the terminal voltage u of each two pole detection coils in series is i +u 9-i (i=0,1,2,… )The simulation results are all 0, so the composite voltage of the 10 magnetic pole detection coils is also 0.

[0111] Further, if Figure 3 、 Figure 4 and Figure 5 As shown in the figure, after the excitation winding inter-turn short circuit, diode open circuit and armature winding inter-turn short circuit fault, the terminal voltage u of the two pole detection coils in series is i +u 9-i(i=0,1,2,… ) The simulation results are no longer 0 and are significantly greater than the normal working condition, which can be used to determine the occurrence of a fault. By comparing the sum of the two detection coil voltages after the fault, u i +u 9-i (i=0,1,2,… ) spectrum, where Figure 3 It can be seen that when the composite voltage only includes the 6th, 12th (6kth) harmonics, but does not include fractional harmonics and fundamental, 2nd and other harmonics, it can be determined as an inter-turn short circuit fault in the excitation winding; Figure 4 and Figure 5 It can be seen that the port voltage of each magnetic pole detection coil contains various fractional harmonics, and the port voltage u of each two magnetic pole detection coils in series is i +u 9-i They also contain various fractional harmonics, and the composite voltage u obtained by weighted summation of the voltages at the ports of the 10 magnetic pole detection coils is com It presents different spectrum characteristics: the diode open circuit fault causes the magnetic pole detection coil synthetic voltage u com 1 / 8 times, 2 / 8 times, 3 / 8 times, 5 / 8 times, 6 / 8 times, etc. (and Harmonics, while the internal short circuit fault of the armature winding will not cause u com The 1 / 8, 2 / 8, and 3 / 8 harmonics are not included, but there are 5 / 8, 6 / 8, and 7 / 8 harmonics. This can be used to distinguish between the open diode fault and the internal short circuit fault of the armature winding of the brushless exciter. For example, Figure 5 It can be seen that when the composite voltage contains fractional harmonics (but not the fundamental wave and various integer harmonics), but does not include 1 / 8, 2 / 8, and 3 / 8 harmonics, it can be determined as an internal short circuit fault in the armature winding.

[0112] According to the electrical fault detection method based on multi-pole detection coils provided by an embodiment of the present invention, the number of detection coils is determined and arranged according to the number of pole pairs of the brushless exciter. When the number of pole pairs meets the symmetrical distribution condition, the weighted coefficient of each coil is calculated and the port voltage is synthesized. Finally, the spectrum characteristics of the synthesized voltage are analyzed to obtain the electrical fault detection result. This solves the problem in related technologies that it is impossible to clearly distinguish between diode open circuit faults and armature winding internal short circuit faults through harmonic characteristics, and improves the electrical fault detection effect of the brushless exciter.

[0113] Next, an electrical fault detection device based on a multi-pole detection coil according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0114] Figure 6 It is a block diagram of an electrical fault detection device based on a multi-pole detection coil according to an embodiment of the present invention.

[0115] like Figure 6 As shown, the electrical fault detection device 10 based on the multi-pole detection coil includes: an acquisition module 100 , a calculation module 200 and an analysis module 300 .

[0116] Among them, the acquisition module 100 is used to obtain the pole pair number of the brushless exciter, determine the number of detection coils according to the pole pair number of the brushless exciter, and set multiple detection coils on the stator poles of the brushless exciter based on the number of detection coils; the calculation module 200 is used to calculate the weighting coefficient of each detection coil when the pole pair number of the brushless exciter meets the preset symmetrical distribution condition, and obtain the synthetic voltage according to the weighting coefficient and the port voltage of each detection coil; the analysis module 300 is used to analyze the spectral characteristics of the synthetic voltage, obtain the spectral characteristic analysis results, and obtain the electrical fault detection results according to the spectral characteristic analysis results.

[0117] Furthermore, in some embodiments, the acquisition module 100 is specifically used to: when the number of pole pairs of the brushless exciter is an even number, the number of detection coils is the sum of the number of pole pairs and a first preset value, wherein the first preset value is an even number; when the number of pole pairs of the brushless exciter is an odd number, the number of detection coils is the sum of the number of pole pairs and a second preset value, wherein the first preset value is an odd number.

[0118] Furthermore, in some embodiments, the calculation module 200 is specifically used to: determine the position of each detection coil; establish a complex form homogeneous linear equation system according to the number of detection coils and the position of each detection coil, and simplify the complex form homogeneous linear equation system to obtain a simplified complex form homogeneous linear equation system; convert the simplified complex form homogeneous linear equation system into a real algebraic equation system, and solve the real algebraic equation system through a preset algorithm to obtain a weighted coefficient for each detection coil

[0119] Further, in some embodiments, the spectrum characteristic analysis results only include the composite voltage containing integer harmonics that meet the first condition, the composite voltage containing only fractional harmonics determined by the pole pair number, but not the fundamental wave and various integer harmonics, the composite voltage containing only fractional harmonics, but not fractional harmonics that meet the second condition, and not the fundamental wave and any of the various integer harmonics.

[0120] Furthermore, in some embodiments, the analysis module 300 is specifically used to: if the spectrum characteristic analysis result is that the composite voltage only contains integer harmonics that meet the first condition, then the electrical fault detection result is an inter-turn short circuit fault of the excitation winding; if the spectrum characteristic analysis result is that the composite voltage only contains fractional harmonics determined by the pole pair number, but does not contain the fundamental wave and various integer harmonics, then the electrical fault detection result is a diode open circuit fault; if the spectrum characteristic analysis result is that the composite voltage only contains fractional harmonics, but does not contain fractional harmonics that meet the second condition, and does not contain the fundamental wave and various integer harmonics, then the electrical fault detection result is an internal short circuit fault of the armature winding.

[0121] According to the electrical fault detection device based on multi-pole detection coils provided by an embodiment of the present invention, the number of detection coils is determined and arranged according to the number of pole pairs of the brushless exciter. When the number of pole pairs meets the symmetrical distribution condition, the weighted coefficient of each coil is calculated and the port voltage is synthesized. Finally, the spectrum characteristics of the synthesized voltage are analyzed to obtain the electrical fault detection result. This solves the problem in the related art that it is impossible to clearly distinguish between a diode open circuit fault and an armature winding internal short circuit fault through harmonic characteristics, and improves the electrical fault detection effect of the brushless exciter.

[0122] Figure 7 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present invention. The electronic device may include:

[0123] Memory 701 , processor 702 , and computer programs stored in the memory 701 and executable on the processor 702 .

[0124] When the processor 702 executes the program, the electrical fault detection method based on the multi-pole detection coil provided in the above embodiment is implemented.

[0125] Furthermore, the electronic device further includes:

[0126] The communication interface 703 is used for communication between the memory 701 and the processor 702 .

[0127] The memory 701 is used to store computer programs that can be run on the processor 702 .

[0128] The memory 701 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0129] If the memory 701, processor 702, and communication interface 703 are implemented independently, the communication interface 703, memory 701, and processor 702 can be interconnected via a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be divided into address buses, data buses, control buses, etc. For ease of representation, Figure 7 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0130] Optionally, in a specific implementation, if the memory 701, the processor 702 and the communication interface 703 are integrated on a chip, the memory 701, the processor 702 and the communication interface 703 can communicate with each other through an internal interface.

[0131] The processor 702 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention.

[0132] In addition, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the above-mentioned electrical fault detection method based on the multi-pole detection coil is implemented.

[0133] In addition, an embodiment of the present invention further provides a computer program product, including a computer program, which is executed to implement the above-mentioned electrical fault detection method based on multi-pole detection coils.

[0134] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0135] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "N" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0136] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing a custom logical function or step of a process, and the scope of the preferred embodiments of the invention includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of the invention pertain.

[0137] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having logic gate circuits for implementing logic functions on data signals, an application-specific integrated circuit having suitable combinational logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0138] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

Claims

1. An electrical fault detection method based on a multi-pole detection coil, characterized in that: The following steps are involved: Obtaining the number of pole pairs of a brushless exciter, determining the number of detection coils according to the number of pole pairs of the brushless exciter, and providing a plurality of detection coils on the stator poles of the brushless exciter based on the number of detection coils; When the number of pole pairs of the brushless exciter satisfies a preset symmetrical distribution condition, a weighting coefficient of each detection coil is calculated, and a synthetic voltage is obtained according to the port voltage of each detection coil based on the weighting coefficient; The frequency spectrum characteristics of the synthesized voltage are analyzed to obtain a frequency spectrum characteristics analysis result, and an electrical fault detection result is obtained based on the frequency spectrum characteristics analysis result.

2. The method according to claim 1, characterized in that Determining the number of detection coils according to the number of pole pairs of the brushless exciter includes: If the number of pole pairs of the brushless exciter is an even number, the number of detection coils is the sum of the number of pole pairs and a first preset value, wherein the first preset value is an even number; If the number of pole pairs of the brushless exciter is an odd number, the number of detection coils is the sum of the number of pole pairs and a second preset value, wherein the first preset value is an odd number.

3. The method according to claim 1, characterized in that When the number of pole pairs of the brushless exciter satisfies a preset symmetrical distribution condition, calculating the weighting coefficient of each detection coil includes: determining a position of each detection coil; Establishing a complex form homogeneous linear equation system according to the number of detection coils and the position of each detection coil, and simplifying the complex form homogeneous linear equation system to obtain a simplified complex form homogeneous linear equation system; The simplified complex form homogeneous linear equation group is converted into a real algebraic equation group, and the real algebraic equation group is solved by a preset algorithm to obtain the weighting coefficient of each detection coil.

4. The method according to claim 1, wherein The spectrum characteristic analysis results include: the composite voltage contains only integer harmonics that meet the first condition, the composite voltage contains only fractional harmonics determined by the pole pair number, but does not include the fundamental wave and various integer harmonics, and the composite voltage contains only fractional harmonics, but does not include fractional harmonics that meet the second condition, and does not include the fundamental wave and any of the various integer harmonics.

5. The method according to claim 4, characterized in that Obtaining an electrical fault detection result based on the spectrum characteristic analysis result includes: If the spectrum characteristic analysis result shows that the composite voltage only contains integer harmonics that meet the first condition, then the electrical fault detection result is an inter-turn short circuit fault of the excitation winding; If the spectrum characteristic analysis result shows that the composite voltage only contains fractional harmonics determined by the pole pair number but does not contain the fundamental wave and various integer harmonics, then the electrical fault detection result is a diode open circuit fault; If the spectrum characteristic analysis result shows that the composite voltage only includes fractional harmonics but does not include fractional harmonics that meet the second condition and does not include the fundamental wave and various integer harmonics, then the electrical fault detection result is an internal short circuit fault of the armature winding.

6. An electrical fault detection device based on a multi-pole detection coil, characterized in that: The device comprises: an acquisition module, which acquires the number of pole pairs of the brushless exciter, determines the number of detection coils according to the number of pole pairs of the brushless exciter, and sets a plurality of detection coils on the stator poles of the brushless exciter based on the number of detection coils; a calculation module, configured to calculate a weighting coefficient of each detection coil when the number of pole pairs of the brushless exciter satisfies a preset symmetrical distribution condition, and obtain a synthetic voltage according to the port voltage of each detection coil based on the weighting coefficient; The analysis module is used to analyze the spectrum characteristics of the synthetic voltage to obtain a spectrum characteristic analysis result, and obtain an electrical fault detection result based on the spectrum characteristic analysis result.

7. The device according to claim 6, characterized in that: The acquisition module is specifically used to: When the number of pole pairs of the brushless exciter is an even number, the number of the detection coils is the sum of the number of pole pairs and a first preset value, wherein the first preset value is an even number; When the number of pole pairs of the brushless exciter is an odd number, the number of the detection coils is the sum of the number of pole pairs and a second preset value, wherein the first preset value is an odd number.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the electrical fault detection method based on the multi-pole detection coil according to any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the electrical fault detection method based on a multi-pole detection coil as described in any one of claims 1 to 5.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the electrical fault detection method based on a multi-pole detection coil according to any one of claims 1 to 5 is implemented.

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