Claw-pole generator rectifier circuit fault diagnosis method, system, equipment and medium

Abstract

The present invention discloses a claw-pole generator rectifier circuit fault diagnosis method, system, equipment and medium, the method includes the following steps: S1, according to the mechanical parameters and operating speed of the claw-pole generator to be tested, using analytical method to obtain the theoretical electromagnetic force space order and frequency information of the claw-pole generator to be tested; S2, collecting the noise time domain signal dissipated into the air sound field of the claw-pole generator to be tested; S3, obtaining the noise frequency spectrum of the motor to be tested; S4, for the noise spectrum obtained in step S3, identifying the harmonic frequency with the largest noise amplitude, and comparing it with the result of analytical calculation in S1, according to whether the frequencies of the peak noise harmonics of the two are the same, judging whether a single-tube open circuit fault or a short circuit fault occurs. Based on the output DC current and the motor noise time domain signal, the present invention can quickly diagnose the single-tube open circuit and short circuit of the vehicle-mounted claw-pole motor rectifier diode without disassembling the motor.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic circuit fault diagnosis, and in particular relates to a claw-pole generator rectifier circuit fault diagnosis method, system, equipment and medium. Background Art

[0002] Claw pole generator is a type of synchronous motor. Due to its simple structure, low manufacturing cost, wide operating speed range and high reliability, almost all fuel-powered cars currently use claw pole generators as on-board generators. In order to ensure power output density, claw pole generators are often designed to work under high electromagnetic loads. The single diode on its built-in rectifier bridge is prone to open circuit or short circuit under high temperature and long-term pressure. This will cause the motor's power generation quality to deteriorate and even increase the possibility of motor resonance. Therefore, it is necessary to diagnose and eliminate circuit faults in a timely manner.

[0003] A diode failure will change the amplitude and phase of the phase current. The phase current directly acts on the stator armature, causing changes in the air gap magnetic field, thereby changing the electromagnetic force of the claw pole generator, and ultimately affecting the electromagnetic vibration and noise of the motor.

[0004] At present, there are few documents or patents specifically related to the fault diagnosis of vehicle-mounted motor diode rectifier circuits. For the fault diagnosis of three-phase full-bridge rectifier circuits, direct measurement method or "modeling-lookup table" method is usually used. The former directly measures the output characteristics of the internal rectifier devices of the generator by disassembling the generator set. For example, patent CN103744013A proposes a full-bridge circuit diagnosis method that verifies the integrity of each thyristor half-bridge pair by injecting complementary PWM signals. However, this method requires disassembly of equipment during actual maintenance, which is time-consuming. The latter selects a set of circuit characteristic parameters, encodes the normal working state and fault state of the circuit in turn, and finally manually constructs a fault lookup table or uses a neural network to establish a fault prediction model. For example, patent CN103018601B performs wavelet packet decomposition and coefficient reconstruction on the output DC voltage signal, obtains its power spectrum and characteristic frequency, and forms a comparison table of polythyristor open-circuit faults in the rectifier circuit of the wind power system. However, the above-mentioned "lookup table-modeling" method often only focuses on the situation of open circuit of switching devices, and rarely considers the diagnosis of short circuit of switching devices. Moreover, if a neural network is used to build a prediction model, if the characteristic parameters and optimization methods are not selected properly, it often causes the network to fall into local minimum points during training. Moreover, these problems cannot be adjusted quickly due to the complexity of the grid and the ambiguity to programmers, which in turn affects the accuracy of the model judgment. Summary of the invention

[0005] The main purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a claw-pole generator rectifier circuit fault diagnosis method, system, equipment and medium. The present invention can quickly diagnose the open circuit and short circuit of a single-tube claw-pole generator rectifier diode on a vehicle without disassembling the motor.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] On one hand, the present invention provides a method for diagnosing a fault in a rectifier circuit of a claw-pole generator, comprising the following steps:

[0008] S1. According to the mechanical parameters and operating speed of the claw-pole generator to be tested, the theoretical electromagnetic force spatial order and frequency information of the claw-pole generator to be tested are obtained by using an analytical method;

[0009] S2, collecting the noise time domain signal dissipated from the claw-pole generator to be tested into the air sound field;

[0010] S3, performing one-dimensional fast Fourier transform processing on the collected noise time domain signal to obtain the noise frequency spectrum of the motor to be tested;

[0011] S4, for the noise spectrum obtained in step S3, identify the harmonic frequency with the largest noise amplitude, and compare it with the result of analytical calculation in S1. If the frequencies of the peak noise harmonics of the two are different, it is considered that a single-tube fault has occurred, and continue to perform steps S5-S7. Otherwise, it is considered that no single-tube fault has occurred in the rectifier circuit of the claw-pole generator to be tested;

[0012] S5. Get the rated output current I of the claw-pole generator d0 , and detect the output current I at the DC output end of the claw-pole generator rectifier circuit d ;

[0013] S6, if I d Compared with the rated output current I d0 If the weakening range is within 10%, it is considered that a single-tube open-circuit fault has occurred;

[0014] S7, if I d Compared with the rated output current I d0 If the weakening exceeds 10%, it is considered that a single-tube short-circuit fault has occurred.

[0015] As a preferred technical solution, in step S1, the analytical method performs Fourier decomposition on the stator and rotor magnetic potentials of the claw-pole generator when loaded and considers the slotting effect of the stator and rotor, and then uses Ohm's law under magnetic field conditions to obtain the synthetic magnetic field of the air gap; finally, the electromagnetic force is calculated according to the Maxwell stress tensor equation, and its frequency information is read after ignoring its time-invariant components and minor time-varying components.

[0016] As a preferred technical solution, the analytical method is specifically:

[0017] S11. Calculate the radial air gap composite magnetic field B of the claw-pole generator without considering magnetic leakage and magnetic saturation r (θ,t,z),B r (θ,t,z)=B a (θ,t,z)+B f (θ,t,z);

[0018] Among them, B a (θ, t, z) is the stator armature reaction magnetic field, B f (θ, t, z) is the rotor excitation magnetic field;

[0019] S12. Use Maxwell tensor method to calculate radial electromagnetic force P r ,have Where, μ0 is the magnetic permeability of air;

[0020] S13. Calculate the spatial order and frequency information of the main vibration wave.

[0021] As a preferred technical solution, in step S11, since the rectifier circuit fault has no direct effect on the rotor excitation magnetic field, only the stator armature reaction magnetic field B a (θ, t, z) has an impact on the rectifier circuit fault, B a The calculation formula of (θ, t, z) is as follows:

[0022]

[0023] Among them, B a (θ, t, z) and the air gap composite permeance ∧(θ, t, z) are functions of time t, motor circumferential position θ and axial position z, m is the number of phases, N is the number of winding turns in each stator slot, I m is the armature phase current amplitude, is the initial current phase angle, ω e = pf r is the fundamental frequency electrical angular velocity of the current, ν is the harmonic order of the stator armature magnetomotive force, i is the harmonic order of the stator current, p is the number of pole pairs, f r is the motor speed.

[0024] As a preferred technical solution, in step S13, the electromagnetic force harmonics with a spatial order of 0 constitute the main vibration factor. Therefore, the spatial order is set to 0, the constraint conditions are obtained, the frequency expression is solved, and the 0th order electromagnetic force with a non-zero and lowest frequency is taken as the main vibration electromagnetic force wave;

[0025] Read the motor nameplate or the motor parameter description table issued by the motor manufacturer to obtain the phase number m, winding turns N, armature current amplitude Im, and pole pair number p of the claw-pole generator. Read the car speed instrument panel to obtain the current motor speed fr. Based on the above mechanical parameters and motor speed, the spatial order and frequency information of the main radial electromagnetic force of the claw-pole generator can be obtained.

[0026] As a preferred technical solution, step S2 is specifically as follows:

[0027] S21. Fix the sound level meter 5-10 cm near the claw-pole generator to be tested;

[0028] S22. Remove the protective cover from the head of the sound level meter preamplifier and assemble the microphone to the end of the preamplifier;

[0029] S23. Install batteries in the sound level meter, flip the switch to verify whether an undervoltage alarm occurs. If so, replace the batteries.

[0030] S24. Select frequency weighting A for the sound level meter and set the noise measurement range to 0-100 dB;

[0031] S25. Measure the ambient background noise and read the average ambient background sound pressure level L p0 ;

[0032] S26, control the mechanical speed of the claw-pole generator to be tested to ω e , the excitation current is I f , read the average sound pressure level L under this condition pl , need to ensure e and I f Same as when S1 theory was derived;

[0033] S27. Compare the average sound pressure values ​​obtained from S25 and S26:

[0034] If L pl -L p0 ≥3dB, then proceed to the next step;

[0035] If L pl -L p0 <3dB, the measurement result is invalid, and measures should be taken to reduce the background noise, and then repeat steps S25-S27;

[0036] S28, turning on the sound level meter to maintain the measurement mode, and recording the continuous time signal of the claw pole generator under specific working conditions;

[0037] S29. Depending on the model of the sound level meter, use the USB serial port or RS232 serial port to connect the sound level meter to the computer;

[0038] S210. Set the appropriate sampling frequency for the data receiving software provided by each sound level meter manufacturer. The sampling frequency should be no less than twice the bandwidth. Click "Transfer";

[0039] S211. Export the discrete time data received by the data receiving software into an Excel table.

[0040] As a preferred technical solution, step S3 is specifically as follows:

[0041] S31. Define the sampling frequency F in Matlab s , signal length L, and obtain sampling period T = 1 / F s ;

[0042] S32, using the csvread instruction to import the data in the Excel table obtained in step S211 as the input signal vector S of the FFT instruction;

[0043] S33, use the fft(S) instruction to perform FFT transformation on the collected discrete time domain signal S, and obtain the transformed vector Y;

[0044] S34, define the noise harmonic frequency domain f=Fs*(0:(L / 2)) / L, the noise harmonic single-side amplitude frequency is P=abs(Y / L)*(1:L / 2+1);

[0045] S35. Use plot(f,P) to draw the noise spectrum with the noise harmonic frequency domain f as the horizontal coordinate and the harmonic single-side amplitude frequency P as the vertical coordinate.

[0046] Another aspect of the present invention provides a claw-pole generator rectifier circuit fault diagnosis system, comprising a first acquisition module, a second acquisition module, a third acquisition module and a comparison module;

[0047] The first acquisition module is used to obtain the theoretical electromagnetic force spatial order and frequency information of the claw-pole generator to be tested by using an analytical method according to the mechanical parameters and operating speed of the claw-pole generator to be tested;

[0048] The second acquisition module is used to collect the noise time domain signal dissipated from the claw-pole generator to be tested into the air sound field;

[0049] The third acquisition module is used to perform one-dimensional fast Fourier transform processing on the collected noise time domain signal to obtain the noise frequency spectrum of the motor to be tested;

[0050] The comparison module is used to identify the harmonic frequency with the largest noise amplitude from the noise spectrum obtained by the third acquisition module, and compare it with the result of analytical calculation by the first acquisition module. If the frequencies of the two peak noise harmonics are the same, it is considered that no single-tube fault occurs in the rectifier circuit of the claw-pole generator to be tested; if the frequencies of the two peak noise harmonics are different, it is considered that a single-tube fault occurs, and the following operations are continued:

[0051] Get the rated output current I of the claw-pole generator d0 , and detect the output current I at the DC output end of the claw-pole generator rectifier circuit d ;

[0052] If I d Compared with the rated output current I d0 If the weakening range is within 10%, it is considered that a single-tube open-circuit fault has occurred;

[0053] If I d Compared with the rated output current I d0 If the weakening exceeds 10%, it is considered that a single-tube short-circuit fault has occurred.

[0054] Another aspect of the present invention provides an electronic device, the electronic device comprising:

[0055] at least one processor; and,

[0056] a memory communicatively connected to the at least one processor; wherein,

[0057] The memory stores computer program instructions that can be executed by the at least one processor, and the computer program instructions are executed by the at least one processor so that the at least one processor can perform the claw-pole generator rectifier circuit fault diagnosis method.

[0058] In another aspect, the present invention provides a computer-readable storage medium storing a program, wherein when the program is executed by a processor, the claw-pole generator rectifier circuit fault diagnosis method is implemented.

[0059] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0060] The present invention directly measures and analyzes the noise field and the output current DC signal, thereby achieving the purpose of quickly and conveniently performing qualitative diagnosis on common single-tube faults including short circuits in the rectifier circuit of a multi-phase claw-pole motor with any pole-slot combination, thereby avoiding the detection process of disassembling the claw-pole motor from the entire vehicle or disassembling the motor body structure, and reducing time costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0062] Figure 1 (a)- Figure 1 (c) is a three-phase full-bridge rectifier circuit of a claw-pole generator according to an embodiment of the present invention and an equivalent circuit diagram when a single-tube fault occurs;

[0063] Figure 2 is a flow chart of a method for diagnosing a fault in a rectifier circuit of a claw-pole generator according to an embodiment of the present invention;

[0064] Figure 3 is a comparison diagram of the electromagnetic noise spectrum before and after a diode failure occurs in an embodiment of the present invention;

[0065] Figure 4 (a)- Figure 4 (c) is a comparison diagram of the output current before and after a diode failure occurs in an embodiment of the present invention;

[0066] Figure 5 It is a block diagram of a fault diagnosis system for a claw-pole generator rectifier circuit according to an embodiment of the present invention;

[0067] Figure 6 It is a schematic diagram of the structure of a computer-readable storage medium according to an embodiment of the present invention. DETAILED DESCRIPTION

[0068] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0069] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0070] Based on the output direct current and motor noise time domain signals, the present invention can quickly diagnose the open circuit and short circuit conditions of a single-tube rectifier diode of a vehicle-mounted claw-pole generator without disassembling the motor.

[0071] This embodiment uses a three-phase full-bridge rectifier circuit of a claw-pole generator with p=6 and S=36 slots as a prototype (m=3) to carry out the implementation test of the present invention. Figure 1 (a)- Figure 1 (c) The circuit is integrated between the rear cover and the rear cover inside the motor, as shown in Figure 1 As shown in (a), it consists of three half bridges formed by six diodes (D1-D6) paired in pairs. Figure 4 (a) is the output current spectrum of the claw-pole generator when it is working normally, where the mechanical speed f r is 6000rpm, excitation current I f It is 3A.

[0072] like Figure 2 As shown, a claw-pole generator rectifier circuit fault diagnosis method provided in this embodiment includes the following steps:

[0073] S1. According to the mechanical parameters and operating speed of the claw-pole generator to be tested, the theoretical main electromagnetic force spatial order and frequency information of the claw-pole generator to be tested are obtained using analytical formulas.

[0074] (1) Calculation of the radial air gap composite magnetic field B of the claw-pole generator without considering magnetic leakage and magnetic saturation r (θ, t, z), the magnetic field can be expressed by Equation B r (θ,t,z)=B a (θ,t,z)+B f (θ, t, z) is solved;

[0075] Among them, B a (θ, t, z) is the stator armature reaction magnetic field, B f (θ, t, z) is the rotor excitation magnetic field. Since the rectifier circuit fault has no direct effect on the rotor excitation magnetic field, only B is given. a The specific expression of (θ, t, z) is shown in formula (1):

[0076]

[0077] In the above formula, B a (θ, t, z) and the air gap composite permeance ∧(θ, t, z) are functions of time t, motor circumferential position θ and axial position z, m is the number of phases, N is the number of winding turns in each stator slot, I m is the armature phase current amplitude, φ is the initial current phase angle, ω e = pfr is the fundamental frequency electrical angular velocity of the current, ν is the harmonic order of the stator armature magnetomotive force, i is the harmonic order of the stator current, p is the number of pole pairs, f r is the motor speed. f The specific expressions of (θ, t, z) and ∧(θ, t, z) can be found in "Analytical Calculation Model of Air Gap Magnetic Field and Radial Electromagnetic Force of Electromagnetic Claw-Pole Generator". Zhong Hongmin et al. Apr. 2017. Vol 32 No. 7. p51-52;

[0078] (2) Then use the Maxwell tensor method to calculate the radial electromagnetic force P r , Where μ0 is the magnetic permeability of air;

[0079] After simplification, the main spatial orders and frequency information of electromagnetic forces from different sources can be obtained and organized into Table 1.

[0080] Table 1 Spatial order and frequency characteristics of radial electromagnetic force of claw-pole generator considering stator current harmonics

[0081]

[0082]

[0083] In Table 1, S is the number of stator slots of the claw-pole generator, p is the number of motor pole pairs, and f r is the motor mechanical frequency; μ1 and μ2 are the rotor magnetic field harmonic orders, η1 and η2 as well as n1 and n2 are the air gap synthetic permeability harmonic orders considering the pole claw structure and slotting effect, i is the stator current harmonic order, and the values ​​of the above parameters are all non-negative integers; and the stator magnetic field harmonic orders ν1 and ν2 in the m-phase AC motor are 2mk±1 (k=0,1,2,…).

[0084] In this embodiment, p=12, S=36, m=3, f r =6000rpm (i.e. 100Hz).

[0085] (3) Calculate the spatial order and frequency information of the main vibration wave;

[0086] The harmonics of the electromagnetic force with a spatial order of 0 constitute the main vibration factor. Therefore, the spatial order is set to 0, the constraints are obtained, the expression of the frequency is solved, and the 0th order electromagnetic force with a non-zero and lowest frequency is taken as the main vibration electromagnetic force.

[0087] Read the motor nameplate or the motor parameter description table issued by the motor manufacturer to obtain the phase number m, winding turns N, armature current amplitude Im, and pole pair number p of the claw-pole generator. Read the car speed instrument panel to obtain the current motor speed fr. Based on the above mechanical parameters and motor speed, the spatial order and frequency information of the main radial electromagnetic force of the claw-pole generator can be obtained.

[0088] Taking the second row of Table 1, "Interaction between the rotor magnetic field and the stator and rotor slots", as an example, let its spatial order expression be equal to zero, then there is a constraint condition (μ1+μ2)-(η1+η2)=-(n1+n2)S. Note that the frequency expression (μ1+μ2-η1+η2)pf r The difference with the left side of the constraint condition is only a multiple, so the frequency expression under this source can be simplified to -S(n1+n2)f r , substitute S=36, f r =100Hz, it is easy to know that the frequency at this time is -3600(n1+n2). Since n1 and n2 are both non-negative integers, |n1+n2|=1 is the theoretical main vibration harmonic frequency, that is, the spatial order and frequency information of the main vibration under this source is 0th order 3600Hz.

[0089] Using a similar method, the frequency information of the electromagnetic forces from other sources in Table 1 can also be obtained. After comparison, the 0th order 3600 Hz is still the harmonic component of the main vibration force with the smallest frequency. Therefore, the spatial order and frequency information of the main vibration harmonic of the 12-pole 36-slot claw-pole generator under the condition of a rotation frequency of 6000 rpm is 0th order 3600 Hz;

[0090] S2. Use a handheld sound level meter to collect the noise time domain signal emitted from the motor to be tested into the air sound field and import it into the computer through the serial port. The specific steps are as follows:

[0091] (1) Fix the sound level meter 5-10cm near the motor to be tested;

[0092] (2) Remove the protective cover from the sound level meter preamplifier head and assemble the microphone to the end of the preamplifier;

[0093] (3) Install batteries in the sound level meter, flip the switch to verify whether an undervoltage alarm occurs. If so, replace the batteries;

[0094] (4) Select frequency weighting A for the sound level meter and set the noise measurement range to 0-100 dB;

[0095] (5) Measure the ambient background noise and read the average background sound pressure level L p0 ;

[0096] (6) Control the mechanical speed of the motor to be tested to ω e , the excitation current is If . Read the average sound pressure level L under this condition pl , need to ensure e and I f Same as the theoretical derivation of S1, in this embodiment, control ω e (f r )=6000rpm,I f =3A;

[0097] (7) Compare the average sound pressure values ​​obtained in (5) and (6):

[0098] If L pl -L p0 ≥3dB, then proceed to the next step;

[0099] If L pl -L p0 <3dB, the measurement result is invalid. Take measures to reduce the background noise and repeat steps (5)-(7).

[0100] (8) Turn on the sound level meter to maintain the measurement mode and record the continuous time signal of the claw pole generator under specific working conditions. In this embodiment, the measurement time is maintained at 5 seconds;

[0101] (9) Depending on the model of the sound level meter, use the USB serial port or RS232 serial port to connect the sound level meter to the computer;

[0102] (10) Set the appropriate sampling frequency for the data receiving software provided by each sound level meter manufacturer. The sampling frequency should be no less than twice the bandwidth. Click "Transfer";

[0103] In this embodiment, the master oscillation frequency obtained in S1 is 3.6 kHz, so the bandwidth is selected to be 0-4.5 kHz and the sampling frequency is 9 kHz to ensure the integrity of the spectrum obtained by sampling.

[0104] (11) Export the discrete time data received by the data receiving software into an Excel table.

[0105] S3. Perform one-dimensional FFT (fast Fourier transform) processing on the collected noise time domain signal using Matlab program to obtain the noise frequency spectrum of the motor to be tested. The specific operation is as follows:

[0106] (1) Define the sampling frequency F in Matlab s (i.e., the sampling frequency in S2(10)), the signal length L (i.e., the duration of the sound level meter in the "hold measurement" mode in S2(8)), and the sampling period T = 1 / F s In this embodiment, according to S2(10) and S2(8), F is set s =9000, L=5;

[0107] (2) Use the csvread command to import the data in the Excel table obtained by S2 (11) as the input signal vector S of the FFT command;

[0108] (3) Use the fft(S) command to perform FFT transformation on the collected discrete time domain signal S, and obtain the transformed vector Y;

[0109] (4) Define the noise harmonic frequency domain as f=Fs*(0:(L / 2)) / L, and the noise harmonic single-side amplitude frequency as P=abs(Y / L)*(1:L / 2+1);

[0110] (5) Use plot(f,P) to plot the noise spectrum with the noise harmonic frequency domain f as the horizontal axis and the harmonic single-side amplitude frequency P as the vertical axis.

[0111] S4, observe the noise spectrum obtained in S3, identify the harmonic frequency with the largest noise amplitude, and compare it with the result of analytical calculation in S1. If the frequencies of the two peak noise harmonics are different, it is considered that a single-tube fault has occurred, and continue to operate S5-S7. Otherwise, it is considered that no single-tube fault has occurred in the claw-pole generator rectifier circuit;

[0112] Attached Figure 1 (b) Figure 1 (c) is the equivalent circuit diagram when a single-tube circuit breaker has different faults. Figure 3 That is, the noise spectrum diagram of the rectifier circuit in the embodiment when it is in normal operation and when a single tube fails.

[0113] Depend on Figure 3 It can be seen that before and after the rectifier circuit fails, the amplitudes of various low-frequency noises are greatly increased, especially the noise at 600Hz, which has exceeded the noise at 3600Hz and become the main noise.

[0114] S5. Read the rated output current I of the claw-pole generator from the motor nameplate d0 , and detect the output current I at the DC output end of the claw-pole generator rectifier circuit d ;Depend on Figure 4 (a), read I d0 =90A (i.e. 0Hz part of the current spectrum);

[0115] S6, if I d Compared with the rated output current I d0 If the reduction is within 10%, it is considered that a single tube is open circuited. Figure 4 (a) and Figure 4 (b) It can be seen that the DC output part (i.e. the 0Hz part of the current) measured when the circuit is broken is around 90A, which has no obvious change compared with the time without fault.

[0116] S7, if I d Compared with the rated output current I d0 If the reduction exceeds 10%, it is considered that a single tube short circuit fault has occurred. Figure 4 (a)(c) It can be seen that the DC output part measured during short circuit is about 20A, which is 78% weaker than that during normal operation.

[0117] It should be noted that, for the sake of convenience, the aforementioned method embodiments are all expressed as a series of action combinations, but those skilled in the art should know that the present invention is not limited to the described order of actions, because according to the present invention, certain steps can be performed in other orders or simultaneously.

[0118] Based on the same idea as the claw-pole generator rectifier circuit fault diagnosis method in the above embodiment, the present invention also provides a claw-pole generator rectifier circuit fault diagnosis system, which can be used to execute the above claw-pole generator rectifier circuit fault diagnosis method. For ease of explanation, the structural diagram of the claw-pole generator rectifier circuit fault diagnosis system embodiment only shows the parts related to the embodiment of the present invention. Those skilled in the art can understand that the illustrated structure does not constitute a limitation on the device, and may include more or fewer components than shown in the diagram, or combine certain components, or arrange the components differently.

[0119] See also Figure 5 In another embodiment of the present application, a claw-pole generator rectifier circuit fault diagnosis system 100 is provided, the system comprising a first acquisition module 101, a second acquisition module 102, a third acquisition module 103 and a comparison module 104;

[0120] The first acquisition module 101 is used to obtain the theoretical electromagnetic force spatial order and frequency information of the claw-pole generator to be tested by using an analytical method according to the mechanical parameters and operating speed of the claw-pole generator to be tested;

[0121] The second acquisition module 102 is used to acquire the noise time domain signal dissipated from the claw-pole generator to be tested into the air sound field;

[0122] The third acquisition module 103 is used to perform one-dimensional fast Fourier transform processing on the acquired noise time domain signal to obtain the noise frequency spectrum of the motor to be tested;

[0123] The comparison module 104 is used to identify the harmonic frequency with the largest noise amplitude from the noise spectrum obtained by the third acquisition module, and compare it with the result of analytical calculation by the first acquisition module. If the frequencies of the two peak noise harmonics are the same, it is considered that no single-tube fault occurs in the rectifier circuit of the claw-pole generator to be tested; if the frequencies of the two peak noise harmonics are different, it is considered that a single-tube fault occurs, and the following operations are continued:

[0124] Get the rated output current I of the claw-pole generator d0 , and detect the output current I at the DC output end of the claw-pole generator rectifier circuit d ;

[0125] If I d Compared with the rated output current I d0 If the weakening range is within 10%, it is considered that a single-tube open-circuit fault has occurred;

[0126] If I d Compared with the rated output current I d0 If the weakening exceeds 10%, it is considered that a single-tube short-circuit fault has occurred.

[0127] It should be noted that the claw-pole generator rectifier circuit fault diagnosis system of the present invention corresponds one-to-one to the claw-pole generator rectifier circuit fault diagnosis method of the present invention. The technical features and beneficial effects described in the embodiment of the above-mentioned claw-pole generator rectifier circuit fault diagnosis method are applicable to the embodiment of the claw-pole generator rectifier circuit fault diagnosis. For specific contents, please refer to the description in the embodiment of the method of the present invention, which will not be repeated here. This is hereby declared.

[0128] In addition, in the implementation of the claw-pole generator rectifier circuit fault diagnosis system in the above-mentioned embodiment, the logical division of each program module is only an example. In actual application, the above-mentioned functions can be assigned to different program modules as needed, for example, for the configuration requirements of the corresponding hardware or the convenience of software implementation. That is, the internal structure of the claw-pole generator rectifier circuit fault diagnosis system is divided into different program modules to complete all or part of the functions described above.

[0129] See also Figure 5 In one embodiment, an electronic device for implementing a claw-pole generator rectifier circuit fault diagnosis method is provided. The electronic device 200 may include a first processor 201, a first memory 202 and a bus, and may also include a computer program stored in the first memory 202 and executable on the first processor 201, such as a claw-pole generator rectifier circuit fault diagnosis program 203.

[0130] The first memory 202 includes at least one type of readable storage medium, and the readable storage medium includes flash memory, mobile hard disk, multimedia card, card-type memory (such as SD or DX memory, etc.), magnetic memory, disk, optical disk, etc. In some embodiments, the first memory 202 can be an internal storage unit of the electronic device 200, such as a mobile hard disk of the electronic device 200. In other embodiments, the first memory 202 can also be an external storage device of the electronic device 200, such as a plug-in mobile hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 200. Further, the first memory 202 can also include both an internal storage unit of the electronic device 200 and an external storage device. The first memory 202 can not only be used to store application software and various types of data installed in the electronic device 200, such as the code of the claw pole generator rectifier circuit fault diagnosis program 203, but also can be used to temporarily store data that has been output or is to be output.

[0131] In some embodiments, the first processor 201 may be composed of an integrated circuit, for example, a single packaged integrated circuit, or a plurality of packaged integrated circuits with the same or different functions, including one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and combinations of various control chips, etc. The first processor 201 is the control core (Control Unit) of the electronic device, and uses various interfaces and lines to connect various components of the entire electronic device, and executes various functions and processes data of the electronic device 200 by running or executing programs or modules stored in the first memory 202, and calling data stored in the first memory 202.

[0132] Figure 6 Only an electronic device with components is shown, and those skilled in the art will understand that Figure 6 The structure shown does not constitute a limitation on the electronic device 200 , and may include fewer or more components than shown in the figure, or combine certain components, or arrange the components differently.

[0133] The claw-pole generator rectifier circuit fault diagnosis program 203 stored in the first memory 202 in the electronic device 200 is a combination of multiple instructions. When executed in the first processor 201, the following can be achieved:

[0134] S1. According to the mechanical parameters and operating speed of the claw-pole generator to be tested, the theoretical electromagnetic force spatial order and frequency information of the claw-pole generator to be tested are obtained by using an analytical method;

[0135] S2, collecting the noise time domain signal dissipated from the claw-pole generator to be tested into the air sound field;

[0136] S3, performing one-dimensional fast Fourier transform processing on the collected noise time domain signal to obtain the noise frequency spectrum of the motor to be tested;

[0137] S4, for the noise spectrum obtained in step S3, identify the harmonic frequency with the largest noise amplitude, and compare it with the result of analytical calculation in S1. If the frequencies of the peak noise harmonics of the two are different, it is considered that a single-tube fault has occurred, and continue to perform steps S5-S7. Otherwise, it is considered that no single-tube fault has occurred in the rectifier circuit of the claw-pole generator to be tested;

[0138] S5. Get the rated output current I of the claw-pole generator d0 , and detect the output current I at the DC output end of the claw-pole generator rectifier circuit d ;

[0139] S6, if I d Compared with the rated output current I d0 If the weakening range is within 10%, it is considered that a single-tube open-circuit fault has occurred;

[0140] S7, if I d Compared with the rated output current I d0 If the weakening exceeds 10%, it is considered that a single-tube short-circuit fault has occurred.

[0141] Furthermore, if the module / unit integrated in the electronic device 200 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, and a read-only memory (ROM).

[0142] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0143] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0144] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for diagnosing a fault in a claw-pole generator rectifier circuit, characterized in that: The steps include: S1. According to the mechanical parameters and operating speed of the claw-pole generator to be tested, the theoretical electromagnetic force spatial order and frequency information of the claw-pole generator to be tested are obtained by using an analytical method; the analytical method performs Fourier decomposition on the stator and rotor magnetic potentials of the claw-pole generator under load and considers the slotting effect of the stator and rotor, and then uses Ohm's law under magnetic field conditions to obtain the air gap synthetic magnetic field; finally, the electromagnetic force is calculated according to the Maxwell stress tensor equation, and its frequency information is read after ignoring its time-invariant component and minor time-varying component; S2, collecting the noise time domain signal dissipated from the claw-pole generator to be tested into the air sound field; S3, performing one-dimensional fast Fourier transform processing on the collected noise time domain signal to obtain the noise frequency spectrum of the motor to be tested; S4, for the noise spectrum obtained in step S3, identify the harmonic frequency with the largest noise amplitude, and compare it with the result of analytical calculation in S1. If the frequencies of the peak noise harmonics of the two are different, it is considered that a single-tube fault has occurred, and continue to perform steps S5-S7. Otherwise, it is considered that no single-tube fault has occurred in the rectifier circuit of the claw-pole generator to be tested; S5. Get the rated output current I of the claw-pole generator d0 , and detect the output current I at the DC output end of the claw-pole generator rectifier circuit d ; S6, if I d Compared with the rated output current I d0 If the weakening range is within 10%, it is considered that a single-tube open-circuit fault has occurred; S7, if I d Compared with the rated output current I d0 If the weakening exceeds 10%, it is considered that a single-tube short-circuit fault has occurred.

2. The claw-pole generator rectifier circuit fault diagnosis method according to claim 1, characterized in that: The analytical method is specifically: S11. Calculate the radial air gap composite magnetic field B of the claw-pole generator without considering magnetic leakage and magnetic saturation r (θ,t,z),B r (θ,t,z)=B a (θ,t,z)+B f (θ,t,z); Among them, B a (θ, t, z) is the stator armature reaction magnetic field, B f (θ, t, z) is the rotor excitation magnetic field; S12. Use Maxwell tensor method to calculate radial electromagnetic force P r ,have Among them, μ0 is the magnetic permeability of air; S13. Calculate the spatial order and frequency information of the main vibration wave.

3. The claw-pole generator rectifier circuit fault diagnosis method according to claim 2, characterized in that: In step S11, since the rectifier circuit fault has no direct effect on the rotor excitation magnetic field, only the stator armature reaction magnetic field B a (θ, t, z) has an impact on the rectifier circuit fault, B a The calculation formula of (θ, t, z) is as follows: Among them, B a (θ, t, z) and the air gap composite permeance ∧(θ, t, z) are functions of time t, motor circumferential position θ and axial position z, m is the number of phases, N is the number of winding turns in each stator slot, I m is the armature phase current amplitude, is the initial current phase angle, ω e = pf r is the fundamental frequency electrical angular velocity of the current, ν is the harmonic order of the stator armature magnetomotive force, i is the harmonic order of the stator current, p is the number of pole pairs, f r is the motor speed.

4. The claw-pole generator rectifier circuit fault diagnosis method according to claim 2, characterized in that: In step S13, the electromagnetic force harmonics with a spatial order of 0 constitute the main vibration factor. Therefore, the spatial order is set to 0, the constraint conditions are obtained, the frequency expression is solved, and the 0th order electromagnetic force with a non-zero and lowest frequency is taken as the main vibration electromagnetic force wave; Read the motor nameplate or the motor parameter description table distributed by the motor manufacturer to obtain the phase number m, winding turns N, armature current amplitude Im, and pole pair number p of the claw-pole generator; read the automobile speed instrument panel to obtain the current motor speed fr; based on the above mechanical parameters and motor speed, obtain the spatial order and frequency information of the main radial electromagnetic force of the claw-pole generator; the spatial order and frequency information of the main radial electromagnetic force includes the spatial order and frequency information of the interaction between the stator magnetic field and the stator and rotor slots, the interaction between the rotor magnetic field and the stator and rotor slots, and the interaction between the stator and rotor magnetic fields and the stator and rotor slots.

5. The claw-pole generator rectifier circuit fault diagnosis method according to claim 1, characterized in that: Step S2 is specifically as follows: S21. Fix the sound level meter 5-10 cm near the claw-pole generator to be tested; S22. Remove the protective cover from the head of the sound level meter preamplifier and assemble the microphone to the end of the preamplifier; S23. Install batteries in the sound level meter, flip the switch to verify whether an undervoltage alarm occurs. If so, replace the batteries. S24. Select frequency weighting A for the sound level meter and set the noise measurement range to 0-100 dB; S25. Measure the ambient background noise and read the average ambient background sound pressure level L p0 ; S26, control the mechanical speed of the claw-pole generator to be tested to ω e , the excitation current is I f , read the average sound pressure level L under this condition pl , need to ensure e and I f Same as when S1 theory was derived; S27. Compare the average sound pressure values ​​obtained from S25 and S26: If L pl -L p0 ≥3dB, then proceed to the next step; If L pl -L p0 <3dB, the measurement result is invalid, and measures should be taken to reduce the background noise, and then repeat steps S25-S27; S28, turning on the sound level meter to maintain the measurement mode, and recording the continuous time signal of the claw pole generator under specific working conditions; S29. Depending on the model of the sound level meter, use the USB serial port or RS232 serial port to connect the sound level meter to the computer; S210. Set a suitable sampling frequency for the data receiving software provided by each sound level meter manufacturer. The sampling frequency should be no less than twice the bandwidth. Click "Transfer". S211. Export the discrete time data received by the data receiving software into an Excel table.

6. The claw-pole generator rectifier circuit fault diagnosis method according to claim 5, characterized in that: Step S3 is specifically as follows: S31. Define the sampling frequency F in Matlab s , signal length L, and obtain sampling period T = 1 / F s ; S32, using the csvread instruction to import the data in the Excel table obtained in step S211 as the input signal vector S of the FFT instruction; S33, use the fft(S) instruction to perform FFT transformation on the collected discrete time domain signal S, and obtain the transformed vector Y; S34, define the noise harmonic frequency domain f=Fs*(0:(L / 2)) / L, the noise harmonic single-side amplitude frequency is P=abs(Y / L)*(1:L / 2+1); S35. Use plot(f,P) to draw the noise spectrum with the noise harmonic frequency domain f as the horizontal coordinate and the harmonic single-side amplitude frequency P as the vertical coordinate.

7. A claw-pole generator rectifier circuit fault diagnosis system, characterized in that: A claw-pole generator rectifier circuit fault diagnosis method applied to any one of claims 1 to 6, comprising a first acquisition module, a second acquisition module, a third acquisition module and a comparison module; The first acquisition module is used to obtain the theoretical electromagnetic force spatial order and frequency information of the claw-pole generator to be tested by using an analytical method according to the mechanical parameters and operating speed of the claw-pole generator to be tested; The second acquisition module is used to collect the noise time domain signal dissipated from the claw-pole generator to be tested into the air sound field; The third acquisition module is used to perform one-dimensional fast Fourier transform processing on the collected noise time domain signal to obtain the noise frequency spectrum of the motor to be tested; The comparison module is used to identify the harmonic frequency with the largest noise amplitude from the noise spectrum obtained by the third acquisition module, and compare it with the result of analytical calculation by the first acquisition module. If the frequencies of the two peak noise harmonics are the same, it is considered that no single-tube fault occurs in the rectifier circuit of the claw-pole generator to be tested; if the frequencies of the two peak noise harmonics are different, it is considered that a single-tube fault occurs, and the following operations are continued: Get the rated output current I of the claw-pole generator d0 , and detect the output current I at the DC output end of the claw-pole generator rectifier circuit d ; If I d Compared with the rated output current I d0 If the weakening range is within 10%, it is considered that a single-tube open-circuit fault has occurred; If I d Compared with the rated output current I d0 If the weakening exceeds 10%, it is considered that a single-tube short-circuit fault has occurred.

8. An electronic device, characterized in that: The electronic device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores computer program instructions executable by the at least one processor, and the computer program instructions are executed by the at least one processor so that the at least one processor can execute the claw-pole generator rectifier circuit fault diagnosis method as described in any one of claims 1-6.

9. A computer-readable storage medium storing a program, characterized in that: When the program is executed by a processor, the claw-pole generator rectifier circuit fault diagnosis method according to any one of claims 1 to 6 is implemented.

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