CN111650509B - Fault judging method, device, computer equipment and medium for brushless excitation motor - Google Patents

Abstract

The invention discloses a fault judgment method and device of a brushless excitation motor, computer equipment and a medium. The method comprises the following steps: acquiring exciting current data in a stator exciting winding of a brushless exciting motor; carrying out Fourier analysis on the excitation current data, and calculating first effective values I under different preset harmonic frequencies ₁ And a second effective value I ₂ (ii) a Based on the first effective value I ₁ And said second effective value I ₂ And judging whether the grounding position of the stator excitation winding of the brushless excitation motor has a fault or not. The embodiment of the invention obtains a first effective value and a second effective value of the current stator exciting resistor under different preset harmonic frequencies by performing Fourier analysis on exciting current data, and judges whether a fault occurs at the grounding position of the stator exciting winding based on the two effective values. The embodiment of the invention has the characteristics of simple operation and intuitive judgment, and ensures the safety of the brushless excitation motor.

Description

Fault judging method, device, computer equipment and medium for brushless excitation motor

technical field

The invention relates to the technical field of relay protection of main equipment of a power system. More specifically, it relates to a fault judgment method, device, computer equipment and medium for a brushless excitation motor.

Background technique

The excitation system is an important part of large generators. The excitation system with excellent performance and high reliability is the basis for ensuring the safety of the generator and the stable operation of the power system. Compared with static excitation, the brushless excitation system cancels the carbon brushes and slip rings of the generator, which significantly improves the reliability of the excitation system. It is the preferred excitation method for large-capacity nuclear power units.

Taking the 11-phase toroidal brushless excitation motor commonly used in power plants as an example, the stator winding of the 11-phase toroidal brushless excitation motor often has two-point grounding faults, which brings serious safety hazards to the operation of the unit equipment and greatly affects the power Production.

However, in the prior art, there is no corresponding protection for the grounding points of the stator excitation winding of the brushless excitation motor, and there is no relevant research on the short-circuit fault protection of the exciter winding in the current published data. Due to the imperfect protection principle, the relevant regulations and standards have not put forward clear requirements for the internal fault protection of the stator and rotor windings of the brushless excitation motor.

Therefore, it is necessary to propose a new fault judging method, device, computer equipment and medium for a brushless excitation motor.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a fault judging method, device, computer equipment and medium for a brushless excitation motor, so as to solve at least one of the problems existing in the prior art;

To achieve the above object, the present invention adopts the following technical solutions:

A first aspect of the present invention provides a fault judgment method for a brushless excitation motor, comprising:

Obtain the excitation current data in the stator excitation winding of the brushless excitation motor;

performing Fourier analysis on the excitation current data, and calculating the first effective value I ₁ and the second effective value I ₂ under different preset harmonic frequencies;

Based on the first effective value _I1 and the second effective value _I2 , it is determined whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor.

Optionally, judging whether a fault occurs at the grounding of the stator field winding of the brushless excitation motor based on the first effective value I ₁ and the second effective value I ₂ further includes:

Determine a total effective value _I3 and determine an effective value ratio A of the first effective value _I1 and the _second effective value _I2 based on the first effective value _I1 and the second effective value I2;

Based on the total effective value _I3 and the effective value ratio A, it is determined whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor.

Optionally, judging whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor based on the total effective value _I3 and the effective value ratio A includes:

respectively acquiring the first current value and the second current value of the harmonic current under different preset harmonic frequencies;

determining a harmonic current threshold ξ ₁ at a preset harmonic frequency and a harmonic current ratio ξ ₂ of the first current value and the second current value based on the first current value and the second current value;

comparing the total effective value I ₃ with the harmonic current threshold ξ ₁ ; and comparing the effective value ratio A with the harmonic current ratio ξ ₂ at a preset harmonic frequency;

When the total effective value I ₃ is greater than the harmonic current threshold ξ ₁ , and the effective value ratio A is greater than the harmonic current ratio ξ ₂ at the preset harmonic frequency, the stator excitation winding of the brushless excitation motor A fault has occurred at the ground.

Optionally, the brushless excitation motor is an 11-phase brushless excitation motor, and the preset harmonic frequencies are 550 Hz and 1100 Hz.

Optionally, the harmonic current ratio ξ ₂ of the first current value and the second current value is a fixed value, and the fixed value is 2.

A second aspect of the present invention provides a judging device for implementing the above-mentioned fault judging method for a brushless excitation motor, the device comprising:

The data sampling module is used to obtain the excitation current data in the stator excitation winding of the brushless excitation motor;

an analysis and calculation module, configured to perform Fourier analysis on the excitation current data, and calculate the first effective value I ₁ and the second effective value I ₂ under different preset harmonic frequencies;

A fault judging module, configured to judge whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor based on the first effective value I ₁ and the second effective value I ₂ .

Optionally, the fault judging module includes:

an effective value and a ratio calculation unit for determining a total effective value _I3 and determining the first effective value _I1 and the second effective value based on the first effective value _I1 and the second effective value _I2 The rms value ratio A of I ₂ ;

A ground fault judging unit, configured to judge whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor based on the total effective value _I3 and the effective value ratio A.

Optionally, the ground fault judging unit includes:

a current acquisition unit, configured to acquire the first current value and the second current value of the harmonic current under different preset harmonic frequencies;

a current threshold ratio calculation unit, configured to determine a harmonic current threshold ξ ₁ at a preset harmonic frequency based on the first current value and the second current value, and the harmonics of the first current value and the second current value Current ratio ξ ₂ ;

a comparison and judgment unit, used for comparing the total effective value I ₃ with the harmonic current threshold ξ ₁ ; and for comparing the effective value ratio A with the harmonic current ratio ξ ₂ at a preset harmonic frequency; when When the total effective value I ₃ is greater than the harmonic current threshold ξ ₁ , and the effective value ratio A is greater than the harmonic current ratio ξ ₂ at the preset harmonic frequency, the comparison and judgment unit judges the stator of the brushless excitation motor Whether there is a fault at the ground of the field winding.

A third aspect of the present invention provides a computer device for implementing the above-mentioned fault judgment method for a brushless excitation motor, including:

It includes a memory, a processor and a computer program stored in the memory and running on the processor, characterized in that the processor implements the above-mentioned fault judging method when executing the program.

A fourth aspect of the present invention provides a computer-readable storage medium on which a computer program is stored, characterized in that, when the program is executed by a processor, the above-mentioned fault judging method is implemented.

The beneficial effects of the present invention are as follows:

In the embodiment of the present invention, by performing Fourier analysis on the excitation current data, the first effective value and the second effective value of the current stator excitation resistance at different preset harmonic frequencies are obtained, and the stator excitation winding is grounded based on the two effective values. to determine whether a fault has occurred. The embodiment of the present invention has the characteristics of simple operation and intuitive judgment, and ensures the safety of the brushless excitation motor.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 shows a flowchart of a protection method according to an embodiment of the present invention;

2 shows a flowchart of a protection method according to another embodiment of the present invention;

FIG. 3 shows a schematic diagram of the stator coordinates of the brushless excitation motor according to the embodiment of the present invention;

4 shows a schematic diagram of the analysis process of the harmonic current characteristics of the stator excitation current when the stator of the brushless excitation motor according to the embodiment of the present invention is grounded at two points;

FIG. 5 shows a structural block diagram of a computer device according to an embodiment of the present invention.

Detailed ways

In order to illustrate the present invention more clearly, the present invention will be further described below with reference to the preferred embodiments and accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present invention.

As shown in FIG. 1, an embodiment of the present invention discloses a fault judgment method for a brushless excitation motor, which specifically includes:

S1. Obtain the excitation current data in the stator excitation winding of the brushless excitation motor;

S2, performing Fourier analysis on the excitation current data, and calculating the first effective value I ₁ and the second effective value I ₂ under different preset harmonic frequencies;

S3. Based on the first effective value _I1 and the second effective value _I2 , determine whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor.

In the embodiment of the present invention, by performing Fourier analysis on the excitation current data, the first effective value and the second effective value of the current stator excitation resistance at different preset harmonic frequencies are obtained, and the stator excitation winding is grounded based on the two effective values. to determine whether a fault has occurred. The embodiment of the present invention has the characteristics of simple operation and intuitive judgment, and ensures the safety of the brushless excitation motor.

In a specific example, the excitation current data in this embodiment can be obtained by using a CT (current transformer) or a Hall element;

In some optional implementations of this embodiment, S3 further includes:

S31. Determine a total effective value _I3 and determine an effective value ratio A between the first effective value _I1 and the second effective value _I2 based on the first effective value _I1 and the second effective value _I2 ;

S32 , based on the total effective value _I3 and the effective value ratio A, determine whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor.

In some optional implementations of this embodiment, S32 includes:

S321, respectively obtaining the first current value and the second current value of the harmonic current under different preset harmonic frequencies;

S322. Determine, based on the first current value and the second current value, a harmonic current threshold ξ ₁ at a preset harmonic frequency, and a harmonic current ratio ξ ₂ between the first current value and the second current value;

S323. Compare the total effective value I ₃ with the harmonic current threshold ξ ₁ ; and compare the effective value ratio A with the harmonic current ratio ξ ₂ at a preset harmonic frequency;

When the total effective value I ₃ is greater than the harmonic current threshold ξ ₁ , and the effective value ratio A is greater than the harmonic current ratio ξ ₂ at the preset harmonic frequency, the stator excitation winding of the brushless excitation motor A fault has occurred at the ground.

In some optional implementations of this embodiment, the brushless excitation motor is an 11-phase brushless excitation motor, and the preset harmonic frequencies are 550 Hz and 1100 Hz.

In some optional implementations of this embodiment, the harmonic current ratio ξ ₂ of the first current value and the second current value is a fixed value, and the fixed value is 2.

In an optional embodiment of the present invention, the fault condition is set as: when the total effective value I ₃ is greater than the harmonic current threshold ξ ₁ , and the effective value ratio A is greater than a preset harmonic frequency When the harmonic current ratio is ξ ₂ , that is, when I ₃ ≥ξ ₁ and A>ξ ₂ , it is judged that the 11-phase annular brushless exciter has a two-point grounding fault on the stator; where ξ ₁ is the preset 550Hz and 1100Hz Threshold threshold for the sum of harmonic currents, which should be able to reliably avoid the sum of 550Hz and 1100Hz harmonic currents under various operating conditions during normal operation; ξ ₂ is the preset value of the ratio of 550Hz and 1100Hz harmonic currents , the fixed value can be fixed as 2.

2 shows a computer-based protection method for a brushless excitation motor according to another embodiment of the present invention, and the method is performed in the computer according to the following steps in sequence:

In step (1), the excitation current in the stator excitation winding is sampled at the brushless excitation motor end, and the sampled data is sent to the computer;

Step (2), carry out Fourier analysis to the sampled excitation current data, take the harmonic of 550Hz and the harmonic of 1100Hz, and calculate its effective value as I ₁ and I ₂ ;

Step (3), obtain the effective value I ₃ of the two: I ₃ =I ₁ +I ₂ ;

Step (4), obtain the ratio of the two effective values as A: A=I ₁ /I ₂

Step (5), fault judgment:

When I ₃ ≥ξ ₁ and A>ξ ₂ , it is judged that the 11-phase annular brushless exciter has a two-point ground fault of the stator; where ξ ₁ is the preset threshold value of the sum of harmonic currents of 550Hz and 1100Hz, It should be able to reliably avoid the sum of 550Hz and 1100Hz harmonic currents under various working conditions during normal operation; ξ ₂ is the preset value of the ratio of 550Hz and 1100Hz harmonic currents, which can be fixed as 2.

In this embodiment, when the 11-phase brushless exciter has a two-point grounding fault on the stator, the high-frequency components of 550Hz and 1100Hz in the stator excitation current increase significantly, and the effective value of the harmonic current at 550Hz is significantly larger than the harmonic at 1100Hz. Therefore, the embodiment of the present invention only needs to collect the stator excitation current in the stator excitation winding from the brushless excitation motor end, and then obtain the steady-state effective value of the harmonic current of the excitation current at 550Hz and 1100Hz. The sum of the two is compared with the setting threshold value, and a simple and effective judgment of the stator two-point ground fault can be realized.

The principle of the present invention is as follows, still taking the 11-phase annular brushless excitation motor as an example:

As shown in Figure 3, assuming that the w-turn excitation winding under the first pole is shorted to the ground, when the DC current I flows through the w-turn excitation winding, a rectangular wave magnetomotive force will be generated. In the interval of the motor circumference [-5π, 5π], the rectangular wave magnetomotive force F(x) is:

Since the rectangular wave magnetomotive force is symmetrical to the rotor coordinate d axis, there is only a cosine term in the above formula. where:

In the formula, F _k is the magnetomotive force of the k-th harmonic, and β is the short-distance ratio of the excitation coil. Since the excitation winding of the salient pole machine can be regarded as a concentrated full-pitch winding, β=1.

therefore:

It can be seen from the above formula that when k is an even number, F _k is equal to zero. Therefore, the magnetomotive force generated by the excitation fault additional circuit does not contain even harmonics, but includes fundamental, odd harmonics and fractional harmonics such as 1/5 and 2/5. These magnetomotive forces acting in the non-uniform air gap will generate a series of harmonic magnetic fields, taking k=ν/5 (ν=1,2...) order magnetomotive force as an example:

B(x)=F _k (x) λ _δ (x) (4)

Different from the hidden pole generator, the air gap permeability coefficient when the influence of teeth and slots is not considered:

therefore:

It can be seen from the above formula that the magnetic field generated by the DC component current of the additional circuit of the excitation fault contains fundamental, odd and fractional harmonics. Among them, the term containing λ ₀ represents the space magnetic field of the same order as the excitation magnetomotive force, and due to the influence of the air-gap permeability harmonics, the air-gap magnetic field also contains (ν/5±2l) order harmonics (l=0, 1,2…), these magnetic fields all rotate synchronously with the rotor.

When the stator two-point ground fault occurs, the fractional electromotive force in the armature winding will be superimposed on the fundamental wave and odd-numbered electromotive force during normal operation, which will cause the change of the commutation mode of the load rotating rectifier. But no matter how the commutation mode of the rotating rectifier changes, because each fractional electromotive force will each induce harmonic currents of corresponding frequencies in the armature phase current.

The μ _1/5 harmonic current of the k-th phase armature winding can be expressed as:

where: μ ₁ , n is a constant; t is time;

The harmonic current will generate each harmonic magnetomotive force, and the space magnetomotive force generated by the _{one -} phase winding will be Fourier decomposed. The v ₁ /5th space harmonic magnetic potential generated by the /5th harmonic current can be expressed as:

The expression of the magnetic potential generated by the k-th phase winding can be obtained as

where α is the electrical angle;

The magnetic potential generated by each phase winding is a pulsed magnetic potential, which can be decomposed into positive and reversed magnetic potentials, and the magnetic potentials of the same direction are synthesized respectively. The forward and reverse magnetic potentials are:

After further mathematical derivation (complex process is omitted), the magnitudes of the positive and reverse magnetic potentials can be expressed as:

From equations (12) and (13), it can be known that f _v∑ is not zero if and only if v ₁ =11n ₂ +μ ₁ (n ₂ ∈N), and there are only 11n ₂ +μ ₁ times in the armature reaction Forward rotation component. Similarly, if and only when v ₁ =11n ₂ -μ ₁ (n ₂ ∈N), f _vΣ is not zero, and only 11n ₂ -μ ₁ reversal components exist in the armature reaction.

When the stator is grounded at two points, the analysis process of the harmonic current characteristics of the stator excitation current is shown in Figure 4. The v _1/11 harmonic magnetomotive force generated by the μ _1/11 harmonic current in the armature winding, the number of pole pairs is v _1/11 , and its forward rotation component speed is ₁ times the synchronous speed μ ₁ /v , the relative stator speed is |μ ₁ /v ₁ -1| times, and the frequency of the electromotive force induced in the stator is |μ ₁ -v ₁ |/11 times of the fundamental wave, that is, 550 times the harmonic potential.

Through the above calculation and analysis, it is explained that the specific harmonics of the excitation current can reflect the two-point grounding fault of the excitation winding of the exciter stator. The brushless excitation motor terminal collects the stator excitation current in the stator excitation winding, and then obtains the steady-state effective value of the harmonic current of the excitation current at 550Hz and 1100Hz, obtains the sum of the two, and compares it with the setting threshold to achieve Two-point ground fault judgment of stator winding of brushless exciter. The method for judging the two-point grounding fault of the stator winding of the brushless exciter proposed by the invention is simple and effective.

Another embodiment of the present invention discloses a fault judging device for a brushless excitation motor, the device comprising:

The data sampling module is used to obtain the excitation current data in the stator excitation winding of the brushless excitation motor;

an analysis and calculation module, configured to perform Fourier analysis on the excitation current data, and calculate the first effective value I ₁ and the second effective value I ₂ under different preset harmonic frequencies;

A fault judging module, configured to judge whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor based on the first effective value I ₁ and the second effective value I ₂ .

In some optional implementations of this embodiment, the fault judging module includes:

an effective value and a ratio calculation unit for determining a total effective value _I3 and determining the first effective value _I1 and the second effective value based on the first effective value _I1 and the second effective value _I2 The rms value ratio A of I ₂ ;

A ground fault judging unit, configured to judge whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor based on the total effective value _I3 and the effective value ratio A.

In some optional implementation manners of this embodiment, the ground fault judgment unit includes:

a current acquisition unit, configured to acquire the first current value and the second current value of the harmonic current under different preset harmonic frequencies;

a current threshold ratio calculation unit, configured to determine a harmonic current threshold ξ ₁ at a preset harmonic frequency based on the first current value and the second current value, and the harmonics of the first current value and the second current value Current ratio ξ ₂ ;

a comparison and judgment unit, used for comparing the total effective value I ₃ with the harmonic current threshold ξ ₁ ; and for comparing the effective value ratio A with the harmonic current ratio ξ ₂ at a preset harmonic frequency; when When the total effective value I ₃ is greater than the harmonic current threshold ξ ₁ , and the effective value ratio A is greater than the harmonic current ratio ξ ₂ at the preset harmonic frequency, the comparison and judgment unit judges the stator of the brushless excitation motor Whether there is a fault at the ground of the field winding.

In some optional implementations of this embodiment, the brushless excitation motor is an 11-phase brushless excitation motor, and the preset harmonic frequencies are 550 Hz and 1100 Hz.

In some optional implementation manners of this embodiment, the harmonic current ratio between the first current value and the second current value is a fixed value, which is a fixed value of 2.

It should be noted that the principle and work flow of the computer-based brushless excitation motor protection device provided in this embodiment are similar to the above-mentioned computer-based brushless excitation motor protection method. Repeat.

Another embodiment of the present invention provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, realizes: acquiring excitation current data in a stator excitation winding of a brushless excitation motor; Fourier analysis is performed on the excitation current data, and the first effective value I ₁ and the second effective value I ₂ under different preset harmonic frequencies are calculated; based on the first effective value I ₁ and the second effective value I ₂ judges whether there is a fault at the ground of the stator field winding of the brushless field motor.

In practical applications, the computer-readable storage medium may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, or a combination of any of the above. More specific examples (a non-exhaustive list) of computer readable storage media include: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read only memory (ROM), Erasable programmable read only memory (EPROM or flash memory), optical fiber, portable compact disk read only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In this embodiment, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

A computer-readable signal medium may include a propagated data signal in baseband or as part of a carrier wave, with computer-readable program code embodied thereon. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device .

Program code embodied on a computer readable medium may be transmitted using any suitable medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for carrying out operations of the present invention may be written in one or more programming languages, including object-oriented programming languages—such as Java, Smalltalk, C++, but also conventional Procedural programming language - such as the "C" language or similar programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (eg, using an Internet service provider through Internet connection).

As shown in FIG. 5, another embodiment of the present invention provides a schematic structural diagram of a computer device. The computer device 12 shown in FIG. 5 is only an example, and should not impose any limitation on the function and scope of use of the embodiments of the present invention.

As shown in FIG. 5, computer device 12 takes the form of a general-purpose computing device. Components of computer device 12 may include, but are not limited to, one or more processors or processing units 16 , system memory 28 , and a bus 18 connecting various system components including system memory 28 and processing unit 16 .

Bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of a variety of bus structures. By way of example, these architectures include, but are not limited to, Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect ( PCI) bus.

Computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by computer device 12, including both volatile and nonvolatile media, removable and non-removable media.

System memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and/or cache memory 32 . Computer device 12 may further include other removable/non-removable, volatile/non-volatile computer system storage media. For example only, storage system 34 may be used to read and write to non-removable, non-volatile magnetic media (not shown in FIG. 5, commonly referred to as a "hard disk drive"). Although not shown in Figure 5, a disk drive may be provided for reading and writing to removable non-volatile magnetic disks (eg "floppy disks"), as well as removable non-volatile optical disks (eg CD-ROM, DVD-ROM) or other optical media) to read and write optical drives. In these cases, each drive may be connected to bus 18 through one or more data media interfaces. Memory 28 may include at least one program product having a set (eg, at least one) of program modules configured to perform the functions of various embodiments of the present invention.

A program/utility 40 having a set (at least one) of program modules 42, which may be stored, for example, in memory 28, such program modules 42 including, but not limited to, an operating system, one or more application programs, other program modules, and program data , each or some combination of these examples may include an implementation of a network environment. Program modules 42 generally perform the functions and/or methods of the described embodiments of the present invention.

Computer device 12 may also communicate with one or more external devices 14 (eg, keyboard, pointing device, display 24, etc.), may also communicate with one or more devices that enable a user to interact with computer device 12, and/or communicate with Any device (eg, network card, modem, etc.) that enables the computer device 12 to communicate with one or more other computing devices. Such communication may take place through input/output (I/O) interface 22 . Also, the computer device 12 may communicate with one or more networks (eg, a local area network (LAN), a wide area network (WAN), and/or a public network such as the Internet) through a network adapter 20 . As shown in FIG. 5 , network adapter 20 communicates with other modules of computer device 12 via bus 18 . It should be understood that, although not shown in FIG. 5, other hardware and/or software modules may be used in conjunction with computer device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tapes drives and data backup storage systems, etc.

The processor unit 16 executes various functional applications and data processing by running the programs stored in the system memory 28 , for example, implementing a fault judgment method for a brushless excitation motor provided by the embodiment of the present invention.

Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Changes or changes in other different forms cannot be exhausted here, and all obvious changes or changes derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims (8)

1. a fault judging method of brushless excitation motor, is characterized in that, comprises: Obtain the excitation current data in the stator excitation winding of the brushless excitation motor; performing Fourier analysis on the excitation current data, and calculating the first effective value I ₁ and the second effective value I ₂ under different preset harmonic frequencies; Based on the first effective value _I1 and the second effective value _I2 , determine whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor; Wherein, judging whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor based on the first effective value I ₁ and the second effective value I ₂ further includes: Determine a total effective value _I3 and determine an effective value ratio A of the first effective value _I1 and the _second effective value _I2 based on the first effective value _I1 and the second effective value I2; Based on the total effective value _I3 and the effective value ratio A, determine whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor; Wherein, judging whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor based on the total effective value _I3 and the effective value ratio A includes: respectively acquiring the first current value and the second current value of the harmonic current under different preset harmonic frequencies; determining a harmonic current threshold ξ ₁ at a preset harmonic frequency and a harmonic current ratio ξ ₂ of the first current value and the second current value based on the first current value and the second current value; comparing the total effective value I ₃ with the harmonic current threshold ξ ₁ ; and comparing the effective value ratio A with the harmonic current ratio ξ ₂ at a preset harmonic frequency; When the total effective value I ₃ is greater than the harmonic current threshold ξ ₁ , and the effective value ratio A is greater than the harmonic current ratio ξ ₂ at the preset harmonic frequency, the stator excitation winding of the brushless excitation motor A fault has occurred at the ground. 2 . The method according to claim 1 , wherein the brushless excitation motor is an 11-phase brushless excitation motor, and the preset harmonic frequencies are 550 Hz and 1100 Hz. 3 . 3 . The method according to claim 1 , wherein the harmonic current ratio ξ ₂ of the first current value and the second current value is a fixed value, and the fixed value is 2. 4 . 4. A fault judging device for a brushless excitation motor for performing the method according to any one of claims 1-3, wherein the device comprises: The data sampling module is used to obtain the excitation current data in the stator excitation winding of the brushless excitation motor; an analysis and calculation module, configured to perform Fourier analysis on the excitation current data, and calculate the first effective value I ₁ and the second effective value I ₂ under different preset harmonic frequencies; A fault judging module, configured to judge whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor based on the first effective value I ₁ and the second effective value I ₂ . 5. The device according to claim 4, wherein the fault judging module comprises: an effective value and a ratio calculation unit for determining a total effective value _I3 and determining the first effective value _I1 and the second effective value based on the first effective value _I1 and the second effective value _I2 The rms value ratio A of I ₂ ; A ground fault judging unit, configured to judge whether a fault occurs at the grounding of the stator excitation winding of the brushless excitation motor based on the total effective value _I3 and the effective value ratio A. 6. The device according to claim 5, wherein the ground fault judging unit comprises: a current acquisition unit, configured to acquire the first current value and the second current value of the harmonic current under different preset harmonic frequencies; a current threshold ratio calculation unit, configured to determine a harmonic current threshold ξ ₁ at a preset harmonic frequency based on the first current value and the second current value, and the harmonics of the first current value and the second current value Current ratio ξ ₂ ; a comparison and judgment unit, used for comparing the total effective value I ₃ with the harmonic current threshold ξ ₁ ; and for comparing the effective value ratio A with the harmonic current ratio ξ ₂ at a preset harmonic frequency; when When the total effective value I ₃ is greater than the harmonic current threshold ξ ₁ , and the effective value ratio A is greater than the harmonic current ratio ξ ₂ at the preset harmonic frequency, the comparison and judgment unit judges the stator of the brushless excitation motor Whether there is a fault at the ground of the field winding. 7. A computer equipment comprising a memory, a processor and a computer program that is stored on the memory and can be run on the processor, wherein the processor implements any one of claims 1-3 when the processor executes the program. one of the methods described. 8. A computer-readable storage medium on which a computer program is stored, characterized in that, when the program is executed by a processor, the method according to any one of claims 1-3 is implemented.

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