CN114441962B

CN114441962B - Method and system for diagnosing internal faults of stator and rotor windings of electro-magnetic synchronous motor

Info

Publication number: CN114441962B
Application number: CN202210135097.1A
Authority: CN
Inventors: 孙宇光; 尹超; 李玮珍
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2022-02-14
Filing date: 2022-02-14
Publication date: 2024-06-18
Anticipated expiration: 2042-02-14
Also published as: CN114441962A

Abstract

The application relates to a method and a system for diagnosing internal faults of stator and rotor windings of an electro-magnetic synchronous motor, wherein at least one detection coil is arranged in the electro-magnetic synchronous motor, and the method comprises the following steps: collecting the actual port voltage of at least one detection coil, extracting at least one fault characteristic from the actual port voltage, and calculating the protection sensitivity of the internal short-circuit fault of the stator and the monitoring sensitivity of the inter-turn short-circuit fault of the rotor exciting winding based on the at least one fault characteristic; and diagnosing the internal fault type of the stator winding and the rotor winding of the electrically excited synchronous motor according to the protection sensitivity and/or the monitoring sensitivity, wherein the fault type is the internal short-circuit fault of the stator when the protection sensitivity is greater than or equal to a first preset threshold value, and the fault type is the turn-to-turn short-circuit fault of the exciting winding when the monitoring sensitivity is greater than or equal to a second preset threshold value. Therefore, the detection function of internal faults of the stator and rotor windings is realized, the fault type is diagnosed on line by utilizing an algorithm program, and the sensitivity of fault detection is improved.

Description

Method and system for diagnosing internal faults of stator and rotor windings of electro-magnetic synchronous motor

Technical Field

The application relates to the technical field of detection of power systems, in particular to a method and a system for diagnosing internal faults of stator and rotor windings of an electrically excited synchronous motor.

Background

As basic equipment for electric energy production and application, the safe and reliable operation of the synchronous motor has great significance. Internal shorting of stator windings is a common, very damaging fault in synchronous motors that must be removed in time to avoid or mitigate fault damage.

Because of the common influence of the bad processing technology in the manufacturing process and the actions of various machines, electricity, heat and the like in the operation, the inter-turn short circuit fault of the exciting winding caused by the fact that inter-turn insulation is easy to be worn is also a common fault of the synchronous motor, and the problems of obvious increase of exciting current, reduction of reactive power output by a generator, aggravation of vibration of a unit and the like are caused although the damage of the internal short circuit of a stator is not serious and the internal short circuit of the stator is required to be cut off immediately. If the turn-to-turn short circuit fault of the exciting winding continues to develop, the local overheating at the short circuit point can also cause the fault to evolve into one-point or even two-point grounding fault of the rotor, damage the rotor core and possibly cause magnetization of a large shaft of the rotor, and the journal and the bearing bush can be burnt under serious conditions, so that the safety operation of the unit is greatly threatened.

The current transformer is large in size and large in number, is difficult to be applied to limited spaces such as a mobile energy platform, and the rated parameters of the used transformer and the setting value of protection actions are obtained through actually measuring inherent unbalanced current of normal operation working conditions of a motor (under the condition of maximum load), so that small workload is brought to maintenance work.

Disclosure of Invention

The application provides a method and a system for diagnosing internal faults of a stator winding and a rotor winding of an electrically excited synchronous motor, which are used for solving the problems that when internal faults of the stator winding and the rotor winding of the electrically excited synchronous motor are detected, current transformers which are required to be installed are large in size and large in number, are difficult to be applied to limited spaces such as a mobile energy platform and the like, and the maintenance workload is increased.

An embodiment of a first aspect of the present application provides a method for diagnosing internal faults of stator windings and rotor windings of an electrically excited synchronous motor, where at least one detection coil is disposed in the electrically excited synchronous motor, and the method includes the following steps:

Acquiring an actual port voltage of the at least one detection coil;

extracting at least one fault feature from the actual port voltage of the at least one detection coil, and calculating the protection sensitivity of the stator internal short-circuit fault and the monitoring sensitivity of the rotor exciting winding turn-to-turn short-circuit fault based on the at least one fault feature; and

And diagnosing the internal fault type of the stator winding and the rotor winding of the electric excitation synchronous motor according to the protection sensitivity and/or the monitoring sensitivity, wherein the internal fault type of the stator winding is a stator internal short-circuit fault when the protection sensitivity of the stator internal short-circuit fault is greater than or equal to a first preset threshold value, and the internal fault type of the stator winding is an excitation winding inter-turn short-circuit fault when the monitoring sensitivity of the rotor excitation winding inter-turn short-circuit fault is greater than or equal to a second preset threshold value.

According to one embodiment of the present application, the protection sensitivity calculation formula of the stator internal short circuit fault is as follows:

Wherein, U _d,1 is the fundamental effective value in the actual port voltage, U _d,3 is the 3 rd harmonic effective value in the actual port voltage, U _d,5 is the 5th harmonic effective value in the actual port voltage, k is a natural number,K _tol.1 is a reliable coefficient of stator internal short-circuit protection, n is an actual running rotating speed of the electric excitation synchronous motor, I _fd is an exciting current direct current component in the actual running of the electric excitation synchronous motor, n _normal is a rotating speed of the electric excitation synchronous motor in normal running, I _fd.normal is an exciting current of the electric excitation synchronous motor in normal running, U _d.normal,1 is a fundamental wave effective value of the actual port voltage in normal running of the electric excitation synchronous motor, U _d.normal,3 is a3 rd harmonic effective value of the actual port voltage in normal running of the electric excitation synchronous motor, and U _d.normal,5 is a 5 th harmonic effective value of the actual port voltage in normal running of the electric excitation synchronous motor.

According to one embodiment of the application, the calculation formula of the monitoring sensitivity of the rotor exciting winding turn-to-turn short circuit fault is as follows:

Wherein, P is the pole pair number of the electrically excited synchronous motor, U _d,K/P is the effective value of K/P harmonic in the actual port voltage, K is a natural number and is not an integer multiple of P,/>K _tol.2 is the reliable coefficient of the excitation winding turn-to-turn short circuit monitoring, n is the actual running rotating speed of the electric excitation synchronous motor, I _fd is the exciting current direct current component in the actual running of the electric excitation synchronous motor, n _normal is the rotating speed of the electric excitation synchronous motor in normal running, I _fd.normal is the exciting current of the electric excitation synchronous motor in normal running, and U _d.normal,K/P is the effective value of the K/P harmonic of the actual port voltage in normal running of the electric excitation synchronous motor.

According to an embodiment of the present application, the diagnosing the internal fault type of the stator and rotor windings of the electro-magnetic synchronous motor according to the protection sensitivity and/or the monitoring sensitivity further includes:

Acquiring a first correction value of a protection threshold value of the internal short circuit of the stator and/or a second correction value of an alarm threshold value of the turn-to-turn short circuit of the rotor excitation winding;

Correcting the protection threshold value of the internal short circuit of the stator based on the first correction value, and correcting the alarm threshold value of the turn-to-turn short circuit of the rotor exciting winding based on the second correction value;

and identifying the internal fault type of the stator and rotor windings of the electro-magnetic synchronous motor according to the corrected protection threshold value of the internal short circuit of the stator and/or the alarm threshold value of the inter-turn short circuit of the rotor excitation winding.

According to one embodiment of the present application, before obtaining the first correction value of the protection threshold value of the stator internal short circuit and/or the second correction value of the alarm threshold value of the rotor excitation winding turn-to-turn short circuit, the method further comprises:

Detecting and recognizing whether the protection sensitivity of the stator internal short-circuit fault is smaller than the first preset threshold value and the monitoring sensitivity of the rotor exciting winding inter-turn short-circuit fault is smaller than the second preset threshold value, or whether the protection sensitivity of the stator internal short-circuit fault is larger than or equal to a third preset threshold value or whether the monitoring sensitivity of the rotor exciting winding inter-turn short-circuit fault is larger than or equal to a fourth preset threshold value;

If so, taking the action quantity of the stator internal short-circuit fault as the first correction value, and taking the monitoring quantity of the rotor exciting winding inter-turn short-circuit fault as the second correction value;

the third preset threshold value is smaller than the first preset threshold value, and the fourth preset threshold value is smaller than the second preset threshold value.

According to an embodiment of the present application, the calculation formula for correcting the protection threshold value of the internal short circuit of the stator based on the first correction value and correcting the alarm threshold value of the inter-turn short circuit of the exciting winding of the rotor based on the second correction value is as follows:

according to one embodiment of the application, the at least one fault signature comprises: odd harmonics and fractional harmonics.

According to one embodiment of the application, the stator and rotor winding internal fault diagnosis method of the electro-magnetic synchronous motor further comprises the following steps:

and outputting the internal fault diagnosis result of the stator and rotor windings of the electro-magnetic synchronous motor.

An embodiment of a second aspect of the present application provides a stator-rotor winding internal fault diagnosis system of an electrically excited synchronous motor, in which at least one detection coil is disposed, wherein the system includes:

The acquisition module is used for acquiring the actual port voltage of the at least one detection coil;

The calculation module is used for extracting at least one fault characteristic from the actual port voltage of the at least one detection coil and calculating the protection sensitivity of the internal short-circuit fault of the stator and the monitoring sensitivity of the turn-to-turn short-circuit fault of the rotor exciting winding based on the at least one fault characteristic; and

The diagnosis module is used for diagnosing the internal fault type of the stator winding and the rotor winding of the electric excitation synchronous motor according to the protection sensitivity and/or the monitoring sensitivity, wherein the internal fault type of the stator winding is the internal short-circuit fault of the stator when the protection sensitivity of the internal short-circuit fault of the stator is greater than or equal to a first preset threshold value, and the internal fault type of the stator winding is the turn-to-turn short-circuit fault of the excitation winding when the monitoring sensitivity of the turn-to-turn short-circuit fault of the rotor is greater than or equal to a second preset threshold value.

According to one embodiment of the application, the diagnostic module is further configured to:

identifying the internal fault type of the stator and rotor windings of the electro-magnetic synchronous motor according to the corrected protection threshold value of the internal short circuit of the stator and/or the alarm threshold value of the inter-turn short circuit of the rotor excitation winding;

before obtaining the first correction value of the protection threshold value of the stator internal short circuit and/or the second correction value of the alarm threshold value of the rotor excitation winding turn-to-turn short circuit, the diagnosis module is further configured to:

The third preset threshold value is smaller than the first preset threshold value, the fourth preset threshold value is smaller than the second preset threshold value, the protection threshold value of the internal short circuit of the stator is corrected based on the first correction value, and the alarm threshold value of the inter-turn short circuit of the rotor exciting winding is corrected based on the second correction value, wherein the calculation formula is as follows:

According to one embodiment of the present application, the stator and rotor winding internal fault diagnosis system of the electro-magnetic synchronous motor further comprises:

and the output module is used for outputting the internal fault diagnosis result of the stator and rotor windings of the electro-magnetic synchronous motor.

An embodiment of a third aspect of the present application provides an electronic device, including: the device comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the program to realize the stator and rotor winding internal fault diagnosis method of the electrically excited synchronous motor.

An embodiment of a fourth aspect of the present application provides a computer-readable storage medium having stored thereon a computer program that is executed by a processor for implementing the stator-rotor winding internal fault diagnosis method of an electrically excited synchronous motor as described in the above embodiment.

Therefore, the stator and rotor winding internal fault diagnosis method of the electro-magnetic synchronous motor has the following advantages:

(1) The internal faults of the stator winding and the rotor winding of the synchronous motor can be detected and diagnosed in real time by collecting the voltage data of the built-in detection coil port of the synchronous motor in real time and analyzing and processing signals, and the diagnosis result is visible in real time;

(2) The method has the advantages that the threshold values of actions and alarms can be automatically set on line, the problem of fault monitoring when the inherent unbalance factors (such as the eccentric degree of the rotor) of the synchronous motor are changed is solved, the reliability and the sensitivity of fault detection are not affected, and the operation and maintenance workload is reduced;

(3) The fault detection and diagnosis can be performed based on a small voltage signal (of a built-in detection coil of the synchronous motor), and electromagnetic interference and insulation damage can not be caused to the motor.

Additional aspects and advantages of the application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the application.

Drawings

The foregoing and/or additional aspects and advantages of the application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

fig. 1 is a flowchart of a method for diagnosing internal faults of stator and rotor windings of an electrically excited synchronous motor according to an embodiment of the present application;

fig. 2 is a diagram illustrating a structure of a stator-rotor winding internal fault diagnosis apparatus of an electro-magnetic synchronous motor according to an embodiment of the present application;

Fig. 3 is a diagram showing an example distribution of 5 detection coils in a six-phase commutated motor according to an embodiment of the present application;

Fig. 4 is an exemplary diagram of a stator and rotor winding internal fault diagnosis display panel of an electro-magnetic synchronous motor according to an embodiment of the present application;

FIG. 5 is an exemplary diagram of a stator winding connection and internal lead taps for a six-phase commutated motor according to one embodiment of the present application;

FIG. 6 is an exemplary diagram of an internal tap of a field winding of a six-phase commutated motor provided in accordance with one embodiment of the present application;

FIG. 7 is a graph showing the result of providing a turn-to-turn short circuit of stator b1 to N1 according to one embodiment of the present application;

FIG. 8 is a graph showing the result of a 12.5% turn-to-turn short circuit of the field winding according to one embodiment of the present application;

Fig. 9 is a flowchart of a stator and rotor winding internal fault diagnosis DSP (DIGITAL SIGNAL Processing) of an electrically excited synchronous motor according to one embodiment of the present application;

fig. 10 is an exemplary diagram of a stator-rotor winding internal fault diagnosis system of an electrically excited synchronous motor according to an embodiment of the present application;

Fig. 11 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present application and should not be construed as limiting the application.

The following describes a stator and rotor winding internal fault diagnosis method and device of an electrically excited synchronous motor according to an embodiment of the present application with reference to the accompanying drawings.

Specifically, fig. 1 is a schematic flow chart of a method for diagnosing internal faults of stator and rotor windings of an electro-excited synchronous motor according to an embodiment of the present application.

In this embodiment, the internal fault diagnosis method of the stator winding and the rotor winding of the electro-excitation synchronous motor can be implemented based on the internal fault diagnosis device of the stator winding and the rotor winding of the electro-excitation synchronous motor shown in fig. 2, as shown in fig. 2, the device can be aimed at a conditioning board of a small voltage signal, including four sub-circuit modules of acquisition, isolation, amplitude conversion and bias, and can perform real-time conditioning, isolation, sampling, analog/Digital (a/D) conversion and Digital signal operation on the acquired actual port voltage of the detection coil, so as to realize the detection function of the internal fault of the winding and solve the problem of real-time accurate monitoring of the small voltage signal; and the algorithm program can be used for diagnosing whether the stator internal short circuit fault or the rotor exciting winding turn-to-turn short circuit fault is on line, and outputting corresponding stator internal short circuit protection signals or exciting winding turn-to-turn short circuit alarm signals respectively.

Further, as shown in fig. 1, the method for diagnosing internal faults of stator and rotor windings of the electro-magnetic synchronous motor comprises the following steps:

In step S101, the actual port voltage of at least one detection coil is acquired.

The number of the detection coils can be 1 or more, and preferably, as shown in fig. 3, the number of the detection coils in the six-phase rectifying motor is 5.

It should be understood that the embodiment of the present application may collect the actual port voltage of the detection coil based on the stator-rotor winding internal fault diagnosis device of the electro-magnetic synchronous motor as shown in fig. 2.

In step S102, at least one fault signature is extracted from the actual port voltage of the at least one detection coil, and a protection sensitivity for the stator internal short circuit fault and a monitoring sensitivity for the rotor field winding inter-turn short circuit fault are calculated based on the at least one fault signature.

In some embodiments, the protection sensitivity calculation formula for the stator internal short circuit fault is as follows:

Wherein,

Wherein U _d,1 is the fundamental effective value in the actual port voltage, U _d,3 is the 3 rd harmonic effective value in the actual port voltage, U _d,5 is the 5 th harmonic effective value in the actual port voltage, and k is a natural number.

Wherein K _tol.1 is the reliable coefficient of the internal short-circuit protection of the stator, K _tol.1 is less than or equal to 2 and less than or equal to 10, n is the actual running rotating speed of the electric excitation synchronous motor, I _fd is the exciting current direct current component in the actual running of the electric excitation synchronous motor, n _normal is the rotating speed of the electric excitation synchronous motor in normal running, I _fd.normal is the exciting current of the electric excitation synchronous motor in normal running, U _d.normal,1 is the fundamental wave effective value of the actual port voltage of the electric excitation synchronous motor in normal running, U _d.normal,3 is the 3 rd harmonic effective value of the actual port voltage of the electric excitation synchronous motor in normal running, and U _d.normal,5 is the 5th harmonic effective value of the actual port voltage of the electric excitation synchronous motor in normal running.

In some embodiments, the calculation formula of the monitoring sensitivity of the rotor exciting winding turn-to-turn short circuit fault is as follows:

Wherein,

Wherein P is the pole pair number of the electro-excited synchronous motor, U _d,K/P is the effective value of K/P subharmonic in the actual port voltage, K is a natural number and is not an integer multiple of P.

Wherein K _tol.2 is the reliable coefficient of the turn-to-turn short circuit monitoring of the exciting winding, K _tol.2 is less than or equal to 2 and less than or equal to 10, n is the actual running speed of the electric exciting synchronous motor, I _fd is the exciting current direct current component in the actual running of the electric exciting synchronous motor, n _normal is the speed of the electric exciting synchronous motor in normal running, I _fd.normal is the exciting current of the electric exciting synchronous motor in normal running, and U _d.normal,K/P is the effective value of K/P harmonic of the actual port voltage of the electric exciting synchronous motor in normal running.

It should be appreciated that for stator winding short circuit faults, the characteristic components in the actual port voltage of the detection coil are the fundamental, 3 rd order, 5 th order, etc. odd order harmonics. The characteristic components caused by the turn-to-turn short circuit fault of the exciting winding in the actual port voltage of the detection coil are fractional harmonics of 1/P times (P is the pole pair number), 2/P times and the like. In the case of the six-phase commutated motor shown in fig. 3, since the motor is 2 pairs of poles, the characteristic components are 1/2, 3/2, 5/2, etc. equally divided harmonics. When designing the detection and diagnosis scheme, firstly, reasonably selecting the internal short circuit action quantity of the stator winding and the turn-to-turn short circuit monitoring quantity of the exciting winding: considering the magnitude of each subharmonic change before and after the fault, the stator winding internal short circuit action is taken as the total effective value of fundamental wave, 3 times and 5 times (see the formula (2) above, wherein k=2), and the excitation winding turn-to-turn short circuit monitoring is taken as the total effective value of 1/2, 3/2, 5/2, 7/2 and 9/2 subharmonics (see the formula (5) above, wherein k=1, 3,5,7 and 9).

The protection threshold value and the monitoring alarm value are set by considering the inherent voltage of the detection coil port during normal operation, preventing misoperation during normal operation of the motor, extracting the protection action quantity and the monitoring quantity from the detection coil port voltage during normal operation of the motor as reference values for setting, considering the influence of exciting current and rotating speed on the voltage, dividing the exciting current and rotating speed during actual operation by the exciting current and rotating speed during setting action value and alarm value, and multiplying the coefficient by the reference values and the reliability coefficients to serve as real-time protection threshold value and monitoring alarm value.

In step S103, the internal fault type of the stator winding and the rotor winding of the electrically excited synchronous motor is diagnosed according to the protection sensitivity and/or the monitoring sensitivity, wherein the internal fault type of the stator winding is the internal short-circuit fault of the stator when the protection sensitivity of the internal short-circuit fault of the stator is greater than or equal to a first preset threshold value, and the internal fault type of the stator winding is the inter-turn short-circuit fault of the exciting winding when the monitoring sensitivity of the inter-turn short-circuit fault of the rotor exciting winding is greater than or equal to a second preset threshold value.

The first preset threshold and the second preset threshold may be thresholds preset by a user, may be thresholds obtained through limited experiments, or may be thresholds obtained through limited computer simulation, and are not limited specifically herein. Preferably, the first preset threshold value k1∈ (1.2, 10) and the second preset threshold value k2∈ (1.2, 10).

It should be understood that, in the embodiment of the present application, an automatic setting program for the protection threshold value and the monitoring alarm value may be written based on the formulas (3) and (6), when the protection sensitivity of the stator internal short-circuit fault is greater than or equal to the first preset threshold value, the stator internal short-circuit fault type is the stator internal short-circuit fault, and when the monitoring sensitivity of the rotor exciting winding inter-turn short-circuit fault is greater than or equal to the second preset threshold value, the stator internal fault type is the exciting winding inter-turn short-circuit fault.

Further, in some embodiments, diagnosing a type of fault inside a stator winding and a rotor winding of an electrically excited synchronous motor according to a protection sensitivity and/or a monitoring sensitivity, further comprising: acquiring a first correction value of a protection threshold value of the internal short circuit of the stator and/or a second correction value of an alarm threshold value of the turn-to-turn short circuit of the rotor excitation winding; correcting a protection threshold value of the internal short circuit of the stator based on the first correction value, and correcting an alarm threshold value of the turn-to-turn short circuit of the exciting winding of the rotor based on the second correction value; and identifying the internal fault type of the stator and rotor windings of the electro-magnetic synchronous motor according to the corrected protection threshold value of the internal short circuit of the stator and/or the alarm threshold value of the turn-to-turn short circuit of the rotor exciting windings.

Wherein, in some embodiments, before obtaining the first correction value of the protection threshold value of the stator internal short circuit and/or the second correction value of the alarm threshold value of the rotor exciting winding turn-to-turn short circuit, the method further comprises: detecting and identifying whether the protection sensitivity of the stator internal short-circuit fault is greater than or equal to a third preset threshold value or whether the monitoring sensitivity of the rotor excitation winding inter-turn short-circuit fault is greater than or equal to a fourth preset threshold value after the protection sensitivity of the stator internal short-circuit fault is less than a first preset threshold value and the monitoring sensitivity of the rotor excitation winding inter-turn short-circuit fault is less than a second preset threshold value; if so, taking the action quantity of the internal short-circuit fault of the stator as a first correction value, and taking the monitoring quantity of the turn-to-turn short-circuit fault of the rotor exciting winding as a second correction value; the third preset threshold value is smaller than the first preset threshold value, and the fourth preset threshold value is smaller than the second preset threshold value.

In some embodiments, the calculation formula for correcting the protection threshold value of the internal short circuit of the stator based on the first correction value and correcting the alarm threshold value of the inter-turn short circuit of the exciting winding of the rotor based on the second correction value is as follows:

The third preset threshold and the fourth preset threshold may be thresholds preset by a user, may be thresholds obtained through limited experiments, or may be thresholds obtained through limited computer simulation, and are not limited specifically herein. Preferably, the third preset threshold value k3∈ (1, K1), and the fourth preset threshold value k4∈ (1, K2).

It should be appreciated that the above-described detection coil port voltage values should be zero during normal motor operation, and that when an internal winding short circuit fault occurs, fractional harmonic magnetic fields are generated in the air gap, which fields induce voltages in the detection coil. In theory, the motor winding can be considered to have an internal fault as long as the detection coil port voltage is detected to be not zero.

However, when the motor is actually operating normally, the detection coil with the special structure also has a port voltage with small amplitude (although the theoretical value is 0), and the inherent voltage is mainly caused by manufacturing process errors of the motor. In order to avoid misjudging as an internal short circuit fault of the stator or the rotor winding due to the inherent voltage of the detection coil port under the condition of normal operation of the motor and the like, reasonable (stator internal short circuit) protection threshold values and (rotor exciting winding inter-turn short circuit) monitoring alarm values are required to be set, for example, when no fault protection signal of the internal short circuit of the stator is output and no fault alarm signal of the exciting winding inter-turn short circuit is output, if the protection sensitivity is greater than or equal to a third preset threshold value or the monitoring sensitivity is greater than or equal to a fourth preset threshold value, the latest stator internal short circuit action quantity and rotor inter-turn short circuit monitoring quantity are used for replacing the fault threshold values, namely the corrected protection threshold values of the internal short circuit of the stator are shown in the formula (7), and the corrected alarm threshold values of the inter-turn short circuit of the exciting winding of the rotor are shown in the formula (8).

When the protection sensitivity of the internal short circuit fault of the stator is greater than or equal to a third preset threshold value and is smaller than a first preset threshold value, the action quantity of the internal short circuit fault of the stator is used as a first correction value to correct the action threshold value; and similarly, when the monitoring sensitivity is larger than or equal to a fourth preset threshold value and smaller than a second preset threshold value, the monitoring quantity of the turn-to-turn short circuit fault of the excited winding is used as a second correction value to correct the alarm threshold value.

Further, in some embodiments, the method for diagnosing internal faults of stator and rotor windings of an electrically excited synchronous motor further includes: and outputting a stator and rotor winding internal fault diagnosis result of the electro-magnetic synchronous motor.

It should be understood that, taking the six-phase commutated motor shown in fig. 3 as an example, 5 detection coils are installed in the six-phase commutated motor, in order to more intuitively display the fault diagnosis result, the embodiment of the present application designs a diagnosis result display LED (LIGHT EMITTING Diode) platelet, as shown in fig. 4. In the figure, the LED lamps 1 to 10 can respectively display the fault detection results of the detection coils 1 to 5. The LED lamps 1, 3, 5, 7 and 9 display the detection result of the internal short-circuit fault of the stator, and when a certain detection coil displays that the internal short-circuit fault of the stator occurs, the internal short-circuit fault lamp of the stator corresponding to the coil of the detection coil emits red light; 2. and the LED lamps 4, 6, 8 and 10 display the detection result of the turn-to-turn short circuit fault of the exciting winding, and when a certain detection coil displays that the turn-to-turn short circuit fault of the exciting winding occurs, the turn-to-turn short circuit fault lamp of the exciting winding corresponding to the coil is lighted (such as yellow light is emitted).

For example, a six-phase commutated motor used in accordance with an embodiment of the present application has a stator winding wiring diagram and a field winding wiring diagram as shown in fig. 5 and 6, respectively. The minimum degree of stator winding short circuit faults which can be realized on the motor are in-phase turn-to-turn short circuit and internal inter-phase short circuit of 12.5% of stator windings, such as b 21 to N1 short circuit or u 21 and w21 to N2 short circuit in fig. 5; the minimum possible turn-to-turn short circuit fault on the motor is 12.5% turn-to-turn short circuit of the field winding, such as tap 1 and tap 2 in fig. 6.

The effectiveness of the detection and diagnosis device according to the embodiment of the application takes the experimental results of the inter-turn short circuit of b 21 to N1 and the short circuit of the No. 1 tap and the No.2 tap of the excitation winding as examples. After the stator b 21 is short-circuited to the N1, the display result of the LED board is shown in fig. 7, wherein the detection coils of the No.2, the No. 3 and the No. 5 can accurately judge the turn-to-turn short circuit of the stator winding b 21 to the N1; when a short circuit between the No. 1 and No.2 taps inside the excitation winding occurs, namely, 12.5% turn-to-turn short circuit, the display result of the LED board is shown in FIG. 8, and the graph shows that the 5 detection coils can accurately judge the fault.

In order to facilitate those skilled in the art to further understand the internal fault diagnosis method for stator and rotor windings of the electro-magnetic synchronous motor according to the embodiment of the present application, the following description is further provided according to specific steps thereof, as shown in fig. 9:

S901, start.

S902, presetting an initial value of a fault threshold value and an alarm value.

S903, the sampling signal is read.

S904, the fault feature is read.

S905, calculating whether the parameter 1 is greater than or equal to K1, if so, executing S906, otherwise, executing S907.

The parameter 1 is protection sensitivity of the internal short circuit fault of the stator, and K1 is a first preset threshold. S906, outputting a fault protection signal of the internal short circuit of the stator.

S907, whether the parameter 2 is larger than or equal to K2 is calculated, if yes, S908 is executed, otherwise S909 is executed.

The parameter 2 is the monitoring sensitivity of the turn-to-turn short circuit fault of the rotor exciting winding, and K2 is a second preset threshold.

S908, outputting a fault alarm signal of the turn-to-turn short circuit of the exciting winding, and jumping to execute the step S903.

S909, judging whether the motor is normally operated, if so, executing S910, otherwise, executing S903.

S910, whether the calculation parameter 1 is greater than or equal to K3 or whether the calculation parameter 2 is greater than or equal to K4, if yes, S911 is executed, otherwise S903 is executed.

Wherein K3 is a third preset threshold, and K4 is a fourth preset threshold.

S911, correcting the protection threshold value of the internal short circuit of the stator based on the latest internal short circuit action quantity of the stator, correcting the alarm threshold value of the rotor exciting winding inter-turn short circuit based on the latest rotor inter-turn short circuit monitoring quantity, and simultaneously, continuously executing S903 until the internal fault diagnosis of the stator and the rotor windings is finished.

When the protection sensitivity of the internal short circuit fault of the stator is greater than or equal to a third preset threshold value and is smaller than a first preset threshold value, the action quantity of the internal short circuit fault of the stator is used as a first correction value to correct the action threshold value; and similarly, when the monitoring sensitivity is larger than or equal to a fourth preset threshold value and smaller than a second preset threshold value, the monitoring quantity of the turn-to-turn short circuit fault of the exciting winding is used as a second correction value to correct the alarm threshold value.

According to the stator and rotor winding internal fault diagnosis method of the electro-magnetic synchronous motor, the actual port voltage of at least one detection coil is collected, at least one fault feature is extracted from the actual port voltage, the protection sensitivity of the stator internal short-circuit fault and the monitoring sensitivity of the rotor exciting winding inter-turn short-circuit fault are calculated based on the feature, and therefore the stator and rotor winding internal fault type of the electro-magnetic synchronous motor is diagnosed, wherein if the protection sensitivity of the stator internal short-circuit fault is greater than or equal to a first preset threshold value, the internal fault type is the stator internal short-circuit fault, and if the monitoring sensitivity of the rotor exciting winding inter-turn short-circuit fault is greater than or equal to a second preset threshold value, the internal fault type is the exciting winding inter-turn short-circuit fault. Therefore, the problems that when internal faults of stator and rotor windings of the electrically excited synchronous motor are detected, the current transformers which are required to be installed are large in size and large in number, are difficult to be applied to limited spaces such as a movable energy platform, the maintenance workload is increased and the like are solved, the detection function of the internal faults of the stator and rotor windings is realized through an online detection device of the synchronous motor, the types of the faults are diagnosed online by utilizing an algorithm program, corresponding alarm signals are output in real time, and the sensitivity of fault detection is improved.

Next, a stator-rotor winding internal fault diagnosis system of an electro-magnetic synchronous motor according to an embodiment of the present application will be described with reference to the accompanying drawings.

Fig. 10 is a block schematic diagram of a stator-rotor winding internal fault diagnosis system of an electrically excited synchronous motor according to an embodiment of the present application.

As shown in fig. 10, the stator-rotor winding internal fault diagnosis system 10 of the electrically excited synchronous motor includes: an acquisition module 100, a calculation module 200, and a diagnostic module 300.

Wherein, the acquisition module 100 is used for acquiring the actual port voltage of at least one detection coil;

The calculation module 200 is configured to extract at least one fault feature from an actual port voltage of the at least one detection coil, and calculate a protection sensitivity of the stator internal short-circuit fault and a monitoring sensitivity of the rotor exciting winding inter-turn short-circuit fault based on the at least one fault feature;

The diagnostic module 300 is configured to diagnose a stator-rotor winding internal fault type of the electric excitation synchronous motor according to a protection sensitivity and/or a monitoring sensitivity, wherein the stator-rotor winding internal fault type is a stator internal short circuit fault when the protection sensitivity of the stator internal short circuit fault is greater than or equal to a first preset threshold, and the stator-rotor winding internal fault type is an excitation winding inter-turn short circuit fault when the monitoring sensitivity of the rotor excitation winding inter-turn short circuit fault is greater than or equal to a second preset threshold.

Further, in some embodiments, the protection sensitivity calculation formula for the stator internal short circuit fault is as follows:

Wherein, U _d,1 is the fundamental effective value in the actual port voltage, U _d,3 is the 3 rd harmonic effective value in the actual port voltage, U _d,5 is the 5 th harmonic effective value in the actual port voltage, k is a natural number,/>K _tol.1 is the reliable coefficient of the internal short-circuit protection of the stator, n is the actual running rotating speed of the electric excitation synchronous motor, I _fd is the exciting current direct current component in the actual running of the electric excitation synchronous motor, n _normal is the rotating speed of the electric excitation synchronous motor in the normal running, I _fd.normal is the exciting current of the electric excitation synchronous motor in the normal running, U _d.normal.1 is the fundamental wave effective value of the actual port voltage of the electric excitation synchronous motor in the normal running, U _d.normal.3 is the 3 rd harmonic effective value of the actual port voltage of the electric excitation synchronous motor in the normal running, and U _d.normal.5 is the 5 th harmonic effective value of the actual port voltage of the electric excitation synchronous motor in the normal running.

Further, in some embodiments, the monitoring sensitivity calculation formula for the rotor field winding turn-to-turn short circuit fault is as follows:

Wherein, P is the pole pair number of the electro-excited synchronous motor, U _d,K/P is the effective value of K/P subharmonic in the actual port voltage, K is a natural number and is not taken as an integer multiple of P,K _tol.2 is a reliable coefficient of the turn-to-turn short circuit monitoring of the exciting winding, n is the actual running rotating speed of the electric excitation synchronous motor, I _fd is an exciting current direct current component in the actual running of the electric excitation synchronous motor, n _normal is the rotating speed of the electric excitation synchronous motor in normal running, I _fd.normal is the exciting current of the electric excitation synchronous motor in normal running, and U _d.normal,K/P is the effective value of K/P harmonic of the actual port voltage of the electric excitation synchronous motor in normal running.

Further, in some embodiments, the diagnostic module is further to:

Detecting and identifying whether the protection sensitivity of the stator internal short-circuit fault is greater than or equal to a third preset threshold value or whether the monitoring sensitivity of the rotor excitation winding inter-turn short-circuit fault is greater than or equal to a fourth preset threshold value after the protection sensitivity of the stator internal short-circuit fault is less than a first preset threshold value and the monitoring sensitivity of the rotor excitation winding inter-turn short-circuit fault is less than a second preset threshold value;

If so, taking the action quantity of the internal short-circuit fault of the stator as a first correction value, and taking the monitoring quantity of the turn-to-turn short-circuit fault of the rotor exciting winding as a second correction value;

further, in some embodiments, the at least one fault signature comprises: odd harmonics and fractional harmonics.

According to the stator and rotor winding internal fault diagnosis system of the electric excitation synchronous motor, the actual port voltage of at least one detection coil is collected, at least one fault feature is extracted from the actual port voltage, the protection sensitivity of the stator internal short-circuit fault and the monitoring sensitivity of the rotor excitation winding inter-turn short-circuit fault are calculated based on the feature, so that the stator and rotor winding internal fault type of the electric excitation synchronous motor is diagnosed, wherein if the protection sensitivity of the stator internal short-circuit fault is greater than or equal to a first preset threshold value, the internal fault type is the stator internal short-circuit fault, and if the monitoring sensitivity of the rotor excitation winding inter-turn short-circuit fault is greater than or equal to a second preset threshold value, the internal fault type is the excitation winding inter-turn short-circuit fault. Therefore, the problems that when internal faults of stator and rotor windings of the electrically excited synchronous motor are detected, the current transformers which are required to be installed are large in size and large in number, are difficult to be applied to limited spaces such as a movable energy platform, the maintenance workload is increased and the like are solved, the detection function of the internal faults of the stator and rotor windings is realized through an online detection device of the synchronous motor, the types of the faults are diagnosed online by utilizing an algorithm program, corresponding alarm signals are output in real time, and the sensitivity of fault detection is improved.

Fig. 11 is a schematic structural diagram of an electronic device according to an embodiment of the present application. The electronic device may include:

Memory 1101, processor 1102, and a computer program stored on memory 1101 and executable on processor 1102.

The processor 1102 implements the stator-rotor winding internal fault diagnosis method of the electro-magnetic synchronous motor provided in the above embodiment when executing the program.

Further, the electronic device further includes:

a communication interface 1103 for communication between the memory 1101 and the processor 1102.

Memory 1101 for storing a computer program executable on processor 1102.

The memory 1101 may include a high-speed RAM memory or may further include a non-volatile memory (non-volatile memory), such as at least one magnetic disk memory.

If the memory 1101, the processor 1102, and the communication interface 1103 are implemented independently, the communication interface 1103, the memory 1101, and the processor 1102 may be connected to each other through a bus and perform communication with each other. The bus may be an industry standard architecture (Industry Standard Architecture, abbreviated ISA) bus, an external device interconnect (PERIPHERAL COMPONENT, abbreviated PCI) bus, or an extended industry standard architecture (Extended Industry Standard Architecture, abbreviated EISA) bus, among others. The buses may be divided into address buses, data buses, control buses, etc. For ease of illustration, only one thick line is shown in FIG. 11, but not only one bus or one type of bus.

Alternatively, in a specific implementation, if the memory 1101, the processor 1102, and the communication interface 1103 are integrated on a chip, the memory 1101, the processor 1102, and the communication interface 1103 may perform communication with each other through internal interfaces.

The processor 1102 may be a central processing unit (Central Processing Unit, CPU) or Application SPECIFIC INTEGRATED Circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present application.

The present embodiment also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the stator-rotor winding internal fault diagnosis method of the electrically excited synchronous motor as above.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or N embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, "N" means at least two, for example, two, three, etc., unless specifically defined otherwise.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and additional implementations are included within the scope of the preferred embodiment of the present application in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order from that shown or discussed, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the embodiments of the present application.

Logic and/or steps represented in the flowcharts or otherwise described herein, e.g., a ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or N wires, a portable computer cartridge (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium may even be paper or other suitable medium upon which the program is printed, as the program may be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.

It is to be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the N steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. As with the other embodiments, if implemented in hardware, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.

Those of ordinary skill in the art will appreciate that all or part of the steps carried out in the method of the above-described embodiments may be implemented by a program to instruct related hardware, and the program may be stored in a computer readable storage medium, where the program when executed includes one or a combination of the steps of the method embodiments.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing module, or each unit may exist alone physically, or two or more units may be integrated in one module. The integrated modules may be implemented in hardware or in software functional modules. The integrated modules may also be stored in a computer readable storage medium if implemented as software functional modules and sold or used as a stand-alone product.

The above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, or the like. While embodiments of the present application have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the application, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the application.

Claims

1. The method for diagnosing the internal faults of the stator winding and the rotor winding of the electrically excited synchronous motor is characterized in that at least one detection coil is arranged in the electrically excited synchronous motor, and the method comprises the following steps:

Acquiring an actual port voltage of the at least one detection coil;

Diagnosing the internal fault type of a stator winding and a rotor winding of the electric excitation synchronous motor according to the protection sensitivity and/or the monitoring sensitivity, wherein the internal fault type of the stator winding is a stator internal short-circuit fault when the protection sensitivity of the stator internal short-circuit fault is greater than or equal to a first preset threshold value, and the internal fault type of the stator winding is an excitation winding inter-turn short-circuit fault when the monitoring sensitivity of the rotor excitation winding inter-turn short-circuit fault is greater than or equal to a second preset threshold value;

The protection sensitivity calculation formula of the stator internal short circuit fault is as follows:

Wherein, U _d,1 is the fundamental effective value in the actual port voltage, U _d,3 is the 3 rd harmonic effective value in the actual port voltage, U _d,5 is the 5th harmonic effective value in the actual port voltage, k is a natural number,K _tol.1 is a reliable coefficient of stator internal short-circuit protection, n is an actual running rotating speed of the electric excitation synchronous motor, I _fd is an exciting current direct current component in the actual running of the electric excitation synchronous motor, n _normal is a rotating speed of the electric excitation synchronous motor in normal running, I _fd.normal is an exciting current of the electric excitation synchronous motor in normal running, U _d.normal,1 is a fundamental wave effective value of the actual port voltage of the electric excitation synchronous motor in normal running, U _d.normal,3 is a3 rd harmonic effective value of the actual port voltage of the electric excitation synchronous motor in normal running, and U _d.normal,5 is a 5 th harmonic effective value of the actual port voltage of the electric excitation synchronous motor in normal running;

the calculation formula of the monitoring sensitivity of the rotor exciting winding turn-to-turn short circuit fault is as follows:

Wherein, P is the pole pair number of the electro-excited synchronous motor, U _d,K/P is the effective value of K/P subharmonic in the actual port voltage, K is a natural number and is not an integer multiple of P,

K _tol.2 is the reliable coefficient of the excitation winding turn-to-turn short circuit monitoring, n is the actual running rotating speed of the electric excitation synchronous motor, I _fd is the exciting current direct current component in the actual running of the electric excitation synchronous motor, n _normal is the rotating speed of the electric excitation synchronous motor in the normal running, I _fd.normal is the exciting current of the electric excitation synchronous motor in the normal running, and U _d.normal,K/P is the effective value of the K/P harmonic of the actual port voltage in the normal running of the electric excitation synchronous motor.

2. The method according to claim 1, wherein said diagnosing the type of internal faults of stator and rotor windings of the electrically excited synchronous machine based on the protection sensitivity and/or the monitoring sensitivity, further comprises:

3. The method of claim 2, further comprising, prior to obtaining the first correction value of the protection threshold for the stator internal short and/or the second correction value of the alarm threshold for the rotor field winding inter-turn short:

4. A method according to claim 3, wherein the calculation formula for correcting the protection threshold value of the stator internal short circuit based on the first correction value and correcting the alarm threshold value of the rotor field winding turn-to-turn short circuit based on the second correction value is as follows:

5. The method of claim 4, wherein the at least one fault signature comprises: odd harmonics and fractional harmonics.

6. The method of any one of claims 1-5, further comprising:

7. An internal fault diagnosis system for stator and rotor windings of an electrically excited synchronous motor, characterized in that at least one detection coil is arranged in the electrically excited synchronous motor, wherein the system comprises:

The diagnosis module is used for diagnosing the internal fault type of the stator winding and the rotor winding of the electric excitation synchronous motor according to the protection sensitivity and/or the monitoring sensitivity, wherein the internal fault type of the stator winding is a stator internal short-circuit fault when the protection sensitivity of the stator internal short-circuit fault is greater than or equal to a first preset threshold value, and the internal fault type of the stator winding is an excitation winding inter-turn short-circuit fault when the monitoring sensitivity of the rotor excitation winding inter-turn short-circuit fault is greater than or equal to a second preset threshold value;

Wherein the at least one fault signature comprises: odd and fractional harmonics;

Wherein, U _d,1 is the fundamental effective value in the actual port voltage, U _d,3 is the 3 rd harmonic effective value in the actual port voltage, U _d,5 is the 5th harmonic effective value in the actual port voltage, k is a natural number,

K _tol.1 is a reliable coefficient of stator internal short-circuit protection, n is an actual running rotating speed of the electric excitation synchronous motor, I _fd is an exciting current direct current component in the actual running of the electric excitation synchronous motor, n _normal is a rotating speed of the electric excitation synchronous motor in normal running, I _fd.normal is an exciting current of the electric excitation synchronous motor in normal running, U _d.normal,1 is a fundamental wave effective value of the actual port voltage of the electric excitation synchronous motor in normal running, U _d.normal,3 is a3 rd harmonic effective value of the actual port voltage of the electric excitation synchronous motor in normal running, and U _d.normal,5 is a 5 th harmonic effective value of the actual port voltage of the electric excitation synchronous motor in normal running;

K _tol.2 is the reliable coefficient of the excitation winding turn-to-turn short circuit monitoring, n is the actual running rotating speed of the electric excitation synchronous motor, I _fd is the exciting current direct current component in the actual running of the electric excitation synchronous motor, n _normal is the rotating speed of the electric excitation synchronous motor in normal running, I _fd.normal is the exciting current of the electric excitation synchronous motor in normal running, and U _d.normal,K/P is the effective value of the K/P harmonic of the actual port voltage in normal running of the electric excitation synchronous motor.

8. The system of claim 7, wherein the diagnostic module is further configured to:

9. The system of any one of claims 7-8, further comprising:

10. An electronic device, comprising: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the stator-rotor winding internal fault diagnosis method of an electrically excited synchronous motor as claimed in any one of claims 1 to 6.

11. A computer-readable storage medium having stored thereon a computer program, characterized in that the program is executed by a processor for realizing the stator-rotor winding internal fault diagnosis method of an electrically excited synchronous motor as claimed in any one of claims 1 to 6.