CN114200376A - Fault pre-judging system for generator terminal voltage transformer and control method thereof - Google Patents
Fault pre-judging system for generator terminal voltage transformer and control method thereof Download PDFInfo
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- CN114200376A CN114200376A CN202111343396.6A CN202111343396A CN114200376A CN 114200376 A CN114200376 A CN 114200376A CN 202111343396 A CN202111343396 A CN 202111343396A CN 114200376 A CN114200376 A CN 114200376A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
- G01R35/02—Testing or calibrating of apparatus covered by the other groups of this subclass of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/56—Testing of electric apparatus
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Abstract
The invention discloses a fault pre-judging system for a generator-side voltage transformer and a control method thereof, wherein the fault pre-judging system comprises a detection device, a protection device and a controller, wherein the detection device is configured to obtain zero sequence voltage, and the zero sequence voltage is from a neutral point grounding transformer (PT) of a generator; the protection device is configured to protect the generator; the controller is internally provided with a first comparator circuit, a first input end of the first comparator is electrically connected with the detection device, a second input end of the first comparator is preset with a first voltage threshold, an output end of the first comparator is electrically connected with the protection device, when the zero sequence voltage is greater than the first voltage threshold, the controller controls the protection device to work through the first comparator circuit and sends first alarm information to the outside, and the first alarm information comprises PT early fault information. The technical scheme provided by the invention can be used for early warning the early faults of the PT.
Description
Technical Field
The invention relates to the field of power systems, in particular to a fault pre-judging system for a generator terminal voltage transformer and a control method thereof.
Background
A generator terminal voltage transformer (hereinafter referred to as "PT") is important electrical equipment in a large-scale thermal power plant, and usually three groups of generator terminal PTs are arranged, wherein one group adopts a fully insulated wiring mode and is used for inter-turn protection sampling of a generator and the like; and the neutral points of the PT primary windings in the two groups of semi-insulating wiring modes are directly grounded and are used for other purposes of protection, measurement, sampling and the like.
Due to the wide application of a shunt excitation generator type and a new energy power generation mode in recent years, the generator terminal voltage contains a large amount of higher harmonics, a generator neutral point grounding mode adopts an ineffective grounding mode, ferromagnetic resonance (especially a semi-insulating wiring mode PT fault occurs more) is easily caused under a special working condition, a power plant frequently generates a PT primary winding turn-to-turn short circuit fault, a generator terminal PT fuse is slowly fused, and further an unplanned shutdown accident is caused due to the PT fault.
The initial fault development of the primary winding turn-to-turn short circuit of the PT at the generator terminal is slow, a small amount of turn-to-turn short circuit exists in the primary winding, a fault point is far away from an iron core, the primary fuse of the PT is not completely disconnected, the fault characteristic is not obvious, and the fault characteristic is difficult to discover through means such as unbalanced current or temperature. Under the condition of losing fault monitoring means, when PT is developed into serious fault from early fault, because of small fault voltage sampling variation and sampling and logic dead zones of related protection and regulation devices, accident outage and unplanned unit outage accidents such as mistaken forced excitation, over-flux, overvoltage and mistaken tripping due to grounding protection of fundamental wave zero sequence stator of a generator are easily caused. Because no technology specially aiming at early fault diagnosis of the PT primary winding exists at home and abroad at the present stage, if a generator terminal PT primary winding turn-to-turn fault pre-judgment alarm scheme can be researched and invented, the early warning of the PT fault can be effectively realized, the fault point can be isolated in time, the unplanned shutdown can be avoided or reduced, the fault point can be quickly positioned and eliminated when equipment trips caused by the PT serious fault, the shutdown time of electric main equipment such as a generator and the like can be shortened, and the loss can be reduced.
The existing PT special protection technology generates primary element protection for reflecting the serious short circuit fault of a PT primary winding by utilizing primary safety inverse time limit action characteristics in China; PT disconnection protection for reflecting PT primary and secondary winding asymmetric faults by using an electric quantity negative sequence component or PT primary fuse slow-fusing protection in an excitation regulator; PT primary and secondary winding disconnection protection or PT primary fuse slow-fusing protection in an excitation regulator by using a dual-PT comparison line voltage deviation principle; PT disconnection protection devices and the like utilize line voltage of a generator, a phase current sampling threshold and line voltage sampling change rate sudden change fault quantity characteristics.
In the prior schemes, the principle of one-time insurance inverse time limit characteristic and the principle of electric quantity negative sequence component can reflect PT complete disconnection or internal serious faults, but the early slight faults of PT cannot be reflected in time, and the sensitivity is poor; the line voltage deviation principle of dual PT comparison is limited by a line voltage sampling dead zone of devices such as an excitation regulator and the like, so that early faults such as PT early slight faults and PT one-time fuse slow melting and the like cannot be reflected sensitively; the PT disconnection protection device utilizing the voltage and phase current sampling thresholds of the generator line is easy to malfunction when short-circuit faults, particularly unbalanced short-circuits, occur to the generator, a transformer bank and an adjacent power grid; the PT disconnection protection device utilizing the line voltage sampling change rate sudden change fault quantity characteristic is very easy to malfunction due to sudden change of sampling voltage when the external fault of a power grid, particularly large disturbance occurs. In summary, the conventional protection special for the turn-to-turn short circuit fault of the generator terminal voltage transformer has the disadvantages of incapability of carrying out early fault diagnosis, low sensitivity and easy misoperation, so that the protection has certain limitations.
Disclosure of Invention
The invention aims to provide a fault pre-judging system for a generator terminal voltage transformer and a control method thereof, which can judge and pre-warn the early fault of PT.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a fault pre-diagnostic system for a generator side voltage transformer, the fault pre-diagnostic system comprising:
a detection device configured to obtain a zero sequence voltage from a generator neutral point grounding to a single phase PT;
a protection device configured to protect the generator;
the controller is internally provided with a first comparator circuit, a first input end of the first comparator is electrically connected with the detection device, a second input end of the first comparator is preset with a first voltage threshold, an output end of the first comparator is electrically connected with the protection device, when the zero sequence voltage is greater than the first voltage threshold, the controller controls the protection device to work through the first comparator circuit and sends first alarm information to the outside, and the first alarm information comprises PT early fault information.
And a processing unit is arranged in the detection device and is configured to perform filtering processing on the zero sequence voltage, wherein the filtering processing mode comprises hardware filtering and/or Fourier algorithm filtering.
The controller is also internally provided with a first delayer which is configured with a first delay time, and the controller controls the protection device to work after the first delay time.
A second comparator circuit and a second time delay unit are further arranged in the controller, wherein a first input end of the second comparator is electrically connected with the detection device, a second input end of the second comparator is preset with a second voltage threshold, and an output end of the second comparator is electrically connected with the protection device; the second delayer is configured with a second delay time;
and when the zero sequence voltage is greater than the second voltage threshold value, after the second delay time, the controller controls the protection device to work through the second comparator circuit and sends second alarm information to the outside, wherein the second alarm information comprises stator grounding alarm information.
A third comparator circuit and a third time delay unit are further arranged in the controller, wherein a first input end of the third comparator is electrically connected with the detection device, a second input end of the third comparator is preset with a third voltage threshold, and an output end of the third comparator is electrically connected with the protection device; the third delayer is configured with a third delay time;
when the zero sequence voltage is greater than the third voltage threshold, after the third delay time, the controller controls the protection device to work through the third comparator circuit, and sends third alarm information to the outside, wherein the third alarm information comprises stator grounding trip information.
The first voltage threshold is 1V, the first delay time is 500ms, the second voltage threshold is 6V, the second delay time is 6.5s, the third voltage threshold is 20V, and the third delay time is 0.5 s.
The controller is internally provided with an AND gate logic circuit which is configured to control the protection device to work and send alarm information to the outside when the following conditions occur:
a. putting a stator grounding hard pressing plate; b. the stator grounding soft pressing plate is put into; PT one-time insurance slow melting putting-in and putting-out control word is '1'; d. the zero sequence voltage is greater than the first voltage threshold; e. the zero sequence voltage selection control word is '1'.
The fault prejudging system further comprises a prompting device which is configured to send alarm information, and the prompting device is a buzzer and/or an LED and/or a voice broadcast device.
A control method based on the above-described failure anticipation system, the control method comprising: the method comprises the steps of collecting zero sequence voltage of a generator, comparing the zero sequence voltage with a preset first voltage threshold, controlling a protection device of a fault pre-judging system to work when the zero sequence voltage is larger than the first voltage threshold, and sending first alarm information to the outside.
The control method further comprises the step of carrying out filtering processing on the zero sequence voltage, wherein the filtering processing mode comprises hardware filtering and/or Fourier algorithm filtering.
The invention has the advantages that: the method realizes sensitive judgment of the early fault of the PT, and provides possibility for isolating slightly faulty elements and reducing unplanned shutdown loss of the unit.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a first partial structure diagram of a fault pre-determination system according to an embodiment of the present invention;
fig. 2 is a first partial schematic block diagram of a fault pre-determination system according to an embodiment of the present invention;
fig. 3 is a second partial schematic block diagram of a fault pre-determination system according to an embodiment of the present invention.
Wherein the reference numerals include: 1-generator, 2-generator neutral point distribution transformer, 3-generator terminal PT protection I, and 4-generator terminal PT protection II.
Detailed Description
In order to make the technical solutions of the present invention better understood and more clearly understood by those skilled in the art, the technical solutions of the embodiments of the present invention will be described below in detail and completely with reference to the accompanying drawings. It should be noted that the implementations not shown or described in the drawings are in a form known to those of ordinary skill in the art. Additionally, while exemplifications of parameters including particular values may be provided herein, it is to be understood that the parameters need not be exactly equal to the respective values, but may be approximated to the respective values within acceptable error margins or design constraints. It is to be understood that the described embodiments are merely exemplary of a portion of the invention and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. In addition, the terms "comprises" and "comprising," and any variations thereof, in the description and claims of this invention, are intended to cover a non-exclusive inclusion, such that a process, method, apparatus, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The design idea of the invention is as follows: the method comprises the steps that a zero sequence voltage fault starting fixed value threshold in protection sampling is reduced, so that unbalanced short circuit and disconnection faults of other electric main equipment of a generator and a transformer set system are distinguished; the zero-sequence voltage of the neutral point of the generator is selected through the sampling point, and therefore the early stage of the turn-to-turn short circuit fault of a certain group of one phase of primary windings at the generator terminal PT is distinguished from the complete fusing (or the disconnection of a primary lead) of the primary fuse of the generator terminal PT and the open circuit (the tripping of a secondary single-phase small switch) of a secondary circuit; and the protection action exit mode is set as a delay alarm (no trip) and does not participate in other protection lockout logics, so that the protection action exit mode is different from other protection exit modes of the generator-transformer set system and PT disconnection protection.
In an embodiment of the present invention, a fault pre-determination system for a generator-side voltage transformer is provided, the fault pre-determination system includes a detection device, a protection device and a controller, wherein the detection device is configured to obtain a zero-sequence voltage, the zero-sequence voltage is from a neutral point ground to a single-phase PT of a generator, in addition, a processing unit is further disposed in the detection device, the processing unit is configured to perform filtering processing on the zero-sequence voltage to remove higher harmonics, the filtering processing manner includes hardware filtering and/or fourier algorithm filtering, in this embodiment, the zero-sequence voltage is filtered through hardware and fourier algorithm, and the protection range of the present invention is not limited thereby; the protection device is configured to protect the generator.
A first comparator circuit and a first time delay device are arranged in the controller, wherein a first input end of the first comparator is electrically connected with the detection device, a second input end of the first comparator is preset with a first voltage threshold, and an output end of the first comparator is electrically connected with the protection device; the first delayer is configured with a first delay time. Specifically, when the zero sequence voltage is greater than a first voltage threshold, after a first delay time, the controller controls the protection device to work through the first comparator circuit, and sends first alarm information to the outside, wherein the first alarm information comprises PT early failure information. In the present embodiment, the first voltage threshold is 1V, and the first delay time is 500ms, but the specific values are determined according to actual situations, and the protection scope of the present invention is not limited thereto.
In an embodiment of the present invention, a second comparator circuit and a second time delay unit are further disposed in the controller, wherein a first input terminal of the second comparator is electrically connected to the detection device, a second input terminal of the second comparator is preset with a second voltage threshold, and an output terminal of the second comparator is electrically connected to the protection device; the second delayer is configured with a second delay time;
when the zero sequence voltage is larger than the second voltage threshold value, after the second delay time, the controller controls the protection device to work through the second comparator circuit, and sends second alarm information to the outside, wherein the second alarm information comprises stator grounding alarm information. In this embodiment, the second voltage threshold is 6V, and the second delay time is 6.5s, but the specific values are determined according to actual situations, and the protection scope of the present invention is not limited thereto.
In an embodiment of the present invention, a third comparator circuit and a third time delay unit are further disposed in the controller, wherein a first input terminal of the third comparator is electrically connected to the detection device, a second input terminal of the third comparator is preset with a third voltage threshold, and an output terminal of the third comparator is electrically connected to the protection device; the third delayer is configured with a third delay time;
and when the zero sequence voltage is greater than a third voltage threshold value, after a third delay time, the controller controls the protection device to work through a third comparator circuit and sends third alarm information to the outside, wherein the third alarm information comprises stator grounding trip information. In this embodiment, the third voltage threshold is 20V, and the third delay time is 0.5s, but the specific values are determined according to actual situations, and the protection scope of the present invention is not limited thereto.
In one embodiment of the present invention, as shown in fig. 3, an and logic circuit is provided in the controller, and the and logic circuit is configured to control the protection device to operate and send the alarm information to the outside when the following conditions all occur: a. putting a stator grounding hard pressing plate; b. the stator grounding soft pressing plate is put into; PT one-time insurance slow melting putting-in and putting-out control word is '1'; d. the zero sequence voltage is greater than a first voltage threshold; e. the zero sequence voltage selection control word is '1'.
In an embodiment of the present invention, the present obstacle pre-judging system further includes a prompting device configured to send alarm information, and the prompting device is a buzzer and/or an LED and/or a voice announcer.
In one embodiment of the invention, the generator neutral point is grounded in an ineffective grounding mode or resistance, and the sampling of the zero-sequence voltage of the time base wave is generally taken from the neutral point side U when the generator neutral point is not effectively grounded0Terminal 3U0And comparing the two signals, and using the two signals as a sampling criterion for the generator stator grounding protection. Zero sequence voltage U passing through neutral point of generator0To identify turn-to-turn short circuit fault of generator terminal voltage transformer, zero sequence voltage U0The sampling is taken from the grounding of the neutral point of the generator to the single-phase PT, and the zero-sequence voltage sampling channel filters out higher harmonic components by adopting hardware filtering and software Fourier algorithm. The turn-to-turn short circuit fault of the generator-end voltage transformer can share a sampling channel with the generator fundamental wave zero sequence voltage stator grounding protection, the protection logics are similar, and the protection names, the fixed value starting thresholds and the outlet modes are different. The situation of one-time insurance slow melting caused by the voltage transformer of the generator sometimes happens, and is difficult to find, and the unplanned shutdown of the unit can be caused. Thus passing throughThe inter-turn short circuit fault pre-judging alarm logic of the generator terminal voltage transformer is added in the generator fundamental wave zero sequence voltage stator ground protection, early fault early warning can be well carried out, frequent misoperation of protection is considered to be prevented, the action value is not set to be too small, and optimization and adjustment can be carried out according to the actual working condition on site. According to the invention, the generator terminal voltage transformer turn-to-turn short circuit fault pre-judgment alarm and the generator fundamental wave zero sequence voltage stator ground protection are divided into three sections of fixed values at regular time so as to distinguish PT and different states of a stator in the operation process, wherein the three sections comprise a section I, a section II and a section III, wherein the section I is a pole sensitive section and represents the PT early fault; the section II is a sensitive section and represents stator grounding alarm; the section III is a non-sensitive section and represents the grounding tripping of the stator, and the action criterion is as follows:
U0＞U0j
U0＞U0l
U0＞U0f
in the formula of U0Is a neutral zero-sequence voltage of the generator, U0jRepresenting the turn-to-turn short-circuit protection constant value, U, of the extremely sensitive segment0lRepresenting the sensitive turn-to-turn short-circuit protection constant, U0fRepresenting the insensitive turn-to-turn short circuit protection constant value.
In an embodiment of the present invention, as shown in fig. 1, the present fault pre-judging system includes a generator 1, a generator neutral point distribution transformer 2, a generator terminal PT protection-3 and a generator terminal PT protection-two 4, specifically, a generator terminal voltage transformer is protected by using a generator terminal PT protection-3 and a generator terminal PT protection-two 4 turn-to-turn short circuit fault dedicated protection pre-judging alarm, respectively, and sampling is performed by using a sampling channel shared with a generator fundamental wave zero sequence voltage stator ground protection, wherein, as shown in fig. 1, zero sequence voltages generated by the generator neutral point distribution transformer 2 correspond to the generator terminal PT protection-3 and the generator terminal PT protection-two 4, respectively, and then the neutral point U in a protection a cabinet and a protection B cabinet shown in fig. 2 is removed respectively0Thereby participating in the logic calculations in the controller as shown in fig. 3. In this embodiment, the model of the microcomputer protection device is WFB-801A, and the model is established in the deviceWith the following logic, as shown in fig. 2, when the platen is turned on and the control word is "1", and the zero sequence voltage reaches the protection start threshold, the apparatus will send out a one-time safety slow-fusing alarm at the terminal PT. The set value of the pole sensitive section for the pre-judging alarm of the turn-to-turn short circuit fault of the generator voltage transformer in the embodiment is set to be 1V, the alarm is delayed for 500ms, but when the set value of the pole sensitive section is applied to other units, the change rule of the sampling parameter may be changed due to different units or actual working conditions. The other two sections are the existing generator stator ground protection, and can be matched with the PT early fault, so that the early warning and protection of the generator PT and the stator fault in the whole period are realized. And the II section and the III section maintain the original protection constant values unchanged, the constant value of the sensitive section of the II section is 6V, the time delay is 6.5S trip, the constant value of the insensitive section of the III section is 20V, and the time delay is 0.5S trip. The setting of the fixed value of the extremely sensitive section strives for precious time for early warning of early faults of a generator terminal PT and preventing the unit from non-stop caused by accident enlargement.
In an embodiment of the present invention, there is provided a control method based on the above-described failure prediction system, the control method including: the method comprises the steps of collecting zero sequence voltage of a generator, comparing the zero sequence voltage with a preset first voltage threshold, controlling a protection device of a fault pre-judging system to work when the zero sequence voltage is larger than the first voltage threshold, and sending first alarm information to the outside.
Furthermore, the control method further comprises the step of carrying out filtering processing on the zero sequence voltage, wherein the filtering processing mode comprises hardware filtering and/or Fourier algorithm filtering.
The idea of the embodiment of the control method is the same as the working process of the fault pre-determination system in the embodiment, and the entire content of the embodiment of the fault pre-determination system is incorporated into the embodiment of the control method by full-text reference, which is not described again.
The invention aims to solve the technical problem that the prior art cannot identify the early turn-to-turn short circuit fault of the PT at the generator terminal, so that the accident range is enlarged. The method is sensitive to the early fault reflection of the PT, and provides possibility for isolating slightly faulty elements and reducing the unplanned outage loss of the unit; the design is simple, the zero sequence voltage sampling of the stator grounding protection in the existing generator-transformer unit microcomputer protection is used, the hardware investment is not required to be increased, and the cost is greatly reduced; meanwhile, only a pair of alarm contacts needs to be added to the spare outlet channel, so that wiring work is less, and engineering cost is saved; in addition, the use criterion is simple, the excitation regulator, the fault recorder and the like in the system are easy to realize function fusion and complementation, and the accurate positioning of the fault is facilitated.
The above description is only for the preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes that can be directly or indirectly applied to other related technical fields using the contents of the present specification and the accompanying drawings are included in the scope of the present invention.
Claims (10)
1. A fault pre-determination system for a generator-side voltage transformer, the fault pre-determination system comprising:
a detection device configured to obtain a zero sequence voltage from a generator neutral point grounding to a single phase PT;
a protection device configured to protect the generator;
the controller is internally provided with a first comparator circuit, a first input end of the first comparator is electrically connected with the detection device, a second input end of the first comparator is preset with a first voltage threshold, an output end of the first comparator is electrically connected with the protection device, when the zero sequence voltage is greater than the first voltage threshold, the controller controls the protection device to work through the first comparator circuit and sends first alarm information to the outside, and the first alarm information comprises PT early fault information.
2. The fault pre-judging system according to claim 1, wherein a processing unit is provided in the detecting device, and the processing unit is configured to perform filtering processing on the zero sequence voltage, and the filtering processing includes hardware filtering and/or fourier algorithm filtering.
3. The fault pre-judging system according to claim 1, wherein a first delay timer is further provided in the controller and configured with a first delay time, and the controller controls the protection device to operate after the first delay time.
4. The fault pre-judging system according to claim 3, wherein a second comparator circuit and a second time delay unit are further disposed in the controller, wherein a first input terminal of the second comparator is electrically connected to the detecting device, a second input terminal of the second comparator is preset with a second voltage threshold, and an output terminal of the second comparator is electrically connected to the protecting device; the second delayer is configured with a second delay time;
and when the zero sequence voltage is greater than the second voltage threshold value, after the second delay time, the controller controls the protection device to work through the second comparator circuit and sends second alarm information to the outside, wherein the second alarm information comprises stator grounding alarm information.
5. The fault pre-judging system according to claim 4, wherein a third comparator circuit and a third time delay unit are further disposed in the controller, wherein a first input terminal of the third comparator is electrically connected to the detecting device, a second input terminal of the third comparator is preset with a third voltage threshold, and an output terminal of the third comparator is electrically connected to the protecting device; the third delayer is configured with a third delay time;
when the zero sequence voltage is greater than the third voltage threshold, after the third delay time, the controller controls the protection device to work through the third comparator circuit, and sends third alarm information to the outside, wherein the third alarm information comprises stator grounding trip information.
6. The fault pre-determination system according to claim 5, wherein the first voltage threshold is 1V, the first delay time is 500ms, the second voltage threshold is 6V, the second delay time is 6.5s, the third voltage threshold is 20V, and the third delay time is 0.5 s.
7. The fault pre-judging system according to claim 1, wherein an and gate logic circuit is arranged in the controller, and the and gate logic circuit is configured to control the protection device to operate and send alarm information to the outside when the following conditions all occur:
a. putting a stator grounding hard pressing plate;
b. the stator grounding soft pressing plate is put into;
PT one-time insurance slow melting putting-in and putting-out control word is '1';
d. the zero sequence voltage is greater than the first voltage threshold;
e. the zero sequence voltage selection control word is '1'.
8. The failure prejudgment system according to claim 1, further comprising a prompting device configured to send alarm information, wherein the prompting device is a buzzer and/or an LED and/or a voice announcer.
9. A control method based on the failure prediction system according to claim 1, characterized by comprising: the method comprises the steps of collecting zero sequence voltage of a generator, comparing the zero sequence voltage with a preset first voltage threshold, controlling a protection device of a fault pre-judging system to work when the zero sequence voltage is larger than the first voltage threshold, and sending first alarm information to the outside.
10. The control method according to claim 9, further comprising performing a filtering process on the zero sequence voltage, wherein the filtering process includes a hardware filtering and/or a fourier algorithm filtering.
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| CN202111343396.6A CN114200376A (en) | 2021-11-13 | 2021-11-13 | Fault pre-judging system for generator terminal voltage transformer and control method thereof |
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| CN202111343396.6A CN114200376A (en) | 2021-11-13 | 2021-11-13 | Fault pre-judging system for generator terminal voltage transformer and control method thereof |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117269700A (en) * | 2023-11-20 | 2023-12-22 | 国网江西省电力有限公司电力科学研究院 | Voltage transformer insulation defect diagnosis method based on fault wave recording information |
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2021
- 2021-11-13 CN CN202111343396.6A patent/CN114200376A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117269700A (en) * | 2023-11-20 | 2023-12-22 | 国网江西省电力有限公司电力科学研究院 | Voltage transformer insulation defect diagnosis method based on fault wave recording information |
| CN117269700B (en) * | 2023-11-20 | 2024-03-12 | 国网江西省电力有限公司电力科学研究院 | Voltage transformer insulation defect diagnosis method based on fault wave recording information |
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