CN116298883A - Accurate testing method and device for hydraulic generator ground fault current - Google Patents
Accurate testing method and device for hydraulic generator ground fault current Download PDFInfo
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- 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
- G01R31/52—Testing for short-circuits, leakage current or ground faults
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
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- Y04S10/52—Outage or fault management, e.g. fault detection or location
Abstract
The application provides a method and a device for accurately testing the ground fault current of a hydraulic generator, and belongs to the technical field of hydraulic generator operation and maintenance. The method comprises the following steps: acquiring a grounding current signal of a neutral point of the hydraulic generator and a capacitance current value of a single camera end corresponding to the grounding fault point of the hydraulic generator; aiming at the grounding current signal, calculating an effective grounding current value of a neutral point of the hydraulic generator by adopting a Fourier series transformation method and a frequency domain fast algorithm; and calculating the grounding current value of the hydraulic generator fault point based on the effective grounding current value of the hydraulic generator neutral point and the capacitance current value of the corresponding single camera end at the hydraulic generator grounding fault point. According to the method, when the hydraulic generator has single-phase grounding faults, the neutral point grounding current can be accurately measured, and the grounding current value of the hydraulic generator fault point can be calculated.
Description
Technical Field
The application relates to the technical field of hydraulic generator operation and maintenance, in particular to a hydraulic generator ground fault current accurate test method and device.
Background
The large hydropower station is responsible for the main body of energy supply and guarantee, particularly the hydropower installation capacity in a certain area is close to 80%, and when the extreme conditions of high temperature, drought and power load superposition occur, the problem of insufficient large-area energy supply can occur. Under the extreme condition, the reliable operation level of the equipment body needs to be improved as much as possible, so that the hydroelectric generating set is prevented from being failed as much as possible, and the contradiction between energy supply and demand is aggravated. Meanwhile, a fault emergency plan is needed to be made, core equipment of a non-redundant design of the focusing hydroelectric generating set is ensured, damage caused by damage to the core equipment is avoided, the overrun operation capability of the equipment is fully developed, fault crossing of the core component to accidents is realized, and reliable energy supply under extreme conditions is ensured to the maximum extent.
The prior generator protection system does not have a sensor for accurately monitoring the ground fault current, and when a single-phase ground fault occurs in a generator, the neutral point voltage is raised from 0V to the phase voltageU d Testing the neutral point voltage of the generatorU 0 . Because the current hydraulic generator does not have a device for accurately monitoring the fault grounding current, once the grounding fault occurs, the hydraulic generator can be stopped.
The main risk of the grounding fault to the generator is the risk of over-current burning of the iron core, the grounding fault current distortion is serious, the traditional method directly tests through a clamp ammeter, the tested current value is an instantaneous value, and the damage of the grounding current to the stator iron core cannot be accurately reflected.
Disclosure of Invention
The embodiment of the application aims to provide a method and a device for accurately testing the ground fault current of a hydraulic generator. According to the method, when the hydraulic generator has single-phase grounding faults, the neutral point grounding current can be accurately measured, and the grounding current value of the hydraulic generator fault point can be calculated.
In order to achieve the above object, a first aspect of the present application provides a method for accurately testing a ground fault current of a hydraulic generator, the method comprising:
acquiring a grounding current signal of a neutral point of the hydraulic generator and a capacitance current value of a single camera end corresponding to the grounding fault point of the hydraulic generator;
aiming at the grounding current signal, calculating an effective grounding current value of a neutral point of the hydraulic generator by adopting a Fourier series transformation method and a frequency domain fast algorithm;
and calculating the grounding current value of the hydraulic generator fault point based on the effective grounding current value of the hydraulic generator neutral point and the capacitance current value of the corresponding single camera end at the hydraulic generator grounding fault point.
In an embodiment of the present application, the ground current signal is a ground current digital signal, and the method further includes:
acquiring a grounding current acquisition signal of a neutral point of the hydraulic generator, and performing filtering processing on the grounding current acquisition signal through a signal conditioning circuit to acquire a grounding current analog signal;
and performing analog-to-digital conversion processing on the grounding current analog signal to obtain a grounding current digital signal.
In this embodiment of the present application, for the ground current signal, an effective ground current value of a neutral point of a hydraulic generator is calculated by using a fourier transform method and a frequency domain fast algorithm, including:
the grounding current signals are subjected to sequence division based on a preset number of power frequency periodic waves to obtain a basic calculation sequencet(n)；
Computing basic computation sequences using fourier transform methodst(n) Frequency components of (2)
；
Using Pasteur formula to calculate the frequency component
And calculating an effective grounding current value of the neutral point of the hydraulic generator.
In an embodiment of the present application, the method further includes: calculating a basic calculation sequence according to formula (15)t(n) Is of the synchronization time of (a)t syn (n)：
In the method, in the process of the invention,t syn (n) Represent the first
Basic calculation sequencet(n) Is a synchronous time of (1); 0.2 represents the time window length of the basic calculation sequence; />
Representing the sequence number of the basic calculation sequence.
In the embodiment of the application, a Fourier transform method is adopted to calculate a basic calculation sequencet(n) Frequency components of (2)
Comprising:
calculating a basic calculation sequence according to formulas (16) - (18)t(n) Frequency components of (2)
：
In the method, in the process of the invention,
and->
Representing a fourier series; />
Representing the frequency components; />
Representing the spectral line.
In the embodiment of the application, the basic calculation sequence is calculated according to the formula (21)t(n)：
In the method, in the process of the invention,
representing the frequency components; />
Representing spectral lines; />
Representing discrete frequency points; />
Is the power frequency angular frequency, wherein
；/>
For spectral lines->
Is a phase angle of (c).
In the embodiment of the application, the Pasteur formula is adopted to calculate the frequency component
Calculating an effective ground current value for a hydro-generator neutral point, comprising:
calculating the effective ground current value of the neutral point of the hydro-generator according to formulas (23) and (25):
in the method, in the process of the invention,
representation->
The effective grounding current value of the neutral point of the hydraulic generator at the moment; />
Representing the frequency components;I 0 (t) Representation oftAnd the effective grounding current value of the neutral point of the hydraulic generator at the moment.
In this embodiment of the present application, based on the effective ground current value of the hydraulic generator neutral point and the capacitance current value of the single camera end corresponding to the hydraulic generator ground fault point, the calculating the ground current value of the hydraulic generator fault point includes:
according to the formula (26), calculating the grounding current value of the fault point of the hydraulic generator:
in the method, in the process of the invention,
a ground current value representing a hydraulic generator fault point; k represents a proportionality coefficient;I Ctest representing a capacitance current value of a corresponding single camera end at a hydraulic generator ground fault point; />
Representation->
And the effective grounding current value of the neutral point of the hydraulic generator at the moment.
The second aspect of the present application provides a hydraulic generator ground fault current accurate test device, the device includes:
the acquisition module is used for acquiring a grounding current signal of a neutral point of the hydraulic generator and a capacitance current value of a corresponding single camera end at a grounding fault point of the hydraulic generator;
the first calculation module is used for calculating the effective grounding current value of the neutral point of the hydraulic generator by adopting a Fourier series transformation method and a frequency domain fast algorithm aiming at the grounding current signal;
and the second calculation module is used for calculating the grounding current value of the hydraulic generator fault point based on the effective grounding current value of the hydraulic generator neutral point and the capacitance current value of the corresponding single camera end at the hydraulic generator grounding fault point.
A third aspect of the present application provides a processor configured to perform the above-described hydraulic generator ground fault current accuracy testing method.
A fourth aspect of the present application provides a machine-readable storage medium having stored thereon instructions that, when executed by a processor, cause the processor to be configured to perform the hydro-generator ground fault current accuracy test method described above.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
the application provides an accurate test method and device for the grounding fault current of a hydraulic generator, wherein when a single-phase grounding fault occurs to the hydraulic generator, the method can accurately measure the neutral point grounding current and calculate the grounding current value of the fault point of the hydraulic generator, so that the damage of the grounding current to a stator core is effectively reflected.
Additional features and advantages of embodiments of the present application will be set forth in the detailed description that follows.
Drawings
The accompanying drawings are included to provide a further understanding of embodiments of the present application and are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and together with the description serve to explain, without limitation, the embodiments of the present application. In the drawings:
FIG. 1 schematically illustrates a schematic ground fault ride-through of a hydro-generator according to an embodiment of the application;
FIG. 2 schematically illustrates a flow chart of a hydro-generator ground fault current accuracy test method according to an embodiment of the present application;
fig. 3 schematically illustrates a signal conditioning circuit diagram according to an embodiment of the present application;
FIG. 4 schematically illustrates a dynamic zero crossing schematic of a synchronization module according to an embodiment of the present application;
FIG. 5 schematically illustrates a ground current digitizing schematic of a sampling module according to an embodiment of the present application;
FIG. 6 schematically illustrates an overall block diagram of a hydro-generator ground fault current accuracy testing device according to an embodiment of the application;
fig. 7 schematically shows a block diagram of a hydraulic generator ground fault current accuracy testing device according to an embodiment of the present application.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it should be understood that the specific implementations described herein are only for illustrating and explaining the embodiments of the present application, and are not intended to limit the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.
It should be noted that, if there is a description of "first", "second", etc. in the embodiments of the present application, the description of "first", "second", etc. is only for descriptive purposes, and is not to be construed as indicating or implying 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 addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be regarded as not exist and not within the protection scope of the present application.
Fig. 1 schematically illustrates a ground fault ride-through schematic of a hydro-generator according to an embodiment of the application. As shown in FIG. 1, in the figureI K Is a ground fault current,E A Is the phase A potential of the generator,E B Is the phase B potential of the generator,E C Is the camera potential of the generator C,U A Is the voltage of the generator A phase terminal,U B Is an electric generatorBCamera terminal voltage,U C Is the voltage of the camera end of the generator C,I a Is the phase A capacitance current of the generator,I b Is the B-phase capacitance current of the generator,I c Is the C-phase capacitance current of the generator,U 0 is the neutral point voltage of the generator,I 0 Is the neutral point grounding current of the generator,U N Is the rated line voltage of the generator,RIs a neutral point grounding resistor of a generator,XThe neutral point of the generator is grounded.
The single-phase grounding fault of the hydro-generator accounts for more than 80% of the stator faults, and the embodiment takes the single-phase grounding fault at the camera end of the hydro-generator C in FIG. 1 as an example, and ignores the influence of grounding resistance and internal winding impedance.
Phase voltage of generatorU d The method comprises the following steps:
line voltage of generatorU N The method comprises the following steps:
after the generator C phase generator end of the machine fails:
generator C grounding currentI K Calculated according to kirchhoff's current law:
I C the capacitive current belongs to basic parameters of the generator and can be obtained through tests.I 0 The neutral point grounding current is obtained in real time through the fault ride-through device.
From the above, after single-phase earth fault occurs, the terminal voltage of the generator C cameraU C Reduced to 0V, neutral point voltageU 0 Rise to phase voltage, generator A phase terminal voltageU A And generator B camera terminal voltageU B Rise to line voltageU N . The non-faulted A, B phase voltage increases by a factor of 1.73.
The ground fault current distortion is serious, and the traditional method directly tests through a clamp ammeter, so that the tested current value is an instantaneous value and cannot accurately reflect the damage of the ground current to the stator core. According to the method, the damage mechanism of the stator core of the generator is a thermal effect when the ground fault occurs, the influence of the ground current is monitored in real time from the thermal effect, the generator is not damaged when the ground fault occurs, and the ground fault ride-through is realized.
In one embodiment, the method comprises: acquiring a grounding current acquisition signal of a neutral point of the hydraulic generator, and performing filtering processing on the grounding current acquisition signal through a signal conditioning circuit to acquire a grounding current analog signal; and performing analog-to-digital conversion processing on the grounding current analog signal to obtain a grounding current digital signal.
In this embodiment, the current transformer may be used to obtain a signal of the ground current of the neutral point of the hydraulic generatori 0 (t). The ground current signal can be processed by a signal conditioning circuiti 0 (t) Filtering to obtain ground current analog signali 1 (t). The signal conditioning circuit is used for filtering high-frequency interference. Fig. 3 schematically illustrates a signal conditioning circuit diagram according to an embodiment of the present application, as shown in fig. 3, the signal conditioning circuit includes: the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the first capacitor C1, the second capacitor C2 and the operational amplifier.
The first resistor R1 and the second resistor R2 are connected in series, and one end of the second resistor R2 far away from the first resistor R1 is connected with the same-direction input end of the operational amplifier. One end of the first capacitor C1 is connected with the same-direction input end of the operational amplifier, and the other end of the first capacitor C is grounded. One end of the second capacitor C2 is connected between the first resistor R1 and the second resistor R2, and the other end of the second capacitor C is connected with the output end of the operational amplifier. One end of the third resistor R3 is connected with the reverse input end of the operational amplifier, and the other end of the third resistor R is grounded. One end of the fourth resistor R4 is connected with the reverse input end of the operational amplifier, and the other end of the fourth resistor R4 is connected with the output end of the operational amplifier.
In this embodiment, the filtering design needs to be performed on the frequency domain in the signal conditioning circuit:
in the method, in the process of the invention,srepresenting the variation of the frequency domain,H(s) As a transfer function of the signal conditioning circuit,V 1 (s) For the frequency domain input of the signal conditioning circuit,V 2 (s) For the frequency domain output of the signal conditioning circuit, K represents the gain factor of the transfer function,aandbrespectively represent the adjustment coefficients of the transfer function, K,aAndball as signal conditioning circuit design parameters shown in fig. 3.
Design parameter K of signal conditioning circuit,aAndbthe design relationship with the circuit elements in fig. 3 is as follows:
the transfer function value at zero point is the gain coefficientG：
Cut-off frequency of signal conditioning circuitf c = w c 2 pi is set to 0.707G:
determining gain factor G and cut-off frequency of signal conditioning circuit according to design requirementf c The component parameters in the circuit of fig. 3 were then designed according to the following relationship:
in the middle ofR 1 、R 2 、R 3 、R 4 The resistance values in the signal conditioning circuit of figure 3,C 1 、C 2 the capacitance values in the signal conditioning circuit of fig. 3, respectively.
In this embodiment, the sampling module is used for sampling the ground current analog signali 1 (t) Analog-to-digital conversion processing is carried out to obtain a grounding current digital signali 1 (n). FIG. 5 schematically illustrates grounding of a sampling module according to an embodiment of the present applicationAs shown in fig. 5, the sampling module samples the conditioned ground current analog signali 1 (t) Discrete into digital signals at a frequency of 10kHzi 1 (n)。
Fig. 2 schematically shows a flow chart of a hydraulic generator ground fault current accuracy test method according to an embodiment of the present application. As shown in fig. 2, in an embodiment of the present application, a method for accurately testing a ground fault current of a hydraulic generator is provided, and this embodiment is mainly exemplified by the method applied to the fault ride through monitoring device in fig. 1, and includes the following steps:
step 110, obtaining a grounding current signal of a neutral point of the hydraulic generator and a capacitance current value of a corresponding single camera end at the grounding fault point of the hydraulic generator.
In this embodiment, the ground current signal is a ground current digital signal. The capacitance current value of the corresponding single camera end at the grounding fault point of the hydraulic generator can be obtained through real machine test.
And 120, calculating the effective grounding current value of the neutral point of the hydraulic generator by adopting a Fourier series transformation method and a frequency domain fast algorithm aiming at the grounding current signal.
In this embodiment, ten power frequency periodic waves are used as a basic calculation sequence, the sampling rate is set to 10kHz, the number of sample points of a single power frequency periodic wave is 200, and the length of the basic calculation sequence is 2000. The initial dynamic zero crossing point isi tr (1) Then (1)nThe individual basic calculation sequences are expressed ast(n)：
As shown in FIG. 4, with initial dynamic zero crossingi tr (1) As zero time, the firstnThe basic calculation sequence is clocked by the 1 st sample point, and the synchronization time is as follows:
nth basic calculation sequencet(n) The synchronization time ist syn (n) Calculating a Fourier series:
where k represents the kth frequency domain spectral line, and the corresponding frequency is:
the time window length t=0.2 s of the basic calculation sequence, frequency interval ΔfIs that
Time domain off-line signalt(n) Can be represented by 250 frequency domain spectral lines
In the method, in the process of the invention,
and->
Representing a fourier series; />
Representing the frequency components; />
Representing spectral lines; />
Representing discrete frequency points; />
Is the power frequency angular frequency, wherein->
；/>
For spectral lines->
Is a phase angle of (c).
According to the embodiment, according to the fact that the time domain waveform energy in the Pasteur equation is equal to the frequency domain energy, the frequency domain calculation method is adopted, so that the calculation efficiency is greatly improved, and the energy value of the neutral point grounding current is accurately measured with extremely low hardware cost. The time domain function of the neutral point grounding current is thatI 0 (t) The energy of the current is the time domain integral of the square of the current, since time domain processing methods are detrimental to digital signal processing, converting the time domain energy to frequency domain calculations according to the pasival equation:
the sampling rate in this embodiment is set to 10kHz, the sampling time window is set to t=0.2 s, the frequency interval ΔfFor 5Hz, only 25 times harmonic frequency domain calculation is considered, and the discrete frequency points are calculated as follows:
thus, it can be calculatedt syn (n) At the moment, the effective value of the neutral point grounding current:
in the method, in the process of the invention,
representation->
The effective grounding current value of the neutral point of the hydraulic generator at the moment; />
Representing the frequency components; i 0 And (t) represents an effective ground current value of the neutral point of the hydraulic generator at the time t.
And 130, calculating the grounding current value of the hydraulic generator fault point based on the effective grounding current value of the hydraulic generator neutral point and the capacitance current value of the corresponding single camera end at the hydraulic generator grounding fault point.
In this embodiment, according to formula (6), the ground current is the vector sum of the capacitance current and the neutral point current, and the capacitance current is tested by a real machine as followsI Ctest Setting a proportionality coefficientKThe fault point grounding current can be obtained:
in the method, in the process of the invention,
representing the fault point grounding current value of the hydraulic generator; k represents a proportionality coefficient;I Ctest representing a capacitance current value of a corresponding single camera end at a hydraulic generator ground fault point; />
Representation->
And the effective grounding current value of the neutral point of the hydraulic generator at the moment.
In one embodiment, the ground current value at the point of failure of the hydro-generator
When the current value is smaller than a first set current value, the water generator-generator operates according to a first preset time; ground current value +.>
When the current value is larger than or equal to the first set current value and smaller than the second set current value, the hydro-generator operates according to the second preset time; ground current value +.>
When the current value is larger than or equal to the second set current value, the hydro-generator is stopped immediately.
For example, fault early warning can be performed in three cases according to the magnitude of the fault point ground current, as shown in formula (27). It should be noted that the given values are representative, but the early warning values should be set according to the specific generator.
In this embodiment, the generator may be operated for 1-2 hours when the fault point ground current is less than 4A; when the fault point ground current is greater than or equal to 4A and less than 10A, the generator may be operated for a short period of time, for example, 10-15 minutes; when the fault point grounding current is greater than or equal to 10A, the generator is immediately stopped. FIG. 2 is a flow chart of a method for accurately testing the ground fault current of a hydro-generator according to one embodiment. It should be understood that, although the steps in the flowchart of fig. 2 are shown in sequence as indicated by the arrows, the steps are not necessarily performed in sequence as indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in fig. 2 may include multiple sub-steps or stages that are not necessarily performed at the same time, but may be performed at different times, nor do the order in which the sub-steps or stages are performed necessarily performed in sequence, but may be performed alternately or alternately with at least a portion of the sub-steps or stages of other steps or other steps.
In one embodiment, as shown in fig. 7, there is provided an accurate testing device for a ground fault current of a hydraulic generator, including an acquisition module 210, a first calculation module 220, and a second calculation module 230, where:
the acquisition module 210 is configured to acquire a grounding current signal of a neutral point of the hydraulic generator and a capacitance current value of a corresponding single camera end at a grounding fault point of the hydraulic generator;
the first calculation module 220 is configured to calculate an effective ground current value of a neutral point of the hydraulic generator by using a fourier transform method and a frequency domain fast algorithm for the ground current signal;
the second calculating module 230 is configured to calculate a ground current value of the hydraulic generator fault point based on the effective ground current value of the hydraulic generator neutral point and a capacitance current value of the corresponding single camera end at the hydraulic generator ground fault point.
The accurate testing device for the ground fault current of the hydraulic generator comprises a processor and a memory, wherein the acquisition module 210, the first calculation module 220, the second calculation module 230 and the like are all stored in the memory as program units, and the processor executes the program modules stored in the memory to realize corresponding functions.
The processor includes a kernel, and the kernel fetches the corresponding program unit from the memory. The inner core can be provided with one or more than one, and the accurate test method of the hydraulic generator ground fault current is realized by adjusting the parameters of the inner core.
The memory may include volatile memory, random Access Memory (RAM), and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM), among other forms in computer readable media, the memory including at least one memory chip.
The embodiment of the application provides a storage medium, and a program is stored on the storage medium, and the program is executed by a processor to realize the accurate testing method for the ground fault current of the hydraulic generator.
In one embodiment, the hydraulic generator ground fault current accurate test device provided by the application can be implemented in the form of a computer program, and the computer program can run on computer equipment. The memory of the computer device may store various program modules constituting the apparatus for accurately testing the ground fault current of the hydraulic generator, such as the acquisition module 210, the first calculation module 220, and the second calculation module 230 shown in fig. 7. The computer program comprising the program modules causes the processor to execute the steps of the method for accurately testing the ground fault current of the hydro-generator according to the embodiments of the present application described in the present specification.
The computer device may perform step 110 by means of the acquisition module 210 in the hydro-generator ground fault current accuracy testing apparatus as shown in fig. 7. The computer device may perform step 120 through the first computing module 220. The computer device may perform step 130 via the second computing module 230.
The embodiment of the application provides equipment, which comprises a processor, a memory and a program stored on the memory and capable of running on the processor, wherein the processor executes the program to realize the following steps:
step 110, obtaining a grounding current signal of a neutral point of the hydraulic generator and a capacitance current value of a corresponding single camera end at the grounding fault point of the hydraulic generator.
And 120, calculating the effective grounding current value of the neutral point of the hydraulic generator by adopting a Fourier series transformation method and a frequency domain fast algorithm aiming at the grounding current signal.
And 130, calculating the grounding current value of the hydraulic generator fault point based on the effective grounding current value of the hydraulic generator neutral point and the capacitance current value of the corresponding single camera end at the hydraulic generator grounding fault point.
In one embodiment, the ground current signal is a ground current digital signal, the method further comprising:
acquiring a grounding current acquisition signal of a neutral point of the hydraulic generator, and performing filtering processing on the grounding current acquisition signal through a signal conditioning circuit to acquire a grounding current analog signal;
and performing analog-to-digital conversion processing on the grounding current analog signal to obtain a grounding current digital signal.
In one embodiment, for the ground current signal, calculating an effective ground current value of a neutral point of the hydraulic generator by using a fourier transform method and a frequency domain fast algorithm includes:
the grounding current signals are subjected to sequence division based on a preset number of power frequency periodic waves to obtain a basic calculation sequencet(n)；
Computing basic computation sequences using fourier transform methodst(n) Frequency components of (2)
；
Using Pasteur formula to calculate the frequency component
And calculating an effective grounding current value of the neutral point of the hydraulic generator.
In one embodiment, the method further comprises: calculating a basic calculation sequence according to formula (15)t(n) Is of the synchronization time of (a)t syn (n)：
In the method, in the process of the invention,t syn (n) Represent the first
Basic calculation sequencet(n) Is a synchronous time of (1); 0.2 represents the time window length of the basic calculation sequence; />
Representing the sequence number of the basic calculation sequence.
In one embodiment, the basic calculation sequence is calculated using a Fourier transform methodt(n) Frequency of (2)Rate component
Comprising:
calculating a basic calculation sequence according to formulas (16) - (18)t(n) Frequency components of (2)
：
In the method, in the process of the invention,
and->
Representing a fourier series; />
Representing the frequency components; />
Representing the spectral line.
In one embodiment, the base calculation sequence is calculated according to equation (21)t(n)：
In the method, in the process of the invention,
representing the frequency components; />
Representing spectral lines; />
Representing discrete frequency points; />
Is the power frequency angular frequency, wherein
；/>
For spectral lines->
Is a phase angle of (c).
In one embodiment, the Pasteur equation is used to calculate the frequency component
Calculating an effective ground current value for a hydro-generator neutral point, comprising:
calculating the effective ground current value of the neutral point of the hydro-generator according to formulas (23) and (25):
in the method, in the process of the invention,
representation->
The effective grounding current value of the neutral point of the hydraulic generator at the moment; />
Representing the frequency components;I 0 (t) Representation oftAnd the effective grounding current value of the neutral point of the hydraulic generator at the moment.
In one embodiment, calculating the ground current value of the hydro-generator fault point based on the effective ground current value of the hydro-generator neutral point and the capacitance current value of the corresponding single camera end at the hydro-generator ground fault point comprises:
according to the formula (26), calculating the grounding current value of the fault point of the hydraulic generator:
in the method, in the process of the invention,
a ground current value representing a hydraulic generator fault point; k represents a proportionality coefficient;I Ctest representing a capacitance current value of a corresponding single camera end at a hydraulic generator ground fault point; />
Representation->
And the effective grounding current value of the neutral point of the hydraulic generator at the moment.
Fig. 6 schematically illustrates an overall structure diagram of a hydraulic generator ground fault current accuracy testing device according to an embodiment of the present application. As shown in fig. 6, the accurate test device for the ground fault current of the hydro-generator comprises: the system comprises a current transformer, a signal conditioning circuit, a synchronization module, a sampling module and a system running state setting module; the synchronization module is used for generating a dynamic zero crossing signali tr (n) The monitoring device is based on dynamic zero crossing signalsi tr (n) Triggering the data processing of the system running state setting module. The hydraulic generator ground fault current accurate testing device further comprises a man-machine interaction module, a display module, a database and the like. The hydraulic generator ground fault current accurate testing device is communicated with an upper computer through a man-machine interaction module.
According to the hydraulic generator grounding fault current accurate testing device, when a hydraulic generator is subjected to single-phase grounding fault, neutral point grounding current can be accurately measured, and the grounding current value of the hydraulic generator fault point can be calculated, so that damage of the grounding current to a stator core is effectively reflected.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.
The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, etc., such as Read Only Memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.
Computer-readable media include both permanent and non-permanent, removable and non-removable media, and information storage may be implemented by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises an element.
The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and changes may be made to the present application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. which are within the spirit and principles of the present application are intended to be included within the scope of the claims of the present application.
Claims (11)
1. The method for accurately testing the ground fault current of the hydraulic generator is characterized by comprising the following steps of:
acquiring a grounding current signal of a neutral point of the hydraulic generator and a capacitance current value of a single camera end corresponding to the grounding fault point of the hydraulic generator;
aiming at the grounding current signal, calculating an effective grounding current value of a neutral point of the hydraulic generator by adopting a Fourier series transformation method and a frequency domain fast algorithm;
and calculating the grounding current value of the hydraulic generator fault point based on the effective grounding current value of the hydraulic generator neutral point and the capacitance current value of the corresponding single camera end at the hydraulic generator grounding fault point.
2. The method of claim 1, wherein the ground current signal is a ground current digital signal, the method further comprising:
acquiring a grounding current acquisition signal of a neutral point of the hydraulic generator, and performing filtering processing on the grounding current acquisition signal through a signal conditioning circuit to acquire a grounding current analog signal;
and performing analog-to-digital conversion processing on the grounding current analog signal to obtain a grounding current digital signal.
3. The method of claim 1, wherein calculating an effective ground current value for a hydro-generator neutral point for the ground current signal using a fourier series transform method and a frequency domain fast algorithm comprises:
the grounding current signals are subjected to sequence division based on a preset number of power frequency periodic waves to obtain a basic calculation sequencet(n)；
Computing basic computation sequences using fourier transform methodst(n) Frequency components of (2)
；
Using Pasteur formula to calculate the frequency component
And calculating an effective grounding current value of the neutral point of the hydraulic generator.
4. A method according to claim 3, characterized in that the method further comprises: calculating a basic calculation sequence according to formula (15)t(n) Is of the synchronization time of (a)t syn (n)：
In the method, in the process of the invention,t syn (n) Represent the first
Basic calculation sequencet(n) Is a synchronous time of (1); 0.2 represents the time window length of the basic calculation sequence; />
Representing the sequence number of the basic calculation sequence.
5. A method according to claim 3, characterized in that the basic calculation sequence is calculated by means of fourier transformationt(n) Frequency components of (2)
Comprising:
calculating a basic calculation sequence according to formulas (16) - (18)t(n) Frequency components of (2)
：
In the method, in the process of the invention,
and->
Representing a fourier series; />
Representing the frequency components; />
Representing the spectral line.
6. The method of claim 5, wherein the basic calculation sequence is calculated according to formula (21)t(n)：
In the method, in the process of the invention,
representing frequencyA component; />
Representing spectral lines; />
Representing discrete frequency points; />
Is the power frequency angular frequency, wherein
；/>
For spectral lines->
Is a phase angle of (c).
7. The method of claim 5, wherein the frequency component is determined using a Pasteur equation
Calculating an effective ground current value for a hydro-generator neutral point, comprising:
calculating the effective ground current value of the neutral point of the hydro-generator according to formulas (23) and (25):
in the method, in the process of the invention,
representation->
The effective grounding current value of the neutral point of the hydraulic generator at the moment; />
Representing the frequency components;I 0 (t) Representation oftAnd the effective grounding current value of the neutral point of the hydraulic generator at the moment.
8. The method of claim 1, wherein calculating the hydro-generator fault point ground current value based on the hydro-generator neutral point effective ground current value and the hydro-generator ground fault point corresponding single-camera end capacitance current value comprises:
according to the formula (26), calculating the grounding current value of the fault point of the hydraulic generator:
in the method, in the process of the invention,
a ground current value representing a hydraulic generator fault point; k represents a proportionality coefficient;I Ctest representing a capacitance current value of a corresponding single camera end at a hydraulic generator ground fault point; />
Representation->
And the effective grounding current value of the neutral point of the hydraulic generator at the moment.
9. An accurate testing arrangement of hydraulic generator earth fault current, characterized in that, the device includes:
the acquisition module is used for acquiring a grounding current signal of a neutral point of the hydraulic generator and a capacitance current value of a corresponding single camera end at a grounding fault point of the hydraulic generator;
the first calculation module is used for calculating the effective grounding current value of the neutral point of the hydraulic generator by adopting a Fourier series transformation method and a frequency domain fast algorithm aiming at the grounding current signal;
and the second calculation module is used for calculating the grounding current value of the hydraulic generator fault point based on the effective grounding current value of the hydraulic generator neutral point and the capacitance current value of the corresponding single camera end at the hydraulic generator grounding fault point.
10. A processor configured to perform the hydro-generator ground fault current accuracy test method of any one of claims 1 to 8.
11. A machine-readable storage medium having instructions stored thereon, which when executed by a processor cause the processor to be configured to perform the hydro-generator ground fault current accuracy test method of any one of claims 1 to 8.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5691643A (en) * | 1994-10-11 | 1997-11-25 | Kabushiki Kaisha Toshiba | Ground fault detecting apparatus and method for detecting ground fault of field circuit and exciting circuit by detecting ground fault current flowing from ground to neutral point of exciting circuit |
| US20160041216A1 (en) * | 2013-03-29 | 2016-02-11 | Beijing Inhand Networks Technology Co., Ltd. | Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network |
| US20160266206A1 (en) * | 2015-03-11 | 2016-09-15 | Siemens Energy, Inc. | Generator neutral ground monitoring device utilizing direct current component measurement and analysis |
| RU2016141795A (en) * | 2016-10-24 | 2018-04-24 | Общество с ограниченной ответственностью "НПП Бреслер" (ООО "НПП Бреслер") | Method for automatic compensation of single-phase earth fault current in a network with an arcing reactor in neutral |
| CN111106600A (en) * | 2019-12-30 | 2020-05-05 | 国电科学技术研究院有限公司 | Parameter optimization method for high-impedance grounding device of neutral point of large and medium hydraulic generator |
| CN111562464A (en) * | 2020-05-12 | 2020-08-21 | 国网山东省电力公司电力科学研究院 | Parameter online testing method, storage medium and device of neutral point ungrounded system |
| CN111650509A (en) * | 2020-05-12 | 2020-09-11 | 浙江浙能电力股份有限公司台州发电厂 | Fault judgment method and device for brushless excitation motor, computer equipment and medium |
| CN113203950A (en) * | 2021-04-30 | 2021-08-03 | 华中科技大学 | Method and system for diagnosing ground fault degree of generator stator of marine nuclear power platform |
| CN114966373A (en) * | 2022-05-24 | 2022-08-30 | 江苏科技大学 | Method and system for testing parameters of analog-to-digital conversion chip of integrated circuit |
| CN115144687A (en) * | 2022-06-10 | 2022-10-04 | 国家能源集团科学技术研究院有限公司 | Parameter simulation test method for generator neutral point grounding system |
| CN115327294A (en) * | 2022-07-27 | 2022-11-11 | 云南电网有限责任公司曲靖供电局 | Current calculation method for low-current ground fault |
| CN115792485A (en) * | 2022-05-26 | 2023-03-14 | 国网新疆电力有限公司超高压分公司 | Low-voltage loop grounding line selection and grounding point range confirmation method and device |
-
2023
- 2023-05-23 CN CN202310579380.8A patent/CN116298883B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5691643A (en) * | 1994-10-11 | 1997-11-25 | Kabushiki Kaisha Toshiba | Ground fault detecting apparatus and method for detecting ground fault of field circuit and exciting circuit by detecting ground fault current flowing from ground to neutral point of exciting circuit |
| US20160041216A1 (en) * | 2013-03-29 | 2016-02-11 | Beijing Inhand Networks Technology Co., Ltd. | Method and system for detecting and locating single-phase ground fault on low current grounded power-distribution network |
| US20160266206A1 (en) * | 2015-03-11 | 2016-09-15 | Siemens Energy, Inc. | Generator neutral ground monitoring device utilizing direct current component measurement and analysis |
| RU2016141795A (en) * | 2016-10-24 | 2018-04-24 | Общество с ограниченной ответственностью "НПП Бреслер" (ООО "НПП Бреслер") | Method for automatic compensation of single-phase earth fault current in a network with an arcing reactor in neutral |
| CN111106600A (en) * | 2019-12-30 | 2020-05-05 | 国电科学技术研究院有限公司 | Parameter optimization method for high-impedance grounding device of neutral point of large and medium hydraulic generator |
| CN111562464A (en) * | 2020-05-12 | 2020-08-21 | 国网山东省电力公司电力科学研究院 | Parameter online testing method, storage medium and device of neutral point ungrounded system |
| CN111650509A (en) * | 2020-05-12 | 2020-09-11 | 浙江浙能电力股份有限公司台州发电厂 | Fault judgment method and device for brushless excitation motor, computer equipment and medium |
| CN113203950A (en) * | 2021-04-30 | 2021-08-03 | 华中科技大学 | Method and system for diagnosing ground fault degree of generator stator of marine nuclear power platform |
| CN114966373A (en) * | 2022-05-24 | 2022-08-30 | 江苏科技大学 | Method and system for testing parameters of analog-to-digital conversion chip of integrated circuit |
| CN115792485A (en) * | 2022-05-26 | 2023-03-14 | 国网新疆电力有限公司超高压分公司 | Low-voltage loop grounding line selection and grounding point range confirmation method and device |
| CN115144687A (en) * | 2022-06-10 | 2022-10-04 | 国家能源集团科学技术研究院有限公司 | Parameter simulation test method for generator neutral point grounding system |
| CN115327294A (en) * | 2022-07-27 | 2022-11-11 | 云南电网有限责任公司曲靖供电局 | Current calculation method for low-current ground fault |
Non-Patent Citations (2)
| Title |
|---|
| 张忠强: "钢铁厂余热电站发电机中性点接地方式的选择及计算", 《自动化与仪器仪表》, no. 7, pages 1 - 4 * |
| 田凤兰等: "基于小波包分解的小电阻接地系统 高阻接地故障检测方法", 《电瓷避雷器》, no. 1, pages 179 - 190 * |
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