CN110988624B - Detection method and system for intermittent partial discharge signal - Google Patents
Detection method and system for intermittent partial discharge signal Download PDFInfo
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- CN110988624B CN110988624B CN201911229443.7A CN201911229443A CN110988624B CN 110988624 B CN110988624 B CN 110988624B CN 201911229443 A CN201911229443 A CN 201911229443A CN 110988624 B CN110988624 B CN 110988624B
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Abstract
The embodiment of the invention discloses a method and a system for detecting intermittent partial discharge signals, which are used for electrical equipment. The detection method comprises the following steps: starting from the initial phase of a power grid period of 0 degrees, synchronizing with the power grid period, and monitoring each pulse signal of electrical equipment; if any pulse signal of the current power grid period meets the trigger condition at the current moment, acquiring each pulse signal with preset duration before and after the current moment; sampling the acquired pulse sequence phase characteristic map data of each pulse signal; and determining the pulse signal meeting the triggering condition to be an intermittent partial discharge signal or an external interference signal in the electrical equipment according to the type of the acquired sensor meeting the pulse signal of the triggering condition and the pulse amplitude of the sampled pulse signal meeting the triggering condition. The embodiment of the invention can effectively detect the intermittent partial discharge signal and reduce the leakage rate.
Description
Technical Field
The invention relates to the technical field of partial discharge, in particular to a method and a system for detecting an intermittent partial discharge signal.
Background
Some defects are inevitably generated in the production, transportation, installation and operation processes of electrical equipment such as GIS, transformers, switch cabinets and the like due to manufacturing processes, assembly quality, material aging, mechanical vibration and the like, common defects mainly include metal tip defects, free metal particle defects, suspension defects, solid insulation defects and the like, and partial discharge caused by the defects is not only a sign of internal insulation degradation of the electrical equipment, but also an important reason of the insulation degradation. In the partial discharge signals, some signals have the characteristics of long intermittent time and sparse discharge, and the intermittent partial discharge signals are untimely, may be suddenly discharged for a period of time, and may also be discharged once at a time, so that the signals are not easily acquired by online monitoring equipment or are easily mistakenly judged as random interference.
At present, a plurality of live detection devices and online monitoring devices are applied to monitoring of partial discharge, monitoring data are collected and stored regularly or at regular time by adopting detection technologies such as ultrahigh frequency and high frequency current, and the data are judged or uploaded to a cloud end by an artificial expert for diagnosis and analysis. The detection period of the charged detection is long, only partial defects can be found, and the online monitoring device has a good application effect on partial discharge with good repeatability. However, for the intermittent partial discharge signal, due to the characteristics of uncertainty of discharge time, scattered frequency, sporadic nature, sparseness and the like, the online monitoring device in the prior art is difficult to effectively distinguish the intermittent partial discharge signal from the random interference signal, so that the problem of false alarm or false alarm is generated.
Disclosure of Invention
The embodiment of the invention provides a method and a system for detecting an intermittent partial discharge signal, which aim to solve the problem that the prior art is difficult to effectively distinguish the intermittent partial discharge signal from a random interference signal.
In a first aspect, a method for detecting an intermittent partial discharge signal is provided, and is used for an electrical device, and the method includes:
starting from the initial phase of a power grid period of 0 degrees, synchronizing with the power grid period, and monitoring each pulse signal of electrical equipment;
if any pulse signal of the current power grid period meets the trigger condition at the current moment, acquiring each pulse signal with preset duration before and after the current moment;
sampling the acquired pulse sequence phase characteristic map data of each pulse signal;
determining the pulse signal meeting the triggering condition to be an intermittent partial discharge signal or an external interference signal in the electrical equipment according to the type of the acquired sensor meeting the pulse signal of the triggering condition and the pulse amplitude of the sampled pulse signal meeting the triggering condition;
wherein the trigger condition comprises:
the pulse amplitude of any pulse signal at the current moment of the current power grid period is greater than the pulse threshold of the previous power grid period; and the number of the first and second groups,
the pulse signal above the pulse threshold of the previous grid cycle has the following characteristics: | t0.5Vu-tv|≤Tu、|t0.5Vd-tv|≤TdAnd t0.5Vu<tv<t0.5Vd，t0.5VuRepresenting the moment at which the pulse signal rises from 0.1 to 0.5 times the pulse amplitude, tvRepresenting the moment at which the pulse signal rises from 0.1 to 0.9 times the pulse amplitude, t0.5VdRepresenting the moment at which the pulse signal decreases from 0.9 times the pulse amplitude to 0.5 times the pulse amplitude, TuIndicating a rising pulse width threshold, TdIndicating a falling pulse width threshold.
In a second aspect, there is provided a detection system for intermittent partial discharge signals for an electrical device, the detection system comprising:
the monitoring module is used for monitoring each pulse signal of the electrical equipment from the initial phase of the power grid period as 0 degrees and synchronizing with the power grid period;
the acquisition module is used for acquiring each pulse signal with preset duration before and after the current moment if any pulse signal of the current power grid period is monitored to meet the trigger condition at the current moment;
the sampling module is used for sampling the acquired pulse sequence phase characteristic map data of each pulse signal;
the determining module is used for determining the pulse signal meeting the triggering condition to be an intermittent partial discharge signal or an external interference signal in the electrical equipment according to the type of the acquired pulse signal meeting the triggering condition and the pulse amplitude of the sampled pulse signal meeting the triggering condition;
wherein the trigger condition comprises:
the pulse amplitude of any pulse signal at the current moment of the current power grid period is greater than the pulse threshold of the previous power grid period; and the number of the first and second groups,
the pulse signal above the pulse threshold of the previous grid cycle has the following characteristics: | t0.5Vu-tv|≤Tu、|t0.5Vd-tv|≤TdAnd t0.5Vu<tv<t0.5Vd，t0.5VuRepresenting the moment at which the pulse signal rises from 0.1 to 0.5 times the pulse amplitude, tvRepresenting the moment at which the pulse signal rises from 0.1 to 0.9 times the pulse amplitude, t0.5VdRepresenting the moment at which the pulse signal decreases from 0.9 times the pulse amplitude to 0.5 times the pulse amplitude, TuIndicating a rising pulse width threshold, TdIndicating a falling pulse width threshold.
Therefore, the embodiment of the invention can effectively detect the intermittent partial discharge signal, particularly can effectively detect the intermittent partial discharge signal of the abnormal electrical equipment, and can effectively detect the intermittent partial discharge signal of the abnormal electrical equipment when the abnormal electrical equipment cannot be overhauled in a power failure way, the intermittent partial discharge signals are continuously acquired in real time, and a trigger acquisition mechanism is adopted to extract occasional and sparse intermittent partial discharge signals, so that the condition that the intermittent partial discharge signals are omitted due to timing acquisition is avoided, the leakage rate of the partial discharge signals is reduced, meanwhile, only the data of the trigger moment of the storage signal is needed to be collected, the requirement of the storage resource is reduced, the contradiction between the two requirements of high sampling rate and low storage resource is solved, by comparing the signals of the noise sensor and the ultrahigh frequency sensor, the intermittent partial discharge signal and the external interference signal can be effectively distinguished so as to further improve the accuracy of defect diagnosis.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention 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 that other drawings can be obtained according to these drawings without inventive labor.
Fig. 1 is a flowchart of a detection method of an intermittent partial discharge signal according to an embodiment of the present invention;
FIG. 2 is a functional flow diagram of data collected by a preferred embodiment of the present invention;
fig. 3 is a block diagram of a system for detecting an intermittent partial discharge signal according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. 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.
The embodiment of the invention discloses a method for detecting intermittent partial discharge signals. The detection method is used for electrical equipment, such as GIS, transformers, switch cabinets and the like. As shown in fig. 1, the detection method includes the following steps:
step S101: and monitoring each pulse signal of the electrical equipment from the initial phase of the power grid period of 0 DEG in synchronization with the power grid period.
One grid cycle is typically 0.02 s. Specifically, monitoring and caching can be performed through the FPGA chip. It should be understood that the following steps may be stopped when the total number of buffered single pulses reaches the maximum number of buffered pulses, and may be performed again when the buffered pulses are read clear and the total number of buffered single pulses is less than the maximum number of buffered pulses.
Typically, multiple sensors may be provided, each sensor being responsible for each pulse signal. For example, taking a GIS device as an example, the sensor may be deployed on the GIS device.
Step S102: if any pulse signal of the current power grid period meets the trigger condition at the current moment, collecting all pulse signals with preset time length before and after the current moment.
The preset duration before and after the current time refers to a time interval formed by the time before the current time, the current time and the continuous time after the current time. Generally, the selected time before the current time is shorter than the selected time after the current time, and can be determined empirically. The specific duration of the preset duration may also be set empirically, for example, the preset duration is 1 s.
Specifically, the trigger conditions include:
(1) the pulse amplitude of any pulse signal at the current moment of the current power grid cycle is larger than the pulse threshold of the previous power grid cycle.
It should be understood that pulse amplitude refers to the maximum amplitude of a pulse that changes from "0" to "1".
Specifically, the pulse threshold of the previous grid cycle is calculated by the following formula:
wherein N isjIndicating the pulse threshold for the monitored j grid cycle, it should be understood that the current grid cycle is the j +1 grid cycle. m represents the total number of grid cycles monitored. n represents the total number of equal intervals of each grid cycle and can be set through experience. FjiThe maximum value of the pulse amplitudes of the pulse signals representing the ith interval of the monitored jth grid cycle can be obtained by measurement, from which the maximum one can be determined. k represents a margin coefficient, which can be determined empirically, k is greater than or equal to 1 and less than or equal to SNR, which represents the signal-to-noise ratio, and can be obtained by measurement.
(2) The pulse signal above the pulse threshold of the previous grid cycle has the following characteristics:
|t0.5Vu-tv|≤Tu；
|t0.5Vd-tv|≤Td；
t0.5Vu<tv<t0.5Vd。
wherein, t0.5VuRepresenting the pulse signal rising from 0.1 to 0.5 times the pulse amplitudeThe time of day. t is tvIndicating the moment when the pulse signal rises from 0.1 times the pulse amplitude to 0.9 times the pulse amplitude. t is t0.5VdIndicating the moment when the pulse signal decreases from 0.9 times the pulse amplitude to 0.5 times the pulse amplitude. T isuThe threshold value for the rising pulse width is empirically predetermined and in a preferred embodiment of the invention is 10 ms. T isdThe threshold value for the falling pulse width is empirically predetermined and in a preferred embodiment of the invention, is 20 ms.
In actual operation, after the trigger condition is reached, the pulse signals before and after triggering can be stored through the FPGA chip, rather than storing all pulse data. The sampling frequency of the ultrahigh frequency required by the positioning of the partial discharge defect is higher, so that a large data volume is generated, and the triggering mode is adopted for acquisition and storage, so that the stored data volume can be reduced, and the storage resource requirement generated by a high sampling rate is reduced.
Step S103: sampling the acquired pulse sequence phase characteristic map data of each pulse signal.
Specifically, the sampling process is performed as follows:
(1) and dividing the point number of the pulse signal acquired each time into a plurality of intervals according to the sampling ratio of the pulse sequence phase characteristic spectrum.
The number of intervals is the number of points of the pulse signal/sampling ratio. Generally, pulse data of the partial discharge signal can be acquired through two acquisition modes of pulse acquisition and pulse sequence phase characteristic map (PRPS) acquisition. The embodiment of the invention adopts the pulse sequence phase characteristic map data to judge whether the pulse signal is an intermittent partial discharge signal.
(2) And extracting the point with the maximum pulse amplitude of the pulse signal in each interval as a sample of the pulse sequence phase characteristic map.
Since the pulse amplitude of each pulse signal may be different, the pulse signal having the largest pulse amplitude in the interval is selected as the sample.
Step S104: and determining the pulse signal meeting the triggering condition to be an intermittent partial discharge signal or an external interference signal in the electrical equipment according to the type of the acquired pulse signal meeting the triggering condition and the pulse amplitude of the sampled pulse signal meeting the triggering condition.
The sensor adopted by the embodiment of the invention comprises: ultrahigh frequency sensors and noise sensors. The sampling rate of the ultrahigh frequency sensor is 2.5 GHz. The sampling rate of the noise sensor is 2.5 GHz. Because the ultrahigh frequency partial discharge signal is interfered a lot, and the characteristics of the interference signal are similar to those of the partial discharge signal, the noise sensor is required to eliminate the spatial interference on the ultrahigh frequency partial discharge signal.
Different numbers of corresponding sensors may be provided according to particular needs. In a preferred embodiment of the invention, 3 uhf sensors and 1 noise sensor may be provided.
Specifically, the steps include the following conditions:
(1) only the noise sensor acquires a pulse signal that satisfies the trigger condition.
And if the sensor which acquires the pulse signal meeting the triggering condition is a noise sensor, determining that the pulse signal meeting the triggering condition is an external interference signal.
(2) Only the ultrahigh frequency sensor acquires the pulse signal meeting the trigger condition.
And if the sensor which acquires the pulse signal meeting the triggering condition is an ultrahigh frequency sensor, determining that the pulse signal meeting the triggering condition is an intermittent partial discharge signal in the electrical equipment.
(3) The ultrahigh frequency sensor and the noise sensor both acquire pulse signals meeting triggering conditions.
If the sensors for acquiring the pulse signals meeting the triggering conditions comprise the ultrahigh frequency sensor and the noise sensor, judging whether the pulse signals meeting the triggering conditions acquired by the ultrahigh frequency sensor and the pulse sequence phase characteristic maps of the pulse signals meeting the triggering conditions acquired by the noise sensor have the same characteristics.
The characteristics of the pulse sequence phase characteristic map refer to discharge times, skewness, projection degree, asymmetry degree, correlation coefficient, pulse concentration degree and dispersion degree. The characteristics can be obtained by counting the discharge frequency phase distribution, the discharge amplitude phase distribution and the discharge frequency period distribution of the pulse sequence phase characteristic map.
And determining that the pulse signal meeting the triggering condition acquired by the ultrahigh frequency sensor is an intermittent partial discharge signal in the electrical equipment if the pulse signal meeting the triggering condition acquired by the ultrahigh frequency sensor and the pulse sequence phase characteristic map meeting the triggering condition acquired by the noise sensor have different characteristics.
It should be understood that in this case, the pulse signal which satisfies the trigger condition and is collected by the noise sensor is an external interference signal.
And thirdly, if the pulse signals meeting the triggering conditions acquired by the ultrahigh frequency sensor and the pulse sequence phase characteristic spectrums of the pulse signals meeting the triggering conditions acquired by the noise sensor have the same characteristics, comparing the pulse amplitude of the pulse signals meeting the triggering conditions acquired by the ultrahigh frequency sensor with the pulse amplitude of the pulse signals meeting the triggering conditions acquired by the noise sensor.
It should be understood that the pulse amplitude of the pulse signal collected by the uhf sensor for comparison and the pulse amplitude of the pulse signal collected by the noise sensor are pulse signals collected at the same time.
And fourthly, if the pulse amplitude of the pulse signal which meets the triggering condition and is acquired by the ultrahigh frequency sensor is not less than the pulse amplitude of the pulse signal which meets the triggering condition and is acquired by the noise sensor, determining the pulse signal which meets the triggering condition and is acquired by the ultrahigh frequency sensor to be an intermittent partial discharge signal in the electrical equipment.
It should be understood that in this case, the pulse signal which satisfies the trigger condition and is collected by the noise sensor is an external interference signal.
And fifthly, if the pulse amplitude of the pulse signal which meets the triggering condition and is collected by the ultrahigh frequency sensor is smaller than that of the pulse signal which meets the triggering condition and is collected by the noise sensor, determining that the pulse signal which meets the triggering condition and is collected by the ultrahigh frequency sensor is an external interference signal.
It should be understood that in this case, the pulse signal which satisfies the trigger condition and is collected by the noise sensor is an external interference signal.
In addition, after the intermittent partial discharge signal in the electrical equipment is determined by the detection method of the embodiment of the invention, the defect type and the defect position can be identified according to the intermittent partial discharge signal. As shown in fig. 2, in the process of acquiring the pulse signal, the pulse signal may also be acquired by an ultrasonic sensor with a sampling rate of 1MHz, and specifically, 3 ultrasonic sensors may be provided. The defect position can be determined by the existing electric positioning method by using the ultrahigh frequency 2.5GHz pulse atlas data (without sampling) of the intermittent partial discharge signals acquired by the ultrahigh frequency sensor, the defect position can be determined by the existing acoustic positioning method by using the ultrasonic wave 1MHz pulse atlas data (without sampling) of the intermittent partial discharge signals acquired by the ultrasonic sensor, and the defect position can be determined by the existing acoustic-electric combined positioning method by using the ultrahigh frequency 1GHz pulse atlas data (without sampling) of the intermittent partial discharge signals acquired by the ultrahigh frequency sensor and the ultrasonic wave 1MHz pulse atlas data (without sampling) of the intermittent partial discharge signals acquired by the ultrasonic sensor. The defect type can be diagnosed by the existing method by using the ultrahigh frequency pulse sequence phase characteristic map data (needing pre-sampling) of the intermittent partial discharge signals acquired by the ultrahigh frequency sensor, the defect type can be diagnosed by the existing method by using the ultrasonic pulse sequence phase characteristic map data (needing pre-sampling) of the intermittent partial discharge signals acquired by the ultrasonic sensor, and the defect type can be diagnosed by the existing method by using the noise pulse sequence phase characteristic map data (needing pre-sampling) acquired by the noise sensor. And combining the results of the combined judgment of the modes to obtain more accurate defect positions and defect types. The sampling manner of the pulse sequence phase characteristic map data is as described above. The sampling mode of the ultrahigh frequency pulse map data is to divide the number of stored pulse points into equal intervals according to the sampling frequency of the ultrasonic wave, the interval number is equal to the sampling frequency of the ultrasonic wave, and the point with the maximum pulse amplitude is extracted in the interval to be used as the sampling of the ultrahigh frequency pulse map.
In summary, the method for detecting intermittent partial discharge signals according to the embodiments of the present invention can effectively detect intermittent partial discharge signals, and particularly, for electrical equipment that has abnormal conditions, in case of failure to perform power failure maintenance, the intermittent partial discharge signals are continuously acquired in real time, and a trigger acquisition mechanism is adopted to extract occasional and sparse intermittent partial discharge signals, so that the condition that the intermittent partial discharge signals are omitted due to timing acquisition is avoided, the leakage rate of the partial discharge signals is reduced, meanwhile, only the data of the trigger moment of the storage signal is needed to be collected, the requirement of the storage resource is reduced, the contradiction between the two requirements of high sampling rate and low storage resource is solved, by comparing the signals of the noise sensor and the ultrahigh frequency sensor, the intermittent partial discharge signal and the external interference signal can be effectively distinguished so as to further improve the accuracy of defect diagnosis.
The embodiment of the invention also discloses a detection system of the intermittent partial discharge signal. The detection system is used for electrical equipment. As shown in fig. 3, the detection system includes:
and the monitoring module 301 is configured to start from an initial phase of a power grid cycle being 0 ° and monitor each pulse signal of the electrical device in synchronization with the power grid cycle.
The acquisition module 302 is configured to acquire each pulse signal of a preset duration before and after a current time if it is monitored that any pulse signal of a current power grid period meets a trigger condition at the current time.
And the sampling module 303 is configured to sample the acquired pulse sequence phase characteristic map data of each pulse signal.
The determining module 304 is configured to determine, according to the type of the acquired sensor of the pulse signal meeting the trigger condition and the pulse amplitude of the pulse signal meeting the trigger condition after sampling processing, that the pulse signal meeting the trigger condition is an intermittent partial discharge signal or an external interference signal inside the electrical device.
Wherein the trigger condition comprises:
the pulse amplitude of any pulse signal at the current moment of the current power grid cycle is larger than the pulse threshold of the previous power grid cycle.
The calculation formula of the pulse threshold value of the previous grid cycle is as follows:
And, the pulsed signal being greater than the pulsed threshold of the previous grid cycle has the following characteristics: | t0.5Vu-tv|≤Tu、|t0.5Vd-tv|≤TdAnd t0.5Vu<tv<t0.5Vd，t0.5VuRepresenting the moment at which the pulse signal rises from 0.1 to 0.5 times the pulse amplitude, tvRepresenting the moment at which the pulse signal rises from 0.1 to 0.9 times the pulse amplitude, t0.5VdRepresenting the moment at which the pulse signal decreases from 0.9 times the pulse amplitude to 0.5 times the pulse amplitude, TuIndicating a rising pulse width threshold, TdIndicating a falling pulse width threshold.
Preferably, the determining module 304 includes:
the first determining submodule is used for determining that the pulse signal meeting the triggering condition is an external interference signal if the sensor collecting the pulse signal meeting the triggering condition is a noise sensor.
And the second determining submodule is used for determining that the pulse signal meeting the triggering condition is an intermittent partial discharge signal in the electrical equipment if the sensor collecting the pulse signal meeting the triggering condition is an ultrahigh frequency sensor.
Preferably, the determining module 304 further comprises:
and the judging submodule is used for judging whether the pulse signals meeting the triggering conditions acquired by the ultrahigh frequency sensor and the pulse sequence phase characteristic spectrum of the pulse signals meeting the triggering conditions acquired by the noise sensor are the same or not if the sensors acquiring the pulse signals meeting the triggering conditions comprise the ultrahigh frequency sensor and the noise sensor.
And the third determining submodule is used for determining that the pulse signal meeting the triggering condition acquired by the ultrahigh frequency sensor is an intermittent partial discharge signal in the electrical equipment if the pulse signal meeting the triggering condition acquired by the ultrahigh frequency sensor and the pulse sequence phase characteristic spectrum meeting the triggering condition acquired by the noise sensor have different characteristics.
And the comparison submodule is used for comparing the pulse amplitude of the pulse signal meeting the trigger condition acquired by the ultrahigh frequency sensor with the pulse amplitude of the pulse signal meeting the trigger condition acquired by the noise sensor if the pulse signal meeting the trigger condition acquired by the ultrahigh frequency sensor and the pulse sequence phase characteristic spectrum meeting the trigger condition acquired by the noise sensor have the same characteristics.
And the fourth determining submodule is used for determining that the pulse signal meeting the triggering condition acquired by the ultrahigh frequency sensor is an intermittent partial discharge signal in the electrical equipment if the pulse amplitude of the pulse signal meeting the triggering condition acquired by the ultrahigh frequency sensor is not less than the pulse amplitude of the pulse signal meeting the triggering condition acquired by the noise sensor.
And the fifth determining submodule is used for determining that the pulse signal meeting the triggering condition acquired by the ultrahigh frequency sensor is an external interference signal if the pulse amplitude of the pulse signal meeting the triggering condition acquired by the ultrahigh frequency sensor is smaller than the pulse amplitude of the pulse signal meeting the triggering condition acquired by the noise sensor.
Preferably, the sampling module 303 includes:
and the dividing submodule is used for dividing the point number of the pulse signal acquired each time into a plurality of intervals according to the sampling ratio of the pulse sequence phase characteristic map, wherein the interval number is the point number/sampling ratio of the pulse signal.
And the sampling sub-module is used for sampling the point with the maximum pulse amplitude of the pulse signal in each interval as the sampling of the pulse sequence phase characteristic map.
For the device embodiment, since it is basically similar to the method embodiment, the description is simple, and for the relevant points, refer to the partial description of the method embodiment.
In summary, the detection system for intermittent partial discharge signals according to the embodiments of the present invention can effectively detect intermittent partial discharge signals, and particularly, for electrical equipment that has abnormal conditions, in the case of failure to perform power failure maintenance, the intermittent partial discharge signals are continuously acquired in real time, and a trigger acquisition mechanism is adopted to extract occasional and sparse intermittent partial discharge signals, so that the condition that the intermittent partial discharge signals are omitted due to timing acquisition is avoided, the leakage rate of the partial discharge signals is reduced, meanwhile, only the data of the trigger moment of the storage signal is needed to be collected, the requirement of the storage resource is reduced, the contradiction between the two requirements of high sampling rate and low storage resource is solved, by comparing the signals of the noise sensor and the ultrahigh frequency sensor, the intermittent partial discharge signal and the external interference signal can be effectively distinguished so as to further improve the accuracy of defect diagnosis.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A detection method of intermittent partial discharge signals for an electrical device, the detection method comprising:
starting from the initial phase of a power grid period of 0 degrees, synchronizing with the power grid period, and monitoring each pulse signal of electrical equipment;
if any pulse signal of the current power grid period meets the trigger condition at the current moment, acquiring each pulse signal with preset duration before and after the current moment;
sampling the acquired pulse sequence phase characteristic map data of each pulse signal;
determining the pulse signal meeting the triggering condition to be an intermittent partial discharge signal or an external interference signal in the electrical equipment according to the type of the acquired sensor meeting the pulse signal of the triggering condition and the pulse amplitude of the sampled pulse signal meeting the triggering condition;
wherein the trigger condition comprises:
the pulse amplitude of any pulse signal at the current moment of the current power grid period is greater than the pulse threshold of the previous power grid period; and the number of the first and second groups,
the pulse signal above the pulse threshold of the previous grid cycle has the following characteristics: | t0.5Vu-tv|≤Tu、|t0.5Vd-tv|≤TdAnd t0.5Vu<tv<t0.5Vd，t0.5VuRepresenting the moment at which the pulse signal rises from 0.1 to 0.5 times the pulse amplitude, tvRepresenting the moment at which the pulse signal rises from 0.1 to 0.9 times the pulse amplitude, t0.5VdRepresenting the moment at which the pulse signal decreases from 0.9 times the pulse amplitude to 0.5 times the pulse amplitude, TuIndicates a risePulse width threshold, TdIndicating a falling pulse width threshold.
2. The detection method according to claim 1, characterized in that: the calculation of the pulse threshold for the previous grid cycle is as follows:
wherein N isjIndicating the pulse threshold for the j grid cycle monitored, m indicating the total number of grid cycles monitored, n indicating the total number of equal intervals per grid cycle, FjiAnd the maximum value of the pulse amplitude of the pulse signal of the ith interval of the monitored jth power grid cycle is represented, k represents a margin coefficient, k is more than or equal to 1 and is less than or equal to SNR, and SNR represents a signal-to-noise ratio.
3. The detection method according to claim 1, wherein the step of determining that the pulse signal satisfying the trigger condition is an intermittent partial discharge signal or an external interference signal inside the electrical device comprises:
if the sensor which acquires the pulse signal meeting the triggering condition is a noise sensor, determining that the pulse signal meeting the triggering condition is an external interference signal;
and if the sensor which acquires the pulse signal meeting the triggering condition is an ultrahigh frequency sensor, determining that the pulse signal meeting the triggering condition is an intermittent partial discharge signal in the electrical equipment.
4. The detection method according to claim 1, wherein the step of determining that the pulse signal satisfying the trigger condition is an intermittent partial discharge signal or an external interference signal inside the electrical device further comprises:
if the sensors which acquire the pulse signals meeting the triggering conditions comprise ultrahigh frequency sensors and noise sensors, judging whether the pulse signals meeting the triggering conditions acquired by the ultrahigh frequency sensors and the pulse sequence phase characteristic maps of the pulse signals meeting the triggering conditions acquired by the noise sensors have the same characteristics;
if the pulse signals meeting the trigger condition and the pulse sequence phase characteristic maps of the pulse signals meeting the trigger condition and collected by the ultrahigh frequency sensor are different in characteristics, determining that the pulse signals meeting the trigger condition and collected by the ultrahigh frequency sensor are intermittent partial discharge signals in the electrical equipment;
if the pulse signals meeting the trigger condition and the pulse sequence phase characteristic maps of the pulse signals meeting the trigger condition and collected by the ultrahigh frequency sensor have the same characteristics, comparing the pulse amplitude of the pulse signals meeting the trigger condition and collected by the ultrahigh frequency sensor with the pulse amplitude of the pulse signals meeting the trigger condition and collected by the noise sensor;
if the pulse amplitude of the pulse signal which meets the trigger condition and is acquired by the ultrahigh frequency sensor is not less than the pulse amplitude of the pulse signal which meets the trigger condition and is acquired by the noise sensor, determining that the pulse signal which meets the trigger condition and is acquired by the ultrahigh frequency sensor is an intermittent partial discharge signal in the electrical equipment;
and if the pulse amplitude of the pulse signal which meets the trigger condition and is acquired by the ultrahigh frequency sensor is smaller than the pulse amplitude of the pulse signal which meets the trigger condition and is acquired by the noise sensor, determining that the pulse signal which meets the trigger condition and is acquired by the ultrahigh frequency sensor is an external interference signal.
5. The detection method according to claim 1, wherein the step of sampling the acquired pulse sequence phase characteristic map data of each pulse signal comprises:
dividing the point number of the pulse signal acquired each time into a plurality of intervals according to the sampling ratio of the pulse sequence phase characteristic map, wherein the interval number is the point number/sampling ratio of the pulse signal;
and sampling the point with the maximum pulse amplitude of the pulse signal in each interval as a sampling of the pulse sequence phase characteristic map.
6. A detection system for an intermittent partial discharge signal for an electrical device, the detection system comprising:
the monitoring module is used for monitoring each pulse signal of the electrical equipment from the initial phase of the power grid period as 0 degrees and synchronizing with the power grid period;
the acquisition module is used for acquiring each pulse signal with preset duration before and after the current moment if any pulse signal of the current power grid period is monitored to meet the trigger condition at the current moment;
the sampling module is used for sampling the acquired pulse sequence phase characteristic map data of each pulse signal;
the determining module is used for determining the pulse signal meeting the triggering condition to be an intermittent partial discharge signal or an external interference signal in the electrical equipment according to the type of the acquired pulse signal meeting the triggering condition and the pulse amplitude of the sampled pulse signal meeting the triggering condition;
wherein the trigger condition comprises:
the pulse amplitude of any pulse signal at the current moment of the current power grid period is greater than the pulse threshold of the previous power grid period; and the number of the first and second groups,
the pulse signal above the pulse threshold of the previous grid cycle has the following characteristics: | t0.5Vu-tv|≤Tu、|t0.5Vd-tv|≤TdAnd t0.5Vu<tv<t0.5Vd，t0.5VuRepresenting the moment at which the pulse signal rises from 0.1 to 0.5 times the pulse amplitude, tvRepresenting the moment at which the pulse signal rises from 0.1 to 0.9 times the pulse amplitude, t0.5VdIndicating that the pulse signal is from 0.9 times the pulse amplitudeTime at which the degree drops to 0.5 times the pulse amplitude, TuIndicating a rising pulse width threshold, TdIndicating a falling pulse width threshold.
7. The detection system of claim 6, wherein: the calculation formula of the pulse threshold value of the previous power grid period is as follows:
wherein N isjIndicating the pulse threshold for the j grid cycle monitored, m indicating the total number of grid cycles monitored, n indicating the total number of equal intervals per grid cycle, FjiAnd the maximum value of the pulse amplitude of the pulse signal of the ith interval of the monitored jth power grid cycle is represented, k represents a margin coefficient, k is more than or equal to 1 and is less than or equal to SNR, and SNR represents a signal-to-noise ratio.
8. The detection system of claim 6, wherein the determination module comprises:
the first determining submodule is used for determining that the pulse signal meeting the triggering condition is an external interference signal if the sensor which acquires the pulse signal meeting the triggering condition is a noise sensor;
and the second determining submodule is used for determining that the pulse signal meeting the triggering condition is an intermittent partial discharge signal in the electrical equipment if the sensor which acquires the pulse signal meeting the triggering condition is an ultrahigh frequency sensor.
9. The detection system of claim 6, wherein the determination module further comprises:
the judging submodule is used for judging whether the pulse signals which meet the triggering conditions and are acquired by the ultrahigh frequency sensor and the noise sensor are the same or not if the sensors which acquire the pulse signals which meet the triggering conditions comprise the ultrahigh frequency sensor and the noise sensor;
a third determining submodule, configured to determine that the pulse signal meeting the trigger condition acquired by the ultrahigh-frequency sensor is an intermittent partial discharge signal inside the electrical device if features of pulse sequence phase characteristic maps of the pulse signal meeting the trigger condition acquired by the ultrahigh-frequency sensor and the pulse signal meeting the trigger condition acquired by the noise sensor are different;
the comparison submodule is used for comparing the pulse amplitude of the pulse signal meeting the trigger condition acquired by the ultrahigh frequency sensor with the pulse amplitude of the pulse signal meeting the trigger condition acquired by the noise sensor if the pulse signal meeting the trigger condition acquired by the ultrahigh frequency sensor and the pulse sequence phase characteristic spectrum meeting the trigger condition acquired by the noise sensor have the same characteristics;
a fourth determining submodule, configured to determine that the pulse signal meeting the trigger condition acquired by the ultrahigh frequency sensor is an intermittent partial discharge signal inside the electrical device if the pulse amplitude of the pulse signal meeting the trigger condition acquired by the ultrahigh frequency sensor is not smaller than the pulse amplitude of the pulse signal meeting the trigger condition acquired by the noise sensor;
and a fifth determining submodule, configured to determine that the pulse signal meeting the trigger condition and acquired by the ultrahigh frequency sensor is an external interference signal if the pulse amplitude of the pulse signal meeting the trigger condition and acquired by the ultrahigh frequency sensor is smaller than the pulse amplitude of the pulse signal meeting the trigger condition and acquired by the noise sensor.
10. The detection system of claim 6, wherein the sampling module comprises:
the dividing submodule is used for dividing the point number of the pulse signal acquired each time into a plurality of intervals according to the sampling ratio of the pulse sequence phase characteristic spectrum, wherein the interval number is the point number/sampling ratio of the pulse signal;
and the sampling sub-module is used for sampling the point with the maximum pulse amplitude of the pulse signal in each interval as the sampling of the pulse sequence phase characteristic map.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1661384A (en) * | 2004-10-09 | 2005-08-31 | 西安交通大学 | Device for testing electric pulse strength for insulation |
| CN200941113Y (en) * | 2006-06-27 | 2007-08-29 | 南阳防爆集团有限公司 | Multipurpose pulse voltage tester |
| JP2007232495A (en) * | 2006-02-28 | 2007-09-13 | Mitsubishi Electric Corp | Partial discharge remote monitoring device |
| CN105223476A (en) * | 2015-09-16 | 2016-01-06 | 北京芯同汇科技有限公司 | A kind of fault arc detection method based on high-frequency characteristic and device |
| CN108919068A (en) * | 2018-06-07 | 2018-11-30 | 国网宁夏电力有限公司电力科学研究院 | Power equipment intermittent defect signal recognition method |
| KR102007287B1 (en) * | 2018-05-09 | 2019-08-06 | 한국전력공사 | Method and device for detecting partial discharge signal of stand alone type underground cable |
-
2019
- 2019-12-04 CN CN201911229443.7A patent/CN110988624B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1661384A (en) * | 2004-10-09 | 2005-08-31 | 西安交通大学 | Device for testing electric pulse strength for insulation |
| JP2007232495A (en) * | 2006-02-28 | 2007-09-13 | Mitsubishi Electric Corp | Partial discharge remote monitoring device |
| CN200941113Y (en) * | 2006-06-27 | 2007-08-29 | 南阳防爆集团有限公司 | Multipurpose pulse voltage tester |
| CN105223476A (en) * | 2015-09-16 | 2016-01-06 | 北京芯同汇科技有限公司 | A kind of fault arc detection method based on high-frequency characteristic and device |
| KR102007287B1 (en) * | 2018-05-09 | 2019-08-06 | 한국전력공사 | Method and device for detecting partial discharge signal of stand alone type underground cable |
| CN108919068A (en) * | 2018-06-07 | 2018-11-30 | 国网宁夏电力有限公司电力科学研究院 | Power equipment intermittent defect signal recognition method |
Non-Patent Citations (2)
| Title |
|---|
| 基于高灵敏测量的GIS绝缘子表面微金属颗粒局部放电特性;许渊 等;《高电压技术》;20190930;第45卷(第9期);正文2707至2714页 * |
| 粒子群优化算法在电气设备特高频局部放电源定位中的应用;牛勃 等;《智慧电力》;20180930;第48卷(第9期);正文第95至100页 * |
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