Anti-interference identification and positioning system for early fault of distribution line

Abstract

The invention discloses a distribution line early fault anti-interference identification and positioning system, which relates to the technical field of power system fault monitoring points and comprises a signal acquisition module, a signal extraction module, an early fault analysis module and an early fault positioning module. The signal acquisition module is used for acquiring circuit signals through a sensor and recording sensor information, and the circuit signals comprise electrical information and non-electrical information; the signal extraction module is used for acquiring an electrical waveform according to the circuit signal, and performing wavelet decomposition on the electrical waveform by using wavelet transform to acquire a feature vector; the influence of non-electrical information on electrical information is fully considered, so that the early fault type identification capability under the influence of the non-electrical information is improved, the anti-interference capability is enhanced, the early fault position can be positioned, the early fault can be found and processed in time, the distribution line is kept in a good operation state, and the power distribution efficiency is improved. And power failure caused by faults is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of power system fault monitoring points, and particularly to an anti-interference identification and location system for early faults in distribution lines. Background Art

[0002] Distribution lines are an important part of the power system, and their operating status is directly related to the reliability and stability of power supply. However, during long-term operation, distribution lines are prone to various faults due to the influence of natural environment, equipment aging, external force damage and other factors. Timely detection and accurate location of faults are of great significance for reducing power outage time and economic losses.

[0003] Currently, the methods for monitoring distribution line fault points mainly include methods based on current and voltage mutations, methods based on traveling waves, and methods based on partial discharges, etc. However, these methods have certain limitations in practical applications. The method for monitoring faults based on current and voltage mutation signals has low sensitivity to faults and is difficult to detect early faults; the method for monitoring faults based on traveling wave signals can quickly locate faults, but is easily affected by changes in line distribution parameters and noise interference; the method for monitoring faults based on partial discharges can detect faults such as insulation aging, but is easily affected by on-site electromagnetic interference and has poor anti-interference ability. Summary of the Invention

[0004] The technical problem solved by the present invention is that in the related art, the method for monitoring faults using current and voltage mutation signals has low sensitivity to faults and is difficult to detect early faults; the method for monitoring faults based on traveling wave signals can quickly locate faults, but is easily affected by changes in line distribution parameters and noise interference; the method for monitoring faults based on partial discharges can detect faults such as insulation aging, but is easily affected by on-site electromagnetic interference and has poor anti-interference ability.

[0005] To solve the above technical problem, the present invention provides the following technical solution: an anti-interference identification and location system for early faults in distribution lines, including a signal acquisition module, a signal extraction module, an early fault analysis module, and an early fault location module; The signal acquisition module is used to collect circuit signals through sensors and record sensor information, and the circuit signals include electrical information and non-electrical information; The signal extraction module is used to obtain electrical waveforms according to the circuit signals, and perform wavelet decomposition on the electrical waveforms using wavelet transform to obtain feature vectors; The early fault analysis module is used to take the relationship between the feature vector and the early fault type as the first correspondence, and the relationship between the feature vector, the early fault type and the non-electrical information as the second correspondence. And according to the same early fault type features in the first correspondence and the second correspondence, the corresponding feature vectors are selected, the feature vector range is determined according to the corresponding feature vectors, and the feature vector range is used as the recognition interval to perform early fault recognition on the feature vectors obtained in real time; The early fault location module is used to locate the early fault location according to the sensor information and the electrical information.

[0006] As a preferred solution of the early fault anti-interference recognition and location system for distribution lines of the present invention, wherein: the electrical information includes current information and voltage information. The current information is collected by using a current sensor, and the number information and the location information of the current sensor are put into one-to-one correspondence with the current information. The voltage information is collected by using a voltage sensor, and the number information and the location information of the voltage sensor are put into one-to-one correspondence with the voltage information.

[0007] As a preferred solution of the early fault anti-interference recognition and location system for distribution lines of the present invention, wherein: the non-electrical information includes temperature information, vibration information and humidity information. The temperature information is collected by using a temperature sensor, and the number information and the location information of the temperature sensor are put into one-to-one correspondence with the temperature information. The vibration information is collected by using a vibration sensor, and the number information and the location information of the vibration sensor are put into one-to-one correspondence with the vibration information. The humidity information is collected by using a humidity sensor, and the number information and the location information of the humidity sensor are put into one-to-one correspondence with the humidity information.

[0008] As a preferred solution of the early fault anti-interference recognition and location system for distribution lines of the present invention, wherein: the early fault analysis module includes a waveform primitive unit, a feature extraction unit and an early fault type unit; The waveform primitive unit is used to obtain the current information and the voltage information, draw the current information and the voltage information into a waveform diagram, and obtain the electrical waveforms of the current information and the voltage information; The feature extraction unit uses wavelet transform to perform wavelet decomposition on the electrical waveforms of the current information and the voltage information respectively, obtains feature vectors, and groups the feature vectors corresponding to the current information and the voltage information; The early fault type unit is used to correspond the feature vectors of the current information and the voltage information corresponding to each early fault type.

[0009] As a preferred solution of the early fault anti-interference identification and location system for the distribution line described in the present invention, wherein: the feature vector includes mean value, standard deviation, root mean square, peak value, peak difference, skewness, kurtosis, impulse, waveform factor, margin factor, spectral mean value, spectral standard deviation, frequency centroid, root mean square frequency, spectral skewness and spectral kurtosis.

[0010] As a preferred solution of the early fault anti-interference identification and location system for the distribution line described in the present invention, wherein: the early fault types include distribution line insulation damage, transformer insulation aging, transformer overheating, poor switch contact, switch refusal to operate, switch malfunction and tree contact.

[0011] As a preferred solution of the early fault anti-interference identification and location system for the distribution line described in the present invention, wherein: the early fault analysis module respectively creates various early fault types at the fault point, collects and records the current information and voltage information corresponding to various early fault types closest to the fault point, extracts the feature vectors corresponding to the current information and voltage information, and establishes the relationship between the feature vectors and the early fault types as the first corresponding relationship.

[0012] As a preferred solution of the early fault anti-interference identification and location system for the distribution line described in the present invention, wherein: the early fault analysis module is used to record the temperature information, vibration information and humidity information corresponding to various early fault types closest to the fault point, perform a difference processing on the temperature information, vibration information and humidity information respectively with the temperature information, vibration information and humidity information before the occurrence of the early fault, calculate the change rates of the temperature information, vibration information and humidity information before and after the occurrence of the early fault, and establish the relationship between the feature vectors, the early fault types and the non-electrical information as the second corresponding relationship.

[0013] As a preferred solution of the early fault anti-interference identification and location system for the distribution line described in the present invention, wherein: according to the same early fault type features in the first corresponding relationship and the second corresponding relationship, the corresponding feature vectors are selected, and according to the corresponding feature vectors, the feature vector range is determined. The feature vector range is the numerical change range between the feature vectors when the temperature information, vibration information and humidity information are normal and the feature vectors when the temperature information, vibration information and humidity information are abnormal. The numerical change range is used as the feature vector range. If the numerical value of the feature vector corresponding to the collected current information and voltage information is within the feature vector range, it indicates that the collected current information and voltage information are within the identification interval and there is an early fault. According to the first corresponding relationship, the early fault type is obtained.

[0014] As a preferred solution of the early fault anti-interference identification and location system for the distribution line described in the present invention, specifically: compare the temperature information, vibration information, and humidity information collected by each sensor, obtain the position information and number information of the temperature sensors, vibration sensors, and humidity sensors that exceed the change rate in the temperature information, vibration information, and humidity information, and locate the early fault position according to the respective positions of the temperature sensors, vibration sensors, and humidity sensors with the change rate. The beneficial effects of the present invention: By taking the relationship between the eigenvector and the early fault type as the first corresponding relationship, and taking the relationship between the eigenvector, the early fault type, and the non-electrical information as the second corresponding relationship, and selecting the corresponding eigenvector according to the same early fault type characteristics in the first corresponding relationship and the second corresponding relationship, determining the eigenvector range according to the corresponding eigenvector, taking the eigenvector range as the identification interval, and performing early fault identification on the real-time obtained eigenvector, potential hidden dangers of the distribution line can be timely detected through the early fault monitoring points of the monitoring points, and the influence of non-electrical information on electrical information is fully considered, thereby improving the early fault type identification ability under the influence of non-electrical information and enhancing the anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 FIG. is a schematic diagram of the basic process of an early fault anti-interference identification and location system for a distribution line provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be made in conjunction with the accompanying drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments.

[0017] Embodiment 1, referring to Figure 1 , which is an embodiment of the present invention, provides an early fault anti-interference identification and location system for a distribution line, including a signal acquisition module, a signal extraction module, an early fault analysis module, and an early fault location module; The signal acquisition module is used to collect circuit signals through sensors and record sensor information. The circuit signals include electrical information and non-electrical information; The signal extraction module is used to obtain an electrical waveform according to the circuit signal and perform wavelet decomposition on the electrical waveform using wavelet transform to obtain an eigenvector; The early fault analysis module is used to take the relationship between the feature vector and the early fault type as the first correspondence relationship, and the relationship between the feature vector, the early fault type and the non - electrical information as the second correspondence relationship. And according to the same early fault type features in the first and second correspondence relationships, the corresponding feature vectors are selected. According to the corresponding feature vectors, the feature vector range is determined, and the feature vector range is used as the recognition interval to perform early fault recognition on the feature vectors obtained in real - time; The early fault location module is used to locate the early fault location according to the sensor information and the electrical information.

[0018] Preferably, in this embodiment, the relationship between the feature vector and the early fault type is taken as the first correspondence relationship, and the relationship between the feature vector, the early fault type and the non - electrical information is taken as the second correspondence relationship. And according to the same early fault type features in the first and second correspondence relationships, the corresponding feature vectors are selected. According to the corresponding feature vectors, the feature vector range is determined, and the feature vector range is used as the recognition interval to perform early fault recognition on the feature vectors obtained in real - time. By monitoring the early fault monitoring points of the monitoring points, potential hidden dangers of the distribution line can be found in time, repaired or replaced, avoiding the further expansion of the fault. Moreover, the early faults of the distribution line are relatively easy to repair, with less maintenance work, fewer parts to be replaced, and relatively low maintenance costs. And by detecting and dealing with the early faults in time, the distribution line can be kept in a good operating state, avoiding power outages caused by faults. And in this system, the influence of non - electrical information on electrical information is fully considered, so as to improve the ability to identify early fault types under the influence of non - electrical information, enhance the anti - interference ability, and can locate the early fault location, which is conducive to timely detecting and dealing with early faults, so that the distribution line can be kept in a good operating state and avoid power outages caused by faults.

[0019] Embodiment 2 is another embodiment of the present invention. The difference between this embodiment and the first embodiment is as follows.

[0020] The electrical information includes current information and voltage information. The current sensor is used to collect the current information, and the number information and position information of the current sensor are in one - to - one correspondence with the current information. The voltage sensor is used to collect the voltage information, and the number information and position information of the voltage sensor are in one - to - one correspondence with the voltage information.

[0021] Preferably, in this embodiment, electrical information monitoring points are set at intervals on the distribution line. Voltage sensors and current sensors are set at the monitoring points. The existing current sensors are used to collect the current information, and the existing voltage sensors are used to collect the voltage information, and the current information and voltage information at the monitoring points are sent to the signal extraction module.

[0022] Non-electrical information includes temperature information, vibration information, and humidity information. Temperature information is collected using a temperature sensor, and the serial number information and location information of the temperature sensor are corresponded to the temperature information one by one. Vibration information is collected using a vibration sensor, and the serial number information and location information of the vibration sensor are corresponded to the vibration information one by one. Humidity information is collected using a humidity sensor, and the serial number information and location information of the humidity sensor are corresponded to the humidity information one by one.

[0023] Preferably, in this embodiment, non-electrical information monitoring points are set at regular intervals on the distribution line. The spacing between non-electrical information monitoring points is smaller than that between electrical information monitoring points. That is, setting non-electrical information monitoring points more densely is beneficial to improving the accuracy of early fault location.

[0024] The early fault analysis module includes a waveform primitive unit, a feature extraction unit, and an early fault type unit. The waveform primitive unit is used to obtain current information and voltage information, and plot the current information and voltage information into a waveform diagram to obtain the electrical waveforms of the current information and voltage information. The feature extraction unit uses wavelet transform to perform wavelet decomposition on the electrical waveforms of the current information and voltage information respectively, obtains feature vectors, and groups the feature vectors corresponding to the current information and voltage information. The early fault type unit is used to correspond the feature vectors of the current information and voltage information corresponding to each early fault type.

[0025] The feature vectors include mean value, standard deviation, root mean square, peak value, peak difference, skewness, kurtosis, impulse, waveform factor, margin factor, spectral mean, spectral standard deviation, frequency centroid, root mean square frequency, spectral skewness, and spectral kurtosis. The root mean square value reflects the energy of the current information and voltage information; the peak value represents the maximum absolute value of the current information and voltage information; the peak difference represents the difference between the maximum value and the minimum value of the current information and voltage information; the skewness reflects the symmetry of the distribution of the current information and voltage information; the kurtosis reflects the sharpness of the distribution of the current information and voltage information; the impulse factor represents the ratio of the peak value to the mean value; the waveform factor represents the ratio of the RMS value to the absolute mean value; the margin factor represents the ratio of the peak value to the RMS value; the spectral mean reflects the average value of the spectrum; the spectral standard deviation reflects the degree of fluctuation of the spectrum; the frequency centroid reflects the centroid position of the spectrum; the root mean square frequency reflects the energy-weighted average frequency of the spectrum; the spectral skewness reflects the symmetry of the spectrum; the spectral kurtosis reflects the sharpness of the spectrum. Preferably, in this embodiment, wavelet transform is an analysis tool that can decompose a signal into different frequencies and time scales, and is very suitable for the analysis of electrical waveforms. The following is to decompose the electrical waveforms of current information and voltage information respectively by using wavelet transform to obtain electrical waveform primitives. It is necessary to select a suitable wavelet basis function, and the selection of the wavelet basis function is crucial for the decomposition effect. Commonly used basis functions include Daubechies db4, Haar, and Symlet. In this embodiment, discrete wavelet transform (DWT) is used to decompose the electrical waveform. Preferably, existing MATLAB and Python are used for decomposition, so as to obtain the electrical waveform primitives of current information and voltage information, and then the feature vectors of current information and voltage information are obtained by extracting the electrical waveform primitives of current information and voltage information through existing feature extraction techniques.

[0026] Early fault types include damaged distribution line insulation, aged transformer insulation, overheated transformer, poor switch contact, switch refusal to operate, switch malfunction, and tree contact.

[0027] The early fault analysis module includes creating various early fault types at the fault point respectively, collecting and recording the current information and voltage information corresponding to various early fault types closest to the fault point, extracting the feature vectors corresponding to the current information and voltage information, and establishing the relationship between the feature vectors and the early fault types as the first corresponding relationship.

[0028] Preferably, in this embodiment, various early fault types are artificially created at the fault point, such as damaged distribution line insulation, aged transformer insulation, overheated transformer, poor switch contact, switch refusal to operate, switch malfunction, and tree contact, and then the current information and voltage information under the early fault types are obtained, so as to establish the relationship between the feature vectors and the early fault types as the first corresponding relationship.

[0029] The early fault analysis module is used to record the temperature information, vibration information, and humidity information corresponding to various early fault types closest to the fault point, perform a difference operation on the temperature information, vibration information, and humidity information respectively with the temperature information, vibration information, and humidity information before the early fault occurs, calculate the change rates of the temperature information, vibration information, and humidity information before and after the early fault occurs, and establish the relationship between the feature vectors, early fault types, and non-electrical information as the second corresponding relationship.

[0030] According to the same early fault type characteristics in the first correspondence and the second correspondence, select the corresponding feature vectors, determine the feature vector range based on the corresponding feature vectors. The feature vector range is the numerical change range between the feature vectors when the temperature information, vibration information, and humidity information are normal and the feature vectors when the temperature information, vibration information, and humidity information are abnormal. Take the numerical change range as the feature vector range. If the numerical values of the feature vectors corresponding to the collected current information and voltage information are within the feature vector range, it indicates that the collected current information and voltage information are within the identification interval and there is an early fault. According to the first correspondence, obtain the early fault type.

[0031] Preferably in this embodiment, according to the same early fault type characteristics in the first correspondence and the second correspondence, select the corresponding feature vectors, determine the feature vector range based on the corresponding feature vectors, and take the feature vector range as the identification interval to perform early fault identification on the feature vectors obtained in real time. Timely discover potential hidden dangers in the distribution line through the early fault monitoring points of the monitoring points, and fully consider the influence of non-electrical information on electrical information, thereby improving the early fault type identification ability under the influence of non-electrical information and enhancing the anti-interference ability.

[0032] Compare the temperature information, vibration information, and humidity information collected by each sensor, obtain the position information and number information of the temperature sensors, vibration sensors, and humidity sensors that exceed the change rate in the temperature information, vibration information, and humidity information, and locate the early fault position according to the respective positions of the temperature sensors, vibration sensors, and humidity sensors with the change rate.

[0033] Preferably in this embodiment, compare the temperature information, vibration information, and humidity information, obtain the position information and number information of the temperature sensors, vibration sensors, and humidity sensors that exceed the change rate in the temperature information, vibration information, and humidity information, and according to the respective positions of the temperature sensors, vibration sensors, and humidity sensors with the change rate, it is possible to locate the early fault position, which is beneficial to timely discover and handle early faults, so that the distribution line maintains a good operating state and avoids power outages caused by faults.

[0034] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code. Among them, the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured article including an instruction device, and the instruction device implements the functions specified in one process Figure 1 one process or multiple processes and / or boxes Figure 1 the functions specified in one box or multiple boxes.

[0035] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. An anti-interference identification and positioning system for early faults in distribution lines, characterized in that, It includes a signal acquisition module, a signal extraction module, an early fault analysis module, and an early fault location module; The signal acquisition module is used to collect circuit signals through sensors and record sensor information. The circuit signals include electrical information and non-electrical information; The signal extraction module is used to obtain electrical waveforms based on the circuit signals and perform wavelet decomposition on the electrical waveforms using wavelet transform to obtain feature vectors; The early fault analysis module uses the relationship between the feature vectors and early fault types as the first correspondence relationship, and the relationship between the feature vectors, early fault types, and non-electrical information as the second correspondence relationship. And according to the same early fault type characteristics in the first correspondence relationship and the second correspondence relationship, select the corresponding feature vectors, determine the feature vector range based on the corresponding feature vectors, and use the feature vector range as the recognition interval to perform early fault recognition on the feature vectors obtained in real time; The early fault location module is used to locate the early fault location according to the sensor information and electrical information.

2. The anti-interference identification and location system for early faults of a power distribution line according to claim 1, characterized in that: The electrical information includes current information and voltage information. A current sensor is used to collect current information, and the number information and location information of the current sensor are in one-to-one correspondence with the current information. A voltage sensor is used to collect voltage information, and the number information and location information of the voltage sensor are in one-to-one correspondence with the voltage information.

3. The anti-interference identification and location system for early faults of a power distribution line according to claim 1, characterized in that: The non-electrical information includes temperature information, vibration information, and humidity information. A temperature sensor is used to collect temperature information, and the number information and location information of the temperature sensor are in one-to-one correspondence with the temperature information. A vibration sensor is used to collect vibration information, and the number information and location information of the vibration sensor are in one-to-one correspondence with the vibration information. A humidity sensor is used to collect humidity information, and the number information and location information of the humidity sensor are in one-to-one correspondence with the humidity information.

4. A distribution line early fault anti-interference identification and positioning system according to claim 2 or 3, characterized in that: The early fault analysis module includes a waveform primitive unit, a feature extraction unit, and an early fault type unit; The waveform primitive unit is used to obtain current information and voltage information, and plot the current information and voltage information into a waveform diagram to obtain the electrical waveforms of the current information and voltage information; The feature extraction unit uses wavelet transform to perform wavelet decomposition on the electrical waveforms of the current information and voltage information respectively to obtain feature vectors, and groups the feature vectors corresponding to the current information and voltage information; The early fault type unit is used to correspond the feature vectors of the current information and voltage information corresponding to each early fault type.

5. An early fault anti-interference identification and positioning system for a distribution line according to claim 4, characterized in that: The feature vectors include mean value, standard deviation, root mean square, peak value, peak-to-peak value, skewness, kurtosis, impulse, waveform factor, margin factor, spectral mean value, spectral standard deviation, frequency centroid, root mean square frequency, spectral skewness, and spectral kurtosis.

6. The anti-interference identification and location system for early faults of a distribution line according to claim 5, characterized in that: The early fault types include distribution line insulation damage, transformer insulation aging, transformer overheating, switch contact failure, switch refusal to operate, switch misoperation, and tree contact.

7. The anti-interference identification and positioning system for early faults of a distribution line according to claim 6, characterized in that: The early fault analysis module includes creating various early fault types at the fault point respectively, collecting and recording the current information and voltage information corresponding to various early fault types closest to the fault point, extracting the feature vectors corresponding to the current information and voltage information, and establishing the relationship between the feature vectors and the early fault types as the first correspondence.

8. The anti-interference identification and location system for early faults of a distribution line according to claim 7, characterized in that: The early fault analysis module is used to record the temperature information, vibration information, and humidity information corresponding to various early fault types closest to the fault point, perform a difference processing on the temperature information, vibration information, and humidity information respectively with the temperature information, vibration information, and humidity information before the occurrence of the early fault, calculate the change rates of the temperature information, vibration information, and humidity information before and after the occurrence of the early fault, and establish the relationship between the feature vectors, early fault types, and non-electrical information as the second correspondence.

9. A distribution line early fault anti-interference identification and positioning system according to claim 8, characterized in that: According to the same early fault type features in the first correspondence and the second correspondence, select the corresponding feature vectors, determine the feature vector range based on the corresponding feature vectors. The feature vector range is the numerical change range between the feature vectors when the temperature information, vibration information, and humidity information are normal and the feature vectors when the temperature information, vibration information, and humidity information are abnormal. Take the numerical change range as the feature vector range. If the numerical value of the feature vector corresponding to the collected current information and voltage information is within the feature vector range, it indicates that the collected current information and voltage information are in the identification interval and there is an early fault. According to the first correspondence, obtain the early fault type.

10. A distribution line early fault anti-interference identification and positioning system as described in claim 9, characterized in that: Compare the temperature information, vibration information, and humidity information collected by each sensor, obtain the position information and number information of the temperature sensors, vibration sensors, and humidity sensors whose temperature information, vibration information, and humidity information exceed the change rate, and locate the early fault position according to the respective positions of the temperature sensors, vibration sensors, and humidity sensors with the change rate.

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