Ground fault positioning device and method for 35KV line

Abstract

The invention discloses a grounding fault positioning device for a 35KV line. The grounding fault positioning device comprises a host and a fault positioning module, the host is used for generating a test signal and injecting the test signal into a fault line to be tested; and the fault positioning module is used for receiving a reflection signal returned by the fault line based on the test signal, and performing fault positioning according to the reflection signal to determine a fault point. Through cooperative work of the host and the fault positioning module, the host generates a test signal and injects the test signal into a to-be-detected fault line, more effective detection can be carried out for different types of grounding faults, the fault positioning module can rapidly receive a reflected signal and carry out fault positioning, the position of a fault point is determined in time, and the fault detection efficiency is improved. And operation and maintenance personnel can quickly take measures for maintenance according to the positioning result, so that the fault processing time is shortened, the power failure time is reduced, and the power supply reliability of the power system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fault location, and in particular to a ground fault location device and method for a 35KV line. Background Art

[0002] 35kV transmission lines are the critical link connecting substations in the power system. As the primary voltage level of substations, their stable operation directly supports the power supply reliability of the regional power grid. In actual operation, due to various factors such as environmental factors and equipment aging, transmission lines may suffer ground faults. Ground faults not only cause line tripping and affect power supply quality, but also pose a threat to the safety of equipment and personnel. Therefore, timely and accurate location of ground faults is crucial for quickly restoring power and reducing losses caused by failures.

[0003] Traditional ground fault location methods, such as the impedance method and the traveling wave method, can locate the fault position to a certain extent, but they have disadvantages such as low positioning accuracy, complex operation, and poor equipment portability, which makes it difficult to meet the needs of fast and accurate on-site positioning. Summary of the Invention

[0004] The embodiment of the present invention provides a ground fault location device for a 35KV line, which can improve the fault location accuracy and field adaptability in complex lines, meet the needs of fast and accurate positioning, and ensure the safety and reliability of the power system.

[0005] In a first aspect, an embodiment of the present invention provides a ground fault locating device for a 35KV line, comprising a host and a fault locating module;

[0006] The host is used to generate a test signal and inject the test signal into the fault line to be tested;

[0007] The fault location module is used to receive a reflected signal returned by the fault line based on the test signal, and perform fault location according to the reflected signal to determine the fault point.

[0008] Furthermore, the host includes a lithium battery pack, a power conversion module, a signal processing module, a signal output module and a signal injection module;

[0009] The power conversion module is used to convert the DC power of the lithium battery pack into an AC signal of a specific frequency;

[0010] The signal processing module performs voltage boosting processing on the AC signal to obtain a high-voltage signal;

[0011] The signal output module performs signal conversion on the high-voltage signal and outputs a test signal suitable for detecting a ground fault, wherein the test signal includes a high-voltage AC signal and a high-voltage DC signal;

[0012] The signal injection module is used to inject the test signal into the fault line to be tested.

[0013] Furthermore, the signal processing module includes a voltage boost module and a voltage doubling module;

[0014] The boost module uses a low-frequency transformer to boost the AC signal output by the power conversion module to 6000V;

[0015] The voltage doubling module uses a voltage doubling circuit to boost the AC signal output by the power conversion module to 5000V.

[0016] Furthermore, the signal output module includes an AC output module and a DC output module;

[0017] The AC output module is used to convert the AC signal output by the boost module so that the output voltage after conversion is close to the 35KV line voltage, and output the converted high-voltage AC signal;

[0018] The DC output module is used to perform DC conversion on the AC signal output by the voltage doubling module and output the converted high-voltage DC signal.

[0019] Furthermore, the fault location module includes a reflection signal receiving unit, a reflection signal processing unit, a fault signal determination unit and a fault location unit;

[0020] The reflected signal receiving unit is used to receive the reflected signal returned by the fault line based on the test signal;

[0021] The reflection signal processing unit is used to perform signal processing on the received reflection signal to extract the reflection signal characteristics;

[0022] The fault signal determination unit compares the reflection signal characteristics with the test signal characteristics of the test signal, and determines the reflection signal with the consistent comparison as a fault signal;

[0023] The fault location unit adopts a fault location algorithm to calculate the specific location of the fault point according to the fault signal.

[0024] Furthermore, the fault location module is also used to store fault information and transmit the fault information to a remote monitoring center via wireless means.

[0025] Furthermore, the device also includes dual liquid crystal display screens, including a first display screen of the host and a second display screen of the fault location module, for displaying device status, signal parameters and fault location results.

[0026] In a second aspect, an embodiment of the present invention provides a ground fault location method for a 35 kV line. The ground fault location device for a 35 kV line described in any one of the first aspects is used to implement the specific method of ground fault location as follows:

[0027] After a ground fault occurs, a pre-processed test signal is injected into the fault line;

[0028] receiving a reflected signal returned by the fault line based on the test signal;

[0029] The fault location is performed based on the reflected signal to determine the fault point.

[0030] Furthermore, injecting a pre-processed test signal into the fault line includes:

[0031] Convert the DC power of the lithium battery pack built into the device into an AC signal of a specific frequency;

[0032] performing voltage boosting processing on the AC signal to obtain a high-voltage signal;

[0033] Performing signal conversion on the high-voltage signal to output a test signal suitable for detecting a ground fault, wherein the test signal includes a high-voltage AC signal and a high-voltage DC signal;

[0034] The test signal is injected into the fault line to be tested.

[0035] Furthermore, the performing fault location and determining the fault point according to the reflected signal includes:

[0036] Performing signal processing on the received reflected signal to extract the reflected signal features;

[0037] Comparing the reflection signal characteristics with the test signal characteristics of the test signal, and determining the reflection signal with the consistent comparison as a fault signal;

[0038] A fault location algorithm is used to calculate the specific location of the fault point based on the fault signal.

[0039] Compared with the prior art, the embodiments of the present invention provide a ground fault location device and method for a 35KV line, which have the following beneficial effects: through the coordinated operation of the host and the fault location module, the host generates a test signal and injects it into the fault line to be tested, which can more effectively detect different types of ground faults. The fault location module can quickly receive the reflected signal and locate the fault, and promptly determine the location of the fault point. Operation and maintenance personnel can quickly take repair measures based on the location results, shortening the fault handling time, thereby reducing the power outage time and improving the power supply reliability of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical features of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 This is a first structural diagram of an embodiment of a ground fault locating device for a 35KV line provided by the present invention;

[0042] Figure 2 This is a second structural diagram of an embodiment of a ground fault locating device for a 35KV line provided by the present invention;

[0043] Figure 3 The present invention provides a flow chart of an embodiment of a ground fault location method for a 35KV line. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] It should be noted that although the device schematics illustrate functional module divisions and the flowcharts illustrate logical sequences, in certain circumstances, the steps shown or described may be performed in a sequence that differs from the module divisions in the device or the sequence in the flowcharts. The terms "first," "second," and so on, in the specification, claims, and drawings, are used to distinguish similar items and are not necessarily used to describe a specific sequence or precedence.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used herein are for the purpose of describing embodiments of the present invention only and are not intended to limit the present invention.

[0047] First, see Figure 1 As shown, an embodiment of the present invention provides a ground fault location device for a 35KV line, comprising a host and a fault location module;

[0048] The host is used to generate a test signal and inject the test signal into the fault line to be tested;

[0049] The fault location module is used to receive a reflected signal returned by the fault line based on the test signal, and perform fault location according to the reflected signal to determine the fault point.

[0050] Specifically, the ground fault location device consists of two parts: a host and a fault location module. They work together to achieve the fault location function. The host is the core part of the entire device, responsible for signal generation, injection, and communication with the fault location module. The fault location module is installed near the key nodes of the line or suspected fault points, and is used to receive the reflected signal returned by the fault line based on the test signal. By processing and analyzing the reflected signal, the specific location of the fault point can be determined.

[0051] The ground fault locating device of the present invention works in coordination with a host computer and a fault locating module. The host computer generates a test signal and injects it into the fault line to be tested, thereby more effectively detecting different types of ground faults. The fault locating module can quickly receive the reflected signal and locate the fault, promptly determining the location of the fault point. Operation and maintenance personnel can quickly take repair measures based on the positioning results, shortening the fault handling time, thereby reducing the power outage time and improving the power supply reliability of the power system.

[0052] In an optional embodiment, the host includes a lithium battery pack, a power conversion module, a signal processing module, a signal output module and a signal injection module;

[0053] The power conversion module is used to convert the DC power of the lithium battery pack into an AC signal of a specific frequency;

[0054] The signal processing module performs voltage boosting processing on the AC signal to obtain a high-voltage signal;

[0055] The signal output module performs signal conversion on the high-voltage signal and outputs a test signal suitable for detecting a ground fault, wherein the test signal includes a high-voltage AC signal and a high-voltage DC signal;

[0056] The signal injection module is used to inject the test signal into the fault line to be tested.

[0057] For example, see Figure 2As shown, the device has a built-in lithium battery pack, which serves as a power supply unit and can provide a stable DC power supply. The power conversion module converts the DC power output by the lithium battery pack into a low-frequency AC signal of a specific frequency. The signal power is about 100W and the voltage output is 220V. The signal processing module boosts the AC signal output by the power conversion module to obtain a high-voltage signal. The signal output module further converts the high-voltage signal according to the detection requirements and outputs a test signal suitable for detecting ground faults, including a high-voltage AC signal and a high-voltage DC signal. The signal injection module injects the test signal generated by the signal output module into the fault line to be tested.

[0058] The ground fault locating device of the present invention adopts a portable structural design and is powered by a built-in lithium battery pack, requiring no external power supply. The device is small in size and light in weight, making it easy to carry and transport. Through precise signal processing and boosting technology, the strength and accuracy of the test signal are ensured, and it can output both high-voltage AC and high-voltage DC test signals to meet different detection needs.

[0059] In an optional embodiment, the signal processing module includes a voltage boost module and a voltage doubling module;

[0060] The boost module uses a low-frequency transformer to boost the AC signal output by the power conversion module to 6000V;

[0061] The voltage doubling module uses a voltage doubling circuit to boost the AC signal output by the power conversion module to 5000V.

[0062] For example, see Figure 2 As shown, the signal processing module includes a boost module and a voltage doubling module. The boost module adopts a low-frequency transformer and uses the principle of electromagnetic induction to increase the voltage by changing the turns ratio of the primary coil and the secondary coil. It boosts the AC signal output by the power conversion module to 6000V, providing a suitable high-voltage AC signal foundation for subsequent test signals.

[0063] The voltage doubling module uses a voltage doubling circuit, which is usually composed of a diode and a capacitor. It uses the unidirectional conductivity of the diode and the energy storage characteristics of the capacitor to superimpose the peak voltage of the AC signal, thereby doubling the voltage. The specific frequency signal output by the power conversion module is passed through the voltage doubling circuit to achieve a voltage of 5000V, providing another high-voltage signal form for the test signal.

[0064] It is understandable that in a 35kV line, a ground fault may occur at a location that is far away or where insulation damage is more severe. The boost module boosts the AC signal to 6000V, and the voltage doubler module boosts the signal to 5000V. Such a high voltage can generate a test signal of sufficient strength, so that it can still maintain sufficient energy during long-distance transmission, ensuring that the signal can reach every corner of the line and effectively detect potential ground fault points. For example, on a long 35kV overhead line, if there is no sufficiently high test voltage, the signal may be severely attenuated during transmission and cannot accurately reflect the actual situation of the line. The boost and voltage doubler modules solve this problem.

[0065] In an optional embodiment, the signal output module includes an AC output module and a DC output module;

[0066] The AC output module is used to convert the AC signal output by the boost module so that the output voltage after conversion is close to the 35KV line voltage, and output the converted high-voltage AC signal;

[0067] The DC output module is used to perform DC conversion on the AC signal output by the voltage doubling module and output the converted high-voltage DC signal.

[0068] For example, see Figure 2 As shown in the figure, the 35kV line has its own specific voltage level. The AC output module converts the 6000V AC signal output by the boost module to make the output voltage close to the 35kV line voltage. This voltage matching ensures that the test signal is consistent with the actual operating environment of the line when it is transmitted in the 35kV line. The AC signal close to the 35kV line voltage can be effectively transmitted over a wider line range, allowing the detection device to cover a longer line section. At the same time, the higher voltage signal can enhance the perception of minor faults in the line and improve the sensitivity of detection.

[0069] In 35KV line ground fault detection, DC signals have unique advantages. The DC output module converts the 5000V AC signal output by the voltage doubler module into DC and outputs a high-voltage DC signal, which can meet the detection requirements of parameters such as line insulation resistance and DC leakage current.

[0070] It can be understood that the AC output module and the DC output module output high-voltage AC signals and high-voltage DC signals respectively. These two signals have different characteristics and advantages in fault detection. The AC signal can detect the impedance change of the line, the reflection characteristics of the fault point, etc., while the DC signal can detect the insulation resistance of the line, DC leakage current, etc. By working together, comprehensive detection of 35KV line grounding faults can be achieved, improving the accuracy and reliability of fault detection.

[0071] In an optional embodiment, the fault location module includes a reflection signal receiving unit, a reflection signal processing unit, a fault signal determination unit and a fault location unit;

[0072] The reflected signal receiving unit is used to receive the reflected signal returned by the fault line based on the test signal;

[0073] The reflection signal processing unit is used to perform signal processing on the received reflection signal to extract the reflection signal characteristics;

[0074] The fault signal determination unit compares the reflection signal characteristics with the test signal characteristics of the test signal, and determines the reflection signal with the consistent comparison as a fault signal;

[0075] The fault location unit adopts a fault location algorithm to calculate the specific location of the fault point according to the fault signal.

[0076] Specifically, the test signal will generate a reflected signal at the fault point. The reflected signal receiving unit is used to receive the reflected signal. The unit has a signal sampling function and can discretize the received reflected signal to convert the continuous analog signal into a discrete digital signal. Through reasonable sampling frequency and sampling accuracy, it can be ensured that the sampled signal can completely retain the characteristic information of the original signal.

[0077] The reflected signal processing unit further processes the received reflected signal, including signal filtering, signal amplification, synchronous signal processing and A / D conversion. During the transmission of the reflected signal, it will be affected by various noises and interferences, such as electromagnetic interference, thermal noise, etc. The signal filtering function can effectively remove these noises and interferences, improve the signal-to-noise ratio of the signal, and make the signal clearer and purer. In addition, the reflected signal will be attenuated to a certain extent during the transmission process, and the signal strength may be weak when it reaches the receiving unit. The signal amplification function can amplify the weak reflected signal to make it reach the appropriate amplitude range, which is convenient for subsequent signal processing and analysis. Synchronous signal processing can process different types of reflected signals to ensure the accuracy and consistency of the signal. A / D conversion converts the analog signal into a digital signal, which is convenient for the computer to perform digital signal processing and analysis, and improve the accuracy and reliability of signal processing.

[0078] The fault signal determination unit compares the characteristics of the reflected signal with the test signal characteristics of the test signal. Through a strict matching algorithm, the reflected signal that is consistent with the comparison is determined as the fault signal. This comparison method can effectively eliminate the interference of non-fault signals and ensure the accurate identification of fault signals.

[0079] The fault location unit uses advanced fault location algorithms, such as wavelet transform and neural networks, to process and analyze fault signals. In 35kV lines, due to the complexity of the lines and the diversity of faults, relying solely on a single parameter for fault location is often not accurate enough. The fault location algorithm compares parameters such as the time difference and amplitude difference between the reflected signal and the injected signal, and comprehensively analyzes the relationship between these parameters and the fault point location to determine the specific location of the fault point. The comprehensive analysis of multiple parameters can reduce the error caused by a single parameter and improve the accuracy of fault location.

[0080] It is understandable that advanced fault location algorithms and efficient computing power enable the fault location unit to quickly calculate the specific location of the fault point. Operation and maintenance personnel can quickly reach the fault site for repairs based on the location results, shortening the fault handling time and improving the operational reliability of the power system.

[0081] In an optional implementation, the fault location module is further configured to store fault information and transmit the fault information to a remote monitoring center via wireless means.

[0082] Specifically, the fault location module also has the function of data storage, which can save the processed fault information to form a historical fault database. Through the long-term accumulation and analysis of historical data, it can gain in-depth understanding of the fault occurrence patterns, fault type distribution, and high-incidence areas of 35KV lines under different operating conditions. When the line fails again, the stored fault information can serve as an important reference to help operation and maintenance personnel quickly trace the cause of the fault and improve the efficiency of fault handling.

[0083] By wirelessly transmitting fault information to the remote monitoring center, real-time remote monitoring of 35KV line grounding faults can be achieved. Operation and maintenance personnel can obtain fault information in a timely manner without having to visit the site, understand the operating status of the line, and improve the efficiency and effectiveness of fault handling.

[0084] In an optional embodiment, the device further includes dual liquid crystal display screens, including a first display screen of the host and a second display screen of the fault location module, for displaying device status, signal parameters and fault location results.

[0085] Specifically, the device of the present invention also includes a dual LCD display, including a first display of the host and a second display of the fault location module. The first display can display the overall operating status of the equipment, key signal parameters and some basic system setting information. The operator can quickly confirm whether the host is operating normally and whether the various parameters are set correctly through the first display, laying the foundation for subsequent fault detection and positioning work. The second display of the fault location module focuses on displaying information related to fault location, such as the characteristic parameters of the reflected signal, the determination results of the fault signal and the final fault location results. The operator can go directly to the fault point for maintenance according to the display results, which greatly improves the efficiency of fault handling.

[0086] The dual LCD display design allows operators to obtain relevant information from the host and fault location module at the same time without having to frequently switch between different interfaces or devices. The human-computer interaction interface can provide real-time feedback on the equipment's operating status and operation results, allowing operators to promptly understand whether the equipment operation is successful and the progress of fault location. At the same time, operators can also perform some simple interactive operations through the interface, such as adjusting signal parameters and viewing historical data.

[0087] Second, see Figure 2 As shown, an embodiment of the present invention further provides a ground fault location method for a 35KV line, comprising:

[0088] S1: After a ground fault occurs, a pre-processed test signal is injected into the fault line;

[0089] S2: receiving a reflected signal returned by the fault line based on the test signal;

[0090] S3: Perform fault location according to the reflected signal to determine the fault point.

[0091] In an optional implementation manner, injecting a pre-processed test signal into the fault line includes:

[0092] Convert the DC power of the lithium battery pack built into the device into an AC signal of a specific frequency;

[0093] performing voltage boosting processing on the AC signal to obtain a high-voltage signal;

[0094] Performing signal conversion on the high-voltage signal to output a test signal suitable for detecting a ground fault, wherein the test signal includes a high-voltage AC signal and a high-voltage DC signal;

[0095] The test signal is injected into the fault line to be tested.

[0096] In an optional implementation, the performing fault location and determining the fault point according to the reflected signal includes:

[0097] Performing signal processing on the received reflected signal to extract the reflected signal features;

[0098] Comparing the reflection signal characteristics with the test signal characteristics of the test signal, and determining the reflection signal with the consistent comparison as a fault signal;

[0099] A fault location algorithm is used to calculate the specific location of the fault point based on the fault signal.

[0100] It should be noted that the ground fault locating method for a 35KV line provided in an embodiment of the present invention can implement all the processes of the various modules of the ground fault locating device for a 35KV line described in any of the above embodiments. The functions and technical effects of the ground fault locating method for a 35KV line described in the above embodiments correspond to the functions and technical effects of the various modules and units in the device, and are not repeated here.

[0101] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. It should be pointed out that for those skilled in the art, several equivalent obvious variations and / or equivalent replacements can be made without departing from the technical principles of the present invention. These obvious variations and / or equivalent replacements should also be regarded as the scope of protection of the present invention.

Claims

1. A ground fault location device for a 35KV line, characterized in that: Including host and fault location module; The host is used to generate a test signal and inject the test signal into the fault line to be tested; The fault location module is used to receive a reflected signal returned by the fault line based on the test signal, and perform fault location according to the reflected signal to determine the fault point.

2. The ground fault location device for a 35KV line according to claim 1, characterized in that: The host includes a lithium battery pack, a power conversion module, a signal processing module, a signal output module and a signal injection module; The power conversion module is used to convert the DC power of the lithium battery pack into an AC signal of a specific frequency; The signal processing module performs voltage boosting processing on the AC signal to obtain a high-voltage signal; The signal output module performs signal conversion on the high-voltage signal and outputs a test signal suitable for detecting a ground fault, wherein the test signal includes a high-voltage AC signal and a high-voltage DC signal; The signal injection module is used to inject the test signal into the fault line to be tested.

3. The ground fault location device for a 35KV line according to claim 2, characterized in that: The signal processing module includes a voltage boost module and a voltage doubling module; The boost module uses a low-frequency transformer to boost the AC signal output by the power conversion module to 6000V; The voltage doubling module uses a voltage doubling circuit to boost the AC signal output by the power conversion module to 5000V.

4. The ground fault location device for a 35KV line according to claim 2, characterized in that: The signal output module includes an AC output module and a DC output module; The AC output module is used to convert the AC signal output by the boost module so that the output voltage after conversion is close to the 35KV line voltage, and output the converted high-voltage AC signal; The DC output module is used to perform DC conversion on the AC signal output by the voltage doubling module and output the converted high-voltage DC signal.

5. The ground fault location device for a 35KV line according to claim 1, characterized in that: The fault location module includes a reflection signal receiving unit, a reflection signal processing unit, a fault signal determination unit and a fault location unit; The reflected signal receiving unit is used to receive the reflected signal returned by the fault line based on the test signal; The reflection signal processing unit is used to perform signal processing on the received reflection signal to extract the reflection signal characteristics; The fault signal determination unit compares the reflection signal characteristics with the test signal characteristics of the test signal, and determines the reflection signal with the consistent comparison as a fault signal; The fault location unit adopts a fault location algorithm to calculate the specific location of the fault point according to the fault signal.

6. The ground fault location device for a 35KV line according to claim 1, characterized in that: The fault location module is further used to store fault information and transmit the fault information to a remote monitoring center via wireless means.

7. The ground fault location device for a 35KV line according to claim 1, characterized in that: The device also includes dual liquid crystal display screens, including a first display screen of the host and a second display screen of the fault location module, for displaying device status, signal parameters and fault location results.

8. A ground fault location method for a 35KV line, characterized in that: The specific method for locating a ground fault using the ground fault location device for a 35KV line according to any one of claims 1 to 7 is as follows: After a ground fault occurs, a pre-processed test signal is injected into the fault line; receiving a reflected signal returned by the fault line based on the test signal; The fault location is performed based on the reflected signal to determine the fault point.

9. The ground fault location method for a 35KV line according to claim 8, characterized in that: The injecting a pre-processed test signal into the fault line comprises: Convert the DC power of the lithium battery pack built into the device into an AC signal of a specific frequency; performing voltage boosting processing on the AC signal to obtain a high-voltage signal; Performing signal conversion on the high-voltage signal to output a test signal suitable for detecting a ground fault, wherein the test signal includes a high-voltage AC signal and a high-voltage DC signal; The test signal is injected into the fault line to be tested.

10. The ground fault location method for a 35KV line according to claim 8, characterized in that: The performing fault location and determining the fault point according to the reflected signal includes: Performing signal processing on the received reflected signal to extract the reflected signal features; Comparing the reflection signal characteristics with the test signal characteristics of the test signal, and determining the reflection signal with the consistent comparison as a fault signal; A fault location algorithm is used to calculate the specific location of the fault point based on the fault signal.

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