Ground fault detection system for ten-thousand-volt power distribution network

Abstract

The invention provides a ten-thousand-volt power distribution network ground fault detection system comprising a single-phase circuit information acquisition module used for acquiring current information, voltage information and impedance information of any phase circuit in a power distribution network; the single-phase circuit information calculation module is used for calculating single-phase circuit operation information according to a judgment formula; and the fault information judgment module is used for judging a fault line according to the fault information to obtain fault point information, and outputting the fault information if an error value between the single-phase circuit operation information of any phase circuit in the power distribution network and the single-phase circuit operation information of other two-phase circuits exceeds a judgment threshold value. Therefore, according to the method, the current, the voltage and the impedance of any single-phase line in the power distribution network are subjected to set operation, whether the line has the fault or not is quickly determined according to the relation between the operation result and the judgment threshold value, and the troubleshooting efficiency of the power distribution network is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of power system fault detection, and in particular to a 10,000-volt distribution network grounding fault detection system. Background Art

[0002] In the power system, the 10kV distribution network is an important link connecting the transmission system and the user terminal. Its stability and reliability are directly related to the quality and safety of power supply. In actual operation, single-phase grounding fault is one of the most common fault types in the distribution network. It has a high frequency of occurrence and a wide range of impact, because a one-way grounding fault may occur in any phase circuit and faults may occur at any position on the line.

[0003] Traditional single-phase grounding fault detection methods mainly rely on manual inspections and simple electrical tests. These methods are not only time-consuming and labor-intensive, but also easily affected by environmental, weather and other factors, resulting in low fault detection efficiency and may even miss the best time for emergency repairs.

[0004] In summary, how to improve the efficiency of troubleshooting in 10,000-volt distribution network is a technical problem that technicians in this field currently need to solve. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a 10,000-volt distribution network grounding fault detection system, which can significantly improve the efficiency of distribution network fault troubleshooting and detection. The specific scheme is as follows:

[0006] A 10,000-volt distribution network grounding fault detection system, comprising:

[0007] Single-phase circuit information collection module, used to collect current information, voltage information and impedance information of any phase circuit in the distribution network;

[0008] The single-phase circuit information calculation module is used to calculate the single-phase circuit operation information according to the judgment formula, wherein the judgment formula is:

[0009] ρ=S(αV t -V0)*S(βI t -I0)*S(γR t -R0)

[0010] Wherein, ρ is the single-phase circuit operation information, S is the operation conversion symbol, when S(αV t -V0)、S(βI t -I0) or S(γR t R0) is negative, the output result is 0, the t∈(1,2,3), the V tis the voltage information, α is the voltage correction coefficient, V0 is the preset voltage reference value, and I t is the current information, β is the current correction coefficient, I0 is the preset current reference value, R t is the impedance information, γ is the impedance correction coefficient, and R0 is the preset impedance reference value;

[0011] The fault information judgment module is used to judge the fault line according to the fault information and obtain the fault point information. If the error value between the single-phase circuit operation information of any phase circuit in the distribution network and the single-phase circuit operation information of the other two-phase circuits exceeds the judgment threshold, the fault information is output.

[0012] Preferably, the 10,000-volt distribution network grounding fault detection system also includes a circuit closing module, a circuit conversion module and a backup line pre-set in the distribution network, wherein after the circuit closing module cuts off the fault circuit according to the output fault information, the circuit conversion module connects the backup line to the fault circuit.

[0013] Preferably, the circuit closing module also includes a fault circuit closing unit and a traveling wave ranging unit, wherein, after the circuit closing module cuts off the fault circuit according to the output fault information, the fault circuit closing unit closes the fault circuit, and the traveling wave ranging unit transmits a traveling wave ranging signal from both ends of the fault circuit, and determines the fault point location according to the traveling wave return signal.

[0014] Preferably, the 10,000-volt distribution network grounding fault detection system also includes a database for recording historical fault data of the distribution network.

[0015] Preferably, the 10,000-volt distribution network grounding fault detection system also includes a distribution network management platform for displaying the fault point information to the distribution network management personnel or maintenance personnel.

[0016] Preferably, the 10,000-volt distribution network grounding fault detection system further includes a fault alarm module for sending a danger signal to the fault point location.

[0017] The present invention provides a 10,000-volt distribution network ground fault detection system, including a single-phase circuit information acquisition module, used to collect current information, voltage information and impedance information of any phase circuit in the distribution network; a single-phase circuit information calculation module, used to calculate the single-phase circuit operation information according to a judgment formula; a fault information judgment module, used to judge the fault line according to the fault information, obtain the fault point information, and output the fault information if the error value between the single-phase circuit operation information of any phase circuit in the distribution network and the single-phase circuit operation information of the other two-phase circuits exceeds the judgment threshold. It can be seen that the present invention performs a set operation on the current, voltage and impedance of any single-phase line in the distribution network, and quickly determines whether the line has a fault according to the relationship between the operation result and the judgment threshold, thereby significantly improving the efficiency of distribution network fault detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the implementation scheme of the present invention or the technical scheme in the prior art, the drawings required for use in the implementation scheme or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only the implementation scheme of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0019] Figure 1 A schematic structural diagram of a 10,000-volt distribution network grounding fault detection system provided for an implementation scheme of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The embodiment of the present invention provides a 10,000-volt distribution network ground fault detection system. Figure 1 As shown, including:

[0022] The single-phase circuit information acquisition module 1 is used to collect the current information, voltage information and impedance information of any phase circuit in the distribution network;

[0023] The single-phase circuit information acquisition module is pre-set at each node of the distribution network according to the actual needs of the distribution network, and detects faults between the nodes of the distribution network at any time. Of course, it can also be set at only one place to reduce costs.

[0024] When the power of the distribution network is transmitted normally, the voltage value tends to a stable state. It may fluctuate due to other factors, but it will not change significantly. By monitoring it, we can determine whether the distribution network circuit is normal. Similarly, when the power of the distribution network is transmitted normally, the current value tends to a stable state. It may fluctuate due to other factors, but it will not change significantly. By monitoring it, we can determine whether the distribution network circuit is normal. Impedance data, that is, insulation parameters, are important parameters for the operation of distribution network circuits. By monitoring the insulation, the safety of workers who come into contact with cables and the safety of the circuit surroundings can be guaranteed.

[0025] The single-phase circuit information calculation module 2 is used to calculate the single-phase circuit operation information according to the judgment formula, wherein the judgment formula is:

[0026] ρ=S(αV t -V0)*S(βI t -I0)*S(γR t -R0)

[0027] Wherein, ρ is the single-phase circuit operation information, S is the operation conversion symbol, when S(αV t -V0)、S(βI t -I0) or S(γR t R0) is negative, the output result is 0. The above t∈(1,2,3) respectively represent the first phase circuit, the second phase circuit and the third phase circuit. According to different values, the judgment unit collects various parameters of different circuits. The above V t is the voltage information, α is the voltage correction coefficient, and the distribution network management personnel correct the voltage value according to the actual working conditions of the distribution network. V0 is the preset voltage reference value, and I t is the above current information, β is the current correction coefficient, and the distribution network management personnel correct the current value according to the actual working conditions of the distribution network. I0 is the preset current reference value, and R t is the impedance information, the above γ is the impedance correction coefficient, the distribution network management personnel correct the impedance value according to the actual working conditions of the distribution network, and the above R0 is the preset impedance reference value;

[0028] The fault information judgment module 3 is used to judge the fault line according to the above fault information and obtain the fault point information. If the error value between the single-phase circuit operation information of any phase circuit in the above distribution network and the single-phase circuit operation information of the other two-phase circuits exceeds the judgment threshold, the fault information is output.

[0029] In the actual power transmission process of the distribution network, a fault occurs in the three-phase circuit of the distribution network. By summarizing and analyzing the single-phase circuit operation information of each phase circuit in the three-phase circuit, if there is an error value between the single-phase circuit operation information of one phase circuit and the other two phases, the error value can be an absolute value error of the value or a variance of the value. If the error value exceeds the judgment threshold, it is judged that a fault has occurred, the fault line is determined, and the power transmission of the fault line is cut off, and an alternative transmission line is provided for the fault line. The judgment threshold is set differently at different nodes or at different working times, and is specifically determined by the distribution network management personnel according to the actual working conditions of the distribution network.

[0030] In order to improve the working efficiency of the distribution network, a specific implementation scheme disclosed in the present invention also includes a circuit closing module, a circuit conversion module and a backup line pre-set in the above-mentioned distribution network, wherein after the above-mentioned circuit closing module cuts off the fault circuit according to the above-mentioned output fault information, the above-mentioned circuit conversion module connects the above-mentioned backup line to the above-mentioned fault circuit.

[0031] The circuit closing module and the circuit conversion module are set at each node of the distribution network. If the circuit between adjacent nodes is a fault circuit, that is, there is fault information, the circuit closing module set at the adjacent node cuts off the fault circuit, and the circuit conversion module at the adjacent node connects the backup line to the node and outputs the main line power through the backup line.

[0032] After determining that there is a problem with the circuit, the circuit closing module cuts off the faulty circuit to reduce the potential safety hazards around the fault point. The circuit conversion module connects the transmission nodes at both ends of the fault point line to the backup line to ensure normal power transmission of the circuit.

[0033] In order to further improve the accuracy of fault detection, so that distribution network managers and maintenance personnel can better determine the fault location, the above-mentioned circuit closing module also includes a fault circuit closing unit and a traveling wave ranging unit, wherein after the above-mentioned circuit closing module cuts off the above-mentioned fault circuit according to the above-mentioned output fault information, the above-mentioned fault circuit closing unit closes the above-mentioned fault circuit, and the above-mentioned traveling wave ranging unit transmits traveling wave ranging signals from both ends of the above-mentioned fault circuit, and determines the fault point location according to the traveling wave return signal.

[0034] The traveling wave ranging unit has a transmitting end and a receiving end. It transmits traveling wave signals from both ends of the faulty cable at the same time, waits for the traveling wave return signal, and quickly locates the fault point based on the time difference of the return, obtains the fault point location information, and thus determines the fault point location.

[0035] In order to improve the management and maintenance efficiency of distribution network management personnel and maintenance personnel, a specific implementation scheme disclosed by the present invention also includes a database for recording the historical fault data of the above distribution network.

[0036] The database storage records include data generated by the single-phase circuit information acquisition module, the single-phase circuit information calculation module and the fault information judgment module, the operating status and operation records of the circuit closing module, the circuit conversion module and the backup line, and the historical fault data of the distribution network.

[0037] In order to further improve the management and maintenance efficiency of distribution network managers and maintenance personnel, a specific implementation scheme disclosed in the present invention also includes a distribution network management platform for displaying the above-mentioned fault point information to the above-mentioned distribution network managers or maintenance personnel.

[0038] The fault point information display includes the location of the entire fault circuit, the current information, voltage information and impedance information collected by the single-phase circuit information acquisition module, the single-phase circuit operation information calculated by the single-phase circuit information calculation module, the fault information output by the fault information judgment module, the fault point location determined by the above-mentioned circuit closing module, the working status of the circuit closing module, the working status of the circuit conversion module, the working status of the backup line and the historical fault data of the fault circuit recorded in the database.

[0039] In order to further improve the operational safety of distribution network management personnel and maintenance personnel, a specific implementation scheme disclosed in the present invention also includes a fault alarm module for sending a danger signal to the above-mentioned fault point location.

[0040] The fault alarm module can send an alarm to the fault point through traditional methods such as sound and light, or it can be displayed on the distribution network management platform. Specifically, the coordinates of the fault point location can be displayed on the map of the distribution network management platform, and a danger reminder can be set near the coordinates of the fault point.

[0041] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0042] The above is a detailed introduction to a 10,000-volt distribution network grounding fault detection system provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above implementation plan is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A 10,000-volt distribution network ground fault detection system, characterized in that: include; Single-phase circuit information collection module, used to collect current information, voltage information and impedance information of any phase circuit in the distribution network; The single-phase circuit information calculation module is used to calculate the single-phase circuit operation information according to the judgment formula, wherein the judgment formula is: ρ=S(αV t -V0*S(βI t -I0)*S(γR t -R0) Wherein, ρ is the single-phase circuit operation information, S is the operation conversion symbol, when S(αV t -V0)、S(βI t -I0) or S(γR t R0) is negative, the output result is 0, the t∈(1,2,3), the V t is the voltage information, α is the voltage correction coefficient, V0 is the preset voltage reference value, and I t is the current information, β is the current correction coefficient, I0 is the preset current reference value, R t is the impedance information, γ is the impedance correction coefficient, and R0 is the preset impedance reference value; The fault information judgment module is used to judge the fault line according to the fault information and obtain the fault point information. If the error value between the single-phase circuit operation information of any phase circuit in the distribution network and the single-phase circuit operation information of the other two-phase circuits exceeds the judgment threshold, the fault information is output.

2. The 10,000-volt distribution network ground fault detection system according to claim 1, characterized in that: It also includes a circuit closing module, a circuit conversion module and a backup line pre-set in the distribution network, wherein after the circuit closing module cuts off the fault circuit according to the output fault information, the circuit conversion module connects the backup line to the fault circuit.

3. The 10,000-volt distribution network ground fault detection system according to claim 2, characterized in that: The circuit closing module also includes a fault circuit closing unit and a traveling wave ranging unit, wherein after the circuit closing module cuts off the fault circuit according to the output fault information, the fault circuit closing unit closes the fault circuit, and the traveling wave ranging unit transmits traveling wave ranging signals from both ends of the fault circuit, and determines the fault point location according to the traveling wave return signal.

4. The 10,000-volt distribution network ground fault detection system according to claim 3, characterized in that: Also included is a database for recording historical fault data of the power distribution network.

5. The 10,000-volt distribution network ground fault detection system according to claim 4, characterized in that: It also includes a distribution network management platform, which is used to display the fault point information to the distribution network management personnel or maintenance personnel.

6. The 10,000-volt distribution network ground fault detection system according to claim 5, characterized in that: It also includes a fault alarm module, which is used to send a danger signal to the fault point.

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