CN105891679A - Fault detection system and method for electric power grid - Google Patents

Abstract

The invention discloses a power grid fault detection system and a fault detection method. The power grid is connected with a detection circuit, and the branch lines are respectively provided with a plurality of current transformers, and the current transformers are used to collect current signals on the power grid. The detection circuit is connected to a fault judgment circuit, the fault judgment circuit is provided with a photoelectric conversion unit, a fault level judgment unit and a signal generator, the fault judgment circuit is connected with an alarm processing circuit, and the alarm processing circuit is also connected with a monitoring center. The advantage of the present invention is that: a current transformer is installed on the detection circuit, the current information on the power grid is obtained through the current transformer, and the information of the fault signal is determined through a plurality of judging units, and the fault signal is determined through the alarm device and the monitoring center. The information is released, so that faults can be eliminated at the fastest speed. The invention has simple structure, convenient operation and low cost.

Description

A power grid fault detection system and fault detection method

technical field

The invention belongs to the technical field of power grids, and in particular relates to a power grid fault detection system and a fault detection method.

Background technique

my country's distribution network has the characteristics of complex line structure, diverse environment, frequent and complex faults, and heavy maintenance workload. If a fault occurs in a certain section of the distribution line, it is necessary to check the location of the fault one by one. Not only is the work intensity high, but it will also delay the repair time and affect the reliability of power supply. The normal use and service life of power grid terminal equipment such as meters have a great impact. At present, the grid voltage fluctuates greatly, especially in rural areas, the grid voltage fluctuates even more; too high grid voltage often shortens the service life of grid terminal equipment, and sometimes even burns grid terminal equipment; while too low The grid voltage may cause the grid terminal equipment to fail to work normally. Therefore, the industry needs a detection device that can monitor the grid in real time to solve the problems faced by the industry.

The traditional fault location is to use the data collected by the feeder terminal unit to analyze the fault location. The method is to establish the grid model in the main power distribution station in advance to form the topology of the grid. When a fault occurs, the distribution master station combines the data uploaded by the feeder terminal unit with the topological structure of the power grid, and uses the fault location algorithm to calculate the location of the fault.

Traditional fault location methods have the following problems:

1. Due to the huge power grid and complex conditions, it is difficult and time-consuming to create a suitable power grid model.

2. There is no uniform fault location algorithm. Different power grid models need to adopt appropriate fault location algorithms, which cannot be used universally. And usually the amount of calculation is very large and takes a long time.

However, most faults occur in a single location and do not require very precise positioning. At this time, the feeder terminal unit is used to collect a lot of power grid information, and then the complex fault location algorithm is used for calculation, and the hardware cost and time cost are very large.

Contents of the invention

Purpose of the invention: The purpose of the invention is to solve the deficiencies in the prior art and provide a low-cost power grid fault detection system and fault detection method that can quickly and simply locate a single fault.

Technical solution: A power grid fault detection system according to the present invention includes a power grid, the grid is connected to a detection circuit, and the detection circuit is provided with a plurality of branch lines, and the branch lines are respectively provided with multiple A current transformer, the current transformer is used to collect the current signal on the power grid, the detection line is connected to the fault judgment circuit, the fault judgment circuit is provided with a photoelectric conversion unit, a fault level judgment unit and a signal generator, so that The fault judging circuit is connected with an alarm processing circuit, and an alarm device is arranged on the alarm processing circuit.

Further, the alarm processing circuit is also connected to a monitoring center, and the monitoring center is provided with a wireless signal generator.

Further, the failure level judging unit is provided with a failure comparison unit, and a plurality of failure level standards are set in the failure comparison unit.

A power grid fault detection method includes the steps of:

(1) Install fault indicators in the power grid, the fault indicators are distributed on the lines of the power grid, the lines include the main line and at least one branch line, and each line is equipped with at least one fault indicator;

(2) Establish a tree model with fault indicators as nodes; in the tree model: the fault indicators on the same line are connected sequentially, and the latter fault indicator is used as a child node of the previous fault indicator; on the branch line The first fault indicator on the main line is the child node of the last fault indicator on the main line, and the first fault indicator on the secondary branch line is the child node of the last fault indicator on the upper branch line ;

(3) Mark and number the fault indicators; the fault indicators on the same line are numbered sequentially, and the first fault indicator on the branch line is increased by 1 on the basis of the number of the last fault indicator on the main line; The first fault indicator on the secondary branch line is increased by 1 on the basis of the number of the last fault indicator on the upper branch line;

(4) Traversing all paths of the tree model with fault indicators as nodes, judging whether the number of fault indicators indicating faults on each path is consistent with the number of the fault indicator with the largest number, and if so, put the number The identification and number of the largest fault indicator as the fault coordinates of the path;

(5) Obtain the fault indicator with the largest number component of the fault coordinates, and locate the circuit fault behind it;

(6) When a fault occurs in the distribution network is detected, display the faulty line in the distribution network on the display screen, and obtain the terminal corresponding to the faulty line; and send a fault prompt message to the the terminal;

(7) Acquiring fault information of the faulty line from a preset associated system, and displaying the fault information on the display screen, wherein the fault information at least includes: a fault interval, and the fault interval is all The line section where the fault occurred in the faulty line is located.

Further, if the number of fault indicators indicating a fault on a path is inconsistent with the number of the fault indicator with the largest number, it is judged whether the ratio of the number of fault indicators indicating a fault to the number of the fault indicator with the largest number is greater than the set value Determine the threshold, if so, use the number of the fault indicator with the largest number as the fault coordinates of the path, and use the fault coordinates for fault location; otherwise, consider that there is no fault in this path.

Further, the set threshold is 60%.

Further, after displaying the faulty line in the distribution network, the method further includes: modifying the operation status of the faulty line to be abnormal; and sending a work order to the handheld terminal corresponding to the faulty line, wherein, The work order includes at least a rush repair task.

Further, after sending the work order to the hand-held terminal corresponding to the faulty line, the method further includes: establishing a communication connection between the hand-held terminal and the command center; The video information of the commander in the center is sent to the handheld terminal through the communication connection.

Further, after sending the work order to the handheld terminal corresponding to the faulty line, the method further includes: after receiving the completion instruction sent by the handheld terminal, restoring the operation status of the faulty line to normal, wherein , the completion instruction is used to indicate that the fault occurred in the distribution network has been eliminated.

Further, based on the received operating parameters of the distribution network, detecting whether a fault occurs in the distribution network includes: detecting whether a foreign object appears on a line that is distributing power in the distribution network, wherein, after detecting that the In the case of a foreign object appearing on the power distribution line, it is determined that the distribution network has a fault; or detecting whether the current on the power distribution line in the distribution network has a sudden change, wherein, after detecting that the current has a sudden change In the case of , it is determined that the distribution network fails.

Beneficial effects: Compared with the prior art, the present invention has the advantages that: a detection circuit, a fault judgment circuit, an alarm processing circuit and a monitoring center are provided, a current transformer is provided on the detection circuit, and the current transformer is used to obtain The current information on the power grid, and determine the information of the fault signal through multiple judgment units, so as to determine whether there is a fault in the power grid, and release the information through the alarm device and the monitoring center, so that the fault can be eliminated at the fastest speed. The invention has simple structure, convenient operation and low cost.

The fault detection method of the present invention detects whether a fault occurs in the distribution network based on the received operating parameters of the distribution network; The faulty line in the network; obtain the terminal corresponding to the faulty line; send a fault prompt message to the terminal, and display the faulty faulty line on the display screen when a fault occurs in the distribution network is detected , and send a fault prompt message to the terminal corresponding to the faulty line, so that the holders of the terminal, such as emergency repair personnel, can quickly know that there is a fault in the distribution network, and achieve the purpose of quickly repairing the faulty line, thereby realizing the improvement of the distribution network. The technical effect of fault maintenance efficiency further solves the technical problem of low fault maintenance efficiency of distribution network in the prior art.

Description of drawings

Fig. 1 is the fault detection system structural representation of the present invention;

Fig. 2 is a flowchart of a fault detection method according to an embodiment of the present invention;

Fig. 3 is a schematic diagram of the installation position and the structure of the fault indicator of the present invention.

detailed description

The present invention is described in detail below in conjunction with accompanying drawing and specific embodiment:

According to a power grid fault detection system shown in FIG. 1 , a power grid 1 is provided, the power grid 1 is connected to a detection circuit 2 , and a plurality of branch lines 201 are arranged on the detection circuit 2 .

Further, a plurality of current transformers 202 are respectively arranged on the branch lines 201, and the current transformers 202 are used to collect current signals on the grid 1.

Still further, the detection line 2 is connected to the fault judgment circuit 3, and the fault judgment circuit 3 is provided with a photoelectric conversion unit 301, a fault level judgment unit 302 and a signal generator 303.

Still further, the fault judgment circuit 3 is connected with an alarm processing circuit 4, and the alarm processing circuit 4 is provided with an alarm device 401.

Furthermore, the alarm processing circuit 4 is also connected with a monitoring center 5, and the monitoring center 5 is provided with a wireless signal generator.

Still further, the failure level judging unit 302 is provided with a failure comparison unit 304, and a plurality of failure level standards are set in the failure comparison unit 304.

When in use, a power grid 1 is provided, and a detection circuit 2 is arranged on the power grid 1. Since the detection circuit 2 is provided with a plurality of current transformers 202, the information of the current is obtained from the power grid 1 through the current transformers 202, and the obtained current signal Pass to the fault judgment circuit 3, the current signal is first transmitted to the photoelectric conversion unit 301, the photoelectric conversion unit 301 converts the current signal into an optical signal, and then transmits the optical signal to the fault level judgment unit 302, because the fault level judgment unit 302 is set There is a fault comparison unit 304, so the fault level judging unit 302 will compare the received optical signal with the fault comparison unit 304, and find a value that matches or is close to it, so as to obtain the fault level corresponding to the optical signal, and The fault level is transmitted to the signal generator 303, and the signal generator 303 judges whether to trigger the alarm device 401 according to the fault level, and the fault level is transmitted to the monitoring center 5 by the alarm device 401, and the personnel on duty in the monitoring center 5 do a fault check. Further analysis to determine whether to further deal with this fault.

A kind of fault detection method as shown in Figure 2, comprises the following steps:

(1) Install fault indicators in the power grid, the fault indicators are distributed on the lines of the power grid, the lines include the main line and at least one branch line, and each line is equipped with at least one fault indicator;

(2) Establish a tree model with fault indicators as nodes; in the tree model: the fault indicators on the same line are connected sequentially, and the latter fault indicator is used as a child node of the previous fault indicator; on the branch line The first fault indicator on the main line is the child node of the last fault indicator on the main line, and the first fault indicator on the secondary branch line is the child node of the last fault indicator on the upper branch line ;

(3) Mark and number the fault indicators; the fault indicators on the same line are numbered sequentially, and the first fault indicator on the branch line is increased by 1 on the basis of the number of the last fault indicator on the main line; The first fault indicator on the secondary branch line is increased by 1 on the basis of the number of the last fault indicator on the upper branch line;

(4) Traversing all paths of the tree model with fault indicators as nodes, judging whether the number of fault indicators indicating faults on each path is consistent with the number of the fault indicator with the largest number, and if so, put the number The identification and number of the largest fault indicator as the fault coordinates of the path;

(5) Obtain the fault indicator with the largest number component of the fault coordinates, and locate the circuit fault behind it;

(6) When a fault occurs in the distribution network is detected, display the faulty line in the distribution network on the display screen, and obtain the terminal corresponding to the faulty line; and send a fault prompt message to the the terminal;

(7) Acquiring fault information of the faulty line from a preset associated system, and displaying the fault information on the display screen, wherein the fault information at least includes: a fault interval, and the fault interval is all The line section where the fault occurred in the faulty line is located.

Further, if the number of fault indicators indicating a fault on a path is inconsistent with the number of the fault indicator with the largest number, it is judged whether the ratio of the number of fault indicators indicating a fault to the number of the fault indicator with the largest number is greater than the set value Determine the threshold, if so, use the number of the fault indicator with the largest number as the fault coordinates of the path, and use the fault coordinates for fault location; otherwise, consider that there is no fault in this path.

Further, the set threshold is 60%.

Further, after displaying the faulty line in the distribution network, the method further includes: modifying the operation status of the faulty line to be abnormal; and sending a work order to the handheld terminal corresponding to the faulty line, wherein, The work order includes at least a rush repair task.

Further, after sending the work order to the hand-held terminal corresponding to the faulty line, the method further includes: establishing a communication connection between the hand-held terminal and the command center; The video information of the commander in the center is sent to the handheld terminal through the communication connection.

Further, after sending the work order to the handheld terminal corresponding to the faulty line, the method further includes: after receiving the completion instruction sent by the handheld terminal, restoring the operation status of the faulty line to normal, wherein , the completion instruction is used to indicate that the fault occurred in the distribution network has been eliminated.

Further, based on the received operating parameters of the distribution network, detecting whether a fault occurs in the distribution network includes: detecting whether a foreign object appears on a line that is distributing power in the distribution network, wherein, after detecting that the In the case of a foreign object appearing on the power distribution line, it is determined that the distribution network has a fault; or detecting whether the current on the power distribution line in the distribution network has a sudden change, wherein, after detecting that the current has a sudden change In the case of , it is determined that the distribution network fails.

Referring to Figure 3, fault indicators can be installed on overhead lines, power cables, cabinets, ring network cabinets, and cable branch boxes to indicate faults such as grid short circuit or single-phase grounding. The fault indicator mainly includes two parts: the sensing part, including the ground fault sensor and the short circuit fault sensor; The communication module sends relevant alarm information to the monitoring center. When a short circuit or ground fault occurs in the line, all fault indicators from the substation outlet to the fault point will flip or flash.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, can use the technical content disclosed above to make some changes or modify equivalent embodiments with equivalent changes, but all the content that does not depart from the technical solution of the present invention, according to the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments by the technical essence still belong to the scope of the technical solution of the present invention.

Claims (10)

1. A power grid fault detection system, characterized in that: comprising a grid (1), the grid (1) is connected to a detection circuit (2), and the detection circuit (2) is provided with a plurality of branch lines (201), the branch lines (201) are respectively provided with a plurality of current transformers (202), the current transformers (202) are used to collect current signals on the power grid (1), and the detection line (2 ) is connected to the fault judgment circuit (3), and the fault judgment circuit (3) is provided with a photoelectric conversion unit (301) and a fault level judgment unit (302) and a signal generator (303), and the fault judgment circuit (3) ) is connected with an alarm processing circuit (4), and the alarm processing circuit (4) is provided with an alarm device (401). 2. A kind of power grid fault detection system according to claim 1, characterized in that: the alarm processing circuit (4) is also connected to a monitoring center (5), and the monitoring center (5) is provided with a wireless signal generator. 3. A power grid fault detection system according to claim 1, characterized in that: said fault level judging unit (302) is provided with a failure comparison unit (304), and a plurality of failure level standards are set in the failure comparison unit (304). 4. A power grid fault detection method, characterized in that: comprising the steps of: (1) Install fault indicators in the power grid, the fault indicators are distributed on the lines of the power grid, the lines include the main line and at least one branch line, and each line is equipped with at least one fault indicator; (2) Establish a tree model with fault indicators as nodes; in the tree model : The fault indicators on the same line are connected sequentially, and the latter fault indicator is the child node of the previous fault indicator ;First FI on a branch line As a child of the last FI on the main line, the first FI on a secondary branch line As a child node of the last fault indicator on the branch line of the upper level; (3) Identify and number the fault indicators; the fault indicators on the same line are numbered sequentially, and the fault indicators on the branch line A fault indicator is increased by 1 based on the number of the last fault indicator on the trunk line; the first fault indicator on the secondary branch line is the number of the last fault indicator on the upper branch line on the basis of increase by 1; (4) Traversing all paths of the tree model with fault indicators as nodes, judging whether the number of fault indicators indicating faults on each path is consistent with the number of the fault indicator with the largest number, and if so, put the number The identification and number of the largest fault indicator as the fault coordinates of the path; (5) Obtain the fault indicator with the largest number component of the fault coordinates, and locate the circuit fault behind it; (6) When a fault occurs in the distribution network, display the faulty line in the distribution network on the display screen, and obtain the terminal corresponding to the faulty line ; and sending a fault prompt message to the terminal; (7) Acquiring fault information of the faulty line from a preset associated system, and displaying the fault information on the display screen, wherein the fault information at least includes: a fault interval, and the fault interval is all A fault occurred in the faulty line The line interval where the position is located. 5. A kind of electric power grid fault detection method according to claim 4, is characterized in that: if the quantity of the fault indicator indicating fault on a path is inconsistent with the serial number of the fault indicator with the largest number, then judge the fault indicating fault Whether the ratio of the number of indicators to the number of the fault indicator with the largest number is greater than the set threshold, if so, the number of the fault indicator with the largest number is used as the fault coordinates of the path, and the fault coordinates are used for fault location ; Otherwise, it is considered that there is no fault in this path. 6. A kind of power grid fault detection method according to claim 5, is characterized in that: described setting threshold is 60%. 7. A kind of power grid fault detection method according to claim 4, is characterized in that: after displaying the fault line in the distribution network, the method further comprises: modifying the operating state of the fault line to Abnormal; and sending a work order to the hand-held terminal corresponding to the faulty line, wherein the work order at least includes a repair task. 8. A power grid fault detection method according to claim 7, characterized in that: after sending the work order to the hand-held terminal corresponding to the faulty line, the method further comprises: establishing the hand-held terminal with the command center The communication connection between; Obtain the video information of the commander in the command center through the camera equipment of the command center, and send the video Information is sent to the handheld terminal through the communication connection. 9. A power grid fault detection method according to claim 7, characterized in that: after sending the work order to the hand-held terminal corresponding to the faulty line, the method further comprises: after receiving the hand-held terminal sending After completing the instruction, restore the operation state of the faulty line to normal, wherein the completion instruction is used to indicate that the fault occurred in the distribution network has been eliminated. 10. A power grid fault detection method according to claim 4, characterized in that: based on the received operating parameters of the distribution network, detecting whether a fault occurs in the distribution network comprises; Whether there is a foreign object on the line that is distributing power, wherein, in the case that a foreign object is detected on the line that is distributing power, it is determined that a fault occurs in the distribution network; Whether there is a sudden change in the current on the line, wherein, when the current is detected In the case of a sudden change, it is determined that the distribution network is faulty.