Method and system for detecting electric leakage of low-voltage transformer area

Abstract

The invention provides a low-voltage transformer area electric leakage detection method and system, and the method comprises the steps: transmitting a first feature signal to a first position of a to-be-detected line according to a received electric leakage detection instruction; wherein the first characteristic signal is transmitted through a preset signal transmitting device, and is used for positioning a fault position; receiving a second characteristic signal corresponding to the first characteristic signal at a second position of the to-be-detected line; wherein the second characteristic signal is received through a preset signal receiving device and is used for determining an electric leakage fault of the to-be-detected line; and determining whether the to-be-detected line has an electric leakage fault or not according to the receiving condition of the second characteristic signal. According to the invention, through signal emission and signal reception, the technical problem of low detection efficiency of an existing low-voltage transformer area electric leakage detection method is solved, and the electric leakage detection efficiency of the low-voltage transformer area is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of low-voltage station leakage detection, and in particular to a method and system for low-voltage station leakage detection. Background Art

[0002] With the deepening of power grid transformation, the vast majority of urban residents have convenient electricity use, and various household appliances have entered the homes of urban residents in large numbers, improving people's quality of life. However, with the construction of cities and new rural areas, the demand for electricity is growing, causing some of the already built low-voltage lines to increase in load disorderly, resulting in unbalanced load development; or because the zero line diameter is too small in the design; or because of inadequate operation and maintenance, the low-voltage line has fallen into disrepair, etc., which eventually leads to the zero line being overloaded and burned out or the load imbalance causing the zero line to be energized. After the zero line is energized due to various reasons, it is difficult for the power supply department to find defects and faults during normal operation and maintenance. Usually, residents report to the power department for warranty after their household appliances cannot be used normally or the appliances are burned out, phase-missing, or electric shock occurs when the zero line is energized, and then the power repair department will investigate the fault.

[0003] Due to the different personal experience and professional skills of on-site staff, the methods of finding faults and the time of troubleshooting are also different. Experienced staff can find and eliminate faults in a shorter time, while inexperienced staff often take a longer time to find the cause of the fault. It may even require additional staff. Summary of the invention

[0004] The purpose of the present invention is to provide a method and system for detecting leakage in low-voltage areas, so as to solve the technical problem of how to improve the efficiency of leakage detection in low-voltage areas.

[0005] On the one hand, a method for detecting leakage in a low-voltage area is provided, comprising:

[0006] According to the received leakage detection instruction, a first characteristic signal is sent to a first position of the line to be tested; wherein the first characteristic signal is sent through a preset signal transmitting device and is used to locate the fault position;

[0007] Receiving a second characteristic signal corresponding to the first characteristic signal at a second position of the circuit to be tested; wherein the second characteristic signal is received by a preset signal receiving device and is used to determine a leakage fault of the circuit to be tested;

[0008] Determine whether the circuit to be tested has a leakage fault according to the reception status of the second characteristic signal.

[0009] Preferably, the preset signal transmitting equipment is connected to the line to be tested through a test line, forming a loop between the signal transmitting equipment, the leakage fault location in the line to be tested and the earth, and sends a first characteristic signal to the line to be tested when working in a power grid outage state.

[0010] Preferably, the preset signal receiving device is preset in the circuit to be tested, and is used to determine the leakage fault position according to the reception status of the second characteristic signal.

[0011] Preferably, the method further comprises disconnecting the path between the line to be tested and the power grid when receiving the leakage detection instruction and before sending the first characteristic signal to the line to be tested.

[0012] Preferably, the determining whether there is a leakage fault in the circuit to be tested specifically includes: if the signal receiving device detects a second characteristic signal, it is determined that there is a leakage fault in the circuit to be tested, and the leakage fault position is between the signal transmitting equipment and a preset position.

[0013] Preferably, it also includes, if the signal receiving device cannot detect the second characteristic signal, detecting the current vector of the circuit to be tested by means of a differential current sensor in the signal transmitting equipment; if the detected current vector meets a preset fault range, determining that a leakage fault exists in the circuit to be tested.

[0014] Preferably, the differential current sensor detects the four-phase current vector of the circuit to be tested, and measures the online leakage current and the daily average leakage current value in real time.

[0015] Preferably, it also includes, when there is a leakage fault in the circuit to be tested, adjusting the second position close to the first position until the difference between the first characteristic signal and the second characteristic signal meets the preset fault signal characteristic, determining the location of the leakage fault, and outputting an alarm signal.

[0016] On the other hand, a detection system for low-voltage area leakage is also provided to implement the detection method for low-voltage area leakage, including:

[0017] A detection start module, used to send a first characteristic signal to a first position of the line to be tested according to the received leakage detection instruction; wherein the first characteristic signal is sent through a preset signal transmitting device and is used to locate the fault position;

[0018] A signal sending module, used for receiving a second characteristic signal corresponding to the first characteristic signal at a second position of the circuit to be tested; wherein the second characteristic signal is received by a preset signal receiving device and is used for determining a leakage fault of the circuit to be tested;

[0019] A fault detection module is used to determine whether there is a leakage fault in the circuit to be tested according to the reception status of the second characteristic signal.

[0020] In summary, the implementation of the embodiments of the present invention has the following beneficial effects:

[0021] The present invention provides a method and system for detecting leakage in a low-voltage power distribution area. A second characteristic signal corresponding to a first characteristic signal is received at a second position of the circuit to be tested by a signal receiving device. Based on the second characteristic signal, it is determined whether there is a leakage fault in the circuit to be tested. By means of signal transmission and signal reception, the technical problem of low detection efficiency of the existing method for detecting leakage in a low-voltage power distribution area is alleviated, thereby improving the detection efficiency of leakage in a low-voltage power distribution area. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0023] Figure 1 The main flow diagram of a method for detecting leakage in a low-voltage area according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 FIG. 1 is a schematic diagram of an embodiment of a method for detecting leakage in a low-voltage area provided by the present invention. In this embodiment, the method comprises the following steps:

[0026] Step S1, according to the received leakage detection instruction, send a first characteristic signal to the first position of the line to be tested; wherein, the first characteristic signal is sent through a preset signal transmitting equipment for locating the fault position; the preset signal transmitting equipment is connected to the line to be tested through a test line, forming a loop between the signal transmitting equipment, the leakage fault position in the line to be tested and the earth, and when working in a power grid outage state, sends the first characteristic signal to the line to be tested. It can be understood that the above-mentioned signal transmitting equipment is the host of the low-voltage leakage locator, and the low-voltage leakage locator needs to work in a power grid outage state. The host of the low-voltage leakage locator is connected to the line to be tested through a test line, so that a loop is formed from the host of the low-voltage leakage locator to the leakage fault position in the line to be tested to the earth to the host of the low-voltage leakage locator, and the host of the low-voltage leakage locator sends the first characteristic signal to the fault line.

[0027] One embodiment further includes disconnecting the path between the line to be tested and the power grid when receiving the leakage detection instruction and before sending the first characteristic signal to the line to be tested.

[0028] Step S2, receiving a second characteristic signal corresponding to the first characteristic signal at a second position of the line to be tested; wherein the second characteristic signal is received by a preset signal receiving device, and is used to determine the leakage fault of the line to be tested; the preset signal receiving device is preset in the line to be tested, and is used to determine the leakage fault position according to the reception of the second characteristic signal. It can be understood that the signal receiving device is a slave of the low-voltage leakage locator, and the slave detects the characteristic signal. The slave can detect the second characteristic signal before the preset position of the leakage fault position, and the receiving slave cannot detect the second characteristic signal after the leakage fault point, thereby locating the leakage fault position of the faulty line.

[0029] Step S3, determining whether there is a leakage fault in the circuit to be tested according to the reception status of the second characteristic signal.

[0030] In one embodiment, the determining whether there is a leakage fault in the circuit to be tested specifically includes: if the signal receiving device detects a second characteristic signal, it is determined that there is a leakage fault in the circuit to be tested, and the leakage fault position is between the signal transmitting equipment and a preset position.

[0031] One embodiment further includes, if the signal receiving device cannot detect the second characteristic signal, the current vector of the circuit to be tested is detected by the differential current sensor in the signal transmitting equipment; if the detected current vector meets the preset fault range, it is determined that the circuit to be tested has a leakage fault. Wherein, the differential current sensor detects the four-phase current vector of the circuit to be tested, and measures the online leakage current and the daily average leakage value in real time. It is understandable that if the above leakage fault is not detected, the current vector of the circuit to be tested is detected by the differential current sensor in the signal transmitting equipment; according to the current vector, it is determined whether the circuit to be tested has a leakage fault. The differential current sensor is a Rogowski coil. Before the step of detecting the current vector of the circuit to be tested by the differential current sensor in the signal transmitting equipment, the method includes: connecting the Rogowski coil to the A phase, B phase, C phase and N phase of the circuit to be tested. The Rogowski coil is put on the A phase, B phase, C phase and N phase of the circuit to be tested, and the blue-black banana plug of the Rogowski coil is inserted into the corresponding color jack of the host. Select the leakage assessment function, the host detects the four-phase current vector and situation, and measures the online leakage current and daily average leakage value in real time.

[0032] In an embodiment, when there is a leakage fault in the circuit to be tested, the second position is adjusted to be close to the first position until the difference between the first characteristic signal and the second characteristic signal meets the preset fault signal characteristics, the location of the leakage fault is determined, and an alarm signal is output. It is understandable that if there is a leakage fault in the circuit to be tested, the second position is adjusted to bring the second position close to the first position until the location of the leakage fault is determined based on the first characteristic signal and the second characteristic signal. The types of the first characteristic signal and the second characteristic signal are both voltage signals; the location of the leakage fault is determined based on the difference between the first characteristic signal and the second characteristic signal. When the location of the leakage fault is determined, a preset alarm signal is sent out by the alarm device of the signal transmitting equipment. The alarm device includes: a buzzer and an LED light, and the location of the leakage fault is displayed on a display.

[0033] The embodiment of the present invention further provides a system for detecting leakage in a low-voltage area, which is used to implement the method for detecting leakage in a low-voltage area, comprising:

[0034] A detection start module, used to send a first characteristic signal to a first position of the line to be tested according to the received leakage detection instruction; wherein the first characteristic signal is sent through a preset signal transmitting device and is used to locate the fault position;

[0035] A signal sending module, used for receiving a second characteristic signal corresponding to the first characteristic signal at a second position of the circuit to be tested; wherein the second characteristic signal is received by a preset signal receiving device and is used for determining a leakage fault of the circuit to be tested;

[0036] A fault detection module is used to determine whether there is a leakage fault in the circuit to be tested according to the reception status of the second characteristic signal.

[0037] It should be noted that the system described in the above embodiment corresponds to the method described in the above embodiment. Therefore, the undetailed parts of the system described in the above embodiment can be obtained by referring to the contents of the method described in the above embodiment, and will not be repeated here.

[0038] In summary, the implementation of the embodiments of the present invention has the following beneficial effects:

[0039] The present invention provides a method and system for detecting leakage in a low-voltage power distribution area. A second characteristic signal corresponding to a first characteristic signal is received at a second position of the circuit to be tested by a signal receiving device. Based on the second characteristic signal, it is determined whether there is a leakage fault in the circuit to be tested. By means of signal transmission and signal reception, the technical problem of low detection efficiency of the existing method for detecting leakage in a low-voltage power distribution area is alleviated, thereby improving the detection efficiency of leakage in a low-voltage power distribution area.

[0040] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for detecting leakage in a low voltage area, characterized in that: include: According to the received leakage detection instruction, a first characteristic signal is sent to a first position of the line to be tested; wherein the first characteristic signal is sent through a preset signal transmitting device and is used to locate the fault position; Receiving a second characteristic signal corresponding to the first characteristic signal at a second position of the circuit to be tested; wherein the second characteristic signal is received by a preset signal receiving device and is used to determine a leakage fault of the circuit to be tested; Determine whether the circuit to be tested has a leakage fault according to the reception status of the second characteristic signal.

2. The method according to claim 1, characterized in that The preset signal transmitting equipment is connected to the line to be tested through a test line, forming a loop between the signal transmitting equipment, the leakage fault position in the line to be tested and the earth, and sends a first characteristic signal to the line to be tested when working in a power grid outage state.

3. The method according to claim 2, characterized in that The preset signal receiving device is preset in the circuit to be tested, and is used to determine the leakage fault position according to the reception condition of the second characteristic signal.

4. The method according to claim 1, characterized in that The method further includes disconnecting the path between the line to be tested and the power grid when a leakage detection instruction is received and before sending a first characteristic signal to the line to be tested.

5. The method according to claim 4, characterized in that The determining whether there is a leakage fault in the circuit to be tested specifically includes: if the signal receiving device detects a second characteristic signal, it is determined that there is a leakage fault in the circuit to be tested, and the leakage fault position is between the signal transmitting equipment and the preset position.

6. The method according to claim 5, characterized in that The method further includes detecting the current vector of the circuit to be tested by a differential current sensor in the signal transmitting equipment if the signal receiving device cannot detect the second characteristic signal; If the detected current vector meets the preset fault range, it is determined that the circuit to be tested has a leakage fault.

7. The method according to claim 6, characterized in that The differential current sensor detects the four-phase current vector of the circuit to be tested, and measures the online leakage current and the daily average leakage current value in real time.

8. The method according to claim 5 or 6, characterized in that It also includes, when there is a leakage fault in the circuit to be tested, adjusting the second position close to the first position until the difference between the first characteristic signal and the second characteristic signal meets the preset fault signal characteristic, determining the location of the leakage fault, and outputting an alarm signal.

9. A system for detecting leakage in low voltage areas, used to implement the method according to any one of claims 1 to 8, characterized in that: include, A detection start module, used to send a first characteristic signal to a first position of the line to be tested according to the received leakage detection instruction; wherein the first characteristic signal is sent through a preset signal transmitting device and is used to locate the fault position; A signal sending module, used for receiving a second characteristic signal corresponding to the first characteristic signal at a second position of the circuit to be tested; wherein the second characteristic signal is received by a preset signal receiving device and is used for determining a leakage fault of the circuit to be tested; A fault detection module is used to determine whether there is a leakage fault in the circuit to be tested according to the reception status of the second characteristic signal.

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