Apparatus and method for locating electric leakage of lines in low-voltage transformer area in power grid

Abstract

Disclosed are an apparatus and method for locating electric leakage of lines in a low-voltage transformer area in a power grid. The apparatus for locating electric leakage of lines in a low-voltage transformer area in a power grid comprises: a control module, a transformer detection module and a line detection module, wherein the transformer detection module is electrically connected to the control module, and is configured to detect whether there is a current signal in each transformer and input the current signal into the control module; and the control module is in communication connection with the line detection module, and is configured to determine, on the basis of the current signal, whether electric leakage occurs in the transformer, and output, when electric leakage occurs in the transformer, a line detection signal to the line detection module, so as to control the line detection module to detect electric energy parameters of a line corresponding to the transformer, and determine, on the basis of the electric energy parameters, a line section in which the electric leakage occurs.

Description

Power grid low-voltage substation line leakage positioning device and method

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 14, 2023, with application number 202311514570.8, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power system detection, for example, to a device and method for locating leakage in low-voltage substation lines in a power grid. Background Art

[0003] The distance of the external lines in the transformer area is long and the environment is complex. The lines often pass through various tree branches to connect with each other. However, in such an environment, the transformer and the transformer lines are easily punctured by metal, causing the insulation to be damaged, which will cause leakage of the external lines and affect the normal power supply of the lines.

[0004] In the prior art, leakage monitoring for transformer substations only focuses on the transformer itself. This means that only the leaking transformer can be located and identified, and then maintenance personnel inspect and repair all lines in the substation. This method is time-consuming, not only increasing the difficulty of maintenance personnel but also affecting the timeliness of maintenance.

[0005] Summary of the Invention

[0006] The present application provides a device and method for locating leakage current in low-voltage substation lines in a power grid, so as to solve the problem in the related art of inaccurate positioning of leakage current lines and untimely maintenance by personnel.

[0007] According to one aspect of the present application, a device for locating leakage current in a low-voltage power grid area line is provided, comprising:

[0008] Control module, transformer detection module and line detection module;

[0009] The transformer detection module is electrically connected to the control module and is configured to detect whether there is a current signal in the transformer and input the current signal to the control module;

[0010] The control module is communicatively connected to the line detection module and is configured to determine whether the transformer is leaking electricity based on the current signal and output a line detection signal to the line detection module when the transformer is leaking electricity, so as to control the line detection module to detect the electrical energy parameters of the line corresponding to the transformer; and determine the line section with leakage based on the electrical energy parameters.

[0011] Optionally, the transformer detection module includes: a current mutual induction unit and a signal transmission circuit;

[0012] The current mutual inductance unit is arranged on the neutral line of the transformer and is electrically connected to the signal transmission circuit, and is arranged to generate a current signal in the event of a transformer leakage;

[0013] The signal transmission circuit is electrically connected to the control module and is configured to input the current signal into the control module.

[0014] Optionally, the current mutual inductance unit includes: a magnet and an induction coil;

[0015] The magnet is arranged around the neutral line, and the induction coil is arranged around the magnet and is electrically connected to the signal transmission circuit.

[0016] Optionally, the signal transmission circuit includes: a rectifier bridge, a unidirectional thyristor, a trip coil and a trip switch;

[0017] The input end of the rectifier bridge is connected to the output end of the current mutual inductance unit, and the first output end of the rectifier bridge is connected to the gate of the unidirectional thyristor;

[0018] The anode of the unidirectional thyristor is connected to the first input end of the tripping coil, and the cathode of the unidirectional thyristor is connected to the second input end of the tripping coil; the second input end of the tripping coil is also connected to the control module through the tripping switch.

[0019] Optionally, the line detection module includes: at least two electric energy detection meters;

[0020] The electric energy detection meters are respectively arranged at different positions on the line and are configured to measure the electric energy parameters of different line sections.

[0021] According to another aspect of the present application, a method for locating leakage current in a low-voltage power grid line is provided. The method is applied to a leakage current locating device, comprising:

[0022] Acquire current signal;

[0023] Determine whether the transformer is leaking according to the current signal;

[0024] When it is determined that the transformer is leaking according to the current signal, a line detection signal is output to the line detection module to control the line detection module to detect the power parameters of the line corresponding to the transformer;

[0025] Determine the leakage line section based on the electrical energy parameters.

[0026] Optionally, judging whether the transformer is leaking electricity based on the current signal includes:

[0027] Determine whether the current value in the current signal is 0.

[0028] Optionally, outputting a line detection signal to a line detection module includes:

[0029] Obtain the power supply parameters of the A-phase line, the B-phase line, and the C-phase line of the corresponding transformer;

[0030] Determine whether the phase A line has leakage according to the power supply parameters of the phase A line, determine whether the phase B line has leakage according to the power supply parameters of the phase B line, and determine whether the phase C line has leakage according to the power supply parameters of the phase C line;

[0031] In the event of leakage in any of the A-phase line, the B-phase line, and the C-phase line, a line detection signal of the corresponding line is output to the line detection module.

[0032] Optionally, determining whether the phase A line has leakage according to the power supply parameters of the phase A line, determining whether the phase B line has leakage according to the power supply parameters of the phase B line, and determining whether the phase C line has leakage according to the power supply parameters of the phase C line include:

[0033] Determine whether the power supply parameters of phase A are within the standard power supply parameter range;

[0034] When the power supply parameters of the phase A line are within the standard power supply parameter range, the phase A line does not leak electricity; when the power supply parameters of the phase A line are not within the standard power supply parameter range, the phase A line leaks electricity;

[0035] Determine whether the power supply parameters of phase B are within the standard power supply parameter range;

[0036] When the power supply parameters of the phase B line are within the standard power supply parameter range, the phase B line does not leak electricity; when the power supply parameters of the phase B line are not within the standard power supply parameter range, the phase B line leaks electricity;

[0037] Determine whether the power supply parameters of the phase C line are within the standard power supply parameter range;

[0038] When the power supply parameters of the C-phase line are within the standard power supply parameter range, the C-phase line does not leak electricity; when the power supply parameters of the C-phase line are not within the standard power supply parameter range, the C-phase line leaks electricity.

[0039] Optionally, determining the leakage line segment based on the electric energy parameters includes:

[0040] Determining abnormal power parameters based on power parameters;

[0041] When the power parameters of the i-th line segment to the i+n-th line segment are all abnormal, it is determined that the line segment with leakage is the i-th line segment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG1 is a schematic structural diagram of a device for locating leakage current in a low-voltage power grid area according to an embodiment of the present application;

[0043] FIG2 is a schematic structural diagram of a transformer detection module provided according to an embodiment of the present application;

[0044] FIG3 is a schematic structural diagram of a line detection module provided according to an embodiment of the present application;

[0045] FIG4 is a flow chart of a first method for locating leakage current in a low-voltage area line of a power grid according to an embodiment of the present application;

[0046] FIG5 is a flow chart of a second method for locating leakage current in a low-voltage area line of a power grid according to an embodiment of the present application;

[0047] FIG6 is a flow chart of a third method for locating leakage current in a low-voltage area line of a power grid according to an embodiment of the present application;

[0048] FIG7 is a flow chart of a fourth method for locating leakage current in a low-voltage substation area of ​​a power grid provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0050] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the application described herein can be practiced in orders other than those illustrated or described herein.

[0051] FIG1 is a schematic diagram of a structure of a low-voltage power grid line leakage locating device provided according to an embodiment of the present application. As shown in FIG1 , the low-voltage power grid line leakage locating device includes:

[0052] Control module 13, transformer detection module 11 and line detection module 12;

[0053] The transformer detection module 11 is electrically connected to the control module 13 and is configured to detect whether there is a current signal in the transformer and input the current signal to the control module 13;

[0054] The control module 13 is communicatively connected to the line detection module 12, and is configured to determine whether the transformer is leaking electricity based on the current signal and output a line detection signal to the line detection module 12 when the transformer is leaking electricity, so as to control the line detection module 12 to detect the electrical energy parameters of the line corresponding to the transformer; and determine the line section with leakage based on the electrical energy parameters.

[0055] The transformer detection module 11 is configured to detect whether the transformer has leakage anomalies. In the power system, the substation refers to the range and area supplied by a transformer. Each substation may include a transformer detection module 11 to detect in real time whether the transformer has leakage anomalies. The transformer detection module 11 can be set on the neutral line of the transformer. When the transformer is operating normally, the vector sum of the current flowing through the neutral line of the transformer is zero; when the transformer has leakage anomalies, the vector sum of the current on the neutral line of the transformer is not zero. By utilizing the properties of the neutral line, the transformer detection module 11 is set on the neutral line. When a current signal is detected on the neutral line of the transformer, it indicates that the transformer has leakage anomalies at this time. Therefore, the control module 13 outputs a line detection signal to the line detection module 12 to detect all lines of the transformer with leakage.

[0056] The line detection module 12 is configured to detect leakage in the corresponding lines within the transformer, thereby locating the transformer leakage to the line segment on the transformer. The line detection module 12 may include an energy meter, which is installed on each line segment to detect the energy parameters of the line segment, including current, voltage drop to ground, and power. Because a leaking line will have a lower voltage drop to ground and an increased power, determining the specific line segment with a leakage by determining the energy parameters of each line segment can be used.

[0057] Optionally, the transformer detection module 11 is used to detect whether there is a current signal on the neutral line of the transformer. When there is a current signal on the neutral line of the transformer, the current signal is input into the control module 13 through the transformer detection module 11. The control module 13 then determines that the transformer has a leakage abnormality and outputs a line detection signal to the line detection module 12. The line detection module 12 detects the electrical energy parameters of the line of the leaking transformer, and the control module 13 further locates the leaking line section based on the electrical energy parameters.

[0058] The technical solution of the embodiment of the present application is to set a leakage locating device in each transformer substation to detect the leakage condition of each transformer substation in real time, and use the characteristics of the transformer neutral line in combination with the transformer detection module to timely locate the leakage transformer. In the case of transformer leakage, the line detection module is further used to detect which part of the transformer line segment has leakage, and then the leakage area is locked in time, avoiding the problem of large-scale power loss caused by untimely line leakage maintenance, and improving the accuracy of line leakage positioning and the timeliness of personnel maintenance.

[0059] Optionally, FIG2 is a schematic structural diagram of a transformer detection module provided according to an embodiment of the present application. In combination with FIG1 and FIG2 , the transformer detection module 11 includes: a current mutual induction unit 111 and a signal transmission circuit 112;

[0060] The current mutual induction unit 111 is arranged on the neutral line 4 of the transformer and is electrically connected to the signal transmission circuit 112, and is arranged to generate a current signal in the event of a transformer leakage;

[0061] The signal transmission circuit 112 is electrically connected to the control module 13 and is configured to input the current signal into the control module 13 .

[0062] The current mutual induction unit 111 can be used to sense the induced current signal on the neutral line 4. In the event of a transformer leakage anomaly, the vector sum of multiple currents on the neutral line 4 is not zero. The current on the neutral line 4 generates an induced magnetic field in the area where the current mutual induction unit 111 is located. The current mutual induction unit 111 generates a current signal based on the induced magnetic field of the current on the neutral line 4 and transmits the current signal to the signal transmission circuit 112.

[0063] In some embodiments, the current mutual inductance unit 111 includes a magnet 1111 and an induction coil 1112. The magnet 1111 is disposed around the neutral line 4, and the induction coil 1112 is disposed around the magnet 1111 and electrically connected to the signal transmission circuit 112. The induction coil 1112 generates a current signal through the induced magnetic field around the magnet 1111 and transmits the current signal to the signal transmission circuit 112, thereby detecting the neutral line 4.

[0064] In the case where there is no induced magnetic field on the neutral line 4 , there is no current signal in the signal transmission circuit 112 .

[0065] The technical solution in the embodiment of the present application is to set a current mutual induction unit and a signal transmission circuit in the transformer detection module, detect the current flowing through the neutral line in real time through the current mutual induction unit, and use this as a basis for judging the condition of transformer leakage. In the event of transformer leakage, the current signal is promptly transmitted to the control module through the signal transmission circuit, thereby ensuring the timeliness of line leakage detection.

[0066] Optionally, with continued reference to FIG2 , the signal transmission circuit 112 includes: a rectifier bridge 1121 , a unidirectional thyristor 1122 , a trip coil 1123 and a trip switch 1124 ;

[0067] The input end of the rectifier bridge 1121 is connected to the output end of the current mutual inductance unit, and the first output end of the rectifier bridge 1121 is connected to the gate of the unidirectional thyristor 1122;

[0068] The anode of the unidirectional thyristor 1122 is connected to the first input end of the trip coil 1123 , and the cathode of the unidirectional thyristor 1122 is connected to the second input end of the trip coil 1123 ; the second input end of the trip coil 1123 is also connected to the control module 13 through the trip switch 1124 .

[0069] The rectifier bridge 1121 is configured to convert an AC current signal into a DC current signal; the unidirectional thyristor 1122 is configured to be turned on when there is a current signal in the signal transmission circuit 112, and to be turned off when there is no current signal in the signal transmission circuit 112, thereby ensuring the accuracy of the current signal transmission; the trip coil 1123 is configured to be configured such that when there is a current signal in the coil, the armature in the trip coil 1123 is attracted to control the second input end of the trip coil 1123 to be connected to the control module 13, so as to control the current signal to enter the control module 13.

[0070] Optionally, the two ends of the induction coil in the current mutual inductance unit 111 are respectively connected to the two input ends of the rectifier bridge 1121, so that the AC current signal enters the rectifier bridge 1121 and is converted into a DC current signal by the action of the rectifier bridge 1121 and output from the two output ends of the rectifier bridge 1121; the output end of the rectifier bridge 1121 is connected to the gate of the unidirectional thyristor 1122. When the current signal flows into the gate, the unidirectional thyristor 1122 is triggered to turn on, and the current signal can flow into the tripping coil 1123 through the unidirectional thyristor 1122, the tripping coil 1123 is energized and attracted, the tripping switch 1124 is closed, the path between the control module 13 and the tripping coil 1123 is connected, and the current signal enters the control module 13 through the tripping switch 1124.

[0071] When there is no induced magnetic field on the neutral line 4 , there is no current in the signal transmission circuit 112 , the unidirectional thyristor 1122 is non-conductive and in the off state, the armature in the trip coil 1123 is not attracted, and the trip switch 1124 is disconnected.

[0072] The technical solution of the embodiment of the present application is to set a rectifier bridge, a unidirectional thyristor, a trip coil and a trip switch in the signal transmission circuit, so that the signal transmission current can be turned on only when there is a leakage abnormality, so as to transmit the current signal to the control module, thereby improving the accuracy of current signal detection.

[0073] Optionally, FIG3 is a structural diagram of a line detection module provided according to an embodiment of the present application. In combination with FIG3 and FIG1 , the line detection module 12 includes: at least two power detection meters 121;

[0074] The electric energy detection meters 121 are respectively arranged at different positions on the line and are configured to measure the electric energy parameters of different line sections.

[0075] An energy detection meter 121 is provided on the line corresponding to the transformer and is configured to detect the energy parameters on the line. There are at least two energy detection meters 121, each provided at a different position on the line, to obtain energy parameters for different line sections and achieve more accurate positioning of leakage anomalies.

[0076] Exemplarily, the line detection module 12 includes eight power detection meters 121, each of which can detect the power parameters of the three-phase lines A, B, and C, as well as the power parameters of the neutral line. The transformer line includes four poles, and corresponding power detection meters 121 are set at both ends of each pole. The line section is divided into five sections, namely the transformer-pole No. 1 line section, the pole No. 1-pole No. 2 line section, the pole No. 2-pole No. 3 line section, the pole No. 3-pole No. 4 line section, and the line section after the pole No. 4. Correspondingly, the power parameters of the line sections detected by the line detection module 12 include the power parameters of all line sections. When the power parameters of the pole No. 2-pole No. 3 line section, the pole No. 3-pole No. 4 line section, and the line section after the pole No. 4 are abnormal, while the power parameters of the transformer-pole No. 1 line section and the pole No. 1-pole No. 2 line section are normal, it means that there is a leakage abnormality in the pole No. 2-pole No. 3 line section.

[0077] The number of electric energy detection meters 121 can be determined according to the positioning accuracy, and this embodiment of the present application does not limit this.

[0078] In some embodiments, the control module includes a digital-to-analog conversion unit, a display unit, and an early warning unit. The digital-to-analog conversion unit can convert the analog value of the current signal into a digital value and transmit it to the display unit. The display unit then displays leakage information to alert power inspectors of abnormal transformer leakage. The early warning unit can be configured to issue an early warning message to maintenance personnel after receiving the current signal, prompting them to conduct repairs as soon as possible to avoid affecting the operation of the power system.

[0079] FIG4 is a flow chart of a first method for locating a low-voltage power line in a power grid according to an embodiment of the present application. In combination with FIG1 , FIG2 , FIG3 , and FIG4 , an embodiment of the present application further provides a method for locating a low-voltage power line in a power grid. The method is applied to a device for locating a low-voltage power line in a power grid, and includes:

[0080] S10. Acquire current signal.

[0081] The current signal on the neutral line 4 can be obtained according to the transformer detection module 11. The transformer detection module 11 is electrically connected to the control module 13. The transformer detection module 11 is set on the neutral line 4 of the transformer. When the transformer is operating normally, the vector sum of the current flowing through the neutral line 4 of the transformer is zero. When the transformer has a leakage anomaly, the vector sum of the current on the neutral line 4 of the transformer is not zero. When the current signal on the neutral line 4 of the transformer is monitored, it indicates that the transformer has a leakage anomaly, and the current signal is then input into the control module 13.

[0082] S11. Determine whether the transformer has leakage according to the current signal.

[0083] When there is a current signal in the control module 13, the current vector sum on the transformer neutral line 4 is not zero, indicating that there is a leakage abnormality in the transformer at this time; when there is no current signal in the control module 13, the current vector sum on the transformer neutral line 4 is zero, indicating that there is no leakage abnormality in the transformer at this time.

[0084] In some embodiments, it is possible to determine whether the current value in the current signal is zero, thereby determining whether the transformer has a leakage anomaly. The current value in the current signal can represent the vector sum of the currents on the transformer neutral line 4. If the vector sum is not zero, it indicates that a non-zero current signal exists, indicating that the transformer has a leakage anomaly. If the vector sum is zero, the current value of the current signal is also zero, indicating that the transformer does not have a leakage anomaly.

[0085] S12. When it is determined that the transformer is leaking electricity according to the current signal, a line detection signal is output to the line detection module to control the line detection module to detect the electric energy parameters of the line corresponding to the transformer.

[0086] The line detection module 12 is configured to detect leakage in the corresponding line of the transformer, thereby locating the transformer leakage to the line segment on the transformer. The line detection module 12 may include an energy detection meter 121, which is provided on each line segment to detect the energy parameters of the line segment, including current parameters, voltage drop to ground, and power parameters.

[0087] S13. Determine the line section with leakage according to the electric energy parameters.

[0088] Since the voltage drop of the leakage line to the ground will decrease and the power will increase, the specific leakage line section can be determined by judging the power parameters of each line section.

[0089] Optionally, the transformer detection module 11 is used to detect whether there is a current signal on the neutral line 4 of the transformer. When there is a current signal on the neutral line 4 of the transformer, the current signal is input into the control module 13 through the transformer detection module 11. The control module 13 then determines that the transformer has a leakage abnormality and outputs a line detection signal to the line detection module 12. The line detection module 12 detects the electrical energy parameters of the line of the leaking transformer, and the control module 13 further locates the leaking line section based on the electrical energy parameters.

[0090] The technical solution of the embodiment of the present application obtains a current signal and determines whether the transformer has leakage abnormality based on the current signal. When the transformer has leakage abnormality, a line detection signal is output so that the line detection module can detect which part of the transformer line segment has leakage, and then timely lock the leakage area, thereby avoiding the problem of large-scale power loss caused by untimely line leakage inspection and maintenance, and improving the accuracy of line leakage positioning and the timeliness of personnel inspection and maintenance.

[0091] Based on the above embodiment, FIG5 is a flow chart of a second method for locating leakage current in a low-voltage area line of a power grid provided in an embodiment of the present application. In combination with FIG1, FIG2, FIG3 and FIG5, the method includes:

[0092] S20: Acquire current signal.

[0093] S21. Determine whether the transformer has leakage according to the current signal.

[0094] S22. When it is determined that the transformer is leaking electricity according to the current signal, obtain the power supply parameters of the A-phase line, the B-phase line, and the C-phase line of the corresponding transformer.

[0095] The transformer includes phase A, phase B, and phase C lines. When leakage abnormality is detected in the corresponding transformer, the power supply parameters of the multi-phase lines can be first confirmed to be abnormal based on the power supply parameters of the phase A line, the phase B line, and the phase C line.

[0096] S23. Determine whether the phase A line has leakage according to the power supply parameters of the phase A line, determine whether the phase B line has leakage according to the power supply parameters of the phase B line, and determine whether the phase C line has leakage according to the power supply parameters of the phase C line.

[0097] In the event of a leakage on the corresponding line, the power in the line power supply parameters will suddenly increase, the current will increase, and the voltage drop to the ground will decrease. The power supply parameters of phase A, phase B, and phase C can be used to determine which phase has the leakage anomaly.

[0098] S24 . When any phase of the A-phase line, the B-phase line, or the C-phase line leaks electricity, a line detection signal of the corresponding line is output to the line detection module.

[0099] S25. Determine the line section with leakage according to the electric energy parameters.

[0100] For example, assuming that there is a leakage anomaly in the phase A line, first obtain the A-phase line power supply parameters, B-phase line power supply parameters and C-phase line power supply parameters of the corresponding transformer, and judge based on the A-phase line power supply parameters that the power in the A-phase power supply parameters will suddenly increase, the current will become larger and the voltage drop to the ground will decrease, and multiple parameters of the B-phase line power supply parameters are normal. Based on the multiple parameters of the C-phase line power supply parameters being normal, it indicates that there is a leakage anomaly in the phase A line at this time and the detection signal of the phase A line is output to the line detection module 12, so that the line detection module 12 detects the leakage area of ​​the phase A line segment.

[0101] The technical solution of the embodiment of the present application obtains the power supply parameters of the corresponding multi-phase transformer and judges the leakage conditions of the multi-phase according to the power supply parameters of the multi-phase. By first locating the leakage condition of the corresponding line and then further locating the leakage condition of the corresponding line section, it realizes the precise positioning of the leakage anomaly of the transformer line.

[0102] Based on the above embodiment, FIG6 is a flow chart of a third method for locating leakage current in a low-voltage area line of a power grid provided in an embodiment of the present application. In combination with FIG1, FIG2, FIG3 and FIG6, the method includes:

[0103] S30: Acquire a current signal.

[0104] S31. Determine whether the transformer has leakage according to the current signal.

[0105] S32. When it is determined that the transformer is leaking electricity according to the current signal, obtain the power supply parameters of the A-phase line, the B-phase line, and the C-phase line of the corresponding transformer.

[0106] S33, determining whether the power supply parameters of the phase A line are within the standard power supply parameter range;

[0107] When the power supply parameters of phase A are within the standard power supply parameter range, there is no leakage in phase A; when the power supply parameters of phase A are not within the standard power supply parameter range, there is leakage in phase A.

[0108] Determine whether the power supply parameters of phase B are within the standard power supply parameter range;

[0109] When the power supply parameters of the phase B line are within the standard power supply parameter range, the phase B line does not leak electricity; when the power supply parameters of the phase B line are not within the standard power supply parameter range, the phase B line leaks electricity;

[0110] Determine whether the power supply parameters of the phase C line are within the standard power supply parameter range;

[0111] When the power supply parameters of the C-phase line are within the standard power supply parameter range, the C-phase line does not leak electricity; when the power supply parameters of the C-phase line are not within the standard power supply parameter range, the C-phase line leaks electricity.

[0112] The standard power supply parameter range can be a multi-phase parameter range under normal line operation, including a standard power parameter range, a standard current parameter range, and a standard ground voltage drop parameter range. In the event of a line leakage fault, the power parameter will increase, the current parameter will increase, and the ground voltage drop parameter will decrease. By judging whether the power supply parameters of the phase A line, the phase B line, and the phase C line are within the standard power supply parameter range, it can be determined which phase line has the leakage abnormality.

[0113] S33. When any phase of the A-phase line, the B-phase line, and the C-phase line leaks electricity, a line detection signal of the corresponding line is output to the line detection module.

[0114] S35. Determine the line section with leakage according to the electric energy parameters.

[0115] Based on the above embodiment, FIG7 is a flow chart of a fourth method for locating leakage current in a low-voltage area line of a power grid provided in an embodiment of the present application. In combination with FIG1, FIG2, FIG3 and FIG7, the method includes:

[0116] S40: Acquire a current signal.

[0117] S41. Determine whether the transformer has leakage according to the current signal.

[0118] S42. When it is determined that the transformer is leaking electricity according to the current signal, a line detection signal is output to the line detection module to control the line detection module to detect the electric energy parameters of the line corresponding to the transformer.

[0119] S43. Determine abnormal electric energy parameters according to the electric energy parameters.

[0120] Abnormal electrical energy parameters can be power parameters, current parameters, and ground voltage drop parameters. When there is leakage abnormality in the line section, the power parameters will increase, the current parameters will increase, and the ground voltage drop parameters will decrease. This can be used to identify abnormal electrical energy parameters and locate the line section corresponding to the abnormal electrical energy parameters.

[0121] S44 . When the power parameters of the i-th line segment to the i+n-th line segment are all abnormal, determine that the line segment with leakage is the i-th line segment.

[0122] For example, the insulation of the third pole of the phase A line is damaged, resulting in leakage of the external line. The line detection module 12 includes eight electric energy detection meters 121, each of which can detect the electric energy parameters of the three-phase A, B, and C lines, as well as the electric energy parameters of the neutral line. The transformer line includes four poles, and corresponding electric energy detection meters 121 are set at both ends of each pole. The line section is divided into five sections, namely the transformer-first pole line section, the first pole-second pole line section, the second pole-third pole line section, the third pole-fourth pole line section, and the line section after the fourth pole. The electric energy parameters of the phase A line, the phase B line, and the phase C line are obtained, and the electric energy parameters of the phase A line, the phase B line, and the phase C line are compared with the standard power supply parameter range. It is found that the power parameter, current parameter, and ground voltage drop parameter of the phase A line are not within the standard power supply parameter range, and it is determined that there is a leakage anomaly in the phase A line. Output the line detection signal of the phase A line and obtain the power parameters of multiple line sections of the phase A line. If the power parameters of the line section from pole 2 to pole 3, the line section from pole 3 to pole 4, and the line section after pole 4 are abnormal, while the power parameters of the line section from transformer to pole 1 and the line section from pole 1 to pole 2 are normal, it means that there is a leakage abnormality in the line section from pole 2 to pole 3.

[0123] If there is leakage anomaly in the line section, it will also affect the power transmission after the line section, and thus affect the power parameters of the line section and the lines after the line section.

[0124] The technical solution of the embodiment of the present application obtains a current signal and determines whether the transformer has leakage abnormality based on the current signal. When the transformer has leakage abnormality, a line detection signal is output so that the line detection module can detect which part of the transformer line segment has leakage, and then timely lock the leakage area, thereby avoiding the problem of large-scale power loss caused by untimely line leakage inspection and maintenance, and improving the accuracy of line leakage positioning and the timeliness of personnel inspection and maintenance.

Claims

1. A leakage locating device for low-voltage power grid lines, include: Control module, transformer detection module and line detection module; The transformer detection module is electrically connected to the control module and is configured to detect whether there is a current signal in the transformer and input the current signal to the control module; The control module is in communication connection with the line detection module, and is configured to determine whether the transformer is leaking electricity according to the current signal and output a line detection signal to the line detection module when the transformer is leaking electricity, so as to control the line detection module to detect the electric energy parameters of the line corresponding to the transformer; And the line section with leakage is determined according to the electric energy parameters.

2. The device according to claim 1, in, The transformer detection module includes: a current mutual induction unit and a signal transmission circuit; The current mutual inductance unit is arranged on the neutral line of the transformer and is electrically connected to the signal transmission circuit, and is arranged to generate a current signal in the event of a current leakage in the transformer; The signal transmission circuit is electrically connected to the control module and is configured to input the current signal into the control module.

3. The device according to claim 2, in, The current mutual inductance unit comprises: a magnet and an induction coil; The magnet is disposed around the neutral line, and the induction coil is disposed around the magnet and is electrically connected to the signal transmission circuit.

4. The device according to claim 2, in, The signal transmission circuit comprises: a rectifier bridge, a unidirectional thyristor, a tripping coil and a tripping switch; The input end of the rectifier bridge is connected to the output end of the current mutual inductance unit, and the first output end of the rectifier bridge is connected to the gate of the unidirectional thyristor; The anode of the unidirectional thyristor is connected to the first input end of the tripping coil, and the cathode of the unidirectional thyristor is connected to the second input end of the tripping coil; the second input end of the tripping coil is also connected to the control module through the tripping switch.

5. The device according to claim 1, in, The line detection module includes: at least two electric energy detection meters; The electric energy detection meters are respectively arranged at different positions on the line, and are configured to measure the electric energy parameters of different line sections.

6. A method for locating leakage current in a low-voltage power grid area line, applied in the device described in any one of claims 1 to 5, include: Acquire current signal; determining whether the transformer has leakage according to the current signal; When it is determined that the transformer is leaking electricity according to the current signal, a line detection signal is output to a line detection module to control the line detection module to detect the electric energy parameters of the line corresponding to the transformer; The line section with leakage is determined according to the electric energy parameter.

7. The method according to claim 6, in, Judging whether the transformer has leakage according to the current signal includes: It is determined whether the current value in the current signal is 0.

8. The method according to claim 6, in, Outputting line detection signals to the line detection module, including: Obtaining A-phase line power supply parameters, B-phase line power supply parameters and C-phase line power supply parameters corresponding to the transformer; According to the power supply parameters of the A phase line, it is determined whether the A phase line has leakage, according to the power supply parameters of the B phase line, it is determined whether the B phase line has leakage, and according to the power supply parameters of the C phase line, it is determined whether the C phase line has leakage. Leakage; In the case that any one of the A-phase line, the B-phase line and the C-phase line has a leakage, a line detection signal of the corresponding line is output to the line detection module.

9. The method according to claim 8, in, Judging whether the A phase line has leakage according to the A phase line power supply parameter, judging whether the B phase line has leakage according to the B phase line power supply parameter, and judging whether the C phase line has leakage according to the C phase line power supply parameter, includes: Determine whether the power supply parameters of the phase A line are within the standard power supply parameter range; When the power supply parameters of the A-phase line are within the standard power supply parameter range, the A-phase line does not leak electricity; when the power supply parameters of the A-phase line are not within the standard power supply parameter range, the A-phase line leaks electricity; Determine whether the power supply parameters of the B-phase line are within the standard power supply parameter range; When the power supply parameters of the B-phase line are within the standard power supply parameter range, the B-phase line does not leak electricity; when the power supply parameters of the B-phase line are not within the standard power supply parameter range, the B-phase line leaks electricity; Determine whether the power supply parameters of the C-phase line are within the standard power supply parameter range; When the power supply parameters of the C-phase line are within the standard power supply parameter range, the C-phase line has no leakage; when the power supply parameters of the C-phase line are not within the standard power supply parameter range, the C-phase line has leakage.

10. The method according to claim 6, in, Determining the line segment with leakage according to the electric energy parameter includes: Determining abnormal electric energy parameters according to the electric energy parameters; When the electric energy parameters of the i-th line segment to the i+n-th line segment are all abnormal, it is determined that the line segment with leakage is the i-th line segment.

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