Distribution line short-circuit fault processing device using voltage and current time sequence information

Abstract

The invention provides a distribution line short-circuit fault processing device using voltage and current time sequence information. A distribution line short-circuit fault processing device utilizing voltage and current time sequence information is applied to a distribution line, a plurality of measuring points are arranged on the distribution line, each measuring point is provided with a circuit breaker, and the distribution line short-circuit fault processing device utilizing the voltage and current time sequence information is arranged on the measuring points. The distribution line short-circuit fault processing device using the voltage and current time sequence information comprises a calculation module, a first fault detection module, a first control module, a second fault detection module, a second control module, a third fault detection module, a fourth fault detection module, a fifth fault detection module and a third control module. According to the distribution line short-circuit fault processing device based on the voltage and current time sequence information, the requirements of rapid power supply recovery of an instantaneous fault and accurate isolation of a permanent fault can be met.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a distribution line short-circuit fault processing device using voltage and current time series information. Background Art

[0002] The power system includes power generation, transmission, distribution and consumption. Among them, the power grid that receives electricity from the transmission network and supplies and distributes electricity to various users step by step is called the distribution network.

[0003] In the related art, when the distribution network detects a fault in the distribution line, it will quickly isolate and recover the transient fault in the faulty section. Since it is difficult to distinguish whether the fault is a transient fault or a permanent fault, it is difficult to meet the requirements of accurate isolation of permanent faults. Summary of the invention

[0004] The present application aims to solve one of the technical problems existing in the prior art or related technology.

[0005] To this end, the present application proposes a distribution line short-circuit fault processing device using voltage and current time series information.

[0006] In view of this, according to the present application, a distribution line short-circuit fault processing device using voltage and current time series information is proposed, which is applied to the distribution line. A plurality of measuring points are arranged on the distribution line, and a circuit breaker is arranged on each measuring point. The distribution line short-circuit fault processing device using voltage and current time series information is arranged on the measuring point. The distribution line short-circuit fault processing device using voltage and current time series information includes: A calculation module, used to determine the effective value of current and the effective value of voltage at the measuring point; A first fault detection module, configured to determine that a current measurement point is a power supply side measurement point when a current effective value is greater than a current threshold value and exceeds a first time duration, and the power supply side measurement point is located on a power supply side of a fault section; A first control module, connected to the first fault detection module, is used to control the first circuit breaker to disconnect when the first fault detection module determines that the current measurement point is the power side measurement point, and delay for a second time to control the first circuit breaker to reclose, and the first circuit breaker is located at the power side measurement point of the fault section; A second fault detection module is used to determine whether the effective value of the current is less than or equal to the current threshold after the first circuit breaker is reclosed, and when the effective value of the current is less than or equal to the current threshold, determine that the fault type is a transient fault; when the effective value of the current is greater than the current threshold after the first circuit breaker is reclosed, determine that the fault type is a permanent fault; A second control module is connected to the second fault detection module and is used to control the first circuit breaker to disconnect again when the second fault detection module determines that the fault type is a permanent fault; The third fault detection module is used to detect the relationship between the effective value of the current and the current threshold, and the numerical relationship between the effective value of the voltage and the voltage threshold. When the effective value of the current is not greater than the current threshold and the effective value of the voltage is less than the voltage threshold, it is determined that the current measurement point is a load side measurement point, and the load side measurement point is located on the load side of the fault point; The fourth fault detection module is used to start timing until the three-phase voltage disappears to obtain a third time length when the third fault detection module detects that the voltage effective value is less than the voltage threshold; detect whether the third time length is within a preset time window, and when the third time length is within the preset time window, determine that the current measurement point is a load-side measurement point of the fault section; a fifth fault detection module, after the fourth fault detection module determines that the current measurement point is the load-side measurement point of the fault section, detecting whether the three-phase voltage loss is detected again after a fourth time period, the fourth time period being the sum of the reclosing action time and the re-disconnection time of the first circuit breaker of the power supply side measurement point, and determining that the fault type is a permanent fault if the three-phase voltage loss is detected after the fourth time period; The third control module is connected to the fifth fault detection module. The third control module is used to control the second circuit breaker to disconnect when the fifth fault detection module determines that the fault type is a permanent fault. The second circuit breaker is a load-side circuit breaker of the fault section.

[0007] In this technical solution, multiple measuring points are set on the distribution line, and the multiple measuring points divide the distribution line into multiple sections to be tested. Each measuring point on the distribution line is provided with a measuring device and a circuit breaker. Therefore, a power supply side circuit breaker is provided on the power supply side of each section to be tested, and a load side circuit breaker is provided on the load side of each section to be tested. The measuring device can obtain the current and voltage information of the section to be tested. A distribution line short-circuit fault processing device using voltage and current time series information is provided at the measuring point on the distribution line.

[0008] The distribution line short-circuit fault processing device using voltage and current time series information includes a calculation module, a first fault detection module, a first control module, a second fault detection module, a second control module, a third fault detection module, a fourth fault detection module, a fifth fault detection module and a third control module. Among them, the first fault detection module, the first control module, the second fault detection module and the second control module are used to locate the power supply side measurement point on the power supply side of the fault section, and control the first circuit breaker at the power supply side measurement point. The third fault detection module, the fourth fault detection module, the fifth fault detection module and the third control module are used to locate the load side measurement point on the power supply side of the fault section, and control the second circuit breaker at the load side measurement point, so that when the fault section is in a transient fault, the distribution line can quickly restore power supply, and when the fault section is in a permanent fault, the fault section can be isolated.

[0009] The following is a detailed description of each module: The numerical relationship between the effective current value and the current threshold is compared through the first fault detection module. When the effective current value is greater than the current threshold and lasts for more than a first time, it is determined that the measurement point where the first fault detection module is located is located on the power supply side of the fault section, that is, the current measurement point is the power supply side measurement point of the fault section.

[0010] When it is detected that the effective current value is greater than the current threshold, the first fault detection module starts timing. After the effective current value is greater than the current threshold for more than a first time period, it is determined that the measurement point of the first fault detection module is located at the power supply side of the fault section.

[0011] The first control module is controlled by the first fault detection module, and the first control module is used to control the action of the first circuit breaker. When the first fault detection module detects that the current measurement point is located at the power supply side of the fault section, the first control module controls the first circuit breaker to act and disconnect the first circuit breaker. After controlling the first circuit breaker to disconnect for a second time period, the first circuit breaker is controlled to reclose.

[0012] The fault type of the fault point is determined by the second fault detection module. After the first circuit breaker is reclosed, the second fault detection module compares the numerical relationship between the effective value of the current and the current threshold. If the comparison result is that the effective value of the current is less than or equal to the current threshold, it is determined that the fault of the fault point has been cleared, and at this time, the fault type of the fault point is determined to be a transient fault. If the comparison result is that the effective value of the current is greater than the current threshold, it is determined that the fault of the fault point still exists, and the fault type of the fault point is determined to be a permanent fault.

[0013] The second control module is controlled by the second fault detection module. The second control module is used to control the action of the first circuit breaker. When the second fault detection module detects that the fault type is a permanent fault, it is determined that the fault section needs to be isolated at this time. Therefore, the second control module controls the first circuit breaker to disconnect again.

[0014] The third fault detection module can compare the numerical relationship between the effective value of the current and the current threshold, and the numerical relationship between the effective value of the voltage and the voltage threshold. When the effective value of the current is not greater than the current threshold, and the effective value of the voltage is less than the voltage threshold, it is determined that the measurement point where the third fault detection module is located is located on the load side of the fault point.

[0015] The fourth fault detection module is connected to the third fault detection module. The fourth fault detection module further determines the positional relationship between the current measurement point and the fault section based on the detection result of the third fault detection module. Specifically, when the third fault detection module detects that the effective value of the voltage is less than the voltage threshold, the moment when the effective value of the voltage is less than the voltage threshold is used as the timing starting point, and the moment when the three-phase voltage disappears is used as the timing end point. The third time length is obtained by timing, and the fourth fault detection module determines whether the third time length is within the preset time window. If the third time length is within the preset time window, the current measurement point is determined to be the load side measurement point of the fault section.

[0016] The fifth fault detection module is connected to the fourth fault detection module, and the fifth fault detection module further determines the fault type based on the detection result of the fourth fault detection module. Specifically, after the fourth fault detection module detects that the current measurement point is the load-side measurement point of the fault section, the timing starts. After the timing reaches the fourth time length, it is determined whether the three-phase voltage loss is detected again. If the three-phase voltage loss is detected again, it is determined that the first circuit breaker on the power supply side of the fault section is disconnected again, and the fault type is determined to be a permanent fault. It should be noted that the fourth time length is the sum of the reclosing action time and the re-disconnection time of the measurement point on the power supply side. Therefore, after the timing reaches the fourth time length, the three-phase voltage loss is detected again, and it is determined that the first circuit breaker at the measurement point on the power supply side is disconnected again after the reclosing.

[0017] The third control module is controlled by the fifth fault detection module. The third control module is used to control the second circuit breaker located at the load side measuring point of the fault section to be disconnected when the fifth fault detection module determines that the fault type is a permanent fault. Since the first circuit breaker is disconnected again after reclosing, the second circuit breaker is controlled by the third control module to be disconnected. At this time, both the first circuit breaker and the second circuit breaker are in a disconnected state, and the fault section in a permanent fault is isolated.

[0018] In the technical solution of the present application, the effective value of current and the effective value of voltage are determined based on the current and voltage information collected by the measuring device. The power supply side measurement point of the fault section is located according to the duration of the effective value of current being greater than the current threshold, and after the first circuit breaker at the power supply side measurement point is controlled to disconnect, the reclosing is delayed for the first time. If the fault in the fault section disappears after reclosing, the fault is determined to be a transient fault, and the power supply to the fault section has been restored at this time. If the fault in the fault section still exists after reclosing, the fault type is determined to be a permanent fault, and at this time, the first circuit breaker is quickly disconnected again. When it is detected that the effective value of voltage is less than the voltage threshold, it is determined that the measurement point is located on the load side of the fault point, and the timing is started until the first three-phase voltage loss is detected. When the third time length obtained by timing is within the preset time window, the measurement point is determined to be the load side measurement point of the fault section, and the positioning of the load side measurement point of the fault section is completed. If the three-phase voltage loss is detected again within the fourth time period, the fault section is determined to be a permanent fault. At this time, the second circuit breaker at the load side measurement point of the fault section is controlled to be disconnected again to isolate the permanent fault. The distribution line short-circuit fault processing device using voltage and current time series information in this application can meet the needs of rapid power restoration of transient faults and accurate isolation of permanent faults.

[0019] In some technical solutions, the preset time window is the sum of the first duration and the action duration of the first circuit breaker.

[0020] In the technical solution of the present application, after the power supply side measurement point detects that the effective current value is continuously greater than the current threshold value for more than the first time period, the first circuit breaker is controlled to disconnect. Therefore, the load side measurement point of the fault section will detect the three-phase voltage loss at the load side measurement point after the first time period plus the first circuit breaker action time period after the effective voltage value is detected to be less than the voltage threshold. Therefore, the preset time window is set to the sum of the first time period and the action time period of the first circuit breaker, so that whether the measurement point is the load side measurement point of the fault section can be detected based on whether the third time period is within the preset time window.

[0021] In the technical solution of the present application, by setting the preset time window to the sum of the first time length and the opening time window of the first circuit breaker, it is possible to ensure that the complete opening information of the circuit breaker on the power supply side can be obtained within the judgment time limit, thereby further improving the accuracy of short-circuit fault judgment.

[0022] In some technical solutions, multiple measurement points correspond to multiple first time lengths, and the first time lengths corresponding to the measurement points close to the end of the power supply increase step by step to the measurement points close to the beginning of the power supply.

[0023] In this technical solution, a plurality of measuring points are arranged in the power distribution line, and a corresponding first duration is arranged for each measuring point. The first duration is arranged according to the principle of increasing step by step from the end of the power supply to the beginning of the power supply, so the first duration corresponding to the measuring point close to the end of the power supply to the measuring point close to the beginning of the power supply increases step by step.

[0024] In the technical solution of the present application, since the distance between each measurement point and the power supply is different, the first time length corresponding to each measurement point is set based on the positional relationship between the measurement point and the power supply, thereby improving the accuracy of locating the measurement point on the power supply side to determine whether the measurement point is a fault section.

[0025] In some technical solutions, a measuring device is provided at the measuring point, and the measuring device is used to collect the current measurement value and the voltage measurement value; The distribution line short circuit fault processing device using voltage and current time series information also includes: A sampling module, used to obtain the current measurement value and the voltage measurement value collected by the measuring device; The calculation module is used to calculate the effective value of the current and the effective value of the voltage according to the current measurement value and the voltage measurement value.

[0026] In this technical solution, the distribution line short-circuit fault processing device using voltage and current time series information also includes a sampling module, which is connected to the calculation module. The sampling module is connected to the measuring device at the measuring point, and the sampling module can obtain the current measurement value and the voltage measurement value collected by the measuring device. The sampling module transmits the obtained current measurement value and voltage measurement value to the calculation module, and the calculation module can calculate the current effective value and the voltage effective value based on the current measurement value and the voltage measurement value.

[0027] In the technical solution of the present application, a measuring device is set at the measuring point of the distribution line, and the current measurement value and voltage measurement value collected by the measuring device are obtained by a sampling module in a distribution line short-circuit fault processing device that utilizes the voltage and current time series information, thereby improving the accuracy of the current effective value and voltage effective value calculated by the calculation module.

[0028] In some technical solutions, the distribution line short circuit fault processing device using voltage and current time series information also includes: A power supply module is connected to the computing module, the first fault detection module, the first control module, the second fault detection module, the second control module, the third fault detection module, the fourth fault detection module, the fifth fault detection module, the third control module and the sampling module, and the power supply module is used to supply power to the computing module, the first fault detection module, the first control module, the second fault detection module, the second control module, the third fault detection module, the fourth fault detection module, the fifth fault detection module, the third control module and the sampling module.

[0029] In the technical solution of the present application, the power supply module can supply power to each module in the distribution line short circuit fault processing device using voltage and current time series information, thereby ensuring the operating stability of the distribution line short circuit fault processing device using voltage and current time series information.

[0030] In some solutions, the measurement points are located on poles outside the substation.

[0031] Additional aspects and advantages of the present application will become apparent in the following description or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 A structural block diagram of a distribution line short-circuit fault processing device using voltage and current time series information provided in some embodiments of the present application is shown; Figure 2 One of the schematic diagrams of an overhead power distribution line provided in some embodiments of the present application is shown; Figure 3 A second schematic diagram of an overhead power distribution line provided in some embodiments of the present application is shown; Figure 4 One of the switch timing diagrams of a transient fault in some embodiments of the present application is shown; Figure 5 One of the switch timing diagrams of permanent faults in some embodiments of the present application is shown; Figure 6 The second switching timing diagram of a transient fault in some embodiments of the present application is shown; Figure 7 The second switching timing diagram of a permanent fault in some embodiments of the present application is shown; Figure 8 A schematic diagram of the on-off state of a switch in some embodiments of the present application is shown; Fig. 9 A schematic diagram of the on-off state of a switch with a permanent fault in some embodiments of the present application is shown.

[0033] Figure 1 and Figure 2 The reference numerals in the figures are as follows: 1000 A distribution line short-circuit fault processing device using voltage and current time series information, 1001 a calculation module, 1002 a first fault detection module, 1003 a first control module, 1004 a second fault detection module, 1005 a second control module, 1006 a third fault detection module, 1007 a fourth fault detection module, 1008 a fifth fault detection module, 1009 a third control module, 1010 a sampling module, 1011 a power supply module, 200 a distribution line, 202 a measuring point, 204 a measuring device, and 206 a circuit breaker. DETAILED DESCRIPTION

[0034] In order to more clearly understand the above-mentioned objectives, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, in the absence of conflict, the present embodiment and the features in the embodiment can be combined with each other.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0036] Refer to the following Figures 1 to 9 A distribution line short circuit fault processing device using voltage and current time series information according to some embodiments of the present application is described.

[0037] According to one embodiment of the present application, Figure 1 A structural block diagram of a distribution line short-circuit fault processing device using voltage and current time series information provided in some embodiments of the present application is shown. Figure 2 Schematic diagrams of power distribution lines provided in some embodiments of the present application are shown, such as Figure 1 and Figure 2 As shown, a distribution line short-circuit fault processing device 1000 using voltage and current time series information is proposed and applied to a distribution line 200. A plurality of measuring points 202 are arranged on the distribution line 200. A circuit breaker 206 is arranged on each measuring point 202. The distribution line short-circuit fault processing device 1000 using voltage and current time series information is arranged on the measuring point 202.

[0038] The distribution line short circuit fault processing device 1000 using voltage and current time series information includes: A calculation module 1001 is used to determine the effective value of current and the effective value of voltage at a measurement point; A first fault detection module 1002, configured to determine that the current measurement point is a power supply side measurement point when the effective current value is greater than a current threshold value and exceeds a first time period, and the power supply side measurement point is located at the power supply side of the fault section; The first control module 1003 is connected to the first fault detection module 1002, and is used to control the first circuit breaker to disconnect when the first fault detection module 1002 determines that the current measurement point is the power side measurement point, and delay for a second time to control the first circuit breaker to reclose, and the first circuit breaker is located at the power side measurement point of the fault section; The second fault detection module 1004 is used to determine whether the effective value of the current is less than or equal to the current threshold after the first circuit breaker is reclosed, and when the effective value of the current is less than or equal to the current threshold, determine that the fault type is a transient fault; when the effective value of the current is greater than the current threshold after the first circuit breaker is reclosed, determine that the fault type is a permanent fault; The second control module 1005 is connected to the second fault detection module 1004 and is used to control the first circuit breaker to disconnect again when the second fault detection module 1004 determines that the fault type is a permanent fault; The third fault detection module 1006 is used to detect the relationship between the effective value of the current and the current threshold, and the numerical relationship between the effective value of the voltage and the voltage threshold. When the effective value of the current is not greater than the current threshold and the effective value of the voltage is less than the voltage threshold, it is determined that the current measurement point is a load-side measurement point, and the load-side measurement point is located on the load side of the fault point. The fourth fault detection module 1007 is used to start timing until the three-phase voltage disappears to obtain a third time length when the third fault detection module 1006 detects that the voltage effective value is less than the voltage threshold; detect whether the third time length is within a preset time window, and when the third time length is within the preset time window, determine that the current measurement point is a load-side measurement point of the fault section; The fifth fault detection module 1008 detects whether the three-phase voltage loss is detected again after the fourth fault detection module 1007 determines that the current measurement point is the load-side measurement point of the fault section after the fourth time period has passed, and the fourth time period is the sum of the reclosing action time and the re-disconnection time of the first circuit breaker at the power supply side measurement point. If the three-phase voltage loss is detected after the fourth time period, it is determined that the fault type is a permanent fault; The third control module 1009 is connected to the fifth fault detection module 1008. The third control module 1009 is used to control the second circuit breaker to disconnect when the fifth fault detection module 1008 determines that the fault type is a permanent fault. The second circuit breaker is a load-side circuit breaker of the fault section.

[0039] In this embodiment, a plurality of measuring points are set on the distribution line, and the plurality of measuring points divide the distribution line into a plurality of sections to be tested. A measuring device 204 and a circuit breaker 206 are set on each measuring point on the distribution line. Therefore, a power supply side circuit breaker is set on the power supply side of each section to be tested, and a load side circuit breaker is set on the load side of each section to be tested. The measuring device can obtain the current and voltage information of the section to be tested. A distribution line short circuit fault processing device 1000 using voltage and current time series information is set on the measuring point on the distribution line.

[0040] The distribution line short circuit fault processing device 1000 using voltage and current time series information includes a calculation module 1001, a first fault detection module 1002, a first control module 1003, a second fault detection module 1004, a second control module 1005, a third fault detection module 1006, a fourth fault detection module 1007, a fifth fault detection module 1008 and a third control module 1009. The first fault detection module 1002, the first control module 1003, the second fault detection module 1004 and the second control module 1005 are used to locate the power supply side measurement point on the power supply side of the fault section, and control the first circuit breaker at the power supply side measurement point. The third fault detection module 1006, the fourth fault detection module 1007, the fifth fault detection module 1008 and the third control module 1009 are used to locate the load-side measurement point on the power supply side of the fault section, and to control the second circuit breaker at the load-side measurement point, so that when the fault section is in a transient fault, the distribution line can quickly restore power supply, and when the fault section is in a permanent fault, the fault section can be isolated.

[0041] The following is a detailed description of each module: The first fault detection module 1002 compares the numerical relationship between the current effective value and the current threshold. When the current effective value is greater than the current threshold and lasts for more than a first time period, it is determined that the measurement point where the first fault detection module 1002 is located is on the power supply side of the fault point, that is, the current measurement point is the power supply side measurement point.

[0042] Exemplarily, the following relation (1) is used as a criterion for determining whether the first fault detection module 1002 is started: ; (1) in, , , is the effective value of current, is the current threshold, and the current threshold is the current setting value obtained by adjustment.

[0043] When it is detected that the effective current value is greater than the current threshold, the first fault detection module 1002 starts timing. After the effective current value is greater than the current threshold for a first period of time, it is determined that the measurement point of the first fault detection module 1002 is located at the power supply side of the fault section.

[0044] The first control module 1003 is controlled by the first fault detection module 1002, and is used to control the action of the first circuit breaker. When the first fault detection module 1002 detects that the current measurement point is located at the power supply side of the fault section, the first control module 1003 controls the first circuit breaker to act so that the first circuit breaker is disconnected, and after controlling the first circuit breaker to be disconnected for a second time period, controls the first circuit breaker to reclose.

[0045] The fault type of the fault point is determined by the second fault detection module 1004. After the first circuit breaker is reclosed, the second fault detection module 1004 compares the numerical relationship between the effective value of the current and the current threshold. If the comparison result is that the effective value of the current is less than or equal to the current threshold, it is determined that the fault of the fault point has been cleared, and at this time, the fault type of the fault point is determined to be a transient fault. If the comparison result is that the effective value of the current is greater than the current threshold, it is determined that the fault of the fault point still exists, and the fault type of the fault point is determined to be a permanent fault.

[0046] The second control module 1005 is controlled by the second fault detection module 1004. The second control module 1005 is used to control the action of the first circuit breaker. When the second fault detection module 1004 detects that the fault type is a permanent fault, it is determined that the fault section needs to be isolated at this time. Therefore, the second control module 1005 controls the first circuit breaker to disconnect again.

[0047] The third fault detection module 1006 can compare the numerical relationship between the effective value of the current and the current threshold, and the numerical relationship between the effective value of the voltage and the voltage threshold. When the effective value of the current is not greater than the current threshold, and the effective value of the voltage is less than the voltage threshold, it is determined that the measurement point where the third fault detection module 1006 is located is located on the load side of the fault point.

[0048] For example, when the voltage effective value satisfies the following relation (2), it is determined that the current measurement point is located on the load side of the fault point: ; (2) in, , , is the effective value of voltage, is the voltage threshold, and the voltage threshold is the voltage setting value obtained by adjustment.

[0049] The fourth fault detection module 1007 is connected to the third fault detection module 1006. The fourth fault detection module 1007 further determines the positional relationship between the current measurement point and the fault section based on the detection result of the third fault detection module 1006. Specifically, when the third fault detection module 1006 detects that the effective value of the voltage is less than the voltage threshold, the moment when the effective value of the voltage is less than the voltage threshold is used as the timing starting point, and the moment when the three-phase voltage disappears is used as the timing end point for timing. The third duration is obtained by timing, and the fourth fault detection module 1007 determines whether the third duration is within the preset time window. If the third duration is within the preset time window, the current measurement point is determined to be the load side measurement point of the fault section.

[0050] The fifth fault detection module 1008 is connected to the fourth fault detection module 1007. The fifth fault detection module 1008 further determines the fault type based on the detection result of the fourth fault detection module 1007. Specifically, after the fourth fault detection module 1007 detects that the current measurement point is the load side measurement point of the fault section, the timing starts. After the timing reaches the fourth time length, it is determined whether the three-phase voltage loss is detected again. If the three-phase voltage loss is detected again, it is determined that the first circuit breaker on the power supply side of the fault section is disconnected again, and the fault type is determined to be a permanent fault. It should be noted that the fourth time length is the sum of the reclosing action time and the re-disconnection time of the measurement point on the power supply side. Therefore, after the timing reaches the fourth time length, the three-phase voltage loss is detected again, and it is determined that the first circuit breaker at the measurement point on the power supply side is disconnected again after the reclosing.

[0051] The third control module 1009 is controlled by the fifth fault detection module 1008. The third control module 1009 is used to control the second circuit breaker located at the load side measuring point of the fault section to be disconnected when the fifth fault detection module 1008 determines that the fault type is a permanent fault. Since the first circuit breaker is disconnected again after reclosing, the second circuit breaker is controlled by the third control module 1009 to be disconnected. At this time, the first circuit breaker and the second circuit breaker are both in the disconnected state, and the fault section in the permanent fault is isolated.

[0052] In the technical solution of the present application, the effective value of current and the effective value of voltage are determined based on the current and voltage information collected by the measuring device. The power supply side measurement point of the fault section is located according to the duration of the effective value of current being greater than the current threshold, and after the first circuit breaker at the power supply side measurement point is controlled to disconnect, the reclosing is delayed for the first time. If the fault in the fault section disappears after reclosing, the fault is determined to be a transient fault, and the power supply to the fault section has been restored at this time. If the fault in the fault section still exists after reclosing, the fault type is determined to be a permanent fault, and at this time, the first circuit breaker is quickly disconnected again. When it is detected that the effective value of voltage is less than the voltage threshold, it is determined that the measurement point is located on the load side of the fault point, and the timing is started until the first three-phase voltage loss is detected. When the third time length obtained by timing is within the preset time window, the measurement point is determined to be the load side measurement point of the fault section, and the positioning of the load side measurement point of the fault section is completed. If the three-phase voltage loss is detected again within the fourth time period, the fault section is determined to be a permanent fault. At this time, the second circuit breaker at the load side measurement point of the fault section is controlled to be disconnected again to isolate the permanent fault. The distribution line short-circuit fault processing device using voltage and current time series information in this application can meet the needs of rapid power restoration of transient faults and accurate isolation of permanent faults.

[0053] In some embodiments, optionally, the preset time window is the sum of the first duration and the action duration of the first circuit breaker.

[0054] In the embodiment of the present application, since the first circuit breaker is controlled to disconnect after the effective current value is detected to be continuously greater than the current threshold value for more than the first time period at the power supply side measurement point, the load side measurement point of the fault section will detect the three-phase voltage loss at the load side measurement point after the first time period plus the action time period of the first circuit breaker after the effective voltage value is detected to be less than the voltage threshold value. Therefore, the preset time window is set to the sum of the first time period and the action time period of the first circuit breaker, so that whether the measurement point is the load side measurement point of the fault section can be detected based on whether the third time period is within the preset time window.

[0055] For example, the preset time window is expressed by the following equation (3): t3=t1+t0;(3) Among them, t3 is the preset time window, t1 is the first duration, and t0 is the action duration of the first circuit breaker.

[0056] Exemplarily, the first duration is set to 1s, the action duration of the first circuit breaker is 0.1s, and the preset time window corresponding to the load side measurement point is set to 1.1s, which is slightly longer than the opening time of the first circuit breaker, to ensure that complete opening information can be obtained within the load side judgment time limit.

[0057] In the embodiment of the present application, by setting the preset time window to the sum of the first time length and the opening time window of the first circuit breaker, it can be ensured that the complete opening information of the circuit breaker on the power supply side can be obtained within the judgment time limit, thereby further improving the accuracy of short-circuit fault judgment.

[0058] In some embodiments, optionally, multiple measurement points correspond to multiple first time lengths, and the first time lengths corresponding to the measurement points close to the end of the power supply increase step by step to the measurement points close to the beginning of the power supply.

[0059] In this embodiment, a plurality of measuring points are arranged in the power distribution line, and a corresponding first duration is arranged for each measuring point. The first duration is arranged according to the principle of increasing step by step from the end of the power supply to the beginning of the power supply, so the first duration corresponding to the measuring point close to the end of the power supply to the measuring point close to the beginning of the power supply increases step by step.

[0060] In the embodiment of the present application, since the distance between each measurement point and the power supply is different, the first time length corresponding to each measurement point is set based on the positional relationship between the measurement point and the power supply, thereby improving the accuracy of locating the measurement point on the power supply side to determine whether the measurement point is a fault section.

[0061] In some embodiments, optionally, a measuring device is provided at the measuring point, and the measuring device is used to collect current measurement values ​​and voltage measurement values; The distribution line short circuit fault processing device using voltage and current time series information also includes: The sampling module 1010 is used to obtain the current measurement value and the voltage measurement value collected by the measuring device; The calculation module 1001 is used to calculate the effective value of the current and the effective value of the voltage according to the current measurement value and the voltage measurement value.

[0062] In this embodiment, the distribution line short circuit fault processing device using voltage and current time series information also includes a sampling module 1010, and the sampling module 1010 is connected to the calculation module 1001. The sampling module 1010 is connected to the measuring device at the measuring point, and the sampling module 1010 can obtain the current measurement value and the voltage measurement value collected by the measuring device. The sampling module 1010 transmits the obtained current measurement value and voltage measurement value to the calculation module 1001, and the calculation module 1001 can calculate the current effective value and the voltage effective value based on the current measurement value and the voltage measurement value.

[0063] In the embodiment of the present application, a measuring device is set at a measuring point of a distribution line, and the sampling module 1010 in a distribution line short-circuit fault processing device using voltage and current time series information obtains the current measurement value and the voltage measurement value collected by the measuring device, thereby improving the accuracy of the current effective value and the voltage effective value calculated by the calculation module 1001.

[0064] In some embodiments, optionally, the distribution line short circuit fault processing device using voltage and current time series information further includes: The power supply module 1011 is connected to the computing module 1001, the first fault detection module 1002, the first control module 1003, the second fault detection module 1004, the second control module 1005, the third fault detection module 1006, the fourth fault detection module 1007, the fifth fault detection module 1008, the third control module 1009 and the sampling module 1010. The power supply module 1011 is used to supply power to the computing module 1001, the first fault detection module 1002, the first control module 1003, the second fault detection module 1004, the second control module 1005, the third fault detection module 1006, the fourth fault detection module 1007, the fifth fault detection module 1008, the third control module 1009 and the sampling module 1010.

[0065] In the embodiment of the present application, the power supply module 1011 can supply power to each module in the distribution line short circuit fault processing device using voltage and current time series information, thereby ensuring the operating stability of the distribution line short circuit fault processing device using voltage and current time series information.

[0066] In some embodiments, the measurement point is optionally located on a pole outside the substation.

[0067] Figure 3 FIG. 2 shows a second schematic diagram of an overhead power distribution line provided in some embodiments of the present application, such as Figure 3 As shown, in some specific embodiments, the distribution line includes three sections to be tested, which are section 1, section 2 and section 3, respectively. The first circuit breaker and the second circuit breaker at both ends of section 1 are switch 1 and switch 2, respectively. The first circuit breaker and the second circuit breaker at both ends of section 2 are switch 2 and switch 3, respectively. The first circuit breaker and the second circuit breaker at both ends of section 3 are switch 3 and switch 4, respectively.

[0068] Take the case of a BC two-phase short circuit fault in a distribution system with non-effectively grounded neutral point in the section to be tested as an example, as follows: A two-phase short circuit fault occurs at a point on section 2. After the fault, the BC current at switches 1 and 2 increases, and the BC voltage at switches 3 and 4 decreases. The measured current values ​​of the BC current at switches 1 and 2 are greater than the current threshold, satisfying the power supply side startup criteria and timing, and preparing for the exit trip. The effective value of the BC voltage at switches 1 and 2 is also less than the voltage threshold, but the current criterion takes precedence, so the voltage criterion is not started. The BC current at switches 3 and 4 in section 3 decreases and is not greater than the current threshold, while the BC voltage is less than the voltage threshold. The voltage criterion is started and timing is used to determine the faulty section. The exit tripping time delay at switch 2 is the shortest, and it operates 0.2s after the fault occurs. When switch 2 is opened, the fault is isolated from the power supply side, the current at switches 1 and 2 decreases, and the voltage recovers. At this time, for switch 1, the effective value of the current decreases to less than the current threshold within the 0.3s export action time delay, so it returns to normal at 0.2s. At switch 3, it is detected that the effective value of the voltage is less than the second voltage threshold, and with the occurrence of the fault as the starting time, the voltage and current disappear within the time window of 0.1s after the protection delay of the opposite end, and it is judged that the fault section is in section 2. At switch 4, the condition that the fault section is within this section is that the opposite end trips at the export at 0.1s, but in fact the opposite end trips at the export at 0.2s, so it is judged that the fault is not in the protected section 3, so it has returned at 0.1s.

[0069] Figure 4 One of the switch timing diagrams of transient faults in some embodiments of the present application is shown, such as Figure 4 As shown, when the fault in section 2 is transient, after switch 2 is disconnected, after a closing time delay of 1s, the protection closes switch 2. Switch 3 detects incoming power, and the three-phase voltage effective values ​​meet the judgment criteria that they are all greater than the voltage threshold, and the voltage appears, and it is judged that the opposite end is closed. When it is a transient fault, after switch 2 is closed, the power supply is restored, and switch 3 detects incoming power, and it is judged that the fault is transient, and the lock does not act.

[0070] Figure 5 One of the switch timing diagrams of permanent faults in some embodiments of the present application is shown, such as Figure 5 As shown, when section 2 is in a permanent fault, after switch 2 is disconnected, after a closing time delay of 1s, the protection closes switch 2. Switch 3 detects incoming call, and the three-phase voltage effective values ​​are all greater than the voltage threshold to meet the incoming call judgment criteria. The voltage appears and it is judged that the opposite end is closed. When it is a permanent fault, the protection action is accelerated after the switch 2 is closed. Switch 2 trips again without delay. Switch 3 detects power failure, and the three-phase voltage effective values ​​are all less than the second voltage threshold. It is judged that the opposite end trips and the fault is a permanent fault. Switch 3 successively operates the outlet trip.

[0071] Take the case of a single-phase short circuit fault of phase A in a neutral point effectively grounded distribution system as an example for explanation, as follows: A phase short circuit fault occurs at a point on section 2. After the fault, the current of phase A at switch 1 and switch 2 increases, and the voltage of phase A at switch 3 and switch 4 decreases. The effective value of the current of phase A at switch 1 and switch 2 is greater than the current threshold, which meets the power supply side start criterion and timing, and is ready to trip the output. The effective voltage of phases BC at switch 1 and switch 2 is also less than the voltage threshold, but the current criterion takes precedence, so the voltage criterion does not start; the current of phase A at switch 3 and switch 4 decreases and is not greater than the current threshold, while the effective value of the voltage of phase A is less than the voltage threshold, and the voltage criterion starts and timing is used to determine the fault section. The output tripping time delay at switch 2 is the shortest, and it acts 0.2s after the fault occurs. Switch 2 is opened, the fault is isolated from the power supply side, the current at switches 1 and 2 decreases, and the voltage recovers. At this time, for switch 1, the effective value of the current decreases less than the effective value of the current within the 0.3s export action time delay, so it returns to normal at 0.2s; the effective value of the voltage detected at switch 3 is less than the second voltage threshold, and with the occurrence of the fault as the starting time, the voltage and current disappear within the circuit breaker action time window of 0.1s after the opposite end protection delay. It is judged that the fault section is in this section, and permanent and instantaneous fault isolation is prepared; and switch 4 judges that the fault section is in this section on the condition that the opposite end trips at the 0.1s export, but in fact the opposite end trips at the 0.2s export, and it is judged that the fault is not in the protected section, so it has returned at 0.1s.

[0072] In case of a transient fault, after switch 2 is disconnected, after a closing time delay of 1s, the protection closes switch 2. Switch 3 detects incoming power, and the three-phase voltage effective values ​​meet the judgment criteria, which are greater than the voltage threshold. The voltage appears, and the opposite end is judged to be closed. In case of a transient fault, after switch 2 is closed, the power supply is restored, and switch 3 detects incoming power. It is judged that the fault is a transient fault, and the lock does not act.

[0073] In the case of a permanent fault, after switch 2 is disconnected, after a 1s delay in closing time, the protection closes switch 2. Switch 3 detects incoming call, and the three-phase voltage effective values ​​are all greater than the voltage threshold to meet the incoming call judgment criteria. The voltage appears and it is judged that the opposite end is closed. When it is a permanent fault, the protection action is accelerated after the switch 2 is closed. Switch 2 trips again without delay. Switch 3 detects power failure, and the three-phase voltage effective values ​​are all less than the second voltage threshold. It is judged that the opposite end trips and the fault is a permanent fault. Switch 3 successively operates the outlet tripping.

[0074] A short circuit fault occurs at a point on section 3. After the fault, the current at switch 1, switch 2, and switch 3 increases, and the voltage at switch 4 decreases. The current measurement values ​​at switch 1, switch 2, and switch 3 are greater than the current threshold, and timing is performed to prepare for the exit trip. The voltage at switch 1, switch 2, and switch 3 is also less than the voltage threshold, but the current judgment takes precedence, so the voltage judgment does not start; the current at switch 4 decreases and is not greater than the current threshold, while the voltage is less than the voltage threshold, so the voltage judgment starts and timing is performed to determine the fault section. The exit tripping time delay at switch 3 is the shortest, and it operates 0.1s after the fault occurs. Switch 3 is opened, the fault is isolated from the power supply side, the current at switch 1, switch 2, and switch 3 decreases, and the voltage is restored; the power failure, voltage and current at switch 4 are detected to disappear, and the start time is the fault occurrence, and the voltage and current disappear within the time window after the opposite end protection delay, and it is judged that the fault section is in section 3, and permanent fault isolation is prepared.

[0075] Figure 6 The second switching timing diagram of a transient fault in some embodiments of the present application is shown. Figure 7 The second switch timing diagram of a permanent fault in some embodiments of the present application is shown. After the switch 3 is disconnected, after a period of delay, such as 1 second, the protection closes the switch 3. The switch 4 detects the incoming call, the voltage and current appear, and it is judged that the opposite end is closed. If it is a permanent fault, the protection action is accelerated after the switch 3 is closed, and the switch 3 is tripped again without delay. The switch 4 detects the power failure, and the opposite end is judged to be tripped. The fault is a permanent fault, and the switch 4 successively trips the outlet; if it is a transient fault, after the switch 3 is closed, the power supply is restored, the switch 4 detects the incoming call, and it is judged that the fault is a transient fault, and the lock does not act.

[0076] Figure 8 Schematic diagram of the switch on-off state of a transient fault in some embodiments of the present application is shown, such as Figure 8 As shown, the circuit breakers at each measuring point on the distribution line include switch PU1, switch PU2, switch PU3, switch PU4 and switch PU5. After the fault is detected, the power supply side circuit breaker of the fault section is located as switch PU3 based on the first time length. After the second time length is delayed, switch PU3 is controlled to reclose. After reclosing, the fault disappears, and the fault type of the fault section is determined to be a transient fault.

[0077] Fig. 9 Schematic diagram of the on-off state of a switch with a permanent fault in some embodiments of the present application is shown. Fig. 9As shown, the circuit breakers at each measuring point on the distribution line include switch PU1, switch PU2, switch PU3, switch PU4 and switch PU5. After the fault is detected, the power supply side circuit breaker of the fault section is located as switch PU3 based on the first time length. After the second time length is delayed, switch PU3 is controlled to reclose. If the fault does not disappear after reclosing, PU3 is controlled to disconnect again. Based on the third time length corresponding to the three-phase voltage loss caused by the first disconnection of PU3, PU4 is located as the load side circuit breaker of the fault section, that is, the section between PU3 and PU4 is the fault section. After PU4 detects the three-phase voltage loss again after the fourth time length is delayed, it is determined that the fault type of the fault section is a permanent fault, and PU4 is controlled to disconnect to isolate the fault section.

[0078] It should be clarified that in the claims, specification and drawings of the present application, the term "multiple" refers to two or more than two. Unless otherwise clearly defined, the orientation or position relationship indicated by the terms "upper" and "lower" is based on the orientation or position relationship shown in the drawings, which is only for the purpose of more conveniently describing the present application and making the description process easier, rather than indicating or implying that the device or element referred to must have the specific orientation described, be constructed and operated in a specific orientation, so these descriptions cannot be understood as limitations on the present application; the terms "connect", "install", "fix" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection between multiple objects, or a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects, or an indirect connection between multiple objects through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood based on the specific circumstances of the above data.

[0079] In the claims, specification and drawings of the present application, the description of the terms "one embodiment", "some embodiments", "specific embodiments" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the claims, specification and drawings of the present application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0080] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A distribution line short circuit fault processing device using voltage and current time series information, characterized in that: Applied to a distribution line, the distribution line is provided with a plurality of measuring points, each measuring point is provided with a circuit breaker, the distribution line short-circuit fault processing device using voltage and current time series information is provided at the measuring point, and the distribution line short-circuit fault processing device using voltage and current time series information comprises: A calculation module, used to determine the effective value of the current and the effective value of the voltage at the measuring point; A first fault detection module, configured to determine that a current measurement point is a power supply side measurement point when the effective value of the current is greater than a current threshold value and exceeds a first time duration, and the power supply side measurement point is located on the power supply side of the fault section; A first control module, connected to the first fault detection module, is used to control the first circuit breaker to disconnect when the first fault detection module determines that the current measurement point is the power side measurement point, and delay for a second time to control the first circuit breaker to reclose, and the first circuit breaker is located at the power side measurement point of the fault section; a second fault detection module, configured to determine whether the effective value of the current is less than or equal to the current threshold after the first circuit breaker is reclosed, and to determine that the fault type is a transient fault when the effective value of the current is less than or equal to the current threshold; and to determine that the fault type is a permanent fault when the effective value of the current is greater than the current threshold after the first circuit breaker is reclosed; A second control module, connected to the second fault detection module, for controlling the first circuit breaker to disconnect again when the second fault detection module determines that the fault type is a permanent fault; a third fault detection module, configured to detect a relationship between the effective value of the current and the current threshold, and a numerical relationship between the effective value of the voltage and the voltage threshold, and to determine that a current measurement point is a load-side measurement point when the effective value of the current is not greater than the current threshold and the effective value of the voltage is less than the voltage threshold, and the load-side measurement point is located on the load side of the fault point; A fourth fault detection module is used to start timing until the three-phase voltage disappears to obtain a third time length when the third fault detection module detects that the voltage effective value is less than the voltage threshold; detect whether the third time length is within a preset time window, and when the third time length is within the preset time window, determine that the current measurement point is a load-side measurement point of the fault section; a fifth fault detection module, after the fourth fault detection module determines that the current measurement point is the load-side measurement point of the fault section, detecting whether the three-phase voltage loss is detected again after a fourth time period, wherein the fourth time period is the sum of the reclosing action time and the re-disconnection time of the first circuit breaker of the power-side measurement point, and determining that the fault type is a permanent fault if the three-phase voltage loss is detected after the fourth time period; The third control module is connected to the fifth fault detection module. The third control module is used to control the second circuit breaker to disconnect when the fifth fault detection module determines that the fault type is a permanent fault. The second circuit breaker is a load side circuit breaker of the fault section.

2. The distribution line short circuit fault processing device using voltage and current time series information according to claim 1, characterized in that: The preset time window is the sum of the first duration and the action duration of the first circuit breaker.

3. The distribution line short-circuit fault processing device using voltage and current time series information according to claim 1, characterized in that: The plurality of measurement points correspond to the plurality of first time lengths, and the first time length corresponding to the measurement point close to the end of the power source increases step by step to the measurement point close to the beginning of the power source.

4. The distribution line short-circuit fault processing device using voltage and current time series information according to any one of claims 1 to 3, characterized in that: The measuring point is provided with a measuring device, and the measuring device is used to collect current measurement values ​​and voltage measurement values; The distribution line short circuit fault processing device using voltage and current time series information also includes: A sampling module, used to obtain the current measurement value and the voltage measurement value collected by the measuring device; The calculation module is used to calculate the current effective value and the voltage effective value according to the current measurement value and the voltage measurement value.

5. The distribution line short-circuit fault processing device using voltage and current time series information according to claim 4, characterized in that: Also includes: A power supply module is connected to the computing module, the first fault detection module, the first control module, the second fault detection module, the second control module, the third fault detection module, the fourth fault detection module, the fifth fault detection module, the third control module and the sampling module, and the power supply module is used to power the computing module, the first fault detection module, the first control module, the second fault detection module, the second control module, the third fault detection module, the fourth fault detection module, the fifth fault detection module, the third control module and the sampling module.

6. The distribution line short-circuit fault processing device using voltage and current time series information according to any one of claims 1 to 3, characterized in that: The measuring points are located on poles outside the substation.

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