Power distribution line short fault processing device using voltage and current time series information

Abstract

The application provides a power distribution line short-circuit fault processing device using voltage and current time sequence information. The power distribution line short-circuit fault processing device using voltage and current time sequence information is applied to a power distribution line, a plurality of measuring points are arranged on the power distribution line, a circuit breaker is arranged on each measuring point, and the power distribution line short-circuit fault processing device using voltage and current time sequence information is arranged on the measuring point. The power distribution line short-circuit fault processing device using 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. The power distribution line short-circuit fault processing device using voltage and current time sequence information can meet the requirements of instantaneous fault rapid recovery and permanent fault accurate isolation.

Description

TECHNICAL FIELD

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

[0002] A power system includes power generation, power transmission, power distribution and power consumption, etc. The power grid that receives power from the power transmission grid and supplies and distributes power to various types of users step by step is the power distribution grid.

[0003] In the related art, when the power distribution grid detects that there is a fault in the power distribution line, the transient fault existing in the fault section is quickly isolated and quickly recovered. Since it is difficult to distinguish whether the fault is a transient fault or a permanent fault, it is difficult to meet the requirement of accurate isolation of the permanent fault. SUMMARY

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

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

[0006] Therefore, according to the present application, a power distribution line short-circuit fault processing device using voltage and current time series information is provided, which is applied to a power distribution line, a plurality of measurement points are arranged on the power distribution line, and a circuit breaker is arranged on each measurement point. The power distribution line short-circuit fault processing device using voltage and current time series information is arranged on the measurement point. The power distribution line short-circuit fault processing device using voltage and current time series information comprises:

[0007] A calculation module is configured to determine the current effective value and the voltage effective value at the measurement point.

[0008] A first fault detection module is configured to determine that the current measurement point is a power supply side measurement point when the current effective value is greater than a current threshold value and exceeds a first time length, and the power supply side measurement point is located on the power supply side of the fault section.

[0009] A first control module is connected with the first fault detection module and is configured to control the first circuit breaker to open when the first fault detection module determines that the current measurement point is the power supply side measurement point, and to control the first circuit breaker to reclose after a second time length.

[0010] A second fault detection module is configured to determine whether the current effective value is less than or equal to the current threshold value after the first circuit breaker recloses, and to determine that the fault type is a transient fault when the current effective value is less than or equal to the current threshold value. When the current effective value is greater than the current threshold value after the first circuit breaker recloses, it is determined that the fault type is a permanent fault.

[0011] The second control module is connected with the second fault detection module, and is configured to control the first circuit breaker to be opened again in the case that the second fault detection module determines that the fault type is a permanent fault;

[0012] The third fault detection module is configured to detect the relationship between the current effective value and the current threshold value, and the numerical relationship between the voltage effective value and the voltage threshold value, and determine that the current measurement point is a load-side measurement point located on the load side of the fault point in the case that the current effective value is not greater than the current threshold value and the voltage effective value is less than the voltage threshold value.

[0013] The fourth fault detection module is configured to start timing until the three-phase voltage disappears to obtain a third time length in the case that the third fault detection module detects that the voltage effective value is less than the voltage threshold value, and detect whether the third time length is within a preset time window, and determine that the current measurement point is a load-side measurement point of the fault section when the third time length is within the preset time window.

[0014] The fifth fault detection module is configured to detect whether the three-phase voltage loss is detected again after a fourth time length after the fourth fault detection module determines that the current measurement point is the load-side measurement point of the fault section, the fourth time length being the sum of the reclosing action time and the re-opening time of the power source side measurement point, and determine that the fault type is a permanent fault when the three-phase voltage loss is detected after the fourth time length.

[0015] The third control module is connected with the fifth fault detection module, and the third control module is configured to control the second circuit breaker to be opened in the case that the fifth fault detection module determines that the fault type is a permanent fault, the second circuit breaker being a load-side circuit breaker of the fault section.

[0016] In the technical scheme, a plurality of measurement points are arranged on the power distribution line, and the plurality of measurement points divide the power distribution line into a plurality of to-be-measured sections. The measurement device and the circuit breaker are arranged on each measurement point on the power distribution line. Therefore, the power source side of each to-be-measured section is provided with a power source side circuit breaker, and the load side of each to-be-measured section is provided with a load-side circuit breaker. The measurement device can obtain the current and voltage information of the to-be-measured section. The measurement point on the power distribution line is provided with a power distribution line short-circuit fault processing device using voltage and current time sequence information.

[0017] The power distribution line short circuit fault processing device using voltage and current time series 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. The first fault detection module, the first control module, the second fault detection module and the second control module are used for positioning the power supply side measurement point on the power supply side of the fault section and controlling 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 for positioning the load side measurement point on the power supply side of the fault section and controlling the second circuit breaker at the load side measurement point, so that the power distribution line can quickly restore power supply when the fault section is in transient fault, and the fault section can be isolated when the fault section is in permanent fault.

[0018] The following will be described in detail:

[0019] The first fault detection module compares the numerical relationship between the current effective value and the current threshold value. When the current effective value is greater than the current threshold value and the duration exceeds the first duration, it is determined that the measurement point where the first fault detection module is located is on the power supply side of the fault section, i.e., the current measurement point is the power supply side measurement point of the fault section.

[0020] When the current effective value is detected to be greater than the current threshold value, the first fault detection module starts timing. After the current effective value is greater than the current threshold value for more than the first duration, it is determined that the measurement point where the first fault detection module is located is on the power supply side of the fault section.

[0021] The first control module is controlled by the first fault detection module, and the first control module is used for controlling the action of the first circuit breaker. When the first fault detection module detects that the current measurement point is on the power supply side of the fault section, the first control module controls the first circuit breaker to act, so that the first circuit breaker is opened. After the second duration of controlling the first circuit breaker to be opened, the first circuit breaker is reclosed.

[0022] The second fault detection module judges the fault type of the fault point. After the first circuit breaker is reclosed, the second fault detection module compares the numerical relationship between the current effective value and the current threshold value. In the case that the comparison result is that the current effective value is less than or equal to the current threshold value, it is determined that the fault of the fault point has been cleared, at this time, it is determined that the fault type of the fault point is transient fault. In the case that the comparison result is that the current effective value is greater than the current threshold value, it is determined that the fault of the fault point still exists, and it is determined that the fault type of the fault point is permanent fault.

[0023] The second control module is controlled by the second fault detection module, and the second control module is configured 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, and therefore the second control module controls the first circuit breaker to be opened again.

[0024] The third fault detection module is capable of comparing the numerical relationship between the current effective value and the current threshold value, and the numerical relationship between the voltage effective value and the voltage threshold value. In the case that the current effective value is not greater than the current threshold value, and the voltage effective value is less than the voltage threshold value, it is determined that the measurement point where the third fault detection module is located is on the load side of the fault point.

[0025] The fourth fault detection module is connected with the third fault detection module, and 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, in the case that the third fault detection module detects that the voltage effective value is less than the voltage threshold value, the time when the voltage effective value is less than the voltage threshold value is taken as the starting point of timing, and the time when the three-phase voltage disappears is taken as the ending point of timing. 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, it is determined that the current measurement point is the load side measurement point of the fault section.

[0026] The fifth fault detection module is connected with 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, timing is started. 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 side of the fault section is opened again, and it is determined that the fault type is a permanent fault. It should be noted that the fourth time length is the sum of the reclosing action time and the re-opening time of the measurement point on the power side, and therefore when the three-phase voltage loss is detected again after the timing reaches the fourth time length, it is determined that the first circuit breaker at the measurement point on the power side is opened again after reclosing.

[0027] The third control module is controlled by the fifth fault detection module, and the third control module is configured to control the second circuit breaker at the load side measurement point of the fault section to be opened when the fifth fault detection module determines that the fault type is a permanent fault. Since the first circuit breaker is opened again after reclosing, the second circuit breaker is controlled by the third control module to be opened at this time. At this time, the first circuit breaker and the second circuit breaker are both in the opened state, and the fault section in the permanent fault is isolated.

[0028] In the technical solution of the application, the current effective value and the voltage effective value are determined based on the current and voltage information collected by the measuring device. The power supply side measuring point of the fault section is positioned according to the duration that the current effective value is greater than the current threshold, and after the first circuit breaker at the power supply side measuring point is controlled to be disconnected, reclosing is performed after a first time delay. If the fault of the fault section disappears after reclosing, the fault is determined to be a transient fault, and at this time, the power supply of the fault section has also been restored. If the fault of 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. In the case where the voltage effective value is detected to be less than the voltage threshold, it is determined that the measuring point is located on the load side of the fault point, and timing is started until the first three-phase voltage loss is detected. When the third time duration obtained by timing is within a preset time window, the measuring point is determined to be the load side measuring point of the fault section, and the positioning of the load side measuring point of the fault section is completed. In the case where three-phase voltage loss is detected again within the fourth time duration, the fault section is determined to be a permanent fault, and at this time, the second circuit breaker at the load side measuring point of the fault section is controlled to be disconnected again to isolate the permanent fault. The power distribution line short-circuit fault processing device in the application can meet the needs of fast power restoration for transient faults and accurate isolation for permanent faults.

[0029] In some technical solutions, the preset time window is the sum of the first time duration and the action time duration of the first circuit breaker.

[0030] In the technical solution of the application, after the current effective value is detected to be greater than the current threshold for more than the first time duration at the power supply side measuring point, the first circuit breaker is controlled to be disconnected. Therefore, after the voltage effective value is detected to be less than the voltage threshold for the first time duration plus the action time duration of the first circuit breaker at the load side measuring point of the fault section, three-phase voltage loss of the load side measuring point will be detected. Therefore, the preset time window is set to be the sum of the first time duration and the action time duration of the first circuit breaker, so that whether the measuring point is the load side measuring point of the fault section can be detected based on whether the third time duration is within the preset time duration window.

[0031] In the technical solution of the application, by setting the preset time window to be the sum of the first time duration and the opening time window of the first circuit breaker, complete opening information of the power supply side circuit breaker can be obtained within the judgment time limit, and the accuracy of short-circuit fault judgment is further improved.

[0032] In some technical solutions, the plurality of measuring points correspond to a plurality of first time durations, and the first time durations corresponding to the measuring points from the end near the power supply to the end near the power supply gradually increase.

[0033] In the technical solution, the power distribution line is provided with multiple measurement points, and a corresponding first time length is set for each measurement point. The first time length is set according to the principle that the first time length gradually increases from the end of the power supply to the head of the power supply, so the first time length corresponding to the measurement point close to the end of the power supply gradually increases to the measurement point close to the head of the power supply.

[0034] In the technical solution, the first time length corresponding to each measurement point is set based on the positional relationship between the measurement point and the power supply, because the distance between each measurement point and the power supply is different, thereby improving the accuracy of positioning whether the measurement point is a fault section power supply side measurement point.

[0035] In some technical solutions, the measurement device is arranged on the measurement point, and the measurement device is used to collect current measurement values and voltage measurement values.

[0036] The power distribution line short-circuit fault processing device using voltage and current time series information further comprises:

[0037] The sampling module is used to obtain the current measurement values and voltage measurement values collected by the measurement device.

[0038] The calculation module is used to calculate the current effective value and the voltage effective value based on the current measurement values and the voltage measurement values.

[0039] In the technical solution, the power distribution line short-circuit fault processing device using voltage and current time series information further comprises a sampling module connected with the calculation module. The sampling module is connected with the measurement device at the measurement point, and the sampling module can obtain the current measurement values and voltage measurement values collected by the measurement device. The sampling module transmits the obtained current measurement values and voltage measurement values to the calculation module, and the calculation module can calculate the current effective value and the voltage effective value based on the current measurement values and the voltage measurement values.

[0040] In the technical solution, the measurement device is arranged on the measurement point of the power distribution line, and the sampling module of the power distribution line short-circuit fault processing device using voltage and current time series information is used to obtain the current measurement values and voltage measurement values collected by the measurement device, thereby improving the accuracy of the current effective value and the voltage effective value calculated by the calculation module.

[0041] In some technical solutions, the power distribution line short-circuit fault processing device using voltage and current time series information further comprises:

[0042] The power supply module is connected with the calculation 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 is used for supplying power to the calculation 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.

[0043] In the technical solution of the present application, the power supply module can supply power to each module in the power distribution line short-circuit fault processing device using voltage and current time series information, thereby ensuring the operation stability of the power distribution line short-circuit fault processing device using voltage and current time series information.

[0044] In some technical solutions, the measurement point is located on a column outside the substation.

[0045] Additional aspects and advantages of the present application will become apparent from the following description with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0046] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0047] Figure 1 A structural block diagram of a power distribution line short-circuit fault processing device using voltage and current time series information provided in some embodiments of the present application is shown;

[0048] Figure 2 One of the schematic diagrams of an overhead power distribution line provided in some embodiments of the present application is shown;

[0049] Figure 3 The second schematic diagram of an overhead power distribution line provided in some embodiments of the present application is shown;

[0050] Figure 4 One of the switch timing diagrams of transient faults in some embodiments of the present application is shown;

[0051] Figure 5 One of the switch timing diagrams of permanent faults in some embodiments of the present application is shown;

[0052] Figure 6 The second switch timing diagram of transient faults in some embodiments of the present application is shown;

[0053] Figure 7 The second switch timing diagram of permanent faults in some embodiments of the present application is shown;

[0054] Figure 8 Fig. 1 shows the on-off state of the switch in transient fault in some embodiments of the present application;

[0055] Figure 9 Fig. 2 shows the on-off state of the switch in permanent fault in some embodiments of the present application.

[0056] Figure 1 Fig. 3 shows the on-off state of the switch in transient fault in some embodiments of the present application. Figure 2 The reference signs in Figs. 1-3 are as follows:

[0057] 1000 power distribution line short-circuit fault processing device using voltage and current time series information, 1001 calculation module, 1002 first fault detection module, 1003 first control module, 1004 second fault detection module, 1005 second control module, 1006 third fault detection module, 1007 fourth fault detection module, 1008 fifth fault detection module, 1009 third control module, 1010 sampling module, 1011 power supply module, 200 power distribution line, 202 measurement point, 204 measurement device, 206 circuit breaker. DETAILED DESCRIPTION

[0058] In order to enable a more complete understanding of the above-mentioned objects, features and advantages of the present application, the present application will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the features in the embodiments and the embodiments can be combined with each other without conflict.

[0059] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0060] The power distribution line short-circuit fault processing device using voltage and current time series information according to some embodiments of the present application will be described below with reference to Figures 1 to 9 The power distribution line short-circuit fault processing device using voltage and current time series information according to some embodiments of the present application will be described below with reference to

[0061] According to one embodiment of the present application, Figure 1 Fig. 1 shows the structure block diagram of the power distribution line short-circuit fault processing device using voltage and current time series information provided in some embodiments of the present application, Figure 2 Fig. 2 shows the schematic diagram of the power distribution line provided in some embodiments of the present application, as Figure 1 and Figure 2 As shown in Figs. 1-3, a power distribution line short-circuit fault processing device 1000 using voltage and current time series information is proposed, which is applied to a power distribution line 200, a plurality of measurement points 202 are provided on the power distribution line 200, a circuit breaker 206 is provided on each measurement point 202, and the power distribution line short-circuit fault processing device 1000 using voltage and current time series information is provided on the measurement point 202.

[0062] The power distribution line short-circuit fault processing device 1000 using voltage and current time series information comprises:

[0063] A calculation module 1001 is configured to determine current effective value and voltage effective value at a measurement point;

[0064] A first fault detection module 1002 is configured to determine that the current measurement point is a power supply side measurement point when the current effective value is greater than a current threshold value and exceeds a first time length, and the power supply side measurement point is located on the power supply side of the fault section;

[0065] A first control module 1003 is connected to the first fault detection module 1002 and is configured to control a first circuit breaker to open when the first fault detection module 1002 determines that the current measurement point is the power supply side measurement point, and delay for a second time length and control the first circuit breaker to reclose, and the first circuit breaker is located at the power supply side measurement point of the fault section;

[0066] A second fault detection module 1004 is configured to determine whether the current effective value is less than or equal to the current threshold value after the first circuit breaker recloses, and determine that the fault type is transient fault when the current effective value is less than or equal to the current threshold value; and determine that the fault type is permanent fault when the current effective value is greater than the current threshold value after the first circuit breaker recloses;

[0067] A second control module 1005 is connected to the second fault detection module 1004 and is configured to control the first circuit breaker to open again when the second fault detection module 1004 determines that the fault type is permanent fault;

[0068] A third fault detection module 1006 is configured to detect the relationship between the current effective value and the current threshold value, and the numerical relationship between the voltage effective value and the voltage threshold value, and determine that the current measurement point is a load side measurement point when the current effective value is not greater than the current threshold value and the voltage effective value is less than the voltage threshold value, and the load side measurement point is located on the load side of the fault point;

[0069] A fourth fault detection module 1007 is configured to start timing until 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 value; and detect whether the third time length is within a preset time window, and determine that the current measurement point is the load side measurement point of the fault section when the third time length is within the preset time window;

[0070] The fifth fault detection module 1008 detects whether three-phase voltage loss is detected again after a fourth time period after the fourth fault detection module 1007 determines that the current measurement point is a fault section load side measurement point. The fourth time period is the sum of the first circuit breaker reclosing action time and the re-disconnection time of the power supply side measurement point. If three-phase voltage loss is detected after the fourth time period, it is determined that the fault type is a permanent fault;

[0071] The third control module 1009 is connected with the fifth fault detection module 1008. The third control module 1009 is used to control the second circuit breaker to be disconnected when the fifth fault detection module 1008 determines that the fault type is a permanent fault. The second circuit breaker is a fault section load side circuit breaker.

[0072] In this embodiment, a plurality of measurement points are arranged on the power distribution line, and the plurality of measurement points divide the power distribution line into a plurality of to-be-tested sections. The measurement device 204 and the circuit breaker 206 are arranged on each measurement point on the power distribution line. Therefore, the power supply side of each to-be-tested section is provided with a power supply side circuit breaker, and the load side of each to-be-tested section is provided with a load side circuit breaker. The measurement device can obtain current and voltage information of the to-be-tested section. The measurement point on the power distribution line is provided with the power distribution line short-circuit fault processing device 1000 using voltage and current time sequence information.

[0073] The power distribution line short-circuit fault processing device 1000 using voltage and current time sequence 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. Among them, 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 of 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 of the power supply side of the fault section, and control the second circuit breaker at the load side measurement point. When the fault section is in a transient fault, the power distribution line can be quickly restored to power supply, and when the fault section is in a permanent fault, the fault section can be isolated.

[0074] Each module is described in detail as follows:

[0075] The first fault detection module 1002 compares the numerical relationship between the current effective value and the current threshold value. When the current effective value is greater than the current threshold value and the duration exceeds the first duration, it is determined that the measurement point of the first fault detection module 1002 is located on the power supply side of the fault point, that is, the current measurement point is the power supply side measurement point.

[0076] For example, the following relationship (1) is used as the criterion for determining whether the first fault detection module 1002 is started:

[0077] (1)

[0078] Wherein, , , is the current effective value, is the current threshold value, which is the current setting value obtained by setting.

[0079] When the current effective value is greater than the current threshold value, the first fault detection module 1002 starts timing. When the current effective value is greater than the current threshold value for more than the first duration, it is determined that the measurement point of the first fault detection module 1002 is located on the power supply side of the fault section.

[0080] The first control module 1003 is controlled by the first fault detection module 1002, and the first control module 1003 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 on 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 opened. After a second duration of controlling the first circuit breaker to be opened, the first circuit breaker is reclosed.

[0081] The second fault detection module 1004 judges the fault type of the fault point. After the first circuit breaker is reclosed, the second fault detection module 1004 compares the numerical relationship between the current effective value and the current threshold value. When the comparison result is that the current effective value is less than or equal to the current threshold value, it is determined that the fault of the fault point has been cleared. At this time, it is determined that the fault type of the fault point is transient fault. When the comparison result is that the current effective value is greater than the current threshold value, it is determined that the fault of the fault point still exists, and it is determined that the fault type of the fault point is permanent fault.

[0082] The second control module 1005 is controlled by the second fault detection module 1004, and 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 permanent fault, it is determined that the fault section needs to be isolated at this time, and therefore the second control module 1005 controls the first circuit breaker to be opened again.

[0083] The third fault detection module 1006 can compare the numerical relationship between the current effective value and the current threshold value, and the numerical relationship between the voltage effective value and the voltage threshold value. In the case that the current effective value is not greater than the current threshold value, and the voltage effective value is less than the voltage threshold value, it is determined that the measurement point where the third fault detection module 1006 is located is on the load side of the fault point.

[0084] Exemplarily, in the case that the voltage effective value satisfies the following relationship (2), it is determined that the current measurement point is on the load side of the fault point:

[0085] (2)

[0086] wherein, , , the voltage effective value is V, the voltage threshold value is Vth, and the voltage threshold value is a voltage setting value obtained by setting.

[0087] The fourth fault detection module 1007 is connected with the third fault detection module 1006, and 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, in the case that the third fault detection module 1006 detects that the voltage effective value is less than the voltage threshold value, the time point when the voltage effective value is less than the voltage threshold value is taken as the starting point of timing, and the time point when the three-phase voltage disappears is taken as the ending point of timing. The third time length is obtained by timing, and the fourth fault detection module 1007 judges whether the third time length is within the preset time window. In the case that the third time length is within the preset time window, it is determined that the current measurement point is the load side measurement point of the fault section.

[0088] The fifth fault detection module 1008 is connected with the fourth fault detection module 1007, and 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, timing is started, and after the fourth time length is reached, it is judged 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 side of the fault section is disconnected again, and it is determined that the fault type is a permanent fault. It should be noted that the fourth time length is the sum of the reclosing action time of the measurement point on the power side and the re-disconnection time, so after the fourth time length is reached, the three-phase voltage loss is detected again, it is determined that the first circuit breaker at the measurement point on the power side is disconnected again after reclosing.

[0089] The third control module 1009 is controlled by the fifth fault detection module 1008, and the third control module 1009 is used to control the second circuit breaker at the load side measurement 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.

[0090] In the technical scheme of the present application, the current effective value and the voltage effective value are determined based on the current and voltage information collected by the measurement device. The power side measurement point of the fault section is positioned according to the duration that the current effective value is greater than the current threshold, and the first circuit breaker at the power side measurement point is controlled to be disconnected, and then reclosed after a delay of the first duration. If the fault of the fault section disappears after reclosing, it is determined that the fault is a transient fault, and at this time, the power supply of the fault section has also been restored. If the fault of the fault section still exists after reclosing, it is determined that the fault type is a permanent fault, and at this time, the first circuit breaker is disconnected again. In the case where the voltage effective value is less than the voltage threshold, it is determined that the measurement point is on the load side of the fault point, and timing is started until the first three-phase voltage loss is detected. When the third duration obtained by timing is within the preset time window, it is determined that the measurement point is the load side measurement point of the fault section, and the positioning of the load side measurement point of the fault section is completed. In the case where the three-phase voltage loss occurs again within the fourth duration, it is determined that the fault section is a permanent fault, and 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 power distribution line short-circuit fault processing device in the present application can meet the needs of fast power restoration for transient faults and accurate isolation for permanent faults.

[0091] In some embodiments, optionally, the preset time window is the sum of the first duration and the action duration of the first circuit breaker.

[0092] In the embodiments of the present application, since the first circuit breaker is controlled to be disconnected after the current effective value at the power side measurement point is detected to be greater than the current threshold for more than the first duration, the load side measurement point of the fault section will detect the three-phase voltage loss of the load side measurement point after the first duration plus the action duration of the first circuit breaker after the voltage effective value at the load side measurement point is detected to be less than the voltage threshold. Therefore, the preset time window is set to be the sum of the first duration and the action duration of the first circuit breaker, and whether the measurement point is the load side measurement point of the fault section can be detected based on whether the third duration is within the preset time window.

[0093] Exemplarily, the preset time window is expressed by the following relationship (3):

[0094] t3=t1+t0; (3)

[0095] wherein t3 is a preset time window, t1 is a first time length, and t0 is an action time length of the first circuit breaker.

[0096] For example, the first time length is set to 1s, the action time length of the first circuit breaker is 0.1s, and the preset time window corresponding to the load-side measuring point is set to 1.1s, which is slightly greater than the breaking time of the first circuit breaker, so as to ensure that complete breaking information can be obtained within the judgment time limit.

[0097] In the embodiment of the application, by setting the preset time window to the sum of the first time length and the breaking time window of the first circuit breaker, complete breaking information of the power source-side circuit breaker can be obtained within the judgment time limit, and the accuracy of short-circuit fault judgment is further improved.

[0098] In some embodiments, optionally, the plurality of measuring points correspond to a plurality of first time lengths, and the first time lengths corresponding to the measuring points from the end of the power source to the beginning of the power source gradually increase.

[0099] In this embodiment, a plurality of measuring points are arranged in the distribution line, and a corresponding first time length is arranged for each measuring point. The first time lengths are arranged according to the principle of gradually increasing from the end of the power source to the beginning of the power source, so the first time lengths corresponding to the measuring points from the end of the power source to the beginning of the power source gradually increase.

[0100] In the embodiment of the application, since the distances between each measuring point and the power source are different, the first time length corresponding to each measuring point is set based on the positional relationship between the measuring point and the power source, and the accuracy of positioning whether the measuring point is a power source-side measuring point of the fault section is improved.

[0101] In some embodiments, optionally, a measuring device is arranged on the measuring point, and the measuring device is used to collect current measurement values and voltage measurement values.

[0102] The distribution line short-circuit fault processing device using voltage and current time series information further comprises:

[0103] The sampling module 1010 is configured to obtain current measurement values and voltage measurement values collected by the measuring device.

[0104] The calculation module 1001 is configured to calculate current effective values and voltage effective values according to the current measurement values and the voltage measurement values.

[0105] In the embodiment, the power distribution line short-circuit fault processing device using voltage and current time series information further comprises 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 acquire the current measurement value and the voltage measurement value collected by the measuring device. The sampling module 1010 transmits the acquired 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.

[0106] In the embodiment, the measuring device is arranged at the measuring point of the power distribution line, and the sampling module 1010 of the power distribution line short-circuit fault processing device using voltage and current time series information acquires the current measurement value and the voltage measurement value collected by the measuring device, so that the accuracy of the current effective value and the voltage effective value calculated by the calculation module 1001 is improved.

[0107] In some embodiments, the power distribution line short-circuit fault processing device using voltage and current time series information further comprises:

[0108] The power supply module 1011 is connected to the calculation 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, and the power supply module 1011 is used to supply power to the calculation 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.

[0109] In the embodiment, the power supply module 1011 can supply power to each module in the power distribution line short-circuit fault processing device using voltage and current time series information, so as to ensure the operation stability of the power distribution line short-circuit fault processing device using voltage and current time series information.

[0110] In some embodiments, the measuring point is located on a column outside the transformer substation.

[0111] Figure 3 Fig. 2 shows a schematic diagram of an overhead power distribution line according to some embodiments of the present application, Figure 3As shown, in some embodiments, three to-be-measured sections are included on the power distribution line, the three to-be-measured sections are section 1, section 2 and section 3 respectively, the first circuit breaker and the second circuit breaker at both ends of the section 1 are switch 1 and switch 2 respectively, the first circuit breaker and the second circuit breaker at both ends of the section 2 are switch 2 and switch 3 respectively, and the first circuit breaker and the second circuit breaker at both ends of the section 3 are switch 3 and switch 4 respectively.

[0112] Taking a BC two-phase short-circuit fault of a neutral-point non-effective grounding power distribution system in a to-be-measured section as an example, the following is specifically described:

[0113] A two-phase short-circuit fault occurs at a point on the section 2, after the fault, the BC two-phase current at the switch 1 and the switch 2 increases, and the BC two-phase voltage at the switch 3 and the switch 4 decreases. The measured value of the BC two-phase current at the switch 1 and the switch 2 is greater than the current threshold, the power supply side starting criterion is met, and timing is performed, and the outlet is prepared to trip. The effective value of the BC two-phase voltage at the switch 1 and the switch 2 is also less than the voltage threshold, but the current criterion is prior, and therefore the voltage criterion does not start. The BC two-phase current at the switch 3 and the switch 4 of the section 3 decreases and is not greater than the current threshold, and the BC two-phase voltage is less than the voltage threshold, the voltage criterion starts and timing is performed to judge the fault section. The outlet trip time delay of the switch 2 is the shortest, and the switch 2 acts after 0.2s of the fault occurrence. The switch 2 is opened, the fault is isolated from the power supply side, the current at the switch 1 and the switch 2 decreases, and the voltage recovers. At this time, for the switch 1, the effective value of the current decreases and is less than the current threshold within the outlet action time delay of 0.3s, so the switch 1 returns at 0.2s. The switch 3 detects that the effective value of the voltage is less than the second voltage threshold, and the voltage and the current disappear within the time window of 0.1s after the protection delay time from the fault occurrence, and it is judged that the fault section is in the section 2. The switch 4 judges that the fault section is in the section, and the condition is that the opposite end trips at 0.1s, but actually the opposite end trips at 0.2s, and it is judged that the fault is not in the protected section 3, and therefore the switch 4 returns at 0.1s.

[0114] Figure 4 One of the switch timing diagrams of the transient fault in some embodiments of the application is shown as follows: Figure 4 As shown, when the section 2 is a transient fault, after the switch 2 is opened, the protection closes the switch 2 after a closing time delay of 1s. The switch 3 detects incoming power, meets the criterion that the effective value of the three-phase voltage is greater than the voltage threshold, and the voltage appears, and judges that the opposite end is closed. When it is a transient fault, after the switch 2 is closed, the power supply recovers, the switch 3 detects incoming power, judges that the fault is a transient fault, and the closing does not act.

[0115] Figure 5 One of the switch timing diagrams of the permanent fault in some embodiments of the application is shown as follows: Figure 5As shown, when the section 2 is a permanent fault, after the switch 2 is opened, the protection closes the switch 2 after a closing time delay of 1s. The switch 3 detects incoming power, meets the incoming power criterion that the effective values of three-phase voltages are all greater than the voltage threshold, the voltage appears, and it is judged that the opposite end is closed. When it is a permanent fault, after the switch 2 is closed, the protection acts quickly, the switch 2 is opened again without time delay, the switch 3 detects loss of power, the effective values of three-phase voltages are all less than the second voltage threshold, it is judged that the opposite end is tripped, the fault is a permanent fault, and the switch 3 acts in sequence to trip the outlet.

[0116] Taking an A-phase single-phase short-circuit fault in a neutral-point effective grounding power distribution system as an example, the following is specifically described:

[0117] An A-phase short-circuit fault occurs at the point in the section 2. After the fault, the A-phase currents at the switches 1 and 2 increase, and the A-phase and B-phase voltages at the switches 3 and 4 decrease. The effective values of the A-phase currents at the switches 1 and 2 are greater than the current threshold, the power supply side starting criterion is met, and timing is performed, and the outlet is prepared to trip. The effective voltages of the B and C phases at the switches 1 and 2 are also less than the voltage threshold, but the current criterion is prior, so the voltage criterion does not start; the A-phase currents at the switches 3 and 4 decrease and are not greater than the current threshold, and the effective values of the A-phase voltages are less than the voltage threshold, the voltage criterion starts and timing is performed to judge the fault section. The outlet tripping time delay of the switch 2 is the shortest, and the switch 2 acts after 0.2s of the fault. The switch 2 is opened, the fault is isolated from the power supply side, the currents at the switches 1 and 2 decrease, and the voltages recover. At this time, for the switch 1, the effective value of the current decreases and is less than the effective value of the current within the outlet action time delay of 0.3s, so it returns at 0.2s. The switch 3 detects that the effective values of the voltages are all less than the second voltage threshold, and the voltages and currents disappear within the breaker action time window of 0.1s after the time delay of the opposite end protection from the start of the fault, it is judged that the fault section is in the section, and the permanent and transient fault isolation is prepared; and the switch 4 judges that the fault section is in the section, and the opposite end trips at 0.1s, but actually the opposite end trips at 0.2s, so it is judged that the fault is not in the protected section, and therefore it returns at 0.1s.

[0118] When it is a transient fault, after the switch 2 is opened, the protection closes the switch 2 after a closing time delay of 1s. The switch 3 detects incoming power, meets the criterion that the effective values of three-phase voltages are all greater than the voltage threshold, the voltage appears, and it is judged that the opposite end is closed. When it is a transient fault, after the switch 2 is closed, the power supply recovers, the switch 3 detects incoming power, it is judged that the fault is a transient fault, and the action is blocked.

[0119] When it is a permanent fault, the switch 2 is opened, and after a closing time delay of 1s, the protection closes the switch 2. The incoming power is detected at the switch 3, and the incoming power criterion is met, that is, the effective values of three-phase voltages are all greater than the voltage threshold value, the voltage appears, and it is judged that the opposite end is closed. When it is a permanent fault, the switch 2 is closed after the accelerated protection action, the switch 2 is opened again without time delay, the loss of power is detected at the switch 3, the effective values of three-phase voltages are all less than the second voltage threshold value, it is judged that the opposite end is tripped, the fault is a permanent fault, and the switch 3 is sequentially acted on the outlet tripping.

[0120] A short-circuit fault occurs at the point on the section 3. After the fault, the currents at the switches 1, 2 and 3 increase, and the voltage at the switch 4 decreases. The current measurement values at the switches 1, 2 and 3 are greater than the current threshold value, and the time is counted, and the outlet tripping is prepared. The voltages at the switches 1, 2 and 3 are also less than the voltage threshold value, but the current criterion is prior, and therefore the voltage criterion is not started; the current at the switch 4 decreases and is not greater than the current threshold value, and the voltage is less than the voltage threshold value, the voltage criterion is started and the time is counted to judge the fault section. The outlet tripping time delay of the switch 3 is the shortest, and the switch 3 is acted on after 0.1s of the fault occurrence. The switch 3 is opened, the fault is isolated from the power supply side, the currents at the switches 1, 2 and 3 decrease, and the voltage recovers; the loss of power is detected at the switch 4, the voltage and current disappear, and the time window after the fault occurrence is taken as the starting time, the voltage and current disappear within the time window after the opposite end protection delay, it is judged that the fault section is in the section 3, and the permanent fault isolation is prepared.

[0121] Figure 6 Fig. 2 shows a switch timing diagram of a transient fault in some embodiments of the present application, Figure 7 Fig. 3 shows a switch timing diagram of a permanent fault in some embodiments of the present application. After the switch 3 is opened, the protection closes the switch 3 after a time delay, such as 1s. The incoming power is detected at the switch 4, the voltage and current appear, and it is judged that the opposite end is closed. If it is a permanent fault, the switch 3 is closed after the accelerated protection action, the switch 3 is opened again without time delay, the loss of power is detected at the switch 4, it is judged that the opposite end is tripped, the fault is a permanent fault, and the switch 4 is sequentially acted on the outlet tripping; if it is a transient fault, the power supply recovers after the switch 3 is closed, the incoming power is detected at the switch 4, it is judged that the fault is a transient fault, and the action is blocked.

[0122] Figure 8 Fig. 4 shows a switch on-off state diagram of a transient fault in some embodiments of the present application, as shown in Figure 8 The circuit breakers at each measurement point on the power distribution line include the switches PU1, PU2, PU3, PU4 and PU5. After the fault is detected, the power supply side circuit breaker of the fault section is located to the switch PU3 based on the first time length, and after a delay of the second time length, the switch PU3 is controlled to reclose. After the reclosing, the fault disappears, and it is determined that the fault type of the fault section is a transient fault.

[0123] Figure 9 The switch on-off state diagram of permanent fault in some embodiments of the present application is shown as follows: Figure 9 As shown, the circuit breakers at each measurement point on the power distribution line include switch PU1, switch PU2, switch PU3, switch PU4 and switch PU5. After detecting the fault, the power source side circuit breaker located to the fault section based on the first time length is switch PU3, and after delaying for the second time length, the control controls switch PU3 to reclose, and after reclosing, if the fault does not disappear, the control controls PU3 to open again. The third time length corresponding to the three-phase voltage loss generated by the first opening of PU3 locates PU4 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 delaying for the fourth time length, it is determined that the fault type of the fault section is permanent fault, and PU4 is controlled to open to isolate the fault section.

[0124] It should be noted that in the claims, the specification and the drawings of the present application, the term "a plurality of" means two or more, unless otherwise specifically defined, and the terms "upper", "lower", and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only used to more conveniently describe the present application and make the description process more simple, and therefore these descriptions cannot be understood as limiting the present application; the terms "connection", "installation", "fixation" and the like should be understood in a broad sense, for example, "connection" can be fixed connection between objects, or detachable connection between objects, or integral connection; can be direct connection between objects, or indirect connection between objects through intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances of the above data.

[0125] In the claims, the specification and the drawings of the present application, the description of the terms "one embodiment", "some embodiments", "a specific embodiment" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the claims, the specification and the drawings of the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0126] The above merely provides preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A short-circuit fault handling device for power distribution lines utilizing voltage and current time series information, characterized in that, This device is applied to power distribution lines, wherein multiple measurement points are set on the power distribution lines, and a circuit breaker is installed at each measurement point. A power distribution line short-circuit fault handling device utilizing voltage and current time series information is installed at each measurement point. The power distribution line short-circuit fault handling device utilizing voltage and current time series information includes: The calculation module is used to determine the effective values ​​of the current and voltage at the measurement point; The first fault detection module is used to determine that the current measurement point is a power supply side measurement point when the effective value of the current is greater than the current threshold and exceeds a first time period. The power supply side measurement point is located on the power supply side of the fault section. The first control module is connected to the first fault detection module. When the first fault detection module determines that the current measurement point is a power supply side measurement point, it controls the first circuit breaker to open and delays for a second duration to control the first circuit breaker to reclose. The first circuit breaker is located at the power supply side measurement point in the fault section. The 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. When the effective value of the current is less than or equal to the current threshold, the fault type is determined to be a transient fault. When the effective value of the current is greater than the current threshold after the first circuit breaker is reclosed, the fault type is determined to be a permanent fault. The 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, the current measurement point is determined to be 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 when the third fault detection module detects that the effective voltage value is less than the voltage threshold, thus obtaining a third duration; and to detect whether the third duration is within a preset time window. When 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. The 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, detects whether three-phase voltage loss is detected again after a fourth time period. The fourth time period is the sum of the reclosing action time and the re-opening time of the first circuit breaker at the power supply-side measurement point. If three-phase voltage loss is detected after the fourth time period, the fault type is determined to be a permanent fault. 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 open when the fifth fault detection module determines that the fault type is a permanent fault. The second circuit breaker is the load-side circuit breaker of the fault section.

2. The distribution line short-circuit fault handling device utilizing 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 operating duration of the first circuit breaker.

3. The distribution line short-circuit fault handling device utilizing voltage and current time series information according to claim 1, characterized in that, The multiple measurement points correspond to multiple first durations, with the first durations increasing progressively from the measurement point near the end of the power source to the measurement point near the beginning of the power source.

4. The distribution line short-circuit fault handling device utilizing voltage and current time series information according to any one of claims 1 to 3, characterized in that, 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 power distribution line short-circuit fault handling device utilizing voltage and current time series information further includes: The sampling module is used to acquire 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 based on the measured current value and the measured voltage value.

5. The distribution line short-circuit fault handling device utilizing voltage and current time series information according to claim 4, characterized in that, Also includes: The 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. 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.

6. The distribution line short-circuit fault handling device utilizing voltage and current time series information according to any one of claims 1 to 3, characterized in that, The measurement point is located on a pillar outside the substation.

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