CN111781465A - Fault positioning system and method for ungrounded power grid - Google Patents
Fault positioning system and method for ungrounded power grid Download PDFInfo
- Publication number
- CN111781465A CN111781465A CN202010595934.XA CN202010595934A CN111781465A CN 111781465 A CN111781465 A CN 111781465A CN 202010595934 A CN202010595934 A CN 202010595934A CN 111781465 A CN111781465 A CN 111781465A
- Authority
- CN
- China
- Prior art keywords
- breaker
- circuit breaker
- voltage
- section
- switching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/088—Aspects of digital computing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Remote Monitoring And Control Of Power-Distribution Networks (AREA)
Abstract
The application provides a fault location system and method for an ungrounded power grid. The system that this application provided includes circuit and the distribution main website of awaiting measuring, and the section circuit breaker sets up voltage time type feeder automation function in advance, closes zero-voltage separating brake function and shutting combined floodgate function. In the application, the line selection device is used for acquiring zero sequence voltage, and if the zero sequence voltage is larger than a preset value, a tripping instruction is sent out. And the target outlet circuit breaker is used for executing a tripping action and executing a reclosing action after receiving the tripping instruction. And the section circuit breaker uploads the state of the section circuit breaker to a power distribution main station. The distribution main station is used for receiving the state of the sectional circuit breaker, and if the first sectional circuit breaker exists, the position of the first sectional circuit breaker and the position of the second sectional circuit breaker are determined; and determining the position of the ground fault according to the position of the first sectional breaker and the position of the second sectional breaker. The application combines the characteristics of components in the circuit to be tested to realize accurate positioning of the ground fault position.
Description
Technical Field
The present application relates to the field of electrical technologies, and in particular, to a fault location system and method for an ungrounded power grid.
Background
The general transmission process of the power transmission system is that a generator generates power, and the generated power is boosted or reduced by a transformer, then transmitted to a main feeder line and then dispersed to branch feeder lines by the main feeder line until transmitted to a user side. In order to ensure the reliability of power transmission, the reliability of the power transmission system can be improved by adopting a non-grounding mode for the neutral point of the transformer.
Fig. 1 is a schematic diagram of a circuit structure of a prior art ungrounded power grid. The circuit 1 to be tested is part of a power transmission system; the circuit 1 to be tested comprises a line selection device 11, a trunk feeder line and branch feeder lines (such as a branch feeder line 131 and a branch feeder line 132 shown in the figure); the line selection device 11 may be connected to one or more trunk feeders (e.g., a trunk feeder 121 and a trunk feeder 122 shown in the figure), and each trunk feeder may be connected to one or more branch feeders. Wherein the transformer 14 is connected to the bus bar 10, and the bus bar 10 is connected to the main feeder lines (such as the main feeder lines 121 and 122 shown in the figure). The line selection device 11 is arranged near the transformer 14. Taking the main feeder line 121 as an example, one end of the main feeder line 121 closer to the line selection device 11 is a head end of the main feeder line 121, and conversely, one end of the main feeder line 121 farther from the line selection device 11 is a tail end of the main feeder line. Every main feeder is provided with an export circuit breaker 15, and export circuit breaker 15 is close to the head end setting of main feeder. A plurality of section breakers (e.g., section breaker 161, section breaker 162, section breaker 163 shown in fig. 1) are disposed between the egress breakers and the ends of the main feeder. The branch feeder line is connected with the main feeder line 121 through a branch connection point (e.g., point a or point B shown in fig. 1); a branch connection point (point a or point B) is provided between the outlet circuit breaker 15 and the end of the main feeder 121 (excluding the outlet circuit breaker and the end of the main feeder); at least one branch breaker (shown as a branch breaker 171 or a branch breaker 172) is disposed on each branch feeder. Since a power transmission system of an ungrounded grid is large and complicated, a failure is likely to occur in the power transmission system. The grounding fault of the feeder line is one of main fault types in the power transmission system fault of the ungrounded power grid, and once the grounding fault occurs, the position of the grounding fault needs to be found as soon as possible to repair the grounding fault, so that normal power supply is recovered.
At present, if an earth fault occurs in a power transmission system of an ungrounded power grid, a trip instruction is usually sent by a line selection device to cut off a fault line, and then operation and maintenance personnel check the fault line by line in a region where the fault is likely to occur until the position of the earth fault is found. Because the structure of the power transmission system of the ungrounded power grid is complex and the number of branch lines is large, the method for positioning the ground fault mainly based on human judgment has low efficiency and even has the possibility that the position of the ground fault cannot be found.
Based on this, a fault positioning method for an ungrounded power grid is needed urgently at present, and is used for solving the problem that the efficiency is low when a grounding fault is positioned in the prior art.
Disclosure of Invention
The application provides a fault positioning system and method for an ungrounded power grid, which can be used for solving the problem that the efficiency is low when a grounding fault is positioned in the prior art.
In a first aspect, the application provides a fault location system for an ungrounded power grid, where the circuit to be tested includes a line selection device and a trunk feeder line connected to the line selection device; an outlet circuit breaker and a section circuit breaker are arranged on the main feeder line; the section breaker is positioned between the outlet breaker and the tail end of the main feeder line; the system is characterized by further comprising a power distribution main station, wherein the power distribution main station is connected with the segmented circuit breaker through a network; the sectionalizing circuit breaker is preset with a voltage time type feeder automation function, a zero-voltage switching-on and switching-off function and a locking switching-on function;
the line selection device is used for acquiring the zero sequence voltage of the bus to be detected, judging whether the zero sequence voltage is greater than a preset value or not, if the zero sequence voltage is greater than the preset value, determining a target main feeder line causing the zero sequence voltage to be greater than the preset value, and sending a trip instruction to a target outlet circuit breaker connected with the target main feeder line after a preset line selection trip time period;
the target outlet circuit breaker is used for executing a tripping action after receiving a tripping instruction sent by the line selection device; and power is obtained after the preset reclosing time period, and reclosing action is executed;
the target section circuit breaker is used for sending self states to the power distribution main station after corresponding actions are executed according to the voltage time type feeder automation function, the zero-voltage switching-on and zero-voltage switching-off function and the locking and switching-on function after the target outlet circuit breaker is switched on again; the target section breaker is a section short-circuiter corresponding to the target outlet breaker;
the power distribution main station is used for receiving the state of the target sectional breaker, judging whether a first sectional breaker in a zero-voltage switching-off state and a locking switching-on state exists or not, if the first sectional breaker exists, determining the position of the first sectional breaker, determining a second sectional breaker in a residual-voltage locking state, and determining the position of the second sectional breaker; and determining the position of the ground fault according to the position of the first subsection circuit breaker and the position of the second subsection circuit breaker.
With reference to the first aspect, in an implementation manner of the first aspect, the power distribution main station is further configured to:
and if the first section breaker does not exist, sending an instruction for starting other ground fault positioning modes.
With reference to the first aspect, in an implementation manner of the first aspect, the determining a location of a ground fault according to the location of the first section breaker and the location of the second section breaker is performed by:
and determining that the ground fault is located in a region between the first section breaker and the second section breaker according to the position of the first section breaker and the position of the second section breaker.
With reference to the first aspect, in an implementation manner of the first aspect, in the voltage time-based feeder automation function, a preset power-on delay switching-on time period is 7 seconds, a preset power-on holding time period is 5 seconds, and a preset voltage-loss delay switching-off time period is 0.5 seconds.
With reference to the first aspect, in an implementation manner of the first aspect, the preset line selection trip time period is greater than or equal to 5 seconds and less than or equal to 10 seconds.
With reference to the first aspect, in an implementation manner of the first aspect, the preset reclosing time period is greater than or equal to 1 second and less than or equal to 10 seconds.
In a second aspect, the present application provides a fault location method for an ungrounded power grid, the method being applied in a fault system for an ungrounded power grid; the system comprises a circuit to be tested, wherein the circuit to be tested comprises a line selection device and a trunk feeder line connected with the line selection device; an outlet circuit breaker and a section circuit breaker are arranged on the main feeder line; the section breaker is positioned between the outlet breaker and the tail end of the main feeder line; the system is characterized by further comprising a power distribution main station, wherein the power distribution main station is connected with the segmented circuit breaker through a network; the sectionalizing circuit breaker is preset with a voltage time type feeder automation function, a zero-voltage switching-on and switching-off function and a locking switching-on function; the method comprises the following steps:
the line selection device acquires zero sequence voltage of the bus;
the line selection device judges whether the zero sequence voltage is greater than a preset value;
if the line selection device determines that the zero sequence voltage is larger than the preset value, determining a target main feeder line causing the zero sequence voltage to be larger than the preset value, and sending a tripping instruction to a target outlet circuit breaker connected with the target main feeder line after a preset line selection tripping time period;
the target outlet circuit breaker executes a tripping action after receiving a tripping instruction sent by the line selection device;
the target outlet circuit breaker is electrified after a preset reclosing time period, and reclosing action is executed;
after the target outlet circuit breaker is reclosed, the target section circuit breaker sends the self state to the power distribution main station according to the voltage time type feeder automation function, the zero-voltage switching-on and switching-off function and the locking and switching-on function after executing corresponding actions; the target section breaker is a section short-circuiter corresponding to the target outlet breaker;
the power distribution main station is used for receiving the state of the target section breaker;
the power distribution master station judges whether a first sectional breaker in a zero-voltage switching-on state and a locking switching-off state exists or not;
if the distribution main station determines that the first sectional breaker exists, the position of the first sectional breaker is determined, a second sectional breaker in a residual voltage locking state is determined, and the position of the second sectional breaker is determined;
and the power distribution main station determines the position of the ground fault according to the position of the first sectional breaker and the position of the second sectional breaker.
With reference to the second aspect, in an implementable manner of the second aspect, the method further includes: and if the first subsection circuit breaker does not exist in the distribution main station, sending an instruction for starting other grounding fault positioning modes.
With reference to the second aspect, in an implementation manner of the second aspect, the power distribution main station determines a location of a ground fault according to the location of the first section breaker and the location of the second section breaker, and the method includes:
and the power distribution main station determines that the ground fault is positioned in an area between the first section breaker and the second section breaker according to the position of the first section breaker and the position of the second section breaker.
With reference to the second aspect, in an implementation manner of the second aspect, in the voltage time-based feeder automation function, a preset power-on delay switching-on time period is 7 seconds, a preset power-on holding time period is 5 seconds, and a preset voltage-loss delay switching-off time period is 0.5 seconds.
With reference to the second aspect, in an implementation manner of the second aspect, the preset line selection trip time period is greater than or equal to 5 seconds and less than or equal to 10 seconds.
With reference to the second aspect, in an implementation manner of the second aspect, the preset reclosing time period is greater than or equal to 1 second and less than or equal to 10 seconds.
This application sets up the reclosing function of export circuit breaker, combines the mechanical characteristic of segmentation circuit breaker, realizes earth fault's quick isolation to accurate location earth fault position. The change that this application need be measured the circuit and go on before realizing the locate function to ground fault is limited, utilized the original existing function of components and parts among the circuit that awaits measuring to the at utmost, and the scheme of this application is economical effective, can realize popularization on a large scale.
Drawings
Fig. 1 is a schematic circuit diagram of a prior art ungrounded power grid;
fig. 2 is a diagram of a fault location system for an ungrounded power grid according to an embodiment of the present application;
fig. 3 is a structural diagram of a fault location system in which a ground fault occurs according to an embodiment of the present application;
fig. 4 is a block diagram of another fault location system with a ground fault according to an embodiment of the present disclosure;
fig. 5 is a flowchart of a fault location method for an ungrounded power grid according to an embodiment of the present application.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
Fig. 2 is a diagram of a fault location system for an ungrounded power grid according to an embodiment of the present disclosure. As can be seen from fig. 2, the fault locating system includes a circuit 1 to be tested, and the circuit 1 to be tested includes a line selection device 11 and trunk feeders (e.g., trunk feeder 121 and trunk feeder 122 shown in fig. 2) connected to the line selection device 11; in the embodiment of the present application, a main feeder 121 is taken as an example for explanation, and an outlet breaker 15 and a section breaker 121 are arranged on the main feeder 121; the section breakers are located between the outlet breakers 15 and the ends of the main feeder 121; the fault positioning system further comprises a power distribution main station 2, and the power distribution main station 2 is connected with the segmented circuit breaker through a network.
It should be noted that other trunk feed lines, such as the trunk feed line 122, have a similar structure to the trunk feed line 121, and are not described herein again.
As can also be seen from fig. 2, a plurality of section breakers, for example, the section breaker 161, the section breaker 162 and the section breaker 163 … … shown in fig. 2, are distributed on the main feeder 121 from the outlet breaker 15 to the end of the main feeder 121 to divide the main feeder 121 into a plurality of parts.
One or more branch feeders (e.g., branch feeder 131 and branch feeder 132 in fig. 2) are disposed between the outlet circuit breaker 15 and the end of the main feeder 121, and one or more branch circuit breakers are disposed on each branch feeder.
The following describes in detail the workflow of the fault location system in the embodiment of the present application.
The line selection device 11 is used for acquiring zero sequence voltage at a bus of the circuit 1 to be tested, judging whether the zero sequence voltage is greater than zero, if the zero sequence voltage is greater than zero, determining a target main feeder line causing the zero sequence voltage to be greater than zero, and sending a trip instruction to a target outlet circuit breaker connected with the target main feeder line after a preset line selection trip time period. If the target outlet breaker does not exist, the line selection device 11 continues to select the zero sequence voltage at the bus of the circuit 1 to be tested in the next period.
Specifically, if no ground fault occurs in the circuit 1 to be tested, the zero sequence voltage values acquired by the line selection device 11 are all zero, and if a zero sequence voltage larger than zero occurs (the voltage value range of a general zero sequence voltage value is greater than or equal to 20V and less than or equal to 25V), which indicates that a ground fault occurs at this time, the line selection device 11 starts an algorithm, for example, selects a target trunk feeder line having a zero sequence voltage larger than a preset value by using a transient method (a transient zero-mode current group comparison method and a transient direction method), determines a target outlet breaker according to the target trunk feeder line, and sends a trip instruction to the target outlet breaker after a preset line selection trip time period.
In the embodiment of the application, the preset line selection tripping time period is set to be greater than or equal to 5 seconds and less than or equal to 10 seconds.
The target outlet circuit breaker is used for executing tripping action after receiving a tripping instruction sent by the line selection device 11; and obtaining power after the preset reclosing time period, and executing reclosing action.
Specifically, after receiving a trip command from the line selection device 11, the target outlet circuit breaker performs a trip operation. Correspondingly, the main feeder 121 corresponding to the target outlet circuit breaker loses power after the target outlet circuit breaker performs a trip operation.
The outlet circuit breaker 15 in the embodiment of the present application may set a preset reclosing time period in advance, where the preset reclosing time period is generally greater than or equal to 1 second and less than or equal to 10 seconds. After a preset reclosing time period, the target outlet circuit breaker can automatically execute reclosing action.
After the target outlet circuit breaker automatically performs the reclosing action, the main feeder 121 corresponding to the target outlet circuit breaker is powered again.
And the target section circuit breaker is used for sending self states to the power distribution main station after corresponding actions are executed according to the voltage time type feeder automation function, the zero-voltage switching-on and zero-voltage switching-off function and the locking and switching-on function after the target outlet circuit breaker is switched on again.
Specifically, the target section breaker is a section short-circuiting device corresponding to the target outlet breaker. Taking fig. 2 as an example, if the outlet breaker is a 15-bit target outlet breaker, any one of the section breaker 161, the section breaker 162, and the section breaker 163 shown in fig. 2 is a target section breaker.
In the embodiment of the application, the sectional breaker is preset with a voltage time type feeder automation function, a zero-voltage switching-off function and a locking switching-on function.
In the voltage time type feeder automation function, a preset power-on delay switching-on time period is 7 seconds, namely, the segmented circuit breaker delays for 7 seconds after power is on and then performs switching-on action; the preset power-on maintaining time period is 5 seconds, namely the segmented circuit breaker automatically maintains the power-on state for 5 seconds after power-on; the voltage-loss delay switching-off time period is preset to be 0.5 second, namely, the switching-off action is carried out after 0.5 second passes through the sectional breaker in a voltage-loss state. The switching-on and zero-voltage switching-off function of the sectional breaker enables the sectional breaker to automatically perform switching-off action if the sectional breaker is in a zero-voltage state after switching-on. The sectionalizer can enable nearby feeder lines to be in an isolated state if the sectionalizer performs a closing and locking function.
After the target outlet circuit breaker loses power, the section circuit breakers distributed on the main feeder line 121 corresponding to the target outlet circuit breaker also lose power, and a tripping action is executed after a preset voltage loss delay brake-separating time period.
After the target outlet circuit breaker is powered again, because the section circuit breaker presets a voltage time type feeder automation function, the section circuit breaker executes a switching-on action after passing through a preset power delay switching-on time period in sequence from the head end to the tail end of the main feeder 121.
Specifically, as shown in fig. 2, the section breakers are sequentially closed in the order of the section breaker 161, the section breaker 162, and the section breaker 163 … …. And when one section breaker executes the closing action, all the section breakers executing the closing action detect the zero sequence voltage. If the zero sequence voltage obtained by the detection of the section breaker which executes the closing action newly is zero, the next section breaker in sequence from the head end to the tail end along the main feeder 121 continues to execute the closing action. And if the section breaker which executes the closing action newly detects the zero-sequence voltage which is larger than zero. The section breaker which executes the closing action newly executes the opening action to zero voltage and the closing action to lock, keeps the opening state to zero voltage and the closing state to lock, and uploads the opening state to zero voltage and the closing state to the distribution main station 2. And the next segmented circuit breaker in sequence from the head end to the tail end along the main feeder 121 utilizes residual voltage to execute residual voltage locking action within a preset electric delay closing time period, keeps a residual voltage locking state and uploads the self residual voltage locking state to the power distribution main station 2.
For example, as shown in fig. 2, after the section breaker 161 performs the closing operation, only the section breaker 161 is currently closed, so that the section breaker 161 detects the zero sequence voltage. If the zero sequence voltage is zero, the section breaker 162 continues to perform a closing action. If the zero sequence voltage is greater than zero, the sectionalizing circuit breaker 161 performs a zero-voltage switching-on action and a closing-off action, maintains a zero-voltage switching-on state and a closing-off state, and uploads the self zero-voltage switching-on state and the closing-off state to the distribution main station 2. The next sectionalizer 162 of the sectionalizer 161 performs the residual voltage blocking action by using the residual voltage within the preset electric delay closing time period, maintains the residual voltage blocking state, and uploads the residual voltage blocking state of itself to the power distribution main station 2.
It should be noted that, the section breaker 161 performs a zero-voltage opening operation and a closing operation, and the section breaker 162 performs a residual voltage closing operation within a preset electric delay closing time period, which is equivalent to isolating a ground fault outside the circuit 1 to be tested, and the voltage transmitted at other places in the power grid is not affected by the ground fault again, so that the possibility of false operation of the section breaker or other elements near the ground fault position is avoided, and meanwhile, the accuracy of information acquisition by the power distribution main station 2 is also ensured.
In the embodiment of the present application, the value of the zero sequence voltage of the sectionalizer, which is preset by the sectionalizer and can be detected, is set to be greater than or equal to 18V and less than or equal to 20V, and is numerically less than the value of the zero sequence voltage of the outlet circuit breaker 15, which can be detected by the line selection device 11. This arrangement is to prevent the line selection device 11 from issuing a trip command again to disconnect the entire feeder line 121 before the sectionalizing circuit breaker is operated.
The power distribution main station 2 is used for receiving the state of the target sectional breaker, judging whether a first sectional breaker in a zero-voltage switching-off state and a locking switching-on state exists or not, if the first sectional breaker exists, determining the position of the first sectional breaker, determining a second sectional breaker in a residual voltage locking state, and determining the position of the second sectional breaker; and determining the position of the ground fault according to the position of the first sectional breaker and the position of the second sectional breaker.
Specifically, the distribution main station 2 may determine that the ground fault is located in the region between the first and second segmented circuit breakers according to the position of the first segmented circuit breaker and the position of the second segmented circuit breaker.
In order to more clearly understand the area between the first and second segmented circuit breakers, the following is further illustrated by two examples.
Example 1
As shown in fig. 3, for the structure diagram of a fault location system with a ground fault provided in this embodiment of the present application, a fault 31 occurs in a circuit 1 to be tested, in this case, after the line selection device 11 and the target outlet circuit breaker have performed their respective functions, the distribution master station 2 receives a state of a section breaker on the main feeder 121 corresponding to the target outlet circuit breaker, determines that there is a first section breaker (i.e., the section breaker 162 in fig. 3) in a closing state and a closing state, determines that a position of the first section breaker is the section breaker 162 in fig. 3, determines that a position of the first section breaker is a second section breaker (i.e., the section breaker 163 in fig. 3) in a residual voltage closing state, and determines that a position of the second section breaker is the section breaker 163 in fig. 2. The distribution main station 2 determines, based on the position of the first section breaker and the position of the second section breaker, that the position of the ground fault is on the main feeder 121 between the section breaker 162 and the section breaker 163 or on the branch feeder 132 connected to the main feeder 121 between the section breaker 162 and the section breaker 163, and further examination can determine that the ground fault occurs on the main feeder 121 between the section breaker 162 and the section breaker 163.
Example two
As shown in fig. 4, for another structure diagram of a fault location system with a ground fault, provided in this embodiment of the present application, a fault 32 occurs in a circuit 1 to be tested, in this case, after a line selection device 11 and a target outlet circuit breaker perform their respective functions, a distribution main station 2 receives a state of a section breaker on a main feeder 121 corresponding to the target outlet circuit breaker, determines that there is a first section breaker (i.e., the section breaker 161 in fig. 4) in a closing-to-zero-voltage opening state and a closing-off state, determines that a position of the first section breaker is the section breaker 161 in fig. 4, determines that a position of the first section breaker is a second section breaker (i.e., the section breaker 162 in fig. 4) in a residual-voltage closing state, and determines that a position of the second section breaker is the section breaker 2 in fig. 4. The distribution main station 2 determines, based on the position of the first section breaker and the position of the second section breaker, that the position of the ground fault is on the main feeder 121 between the section breaker 161 and the section breaker 162 or on the branch feeder 131 connected to the main feeder 121 between the section breaker 161 and the section breaker 162, and further examination may determine that the ground fault occurs on the branch feeder 131 connected to the main feeder 121 between the section breaker 161 and the section breaker 162.
The above example is where the ground fault occurs from the first section breaker 161 from the head end of the main feeder 121 to the end of the main feeder 121.
It should be added that the power distribution main station 2 is also configured to issue an instruction to start another ground fault location method if the first sectionalizer is not present.
It is further noted that if there is no first section breaker, this is probably because the fault occurred between the egress breaker 15 and the first section breaker 161 from the head of the main feeder 121. In this case, the sectionalizer has no way to perform the pre-set on-zero voltage opening and closing actions, and thus there is no first sectionalizer. The instruction that starts other earth fault locate modes that distribution main website 2 sent this moment can be considered and is reminding the staff to investigate between the first section circuit breaker 161 that export circuit breaker 15 and main feeder 121 head end were started, seeks the earth fault position.
This application sets up exit circuit breaker 15's reclosing function, combines the mechanical characteristic of segmentation circuit breaker, realizes earth fault's quick isolation to accurate location earth fault position. The change that this application need be measured the circuit and go on before realizing the locate function to ground fault is limited, utilized the original existing function of components and parts among the circuit that awaits measuring to the at utmost, and the scheme of this application is economical effective, can realize popularization on a large scale.
The following are embodiments of the method of the present application that may be used in embodiments of the system of the present application. For details which are not disclosed in the method embodiments of the present application, reference is made to the system embodiments of the present application.
Fig. 5 is a flowchart illustrating a fault location method for an ungrounded power grid according to an embodiment of the present application. The method is applied in a fault location system for an ungrounded power grid. The method is applied to a fault system for an ungrounded power grid; the system comprises a circuit to be tested, wherein the circuit to be tested comprises a line selection device and a trunk feeder line connected with the line selection device; an outlet circuit breaker and a section circuit breaker are arranged on the main feeder line; the section breaker is positioned between the outlet breaker and the tail end of the main feeder line; the fault positioning system of the ungrounded power grid further comprises a power distribution main station, wherein the power distribution main station is connected with the segmented circuit breaker through a network; the sectionalizing circuit breaker is preset with a voltage time type feeder automation function, a zero-voltage switching-on and switching-off function and a locking switching-on function. The specific process of the method implemented and provided by the application is as follows:
Step 502, the line selection device judges whether the zero sequence voltage is greater than a preset value, if the zero sequence voltage is greater than the preset value, step 503 is executed, otherwise, step 501 is executed.
And step 504, after the target outlet circuit breaker receives a tripping command sent by the line selection device, the tripping action is executed.
And 505, the target outlet circuit breaker is electrified after a preset reclosing time period, and reclosing action is executed.
In step 507, the target sectionalizer sends its own status to the distribution main station.
In step 508, the distribution master receives the status of the target section breaker.
In step 509, the distribution master station determines whether there is a first sectionalized breaker in a zero-voltage opening state and a closed-closing state, if there is a first sectionalized breaker, step 510 is executed, otherwise, step 512 is executed.
Step 510, the distribution master station determines the position of the first sectionalized breaker, determines the second sectionalized breaker in the residual voltage blocking state, and determines the position of the second sectionalized breaker.
And 511, the power distribution main station determines the position of the ground fault according to the position of the first sectional breaker and the position of the second sectional breaker.
And step 512, the power distribution main station sends out an instruction for starting other ground fault positioning modes.
The target section breaker is a section breaker corresponding to the target outlet breaker.
Optionally, the power distribution main station determines the position of the ground fault according to the position of the first section breaker and the position of the second section breaker, and the method includes the following steps:
and the power distribution main station determines that the ground fault is positioned in the area between the first section breaker and the second section breaker according to the position of the first section breaker and the position of the second section breaker.
Optionally, in the voltage time type feeder automation function, a preset power-on delay switching-on time period is 7 seconds, a preset power-on holding time period is 5 seconds, and a preset voltage-loss delay switching-off time period is 0.5 seconds.
Optionally, the preset line selection trip time period is greater than or equal to 5 seconds and less than or equal to 10 seconds.
Optionally, the preset reclosing time period is greater than or equal to 1 second and less than or equal to 10 seconds.
This application sets up the reclosing function of export circuit breaker, combines the mechanical characteristic of segmentation circuit breaker, realizes earth fault's quick isolation to accurate location earth fault position. The change that this application need be measured the circuit and go on before realizing the locate function to ground fault is limited, utilized the original existing function of components and parts among the circuit that awaits measuring to the at utmost, and the scheme of this application is economical effective, can realize popularization on a large scale.
The invention is operational with numerous general purpose or special purpose computing system environments or configurations. For example: personal computers, server computers, hand-held or portable devices, tablet-type devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.
The invention may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.
Claims (10)
1. The fault positioning system for the ungrounded power grid comprises a circuit to be tested, wherein the circuit to be tested comprises a line selection device and a main feeder line connected with the line selection device; an outlet circuit breaker and a section circuit breaker are arranged on the main feeder line; the section breaker is positioned between the outlet breaker and the tail end of the main feeder line; the system is characterized by further comprising a power distribution main station, wherein the power distribution main station is connected with the segmented circuit breaker through a network; the sectionalizing circuit breaker is preset with a voltage time type feeder automation function, a zero-voltage switching-on and switching-off function and a locking switching-on function;
the line selection device is used for acquiring zero sequence voltage of the bus, judging whether the zero sequence voltage is greater than a preset value or not, if the zero sequence voltage is greater than the preset value, determining a target main feeder line causing the zero sequence voltage to be greater than the preset value, and sending a trip instruction to a target outlet circuit breaker connected with the target main feeder line after a preset line selection trip time period;
the target outlet circuit breaker is used for executing a tripping action after receiving a tripping instruction sent by the line selection device; and power is obtained after the preset reclosing time period, and reclosing action is executed;
the target section circuit breaker is used for sending self states to the power distribution main station after corresponding actions are executed according to the voltage time type feeder automation function, the zero-voltage switching-on and zero-voltage switching-off function and the locking and switching-on function after the target outlet circuit breaker is switched on again; the target section breaker is a section short-circuiter corresponding to the target outlet breaker;
the power distribution main station is used for receiving the state of the target sectional breaker, judging whether a first sectional breaker in a zero-voltage switching-off state and a locking switching-on state exists or not, if the first sectional breaker exists, determining the position of the first sectional breaker, determining a second sectional breaker in a residual-voltage locking state, and determining the position of the second sectional breaker; and determining the position of the ground fault according to the position of the first subsection circuit breaker and the position of the second subsection circuit breaker.
2. The fault locating system of claim 1, wherein the power distribution master station is further configured to:
and if the first section breaker does not exist, sending an instruction for starting other ground fault positioning modes.
3. The fault location system of claim 1, wherein the determining the location of the ground fault from the location of the first segmented circuit breaker and the location of the second segmented circuit breaker is achieved by:
and determining that the ground fault is located in a region between the first section breaker and the second section breaker according to the position of the first section breaker and the position of the second section breaker.
4. The fault locating system according to claim 1, wherein in the voltage time type feeder automation function, a preset power-on delay switching-on time period is 7 seconds, a preset power-on holding time period is 5 seconds, and a preset voltage-loss delay switching-off time period is 0.5 seconds.
5. The fault locating system of claim 1, wherein the preset line selection trip time period is greater than or equal to 5 seconds and less than or equal to 10 seconds.
6. The fault locating system of claim 1, wherein the preset reclosing time period is greater than or equal to 1 second and less than or equal to 10 seconds.
7. Fault localization method for an ungrounded grid, characterized in that the method is applied in a fault system for an ungrounded grid; the system comprises a circuit to be tested, wherein the circuit to be tested comprises a line selection device and a trunk feeder line connected with the line selection device; an outlet circuit breaker and a section circuit breaker are arranged on the main feeder line; the section breaker is positioned between the outlet breaker and the tail end of the main feeder line; the system is characterized by further comprising a power distribution main station, wherein the power distribution main station is connected with the segmented circuit breaker through a network; the sectionalizing circuit breaker is preset with a voltage time type feeder automation function, a zero-voltage switching-on and switching-off function and a locking switching-on function; the method comprises the following steps:
the line selection device acquires zero sequence voltage of the bus;
the line selection device judges whether the zero sequence voltage is greater than a preset value;
if the line selection device determines that the zero sequence voltage is larger than the preset value, determining a target main feeder line causing the zero sequence voltage to be larger than the preset value, and sending a tripping instruction to a target outlet circuit breaker connected with the target main feeder line after a preset line selection tripping time period;
the target outlet circuit breaker executes a tripping action after receiving a tripping instruction sent by the line selection device;
the target outlet circuit breaker is electrified after a preset reclosing time period, and reclosing action is executed;
after the target outlet circuit breaker is reclosed, the target section circuit breaker sends the self state to the power distribution main station according to the voltage time type feeder automation function, the zero-voltage switching-on and switching-off function and the locking and switching-on function after executing corresponding actions; the target section breaker is a section short-circuiter corresponding to the target outlet breaker;
the power distribution main station is used for receiving the state of the target section breaker;
the power distribution master station judges whether a first sectional breaker in a zero-voltage switching-on state and a locking switching-off state exists or not;
if the distribution main station determines that the first sectional breaker exists, the position of the first sectional breaker is determined, a second sectional breaker in a residual voltage locking state is determined, and the position of the second sectional breaker is determined;
and the power distribution main station determines the position of the ground fault according to the position of the first sectional breaker and the position of the second sectional breaker.
8. The method of fault location according to claim 7, further comprising: and if the first subsection circuit breaker does not exist in the distribution main station, sending an instruction for starting other grounding fault positioning modes.
9. The method of claim 7, wherein the distribution main station determines a location of a ground fault based on the location of the first segmented circuit breaker and the location of the second segmented circuit breaker by:
and the power distribution main station determines that the ground fault is positioned in an area between the first section breaker and the second section breaker according to the position of the first section breaker and the position of the second section breaker.
10. The fault location method according to claim 7, wherein a preset power-on delay switching-on time period is 7 seconds, a preset power-on holding time period is 5 seconds, and a preset voltage-loss delay switching-off time period is 0.5 seconds in the voltage time type feeder automation function.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010595934.XA CN111781465A (en) | 2020-06-28 | 2020-06-28 | Fault positioning system and method for ungrounded power grid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010595934.XA CN111781465A (en) | 2020-06-28 | 2020-06-28 | Fault positioning system and method for ungrounded power grid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111781465A true CN111781465A (en) | 2020-10-16 |
Family
ID=72761322
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010595934.XA Pending CN111781465A (en) | 2020-06-28 | 2020-06-28 | Fault positioning system and method for ungrounded power grid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111781465A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112540322A (en) * | 2020-12-29 | 2021-03-23 | 广东电网有限责任公司电力科学研究院 | Line selection method, device and equipment for single-phase earth fault line of feeder line of transformer substation |
| CN113866563A (en) * | 2021-09-30 | 2021-12-31 | 广东电网有限责任公司东莞供电局 | Voltage current type feeder automation test system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106329500A (en) * | 2016-10-27 | 2017-01-11 | 珠海许继电气有限公司 | Method for treatment on distribution wire fault |
| CN106786425A (en) * | 2017-01-16 | 2017-05-31 | 中国电力科学研究院 | A kind of coincidence formula failure separation method and system on the spot |
| CN108448545A (en) * | 2018-04-12 | 2018-08-24 | 国网湖北省电力有限公司电力科学研究院 | A kind of formula feeder automation fault handling method of coincidence on the spot based on breaker |
| CN109038475A (en) * | 2018-08-31 | 2018-12-18 | 广东电网有限责任公司 | A kind of distribution network overhead line self-recovery method based on voltage time logic |
| CN109061378A (en) * | 2018-06-09 | 2018-12-21 | 广西电网有限责任公司电力科学研究院 | Small current neutral grounding system ground fault checks method |
-
2020
- 2020-06-28 CN CN202010595934.XA patent/CN111781465A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106329500A (en) * | 2016-10-27 | 2017-01-11 | 珠海许继电气有限公司 | Method for treatment on distribution wire fault |
| CN106786425A (en) * | 2017-01-16 | 2017-05-31 | 中国电力科学研究院 | A kind of coincidence formula failure separation method and system on the spot |
| CN108448545A (en) * | 2018-04-12 | 2018-08-24 | 国网湖北省电力有限公司电力科学研究院 | A kind of formula feeder automation fault handling method of coincidence on the spot based on breaker |
| CN109061378A (en) * | 2018-06-09 | 2018-12-21 | 广西电网有限责任公司电力科学研究院 | Small current neutral grounding system ground fault checks method |
| CN109038475A (en) * | 2018-08-31 | 2018-12-18 | 广东电网有限责任公司 | A kind of distribution network overhead line self-recovery method based on voltage time logic |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112540322A (en) * | 2020-12-29 | 2021-03-23 | 广东电网有限责任公司电力科学研究院 | Line selection method, device and equipment for single-phase earth fault line of feeder line of transformer substation |
| CN113866563A (en) * | 2021-09-30 | 2021-12-31 | 广东电网有限责任公司东莞供电局 | Voltage current type feeder automation test system |
| CN113866563B (en) * | 2021-09-30 | 2024-02-13 | 广东电网有限责任公司东莞供电局 | Voltage-current feeder automation test system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2021203476B2 (en) | Nested microgrid control system | |
| EP3570400B1 (en) | Method and apparatus for use in earth-fault protection | |
| EP3266086B1 (en) | Method for protection in a mixed power transmission line | |
| US11128127B2 (en) | FLISR without communication | |
| EP1416603B1 (en) | Protection of an electric power transmission network | |
| US10756571B2 (en) | System and method for stabilizing power system | |
| CN109564257A (en) | The fault detection and protection carried out during stable state using traveling wave | |
| US11205892B2 (en) | Method for locating phase faults in a microgrid | |
| EP3605436B1 (en) | Method for locating phase faults in a microgrid and controller | |
| US11143715B2 (en) | Broken conductor detection in a multiple-phase electric power delivery system | |
| CN108957243A (en) | A kind of method for locating single-phase ground fault and system applied to power distribution network | |
| JP5051225B2 (en) | Power distribution system, accident search / division method | |
| CN111781465A (en) | Fault positioning system and method for ungrounded power grid | |
| CN109061378A (en) | Small current neutral grounding system ground fault checks method | |
| US11309699B2 (en) | Control system for and method of fault location, isolation and supply restoration | |
| CN111781466A (en) | Fault positioning system and method for arc suppression coil grounding power grid | |
| CN117096836A (en) | Override trip protection system, method and storage medium for same-pole multi-circuit line | |
| CN111781464A (en) | Fault positioning system and method for arc suppression coil and small-resistance grounding power grid | |
| CN111766472A (en) | Fault positioning system and method for low-resistance grounding power grid | |
| US10962608B1 (en) | High-impedance fault detection using wireless current transformers | |
| Allen | Effects of wide-area control on the protection and operation of distribution networks | |
| Teo | A computer aided system to automate the restoration of electrical power supply | |
| US11728638B2 (en) | Normally open tie pulse testing | |
| Li et al. | A cost-effective approach for feeder fault detection and location of radial distribution networks | |
| US11646603B2 (en) | Single phase fault isolation and restoration with loop avoidance for multiple tie-in devices |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201016 |