CN115296274A - Fault positioning and bus protection method and system - Google Patents
Fault positioning and bus protection method and system Download PDFInfo
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- CN115296274A CN115296274A CN202210958775.4A CN202210958775A CN115296274A CN 115296274 A CN115296274 A CN 115296274A CN 202210958775 A CN202210958775 A CN 202210958775A CN 115296274 A CN115296274 A CN 115296274A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/22—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices
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- 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
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- 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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
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- 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
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Abstract
The invention discloses a fault positioning and bus protection method and system. The fault positioning and bus protection method comprises the following steps: collecting simulation information and switch information of a fault positioning and bus protection system; determining the area where the fault point is located according to the simulation information; and controlling the switch in the area where the fault point is located to be switched off according to the area where the fault point is located and the switch information. The embodiment of the invention judges the fault location and the fault area of the bus protection system by acquiring the simulation information of the secondary side of the first main transformer and the secondary side of the second main transformer; and the switch of the fault location and bus protection system fault area is disconnected by acquiring the switch information of the secondary side of the first main transformer and the secondary side of the second main transformer, so that the fault location and bus protection system fault area is accurately judged and isolated.
Description
Technical Field
The invention relates to the technical field of electric power, in particular to a fault positioning and bus protection method and system.
Background
The low voltage side of the main transformer of the transformer station is generally connected in an angle mode, and therefore the side is called a triangular side. Since the angle type connection has no neutral point, grounding is generally achieved by artificially forming a grounding point through grounding.
The most common grounding method among artificially formed grounding points is grounding of the bus bars via a grounding small resistance. Because the triangle side bus is not provided with bus protection, when a fault occurs in the system after the bus is grounded through a grounding small resistor, the fault area cannot be accurately positioned and isolated.
Disclosure of Invention
The invention provides a fault positioning and bus protection method and system, which can accurately position and isolate a fault area.
According to an aspect of the present invention, a fault location and bus protection method is provided, which is applied to a fault location and bus protection system, where the fault location and bus protection system at least includes a main transformer and a bus, the main transformer includes a first main transformer and a second main transformer, and the bus includes a first bus and a second bus; the first bus is connected with the secondary side of the first main transformer, and the second bus is connected with the secondary side of the second main transformer; a communication switch is arranged between the first bus and the second bus; each bus is connected with a plurality of feeders and a grounding transformer, and the grounding transformer is grounded through a small resistor; a switch is arranged between each bus and the main transformer, the grounding transformer and the feeder;
the method comprises the following steps:
collecting simulation information and switch information of a fault positioning and bus protection system;
determining the area where the fault point is located according to the simulation information;
and controlling the switch in the area where the fault point is located to be switched off according to the area where the fault point is located and the switch information.
Optionally, the collecting analog information and switch information of the fault location and bus protection system includes:
acquiring simulation information of a fault positioning and bus protection system through a zero sequence current transformer; the secondary side of the main transformer of the fault positioning and bus protection system is connected in a triangular mode; the analog information comprises three-phase current and zero-sequence current of the secondary side of the main transformer, three-phase current and zero-sequence current of each feeder line, three-phase current of the primary side of the grounding transformer, zero-sequence current of the small resistor of the secondary side of the grounding transformer and interval capacitive current;
collecting the switch information of the fault positioning and bus protection system; the switching information includes a switching position of the secondary side of the main transformer, a position of the interconnection switch, a switching position of each feeder line, and a switching position of the grounding transformer.
Optionally, the determining, according to the simulation information, an area where the fault point is located includes:
determining the fault of the zero sequence current transformer of the grounding transformer according to the three-phase current of the primary side of the grounding transformer and the zero sequence current of the secondary side of the grounding transformer;
determining a bus area fault according to a vector sum of a fault location and a total zero sequence current of a bus protection system and a zero sequence vector sum threshold value; the bus region faults comprise bus short-circuit faults, dead zone short-circuit faults close to interconnection switches, short-circuit faults of feeder lines close to the bus side and short-circuit faults of switches on the secondary side of the main transformer close to the bus side;
determining that a high-resistance ground fault occurs in a region from a secondary side coil of the main transformer to a switch of a secondary side of the main transformer according to the magnitude and the direction of the zero-sequence current of the secondary side of the main transformer and the zero-sequence current of a small resistor of the secondary side of the ground transformer;
determining that the feeder line has a single-phase ground fault according to the magnitude and the direction of the zero-sequence current of the feeder line and the zero-sequence current of the small resistor on the secondary side of the grounding transformer; or determining that at least two feeders are outside the station external network and generating single-phase earth fault.
Optionally, the determining the fault of the zero sequence current transformer of the grounding transformer according to the three-phase current at the primary side of the grounding transformer and the zero sequence current at the secondary side of the grounding transformer includes:
calculating the sum of the three-phase currents on the primary side of the grounding transformer according to the three-phase currents on the primary side of the grounding transformer;
and comparing the sum of the three-phase currents on the primary side of the grounding transformer with the zero-sequence current on the secondary side of the grounding transformer, and judging the fault states of the current transformer on the primary side of the grounding transformer, the zero-sequence current transformer on the secondary side of the grounding transformer and the inside of the grounding transformer according to the comparison result.
Optionally, the comparing the sum of the three-phase currents on the primary side of the grounding transformer with the zero-sequence current on the secondary side of the grounding transformer, and determining the fault states of the current transformer on the primary side of the grounding transformer, the zero-sequence current transformer on the secondary side of the grounding transformer, and the inside of the grounding transformer according to the comparison result includes:
i when jd -I j0 I1>I z1 Then, judging the zero sequence current transformer on the secondary side of the grounding transformer and the internal fault of the grounding transformer; wherein, the first and the second end of the pipe are connected with each other,I z1 as a setting value, I jd Is the sum of the three-phase currents on the primary side of the grounding transformer, I j0 Is the zero sequence current of the secondary side of the grounding transformer.
Optionally, the determining the bus area fault according to the vector sum of the total zero-sequence current of the fault location and bus protection system and the zero-sequence vector sum threshold value includes:
comparing the total zero sequence current of the fault positioning and bus protection system with the zero sequence vector and a threshold value to generate a comparison result;
and determining the fault of the bus area according to the comparison result.
Optionally, the determining a high-resistance ground fault in a region between a secondary side coil of the main transformer and a switch of the secondary side of the main transformer according to the magnitude and the direction of the zero-sequence current of the secondary side of the main transformer and the zero-sequence current of the small resistor of the secondary side of the grounding transformer includes:
comparing the zero sequence current of the secondary side of the main transformer with the zero sequence current of the small resistor of the secondary side of the grounding transformer;
and when the direction of the zero sequence current of the secondary side of the main transformer is opposite to that of the zero sequence current of the small resistor of the secondary side of the grounding transformer, and the vector sum of the direction of the zero sequence current of the secondary side of the main transformer and that of the zero sequence current of the small resistor of the secondary side of the grounding transformer is zero, judging the high-resistance grounding fault in the area from the coil of the secondary side of the main transformer to the switch of the secondary side of the main transformer.
Optionally, the feeder line is determined to have a single-phase ground fault according to the magnitude and direction of the zero-sequence current of the feeder line and the zero-sequence current of the small resistor on the secondary side of the grounding transformer; or, determining that at least two feeders form a ring network and a single-phase earth fault occurs outside the station, including:
comparing the zero sequence current of the feeder line with the zero sequence current of a small resistor on the secondary side of the grounding transformer;
when the zero sequence current of the feeder line and the zero sequence current of the small resistance on the secondary side of the grounding transformerThe directions are opposite, the vector sum of the zero sequence current of the feeder line and the zero sequence current of the small resistor on the secondary side of the grounding transformer is zero, and the maximum value of the zero sequence current of the feeder line is more than X%. I j0 When the feeder line is in single-phase ground fault, judging that the feeder line has single-phase ground fault, or at least two feeder lines form a ring network and have single-phase ground fault outside the station; wherein, X% is percentage, and when the fault location and bus protection system has no external ring network in the station, X% =80% is set; when two feeders on the same section of bus are in an off-station ring network, setting X% =40%; when three feeders on the same section of bus are in an off-station ring network, X% =30% is set.
Optionally, the controlling, according to the area where the fault point is located and the switch information, the switch in the area where the fault point is located to be turned off includes:
when the zero sequence current transformer of the grounding transformer fails, controlling a switch at the primary side of the grounding transformer to be switched off, and locking the protection of the grounding transformer;
when the bus area has a fault, controlling a switch of the bus area to be switched off after a level difference, and locking a standby automatic switching-in device;
when a high-resistance ground fault occurs in a region from a secondary side coil of the main transformer to a switch on the secondary side of the main transformer, controlling the switch on the secondary side of the main transformer to be switched off after a level difference;
when the feeder line has a single-phase earth fault, or at least two feeder lines are in an out-of-station network and have a single-phase earth fault, controlling the switch of the faulty feeder line to be switched off after a level difference, and locking the reclosure of the feeder line.
According to another aspect of the present invention, there is provided a fault location and bus protection system, comprising:
a main transformer and a bus bar,
the main transformers comprise a first main transformer and a second main transformer, and the bus comprises a first bus and a second bus; the first bus is connected with the secondary side of the first main transformer, and the second bus is connected with the secondary side of the second main transformer; a communication switch is arranged between the first bus and the second bus; each bus is connected with a plurality of feeders and a grounding transformer, and the grounding transformer is grounded through a small resistor; a switch is arranged between each bus and the main transformer, the grounding transformer and the feeder;
the zero sequence current transformer is used for acquiring simulation information and switching information of a fault positioning and bus protection system;
the fault positioning module is used for determining the area where the fault point is located according to the simulation information;
and the control module is used for controlling the switch in the area where the fault point is located to be switched off according to the area where the fault point is located and the switch information.
According to the technical scheme of the embodiment of the invention, the fault location and the fault area of the bus protection system are judged by acquiring the simulation information of the secondary side of the first main transformer and the secondary side of the second main transformer; and the switch of the fault location and bus protection system fault area is disconnected by collecting the switch information of the secondary side of the first main transformer and the secondary side of the second main transformer. Therefore, the embodiment of the invention can realize the accurate judgment and the accurate isolation of the fault location and the fault area of the bus protection system.
It should be understood that the statements in this section are not intended to identify key or critical features of the embodiments of the present invention, nor are they intended to limit the scope of the invention. Other features of the present invention will become apparent from the following description.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic flowchart of a fault location and bus protection method according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a fault location and bus protection system according to an embodiment of the present invention;
fig. 3 is a schematic flowchart of another fault location and bus protection method according to an embodiment of the present invention;
fig. 4 is a schematic flowchart of another fault location and bus protection method according to an embodiment of the present invention;
fig. 5 is a schematic flowchart of another fault location and bus protection method according to an embodiment of the present invention.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Fig. 1 is a schematic flowchart of a fault location and bus protection method according to an embodiment of the present invention. Fig. 2 is a schematic structural diagram of a fault location and bus protection system according to an embodiment of the present invention. Referring to fig. 2, the fault location and bus protection system at least comprises a main transformer and a bus, wherein the main transformer comprises a first main transformer Z1 and a second main transformer Z2, and the bus comprises a first bus M1 and a second bus M2; the first bus M1 is connected with the secondary side of the first main transformer Z1, and the second bus M2 is connected with the secondary side of the second main transformer Z2; a communication switch DL1 is arranged between the first bus M1 and the second bus M2; each bus is connected with a plurality of feeders and a grounding transformer, and the grounding transformer is grounded through a small resistor; a switch is arranged between each bus and the main transformer, the grounding transformer and the feeder line;
referring to fig. 1, the fault location and bus method includes:
s110, collecting simulation information and switch information of a fault positioning and bus protection system;
specifically, analog information and switching information of the secondary side of the first main transformer Z1 and the secondary side of the second main transformer Z2 are collected.
S120, determining the area where the fault point is located according to the simulation information;
specifically, the fault area is judged according to the collected simulation information of the secondary side of the first main transformer Z1 and the secondary side of the second main transformer Z2.
And S130, controlling the switch in the area where the fault point is located to be switched off according to the area where the fault point is located and the switch information.
Specifically, the switching of the fault area is controlled to be switched off according to the fault area and the collected switching information of the secondary side of the first main transformer Z1 and the secondary side of the second main transformer Z2.
The fault location and bus protection method provided by the embodiment of the invention judges the fault location and bus protection system fault area by acquiring the simulation information of the secondary side of the first main transformer Z1 and the secondary side of the second main transformer Z2; and the switch of the fault location and bus protection system fault area is disconnected by collecting the switch information of the secondary side of the first main transformer Z1 and the secondary side of the second main transformer Z2. Therefore, the embodiment of the invention can realize the accurate judgment and the accurate isolation of the fault location and the fault area of the bus protection system.
Fig. 3 is a schematic flow chart of another fault location and bus protection method according to an embodiment of the present invention. Referring to fig. 3, collecting the simulation information and the switching information of the fault locating and bus protection system includes:
s310, collecting simulation information of a fault positioning and bus protection system through a zero sequence current transformer; the wiring mode of the secondary side of a main transformer of the fault positioning and bus protection system is triangular wiring; the analog information includes three-phase current and zero-sequence current of the secondary side of the main transformer, three-phase current and zero-sequence current of each feeder, three-phase current of the primary side of the grounding transformer, zero-sequence current of the small resistor of the secondary side of the grounding transformer, and each interval capacitive current.
Specifically, the analog information collected by the zero sequence current transformer includes: the magnitude and direction of three-phase current and the magnitude and direction of zero-sequence current of the secondary side of the first main transformer Z1 and the secondary side of the second main transformer Z2; the magnitude and direction of the three-phase current and the magnitude and direction of the zero-sequence current of each feeder line; the magnitude and direction of the three-phase current at the primary side of the grounding transformer; the magnitude and direction of the zero sequence current of the small resistor on the secondary side of the grounding transformer and the magnitude and direction of the capacitive current at each interval.
S320, collecting switch information of a fault positioning and bus protection system; the switch information comprises the switch position of the secondary side of the main transformer, the position of the interconnection switch, the switch position of each feeder line and the switch position of the grounding transformer.
Specifically, the collected switching information includes a switching position of a secondary side of the main transformer, a position of the interconnection switch, a switching position of each feeder line, and a switching position of the grounding transformer. The switch position includes the position of the switch in the fault location and bus protection system and the position of the switch knife switch.
The embodiment of the invention collects the switch information of the fault positioning and bus protection system, and collects the simulation information of the fault positioning and bus protection system through the zero sequence current transformer, thereby realizing the accurate identification of the fault positioning and bus protection system operation state.
Fig. 4 is a schematic flowchart of another fault location and bus protection method according to an embodiment of the present invention. Referring to fig. 4, determining the area where the fault point is located according to the simulation information includes:
s410, determining the fault of the zero sequence current transformer of the grounding transformer according to the three-phase current of the primary side of the grounding transformer and the zero sequence current of the secondary side of the grounding transformer;
specifically, the zero-sequence current is a current generated when the vector sum of three-phase currents is not zero. I.e. the sum of the three phase currents is consistent with the zero sequence current. When the vector sum of the three-phase current on the primary side of the grounding transformer is inconsistent with the zero-sequence current on the secondary side of the grounding transformer, the fault of the zero-sequence current transformer of the grounding transformer can be judged.
S420, determining a bus area fault according to the vector sum of the total zero sequence current of the fault positioning and bus protection system and the zero sequence vector sum threshold value; the bus region faults comprise bus short-circuit faults, dead zone short-circuit faults close to interconnection switches, short-circuit faults of feeder lines close to the bus side and short-circuit faults of switches on the secondary side of a main transformer close to the bus side;
specifically, a zero sequence current transformer in a feeder line of a grounding transformer of the fault location and bus protection system senses a large zero sequence current, zero sequence current transformers of other feeder lines in the fault location and bus protection system sense a small zero sequence current, and a vector sum of the total zero sequence currents of the fault location and bus protection system is calculated according to the magnitude of the zero sequence currents sensed by the zero sequence current transformers in the fault location and bus protection system. At the moment, most of zero-sequence current in the fault positioning and bus protection system flows through a small resistor on the secondary side of the grounding transformer from a fault point and returns to the fault point through the ground to form a main zero-sequence passage; the minimum part forms a capacitive current through the capacitance effect between each feeder line and the ground to form a secondary zero sequence path. The vector sum of the total zero sequence current of the fault location and bus protection system is determined by the zero sequence current flowing through the small resistor on the secondary side of the grounding transformer and each interval capacitive current. At the moment, the zero sequence current flowing through the small resistor on the secondary side of the grounding transformer in the fault positioning and bus protection system has the same direction with each interval capacitive current. Therefore, the vector sum of the total zero sequence current of the fault location and bus protection system is large. Whether the fault occurs in the bus area can be judged by comparing the vector sum of the total zero sequence current of the fault positioning and bus protection system with the zero sequence vector sum threshold value. The zero sequence vector and the threshold value are setting values and are used for fault location and judgment of the fault of the bus protection system. If the vector sum of the total zero sequence current of the fault positioning and bus protection system is greater than the zero sequence vector sum threshold value, the fault area of the fault positioning and bus protection system is a bus area; otherwise, the process is reversed.
Referring to fig. 2, the bus short-circuit fault in the fault location and bus protection system includes faults at points D12 and D22 on the bus; the dead zone short-circuit fault close to the interconnection switch in the fault positioning and bus protection system refers to a fault close to a D0 point of the bus interconnection switch; the short-circuit fault of each feeder line side close to the bus line in the fault positioning and bus protection system comprises faults of a point D17 and a point D27 on the feeder line; the short-circuit fault of the side, close to the bus, of the switch on the secondary side of the main transformer in the fault positioning and bus protection system comprises faults of a point DZ11 and a point DZ21 on the secondary side of the main transformer, close to the switch.
S430, determining that a high-resistance ground fault occurs in a region from a secondary side coil of the main transformer to a switch of the secondary side of the main transformer according to the magnitude and the direction of the zero-sequence current of the secondary side of the main transformer and the zero-sequence current of the small resistor of the secondary side of the grounding transformer;
specifically, zero sequence currents sensed by the low-voltage side of the main transformer and the zero sequence current transformers of the buses in the fault location and bus protection system are increased, the zero sequence current transformers in the feeder line where the grounding transformer of the fault location and bus protection system is located sense large zero sequence currents, the zero sequence current transformers of other feeder lines in the fault location and bus protection system sense small zero sequence currents, and at the moment, most of the zero sequence currents on the low-voltage side of the transformer in the system return to a fault point through the ground through the small resistor on the secondary side of the grounding transformer to form a main zero sequence path. In the main zero sequence path, the direction of the zero sequence current flowing through the small resistor on the secondary side of the grounding transformer is opposite to that of the zero sequence current on the low-voltage side of the main transformer. Therefore, the vector sum of the current addition is cancelled out, the calculation result is close to zero, and therefore it can be judged that a high-resistance ground fault occurs in the region from the secondary side coil of the main transformer to the switch on the secondary side of the main transformer.
Referring to fig. 2, the occurrence of a high-resistance ground fault in the region between the secondary side coil of the main transformer and the switches on the secondary side of the main transformer in the fault location and bus protection system indicates a fault at the DZ11 point and the DZ21 point between the secondary side coil of the main transformer and the switches on the secondary side of the main transformer.
S440, determining that the feeder line has a single-phase earth fault according to the magnitude and the direction of the zero sequence current of the feeder line and the zero sequence current of a small resistor on the secondary side of the grounding transformer; or determining that at least two feeders are in the out-of-station network and a single-phase earth fault occurs.
Specifically, when the zero sequence current sensed by the zero sequence current transformers of the feeder line and the bus in the fault location and bus protection system is increased, the zero sequence current transformer in the feeder line where the grounding transformer of the fault location and bus protection system is located senses a larger zero sequence current, and the zero sequence current transformer at the low-voltage side of the main transformer in the fault location and bus protection system senses a smaller zero sequence current, at this time, the zero sequence current in the system enters the bus from a fault point through the zero sequence current transformer of the feeder line, and the majority of the zero sequence current flows out of the bus through the small resistor at the secondary side of the grounding transformer and returns to the fault point through the ground, so that a main zero sequence path is formed. In the main zero sequence path, the direction of the zero sequence current flowing through the feeder line is opposite to that of the zero sequence current flowing through the small resistor on the secondary side of the grounding transformer. Therefore, the vector sum of the current additions cancels out, and the calculation result approaches zero. The fault can be judged to occur on the feeder line, and the single-phase earth fault of the feeder line or the single-phase earth fault of at least two feeder lines in the out-of-station network can be judged according to the logic calculation.
Referring to fig. 2, at least two feeders in the fault location and bus protection system are in an off-site network and a single-phase earth fault occurs, which means an off-site D18 point fault.
The fault location and bus protection system of the embodiment of the invention monitors the magnitude of the zero sequence current at each position and the direction of the zero sequence current at each position of the fault location and bus protection system through the zero sequence current transformers distributed in the system, performs logical calculation on the monitoring result, judges the fault location and bus protection system fault area according to the position of the generated zero sequence current and the logical calculation result, and realizes accurate identification and location of the fault location and bus protection system fault area.
Fig. 5 is a schematic flowchart of another fault location and bus protection method according to an embodiment of the present invention. Referring to fig. 5, determining a zero sequence current transformer fault of the grounding transformer according to the three-phase current of the primary side of the grounding transformer and the zero sequence current of the secondary side of the grounding transformer includes:
s510, calculating the sum of three-phase currents on the primary side of the grounding transformer according to the three-phase currents on the primary side of the grounding transformer;
specifically, the vector sum of the three-phase currents is calculated from the three-phase currents on the primary side of the grounding transformer, and defined as I jd 。
And S520, comparing the sum of the three-phase current of the primary side of the grounding transformer with the zero-sequence current of the secondary side of the grounding transformer, and judging the fault states of the current transformer of the primary side of the grounding transformer, the zero-sequence current transformer of the secondary side of the grounding transformer and the internal of the grounding transformer according to the comparison result.
Specifically, the zero sequence current of the secondary side of the grounding transformer is defined as I j0 And summing the three-phase current vectors of the primary side of the grounding transformer jd Zero sequence current I with secondary side of grounding transformer j0 And (6) comparing. Determining a current transformer on a primary side of the grounding transformer, a zero-sequence current transformer on a secondary side of the grounding transformer, and an internal fault state of the grounding transformer based on the comparison result。
The embodiment of the invention adds the three-phase current vector sum I of the primary side of the grounding transformer jd Zero sequence current I of secondary side of grounding transformer j0 And comparing, and judging the fault states of the current transformer on the primary side of the grounding transformer, the zero sequence current transformer on the secondary side of the grounding transformer and the internal part of the grounding transformer according to the comparison result, thereby realizing the accurate identification and positioning of the fault area of the fault positioning and bus protection system.
Optionally, comparing the sum of the three-phase currents on the primary side of the grounding transformer with the zero-sequence current on the secondary side of the grounding transformer, and determining the fault states of the current transformer on the primary side of the grounding transformer, the zero-sequence current transformer on the secondary side of the grounding transformer, and the internal of the grounding transformer according to the comparison result, includes: i when jd -I j0 I1>I z1 Then, determining the internal faults of the zero sequence current transformer on the secondary side of the grounding transformer and the grounding transformer; wherein, I z1 As a setting value, I jd Is the sum of the three-phase currents on the primary side of the grounding transformer, I j0 Is the zero sequence current of the secondary side of the grounding transformer.
Specifically, the zero-sequence current is a current generated when the vector sum of three-phase currents is not zero. I.e. the sum of the three phase currents is consistent with the zero sequence current. In addition, I z1 For setting values for judging I jd And I j0 Whether they are consistent, when I jd -I j0 I1>I z1 When the current is zero, the sum of the three-phase currents on the primary side of the grounding transformer is not consistent with the zero-sequence current on the secondary side of the grounding transformer.
The embodiment of the invention utilizes the sum of three-phase current at the primary side of the grounding transformer and the logical operation result of zero-sequence current at the secondary side of the grounding transformer and I z1 The comparison of (4) determines whether the sum of the three-phase currents on the primary side of the grounding transformer is consistent with the zero-sequence current on the secondary side of the grounding transformer. Thereby realizing the fault state of the current transformer on the primary side of the grounding transformer, the zero sequence current transformer on the secondary side of the grounding transformer and the inside of the grounding transformerAnd (4) judging.
Optionally, determining a bus area fault according to the vector sum of the total zero-sequence current of the fault location and bus protection system and the zero-sequence vector sum threshold value, including:
comparing the vector sum of the total zero sequence current of the fault positioning and bus protection system with the zero sequence vector sum threshold value to generate a comparison result;
and determining the fault of the bus area according to the comparison result.
Specifically, a zero sequence current transformer in a feeder line of a grounding transformer of the fault location and bus protection system senses a large zero sequence current, zero sequence current transformers of other feeder lines in the fault location and bus protection system sense a small zero sequence current, and the total zero sequence current vector sum of the fault location and bus protection system is calculated according to the magnitude of the zero sequence current sensed by the zero sequence current transformers in the fault location and bus protection system. At the moment, most of zero-sequence current in the fault positioning and bus protection system flows through a small resistor on the secondary side of the grounding transformer from a fault point and returns to the fault point through the ground to form a main zero-sequence passage; the minimum part forms a capacitive current through the capacitance effect between each feeder line and the ground to form a secondary zero sequence path. The vector sum of the total zero sequence current of the fault location and bus protection system is determined by the zero sequence current flowing through the small resistor on the secondary side of the grounding transformer and each interval capacitive current. At the moment, the zero sequence current flowing through the small resistor on the secondary side of the grounding transformer in the fault positioning and bus protection system has the same direction as the capacitive current of each interval. Therefore, the vector sum of the total zero sequence current of the fault location and bus protection system is large. Defining the vector sum of total zero sequence currents of the fault location and bus protection system as I 0 . Whether the fault occurs in the bus area can be judged by comparing the vector sum of the total zero sequence current of the fault positioning and bus protection system with the zero sequence vector sum threshold value. When I is 0 >I z3 If so, the fault of the fault positioning and bus protection system occurs in a bus area, otherwise, the fault positioning and bus protection system does not occur in the bus area; wherein, I z3 The zero sequence vector and the threshold value are zero sequence vectors and the threshold value is a setting value. The embodiment of the invention locates the fault and the busAnd comparing the vector sum of the total zero sequence current of the protection system with the zero sequence vector sum threshold value to judge whether the fault is positioned and the bus area of the bus protection system has a fault. And when the vector sum of the total zero sequence current of the fault positioning and bus protection system is greater than the zero sequence vector sum threshold value, the fault area of the fault positioning and bus protection system is a bus area, otherwise, the fault positioning and bus protection system realizes the accurate identification and positioning of the fault area.
Optionally, determining a high-resistance ground fault in a region between a secondary side coil of the main transformer and a switch of the secondary side of the main transformer according to the magnitude and direction of the zero-sequence current of the secondary side of the main transformer and the zero-sequence current of the small resistor of the secondary side of the grounding transformer, includes: comparing the zero sequence current of the secondary side of the main transformer with the zero sequence current of the small resistor of the secondary side of the grounding transformer; and when the direction of the zero sequence current of the secondary side of the main transformer is opposite to that of the zero sequence current of the small resistor of the secondary side of the grounding transformer, and the vector sum of the direction of the zero sequence current of the secondary side of the main transformer and the direction of the zero sequence current of the small resistor of the secondary side of the grounding transformer is zero, judging the high-resistance grounding fault in the area from the coil of the secondary side of the main transformer to the switch of the secondary side of the main transformer.
Specifically, zero sequence currents sensed by a low-voltage side of a main transformer and zero sequence current transformers of a bus in the fault location and bus protection system are increased, a zero sequence current transformer in a feeder line where a grounding transformer of the fault location and bus protection system is located senses a large zero sequence current, zero sequence current transformers of other feeder lines in the fault location and bus protection system sense a small zero sequence current, and most of the zero sequence current on the low-voltage side of the transformer in the system returns to a fault point through the ground through a small resistor on the secondary side of the grounding transformer to form a main zero sequence path; the minimum part forms a capacitive current through the capacitance effect between the feed line and the ground to form a secondary zero-sequence path. In the main zero sequence path, the direction of the zero sequence current flowing through the small resistor on the secondary side of the grounding transformer is opposite to that of the zero sequence current on the low-voltage side of the main transformer. Thus, the vector sum of the current additions cancels out, the meterThe calculation result is close to zero. Defining the zero sequence current of the secondary side of the main transformer as I 10 Defining the vector sum of every interval zero sequence current on the bus as I 0 When the zero sequence current of the low-voltage side of the main transformer is offset with the zero sequence current vector sum of the small resistance of the secondary side of the grounding transformer, I 0 The value of (1) is the vector sum of zero sequence currents on other feed lines connected with the bus, the vector sum of the zero sequence currents is smaller, and the directions of the zero sequence currents are both outflow buses. When I is 0 <I z3 And I 10 I1>I z3 Wherein, I 0 As the vector sum of the zero-sequence currents at intervals on the bus, I 10 Is the zero sequence current value of the low voltage side of the main transformer, I z3 And when the zero sequence vector and the threshold value are obtained and the zero sequence current direction of the low-voltage side of the transformer is the flowing bus, judging that the fault occurs in a region from a main transformer triangle side coil to a low-voltage switch, namely, a high-resistance grounding fault occurs in a region from a secondary side coil of the main transformer to a switch of the secondary side of the main transformer.
The embodiment of the invention monitors the magnitude and the direction of the zero sequence current of the secondary side of the main transformer and the zero sequence current of the small resistor of the secondary side of the grounding transformer, and the vector sum and the I of the zero sequence current of the secondary side of the main transformer and the zero sequence current of each interval on a bus z3 And (3) comparing, judging whether the area from the main transformer triangle side coil to the step-down switch has a fault, and realizing the accurate identification and positioning of the fault area of the fault positioning and bus protection system.
Optionally, determining that the feeder line has a single-phase ground fault according to the magnitude and direction of the zero-sequence current of the feeder line and the zero-sequence current of the small resistor on the secondary side of the grounding transformer; or, determining that at least two feeders form a ring network and a single-phase earth fault occurs outside the station, including: comparing the zero sequence current of the feeder line with the zero sequence current of a small resistor on the secondary side of the grounding transformer; when the direction of the zero sequence current of the feed line is opposite to that of the zero sequence current of the small resistor on the secondary side of the grounding transformer, the vector sum of the zero sequence current of the feed line and the zero sequence current of the small resistor on the secondary side of the grounding transformer is zero, and the maximum value of the zero sequence current of the feed line is greater than X%. I j0 Time, judgeThe feeder line has single-phase earth fault, or at least two feeder lines form a ring network and have single-phase earth fault outside the station; wherein, X% is percentage, when the fault location and bus protection system has no outer ring network of the station, X% =80% is set; when at most two feeders on the same section of bus are in an off-station ring network, setting X% =40%; when at most three feeders on the same section of bus are in the out-station ring network, X% =30% is set.
Specifically, when the zero sequence current sensed by the zero sequence current transformers of the feeder line and the bus in the fault location and bus protection system increases, the zero sequence current transformer in the feeder line where the grounding transformer of the fault location and bus protection system is located senses a larger zero sequence current, and the zero sequence current transformer at the low-voltage side of the main transformer in the fault location and bus protection system senses a smaller zero sequence current, at this moment, the zero sequence current in the system enters the bus from a fault point through the zero sequence current transformer of the feeder line, and most of the zero sequence current flows out of the bus through a small resistor at the secondary side of the grounding transformer and returns to the fault point through the ground, so as to form a main zero sequence path; the minimum part forms a capacitive current through the capacitance effect between each feeder line and the ground to form a secondary zero sequence path. In the main zero sequence path, the direction of the zero sequence current flowing through the feeder line is opposite to that of the zero sequence current flowing through the small resistor on the secondary side of the grounding transformer. Therefore, the vector sums of the current additions cancel out, and the calculation result approaches zero. Since the vector sum of the zero sequence current flowing through the feed line and the zero sequence current flowing through the small resistor on the secondary side of the grounding transformer is cancelled, I at this time 0 The value of (b) is the vector sum of the zero sequence current on the low voltage side of the main transformer and the zero sequence current on the non-faulted feeder, which is small. And because the low-voltage side of the main transformer does not break down, the zero sequence current value of the low-voltage side of the main transformer is smaller. Because two feeders form a ring network outside a station and a single-phase earth fault occurs, the total zero-sequence current vector sum of the fault location and bus protection system, the zero-sequence current value of the low-voltage side of the main transformer and the maximum value of the zero-sequence current of the feeder are larger than X%. I j0 And judging the fault condition of the feeder line. Referring to fig. 2, taking the first main transformer Z1 side as an example,when I is 0 <I z3 I 10 I1<I z3 And max { I 12 ，I 33 ，I 14 }>X％*I j0 And in time, the feeder line of the fault positioning and bus protection system has a fault. Wherein, I 0 Vector sum of total zero sequence currents for fault location and bus protection system, I 10 Is the zero sequence current value of the low voltage side of the main transformer, I z3 Is the sum of the zero sequence vectors and the threshold value, I 12 、I 33 、I 14 Zero-sequence currents induced by the zero-sequence current transformer T12, the zero-sequence current transformer T13 and the zero-sequence current transformer T14 on the first main transformer Z1 side are respectively. When the fault location and bus protection system does not have a station external ring network, setting X% =80%; when two feeder lines on the same section of bus are in an off-station ring network, zero sequence current generated by a fault point is shunted by two feeder lines of the ring network, and X% =40% is set; when three feeders on the same section of bus are in an off-station looped network, zero sequence current generated by a fault point is shunted by three feeders of the looped network, and X% =30% is set.
According to the embodiment of the invention, whether the maximum value of the zero sequence current passing through the feeder line is larger than X%. I j0 The fault condition of the feeder line is judged, and the X% value is set according to the fault location and the existence of the station external ring network in the bus protection system, so that the situation that the zero sequence protection fixed value of the feeder line cannot be reached due to the shunting of the station external ring network is avoided, and the judgment that the single-phase earth fault of the feeder line and the ring network and the single-phase earth fault of at least two feeder line stations are formed is realized.
Optionally, controlling the switch located in the area where the fault point is located to be turned off according to the area where the fault point is located and the switch information, including: when the zero sequence current transformer of the grounding transformer fails, controlling a switch at the primary side of the grounding transformer to be switched off, and locking the protection of the grounding transformer; when the bus area has a fault, controlling the switch of the bus area to be switched off after a level difference, and locking the standby automatic switching-in device; when a high-resistance ground fault occurs in a region from a secondary side coil of the main transformer to a switch on the secondary side of the main transformer, the switch on the secondary side of the main transformer is controlled to be switched off after a level difference; when the feeder line has single-phase earth fault or at least two feeder lines are in the outer ring network of the station and have single-phase earth fault, the switch of the feeder line with fault is controlled to be switched off after a level difference, and the reclosing of the feeder line is locked.
According to the embodiment of the invention, the obtained fault area is judged and the switch of the fault area is disconnected, and when the zero sequence current transformer of the grounding transformer has a fault, the switch on the primary side of the grounding transformer is disconnected; when the bus area has a fault, the switch of the bus area is disconnected, and the standby automatic switching device is locked, so that the secondary impact on the bus is reduced; and when the high-resistance grounding fault exists in the region from the secondary side coil of the main transformer to the switch on the secondary side of the main transformer, the switch on the secondary side of the main transformer is disconnected. The embodiment realizes accurate isolation of the fault area and reduces the fault influence range.
Referring to fig. 2, the fault location and bus protection system includes: the main transformer comprises a first main transformer Z1 and a second main transformer Z2, and the bus comprises a first bus M1 and a second bus M2; the first bus M1 is connected with the secondary side of the first main transformer Z1, and the second bus M2 is connected with the secondary side of the second main transformer Z2; a communication switch DL1 is arranged between the first bus M1 and the second bus M2; each bus is connected with a plurality of feeders and a grounding transformer, and the grounding transformer is grounded through a small resistor; a switch is arranged between each bus and the main transformer, the grounding transformer and the feeder line; the zero sequence current transformer is used for acquiring simulation information and switching information of a fault positioning and bus protection system; the fault positioning module is used for determining the area where the fault point is located according to the simulation information; and the control module is used for controlling the switch in the area where the fault point is located to be switched off according to the area where the fault point is located and the switch information. The fault location and bus protection system provided in this embodiment is used to execute the fault location and bus protection method, and has the beneficial effects of the fault location and bus protection method provided in any of the above embodiments, and details are not repeated here.
It should be understood that various forms of the flows shown above may be used, with steps reordered, added, or deleted. For example, the steps described in the present invention may be executed in parallel, sequentially, or in different orders, and are not limited herein as long as the desired results of the technical solution of the present invention can be achieved.
The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made, depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A fault location and bus protection method is characterized in that the method is applied to a fault location and bus protection system, the fault location and bus protection system at least comprises a main transformer and a bus, the main transformer comprises a first main transformer and a second main transformer, and the bus comprises a first bus and a second bus; the first bus is connected with the secondary side of the first main transformer, and the second bus is connected with the secondary side of the second main transformer; a communication switch is arranged between the first bus and the second bus; each bus is connected with a plurality of feeders and a grounding transformer, and the grounding transformer is grounded through a small resistor; a switch is arranged between each bus and the main transformer, the grounding transformer and the feeder;
the method comprises the following steps:
collecting simulation information and switch information of a fault positioning and bus protection system;
determining the area where the fault point is located according to the simulation information;
and controlling the switch in the area where the fault point is located to be switched off according to the area where the fault point is located and the switch information.
2. The method for fault location and bus protection according to claim 1, wherein the collecting analog information and switch information of the fault location and bus protection system comprises:
acquiring simulation information of a fault positioning and bus protection system through a zero sequence current transformer; the secondary side of the main transformer of the fault positioning and bus protection system is connected in a triangular mode; the analog information comprises three-phase current and zero-sequence current of the secondary side of the main transformer, three-phase current and zero-sequence current of each feeder line, three-phase current of the primary side of a grounding transformer, zero-sequence current of a small resistor of the secondary side of the grounding transformer and interval capacitive current;
collecting the switch information of the fault positioning and bus protection system; the switching information includes a switching position of the secondary side of the main transformer, a position of the interconnection switch, a switching position of each feeder line, and a switching position of the grounding transformer.
3. The method for fault location and bus protection according to claim 2, wherein the determining the area where the fault point is located according to the simulation information comprises:
determining the fault of a zero sequence current transformer of the grounding transformer according to the three-phase current on the primary side of the grounding transformer and the zero sequence current on the secondary side of the grounding transformer;
determining a bus area fault according to the vector sum of the total zero sequence current of the fault positioning and bus protection system and the zero sequence vector sum threshold value; the bus region faults comprise bus short-circuit faults, dead zone short-circuit faults close to interconnection switches, short-circuit faults of feeder lines close to the bus side and short-circuit faults of switches on the secondary side of the main transformer close to the bus side;
determining that a high-resistance ground fault occurs in a region from a secondary side coil of the main transformer to a switch of a secondary side of the main transformer according to the magnitude and the direction of the zero-sequence current of the secondary side of the main transformer and the zero-sequence current of the small resistor of the secondary side of the grounding transformer;
determining that the feeder line has a single-phase ground fault according to the magnitude and direction of the zero-sequence current of the feeder line and the zero-sequence current of the small resistor on the secondary side of the grounding transformer; or determining that at least two feeders are outside the station external network and generating single-phase earth fault.
4. The method for fault location and bus protection according to claim 3, wherein the determining the fault of the zero sequence current transformer of the grounding transformer according to the three-phase current of the primary side of the grounding transformer and the zero sequence current of the secondary side of the grounding transformer comprises:
calculating the sum of the three-phase currents on the primary side of the grounding transformer according to the three-phase currents on the primary side of the grounding transformer;
and comparing the sum of the three-phase currents on the primary side of the grounding transformer with the zero-sequence current on the secondary side of the grounding transformer, and judging the fault states of the current transformer on the primary side of the grounding transformer, the zero-sequence current transformer on the secondary side of the grounding transformer and the inside of the grounding transformer according to the comparison result.
5. The method according to claim 3, wherein the comparing the sum of three-phase currents on the primary side of the grounding transformer with the zero-sequence current on the secondary side of the grounding transformer, and determining the fault state of the current transformer on the primary side of the grounding transformer, the zero-sequence current transformer on the secondary side of the grounding transformer, and the internal part of the grounding transformer according to the comparison result comprises:
i when jd -I j0 I1>I z1 Then, judging the zero sequence current transformer on the secondary side of the grounding transformer and the internal fault of the grounding transformer; wherein, I z1 Is a setting value, I jd Is the sum of the three-phase currents of the primary side of the grounding transformer, I j0 Is the zero sequence current of the secondary side of the grounding transformer.
6. The method for fault location and bus protection according to claim 3, wherein the determining the bus region fault according to the vector sum of the total zero sequence current of the fault location and bus protection system and the zero sequence vector sum threshold value comprises:
comparing the vector sum of the total zero sequence current of the fault positioning and bus protection system with the zero sequence vector sum threshold value to generate a comparison result;
and determining the fault of the bus area according to the comparison result.
7. The method for fault location and bus protection according to claim 3, wherein said determining a high-resistance ground fault in a region between a secondary side coil of a main transformer to a switch on a secondary side of said main transformer according to a magnitude and a direction of a zero-sequence current on the secondary side of the main transformer and a zero-sequence current of a small resistor on the secondary side of said grounding transformer comprises:
comparing the zero sequence current of the secondary side of the main transformer with the zero sequence current of the small resistor of the secondary side of the grounding transformer;
and when the direction of the zero sequence current of the secondary side of the main transformer is opposite to that of the zero sequence current of the small resistor of the secondary side of the grounding transformer, and the vector sum of the direction of the zero sequence current of the secondary side of the main transformer and that of the zero sequence current of the small resistor of the secondary side of the grounding transformer is zero, judging the high-resistance grounding fault in the area from the coil of the secondary side of the main transformer to the switch of the secondary side of the main transformer.
8. The fault location and bus protection method according to claim 3, wherein the feeder line is determined to have a single-phase ground fault according to the magnitude and direction of the zero sequence current of the feeder line and the zero sequence current of the small resistor on the secondary side of the grounding transformer; or, determining that at least two feeders form a ring network and a single-phase earth fault occurs outside the station, including:
comparing the zero sequence current of the feeder line with the zero sequence current of the small resistor on the secondary side of the grounding transformer;
when the direction of the zero sequence current of the feeder line is opposite to that of the zero sequence current of the small resistor on the secondary side of the grounding transformer, the vector of the zero sequence current of the feeder line and the zero sequence current of the small resistor on the secondary side of the grounding transformerThe sum is zero, and the maximum value of the zero sequence current of the feeder line is more than X%. I j0 When the feeder line is in single-phase ground fault, judging that the feeder line has single-phase ground fault, or at least two feeder lines form a ring network and have single-phase ground fault outside the station; wherein, X% is percentage, and when the fault location and bus protection system has no external ring network in the station, X% =80% is set; when two feeders on the same section of bus are in an off-station ring network, setting X% =40%; when three feeders on the same section of bus are in an off-station ring network, X% =30% is set.
9. The fault location and bus protection method according to claim 3, wherein the controlling the switch located in the area where the fault point is located to be turned off according to the area where the fault point is located and the switch information includes:
when the zero sequence current transformer of the grounding transformer fails, controlling a switch at the primary side of the grounding transformer to be switched off, and locking the protection of the grounding transformer;
when the bus area has a fault, controlling a switch of the bus area to be switched off after a level difference, and locking a standby automatic switching-in device;
when the high-resistance grounding fault occurs in the area from the secondary side coil of the main transformer to the switch of the secondary side of the main transformer, the switch of the secondary side of the main transformer is controlled to be switched off after a step difference;
when the feeder line has a single-phase earth fault, or at least two feeder lines are in an out-of-station network and have a single-phase earth fault, controlling the switch of the faulty feeder line to be switched off after a level difference, and locking the reclosure of the feeder line.
10. A fault locating and bus protection system, comprising:
a main transformer and a bus bar,
the main transformers comprise a first main transformer and a second main transformer, and the bus comprises a first bus and a second bus; the first bus is connected with the secondary side of the first main transformer, and the second bus is connected with the secondary side of the second main transformer; a communication switch is arranged between the first bus and the second bus; each bus is connected with a plurality of feeders and a grounding transformer, and the grounding transformer is grounded through a small resistor; a switch is arranged between each bus and the main transformer, the grounding transformer and the feeder;
the zero sequence current transformer is used for acquiring simulation information and switching information of a fault positioning and bus protection system;
the fault positioning module is used for determining the area where the fault point is located according to the simulation information;
and the control module is used for controlling the switch in the area where the fault point is located to be switched off according to the area where the fault point is located and the switch information.
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