CN116953591A - Relay protection terminal loop abnormality identification method, equipment and medium - Google Patents

Relay protection terminal loop abnormality identification method, equipment and medium Download PDF

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Publication number
CN116953591A
CN116953591A CN202310747172.4A CN202310747172A CN116953591A CN 116953591 A CN116953591 A CN 116953591A CN 202310747172 A CN202310747172 A CN 202310747172A CN 116953591 A CN116953591 A CN 116953591A
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China
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line
target
switch
phase
phase current
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Inventor
梁宇文
胡兵
陈栋
李玉平
秦昌嵩
张玮
齐以年
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Nanjing SAC Automation Co Ltd
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Nanjing SAC Automation Co Ltd
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Priority to CN202310747172.4A priority Critical patent/CN116953591A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
    • G01R35/02—Testing or calibrating of apparatus covered by the other groups of this subclass of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The application discloses a relay protection terminal loop anomaly identification method, equipment and medium, comprising the following steps: acquiring a three-phase current value of a line of a target distribution substation and an adjacent distribution substation; respectively calculating a line differential flow and a bus differential flow based on the three-phase current values of the line; determining whether a secondary circuit of a target distribution substation is abnormal in CT disconnection based on the line differential current, the bus differential current and the line three-phase current value; acquiring a bus voltage three-phase voltage of a target distribution substation as a first bus voltage, acquiring a bus voltage three-phase voltage of a distribution substation on the opposite side of a line inlet interval of the target distribution substation as a second bus voltage, and calculating line differential pressure; and determining whether the PT of the secondary circuit of the target distribution substation is abnormal or not based on the line differential pressure and the line three-phase current value. The application effectively utilizes the characteristics of communication, accurately judges loop abnormality such as CT, PT disconnection and the like, has less electric quantity required to be acquired by criteria, has high reliability, and relieves the problem of difficult recognition of loop abnormality of the relay protection terminal in the prior art.

Description

Relay protection terminal loop abnormality identification method, equipment and medium
Technical Field
The application relates to the technical field of power system protection and control, in particular to a relay protection terminal loop abnormality identification method, equipment and medium.
Background
The current transformer (Current transformer, CT) and the voltage transformer (Potential transformer, PT) are important elements for guaranteeing safe and stable operation of the power system, when the secondary side of the CT is open, the safety of equipment is endangered, incorrect protection actions are easily caused, and therefore CT disconnection is accurately screened, and the reliability of equipment operation and protection is very important. At present, the corresponding protection is locked by adopting a CT disconnection locking criterion in engineering, and the method is favorable for improving the reliability for the high-voltage protection of double configuration, but the protection is withdrawn due to CT disconnection for the distribution network protection of single configuration. The PT disconnection will affect the functions of the re-voltage direction element, the head switch voltage-losing tripping, the rapid self-healing, the spare power automatic switching and the like, so as to cause protection refusal or misoperation accidents. In summary, the technical problem that the loop abnormality of the relay protection terminal is difficult to identify still exists for the distribution network protection at present.
Disclosure of Invention
The application aims to solve at least one technical problem and provide a relay protection terminal loop abnormality identification method, equipment and medium.
In a first aspect, an embodiment of the present application provides a method for identifying loop anomalies of a relay protection terminal, which is applied to a relay protection terminal of a target power distribution substation; the target distribution substation is one of a plurality of distribution substations between two substations; relay protection terminals between adjacent distribution offices in the plurality of distribution offices are communicated pairwise; comprising the following steps: acquiring a line three-phase current value of the target power distribution substation; the line three-phase current values include: three-phase currents at an inlet wire interval, three-phase currents at a feeder wire interval and three-phase currents of a switch of a power distribution station at the opposite side of the inlet wire interval; calculating a line differential flow and a bus differential flow based on the line three-phase current values; determining whether a secondary circuit of the target power distribution station is abnormal in CT disconnection based on the line differential current, the bus differential current and the line three-phase current value; acquiring a bus voltage three-phase voltage of the target power distribution substation as a first bus voltage three-phase voltage, and acquiring a bus voltage three-phase voltage of the power distribution substation on the opposite side of a wire inlet interval of the target power distribution substation as a second bus voltage three-phase voltage; if the switch position states of the incoming line interval switch of the target power distribution station and the switch position state of the switch of the incoming line interval opposite side power distribution station of the target power distribution station are all at the on-position, calculating line voltage difference based on the first bus three-phase voltage and the second bus three-phase voltage; and determining whether the PT of the secondary circuit of the target distribution substation is abnormal or not based on the line differential pressure and the line three-phase current value.
Further, based on the line three-phase current values, a line differential flow and a bus differential flow are calculated, respectively, including: the line differential stream is calculated by the following equation:the bus differential stream is calculated by the following equation: wherein ,IDL For the line differential flow, I DB For the bus differential flow,/->For the three-phase current of the line interval, +.>Three-phase currents for the feeder line interval, +.>And distributing three-phase current of a switch for the opposite side of the incoming line interval.
Further, the CT disconnection abnormality comprises a line-in interval CT disconnection abnormality and a line-in intervalCT wire breakage abnormality; determining whether a secondary circuit of the target distribution substation is abnormal in CT disconnection based on the line differential current, the bus differential current, and the line three-phase current value, comprising: judging whether the following conditions are satisfied:if yes, determining that the secondary loop incoming line interval CT of the target power distribution substation is abnormal; judging whether the following conditions are satisfied:if yes, determining that the secondary loop feeder interval CT of the target power distribution substation is abnormal; wherein I is set1 To be the phase overcurrent threshold, I set2 For the line differential current threshold, I set3 Is the bus differential current threshold.
Further, calculating a line differential pressure based on the first bus three-phase voltage and the second bus three-phase voltage, comprising: the line differential pressure is calculated by the following equation:wherein DeltaU is the line differential pressure,for the vector value of the first bus three-phase voltage, and (2)>Is a vector value of the second bus three-phase voltage.
Further, determining whether a secondary loop of the target distribution substation is PT disconnection abnormal based on the line differential pressure and the line three-phase current value, includes: judging whether the following conditions are satisfied:if yes, determining that the secondary loop PT of the target power distribution substation is abnormal in disconnection; wherein I is set1 To be the phase overcurrent threshold, U n Operating the power distribution substation for the targetRated voltage>And the three-phase current value of the line is obtained.
Further, the method further comprises the following steps: locking the CT identification function of the target distribution substation if the following conditions are met: the communication is interrupted, and the collected traffic and fault information cannot be transmitted to the opposite-side distribution substation; at least one of the phase-separated currents is greater than a predetermined threshold; locking the PT identification function of the target power distribution substation if the following conditions are met: the communication is interrupted, and the collected traffic and fault information cannot be transmitted to the opposite-side distribution substation; at least one of the phase-separated currents is greater than the predetermined threshold; and the incoming line switches of the target distribution substation are all at the sub-positions.
In a second aspect, the embodiment of the application also provides a relay protection terminal loop abnormality identification method, which is applied to a relay protection terminal of a target trunk line switch; the target trunk line switch is a switch in a plurality of trunk line switches on an overhead line trunk line; a plurality of branch feeder lines are arranged among the trunk line switches; comprising the following steps: acquiring a target three-phase current of the target main line switch, an upstream three-phase current of the target main line switch and a downstream three-phase current of the target main line switch; the upstream three-phase current comprises three-phase currents of an upstream adjacent trunk line switch of the target trunk line switch and three-phase currents of a plurality of branch feeders between the target trunk line switch and the upstream adjacent trunk line switch; the downstream three-phase current comprises a three-phase current of a downstream adjacent trunk line switch of the target trunk line switch and a three-phase current of a plurality of branch feeders between the target trunk line switch and the downstream adjacent trunk line switch; calculating an upstream difference stream and a downstream difference stream based on the target three-phase current, the upstream three-phase current, and the downstream three-phase current; determining whether a switch-interval secondary loop of the target main line switch is abnormal in CT disconnection based on the target three-phase current, the upstream three-phase current, the downstream three-phase current, the upstream differential flow and the downstream differential flow.
Further, determining whether a switch-interval secondary loop of the target main line switch is abnormal in CT disconnection based on the target three-phase current, the upstream three-phase current, the downstream three-phase current, the upstream differential flow, and the downstream differential flow, includes: judging whether the following conditions are satisfied:if yes, determining that the secondary loop CT of the target main line switch is abnormal in disconnection; judging whether the following conditions are satisfied:if yes, determining that a branch feeder switch secondary loop between the target main line switch and the upstream adjacent main line switch has CT disconnection abnormality, wherein the CT disconnection interval is a kth feeder interval; wherein (1)>For the target three-phase current, < > three-phase current, >>Three-phase current for the upstream adjacent main line switch, +.>For three-phase currents of a plurality of branch feeders between the target main line switch and the downstream adjacent main line switch, I D1 For the upstream differential stream, I D2 For the downstream differential stream, I setM For the phase overcurrent threshold of the target trunk switch, I setN For the phase overcurrent threshold of the upstream adjacent trunk line switch, I set4 An overcurrent threshold, I, for each branch feeder upstream of the target trunk switch set5 For the upstream segment differential current threshold, I set6 For the downstream segment differential current threshold, I set7 The no-flow threshold is for the switch interval.
In a third aspect, an embodiment of the present application further provides an electronic device, including: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method according to the first and second aspects when executing the computer program.
In a fourth aspect, embodiments of the present application also provide a computer readable storage medium storing computer instructions which, when executed by a processor, implement the methods of the first and second aspects.
The application provides a relay protection terminal loop abnormality identification method, equipment and medium, which effectively utilize the characteristics of communication, accurately judge loop abnormalities such as CT and PT disconnection, have less electric quantity required to be acquired by criteria and high reliability, and solve the technical problem of difficult relay protection terminal loop abnormality identification in the prior art.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are needed in the detailed description of the embodiments and the prior art will be briefly described below, it being obvious that the drawings in the following description are some embodiments of the application and that other drawings may be obtained from these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flowchart of a method for identifying loop anomalies of a relay protection terminal according to an embodiment of the present application;
fig. 2 is a schematic diagram of a cable transmission line system according to an embodiment of the present application;
FIG. 3 is a flowchart of another method for identifying loop anomalies of a relay protection terminal according to an embodiment of the present application;
fig. 4 is a schematic diagram of an overhead transmission line system according to an embodiment of the present application.
Detailed Description
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
Example 1
Fig. 1 is a flowchart of a method for identifying loop anomalies of a relay protection terminal, which is applied to a relay protection terminal of a target power distribution substation. Fig. 2 is a schematic diagram of a cable transmission line system according to an embodiment of the present application.
As shown in fig. 2, a plurality of distribution stations are interconnected between a substation a and a substation B, each distribution station is provided with a relay protection terminal, and the relay protection terminal has a data acquisition function, a communication function, a phase overcurrent protection function, a line differential function, a bus differential function, a CT disconnection recognition function and the like, and the target distribution station is one of the plurality of distribution stations between two substations (the substation a and the substation B); relay protection terminals between adjacent distribution offices in a plurality of distribution offices are communicated in pairs.
As shown in fig. 1, the method provided by the embodiment of the application specifically includes the following steps:
step S102, obtaining a line three-phase current value of a target power distribution substation; the three-phase current value of the line comprises: three-phase current at line-in intervals, three-phase current at line-in intervals and three-phase current of a switch of the opposite-side distribution substation at line-in intervals.
Specifically, as shown in fig. 2, three-phase currents of line intervals M1 and M2 of a collection target distribution substation of a relay protection terminalAnd the rest of the feeder line spacing m 3..mx three-phase current +.>Three-phase current of switch of opposite-side distribution substation for obtaining incoming line interval M1 through communication>Three-phase current +.>If the communication is interrupted, the M station (i.e. the target distribution station) fails to collect the alternating current amount +.>The alternating current quantity which is transmitted to the N station or can not be collected is +.>Transmitting the power to a K station, and locking the CT identification function of the target power distribution station; if the alternating current quantity of the opposite side station N station is not obtainedThe CT identification function of the opposite side station N station is locked; the same applies to the K station.
M station, N side station and K station are smaller than their respective interval phase overcurrent constant value I according to the collected current set1 If the phase overcurrent is not detected by each station, otherwise, the CT disconnection judging function is blocked by the phase overcurrent out-of-limit station.
Step S104, respectively calculating a line differential flow and a bus differential flow based on the line three-phase current values.
Specifically, the line differential flow is calculated by the following equation:
the bus differential flow is calculated by the following equation:
wherein ,IDL Is a line differential flow; i DB The bus differential flow is the differential current variation and is equal to the absolute value of the sum of the current variation of each connecting unit;three-phase current for line-in interval->Three-phase current for feeder line interval->Three-phase currents for the switches are distributed for opposite sides of the line space.
And step S106, determining whether the secondary circuit of the target distribution substation is abnormal in CT disconnection or not based on the line differential flow, the bus differential flow and the line three-phase current values.
Specifically, in the embodiment of the application, the CT disconnection abnormality comprises a line-incoming interval CT disconnection abnormality and a line-incoming interval CT disconnection abnormality; determining whether a secondary loop of a target distribution substation is abnormal in CT disconnection based on a line differential current, a bus differential current and a line three-phase current value, comprising:
judging whether the following conditions are satisfied:
if yes, determining that the secondary loop incoming line interval CT of the target distribution substation is abnormal.
In the embodiment of the application, after determining that the CT wire breakage abnormality of the wire inlet interval, the opposite side switch current interconnected with the CT wire breakage abnormality is adopted as the wire breakage interval current to participate in bus differential protection calculation, namelyThe M2 interval CT disconnection judging method and the processing method are the same as the M1 interval.
Judging whether the following conditions are satisfied:
if yes, determining that the secondary loop feeder interval CT of the target distribution substation is abnormal; wherein the method comprises the steps of，I set1 Iset2 is the line differential current threshold, iset3 is the bus differential current threshold, which is the phase overcurrent threshold.
In the embodiment of the application, after determining that the feeder line interval CT is abnormal, other interval combined currents of the target distribution substation are adopted as the line interval current to participate in line protection calculation, and the line interval current I is adopted H The phase is opposite to the opposite side switching current that it interconnects.
In particular, the method comprises the steps of,(X. Noteq. Line break interval).
And S108, acquiring the bus voltage three-phase voltage of the target power distribution substation as a first bus three-phase voltage, and acquiring the bus voltage three-phase voltage of the power distribution substation on the opposite side of the incoming line interval of the target power distribution substation as a second bus three-phase voltage.
Specifically, as shown in fig. 2, the first bus three-phase voltage U of the target distribution substation is collected M1 Switch B for collecting incoming line interval M1 M1 Switch B of incoming line interval M2 M2 Is used for obtaining the three-phase voltage U of the second bus on the opposite side station through the communication obtaining interval M1 N1 And switch B N1 Position state of (2), interval M2, three-phase voltage U spaced by the side station K1 And switch B K1 Position state of (2);
first bus three-phase voltage U of target distribution substation collected by each distribution substation M1 Outgoing line switch K M1 Is used for learning the position of the second bus three-phase voltage U switched by the opposite station through communication N1 And incoming line switch K N2 Is a position of (c).
Step S110, if the switch position states of the incoming line interval switch of the target power distribution substation and the switch position state of the switch of the incoming line interval opposite side power distribution substation of the target power distribution substation are all at the on-position, line voltage difference is calculated based on the first bus three-phase voltage and the second bus three-phase voltage.
Specifically, the line differential pressure is calculated by the following equation:
wherein DeltaU is the line differential pressure,for the vector value of the three-phase voltage of the first busbar, < >>Is the vector value of the three-phase voltage of the second bus.
Step S112, determining whether the secondary loop of the target distribution substation is abnormal in PT disconnection based on the line differential pressure and the line three-phase current value.
Specifically, it is determined whether the following condition is satisfied:
if yes, determining that the secondary loop PT of the target power distribution substation is abnormal in disconnection;
wherein ,Iset1 For the phase overcurrent threshold, un is the rated voltage at which the target distribution substation is operating,is the three-phase current value of the line.
In the embodiment of the application, after determining that the PT of the target distribution substation is abnormal, the voltage of the adjacent interconnection station is adopted as the voltage of the target distribution substation to participate in line protection calculation.
Optionally, in an embodiment of the present application, I set1 、I set2 、I set3 The specific numerical value is specifically set according to the line parameters.
Optionally, in an embodiment of the present application, the CT identification function of the target distribution substation is blocked if the following conditions are met: the communication is interrupted, and the collected traffic and fault information cannot be transmitted to the opposite-side distribution substation; at least one of the phase-separated currents is greater than a predetermined threshold;
the PT identification function of the target distribution substation is blocked if the following conditions are satisfied: the communication is interrupted, and the collected traffic and fault information cannot be transmitted to the opposite-side distribution substation; at least one of the phase-separated currents is greater than a predetermined threshold; the incoming line switches of the target distribution substation are all at the branch positions.
In the embodiment of the application, if the voltage difference calculation is satisfied, the voltage difference calculation is performed on the voltage of the target distribution substation and the voltage of the opposite side station when the line interval switch and the line interval opposite side switch of the target distribution substation are simultaneously in the on-position.
According to the relay protection terminal loop abnormality identification method provided by the embodiment of the application, the line current differential is calculated through communication between the station and the opposite station, meanwhile, the CT disconnection is identified through calculating the bus current differential calculation of the station, and the CT disconnection identification cannot be misjudged; after the CT disconnection is identified, the current at the switch interval of the opposite side station is adopted to replace the CT disconnection or other interval current of the opposite side station is adopted to replace the CT disconnection to participate in protection calculation, and protection cannot be withdrawn for the distribution network protection of single configuration. Meanwhile, the PT identification accuracy is high, and the problem that three-phase PT disconnection (idle operation) is difficult to judge under the light load condition can be solved; and after the PT is identified to be disconnected, the voltage of the adjacent station is adopted to replace the disconnection voltage to participate in protection calculation, so that protection is not exited.
Example two
Fig. 3 is a flowchart of another method for identifying loop anomalies of a relay protection terminal, which is applied to a relay protection terminal of a target trunk line switch according to an embodiment of the present application. Fig. 4 is a schematic diagram of an overhead transmission line system according to an embodiment of the present application.
As shown in fig. 4, a plurality of switches are arranged on a main line between a transformer substation a and a transformer substation B, and the target main line switch is a switch in the plurality of main line switches on the main line of the overhead line; a plurality of branch feeder lines are arranged among the plurality of trunk line switches, each trunk line switch is provided with a relay protection terminal, and the relay protection terminals have the functions of data acquisition, communication, phase overcurrent protection, line differential function, CT disconnection identification and the like, and two relay protection terminals are communicated in pairs.
As shown in fig. 3, the method provided by the embodiment of the application specifically includes the following steps:
step S302, a target three-phase current of the target main line switch, an upstream three-phase current of the target main line switch, and a downstream three-phase current of the target main line switch are acquired.
Wherein the upstream three-phase current includes a three-phase current of an upstream adjacent trunk line switch of the target trunk line switch and a three-phase current of a plurality of branch feeders between the target trunk line switch and the upstream adjacent trunk line switch; the downstream three-phase current includes a three-phase current of a downstream adjacent trunk switch of the target trunk switch and a three-phase current of a plurality of branch feeders between the target trunk switch and the downstream adjacent trunk switch.
Specifically, as shown in fig. 4, the relay protection terminal collects the target three-phase current of the target main line switch MAnd three-phase current of upstream adjacent main line switch is collected in a communication mode>And three-phase currents of a plurality of branch feeders between the target main line switch and an upstream adjacent main line switch +.>And collecting three-phase current of the downstream adjacent main line switch in a communication manner +.>And a plurality of branch feeders between the target main line switch and the downstream adjacent main line switch +.>
Step S304 calculates an upstream difference stream and a downstream difference stream based on the target three-phase current, the upstream three-phase current, and the downstream three-phase current.
In particular, using the acquired current, it is computationallyDifferential flow
Calculating downstream differential flow
Step S306, determining whether the secondary circuit of the switch interval of the target main line switch is abnormal due to CT disconnection, based on the target three-phase current, the upstream three-phase current, the downstream three-phase current, the upstream differential current, and the downstream differential current.
Specifically, it is determined whether the following condition is satisfied:
if yes, determining that the secondary loop CT of the target main line switch is abnormal in disconnection.
In the embodiment of the application, if it is determined that the main line switch CT is abnormal, the current of the line protection calculation is performed by using the current of other switches in the upstream section or the current of other switches in the downstream section of the switch M (i.e., the target main line switch).
Specifically, when the main line switch CT is disconnected, other interval current combined currents in the upstream section of the M switch are adopted as the disconnection current, and the value of the disconnection current is(X. Noteq. The disconnection switch); the other interval current of the downstream section of the M switch is adopted, and the value of the current is +.>(X. Noteq. The off-line switch).
Judging whether the following conditions are satisfied:
if so, determining that a branch feeder switch secondary loop between the target main line switch and an upstream adjacent main line switch has CT disconnection abnormality, wherein the CT disconnection interval is the kth feeder interval.
In the embodiment of the application, if the disconnection abnormality of the branch line switch CT is determined, all the switch combined currents in the upstream section of the switch M are adopted as the currents of the disconnection switch to participate in line protection calculation.
Specifically, the current of the switch is selected as the current of the disconnection switch, wherein the current of the disconnection switch is the value of the switching current in the upstream section of the switch M(X. Noteq. The off-line switch).
wherein ,for the target three-phase current +.>Three-phase current for upstream adjacent main line switch, +.>For three-phase current of multiple branch feeders between target main line switch and downstream adjacent main line switch, I D1 As upstream differential flow, I D2 For downstream differential flow, I setM For the phase overcurrent threshold of the target main line switch, I setN I is the phase overcurrent threshold of the upstream adjacent trunk switch set4 For each branch feeder phase overcurrent threshold upstream of the target trunk line switch, I set5 For the upstream segment differential current threshold, I set6 For the downstream segment differential current threshold, I set7 The no-flow threshold is for the switch interval.
Optionally, in an embodiment of the present application, the CT identification function blocking condition: communication is interrupted, and the relay protection terminal at the switch M in the upstream section lacks the current of any switch in the section; at least one main line switch current in the section is greater than I set Or branch line current has at least one switching current greater than I set4 。
Optionally, in an embodiment of the present application, I set 、I set4 、I set5 、I set6 The specific numerical value is specifically set according to the line parameters.
According to the method for identifying the abnormal relay protection terminal loop, provided by the embodiment of the application, the switches on the main line are divided into two sections, and the CT disconnection of the switch on the main line or the CT disconnection of the branch line is identified through the differential calculation of the section current, so that the identification accuracy is high; after the CT disconnection is identified, all the switching currents including the CT disconnection switch interval are used as the currents of the disconnection switch, the protection calculation is participated, and the protection cannot be withdrawn for the distribution network protection of single-set configuration.
The embodiment of the application also provides electronic equipment, which comprises: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method as in embodiment one and embodiment two when executing the computer program.
The embodiment of the application also provides a computer readable storage medium, wherein the computer readable storage medium stores computer instructions which, when executed by a processor, implement the method as in the first and second embodiments.
It will be evident to those skilled in the art that the application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims (10)

1. A relay protection terminal loop abnormality identification method is characterized by comprising the following steps of: relay protection terminal applied to target distribution substation; the target distribution substation is one of a plurality of distribution substations between two substations; relay protection terminals between adjacent distribution offices in the plurality of distribution offices are communicated pairwise; comprising the following steps:
acquiring a line three-phase current value of the target power distribution substation; the line three-phase current values include: three-phase currents at an inlet wire interval, three-phase currents at a feeder wire interval and three-phase currents of a switch of a power distribution station at the opposite side of the inlet wire interval;
calculating a line differential flow and a bus differential flow based on the line three-phase current values;
determining whether a secondary circuit of the target power distribution station is abnormal in CT disconnection based on the line differential current, the bus differential current and the line three-phase current value;
acquiring a bus voltage three-phase voltage of the target power distribution substation as a first bus voltage three-phase voltage, and acquiring a bus voltage three-phase voltage of the power distribution substation on the opposite side of a wire inlet interval of the target power distribution substation as a second bus voltage three-phase voltage;
if the switch position states of the incoming line interval switch of the target power distribution station and the switch position state of the switch of the incoming line interval opposite side power distribution station of the target power distribution station are all at the on-position, calculating line voltage difference based on the first bus three-phase voltage and the second bus three-phase voltage;
and determining whether the PT of the secondary circuit of the target distribution substation is abnormal or not based on the line differential pressure and the line three-phase current value.
2. The method according to claim 1, characterized in that: calculating a line differential flow and a bus differential flow based on the line three-phase current values, respectively, including:
the line differential stream is calculated by the following equation:
the bus differential stream is calculated by the following equation:
wherein ,IDL For the line differential flow, I DB For the differential flow of the bus-bars,for the three-phase current of the incoming line interval,three-phase currents for the feeder line interval, +.>And distributing three-phase current of a switch for the opposite side of the incoming line interval.
3. The method according to claim 2, characterized in that: the CT disconnection abnormality comprises an incoming line interval CT disconnection abnormality and an incoming line interval CT disconnection abnormality; determining whether a secondary circuit of the target distribution substation is abnormal in CT disconnection based on the line differential current, the bus differential current, and the line three-phase current value, comprising:
judging whether the following conditions are satisfied:
if yes, determining that the secondary loop incoming line interval CT of the target power distribution substation is abnormal;
judging whether the following conditions are satisfied:
if yes, determining that the secondary loop feeder interval CT of the target power distribution substation is abnormal;
wherein ,Iset1 To be the phase overcurrent threshold, I set2 For the line differential current threshold, I set3 Is the bus differential current threshold.
4. The method according to claim 1, characterized in that: calculating a line differential voltage based on the first bus three-phase voltage and the second bus three-phase voltage, comprising: the line differential pressure is calculated by the following equation:
wherein DeltaU is the line differential pressure,for the vector value of the first bus three-phase voltage, and (2)>Is a vector value of the second bus three-phase voltage.
5. The method according to claim 4, wherein: determining whether a secondary loop of the target distribution substation is PT disconnection abnormal based on the line differential pressure and the line three-phase current value, comprising:
judging whether the following conditions are satisfied:
if yes, determining that the secondary loop PT of the target power distribution substation is abnormal in disconnection;
wherein ,Iset1 To be the phase overcurrent threshold, U n For the rated voltage at which the target power distribution substation is operating,and the three-phase current value of the line is obtained.
6. The method according to claim 1, characterized in that: further comprises: locking the CT identification function of the target distribution substation if the following conditions are met: the communication is interrupted, and the collected traffic and fault information cannot be transmitted to the opposite-side distribution substation; at least one of the phase-separated currents is greater than a predetermined threshold;
locking the PT identification function of the target power distribution substation if the following conditions are met: the communication is interrupted, and the collected traffic and fault information cannot be transmitted to the opposite-side distribution substation; at least one of the phase-separated currents is greater than the predetermined threshold; and the incoming line switches of the target distribution substation are all at the sub-positions.
7. A relay protection terminal loop abnormality identification method is characterized by comprising the following steps of: relay protection terminal applied to target trunk line switch; the target trunk line switch is a switch in a plurality of trunk line switches on an overhead line trunk line; a plurality of branch feeder lines are arranged among the trunk line switches; comprising the following steps:
acquiring a target three-phase current of the target main line switch, an upstream three-phase current of the target main line switch and a downstream three-phase current of the target main line switch; the upstream three-phase current comprises three-phase currents of an upstream adjacent trunk line switch of the target trunk line switch and three-phase currents of a plurality of branch feeders between the target trunk line switch and the upstream adjacent trunk line switch; the downstream three-phase current comprises a three-phase current of a downstream adjacent trunk line switch of the target trunk line switch and a three-phase current of a plurality of branch feeders between the target trunk line switch and the downstream adjacent trunk line switch;
calculating an upstream difference stream and a downstream difference stream based on the target three-phase current, the upstream three-phase current, and the downstream three-phase current;
determining whether a switch-interval secondary loop of the target main line switch is abnormal in CT disconnection based on the target three-phase current, the upstream three-phase current, the downstream three-phase current, the upstream differential flow and the downstream differential flow.
8. The method according to claim 7, wherein: determining whether a switch-interval secondary loop of the target main line switch is abnormal in CT disconnection based on the target three-phase current, the upstream three-phase current, the downstream three-phase current, the upstream differential flow, and the downstream differential flow, comprising:
judging whether the following conditions are satisfied:
if yes, determining that the secondary loop CT of the target main line switch is abnormal in disconnection;
judging whether the following conditions are satisfied:
if yes, determining that a branch feeder switch secondary loop between the target main line switch and the upstream adjacent main line switch has CT disconnection abnormality, wherein the CT disconnection interval is a kth feeder interval;
wherein ,for the target three-phase current, < > three-phase current, >>Three-phase current for the upstream adjacent main line switch, +.>For three-phase currents of a plurality of branch feeders between the target main line switch and the downstream adjacent main line switch, I D1 For the upstream differential stream, I D2 For the downstream differential stream, I setM For the phase overcurrent threshold of the target trunk switch, I setN For the phase overcurrent threshold of the upstream adjacent trunk line switch, I set4 An overcurrent threshold, I, for each branch feeder upstream of the target trunk switch set5 For the upstream segment differential current threshold, I set6 For the downstream segment differential current threshold, I set7 The no-flow threshold is for the switch interval.
9. An electronic device, comprising: memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the processing method according to any of claims 1-8 when the computer program is executed.
10. A computer readable storage medium storing computer instructions which, when executed by a processor, implement the method of any one of claims 1-8.
CN202310747172.4A 2023-06-21 2023-06-21 Relay protection terminal loop abnormality identification method, equipment and medium Pending CN116953591A (en)

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