CN106019054B - Localization method suitable for DC ice melting line single phase grounding failure - Google Patents
Localization method suitable for DC ice melting line single phase grounding failure Download PDFInfo
- Publication number
- CN106019054B CN106019054B CN201610460240.9A CN201610460240A CN106019054B CN 106019054 B CN106019054 B CN 106019054B CN 201610460240 A CN201610460240 A CN 201610460240A CN 106019054 B CN106019054 B CN 106019054B
- Authority
- CN
- China
- Prior art keywords
- phase
- current
- fault
- ice melting
- line
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000002844 melting Methods 0.000 title claims abstract description 30
- 230000008018 melting Effects 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 17
- 230000004807 localization Effects 0.000 title abstract 2
- 230000005540 biological transmission Effects 0.000 claims description 22
- 230000009466 transformation Effects 0.000 claims description 8
- 238000004364 calculation method Methods 0.000 description 8
- 238000004088 simulation Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000012795 verification Methods 0.000 description 3
- 239000004020 conductor Substances 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 238000013024 troubleshooting Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 101150050759 outI gene Proteins 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
-
- 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
- G01R31/085—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution lines, e.g. overhead
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/088—Aspects of digital computing
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Locating Faults (AREA)
Abstract
The invention discloses a kind of localization methods suitable for DC ice melting line single phase grounding failure; this method is by judging whether the positive and negative electrode current of three-phase current and DC side of exchange side in direct current ice melting system fairing meets protection act equation; corresponding differential protection action is carried out with corresponding; the protection act equation effectively reacts the various failures in fairing protection zone, and has the function of the positioning of failure bridge.The braking function of this protection further contemplates the influence of two measuring loop current transformer out-of-balance currents, is improved to the braking function of traditional valve short circuit protection, becomes the braking function of two broken-line types, improves the reliability of protection.
Description
Technical Field
The invention relates to the technical field of power transmission line protection, in particular to a positioning method suitable for a single-phase earth fault of a direct-current ice melting line.
Background
The direct-current ice melting system mainly applies direct-current voltage to the power transmission line and performs short circuit at the tail end of the power transmission line, so that the lead is heated to melt ice on the power transmission line, the phenomenon that the pole and the line of the line fall due to icing is avoided, and the direct-current ice melting system has great significance on power transmission safety of a power grid. The ice melting device is basically provided with current transverse difference, voltage transverse difference, low voltage, overvoltage and line impedance monitoring protection as the protection of a direct current line aiming at the protection of the ice melting line at present. The impedance monitoring protection based on the ratio of the effective values of the voltage and the current of the ice melting line cannot accurately reflect the fault position, so that the difficulty of operation and maintenance personnel in fault troubleshooting is increased.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a positioning method suitable for a single-phase earth fault of a direct-current ice melting line, so as to accurately position the fault of a power transmission line and solve the problem of difficulty in troubleshooting of operation and maintenance personnel.
In order to achieve the purpose, the invention adopts the technical scheme that:
a positioning method suitable for single-phase earth fault of a direct-current ice melting line comprises the following steps:
respectively connecting the positive electrode and the negative electrode of a converter station with two phases of a three-phase alternating current circuit, suspending the other phase, short-circuiting the tail end of the three-phase circuit, setting the two connected phases as an a phase and a c phase, setting the suspended phase as a b phase, and setting the total length of the circuit as L;
measuring three-phase current at k end of ice melting alternating current wire connected with direct current ice melting systemAnd k-terminal three-phase voltage
Decoupling a time domain transmission equation of the uniform power transmission line by adopting a coulomb-bell transformation, and respectively calculating the time domain transmission equation of the uniform power transmission line according to the moduli after decoupling, wherein the moduli are mutually independent;
assuming that a fault occurs at the F position at a certain moment, the fault distance is x, and the three-phase voltage of the k end is utilized With three-phase currentCalculating the current of each mode on the left side of the F position, and converting the current of each mode into three-phase current through phase-mode inverse transformation
Calculating the grounding impedance at each position along the line:at fault point Xf(x) And (5) performing fault location when the value is 0.
Therefore, the method can be used for positioning the single-phase earth fault of the direct-current ice melting system, and decoupling the 12 pulsating voltage and current by the method to position the fault when the single-phase fault occurs in the direct-current ice melting system. In the positioning process, an even transmission wire equation, the application of coulomb-bell transformation decoupling and kirchhoff current law are fully utilized, and simulation verification is carried out on the basis of the calculation result, so that the method is proved to be capable of effectively improving the accuracy of single-phase earth fault distance measurement of the direct-current ice melting system.
Drawings
FIG. 1 is a schematic diagram of a DC ice melting device in a wiring manner;
FIG. 2 is a schematic diagram of a single-phase earth fault of the DC ice melting device;
FIG. 3 shows the actual ground resistance R with the fault distance x of 50kmf0 Ω, and grounding a reactance simulation graph along the line;
FIG. 4 shows the actual ground resistance R with the fault distance x of 50kmfA line grounding reactance simulation graph is set to be 50 omega;
FIG. 5 shows the actual ground resistance R with the fault distance x of 120kmf0 Ω, and grounding a reactance simulation graph along the line;
FIG. 6 shows the actual ground resistance R with the fault distance x of 120kmfLine-grounded reactance simulation plot 50 Ω.
Detailed Description
The present invention will be further described with reference to the following embodiments.
Fig. 1 is a schematic diagram of a wiring mode of the direct current ice melting device, and the following description shows that the positive and negative poles of the converter station are respectively connected with the a phase and the c phase in the three-phase alternating current line, namely the b phase is suspended (the other two connection modes can form the a phase or the c phase, the principle is similar), the tail end of the three-phase line is short-circuited, and the total length of the line is L. Wherein: is the three-phase voltage at the k end of the line,is a three-phase current of a terminal k,is a three-phase voltage at the end of m,is a three-phase current with m ends.
The time domain transmission equation of the uniform power transmission line is described as follows:
in the formula:
wherein,voltage and current of three phases respectively; rs、RmRespectively the self resistance and the mutual resistance of the line unit length; l iss、LmThe self inductance and the mutual inductance of the line unit length are respectively; gs＝Gd+2Gm，Gd、GmThe conductance of the wire per unit length to the ground and between the wires respectively; cs＝Cd+2Cm，Cd、CmAre respectively a unitThe length of the conductor to ground and the capacitance between the conductors.
Decoupling the matrix by adopting a coulomb-bell transformation, wherein the decoupling matrix is as follows:
decoupling the formula (1.1) by using the formula (1.2) (the formula (1.1) is multiplied by S) to obtain
In the formula:
order to
BalanceIs a component of the 1 mode, and is,is a component of the 2-mode component,is a modulus component of 0, the modulus parameters corresponding to the lines are respectively
Therefore, the modulus transmission line transmission matrix after parameter decoupling is as follows:
the conductance is generally negligible in practical calculations. After decoupling, the equation of the uniform transmission line can be respectively calculated according to the modulus, and the moduli are mutually independent.
When a single-phase earth fault occurs in the transmission line, the example is shown in fig. 2. Except for the direct current component, the content of 12 frequency multiplication alternating current components in the voltage and current amount of the ice melting line is the highest, and the voltage and current phasors used in the following derivation are all 12 frequency multiplication components.
The calculation formula of the voltage and current distribution along the line is as follows:
let z be R + j ω L, y be G + j ω C, respectively, where ω is 12 times the angular velocityAnd (4) degree. Propagation constant gamma and wave impedance Z of line unit lengthcRespectively as follows:
calculating voltage and current distribution along the line by adopting line distribution parameters:
wherein,respectively the voltage and the current at the head end of the line,respectively, the voltage and current at x from the head end of the line.
Calculating non-ice-melting phase k terminal voltage
B-phase k-phase terminal voltage due to non-ice melting phaseCan not be directly measured, but is needed to be used in the calculation of the voltage and the current along the lineThe modulus is calculated from the measured a-phase k-terminal voltage current
From the voltage equation in equation (1.7), the voltage at m is calculated using the 1-mode component
In the formula: l is the total length of the line, an
ByCan obtain
Thereby obtaining the frequency multiplication component of the k-terminal voltage 12 in the non-ice-melting phase.
Fault point left side phase current and phase voltage calculation method
The fault distance is x (x is more than or equal to 0 and less than or equal to l), the k-end three-phase voltage is utilized according to the formula (1.7)With three-phase currentCalculating the current of each mode on the left side of the F position, and converting the current of each mode into three-phase current through phase-mode inverse transformation
In the formula:
the three-phase voltage at F is obtained in the same wayAnd the voltages on the left and right sides of the fault point are the same.
Right side current of fault pointAnd fault point currentCalculation method
Using the two-phase voltage for melting ice at FAnd currentCalculate m place 2 mode voltage
In the formula
According toCan find outIs described in (1).
According to kirchhoff's current law, at the fault point, there is
Fault location
At various locations along the line when the fault distance x varies between 0 and L, as calculated by the preceding calculationAnddue to the existence of grounding resistance at the fault point, the grounding resistance can be calculated at the fault pointAndthe phases are the same to carry out fault location, namely the earth impedance at each position along the line is calculated
Since the transition resistance of the fault point is impedance, X exists at the fault pointf(x) If it is 0, the fault location can be performed according to the imaginary part of the ratio of the fault point voltage to the current being 0.
And carrying out simulation verification on the 12 frequency multiplication component fault location method.
(1) When the fault distance x is 50km, the actual grounding resistance Rf0 and RfWhen the impedance is 50 omega, the simulated line grounding reactance X is obtainedf(x) The values are shown in fig. 3 and 4. According to Xf(x) The fault location is carried out as 0, and R can be obtained from the graphf0 and RfThe measured fault distances were 52.1km and 51.8km, respectively, at 50 Ω.
(2) When the fault distance x is 120km, the actual grounding resistance Rf0 and RfWhen the impedance is 50 omega, the simulated line grounding reactance X is obtainedf(x) The values are shown in fig. 5 and 6. From the graph R can be derivedf0 and RfThe measured fault distances were 119.0km and 118.6km, respectively, at 50 Ω.
(3) Table 1 shows the results of fault location using 12 frequency multiplication components.
Table 112 multiple frequency component fault ranging results
As can be seen from fig. 3-6 and table 1, when the fault location is performed by using 12 frequency multiplication components, the error of the location result is small. The main reason for the error is that there is a certain error in the extraction of the 12-fold frequency component in the measured voltage current. Therefore, in order to improve the measurement accuracy, the measured voltage and current can be processed by a low-pass filter with good filtering effect, and then the fault location is carried out by utilizing the distance measurement principle.
The method aims at the protection of the single-phase fault location method of the direct-current ice melting system, the judgment process fully utilizes the equation of a uniform transmission wire and the application of the coulomb-bell transformation decoupling and kirchhoff current law, and the simulation verification is carried out on the basis of the calculation result, so that the method can effectively improve the accuracy of the single-phase ground fault location of the direct-current ice melting system.
The above detailed description is specific to possible embodiments of the present invention, and the embodiments are not intended to limit the scope of the present invention, and all equivalent implementations or modifications that do not depart from the scope of the present invention are intended to be included within the scope of the present invention.
Claims (1)
1. A positioning method suitable for single-phase earth fault of a direct-current ice melting line is characterized by comprising the following steps:
respectively connecting the positive electrode and the negative electrode of a converter station with two phases of a three-phase alternating current circuit, suspending the other phase, short-circuiting the tail end of the three-phase circuit, setting the two connected phases as an a phase and a c phase, setting the suspended phase as a b phase, and setting the total length of the circuit as L;
measuring three-phase current at k end of ice melting alternating current wire connected with direct current ice melting systemAnd k-terminal three-phase voltage
Decoupling a time domain transmission equation of the uniform power transmission line by adopting a coulomb-bell transformation, and respectively calculating the time domain transmission equation of the uniform power transmission line according to the moduli after decoupling, wherein the moduli are mutually independent;
assuming that a fault occurs at the F position at a certain moment, the fault distance is x, and the three-phase voltage of the k end is utilized With three-phase currentCalculating the current of each mode on the left side of the F position, and converting the current of each mode into three-phase current through phase-mode inverse transformation
Calculating the grounding impedance at each position along the line:at fault point Xf(x) When the fault is equal to 0, fault location is carried out; wherein,andrespectively, the voltage and current at the fault point.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610460240.9A CN106019054B (en) | 2016-06-21 | 2016-06-21 | Localization method suitable for DC ice melting line single phase grounding failure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610460240.9A CN106019054B (en) | 2016-06-21 | 2016-06-21 | Localization method suitable for DC ice melting line single phase grounding failure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106019054A CN106019054A (en) | 2016-10-12 |
| CN106019054B true CN106019054B (en) | 2018-08-28 |
Family
ID=57086479
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610460240.9A Active CN106019054B (en) | 2016-06-21 | 2016-06-21 | Localization method suitable for DC ice melting line single phase grounding failure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106019054B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108469557B (en) * | 2018-03-07 | 2019-03-15 | 西南交通大学 | High voltage direct current transmission device Fault Locating Method based on inverter differential protection |
| CN113013830B (en) * | 2021-03-03 | 2023-06-30 | 贵州电网有限责任公司 | Power transmission line sub-conductor grouping online ice melting distance protection setting impedance calculation method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1933270A (en) * | 2006-01-26 | 2007-03-21 | 天津大学 | Transmission line distance protecting method |
| CN103777114A (en) * | 2014-01-26 | 2014-05-07 | 浙江大学 | Method for recognizing single-phase permanent fault of single-ended electric transmission line with paralleling reactor |
| CN103809082A (en) * | 2014-02-17 | 2014-05-21 | 四川大学 | Distance measurement method for power distribution network single-phase earth fault on the basis of aerial mode traveling wave mutation |
| CN104020395A (en) * | 2014-06-13 | 2014-09-03 | 重庆大学 | Method for accurately measuring distance of single-phase earth fault for small current grounding system |
| CN104391229A (en) * | 2014-12-04 | 2015-03-04 | 山东大学 | Transmission line fault fast phase selection method based on S conversion |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3563902B2 (en) * | 1996-12-09 | 2004-09-08 | ティーエム・ティーアンドディー株式会社 | Current differential protection relay |
-
2016
- 2016-06-21 CN CN201610460240.9A patent/CN106019054B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1933270A (en) * | 2006-01-26 | 2007-03-21 | 天津大学 | Transmission line distance protecting method |
| CN103777114A (en) * | 2014-01-26 | 2014-05-07 | 浙江大学 | Method for recognizing single-phase permanent fault of single-ended electric transmission line with paralleling reactor |
| CN103809082A (en) * | 2014-02-17 | 2014-05-21 | 四川大学 | Distance measurement method for power distribution network single-phase earth fault on the basis of aerial mode traveling wave mutation |
| CN104020395A (en) * | 2014-06-13 | 2014-09-03 | 重庆大学 | Method for accurately measuring distance of single-phase earth fault for small current grounding system |
| CN104391229A (en) * | 2014-12-04 | 2015-03-04 | 山东大学 | Transmission line fault fast phase selection method based on S conversion |
Non-Patent Citations (1)
| Title |
|---|
| 配电网接地故障分析与判断;王智;《中国优秀硕士学位论文全文数据库工程科技Ⅱ辑》;20130115(第1期);第29-30页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106019054A (en) | 2016-10-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100580470C (en) | Phase amount and zero sequence amount combined realization powerline both-end distance measuring method | |
| CN109283430B (en) | Power distribution network fault location method based on voltage distribution principle | |
| CN102175954B (en) | Circuit inter-phase fault single-end ranging method | |
| CN103207352B (en) | Route selection impedance magnitude characteristic is utilized to realize wire selection method for power distribution network single phase earthing failure | |
| CN102135571B (en) | Anti-interference measurement method for zero sequence impedance of super-high-voltage/ultrahigh-voltage multi-loop power transmission line | |
| CN109444657B (en) | Method for positioning high-resistance grounding fault section of power distribution network | |
| CN102129011B (en) | Single-ended interphase fault location method for distributed capacitance current and fault resistance resistant line | |
| CN103245878B (en) | A kind of transmission line one-phase earth fault method of single end distance measurement | |
| CN103163433A (en) | Method for monitoring insulation condition of generator stator and power distribution network on line and performing fault line selection | |
| CN103809079A (en) | Double-end high frequency impedance type fault ranging method suitable for direct current distribution network | |
| CN105652156B (en) | Ultrahigh voltage alternating current transmission lines single-phase earthing voltage-phase is mutated distance measuring method | |
| CN105842582B (en) | Flexible direct current circuit fault distance measurement based on EMTR | |
| CN103293445B (en) | Distribution parameter measurement impedance magnitude characteristic is utilized to realize circuit inter-phase fault single-end ranging | |
| CN106019054B (en) | Localization method suitable for DC ice melting line single phase grounding failure | |
| CN103743995B (en) | A kind of method of voltage DC ground electrode circuit fault based on T-shaped equivalent model range finding | |
| CN103743996A (en) | Pi-type equivalent circuit based direct current earth electrode line fault location method | |
| CN103323739B (en) | Based on distribution parameter measurement impedance magnitude characteristic circuit inter-phase fault single-end ranging | |
| CN103424627B (en) | The method of double-end measurement parallel grid line zero-sequence impedance | |
| CN105242135B (en) | Three-phase power transformer on-line parameter identification device and its realize algorithm | |
| CN103592569A (en) | Extra-high voltage direct-current transmission line fault location method based on high frequency value attenuation characteristics | |
| CN103163427B (en) | Method for realizing line single-phase earth fault single-terminal fault locating by using real part of voltage drop along line | |
| CN109188181A (en) | Network voltage transformer secondary circuit neutral conductor virtual connection judgment method | |
| CN103245890A (en) | Line single-phase ground fault single-terminal location method capable of preventing influences of both transitional resistance and load current | |
| CN103245876A (en) | Method for realizing line interphase fault single-ended distance measurement by means of real part characteristics of voltage drop | |
| CN103217628A (en) | Electric transmission line phase fault single-ended distance measuring method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |