CN112130024A - Voltage sag source positioning method for load containing source - Google Patents
Voltage sag source positioning method for load containing source Download PDFInfo
- Publication number
- CN112130024A CN112130024A CN202010715193.4A CN202010715193A CN112130024A CN 112130024 A CN112130024 A CN 112130024A CN 202010715193 A CN202010715193 A CN 202010715193A CN 112130024 A CN112130024 A CN 112130024A
- Authority
- CN
- China
- Prior art keywords
- voltage
- upstream
- downstream
- voltage sag
- source
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 22
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 40
- 238000012544 monitoring process Methods 0.000 claims abstract description 15
- 230000035945 sensitivity Effects 0.000 claims abstract description 8
- 239000000126 substance Substances 0.000 claims description 2
- 238000004445 quantitative analysis Methods 0.000 abstract description 3
- 230000005540 biological transmission Effects 0.000 description 1
- 238000012806 monitoring device Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/088—Aspects of digital computing
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a method for positioning a voltage sag source with a load containing a source. The method comprises three steps: and identifying the source-containing parameters of the upstream and downstream by using a multipoint method based on Thevenin theorem, obtaining a voltage sensitivity equation of the upstream and downstream parameters at the monitoring point, and introducing a weight idea to perform quantitative analysis on the upstream and downstream positioning of the voltage sag source. The invention provides a voltage sag source positioning method based on a multipoint method and sensitivity and used for load containing sources, and the weight idea is introduced to carry out quantitative analysis on the upstream and downstream of the voltage sag source, so that the confidence coefficient of a positioning result is improved.
Description
Technical Field
The invention belongs to the field of power systems, and particularly relates to a voltage sag source positioning method.
Background
With the application of power electronic equipment in a power grid and the investment of sensitive equipment, the problem of power quality is increasingly receiving wide attention. The voltage sag is one of important power quality problems, and the positioning of the voltage sag has the significance of defining the responsibility of accident parties, reducing economic loss and solving disputes. However, the load model adopted by most of the existing methods in the positioning of the voltage sag source is relatively simple, and the situation that the load contains the source is not considered. When a fault actually occurs, the load source affects the system characteristics, and therefore, it is necessary to separately study the fault. The method for positioning the voltage sag source containing the load source comprises the steps of enabling an upstream system and a downstream system to be equivalent to a series connection of a voltage source and impedance by considering load characteristics, and analyzing the change condition of the voltage at a monitoring point when upstream and downstream parameters change. And an upstream and downstream weight coefficient is defined from the aspect of weight, the proportion relation of voltage sag caused by upstream and downstream is quantitatively analyzed, and the confidence coefficient of a positioning result is improved.
Disclosure of Invention
The technical scheme of the invention is a method for positioning a voltage sag source with a load containing a source. The method is characterized in that: and identifying the source-containing parameters of the upstream and downstream by using a multipoint method based on Thevenin theorem, obtaining a voltage sensitivity equation of the upstream and downstream parameters at the monitoring point, and introducing a weight idea to perform quantitative analysis on the upstream and downstream positioning of the voltage sag source. The upstream and downstream positional relationship of the voltage sag source is shown in fig. 1.
A method for positioning a voltage sag source with a load containing a source comprises the following steps:
step 1: the system is equivalent through Thevenin theorem, a voltage equation at a monitoring point is listed, and the source-containing parameters of the upstream and the downstream are identified by utilizing a multi-point method pseudo-inverse mode
Assuming that the system is a source load, the power system may be equivalent to a Wien model at the monitoring point, the system equivalent model being shown in FIG. 2. The parameters of the upstream and downstream system can be obtained at the monitoring point and are respectively expressed by the formulas (1) and (2):
where the indices x, y denote the real and imaginary parts, respectively, EsAs a system power supply, Rs、XsAs resistance and reactance of the system, ELIs a downstream containing source, RL、XLFor the downstream resistance and reactance, I (1, …, n) represents the nth set of sampled values of the current at the monitoring point, U (1, …, n) represents the nth set of sampled values of the voltage at the monitoring point, and the symbol "+" represents the pseudo-inverse.
Step 2: voltage sensitivity equation for obtaining upstream and downstream parameters at monitoring point
Defining the amount of voltage change caused by the upstream parameter as
The amount of voltage change caused by the downstream parameter is
Represented by formulas (3) and (4), respectively:
wherein the content of the first and second substances,
voltage variation caused by upstream and downstream parameters respectively;
respectively the system voltage before and during the voltage sag; zs-pre、Zs-sagRespectively the system impedance before and during the voltage sag;
respectively before and during voltage sag; zL-pre、ZL-sagThe load impedances before and during a voltage sag are respectively.
And step 3: defining an upstream and downstream weight coefficient from the aspect of weight, and quantitatively analyzing the proportion relation of voltage sag caused by upstream and downstream
The voltage sag weights up and down caused by upstream and downstream faults are respectively defined and expressed by equations (10) and (11):
wherein, up is an upstream weight coefficient and represents an upstream parameter Es、ZsThe relative voltage variation before and after the voltage sag caused by the change; down is a downstream weight coefficient and represents a downstream parameter EL、ZLThe relative change of the voltage before and after the voltage sag caused by the change.
Drawings
FIG. 1 illustrates the upstream and downstream positional relationships of a voltage sag source;
FIG. 2 is a system Thevenin equivalent model;
FIG. 3 is a graph of voltage and current waveforms for the embodiment;
Detailed Description
The preferred embodiments will be described in detail below with reference to the following description. It should be emphasized that the following description is merely exemplary in nature and is not intended to limit the scope of the invention or its application.
The invention provides a method for positioning a voltage sag source with a load containing a source, which comprises the following steps of: the total length of the power transmission line is 200km, and the distance between the monitoring device M and a load power supply is 4 km. Setting a three-phase short-circuit fault point at the upstream of the system, wherein the fault distance is 120km from a system power supply; the failure time is 0.5-1 s; the fault resistance is 1 omega. The method is concretely realized as follows:
1. sampling monitoring data, and dynamically identifying system parameters
Extracting voltage and current waveforms before and during the fault within 0-1s, taking 128 points per half cycle, and taking all data into equations (1) and (2), wherein the system parameters during the upstream and downstream three-phase short-circuit faults are respectively obtained as follows: es-pre＝-0.6631+0.4747i， Es-sag＝-3.2420×10-7-1.1569×10-4i，Zs-pre＝3.1109×10-6+2.0847×10-6i，Zs-sag＝8.5685×10-6-1.0957×10-5i， EL-pre＝-0.6655+0.4717i，EL-sag＝2.0044×10-5-1.1802×10-4i，ZL-pre＝-2.1553×10-5-3.3271×10-6i， ZL-sag＝1.2929×10-5+9.02041×10-6i。
2. Voltage sensitivity equation for obtaining upstream and downstream parameters at monitoring point
Substituting the parameters into voltage sensitivity equations (3) and (4) of upstream and downstream parameters at the monitoring point to obtain
3. Calculating upstream and downstream weights to locate voltage sag sources
Calculating the upstream and downstream weights according to the equations (5) and (6), obtaining the upstream fault time up which is approximately equal to 0.8536 and down which is approximately equal to 0.1464, and judging that the voltage sag source is located at the upstream. The judgment result is consistent with the set fault position, and the correctness of the method provided by the invention is verified.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (3)
1. A method for positioning a voltage sag source with a load containing a source is characterized by comprising the following three steps:
step 1: the system is equivalent through Thevenin theorem, a voltage equation at a monitoring point is listed, and source-containing parameters of the upstream and the downstream are identified by a multi-point method pseudo-inverse solving mode;
step 2: obtaining a voltage sensitivity equation of upstream and downstream parameters at a monitoring point;
and step 3: and defining an upstream and downstream weight coefficient from the aspect of weight, and quantitatively analyzing the proportion relation of voltage sag caused by upstream and downstream.
2. A method for locating the voltage sag source of a load containing a source as claimed in claim 1, wherein the voltage sensitivity equation of the parameters at the upstream and downstream of the monitoring point is obtained in step 2
Represented by formulas (2) and (3), respectively:
wherein the content of the first and second substances,
voltage variation caused by upstream and downstream parameters respectively;
respectively the system voltage before and during the voltage sag; zs-pre、Zs-sagRespectively the system impedance before and during the voltage sag;
the system comprises sources before voltage sag and during voltage sag respectively; zL-pre、ZL-sagThe load impedances before and during a voltage sag are respectively.
3. A method for positioning voltage sag sources containing sources in loads according to claim 2 is characterized in that in step 3, voltage sag weights up and down caused by upstream and downstream faults are respectively defined as expressed in formulas (3) and (4):
wherein, up is an upstream weight coefficient and represents an upstream parameter Es、ZsThe relative voltage variation before and after the voltage sag caused by the change; down is a downstream weight coefficient and represents a downstream parameter EL、ZLThe relative change of the voltage before and after the voltage sag caused by the change.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010715193.4A CN112130024A (en) | 2020-07-22 | 2020-07-22 | Voltage sag source positioning method for load containing source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010715193.4A CN112130024A (en) | 2020-07-22 | 2020-07-22 | Voltage sag source positioning method for load containing source |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112130024A true CN112130024A (en) | 2020-12-25 |
Family
ID=73851371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010715193.4A Pending CN112130024A (en) | 2020-07-22 | 2020-07-22 | Voltage sag source positioning method for load containing source |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112130024A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104215882A (en) * | 2014-09-09 | 2014-12-17 | 中国矿业大学 | Voltage sag source locating method based on active single-port network resistor polarity |
| CN104360235A (en) * | 2014-11-19 | 2015-02-18 | 南京工程学院 | Method for positioning voltage sag source of complex power distribution network including DGs |
| CN106154109A (en) * | 2016-06-21 | 2016-11-23 | 南瑞（武汉）电气设备与工程能效测评中心 | A kind of voltage sag source localization method considering divisions of responsibility |
-
2020
- 2020-07-22 CN CN202010715193.4A patent/CN112130024A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104215882A (en) * | 2014-09-09 | 2014-12-17 | 中国矿业大学 | Voltage sag source locating method based on active single-port network resistor polarity |
| CN104360235A (en) * | 2014-11-19 | 2015-02-18 | 南京工程学院 | Method for positioning voltage sag source of complex power distribution network including DGs |
| CN106154109A (en) * | 2016-06-21 | 2016-11-23 | 南瑞（武汉）电气设备与工程能效测评中心 | A kind of voltage sag source localization method considering divisions of responsibility |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Livani et al. | A machine learning and wavelet-based fault location method for hybrid transmission lines | |
| CN101907437B (en) | Wavelet difference algorithm-based cable fault localization method | |
| EP3043186B1 (en) | Method and system for identifying full parameters of element by fault recorder, and fault locating method | |
| Dashti et al. | Accuracy improvement of impedance‐based fault location method for power distribution network using distributed‐parameter line model | |
| CN107329040A (en) | A kind of power distribution automation main station system single-phase earth fault localization method based on transient state recorder data | |
| CN103018632B (en) | Small current grounding system single-phase ground fault line selection method based on fisher information | |
| CN109444657B (en) | Method for positioning high-resistance grounding fault section of power distribution network | |
| CN104297628B (en) | The section fault detection of the power distribution network containing DG and localization method | |
| CN114384374A (en) | Fault study and judgment method and device based on edge calculation FTU and fault indicator | |
| CN113671314B (en) | Method for positioning and ranging single-phase earth fault section of ring network of power distribution network | |
| CN108845225B (en) | Method for analyzing wiring correctness of secondary current loop of power capacitor and reactor | |
| CN104374988A (en) | Voltage sag sorting method considering phase jumps | |
| CN108535597B (en) | Line model-based single-phase earth fault section positioning method | |
| CN110108971B (en) | Arc detection method for tree grounding fault of overhead bare conductor | |
| Dalcastagne et al. | A study about the sources of error of impedance-based fault location methods | |
| Das et al. | Estimating zero-sequence impedance of three-terminal transmission line and Thevenin impedance using relay measurement data | |
| CN110261723B (en) | Low-current grounding line selection method based on coefficient of variation and high-order cumulant | |
| CN114441891A (en) | Power distribution network single-phase earth fault line selection method based on current signal similarity | |
| CN112130024A (en) | Voltage sag source positioning method for load containing source | |
| CN106646138A (en) | Method for locating grounding fault of power distribution network based on multi-sample frequency wavelet character energy conversion | |
| CN109103857B (en) | Method and device for monitoring synchronous state of pilot channel for line protection | |
| CN110645887A (en) | Winding deformation judgment method based on short-circuit reactance | |
| CN113985210B (en) | Voltage sag domain calculation method considering voltage sag amplitude and duration | |
| CN112415326B (en) | Power distribution network fault section identification method based on fuzzy clustering algorithm | |
| Shu et al. | Fault phase selection and distance location based on ANN and S-transform for transmission line in triangle network |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |