CN105699782B - The test method of the mutual impedance of transmission lines in parallel - Google Patents
The test method of the mutual impedance of transmission lines in parallel Download PDFInfo
- Publication number
- CN105699782B CN105699782B CN201610099383.1A CN201610099383A CN105699782B CN 105699782 B CN105699782 B CN 105699782B CN 201610099383 A CN201610099383 A CN 201610099383A CN 105699782 B CN105699782 B CN 105699782B
- Authority
- CN
- China
- Prior art keywords
- phase
- test
- line
- voltage
- frequency component
- 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
- 230000005540 biological transmission Effects 0.000 title claims abstract description 56
- 238000010998 test method Methods 0.000 title claims abstract description 12
- 238000012360 testing method Methods 0.000 claims abstract description 166
- 238000000034 method Methods 0.000 claims description 21
- 238000001514 detection method Methods 0.000 abstract description 4
- 238000005259 measurement Methods 0.000 abstract 5
- 230000008878 coupling Effects 0.000 description 36
- 238000010168 coupling process Methods 0.000 description 36
- 238000005859 coupling reaction Methods 0.000 description 36
- 238000005070 sampling Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 2
- 230000032683 aging Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000016507 interphase Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/08—Measuring resistance by measuring both voltage and current
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2605—Measuring capacitance
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The present invention relates to a kind of test methods of the mutual impedance of transmission lines in parallel.The test method of the mutual impedance includes the following steps：The head end of a phase measurement circuit in measurement circuit is accessed into alien frequencies test voltage, the end ground connection of the phase measurement circuit；The head end voltage, head end electric current, end current of the phase measurement circuit are tested, and calculates voltage power frequency component and electric current alien frequencies component；Head end voltage, the head end electric current of a phase working line in test run circuit, and calculate voltage alien frequencies component and electric current power frequency component；The mutual impedance between the phase measurement circuit and the phase working line is calculated according to the electric current alien frequencies component and voltage alien frequencies component.The test method of the present invention under the conditions of working line " does not have a power failure " can accurately test the mutual impedance of transmission lines in parallel, improves detection efficiency and accuracy.
Description
The invention is a divisional application of the invention entitled "testing method of mutual impedance and coupling capacitance of parallel transmission line" on application date 20110201 and application number 201110034423.1.
Technical Field
The invention relates to a pilot frequency incremental method for coupling parameters of parallel transmission lines, in particular to a method for testing mutual impedance and coupling capacitance of the parallel transmission lines.
Background
The transmission line is an important component of the power system, and the line parameters of the transmission line need to be measured at the initial stage of line construction. Although these parameters will not change for a considerable period of time, the line parameters may change due to aging of the wires after long-term operation, changes in soil resistivity, or influences of weather, environment, geography and other factors. Therefore, the power dispatching department requires actually measuring the power frequency parameters of the transmission line. The power frequency parameters generally comprise direct current resistance, positive sequence impedance, interphase capacitance, positive sequence capacitance, zero sequence capacitance, and mutual impedance and coupling capacitance among multiple parallel transmission lines.
However, the parameter test of the parallel transmission lines, especially the coupling parameter test among multiple loops of parallel transmission lines, involves extremely wide power failure range and has strong interference, and the parameter test is almost impossible to implement in practical test. The accuracy of the parameters is crucial to the safe operation of the power grid, and therefore, a method capable of accurately testing the coupling parameters of the line under the condition that the relevant line is not powered off is needed.
Disclosure of Invention
The invention aims to provide a method for accurately testing the mutual impedance of parallel transmission lines under the condition that related lines are not powered off.
Another objective of the present invention is to provide a method for accurately testing the coupling capacitance of parallel transmission lines under the condition of no power outage of the relevant lines.
A mutual impedance test method of parallel transmission lines comprises a test line and an operation line, and comprises the following steps: connecting the head end of one phase of test circuit in the test circuits to pilot frequency test voltage, and grounding the tail end of the phase of test circuit; testing the head end voltage, the head end current and the tail end current of the phase test circuit, and calculating a voltage power frequency component and a current pilot frequency component; testing the head end voltage and head end current of one phase of the operation line, and calculating a voltage pilot frequency component and a current power frequency component; and calculating the mutual impedance between the phase test line and the phase operation line according to the current pilot frequency component and the voltage pilot frequency component.
In an embodiment of the present invention, the parallel transmission lines are double-circuit lines, and the mutual impedance between the phase test line and the phase operation line is equal to or greater than a predetermined valueWherein,is the power frequency component of the voltage,for the said current pilot frequency component, the frequency of the pilot frequency component,for the said voltage inter-frequency component,is the current power frequency component.
In an embodiment of the present invention, the parallel transmission line is a multi-circuit line, and the mutual impedance between the phase test line and the phase operation line is a multiple-circuit lineWherein,for the said voltage inter-frequency component,is the current pilot frequency component.
In a preferable technical solution of the transimpedance testing method, the frequency range of the pilot frequency test voltage is 47.5Hz to 52.5 Hz.
In a preferred technical solution of the mutual impedance testing method, the number of times of testing the mutual impedance between the phase testing line and the phase running line by using the testing method is not less than 10 times.
A method for testing coupling capacitance of parallel transmission lines comprises a test line and an operation line, and comprises the following steps: connecting the head end of one phase of test circuit in the test circuits to pilot frequency test voltage, and opening the tail end of the phase of test circuit; testing the head end voltage, head end current, tail end current and frequency of the phase test circuit, and calculating a voltage power frequency component and a current power frequency component; testing the head end voltage, head end current and frequency of one phase of the operation lines, and calculating voltage pilot frequency components and current pilot frequency components; and calculating the coupling capacitance between the phase test line and the phase operation line according to the current pilot frequency component and the voltage pilot frequency component.
In an embodiment of the above-described coupling capacitance testing method, the parallel transmission lines are double-circuit lines, and the coupling capacitance between the phase testing line and the phase operating line is equal to or greater than a predetermined valueWherein,is a power frequency component of the voltage,is a current power frequency component, f1In order to be the pilot frequency,in order to be a voltage pilot frequency component,is a current pilot frequency component, f2Is the power frequency.
In an embodiment of the above-described coupling capacitance testing method, the parallel transmission line is a multi-circuit line, and the coupling capacitance between the phase test line and the phase operating line is a coupling capacitance between the phase test line and the phase operating lineWherein,in order to be a voltage pilot frequency component,is a current pilot frequency component, f2Is the power frequency.
In an optimized technical scheme of the coupling capacitance testing method, the sampling frequency of the testing method is fsThen, thenWherein f is1Is the pilot frequency, f2The power frequency is N, and the sampling length is N.
In a preferable technical scheme of the coupling capacitance testing method, the frequency range of the pilot frequency test voltage is 47.5Hz to 52.5 Hz.
The method for testing the mutual impedance and the coupling capacitance of the parallel transmission line can accurately test the mutual impedance and the coupling capacitance of the parallel transmission line under the condition that the running line is not powered off, and improves the detection efficiency and the detection accuracy.
Drawings
Fig. 1 is a schematic diagram of the testing principle of the mutual impedance of the parallel transmission lines of the present invention.
Fig. 2 is a flow chart of a testing method of the mutual impedance of the parallel transmission lines of the present invention.
Fig. 3 is a schematic diagram of the testing principle of the coupling capacitance of the parallel transmission line of the present invention.
Fig. 4 is a flowchart of a method for testing the coupling capacitance of the parallel transmission lines according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below by taking a double-circuit power transmission line as an example.
In the testing method, the parallel double-circuit power transmission line comprises a testing line and an operating line, wherein the testing line comprises an A-phase testing line, a B-phase testing line and a C-phase testing line, and the operating line comprises an A-phase operating line, a B-phase operating line and a C-phase operating line. The A-phase test circuit corresponds to the A-phase operation circuit, the B-phase test circuit corresponds to the B-phase operation circuit, and the C-phase test circuit corresponds to the C-phase operation circuit.
The following describes the method for testing the mutual impedance of parallel transmission lines in detail, taking the example of testing the mutual impedance between a B-phase test line and a B-phase operating line in a double-circuit transmission line. Referring to fig. 1, fig. 1 is a schematic diagram illustrating a testing principle of mutual impedance of parallel transmission lines according to the present invention. The head end of the B-phase test circuit is connected with pilot frequency test voltage Us, and the tail end of the B-phase test circuit is grounded. Preferably, the frequency range of the pilot frequency test voltage is 47.5Hz to 52.5 Hz. The head end measuring device 11 is connected with the head end of the B-phase test circuit through a first voltage transformer 13 and a first current transformer 14, and is used for testing the head end voltage and the head end current of the B-phase test circuit. The head end measuring device 11 is further connected to the head end of the B-phase operating line through a second voltage transformer 15 and a second current transformer 16, and is used for testing the head end voltage and the head end current of the B-phase operating line. The end measuring device 12 is connected to the end of the B-phase operating line through a third current transformer 17, and is used for testing the end current of the B-phase operating line.
Referring to fig. 2, fig. 2 is a flowchart of a testing method of mutual impedance of parallel transmission lines according to the present invention. The invention relates to a method for testing mutual impedance of parallel transmission lines, which comprises the following steps:
and connecting the head end of the B-phase test circuit to pilot frequency test voltage, and grounding the tail end of the B-phase test circuit. Preferably, the frequency range of the pilot frequency test voltage is 47.5Hz to 52.5 Hz.
Measuring the head end voltage, head end current and tail end current of the B-phase test circuit, and calculating the power frequency component of the voltageWith current pilot frequency component
Measuring the head end voltage and head end current of the B-phase operating line, and calculating the voltage pilot frequency componentWith current power frequency componentPreferably, the head end and the tail end of the phase B test line and the phase B operation line are synchronously tested and recorded.
And (3) calculating the mutual impedance between the B-phase test line and the B-phase operation line according to the formula (1), and further converting to 50 Hz.
According to the test method, the mutual impedance between the A-phase test circuit and the A-phase operation circuit, the A-phase test circuit and the B-phase operation circuit, the A-phase test circuit and the C-phase operation circuit, the B-phase test circuit and the A-phase operation circuit, the B-phase test circuit and the C-phase operation circuit, the C-phase test circuit and the A-phase operation circuit, the C-phase test circuit and the B-phase operation circuit, and the C-phase test circuit and the C-phase operation circuit can be respectively tested by pressurizing and testing the corresponding test circuit changes.
The method for testing the mutual impedance of the parallel transmission lines is also suitable for the parallel multi-circuit transmission lines. When testing the mutual impedance among a plurality of power transmission lines, the testing method is used for testing according to the parallel combination. For parallel multi-circuit transmission lines, in order to further improve the accuracy of the test result, the mutual impedance between the test line and the corresponding operation line
Wherein,in order to operate the voltage pilot frequency component of the line,to test the current pilot frequency component of the line.
Preferably, in the method for testing the mutual impedance of the parallel transmission lines, the testing times of the mutual impedance between each phase of the test line and the corresponding operating line are not less than 10, and an optimal value or an average value is selected from the testing times. Preferably, in the testing method of the present invention, a digital filter is selected. Sampling frequency f in the test method of the inventionsThe sampling time is selected to satisfy the requirement of the formula (3),
wherein f is1Is the pilot frequency, f2The power frequency is N, and the sampling length is N.
The following describes the method for testing the coupling capacitance of the parallel transmission line in detail, taking the example of testing the coupling capacitance between the B-phase test line and the B-phase operating line in the double-circuit transmission line. Referring to fig. 3, fig. 3 is a schematic diagram illustrating a testing principle of a coupling capacitor of a parallel transmission line according to the present invention. The head end of the B-phase test circuit is connected with pilot frequency test voltage Us, and the tail end of the B-phase test circuit is open-circuited. Preferably, the frequency range of the pilot frequency test voltage is 47.5Hz to 52.5 Hz. The head end measuring device 21 is connected with the head end of the B-phase test circuit through a first voltage transformer 23 and a first current transformer 24, and is used for testing the head end voltage and the head end current of the B-phase test circuit. The head end measuring device 21 is further connected to the head end of the B-phase operating line through a second voltage transformer 25 and a second current transformer 26, and is used for testing the head end voltage and the head end current of the B-phase operating line. The end measuring device 22 is connected to the end of the B-phase operating line through a third current transformer 27 for testing the end current of the B-phase operating line.
Referring to fig. 4, fig. 4 is a flowchart of a method for testing a coupling capacitance of a parallel transmission line according to the present invention. The method for testing the coupling capacitance of the parallel transmission line comprises the following steps:
and connecting the head end of the B-phase test circuit to pilot frequency test voltage, and opening the tail end of the B-phase test circuit. Preferably, the frequency range of the pilot frequency test voltage is 47.5Hz to 52.5 Hz.
Measuring the head end voltage, head end current and tail end current of the B-phase test circuit, and calculating the power frequency component of the voltageWith current power frequency component
Measuring the head end voltage and head end current of the B-phase operating line, and calculating the voltage pilot frequency componentWith current pilot frequency componentPreferably, the head end and the tail end of the phase B test line and the phase B operation line are synchronously tested and recorded.
And calculating the coupling capacitance between the B-phase test line and the B-phase running line according to a formula (4) and further converting the coupling capacitance to 50 Hz.
According to the test method, the coupling capacitance between the A-phase test circuit and the A-phase operation circuit, the A-phase test circuit and the B-phase operation circuit, the A-phase test circuit and the C-phase operation circuit, the B-phase test circuit and the A-phase operation circuit, the B-phase test circuit and the C-phase operation circuit, the C-phase test circuit and the A-phase operation circuit, the C-phase test circuit and the B-phase operation circuit, and the C-phase test circuit and the C-phase operation circuit can be respectively tested by pressurizing and testing the corresponding test circuit changes.
The method for testing the coupling capacitance of the parallel power transmission line is also suitable for the parallel multi-circuit power transmission line. When the coupling capacitance among the multi-circuit transmission lines is tested, the testing method is used for testing according to the parallel combination. For parallel multi-circuit transmission lines, in order to further improve the accuracy of the test result, the coupling capacitors between the test lines and the corresponding operating lines
Wherein,in order to operate the voltage pilot frequency component of the line,is the current pilot frequency component of the operating line.
Preferably, in the method for testing the coupling capacitance of the parallel transmission line of the present invention, the number of times of testing the coupling capacitance between each phase of the test line and the corresponding operating line is not less than 10, and an optimal value or an average value is selected from the number of times of testing the coupling capacitance between each phase of the test line and the corresponding operating line. Preferably, in the testing method of the present invention, a digital filter is selected. Sampling frequency f in the test method of the inventionsThe sampling time is selected to satisfy the requirement of the formula (6),
wherein f is1Is the pilot frequency, f2The power frequency is N, and the sampling length is N.
Compared with the prior art, the method for testing the mutual impedance and the coupling capacitance of the parallel transmission line can accurately test the mutual impedance and the coupling capacitance of the parallel transmission line under the condition that the running line is not powered off, and improves the detection efficiency and accuracy.
Many widely different embodiments may be made of the invention without departing from the spirit and scope thereof. It should be understood that the invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.
Claims (3)
1. A mutual impedance test method of parallel transmission lines is characterized in that the parallel transmission lines comprise test lines and operation lines, and the mutual impedance test method of the parallel transmission lines comprises the following steps:
connecting the head end of one phase of test circuit in the test circuits to pilot frequency test voltage, and grounding the tail end of the phase of test circuit;
testing the head end voltage, the head end current and the tail end current of the phase test circuit, and calculating a voltage power frequency component and a current pilot frequency component;
testing the head end voltage and head end current of one phase of the operation line, and calculating a voltage pilot frequency component and a current power frequency component;
calculating the mutual impedance between the phase test line and the phase operation line according to the current pilot frequency component and the voltage pilot frequency component;
wherein, when the parallel transmission line is a double-circuit line, the mutual impedance between the phase test line and the phase operation lineWherein,is the power frequency component of the voltage,for the said current pilot frequency component, the frequency of the pilot frequency component,for the said voltage inter-frequency component,is the current power frequency component;
when the parallel transmission line is a multi-circuit line, the mutual impedance between the phase test line and the phase operation lineWherein,for the said voltage inter-frequency component,is the current pilot frequency component.
2. The method of claim 1, wherein the pilot frequency test voltage has a frequency range of 47.5Hz to 52.5 Hz.
3. The method of claim 1, wherein the number of times the mutual impedance between the phase test line and the phase operational line is tested using the test method is not less than 10 times.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610099383.1A CN105699782B (en) | 2011-02-01 | 2011-02-01 | The test method of the mutual impedance of transmission lines in parallel |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610099383.1A CN105699782B (en) | 2011-02-01 | 2011-02-01 | The test method of the mutual impedance of transmission lines in parallel |
| CN201110034423.1A CN102621389B (en) | 2011-02-01 | 2011-02-01 | The method of testing of the coupling capacitance of transmission lines in parallel |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110034423.1A Division CN102621389B (en) | 2011-02-01 | 2011-02-01 | The method of testing of the coupling capacitance of transmission lines in parallel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105699782A CN105699782A (en) | 2016-06-22 |
| CN105699782B true CN105699782B (en) | 2018-05-25 |
Family
ID=46561421
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110034423.1A Active CN102621389B (en) | 2011-02-01 | 2011-02-01 | The method of testing of the coupling capacitance of transmission lines in parallel |
| CN201610099383.1A Active CN105699782B (en) | 2011-02-01 | 2011-02-01 | The test method of the mutual impedance of transmission lines in parallel |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110034423.1A Active CN102621389B (en) | 2011-02-01 | 2011-02-01 | The method of testing of the coupling capacitance of transmission lines in parallel |
Country Status (1)
| Country | Link |
|---|---|
| CN (2) | CN102621389B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104820133A (en) * | 2015-04-14 | 2015-08-05 | 广东电网有限责任公司电力科学研究院 | Online measurement method for impedance parameter of three-phase asymmetric power transmission line |
| CN108181513B (en) * | 2018-03-15 | 2020-02-04 | 广东电网有限责任公司惠州供电局 | Inter-phase coupling capacitance testing method and system for lightning arrester based on pilot frequency method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101034117A (en) * | 2007-04-02 | 2007-09-12 | 武汉大学 | Power transmission line power frequency parameters measuring method and device |
| CN101424715A (en) * | 2008-12-05 | 2009-05-06 | 河南电力试验研究院 | Power frequency parameter measuring set for high-pressure power transmission line |
| CN101696993A (en) * | 2009-10-23 | 2010-04-21 | 武汉大学 | Method for electrically measuring zero sequence impedance parameter by mutual induction line of pilot frequency injection current |
| CN101706533A (en) * | 2009-11-10 | 2010-05-12 | 武汉大学 | Method for measuring zero sequence impedance parameters of transmission lines by utilizing current of line ends |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4148087A (en) * | 1977-04-20 | 1979-04-03 | Phadke Arun G | Distance relay for electric power transmission lines |
| JPH0718906B2 (en) * | 1985-10-25 | 1995-03-06 | 東京電力株式会社 | Fault locator for power transmission system |
| CN101419253B (en) * | 2008-12-17 | 2011-02-16 | 河南电力试验研究院 | Uhv transmission line positive sequence and zero sequence parameter measurement method and system |
| JP2010160000A (en) * | 2009-01-06 | 2010-07-22 | Renesas Electronics Corp | Impedance measuring method |
-
2011
- 2011-02-01 CN CN201110034423.1A patent/CN102621389B/en active Active
- 2011-02-01 CN CN201610099383.1A patent/CN105699782B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101034117A (en) * | 2007-04-02 | 2007-09-12 | 武汉大学 | Power transmission line power frequency parameters measuring method and device |
| CN101424715A (en) * | 2008-12-05 | 2009-05-06 | 河南电力试验研究院 | Power frequency parameter measuring set for high-pressure power transmission line |
| CN101696993A (en) * | 2009-10-23 | 2010-04-21 | 武汉大学 | Method for electrically measuring zero sequence impedance parameter by mutual induction line of pilot frequency injection current |
| CN101706533A (en) * | 2009-11-10 | 2010-05-12 | 武汉大学 | Method for measuring zero sequence impedance parameters of transmission lines by utilizing current of line ends |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102621389B (en) | 2016-04-20 |
| CN102621389A (en) | 2012-08-01 |
| CN105699782A (en) | 2016-06-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108181547B (en) | Dynamic time bending distance fault section positioning method based on time sequence compression | |
| CN106443307B (en) | Transformer equipment insulated on-line monitoring system | |
| CN205103389U (en) | High frequency partial discharge detector verification system | |
| CN104865549A (en) | Reliability evaluation method and system of electric energy metering device | |
| CN102981110A (en) | Data measurement and storage system and method for achieving high frequency and ultra-high frequency partial discharge monitoring of transformer | |
| CN100410671C (en) | Method for on-line monitoring insulating hidden danger of double-pipe for transformer | |
| CN105699782B (en) | The test method of the mutual impedance of transmission lines in parallel | |
| CN107765084B (en) | Universal voltage input power frequency signal frequency measurement system | |
| CN103424627A (en) | Method for measuring zero-sequence impedance of parallel distribution network circuit at double ends | |
| Frey et al. | Study of high frequency harmonics propagation in industrial networks | |
| CN104459330A (en) | High-voltage transmission line zero-sequence impedance measuring circuit and method | |
| CN108181513B (en) | Inter-phase coupling capacitance testing method and system for lightning arrester based on pilot frequency method | |
| CN110645887A (en) | Winding deformation judgment method based on short-circuit reactance | |
| CN105785246A (en) | Live-line detecting and on-line monitoring device used for ultrahigh-voltage power cable insulation diagnosis | |
| CN203224571U (en) | A flexible grounding resistance tester | |
| CN205691705U (en) | A kind of ground fault detection device based on capacitance partial pressure | |
| CN105203886A (en) | Capacitive type current transformer online detection device and method | |
| CN104360299A (en) | On-site wireless inspection device and method for capacitive type device on-line monitoring system | |
| CN204287327U (en) | A kind of ultra-high-tension power transmission line zero sequence impedance metering circuit | |
| CN103698675B (en) | Analysis method and system for partial discharge under oscillation type impulse voltage | |
| CN202649309U (en) | Direct current resistance test system of power transmission line | |
| CN202281833U (en) | Capacitance type high-voltage current transformer medium loss angle tangent value on-line monitor | |
| CN202330523U (en) | Capacitive sampling voltage box for voltage quality monitoring of 220kV power system | |
| CN206584034U (en) | A kind of electronic type voltage transformer disconnecting switch division test device | |
| CN206223872U (en) | Condenser type electric power equipment dielectric loss on-line detecting system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C41 | Transfer of patent application or patent right or utility model | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20160613 Address after: 200002 Nanjing East Road, Shanghai, No. 181, No. Applicant after: State Grid Shanghai Municipal Electric Power Company Applicant after: East China Electric Power Test & Research Institute Co., Ltd. Address before: 200437 Handan Road, Shanghai, No. 171, No. Applicant before: East China Electric Power Test & Research Institute Co., Ltd. |
|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |