CN204855773U - Self -correcting coil of CT measurement winding for electric power system - Google Patents
Self -correcting coil of CT measurement winding for electric power system Download PDFInfo
- Publication number
- CN204855773U CN204855773U CN201520554853.XU CN201520554853U CN204855773U CN 204855773 U CN204855773 U CN 204855773U CN 201520554853 U CN201520554853 U CN 201520554853U CN 204855773 U CN204855773 U CN 204855773U
- Authority
- CN
- China
- Prior art keywords
- winding
- self
- button
- current transformer
- power system
- 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
- 238000004804 winding Methods 0.000 title claims abstract description 134
- 238000005259 measurement Methods 0.000 title abstract description 14
- 238000009413 insulation Methods 0.000 claims description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 10
- 238000001514 detection method Methods 0.000 claims description 6
- 238000000034 method Methods 0.000 description 20
- 238000012360 testing method Methods 0.000 description 12
- 230000008569 process Effects 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000004907 flux Effects 0.000 description 3
- 238000012423 maintenance Methods 0.000 description 3
- 230000001052 transient effect Effects 0.000 description 3
- 238000009434 installation Methods 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
Landscapes
- Transformers For Measuring Instruments (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
The utility model provides a self -correcting coil of CT measurement winding for electric power system, including draw -in groove switch, primary winding and secondary winding, secondary winding includes the same first winding of ampere turn and secondary winding, the both ends of first winding and secondary winding all are provided with connecting terminal, connecting terminal's middle part all is equipped with a fretwork recess, when the normal during operation of current transformer, first winding and secondary winding pass through draw -in groove switch parallel connection, carry out the self -correcting as current transformer and examine time measuring, first winding and secondary winding disconnect. Compared with the prior art, the utility model provides a pair of self -correcting coil of CT measurement winding for electric power system carries out the error when measuring to the current transformer coil, need not use large -scale liter to flow ware, the long lead that bears the kiloampere and precision standard ware, greatly reduced at the error surveying work of job site to current transformer, simplified the measurement mode of connection, improved work efficiency.
Description
Technical Field
The utility model relates to a power grid operation maintenance field, concretely relates to CT measures coil of autoverification of winding for electric power system.
Background
The metering winding of a Current Transformer (CT) for an electric power system needs to be periodically tested according to the regulations of the metering method. The periodic detection of the CT error characteristics is an important basis for accurately evaluating the economic operation of the power grid. Along with the improvement of voltage level, GIS pipeline diameter and return circuit length all can increase, also can increase to the degree of difficulty of carrying out error characteristic test to the CT coil of installing on its surface. In current power grid engineering, error testing is mainly performed before installation of a CT coil, and in most cases, an equal ampere-turn method is adopted, namely, a primary conductor is wound on the CT coil, or a primary lead is wound on a tank body provided with the CT coil with the length of several meters. However, this test method does not actually perform a cross-over test of error characteristics for CT. If a comparison method is used for CT error characteristic test after CT installation, a closed large-current test loop is formed by connecting equipment such as a standard CT and a high-power current booster outside two outgoing line sleeves of a GIS. The method is difficult to implement in extra-high voltage engineering, and even with the aid of the grounding disconnecting link, error measurement cannot be carried out under a steady-state large current because the flow of the grounding disconnecting link is only hundreds of amperes. If the method is adopted to carry out error measurement, the equipment such as a circuit breaker, a disconnecting switch and the like is required to carry out design operation according to the high-current loop structure, and the method puts higher requirements on equipment manufacturing units. Meanwhile, because the test loop is extremely long, the capacity requirement of the large-current booster is often greater than that of the large-current booster, so that a test unit has a large burden on equipment investment and manpower investment. With the rapid construction of the extra-high voltage engineering, the number of devices is more and more, the state detection and the state evaluation of the CT are considered, and the operation and maintenance workload is reduced.
The power frequency current proportion tracing technology is applied to power system engineering, on-site self-correction of CT error characteristics for engineering is achieved, operation and maintenance work efficiency is greatly improved, and the requirement for detecting the CT periodic error characteristics is met. The most primitive and extensive method for tracing CT error characteristic magnitude is CT self-calibration, and a power frequency current sensor adopts a method of 1A: the method of 1A is used for carrying out magnitude tracing. If the material, size and ampere-turns of the CT iron core are properly selected, the accuracy level of CT can reach a very high level even if compensation and other measures are not adopted. For example, the current transformer reference (primary current range 0-60kA, accuracy class 2 × 10) stored in the national high-voltage metering station-7-1×10-6) Namely error calibration by adopting a self-correcting mode. At present, laboratories which undertake tracing and transferring of current proportion magnitude in economically developed countries such as Europe, America, Canada and the like adopt a self-correcting means to calibrate the highest accuracy level of the current transformer. Wherein, the current transformer error accuracy grade of NIST of national institute of standards and technology is 1 × 10-5(ii) a The German Federal physical technical institute PTB has an error accuracy rating of 2X 10-6-1×10-5(ii) a The national institute of Canada NRC error accuracy rating of 2X 10-6-1×10-5。
For the work of the CT for measurement, a CT self-calibration method is a mature technology, but is never adopted on the engineering CT, and the main difficulty is that the CT for engineering has a series of operation conditions which are not related to the CT for measurement, such as insulation performance, system short-circuit current tolerance, long-term work heating and the like besides the requirement of error characteristics. In addition, the engineering CT must be simple in operation method and safe and reliable in use. Therefore, it is necessary to provide a self-calibration CT coil design method suitable for extra-high voltage engineering application.
Disclosure of Invention
In order to satisfy prior art's needs, the utility model provides a CT measures coil of autoverification of winding for electric power system.
The technical scheme of the utility model is that:
the self-correcting coil comprises a primary winding and a secondary winding, and the secondary winding comprises a first winding and a second winding which have the same ampere-turns;
the two ends of the first winding are provided with connecting terminals, and the two ends of the second winding are also provided with connecting terminals; the middle parts of the connecting terminals are respectively provided with a hollow groove;
the self-calibration coil further comprises a card slot switch:
when the current transformer works normally, the first winding and the second winding are connected in parallel through the slot switch;
when the current transformer carries out self-calibration detection, the first winding and the second winding are disconnected.
Preferably, the card slot switch comprises an insulated button a1, an insulated button a2, an insulated button b1 and an insulated button b 2; the insulated button a1 is connected with the insulated button b2 through a lead, and the insulated button a2 is also connected with the insulated button b1 through a lead;
each insulating button is provided with a convex point;
preferably, when the first winding and the second winding are connected in parallel through the card slot switch:
the salient point of the insulation button a1 is embedded into the hollow groove of the connecting terminal at one side of the first winding, and the salient point of the insulation button b2 is embedded into the hollow groove of the connecting terminal at the other side of the first winding;
the salient point of the insulation button b1 is embedded into the hollow groove of the connecting terminal at one side of the second winding, and the salient point of the insulation button a2 is embedded into the hollow groove of the connecting terminal at the other side of the second winding;
preferably, the first winding and the second winding are wound on an iron core of the current transformer in a spaced and parallel winding manner;
preferably, a protection box is arranged outside an iron core of the current transformer.
Compared with the closest prior art, the utility model discloses an excellent effect is:
1. the utility model provides a self-calibration coil of CT metering winding for electric power system, when carrying out error measurement to the current transformer coil, need not use large-scale current rising ware, bear the long wire and the accurate etalon of last kilo ampere, greatly reduced the error measurement work to current transformer at the job site, simplified the measurement wiring mode, improved work efficiency;
2. the utility model provides a self-calibration coil of CT metering winding for electric power system, the first winding and the second winding adopt the mode of interval parallel winding, which reduces the leakage reactance between the two secondary windings;
3. the utility model provides a self-calibration coil of CT metering winding for electric power system, which can be applied to the field handover test of current transformer and the device detection of current transformer;
4. the utility model provides a pair of CT measures coil of school from of winding for electric power system, first winding and second winding adopt the draw-in groove switch to connect, have made things convenient for the connection and the change of winding.
Drawings
The present invention will be further explained with reference to the accompanying drawings.
FIG. 1: the embodiment of the utility model provides a design schematic diagram of a self-calibration coil of a CT metering winding for an electric power system;
FIG. 2: the embodiment of the utility model provides an in electric power system with CT measurement winding the front view of the coil of school;
FIG. 3: the embodiment of the utility model provides an embodiment is the top view of the self-calibration coil of CT measurement winding for electric power system;
FIG. 4: the structure schematic diagram of the connecting terminal in the embodiment of the utility model;
FIG. 5: the embodiment of the utility model provides a structural schematic diagram of draw-in groove switch;
wherein, 1: a connection terminal; 2: a protection box for the iron core; 3: a secondary winding; 4: and (3) an iron core.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.
The utility model provides a specific embodiment of a self-calibration coil of a CT metering winding for an electric power system, which is shown in figure 1,
the self-correcting coil comprises a slot switch and a primary winding N1And a secondary winding.
1. Secondary winding
As shown in fig. 1, the secondary winding includes a first winding N2And a second winding N3. Wherein,
first winding N2The two ends of the connecting terminal are provided with a connecting terminal S1 and a connecting terminal S2, as shown in FIG. 4, the middle parts of the connecting terminals are provided with a hollow groove;
second winding N3Also provided with a connecting terminal S3 and a connecting terminal S4, as shown in fig. 4, the middle part of each connecting terminal is provided with a hollowed-out groove.
In the embodiment, the first winding and the second winding are wound on the iron core of the current transformer in an interval and parallel winding mode so as to reduce the additional leakage reactance between the two secondary windings. And a protection box is arranged outside the iron core of the current transformer.
2. A card slot switch:
as shown in fig. 5, the card slot switch includes an insulated button a1, an insulated button a2, an insulated button b1, and an insulated button b 2. Wherein,
the insulated button a1 is connected with the insulated button b2 through a lead, the insulated button a2 is also connected with the insulated button b1 through a lead, and the insulated button a1 and the insulated button b1 are used as a switch K in a card slot switch1Insulating button a2 and insulating button b2 as a switch K in a card slot switch2At both ends of the same. And each insulating button is provided with a bump.
(1) When current transformer normal operating, first winding and second winding pass through draw-in groove switch parallel connection, specifically do:
the salient point of the insulation button a1 is embedded into the hollow groove of the connecting terminal at one side of the first winding, and the salient point of the insulation button b2 is embedded into the hollow groove of the connecting terminal at the other side of the first winding; the salient point of the insulation button b1 is embedded into the hollow groove of the connecting terminal at one side of the second winding, and the salient point of the insulation button a2 is embedded into the hollow groove of the connecting terminal at the other side of the second winding.
I.e. as shown in fig. 4 and 5, switch K1Are respectively embedded into the connection terminals S1 and S3, switch K2Are respectively embedded in the connection terminals S2 and S4.
(2) When the current transformer carries out self-calibration detection, the first winding and the second winding are disconnected, and the specific working process is as follows:
first winding N in the present embodiment2And a second winding N3The ampere turns are the same.
The method comprises the following steps: measuring error data e of first winding when current transformer normally works11And error data e of the second winding21In the present embodiment, the error data is measured by a comparison method, and a current may be passed through the error dataAnd obtaining a delivery test and a handover test of the mutual inductor.
Secondly, the step of: a first winding N2As a new primary winding, a secondary winding N3As a secondary winding, a self-calibration module is formed, i.e. the switch K shown in FIG. 11And K2Breaking and detecting the second winding N3The method comprises the following specific steps:
a. to the first winding N2Is electrified with current C1；
b. Detecting the second winding N3In which the current C is generated by mutual electromagnetic induction2；
c. Calculating the current C1And current C2Error data e of22；
d. Comparison of error data e21And error data e22Judging the second winding N3Whether a failure has occurred.
③: second winding N3As a new primary winding, a first winding N2As a secondary winding, a self-calibration module is formed, i.e. the switch K shown in FIG. 11And K2Breaking and detecting the first winding N2The method comprises the following specific steps:
a. to the second winding N3Is electrified with current C1；
b. Detecting the first winding N2In which the current C is generated by mutual electromagnetic induction2；
c. Calculating the current C1And current C2Error data e of12；
d. Comparison of error data e11And error data e12Judging the first winding N2Whether a failure has occurred.
The coil of the extra-high voltage current transformer has larger size and is easy to be interfered by an external magnetic field, and finally the phenomenon of uneven magnetic flux of a magnetic circuit is obvious. In addition, transient current generated in the system commissioning process and the system short-circuit state can reach 50kA to 63kA, and the formed transient magnetic field can generate electric force action on the soft magnetic material of the current transformer coil, so that the soft magnetic material generates a stretching phenomenon in the transient process, the local magnetic conductivity is changed, and strong thermal stress and the like can be generated. Therefore, in this embodiment, a protection box is disposed outside an iron core of the current transformer to serve as a shielding layer to alleviate the phenomenon of inconsistent magnetic fluxes of all parts of the coil of the current transformer, or a means of balancing windings is adopted to alleviate the phenomenon of inconsistent magnetic fluxes of current.
The utility model discloses the specific embodiment of the working process of well CT measurement winding for electric power system's self-checking coil does:
the rated current ratio of the current transformer coil in this embodiment is 3000A: 1A, a lead penetrates through the center of a coil of the transformer by one turn, the secondary output current is 1A, and according to the equal ampere turn principle, when the secondary winding is 3000 turns, the secondary output current is 1A.
And taking the first winding as a new primary winding and the second winding as a secondary winding, and applying a current 1A to the first winding, wherein the second winding theoretically should also generate a current of 1A, and calculating a current error flowing between the first winding and the second winding. And comparing the current error data with current error data which is calculated when the current transformer operates normally and flows through the second winding, so as to judge whether the second winding is short-circuited or damaged. The current error data of the current transformer during normal operation can be obtained through a factory test and a handover test of the current transformer.
Finally, it should be noted that: the described embodiments are only some embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Claims (5)
1. A self-calibration coil of a CT metering winding for an electric power system comprises a primary winding and a secondary winding, and is characterized in that the secondary winding comprises a first winding and a second winding, wherein the first winding and the second winding have the same ampere-turn number;
the two ends of the first winding are provided with connecting terminals, and the two ends of the second winding are also provided with connecting terminals; the middle parts of the connecting terminals are respectively provided with a hollow groove;
the self-calibration coil further comprises a card slot switch:
when the current transformer works normally, the first winding and the second winding are connected in parallel through the slot switch;
when the current transformer carries out self-calibration detection, the first winding and the second winding are disconnected.
2. The self-calibrating coil for a CT metering winding for an electric power system of claim 1 wherein said slot switch comprises an insulated button a1, an insulated button a2, an insulated button b1 and an insulated button b 2; the insulated button a1 is connected with the insulated button b2 through a lead, and the insulated button a2 is also connected with the insulated button b1 through a lead;
each insulated button is provided with a salient point.
3. The self-correcting coil of the CT metering winding for the electric power system as claimed in claim 2, wherein when the first winding and the second winding are connected in parallel by the card slot switch:
the salient point of the insulation button a1 is embedded into the hollow groove of the connecting terminal at one side of the first winding, and the salient point of the insulation button b2 is embedded into the hollow groove of the connecting terminal at the other side of the first winding;
the salient point of the insulation button b1 is embedded into the hollow groove of the connecting terminal at one side of the second winding, and the salient point of the insulation button a2 is embedded into the hollow groove of the connecting terminal at the other side of the second winding.
4. The self-correcting coil of the CT metering winding for the electric power system as claimed in claim 1, wherein the first winding and the second winding are wound on the iron core of the current transformer in a spaced and parallel winding manner.
5. The self-correcting coil of the CT metering winding for the electric power system as claimed in claim 1, wherein a protection box is arranged outside the iron core of the current transformer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520554853.XU CN204855773U (en) | 2015-07-28 | 2015-07-28 | Self -correcting coil of CT measurement winding for electric power system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520554853.XU CN204855773U (en) | 2015-07-28 | 2015-07-28 | Self -correcting coil of CT measurement winding for electric power system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204855773U true CN204855773U (en) | 2015-12-09 |
Family
ID=54746310
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520554853.XU Active CN204855773U (en) | 2015-07-28 | 2015-07-28 | Self -correcting coil of CT measurement winding for electric power system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204855773U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106291431A (en) * | 2016-10-24 | 2017-01-04 | 中国科学院上海应用物理研究所 | A kind of tracking accuracy measuring method of current sensor |
| WO2017016370A1 (en) * | 2015-07-28 | 2017-02-02 | 中国电力科学研究院 | Method of designing ultra-high voltage ct coil having self-calibration function |
| CN107170563A (en) * | 2017-05-09 | 2017-09-15 | 中国电力科学研究院 | A kind of current transformer and its method for self-calibrating with self-calibration function |
| US11538628B2 (en) | 2019-12-02 | 2022-12-27 | Panoramic Power Ltd. | Self calibration by signal injection |
-
2015
- 2015-07-28 CN CN201520554853.XU patent/CN204855773U/en active Active
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017016370A1 (en) * | 2015-07-28 | 2017-02-02 | 中国电力科学研究院 | Method of designing ultra-high voltage ct coil having self-calibration function |
| CN106291431A (en) * | 2016-10-24 | 2017-01-04 | 中国科学院上海应用物理研究所 | A kind of tracking accuracy measuring method of current sensor |
| CN106291431B (en) * | 2016-10-24 | 2018-11-27 | 中国科学院上海应用物理研究所 | A kind of tracking accuracy measurement method of current sensor |
| CN107170563A (en) * | 2017-05-09 | 2017-09-15 | 中国电力科学研究院 | A kind of current transformer and its method for self-calibrating with self-calibration function |
| US11538628B2 (en) | 2019-12-02 | 2022-12-27 | Panoramic Power Ltd. | Self calibration by signal injection |
| US11705275B2 (en) * | 2019-12-02 | 2023-07-18 | Panoramic Power Ltd. | Self calibration by double signal sampling |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101551432B (en) | Power distribution network fault positioning method | |
| CN103809070B (en) | The direction earth-fault detecting method and device carried out based on three-phase current change | |
| CN205080251U (en) | Through -flow calibration system of current transformer secondary circuit | |
| CN102540001B (en) | Method of checking alternating current loop of a 500kV transformer substation through carrying out simulated through-type three-phase short circuit | |
| CN105044643B (en) | A kind of extra-high voltage CT coil design approaches with self-checking function | |
| CN204855773U (en) | Self -correcting coil of CT measurement winding for electric power system | |
| CN104698311B (en) | A kind of DC line direct current arrester live detection method | |
| CN204330857U (en) | A kind of isolated neutral system capacitance current proving installation | |
| CN101593964A (en) | The method for longitudinal zero-sequence power direction protection of double-circuit lines on the same pole | |
| CN201438213U (en) | Electronic current transformer polarity measurement system | |
| CN103293507B (en) | The online test method of current transformer error | |
| CN107271776A (en) | A kind of zero load transformer station's phasor measurement test method | |
| CN101614798B (en) | Polarity detection system of electronic transformer | |
| CN107544045B (en) | System and method for detecting error of self-correcting current transformer | |
| CN106653336B (en) | A method of preparing the current transformer with simplification error test function | |
| CN103730879A (en) | Protection device for power utilization system of transformer substation | |
| CN206362860U (en) | A kind of test device of GIS or GIL equipment loop resistance | |
| CN206541018U (en) | A kind of multipoint grounding seeking instrument of voltage transformer | |
| CN109164387A (en) | Generator unit stator winding Injection Current measurement method based on big small-range CT | |
| WO2009021390A1 (en) | A detection device of shunt lead and a detection method thereof | |
| CN105319478A (en) | Un-disassembly polarity and transformation ratio testing method for transformer bushing | |
| CN206378585U (en) | A kind of current transformer inductance C-V characteristic detection device | |
| CN201464596U (en) | Electronic transducer polarity detecting system | |
| CN105225816A (en) | A kind of current transformer with high voltage standard capacitor function | |
| CN104614698A (en) | Three-phase analogue loader for field calibration of energy measurement device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |