CN105223450B - Transformer core state on_line monitoring method - Google Patents
Transformer core state on_line monitoring method Download PDFInfo
- Publication number
- CN105223450B CN105223450B CN201510724315.5A CN201510724315A CN105223450B CN 105223450 B CN105223450 B CN 105223450B CN 201510724315 A CN201510724315 A CN 201510724315A CN 105223450 B CN105223450 B CN 105223450B
- Authority
- CN
- China
- Prior art keywords
- transformer
- iron core
- max
- curves
- point
- 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
Landscapes
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Protection Of Transformers (AREA)
Abstract
The invention discloses a kind of transformer core state on_line monitoring methods, the variation of its integral representation magnetic induction density B with transformer side voltage, the variation tendency of magnetic field intensity H will be represented after each side electric current conversion synthesis of transformer with the variation of electric current composite value, respectively using B, H as longitudinal and transverse reference axis, point-by-point mapping, BH curves are reconstructed, the working condition of iron core is identified after quantifying to the graphic feature of BH curves.The present invention can timely and effectively identify the working condition of iron core, and the result of calculation of quantization is provided for saturation unilateral caused by magnetic bias etc., consequently facilitating automatic control system identifies the abnormal operation of iron core immediately, iron core longtime running is avoided in unilateral zone of saturation, it is ensured that the reliability service of transformer equipment.
Description
Technical field
The invention belongs to technical field of power systems, and in particular to a kind of transformer core state on_line monitoring method.
Background technology
As the key equipment of power transmission and transformation, transformer is widely used in electric system, and iron is selected when manufacturing and designing
The working range of core avoids the iron core when rated voltage is run from entering saturation region, with the cost control of manufacture, the work of iron core
Point is constantly close to saturation region.When sun generation magnetic storm time, pass through the quasi- DC current of earth induction in power grid（ 0.01~0.1Hz
）Transformer DC magnetic bias can be caused to run, DC transmission system is in line residual current mode（Including monopolar ground circuit operation mode and double
Extremely uneven mode）During operation, it can also cause the D.C. magnetic biasing problem of part neutral grounded transformer in AC network.Direct current
Magnetic bias makes transformer core enter unilateral zone of saturation winding, since core sataration causes exciting current increased dramatically, causes to leak
Magnetic flux increases, vibration aggravation, noise increase, continuous excessive vibration and the mistake due to parts local caused by leakage field increase
Heat influences the reliability of inside transformer Mechanical Structure Strength and insulating materials, and unfavorable shadow is generated to the reliability service of transformer
It rings.
Since transformer core can not directly carry out the measurement of magnetic field intensity, transformer core in can not being run at present
Actual working state information, in order to avoid magnetic bias is run, monitored at present by the neutral point direct current to transformer and
Switching neutral point direct current restraining device is taken to limit the operation of the magnetic bias of iron core, but due to transformer device structure and manufacturing process not
Together and the difference of transformer load state, it is unilateral full can not directly to judge whether iron core enters by the size of DC current
And state, although can be by noise and vibration detection auxiliary judgment, but still intuitively can not accurately obtain the work of iron core
State.
Invention content
The technical problems to be solved by the invention are to provide a kind of transformer core state on_line monitoring method, can and
When effectively identify the working condition of iron core, and the result of calculation of quantization is provided for saturation unilateral caused by magnetic bias etc., so as to
It identifies the abnormal operation of iron core immediately convenient for automatic control system, avoids iron core longtime running in unilateral zone of saturation, really
Protect the reliability service of transformer equipment.
The present invention is to solve above-mentioned technical problem by following technical proposals：A kind of transformer core state is supervised online
Survey method, which is characterized in that the transformer core state on_line monitoring method is with the integral representation magnetic of transformer side voltage
The variation of induction B will represent the change of magnetic field intensity H with the variation of electric current composite value after each side electric current conversion synthesis of transformer
Change trend, respectively using B, H as longitudinal and transverse reference axis, point-by-point mapping reconstructs BH curves, finds out B, H axis direction of BH curves respectively
Maximum A (H_max, B_max), minimum C (H_min, B_min) and new central point D（0, (B_max+B_min)
/ 2）, it is four quadrants that new reference frame is built by origin of new central point D by BH curve segmentations, is then obtained respectively
First quartile, extreme point is formed with reference axis in two quadrants of third rectangular area S1, S3, are calculated in new coordinate system
The BH curve asymmetric degree k_asy of BH curvilinear characteristics are characterized, the work of iron core is identified after quantifying to the graphic feature of BH curves
Make state.
Preferably, the degree of asymmetry k_asy computational methods are as follows：
S1 = | H_max * (B_max –(B_max + B_min) / 2) |;
S3 = | H_min * (B_min –(B_max + B_min) / 2) |;
k_asy=( S1 - S3 ) / ( S1 + S3 )。
Preferably, the direction of the current iron core magnetic bias of positive negative indication of the BH curve asymmetrics degree k_asy.
The positive effect of the present invention is：For the transformer of operation, iron core state of the present invention after quantization
Change curve can be drawn out in monitor screen as real time data, while by setting alarm threshold value, realization, which is worked as, to be detected
Automatic alarm during iron core abnormality；Iron core status data after quantization is fed back in microcomputer protecting device, is improved micro-
The accuracy of machine protective device identification avoids the occurrence of the maloperation situation of conventional principle protection；Iron core status number after quantization
According to for controlling the working condition of direct current restraining device, transformer long-play under D.C. magnetic biasing is avoided；It is applicable not only to
Iron core on-line checking with high pressure, the two-winding transformer of two groups of voltage of low pressure, for the above-mentioned inspection of the transformer of more Multiple coil
Survey method equally uses, and need to only change the composite calulation mode of electric current according to the structure of transformer.The present invention passes through to becoming
The analysis of depressor operation principle with reference to the iron core variation characteristic of transformer under different working condition, uses voltage and current data weight
Structure goes out the BH curves that can reflect iron core working condition in real time, whether enters unilateral saturation according to the feature recognition iron core of BH curves
State, and a kind of quantized data that can reflect iron core working condition is provided, it is online that the present invention can be applied not only to iron core
Monitoring system, neutral point direct current restraining device switching control system, while can also apply and be used for carrying in microcomputer protecting device
The reliability and correctness of high protective device.
Description of the drawings
Fig. 1 is single-phase transformer both sides CT（Current transformer）Arrange schematic diagram.
Fig. 2 is single-phase transformer voltage and current and magnetic flux schematic diagram.
Fig. 3 is the practical hysteresis loop of different conditions lower core.
Fig. 4 is the schematic diagram calculation of BH curve asymmetric degree.
Fig. 5（a）High side voltage curve synoptic diagram during for Transformer magnetic bias.
Fig. 5（b）High voltage side current curve synoptic diagram during for Transformer magnetic bias.
Fig. 5（c）Low-pressure side current curve schematic diagram during for Transformer magnetic bias.
Fig. 6 is exciting current schematic diagram when D.C. magnetic biasing occurs in Transformer.
There are the BH curve synoptic diagrams reconstructed during D.C. magnetic biasing for Transformer in Fig. 7.
Fig. 8 is the schematic diagram of iron core BH curve asymmetric degree when D.C. magnetic biasing occurs in Transformer.
Specific embodiment
Present pre-ferred embodiments are provided below in conjunction with the accompanying drawings, with the technical solution that the present invention will be described in detail.
The present invention can be used in the on-line monitoring of transformer core working condition, and lower mask body is mono- with 500kV/110kV
Phase two-winding transformer come illustrate the present invention concrete application.
102 high-low pressure both sides of 500kV/110kV double windings single-phase transformer as shown in Figure 1 are configured with two groups of CT, i.e., high
Side CT101, low-pressure side CT103 are pressed, with reference to the CT mounting means of differential protection, " * " institute in the Same Name of Ends such as Fig. 1 of CT near CT
Show, towards transformer outside, used alternating current voltage frequency is power frequency 50Hz, on high-tension side voltage, on high-tension side electricity
The electric current progress high-speed data acquisition of stream, low-pressure side, according to CT no-load voltage ratios, is converted to primary electricity by collected both sides electric current automatically
Stream, so as to internal calculation processing, voltage then remains as secondary voltage.
Both sides voltage, electric current and the interior flux of double winding single-phase transformer are as shown in Fig. 2, wherein U1, I1 are high pressure
The voltage and current of side, U2, I2 are the voltage and current of low-pressure side, and Φ 1, Φ 2 are respectively the corresponding magnetic of high-low pressure both sides electric current I1, I2
Logical, Φ m are the residual flux after Φ 1, Φ 2 cancel out each other, the working condition for being sized to performance iron core of Φ m.
According to IEC standard, the definition of inflection point is：In some operating point, when increasing by 10% in this operating point magnetic flux, with
This simultaneously electric current increase by 50% when, this point is known as inflection point.The magnetic that rated voltage has been controlled to run during design of transformer
Hysteresis curves will not enter saturation region within inflection point.Fig. 3 is the practical hysteresis loop of different conditions lower core, in rated voltage
Under the hysteresis loop of no magnetic bias or remanent magnetism when running as shown in the first curve 301 in Fig. 3, both sides do not enter saturation region
Domain；Hysteresis loop when there is D.C. magnetic biasing or remanent magnetism is as shown in the second curve 302 in Fig. 3, into unilateral zone of saturation；
When overtension, iron core is by as shown in the third curve 303 in Fig. 3, into two-way zone of saturation.
Shown magnetic flux composition principle according to fig. 2 converts low-pressure side electric current to after high-pressure side according to the no-load voltage ratio of transformer
Carry out cancelling out each other for corresponding magnetic flux, it is contemplated that iron loss occur during saturation and corresponding current components are lost in exciting current in other
In ratio reduce, both sides current canceling synthesis after residual current be mainly used to establish residual flux Φ m, for this TV station transformation
Device is the transformer of 500kV/110kV, and the calculation formula of the engineering approximation value of exciting current Im is formula（1）：
Im = I1 – I2/(500/110)……（1）
Use Im and high side voltage U1, you can draw the BH curves for representing iron core variation, according to the BH curves of Fig. 4 not
The Computing Principle of symmetry, you can BH curve asymmetric degree during magnetic bias is obtained, is as follows：
To high side voltage U1 and both sides electric current（High voltage side current I1, low-pressure side electric current I2）Carry out high speed digital sample,
Voltage and current is converted to the sample data sequence for characterizing its change procedure, then according to formula（1）The excitation of iron core is obtained
Electric current Im.According to the sample rate of data, the voltage of a complete cycle before interception current time（U1）Electric current（Im）Sampling
Data sequence, when supply voltage frequency is 50Hz, that is, the sample data sequence of 20ms, to voltage（U1）Data sequence into
The B_one_wave sequences obtained after row Integral Processing, as the variation of magnetic induction density B, electric current（Im）Data are as H_
The variation of one_wave sequences performance magnetic field intensity H, on two dimensional surface, using H_one_wave sequences as the magnetic of horizontal direction
The coordinate data of field intensity H axis, coordinate data of the B_one_wave sequences as the magnetic induction density B axis of vertical direction use
Above-mentioned two groups of data sequences construct BH curves shown in Fig. 4.Max functions are used for finding out the maximum value in specified data sequence,
Min functions are used for finding out the minimum value in specified data sequence, find out B, H axis of this cycle BH curves respectively using max, min
The maximum value minimum in direction, specific procedure processing are as follows：
BH curve H axis direction maximum point H_max=max (H_one_wave)；
BH curve H axis direction minimum point H_min=min (H_one_wave)；
BH curve B axles direction maximum point B_max=max (B_one_wave)；
BH curve B axles direction minimum point B_min=min (B_one_wave)；
Based on above-mentioned data, in Fig. 4 the coordinate of 2 points of A, C of BH curves be respectively A (H_max, B_max), C (H_min,
B_min), since power supply is AC mode, according to the centre-symmetric properties of alternating current, the BH curve H axis directions reconstructed are equivalent
Center is always " 0 ", i.e. X0=0 in D point coordinates, and B axle direction center Y0=(YB_max+B_min)/2, therefore D points are sat
It is designated as D（0, (B_max+B_min)/2）, new reference frame is built as origin using D points, horizontal axis, the longitudinal axis are bent by BH
Line is divided into four quadrants, specific as shown in Figure 4.Then be obtained respectively in new coordinate system 2 points of A, C first, third two as
Rectangular area S1, the S3 formed in limit with reference axis, wherein S1, S3 concrete composition is as shown in the dash area in Fig. 4, accordingly
This BH curve asymmetric degree k_asy are calculated, it is as follows to calculate step：
S1 = | H_max * (B_max –(B_max + B_min) / 2) |;
S3 = | H_min * (B_min –(B_max + B_min) / 2) |;
k_asy=( S1 - S3 ) / ( S1 + S3 )。
According to above-mentioned BH asymmetry measurements principle, magnetic bias degree influences the size of degree of asymmetry, the direction of magnetic bias then shadow
Ring the positive and negative of degree of asymmetry k_asy.
Fig. 5（a）、（b）、（c）Respectively Transformer magnetic bias when high side voltage, high voltage side current, low-pressure side
Current curve, as seen from Figure 5, when iron core enters unilateral saturation, since load current is larger, high voltage side current I1 is without bright
The feature of exciting current, can not effectively identify, the ratio of only excitation surge current and load current increases to one during aobvious saturation
Exciting current feature when high voltage side current I1 just shows unilateral saturation when determining degree.
According to formula（1）, after carrying out synthesis processing to the electric current of transformer high-low-voltage both sides, obtain transformer bias when
Exciting current is as shown in Figure 6, it can be seen that has apparent saturation exciting current feature, uses this exciting current and high-pressure side electricity
Ballast structure goes out the BH curves of iron core as shown in fig. 7, horizontal axis is magnetic field intensity H in Fig. 7, and the longitudinal axis is magnetic induction density B, can from Fig. 7
To find out that iron core significantly enters unilateral zone of saturation winding.
During voltage and current data sampling, it is repeated in the reconstruct of above-mentioned BH curves point by point to voltage and current data sequence
It, can from Fig. 8 so as to which BH curve asymmetrics are write music line during obtaining magnetic bias as shown in Figure 8 with asymmetry measurement process
Going out the calculating of BH curve asymmetric degree needs previous complete cycle（20ms）Data, in actual operation, due to voltage electricity
The continual continuous collecting of flow data will not impact the on-line monitoring of iron core.
For the transformer of operation, the iron core state after quantization can analyze the work of iron core as record storage
Make state, in addition it can draw out change curve in monitor screen as real time data, while by setting alarm threshold value,
Realize the automatic alarm when detecting iron core abnormality；Iron core status data can also feed back to microcomputer protecting device simultaneously
In, in Transformer Close and operation during overexcitation, the accuracy of microcomputer protecting device identification is improved, avoids the occurrence of traditional original
Manage the maloperation situation of protection；It can also be used for controlling the working condition of direct current restraining device according to iron core state simultaneously, have in time
Taking measures for effect, avoids transformer long-play under D.C. magnetic biasing.
The present invention can also utilize the existing voltage and current gathered data in transformer differential protection both sides in a particular application,
Hardware need not be increased, data are carried out using software to handle in real time, by the reconstruct of iron core BH curves so as to obtain iron core
Flux change process, be used as differential protection judgement be used, such as is used as excitation surge current criterion, improve improvement now
There is the product function of differential protection.
The present invention can timely and effectively identify the working condition of iron core, and be provided for saturation unilateral caused by magnetic bias etc.
The result of calculation of quantization consequently facilitating automatic control system identifies the abnormal operation of iron core immediately, avoids iron core from transporting for a long time
Row is in unilateral zone of saturation, it is ensured that the reliability service of transformer equipment.
The present invention can be applied monitors field on-line in transformer core, under rated operational voltage, passes through voltage and current
Real-time Reconstruction BH curves can realize automatic monitoring, as D.C. high voltage transmission is to AC transmission system according to degree of asymmetry
Getting worse is influenced, this monitoring method is of great significance.
Above-mentioned transformer core state on_line monitoring method can not only be used for monitoring iron core on-line, while may be used also
To be used for detection and identification into line transformer working condition, such as iron under excitation surge current, overexcitation and echo surge current state
The identification of core judges.
Foregoing description illustrate to have high pressure, two groups of voltage of low pressure two-winding transformer iron core online test method,
The above-mentioned detection method of the transformer of more Multiple coil is equally used, need to only change the synthesis meter of electric current according to the structure of transformer
Calculation mode.
The present invention is directed to the D.C. magnetic biasing problem of transformer, by the analysis to transformer working principle, with reference to different works
Make the iron core variation characteristic of transformer under state, iron core working condition can be reflected in real time by going out using voltage and current data reconstruction
Whether BH curves enter unilateral saturation state, and provide one kind to reflect iron core according to the feature recognition iron core of BH curves
The quantized data of working condition, the present invention can be applied not only to iron core on-line monitoring system, neutral point direct current restraining device is thrown
Control system is cut, while can also apply and be used for the reliability and correctness that improve protective device in microcomputer protecting device.This
Invention can timely and effectively identify the working condition of iron core, and the calculating of quantization is provided for saturation unilateral caused by magnetic bias etc.
As a result, consequently facilitating automatic control system identifies the abnormal operation of iron core immediately, avoid iron core longtime running full in unilateral side
And region, it is ensured that the reliability service of transformer equipment.
The present invention is rolled over each side electric current of transformer with the variation of the integral representation magnetic induction density B of transformer side voltage
The variation tendency for representing magnetic field intensity H after synthesizing with the variation of electric current composite value is calculated, respectively using B, H as longitudinal and transverse reference axis, point by point
It draws, reconstructs BH curves, the working condition of iron core is identified after quantifying to the graphic feature of BH curves.To the figure of BH curves
The step of shape characteristic quantification, is as follows：The maximum value minimum of B, H axis direction of BH curves and new central point are found out respectively,
It is four quadrants that new reference frame is built by origin of new central point by BH curve segmentations, is then obtained and is sat newly respectively
It marks first quartile in system, rectangular area S1, S3 that extreme point is formed with reference axis in two quadrants of third, characterization BH is calculated
BH song degrees of asymmetry k_asy=(S1-S3)/(S1+S3) of curvilinear characteristic.The current iron of positive negative indication of degree of asymmetry
The direction of core magnetic bias；Electric current composite value is the exciting current of iron core, will be each on the basis of using the voltage of transformer voltage side
Side electric current is according to the voltage of transformer than subtracting each other the exciting current so as to find out iron core after being converted；It is adopted in voltage and current data
During sample, the reconstruct of BH curves and asymmetry measurement process are repeated in point by point to voltage and current data sequence, so as to obtain
The degree of asymmetry curve of BH curves；For the transformer of operation, the iron core state after quantization can exist as real time data
Draw out change curve in monitor screen, while by setting alarm threshold value, realize when detecting iron core abnormality from
Dynamic alarm；Iron core status data after quantization is fed back in microcomputer protecting device, is improving microcomputer protecting device identification just
True rate avoids the occurrence of the maloperation situation of conventional principle protection；Iron core status data after quantization is used for that direct current is controlled to inhibit
The working condition of device avoids transformer long-play under D.C. magnetic biasing；It is applicable not only to two groups of high pressure, low pressure electricity
The iron core on-line checking of the two-winding transformer of pressure equally uses the above-mentioned detection method of the transformer of more Multiple coil, only needs
Change the composite calulation mode of electric current according to the structure of transformer.
The attached drawing of this specification is used to provide further understanding of the present invention, and forms the part of the application, the present invention
Illustrative embodiments and their description for explaining the present invention, do not constitute improper limitations of the present invention.
The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field
For art personnel, the invention may be variously modified and varied, and that is made all within the spirits and principles of the present invention any repaiies
Change, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.
Claims (2)
- A kind of 1. transformer core state on_line monitoring method, which is characterized in that the transformer core state on_line monitoring side Method is with the variation of the integral representation magnetic induction density B of transformer side voltage, with electricity after each side electric current conversion of transformer is synthesized The variation for flowing composite value represents the variation tendency of magnetic field intensity H, and respectively using B, H as longitudinal and transverse reference axis, point-by-point mapping reconstructs BH curves, find out respectively maximum A (H_max, B_max), the minimum C (H_min, B_min) of B, H axis direction of BH curves with And new central point D（0, (B_max+B_min)/2）, building new reference frame as origin using new central point D will BH curve segmentations are four quadrants, be then obtained respectively in new coordinate system first quartile, in two quadrants of third extreme point with The BH curve asymmetric degree k_asy of characterization BH curvilinear characteristics are calculated in rectangular area S1, S3 that reference axis is formed, to BH songs The graphic feature of line identifies the working condition of iron core after being quantified；The degree of asymmetry k_asy computational methods are as follows：S1 = | H_max * (B_max –(B_max + B_min) / 2) |;S3 = | H_min * (B_min –(B_max + B_min) / 2) |;k_asy=( S1 - S3 ) / ( S1 + S3 )。
- 2. transformer core state on_line monitoring method as described in claim 1, which is characterized in that the BH curve asymmetrics Spend the direction of the current iron core magnetic bias of positive negative indication of k_asy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510724315.5A CN105223450B (en) | 2015-11-02 | 2015-11-02 | Transformer core state on_line monitoring method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510724315.5A CN105223450B (en) | 2015-11-02 | 2015-11-02 | Transformer core state on_line monitoring method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105223450A CN105223450A (en) | 2016-01-06 |
| CN105223450B true CN105223450B (en) | 2018-06-26 |
Family
ID=54992515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510724315.5A Active CN105223450B (en) | 2015-11-02 | 2015-11-02 | Transformer core state on_line monitoring method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105223450B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106026022B (en) * | 2016-08-14 | 2018-11-16 | 卢庆港 | Power system excitation inrush current identification method based on reconstruct BH curvilinear characteristic |
| CN106371044B (en) * | 2016-08-22 | 2018-11-16 | 卢庆港 | A kind of box house iron core work state monitoring method based on leakage field |
| CN108318732B (en) * | 2018-03-13 | 2024-01-23 | 国家电网公司 | On-line monitoring device and method for grounding current of transformer core |
| CN109541506A (en) * | 2018-10-16 | 2019-03-29 | 中国电力科学研究院有限公司 | A kind of measurement of power transformer iron core magnetic characteristic and analytical equipment |
| CN111505404A (en) * | 2019-11-19 | 2020-08-07 | 宁波金源控股有限公司 | Frequency and voltage stabilizing lifting transformer and frequency and voltage stabilizing method |
| CN115541594B (en) * | 2022-10-09 | 2023-04-25 | 江阴市晶磁电子有限公司 | Intelligent analysis system for coil layout |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102545156B (en) * | 2012-01-13 | 2014-10-22 | 中国电力科学研究院 | Exciting current emulation calculating method and device at time of direct-current magnetic biasing |
| CN202600121U (en) * | 2012-04-14 | 2012-12-12 | 河北工业大学 | Device for obtaining hysteresis loop of dc biasing of transformer iron-core material |
| CN103675415B (en) * | 2012-08-31 | 2017-03-01 | 西门子公司 | Excitation surge current detection method, braking magnetizing inrush current method and its device |
| CN103513212B (en) * | 2013-09-12 | 2016-01-27 | 卢庆港 | Based on the CT state recognition of BH curvilinear characteristic and the degree of unsaturation computing method of reconstruct |
| CN103439675B (en) * | 2013-09-27 | 2015-12-02 | 卢庆港 | Based on the demagnetizing method that the BH curve asymmetric degree variation tendency of reconstruct monitors |
| CN103577633B (en) * | 2013-10-18 | 2016-04-06 | 国家电网公司 | A kind of transformer DC magnetic bias raised based on earth potential is simulated and suppressing method |
| CN104849587A (en) * | 2015-04-30 | 2015-08-19 | 国网四川省电力公司电力科学研究院 | Method for analyzing excitation characteristic change of transformer under influence of direct-current magnetic bias |
-
2015
- 2015-11-02 CN CN201510724315.5A patent/CN105223450B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN105223450A (en) | 2016-01-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105223450B (en) | Transformer core state on_line monitoring method | |
| CN105158543B (en) | Based on double Hall elements to the collecting unit of UHVDC Arrester leakage current | |
| CN103713217A (en) | Method for monitoring operating state of power transformer on line under direct-current magnetic bias condition | |
| CN204256093U (en) | The On-line Fault monitoring device of cable splice in a kind of 10 ~ 35kV power distribution network | |
| CN110687408B (en) | Cable insulation monitoring method and device | |
| CN103245860B (en) | CT (current transformer) saturation detection method based on morphological gradient wavelets | |
| CN103513125A (en) | Integrated intelligent diagnosis system and method of above-220KV transformers | |
| CN104330660A (en) | Power transformer DC magnetic bias state detection method based on noise method | |
| CN113673083B (en) | Transformer direct-current magnetic bias risk assessment method | |
| CN111751645B (en) | Method, device, equipment and system for monitoring DC magnetic bias of transformer | |
| CN105182261B (en) | Coil inside core field intensity contactless measurement | |
| Wang et al. | Identification of series arc fault occurred in the three-phase motor with frequency converter load circuit via VMD and entropy-based features | |
| CN105301323B (en) | The method that UHVDC Arrester Leakage Current is detected online using cloud | |
| CN106371044B (en) | A kind of box house iron core work state monitoring method based on leakage field | |
| CN110060445A (en) | Prevent the method and detector for electric fire protection, monitoring system of electric leakage false alarm | |
| CN103675560A (en) | Online identifying method for detuning of direct current side filter of high-voltage direct current transmission system | |
| CN107153154B (en) | A kind of two sides earth cable insulation deterioration diagnosis method | |
| CN104062555A (en) | Identification method for distributing line high-resistance ground fault feature harmonic waves | |
| CN105158633B (en) | The method of UHVDC Arrester state on-line checking data is shared with cloud platform | |
| CN113514728B (en) | Fault arc detection device and method and three-phase circuit fault detection method | |
| CN115327446A (en) | Transformer direct-current magnetic bias cause identification method and system | |
| CN113899985B (en) | Intelligent detection method for state of distribution line grounding wire | |
| CN110231541B (en) | Method for carrying out inverse calculation on equivalent electrical parameters of system based on online monitoring of damped oscillation waves | |
| CN105182043B (en) | Detection device with non-contact sensor to UHVDC Arrester leakage current | |
| Quan et al. | The application of Bayesian network theory in transformer condition assessment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB03 | Change of inventor or designer information | ||
| CB03 | Change of inventor or designer information |
Inventor after: Le Xiaorong Inventor after: Lu Qinggang Inventor before: The inventor has waived the right to be mentioned |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |