• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    System and method for locating ground faults in electrical machine windings. Method and system for locating ground faults (4) in windings (3) of electrical machines based on the frequency response analysis of the machine circuit, feeding the terminals of the winding (3) to be analyzed, in a device (11) fault locator that compares the parameters of resonance frequency (fR) and gain of the system at said resonance frequency (AfR) with a database of surfaces produced from previous tests and that allows locating the fault in fault turn number (n) and fault resistance (Rf). (Machine-translation by Google Translate, not legally binding)
    公开号:ES2848598A1
    申请号:ES202031319
    申请日:2020-12-30
    公开日:2021-08-10
    发明作者:Granados José Manuel Guerrero；Santos Carolina Martin；Gaona Carlos Antonio Platero
    申请人:Universidad Politecnica de Madrid；
    IPC主号:
    专利说明:

    [0004] OBJECT OF THE INVENTION
    [0005] The present invention refers to a method and system for locating ground faults in windings of electrical machines capable of locating this type of fault while being at any point in the electrical circuit, with it disconnected from the electrical network.
    [0007] The method and system for locating ground faults in electrical windings according to the present invention is useful for the maintenance, mainly corrective, of electrical machines and can also be applied in predictive maintenance thanks to the fact that said system allows obtaining the resistance of defect of a possible fault in the electrical system, as well as the number of turn where the defect is found.
    [0009] BACKGROUND OF THE INVENTION
    [0010] Throughout the useful life of electrical machines, one of the most common failures that such machinery can experience is the appearance of earth faults.
    [0012] These faults put the integrity of the machines at risk and can directly affect an alteration in their operation or cause severe damage to adjacent machines or the health of nearby workers.
    [0014] The field of diagnostics is then in charge of detecting and locating these faults to avoid the appearance of these types of faults among others or, failing that, to proceed with a rapid protection of the electrical system in question.
    [0016] There are many systems that are responsible for detecting or locating earth faults in electrical machines, for example, the systems shown in the following documents:
    [0017] Patent US 6794879 B2 entitled "Apparatus and method for detecting and calculating ground fault resistance" refers to an invention that diagnoses faults in the field winding of synchronous machines. It uses square wave injection between the excitation power supply terminals, and depending on the deformation of said square wave in the downstream sensor, the location of the fault in the inductor winding as well as the fault resistance can be estimated.
    [0019] Patent US 10429419 B2 entitled "System and method for iterative condition monitoring and fault diagnosis of electric machines" refers to an invention that analyzes the current signal of the stator currents and determined harmonics in order to detect possible faults such as eccentricities in the machines.
    [0021] Patent DE 102001003021 B4 entitled "Methods and apparatus for diagnosing stator windings in an electric motor ' refers to a method and system for diagnosing faults in stators of electrical machines that by measuring current and voltage and comparing them in reverse sequence With certain pre-established references, it is capable of detecting faults in said windings.
    [0023] The patent ES 2454045 A1 entitled "System and method for locating ground faults in stator windings of synchronous machines grounded by means of a high impedance based on the estimation of the fault resistance at low frequency" refers to a system and method in which earth faults are located by using variables from a measurement stage and the injection of a low frequency voltage wave between the neutral of a synchronous generator and earth.
    [0025] Finally, the patent application P202030371 "System and method for locating ground faults in electrical windings" uses the frequency response analysis technique to locate ground faults, however in this method two tests have to be carried out to the winding, injecting at both ends.
    [0027] To locate defects and faults in stopped or off-line machines, it is usually uses the frequency response analysis technique, or FRA, especially in transformers in which it is intended to locate faults between turns, or the movement of the windings of said transformers during transport or after overcurrents.
    [0029] This technique comprises injecting a sinusoidal voltage wave with a fixed amplitude normally of 1 or 10 V with a variable frequency between 10 Hz and 20 MHz and the recording of the output voltage at the other end of the circuit to be analyzed into a resistance of known value. By obtaining the transfer function, the gain and phase parameters are obtained, which are used for failure analysis.
    [0031] FRA tests are -usually- capable of detecting the existence of earth faults. However, it is much less frequent that said tests allow obtaining the location of said faults. Here are several ways to detect defects with this technique:
    [0033] In the article "Y. Liu et al.," A study of the sweep frequency impedance method and its application in the detection of internal winding short circuit faults in power transformers, " in IEEE Transactions on Dielectrics and Electrical Insulation, vol.
    [0034] 22, no. 4, pp. 2046-2056, August 2015 ”discloses an analysis method using the FRA technique focused on its impedance analysis (SFI). By observing fluctuations in the gain amplitude of the system, it detects and quantifies possible faults between turns in transformers, but without referring to their location.
    [0036] In the article “J. Nosratian Ahour, S. Seyedtabaii and GB Gharehpetian, "Determination and localization of turn-to-turn fault in transformer winding using frequency response analysis," in IET Science, Measurement & Technology, vol.
    [0037] 12, no. 3, pp. 291-300, 5 2018. " The invention relates to a method for the detection and location of faults between turns with the same FRA system. This method is based on the comparison of patterns calculated by means of a mathematical model and the FRA gain obtained in the direct test to the transformer. Unlike the previous method, this one is able to estimate the location of the fault by sections of the winding.
    [0038] Other fault diagnosis techniques in systems with windings are linked to artificial intelligence (AI) and the learning of the AI itself over time in the adjustment of models that are then used to contrast with the FRA diagnoses collected from the equipment. In the article "V. Nurmanova, M. Bagheri, A. Zollanvari, K. Aliakhmet, Y. Akhmetov and GB Gharehpetian," A New Transformer FRA Measurement Technique to Reach Smart Interpretation for Inter-Disk Faults, " in IEEE Transactions on Power Delivery, vol. 34, no. 4, pp.
    [0039] 1508-1519, Aug. 2019. " This technique is used for systems with faults between turns or between winding discs for electrical transformers.
    [0041] Finally, in the article “A. Mugarra, CA Platero, JA Martínez and U. Albizuri-Txurruka, "Validity of Frequency Response Analysis (FRA) for Diagnosing Large Salient Poles of Synchronous Machines," in IEEE Transactions on Industry Applications, vol. 56, no. 1, pp. 226-234, Jan.-Feb. 2020. " the FRA is covered for inter-turn faults as well as for earth faults. However, we do not proceed to the location of any type of them, but to their detection by observing the resonance frequency of the tested system.
    [0043] Looking at the state of the art, it is concluded that it is necessary to establish new systems and methods of FRA analysis for the location of earth faults in electrical machines in such a way that they make this a simple process to execute and easy to interpret. Furthermore, it would be advantageous if said earth fault location systems and methods were able to obtain the location (n) and the magnitude of the fault in ohmic fault resistance (Rf) values.
    [0045] DESCRIPTION OF THE INVENTION
    [0046] The present invention seeks to address all the disadvantages and drawbacks of the prior art. For this, the invention contemplates a system and a method for locating ground faults in windings of electrical machines based on the technique of analyzing the frequency response of the machine circuit.
    [0048] More specifically, a first object of the invention refers to a method for locating ground faults in windings of electrical machines, of the type based on frequency response analysis, characterized in that it comprises -at least- the following stages:
    [0050] a) injecting electrical signals of variable frequency and constant amplitude through a terminal of the faulty winding of the electrical machine and measuring in the opposite terminal of said winding -at least- the corresponding gain, phase and frequency;
    [0051] b) calculating the phase and gain transfer functions as a function of the gain, phase and frequency measurements obtained in the previous stage;
    [0052] c) obtain the resonance frequency (f R) for the faulty winding; d) obtaining the gain A (f R ) corresponding to the resonance frequency (f R ) of the faulty winding;
    [0053] e) Obtain a resonance frequency cut-off curve from a database that includes fault emulations at different fault resistances (R f ) and in different turns for a typical winding, where (n) is the number of turns in fault, determining the resonance frequency of the faulty winding by matching a plane parallel to the axes Rf and n, in such a way that f R = cte, obtaining a two-dimensional curve -which depends exclusively on the parameters R f and n - produced by the cut between said plane (f R = cte) and the resonance frequency cut-off curve -in three dimensions- of the database; f) Obtain a constant gain cut-off curve from a database that includes values from previous fault tests at different fault resistances and in different turns for a typical winding, determining the gain for the resonance frequency of the winding at fault by matching a plane parallel to the axes Rf and n in such a way that A ( fR) = cte, obtaining a two-dimensional curve -which depends exclusively on the parameters R f and n, produced by the cut between said plane (A (f R ) = cte) and the constant gain cut-off curve -in three dimensions- of the database;
    [0054] g) determine the fault turn number (n) and the fault resistance (R f ) of the faulty winding of the electrical machine as the cut-off point between the resonance frequency cut-off curve and the gain cut-off curve constant; and
    [0055] h) Issue the fault information once the fault loop number and fault resistance signals have been collected to an external monitoring device or protection relay.
    [0057] In a preferred embodiment of the invention, in step c) indicated above, the frequency the resonance frequency fR is the frequency value for which the frequency response of the winding phase is zero (in other words, when the circuit electrical is purely resistive).
    [0059] In a preferred embodiment of the invention, in step e) indicated above, the fault emulations are functions of the spatial surface type that depend on the number of fault turns (n), the fault resistance (Rf) and the frequency resonance (fR).
    [0061] In a preferred embodiment of the invention, in step f) indicated above, the values of previous fault tests are functions of the spatial surface type that depend on the number of fault turns (n), the fault resistance, (Rf) and the gain assigned to the resonance frequency, A (fR).
    [0063] A second aspect of the invention refers to a system for locating ground faults in windings of electrical machines, of the type based on frequency response analysis, provided with:
    [0065] - a voltage injection device at variable frequency and constant amplitude between a terminal of the faulty winding and a reference to ground; - a calibrated measurement impedance, connected between the other terminal of the faulty winding and a reference to ground;
    [0066] - an output meter configured to measure the calibrated measurement impedance between the terminals, determine the gain and phase of the winding as a function of the injection frequency and send said information to a receiver;
    [0068] characterized in that it is also provided with a ground fault location device comprising -at least- the following elements:
    [0069] - a receiver, configured to receive the frequency, phase and gain measurements obtained by the output meter;
    [0070] - phase and gain transfer function constructor means, configured to calculate the phase and gain transfer function from the output meter's frequency, phase and gain measurements;
    [0071] - means for calculating the resonance frequency and gain, configured to calculate the resonance frequency fR and the gain at said resonance frequency A (fR) of the faulty winding, from the frequency, phase and gain measurements of the power meter. Exit;
    [0072] - a device for storing databases of previous tests of faults in a typical winding, in which faults have been emulated in different turns and with different fault resistances, the databases being configured to provide the number of turns (n ) of the earth fault from the resonant frequency and gain for said resonant frequency;
    [0073] - cutoff curve calculating means, configured to calculate a cutoff curve of resonance frequency and a cutoff curve of constant gain from the values of resonance frequency and gain of the tested winding included in the database;
    [0074] - a fault locator, configured to find the cut-off point of the curves obtained by the curve calculating means, said cut-off point being a function of the turn number (n) of the fault and the fault resistance (Rf) ; and
    [0075] - an information emitting element configured to send the loop number (n) of the fault and the fault resistance (Rf), obtained by the fault locator.
    [0077] In a preferred embodiment of the invention, the databases of previous tests of fault emulations in the form of functions of the spatial surface type that depend on the number of fault turns (n), the fault resistance (Rf) and the resonant frequency (fR).
    [0078] BRIEF DESCRIPITION OF THE FIGURES
    [0080] A series of drawings that help to better understand the invention are described very briefly below, which expressly relate to an embodiment of said invention and are presented as non-limiting examples thereof.
    [0082] Figure 1 is a wiring diagram of the frequency response analysis system (FRA) of the winding to be tested and the ground fault location system;
    [0084] Figure 2 is a block diagram of the ground fault locating system according to the present invention;
    [0086] Figure 3 is a flow chart of the fault locating method of the invention; and
    [0088] Figure 4 is a graphical representation of the surfaces and curves that are used for ground fault location in the present invention.
    [0090] NUMERICAL REFERENCES OF THE FIGURES
    [0092] (1) Voltage injection terminal.
    [0093] (2) Output voltage measurement terminal;
    [0094] (3) Winding;
    [0095] (4) Ground fault;
    [0096] (5) Device for the injection of electrical signals at variable frequency and constant amplitude;
    [0097] (6) Measurement impedance;
    [0098] (7) Output meter;
    [0099] (8) Reference to ground;
    [0100] (9) Measures collected;
    [0101] (10) Frequency response analysis (FRA) test equipment;
    [0102] (11) Ground fault locating device;
    [0103] (12) Winding gain signal;
    [0104] (13) Winding phase signal;
    [0105] (14) Frequency signal;
    [0106] (15) Frequency response of the winding phase;
    [0107] (16) Frequency response of the winding gain;
    [0108] (17) Resonance frequency;
    [0109] (18) Gain for the resonant frequency;
    [0110] (19) Step of obtaining the resonance frequency cutoff curve from a previously stored database for similar machines or windings;
    [0111] (20) Step of obtaining the constant gain cut-off curve from a previously stored database for similar machines or windings;
    [0112] (21) Database;
    [0113] (21.a) Fault surface for resonance frequencies;
    [0114] (21.b) Fault surface for gains at resonance frequency;
    [0115] (22) Matching of the phase and gain cut-off curves;
    [0116] (23) Missing loop signal;
    [0117] (24) Fault resistance signal;
    [0118] (25) Stage of issuing fault information;
    [0119] (26) Stage of obtaining the resonance frequency;
    [0120] (27) Stage of obtaining the gain at resonance frequency;
    [0121] (28) Cutoff curve at resonance frequency
    [0122] (29) Constant gain cut curve;
    [0123] (30) Z-axis in frequency;
    [0124] (31) Z-axis in gain.
    [0126] DETAILED DESCRIPTION OF THE FIGURES
    [0127] The present invention refers to a system and method for locating ground faults in windings of electrical machines capable of locating said faults by indicating the number of loop and fault resistance between said loop and ground by means of the frequency response analysis of a device. FRA with a frequency sweep that is common practice between 10 Hz and 20 MHz, which is considered sufficient to obtain data relevant to the location of faults in electrical windings.
    [0129] Figure 1 shows the connection diagram of the FRA (10) measuring equipment, which allows obtaining the transfer function of the tested winding where you want to locate an earth fault. Said connections are made in a winding (3) with a ground fault (4) to be located. This has a voltage injection terminal (1) by means of a voltage injection device at variable frequency and constant amplitude (5) and an output voltage measurement terminal (2) connected to a measurement impedance (6) of the equipment where with an output voltage meter (7), connected between said terminal (2) and the ground reference (8) of the FRA equipment (10), it allows at least obtaining measurements (9) of gain and phase in depending on the injection frequency. Said measurements are subsequently transferred to a ground fault location device (11).
    [0131] Figure 2 shows the block diagram of the ground fault locating device (11). First, the collected measurements (9) are collected, which must be at least the gain signal of the winding (12), the phase signal of the winding (13) and the frequency signal (14). Using these data collected by the FRA measurement equipment (10), the transfer functions of the frequency response of the winding phase (15) and the frequency response of the winding gain (16) are constructed.
    [0133] The system and method contemplate the calculation (17) of the resonant frequency of the winding (3) obtaining the frequency value for which the frequency response of the winding (15) phase is zero. Subsequently, with said value of resonance frequency, fR, the system and method considers the use of said parameter to obtain (18) the gain value for the resonance frequency (18) by introducing said value of fR in the frequency response winding gain (16).
    [0135] Once both values have been obtained, the invention contemplates the matching of said values with a database (21), which has surfaces built by previous laboratory tests on similar windings with ground faults carried out at various points with different fault resistances, having built functions of the type:
    [0137] fR = u (n, R f )
    [0138] M.fR) = v (n, R f)
    [0139] Where:
    [0140] n: missing turn number.
    [0141] Rf: fault resistance.
    [0142] fR: resonance frequency.
    [0143] A (fR): is the gain of the system at the fault's resonance frequency.
    [0144] u and v are generalized functions that will depend on the tested winding. In this way, there are two different surfaces: A surface for resonance frequencies (17) from previous tests with faults in different positions, that is, in different turn number and fault resistance, obtained from the frequency response of the phase of the winding (15). And the other surface for gains at said resonance frequency (18) from previous tests with faults in different positions and fault resistance obtained from the frequency response of the winding gain (16).
    [0146] With the resonant frequency (17) and gain at said resonant frequency, we proceed to the steps of obtaining the resonance frequency cutoff curve from a database (19) and obtaining the gain cutoff curve constant from a database (20) that propose cut curves with expressions:
    [0147] u ( n, R f ) = cte1
    [0148] v ( n, R f ) = cte2
    [0149] Where cte1 and cte2 are constant and are defined by the resonance frequency value (17) and its corresponding system gain, obtained in the test for the location of the winding ground fault (3).
    [0151] In solving the problem of location, the present invention contemplates matching the phase and gain cut curves (22) with the previous surfaces in such a way that said matching of both lines defines a cut-off point where the coordinates of the point in a plane with “XY axes” = “Rr n axes” or vice versa, these are the solutions to the earth fault diagnosis problem.
    [0153] Finally, the system and method of the invention allow the emission of information of a fault loop signal (23) and a fault resistance signal (24) by means of a fault information emission stage (25) to external devices, these being, among others, monitoring equipment or electrical protection.
    [0155] Figure 3 shows the flow chart of the method of the invention, where the steps described above are followed. First, the winding gain (12), winding phase (13) and frequency (14) signals are collected. We proceed to construct the corresponding phase transfer functions (15) and gain (16) and from the first the resonance frequency is obtained for:
    [0156] arg [H ( j2nfR) = 0
    [0157] Where H is the complex transfer function obtained in the FRA (10) measuring equipment.
    [0159] Once the resonance frequency (17) is obtained, the gain (18) is obtained from the frequency response in gain (16) for the determined value of the resonance frequency in such a way that:
    [0160] H ( j2 n fR) = A {f R)
    [0162] Once the resonance frequency (17) and its corresponding gain (18) have been obtained, the fault surface for resonance frequencies (21.a) and the fault surface for gains at frequency of resonance (21.b) corresponding to previous tests of a similar winding. We then proceed to the introduction of the parameters obtained in said database by means of the step of obtaining the cut-off curve of resonance frequency from a database (19) and the step of obtaining the cut-off curve of constant gain from a database (20) to obtain the lines that will later be cut in a 2D plane where the axes of which will be the fault resistance, Rf, and the number of the missing turn, n.
    [0164] Introducing the cut-off curve at resonance frequency (28) and the cut-off curve constant gain (29) in a 2D plane whose axes will be the fault resistance, Rf, and the number of the faulty turn, n, a matching of the cut-off curves (22) and a cut-off point is obtained between them where the solution in fault resistance (24) and number of the missing turn (23) corresponds to the severity of the fault and location of the same respectively.
    [0166] Finally, the method contemplates the emission of these parameters to other devices through a fault information emission stage (25).
    [0168] By way of a representative and non-limiting example of the invention, figure 4 shows the surfaces loaded from the database for resonance frequencies (21.a) and gain at said resonance frequencies (21.b) in three-dimensional axes. The axes of these surfaces are the fault resistance (24) and the number of turns (23), as X and Y axes and the Z-axis in frequency (30) and the fault resistance (24) and the number of turns (23) as X and Y axes and the Z-Axis in gain (31) respectively. Finally, proceeding to the cut of the surface referring to resonance frequencies (21.a) with the resonance frequency (17) of the fault and to the cut of the surface referring to the gains at resonance frequency (21.b) with its respective gain (18), a two-dimensional plane is obtained where the matching of the previous cut curves (28 and 29) intersect in turn and allow obtaining the fault loop, n, and the fault resistance, Rf.
    [0170] The system and method of the invention aims to address the disadvantages and drawbacks presented in the state of the art by proposing a way of locating ground faults in which the fault loop and the fault resistance at said point are specified in a simple way. and fast.
    权利要求:
    Claims (6)
    [1]
    1.- Ground fault location method (4) in windings (3) of electrical machines, of the type based on frequency response analysis, characterized in that it comprises -at least- the following stages:
    - inject electrical signals of variable frequency and constant amplitude through a terminal (1) of the winding (3) in the absence of the electrical machine and measure (9) in the opposite terminal (2) of said winding -at least- the gain (12 ), phase (13) and corresponding frequency (14);
    - calculating the phase (15) and gain (16) transfer functions as a function of the measurements (9) of gain (12), phase (13) and frequency (14) obtained in the previous step;
    - obtain (17) the resonance frequency (f R ) for the faulty winding; - obtaining (18) the gain A (f R ) corresponding to the resonance frequency (f R ) of the faulty winding;
    - Obtain a resonance frequency cut-off curve (19) from a database that includes fault emulations at different fault resistances (R f ) and in different turns for a typical winding, where (n) is the number of fault loop, determining the resonance frequency of the faulty winding by matching a plane parallel to the axes Rf and n, in such a way that f R = cte, obtaining a two-dimensional curve (21a) that depends exclusively on the parameters R f yn, produced by the cut between said plane (f R = cte) and the resonance frequency cut-off curve -in three dimensions- of the database;
    - Obtain a constant gain cut-off curve (20) from a database that includes values from previous fault tests at different fault resistances and in different turns for a typical winding, determining the gain for the frequency of resonance of the faulty winding by matching a plane parallel to the axes Rf and n in such a way that A ( fR) = cte, obtaining a two-dimensional curve (21b) that depends exclusively on the parameters R f and n, produced by the cut between said plane (A (f R ) = cte) and the constant gain cut-off curve -in three dimensions- of the database; - determine (23) the number of the faulty turn (n) and (24) the fault resistance (Rf) of the faulty winding of the electrical machine as the cut-off point between the resonance frequency cut-off curve and the curve constant gain cutoff; and
    - emit (25) the fault information once the signals of fault loop number (n) and fault resistance (Rf) have been collected to an external monitoring device or protection relay.
    [2]
    2. - Ground fault location method according to claim 1, in which in the step (17) indicated above, the frequency of the resonance frequency (fR) is the frequency value for which the frequency response of the phase of winding (3) is zero.
    [3]
    3. - Ground fault location method according to any of the preceding claims, in which in the step (19) indicated above, the fault emulations are functions of the spatial surface type that depend on the number of the fault loop (n) , the fault resistance (Rf) and the resonance frequency (fR).
    [4]
    4. - Ground fault location method according to any of the previous claims, in which in the step (20) indicated above, the values of previous fault tests are functions of the spatial surface type that depend on the number of missing turns (n), of the fault resistance, (Rf) and of the gain assigned to the resonance frequency, A (fR).
    [5]
    5. - Ground fault location system (4) in windings (3) of electrical machines, of the type based on frequency response analysis, provided with:
    - a device (5) for injection of voltage at variable frequency and constant amplitude between a terminal of the faulty winding and a reference to ground; - a calibrated measurement impedance (6), connected between the other terminal of the faulty winding and a ground reference (8);
    - an output meter (7) configured to measure the calibrated measurement impedance between the terminals, determine the gain (12) and phase (13) of the winding (3) as a function of the injection frequency (14) and send said information to a recipient;
    characterized in that it is also provided with a ground fault location device (11) comprising -at least- the following elements:
    - a receiver, configured to receive the frequency (14), phase (13) and gain (12) measurements obtained by the output meter (7);
    - means for constructors of phase and gain transfer functions, configured to calculate the phase and gain transfer function from the frequency (14), phase (13) and gain (12) measurements obtained by the meter (7) output;
    - means for calculating the resonance frequency and gain, configured to calculate the resonance frequency fR and the gain at said resonance frequency A (fR) of the faulty winding, from the frequency (14), phase (13) measurements and gain (12) obtained by the output meter (7);
    - a device for storing databases of previous tests of faults in a typical winding, in which faults have been emulated in different turns and with different fault resistances, configured to provide the turn number (n) of the fault to ground from resonant frequency fR and gain A (fR) for said resonant frequency;
    - cutoff curve calculating means, configured to calculate a cutoff curve of resonance frequency and a cutoff curve of constant gain from the values of resonance frequency and gain of the tested winding included in the database;
    - a fault locator, configured to find the cut-off point of the curves obtained by the curve calculating means, said cut-off point being a function of the turn number (n) of the fault and the fault resistance (Rf) ; and
    - an information emitting element configured to send the loop number (n) of the fault and the fault resistance (Rf), obtained by the fault locator.
    [6]
    6.- Ground fault location system according to claim 5, wherein the databases of previous tests of fault emulations in the form of functions of the spatial surface type that depend on the number of fault turns (n), the fault resistance (Rf) and the resonance frequency (fR).
    类似技术:
    公开号 | 公开日 | 专利标题
    US9239352B2|2016-01-19|Method of measuring earth ground resistance of a pylon
    CN106569170B|2019-07-19|A kind of metering device secondary circuit detector and its detection method
    Perisse et al.2009|Robust diagnostics of stator insulation based on high frequency resonances measurements
    CN104898024B|2017-11-03|The Failure Diagnosis of Substation Ground Network method of comprehensive surface potential and magnetic induction intensity
    CN105527537A|2016-04-27|Device and method for generator rotor winding turn-to-turn insulation fault diagnosis
    CN104237770A|2014-12-24|Analog circuit fault diagnosis method
    CN106443326A|2017-02-22|Test system and method for fault locator of power distribution network
    CN105182187B|2018-02-02|Distribution feeder phase-to phase fault distance-finding method based on mapping function
    ES2848598A1|2021-08-10|SYSTEM AND METHOD OF LOCATION OF EARTH FAULTS IN WINDINGS OF ELECTRICAL MACHINES |
    CN107153146A|2017-09-12|Reactor inductance computational methods under a kind of shorted-turn fault state
    CN104515950B|2018-05-22|A kind of build-in self-test method of integrated circuit and application
    US4849690A|1989-07-18|Detection of transposition group short circuits in machine windings
    Martín et al.2020|Ground Faults Location for Synchronous Machine Poles through Frequency Response Analysis
    ES2784533A1|2020-09-28|SYSTEM AND METHOD FOR LOCATING EARTH FAULTS IN ELECTRICAL WINDINGS |
    CN108051698A|2018-05-18|Coil turn-to-turn insulation failure detection method, apparatus and system
    JP2017150838A|2017-08-31|Storage battery measurement method and measurement device
    CN106646196A|2017-05-10|On-board direct current voltage reduction chip failure analysis method
    CN104111438B|2017-03-29|A big current loop monitoring method in a kind of current transformer error testing experiment
    CN206832877U|2018-01-02|Detect device, transmitter, sensor and the automatic control system of leakage current
    CN111650539A|2020-09-11|Method, system and device for detecting operating parameters of lead and computer equipment
    CN105259474A|2016-01-20|Online fault range finding method of T-connection cable
    CN104316791A|2015-01-28|Reason analyzing and locating method for high resistance grounding fault of transmission line
    CN105182157A|2015-12-23|Neutral point multi-point grounding detection device based on high-accuracy detection current
    US10031184B2|2018-07-24|Method and system for the detection and diagnosis of faults in running electric machines
    Soualhi et al.2020|Electrical Systems 2: From Diagnosis to Prognosis
    同族专利:
    公开号 | 公开日
    ES2848598B2|2022-02-21|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    ES2784533A1|2020-04-30|2020-09-28|Univ Madrid Politecnica|SYSTEM AND METHOD FOR LOCATING EARTH FAULTS IN ELECTRICAL WINDINGS |
    法律状态:
    2021-08-10| BA2A| Patent application published|Ref document number: 2848598 Country of ref document: ES Kind code of ref document: A1 Effective date: 20210810 |
    2022-02-21| FG2A| Definitive protection|Ref document number: 2848598 Country of ref document: ES Kind code of ref document: B2 Effective date: 20220221 |
    优先权:
    申请号 | 申请日 | 专利标题
    ES202031319A|ES2848598B2|2020-12-30|2020-12-30|SYSTEM AND METHOD FOR LOCATING EARTH FAULTS IN WINDINGS OF ELECTRICAL MACHINES|ES202031319A| ES2848598B2|2020-12-30|2020-12-30|SYSTEM AND METHOD FOR LOCATING EARTH FAULTS IN WINDINGS OF ELECTRICAL MACHINES|
    [返回顶部]