800 results about "Induced voltage" patented technology

The invention discloses a pulsed eddy current detection method and system for a thermal power pipeline with a coating layer, and relates to the technical field of pulsed eddy current nondestructive detection.The pulsed eddy current detection method comprises the steps that pulsed eddy current detection simulation and experiment are conducted under the condition of a three-dimensional simulation model and a test piece, and excitation current waveform, amplitude and frequency parameters are determined; an induced voltage signal is collected, peak values, time points and attenuation characteristics are extracted, the corresponding relation between the wall thickness, the coating layer thickness and the welding seam structure and detection signals is constructed, a parameterized database is constructed, and temperature correction is completed; and optimizing a sensor structure and a signal acquisition scheme according to a parameterized database, obtaining detection data in a pipeline operation state, completing two-dimensional imaging of wall thickness distribution and welding seam positioning, and forming detection information covering a straight pipe, an elbow and a welding seam area. According to the method, wall thickness detection and welding seam positioning of the thermal power pipeline under the conditions of a thick wall and a thick coating layer are achieved through the full-process design of test piece modeling, simulation experiment and imaging collection.

A method for testing sheath impedance in a high-voltage cable cross-bonding system. Three-phase current data and three-phase grounding circulating current data from a first cable body segment and a last cable body segment in cross-bonding units, and three-phase current data, three-phase grounding circulating current data, and three-phase induced voltage data from a cable body at a cross-bonding box are detected and collected, thereby directly calculating three-phase sheath impedance of the three cable segments and determining whether the three-phase sheath impedance is abnormal (step 5), thus determining whether the tested cross-bonding units have a defect. The present invention involves a simple operation, achieves an accurate testing result, and can achieve energized testing without an external excitation source. By performing real-time testing on the cross-bonding units and calculating the sheath impedance of the three cable segments in the cross-bonding units in real time, the states of the cross-bonding units can be determined in real time, which makes it possible to detect a cable fault immediately, thereby preventing a loss caused due to the cable fault.

The invention provides a method and a system for measuring plasma current in a quasi-ring symmetrical star simulator, and relates to the technical field of star simulators, and the method comprises the steps: determining a sensor design index according to a bootstrap current simulation calculation result, and converting the design index into an actual arrangement scheme according to an installation environment constraint; all the magnet coils are independently excited in a plasma-free state, wall eddy current interference signals generated by the magnet coils are calibrated, and thus wall eddy current calibration voltage signals are output; a sensor in an actual arrangement scheme is used for synchronously collecting a total original induced voltage signal including plasma current and wall eddy current; an integral voltage signal representing the total current is output; and compensating the integral voltage signal by using the wall eddy current calibration voltage signal, and inverting the final measurement value of the plasma current in the quasi-ring symmetric star simulator. The device and the method have the beneficial effects that the interference of a stray field on a measurement result is weakened, and a high-precision diagnostic tool is provided for the plasma physical research of the star simulator.

The invention discloses an overhead line-high voltage cable sheath lightning stroke induced voltage calculation method. At present, the voltage of a lightning stroke point, a connection point of an overhead line and a cable and a point in a well of each joint along a cable sheath cannot be obtained at the instantaneous moment of lightning stroke of the overhead line on site. According to the method, electromagnetic transient simulation modeling is carried out on actual spatial positions, structural parameters and material parameters of field overhead lines and high-voltage cables, electromagnetic transient simulation modeling is carried out on lightning currents, electromagnetic transient modeling is carried out on normal operation conditions and actual lightning stroke fault conditions of an electric power system, and after the randomness of the fault occurrence moment is considered, the electromagnetic transient simulation modeling is carried out on the actual lightning stroke fault conditions of the electric power system. And the maximum lightning stroke induced voltage value of each point along the cable sheath after lightning stroke is calculated through electromagnetic transient simulation software, so that a reference basis is provided for insulation matching design of the cable sheath of the overhead line-cable mixed line invaded by lightning current, and a foundation is laid for design evaluation of various subsequent voltage limiters and protectors.

A calibration method of the magnetic field model and a controller for electromagnetic positioning are provided. In the method, a magnetic field is established through a magnetic field transmitter; measurement data is obtained through a magnetic field sensor, where the measurement data includes the amplitude of induced voltage at multiple measurement positions in the magnetic field; and the magnetic field model is corrected according to the error between the measurement data and simulated data correction, where the magnetic field model is used to generate simulation data corresponding to multiple measurement locations. The steps of modifying the magnetic field model include: establishing one or more objective functions through the nonlinear least squares method based on the error between the measured data and the simulated data; and determining the modified magnetic field model based on one or more solutions of the objective function. Therefore, positioning accuracy can be improved.

The invention discloses a small generator, and relates to the technical field of generators. The motor comprises a shell, double-end heat dissipation ventilation holes, a permanent magnet shielding rotor and a temperature control torsion limiting protection assembly. The grooves in the periphery of the rotor and the built-in paddles construct through airflow during rotation, so that self-dispersing heat dissipation is realized; coil temperature rise triggers a triode through a thermistor to drive a protection electromagnet, torque transmission of a fluted disc friction coupling is adjusted, and continuous derating can be achieved until zero-coupling shutdown is achieved; the permanent magnet adjusting assembly rapidly cuts off magnetic field output through an iron shell-aluminum strip-permanent magnet combination and an electromagnetic locking mechanism, and it is guaranteed that no induced voltage exists in the overhaul period.

The invention provides an intelligent monitoring method for a high-voltage cable grounding box, and the method comprises the following steps: collecting the current data and voltage data of a protector grounding box, calculating the resistive current value of the protector grounding box, comparing the resistive current value of the protector grounding box with a set threshold value, and determining the current value of the protector grounding box. And fault information of the protector grounding box is accurately determined according to a comparison result. The resistive current component of the protector is calculated in real time by acquiring the induced voltage and current signals of the metal sheath and the armor layer of the high-voltage cable, so that the running state of the protector is accurately researched and judged, the breakdown frequency of the protector is counted, and when a corresponding alarm threshold value is reached, corresponding alarm information and processing measures are given, so that the safety of the protector is ensured. Real-time monitoring and comprehensive evaluation of the operation states of the high-voltage cable and the grounding box thereof are realized, and the safety and reliability of cable operation are improved.

The invention is suitable for the technical field of grounding grid defect evaluation, and provides a transient electromagnetism-based grounding grid corrosion defect evaluation method and system, and the method comprises the steps: placing a sensor of a transient electromagnetic detection device above a to-be-detected region of a grounding grid, injecting a pulse current excitation signal into a conical focusing excitation coil, and carrying out the detection of the to-be-detected region of the grounding grid; acquiring an induced voltage time sequence signal through a receiving coil; extracting at least one characteristic parameter from the induced voltage time sequence signal, wherein the characteristic parameter comprises a signal peak value, peak value time, an attenuation rate or a signal integral quantity; inputting the characteristic parameters into a preset corrosion evaluation model, and performing inversion to obtain a residual thickness value or a corrosion depth value of the grounding grid in the to-be-detected area; generating and outputting a quantitative evaluation result containing the residual thickness value or the corrosion depth value; the method can be implemented in a non-stop state of the grounding grid, and an efficient and reliable decision basis is provided for safe operation and state maintenance of a power system.

The invention belongs to the technical field of geophysical exploration, and particularly discloses a differential transient electromagnetic method device and an unexploded ordnance detection method thereof.The differential transient electromagnetic method device is characterized in that a transmitter injects emission current into an emission loop, and the emission loop generates a primary field excitation signal; the underground anomalous body target generates a secondary field excitation signal under the action of the primary field excitation signal; the receiving coil assembly is based on the structure of a differential coil, synchronously counteracts a primary field excitation signal and a uniform background signal in an induced voltage, and expands a local asymmetric differential signal generated by an underground anomalous body target; and the receiver carries out time sequence analysis on the local asymmetric differential signals and extracts differential signal features so as to realize positioning and identification of an underground anomalous body target. The device is suitable for detection of shallow-buried small bodies such as UXO, the overall arrangement range of the device is small, and rapid arrangement and mobile observation in the field are facilitated.

The invention discloses a head space positioning method, device and system based on electrical impedance tomography, and the method comprises the steps: constructing a corresponding three-dimensional model according to the basic parameters of a flexible electrode cap, and carrying out the finite element meshing, and obtaining a three-dimensional mesh model; performing electric field distribution calculation on sampling points of the three-dimensional grid model according to a preset calculation rule to obtain corresponding touch electrode response information; generating a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap according to the touch electrode response information; performing projection matching according to the initial voltage data of the electrode pair and the sensitive field matrix to obtain projection matching information; and performing model training according to the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a voltage feature-space coordinate mapping relation, and analyzing the induced voltage data of the electrode pair to obtain corresponding target coordinate information. According to the method, the voltage change of the flexible electrode cap is obtained and analyzed to obtain the coordinate information, and the positioning accuracy and stability are improved.

The present invention discloses a wireless ultrasonic measurement system and a construction method thereof, wherein the measurement system includes a sensing module and a detection module; the sensing module includes a piezoelectric layer on the surface of the detection object, a first lead-out electrode structure, a first grounding electrode structure, a first insulating plate, and a sensing coil; the first insulating plate is provided with a first opening; the first lead-out electrode structure includes a first lead-out electrode on the top of the piezoelectric layer and a second lead-out electrode in the first opening; the first grounding electrode structure includes a first grounding electrode and a second grounding electrode; the second lead-out electrode and the second grounding electrode are respectively connected to the first lead-out electrode and the first grounding electrode; the sensing coil is provided at the top of the first insulating plate. The detection system of the present invention uses an insulating plate to isolate the sensing coil away from the surface of the detection object, which is conducive to the sensing coil generating a non-zero induced voltage U ind , thereby enhancing the signal of the receiving coil, and realizing contactless ultrasonic signal reception with a receiving distance of up to 20mm.

The invention belongs to the field of sensors and signal processing, and particularly relates to a wavelet kernel scale sensitivity oriented abrasive particle induced voltage signal noise reduction method, which comprises the following steps: acquiring an abrasive particle induced voltage signal, and carrying out harmonic elimination on the abrasive particle induced voltage signal to obtain a preprocessed signal; constructing a wavelet kernel function, and calculating the wavelet kernel function and the preprocessed signal to obtain a kernel scale guiding spectrum; constructing a sparse joint noise reduction model based on the kernel scale guiding spectrum; processing the sparse joint noise reduction model to obtain a convex optimization objective function; solving the convex optimization objective function by combining a self-adaptive step gradient descent method and a self-adaptive iterative shrinkage threshold method to obtain a weight vector representing the distribution of the abrasive particle characteristic signals; carrying out binarization processing on the weight vector representing the distribution of the abrasive particle characteristic signals to obtain a characteristic indication vector; carrying out Hadamard product on the feature indication vector and the preprocessed signal, and then carrying out low-pass filtering to obtain a noise reduction signal; according to the method, the abrasive particle characteristic signals can be self-adaptively subjected to non-destructive enhancement and noise reduction processing in a strong interference environment.

A power transmission tower grounding resistance non-contact measurement method based on the electromagnetic coupling principle comprises the following steps that transmitting and receiving electromagnetic coupling coils are arranged around an iron tower grounding body, and geometric calibration and spatial positioning of a measurement area are completed by combining grounding grid structure parameters and soil conduction characteristics; injecting a high-frequency alternating-current excitation signal into the transmitting coil, and synchronously acquiring the amplitude and phase response of the induced voltage at a receiving coil end; carrying out filtering processing on the induction signal by adopting a time-frequency analysis and phase decoupling algorithm, and solving a function relationship between electromagnetic response and grounding impedance by combining a coupling equivalent model; based on experimental calibration data and scene parameters, a nonlinear mapping model of induction response and grounding resistance is constructed, and real-time inversion calculation is carried out by combining a solving result obtained in the third step. According to the invention, the real-time accurate measurement of the grounding resistance under the conditions of no power failure and no wire breakage is realized, and the safety, the operation convenience and the anti-interference capability in a complex environment in the measurement process are obviously improved.

The invention discloses a zero-voltage turn-on circuit and a zero-voltage turn-on method of a switching tube in a switching power supply, and belongs to the technical field of circuits. In a critical conduction mode, when a low-side power tube is turned off, the rising edge zero-voltage starting circuit compares a switch node voltage with an input voltage or compares the switch node voltage with an output voltage under the control of a low-side gate driving voltage, outputs a high level to a high-side gate driving end when the switch node voltage is equal to the input voltage or the output voltage, and outputs a low level to a low-side gate driving end when the high level is equal to the output voltage. A high-side power tube is controlled through a high level to realize zero-voltage starting; in a critical conduction mode, when the high-side power tube is turned off, the falling-edge zero-voltage starting circuit compares an induced voltage with a pull-up resistor voltage under the control of a high-side gate driving voltage, outputs a high level to a low-side gate driving end when the induced voltage is equal to the pull-up resistor voltage, and controls the low-side power tube to realize zero-voltage starting through the high level. The induced voltage is equal to the sum of the pull-up resistor voltage and the switch node voltage. According to the invention, the transmission delay can be reduced.

The present invention discloses a superconducting motor quench detection method and apparatus based on rotational symmetry of a motor, belonging to the technical field of superconducting motor quench detection. The method includes: acquiring terminal voltages of each group of superconducting magnets in a superconducting motor, where the superconducting motor is pre-divided into at least two unit motors by using the rotational symmetry of the motor, and superconducting magnets located at corresponding positions are selected from the at least two unit motors as a group of superconducting magnets; calculating an absolute value of a terminal voltage difference of each group of superconducting magnets; and judging whether the absolute value exceeds a preset threshold, and if the absolute value exceeds the preset threshold, determining that the superconducting magnets are in a quench state. According to the present invention, induced voltages coupled by the terminal voltages of superconducting magnets are eliminated.

A charging device includes: a power transmission coil configured to transmit electric power to a terminal device; a position detection coil that includes a plurality of coils, and is configured to detect a position of a power reception coil of the terminal device; a foreign substance detection coil that includes a plurality of coils corresponding to the plurality of coils of the position detection coil; and a processor configured to supply electric power to a first coil among the plurality of coils of the foreign substance detection coil in a state in which the terminal device is not placed on a placement part, to determine that a conductive foreign substance is present on the placement part in a case in which a variation amount of induced voltage generated in the position detection coil is equal to or larger than a predetermined threshold.

The invention relates to a shaft grounding device for deriving an inductively generated voltage, current or charge from a first machine element (5), preferably a shaft, into a second machine element (1), having a shaft grounding element (4, 50) for discharging, according to the invention, the shaft grounding element (4, 50) is a component separated from a starting material, preferably a continuous article, said component being penetrated by channels (16) in the longitudinal direction thereof or being provided with perforations and / or surface structures and / or surface textures at least on the contact surface thereof with the first machine element. The invention also relates to a method for manufacturing the shaft grounding device.

Common mode voltage discharge shields are disposed over end turns of stator windings for a three phase electric traction motor within an electric vehicle. The common mode voltage discharge shields are capacitively coupled to the end turns to a ground strap, providing a low impedance path for common mode voltages accumulating at a neutral for electric traction motor as a result of high frequency switching of the motor drive voltage to produce desired torque. An insulating layer separates the common mode voltage discharge shields from the end turns. Accumulation of the common mode voltage in excess of a bearing breakdown voltage, and the associated potential for discharge through bearings between the stator and rotor and electrical discharge machining, is reduced or eliminated.

The invention relates to a charging method of an electrostatic collection board, which comprises the following steps that the electrostatic collection board comprises an inner layer board and an outer layer board, the inner layer board and the outer layer board are both metal plates, the inner layer board and the outer layer board form a capacitor, the outer layer board is electrically connected with a relay, the relay is respectively connected with a + / -1000V charging circuit, the outer layer board is provided with a conductive carrier, and the conductive carrier is connected with the outer layer board. The conductive carrier is used for collecting electrostatic charges; the inner layer plate is electrically connected with the active detection circuit; the outer layer plate is charged through the charging circuit, and the on-off of a circuit between the charging circuit and the outer layer plate is switched through the relay; meanwhile, induced charges are generated on the inner layer plate, induced voltage is generated, and the induced voltage is actual voltage. According to the scheme that the outer layer plate of the electrostatic collection plate is charged and the active detection circuit is connected to the inner layer plate, the charging voltage on the outer layer plate can be more accurate, the detection result of the decay time can be more accurate, and the collected static electricity can be used for charging equipment or providing electrostatic protection.

The invention discloses a tunnel cable grounding ring current intelligent detection and analysis system and method, and relates to the technical field of intelligent detection, and the method comprises the following steps: collecting the current of cable metal sheath grounding ring current, sheath induction voltage, equipment temperature and tunnel humidity through a sensor; analyzing and processing the collected data to obtain comprehensive detection parameters; setting a threshold value, comparing and analyzing the obtained detection data, and judging whether an abnormal condition occurs or not; according to the generated instruction, carrying out early warning and abnormity prompting on the detected abnormal condition; according to analysis and detection of different parameters, the specific types of abnormalities can be judged, the safety detection mode is triggered when it is detected that only the safety evaluation index is abnormal, whether the numerical calculation process is abnormal or not is analyzed, the numerical abnormality situation caused by calculation abnormality can be eliminated, and the safety of the numerical calculation process is improved. Detection errors of abnormal conditions of the equipment are reduced, and the problem that the false alarm rate is high in the detection process is solved.

The invention discloses a silicon carbide MOSFET parallel current sharing system and method for a pulse power supply, and belongs to the technical field of SiC MOSFET parallel current sharing, the system comprises a main power circuit connected with a plurality of SiC MOSFETs in parallel and an active driving circuit, when the SiC MOSFETs are turned on, a source inductor generates an induced voltage in direct proportion to the current rising rate, and when the SiC MOSFETs are turned on, the active driving circuit drives the main power circuit to rotate; current sharing when a plurality of SiC MOSFETs are connected in parallel is realized through an in-phase amplification circuit used for detecting and amplifying an induced voltage, a differential amplification circuit used for detecting and comparing an induced voltage value, and a proportional current source circuit is controlled to extract a SiC MOSFET gate drive current. By adopting the method, the unbalanced current can be suppressed, the balance of the current flowing through each branch of the parallel SiC MOSFETs is ensured, the SiC MOSFET device in the high-voltage pulse power supply is effectively protected, and the working reliability of the circuit is improved.

The invention relates to the technical field of power system operation and maintenance, in particular to an intelligent line shaking insulation nuclear phase test system and a test method thereof.An insulation resistance test module adopts a self-adaptive algorithm, the influence of environment temperature and humidity on a test result can be eliminated, and the insulation resistance measurement precision is remarkably improved; a dynamic grounding technology: the induced voltage suppression module adjusts a grounding state and a compensation voltage in real time through the dynamic grounding technology and a voltage compensation algorithm to ensure that a test result is not interfered by the induced voltage; a test neutral period and a quick access technology are optimized: the system can quickly complete access and test in a neutral period from grounding disconnection of a to-be-tested line to equipment access test, and damage to equipment caused by secondary rise of induced voltage is avoided; and real-time monitoring and adjustment: in the test neutral period, the system monitors the line induction voltage in real time, and dynamically adjusts the grounding state and the compensation voltage according to the monitoring result to ensure the equipment safety.

The invention relates to a method for positioning a vehicle (2), having a mobile inductive charging apparatus (1a), in a defined position with respect to a stationary inductive charging apparatus (1b), wherein a positioning signal generated in one of the two inductive charging apparatuses (1a, 1b) induces at least one voltage signal (13a, 13b) in the other of the two inductive charging apparatuses (1a, 1b), a relative distance between the mobile inductive charging apparatus (1a) and the stationary inductive charging apparatus (1b) is approximated from the induced voltage signal (13a, 13b), and a directional deviation of the vehicle from a target direction in relation to the stationary inductive charging apparatus is ascertained using a parking space detection sensor.

The invention relates to a metal component defect depth detection system and method based on sweep frequency pulsed eddy current. The system comprises a pulse eddy current probe module, a pulse signal excitation module, a current amplification module, a voltage amplification module, a band-pass filtering module and a signal acquisition module. The pulsed eddy current probe module comprises an excitation probe and a receiving probe which are respectively used for transmitting excitation signal pulsed eddy current and receiving sampling data; the pulse signal excitation module is connected with the upper computer module and the current amplification module, and is used for receiving the control command and exciting pulse signal current to control probe detection; the current amplification module is used for amplifying the pulse current; the voltage amplification module is connected with the receiving probe and the band-pass filtering module and is used for amplifying the induced voltage; the band-pass filtering module is used for frequency screening; and the signal acquisition module is responsible for performing format conversion on the sampling data and uploading the sampling data to an upper computer. The system can realize excitation and signal acquisition for different depth areas, and accurately determine the characteristic frequency of defect depth.

A control system is provided for a power conversion system having a power converter that controls a virtual synchronous generator simulating a synchronous generator and interconnected to a power grid. The control system has a virtual synchronous impedance compensation block inputting an output current detection value of the power converter and a set voltage amplitude command value, simulating a voltage drop due to a virtual synchronous impedance, and calculating an output voltage command value and an internal induced voltage according to the simulated voltage drop; a virtual synchronous generator model determining an angular frequency simulating the synchronous generator; and a PCS output voltage control unit performing control so that an output voltage of the power conversion system coincides with the output voltage command value calculated by the virtual synchronous impedance compensation block.

The invention discloses a wireless power supply type aircraft tire temperature and pressure sensor, and belongs to the field of aircraft wheel tire pressure monitoring. The sensor comprises a shell, one end of the shell is provided with a pressure probe, and the other end is provided with an energy receiving-transmitting module. An acquisition and transmission circuit board is arranged in the pressure probe; and an antenna is arranged in the energy receiving and transmitting module. The pressure probe is used for collecting temperature and pressure information in an aircraft tire and transmitting the information to the collecting and transmitting circuit board; the collecting and transmitting circuit board is used for processing the temperature and pressure information, converting the temperature and pressure information into temperature and pressure radio frequency signals and transmitting the signals to the energy receiving and transmitting module; and the energy receiving and transmitting module is used for performing electromagnetic induction with the handheld terminal to generate induced voltage, supplying power to the pressure probe and the collecting and transmitting circuit board, and wirelessly transmitting a temperature and pressure radio frequency signal to the handheld terminal through an internal antenna of the energy receiving and transmitting module. The sensor is fixed at a corresponding interface of the airplane wheel and does not need to be disassembled in the using process, and airplane wheel pressure and temperature monitoring can be carried out on the ground through a handheld terminal.

The invention relates to the technical field of high-precision positioning, in particular to a high-precision six-degree-of-freedom magnetic positioning system and method, and the method comprises the steps: generating a three-dimensional low-frequency magnetic induction field with a preset frequency in a space through a three-axis orthogonal transmitting coil; detecting the three-dimensional low-frequency magnetic induction field through a three-axis orthogonal receiving coil to obtain an induced voltage signal; transmitting the digitized induced voltage signal to a control layer; in the control layer, the position and attitude of the receiver are estimated in real time by using a joint estimation algorithm fusing error state extended Kalman filtering and particle swarm optimization; the error state extended Kalman filtering comprises the steps of constructing a state transition matrix F of a target carrying a receiver, and constructing a process noise covariance matrix Qk and a parameterized measurement noise covariance matrix R of the system through translation acceleration noise sigma a and rotation noise sigma omega. According to the invention, the PSO module is utilized to dynamically and adaptively adjust the key parameters of the ESKF, and high-precision positioning and low-delay response are realized.

The invention provides a non-isolated LED power supply minuteness-removing turn-off circuit, which comprises a second power supply processing module, a minuteness-removing turn-off module and an LED lamp module, and is characterized in that the second power supply processing module is used for converting a high-voltage direct-current power supply into an LED lamp module working power supply; the micro-brightness removal turn-off module is arranged between the output end of the second power supply processing module and the LED lamp module and comprises a direct-current impedance conversion unit, an alternating-current impedance conversion unit and a switching tube, and the switching tube is arranged on a direct-current loop; and the control unit of the second power supply processing module reduces the DC voltage and the non-isolated AC induced voltage to be below the set voltage through the switching signal and the DC impedance conversion unit and the combined action of the switching signal and the AC impedance conversion unit, thereby realizing the minuteness-removing turn-off of the LED lamp module. According to the invention, contactless switch control can be realized, circuit loss is reduced, and working noise is reduced.

The invention discloses a method for measuring and calculating parameters of a same-tower double-circuit alternating-current transmission line under high induced voltage. The method comprises the following steps: dividing the same-tower double-circuit transmission line into three groups of wiring modes; measuring the short-circuit impedance in each wiring mode and the line impedance in a mode that the tail end of the line is grounded through impedance; calculating the characteristic impedance and the propagation coefficient in the corresponding wiring mode by using the impedance measurement result of the line through impedance grounding and the line short-circuit impedance measurement result in each wiring mode, and further calculating the distribution impedance and the distribution admittance in the corresponding mode; and finally, calculating the resistance, inductance and ground capacitance of each phase lead of the same-tower double-circuit line, the inter-phase coupling capacitance and inter-phase coupling inductance of the single-circuit line, and the coupling capacitance and coupling inductance between each phase lead of the double-circuit line through the distributed impedance and distributed admittance in each wiring mode and simultaneous equations. Through the method, the induced voltage on the measured circuit can be effectively reduced, and meanwhile accurate measurement can be achieved.

According to the multi-ring sensor for transformer substation partial discharge detection and positioning and the positioning method, a multi-ring sensor structure is formed by arranging a first magnetic ring and a second magnetic ring which are embedded with each other, are vertically placed and form an included angle of 90 degrees, and whether a discharge source exists or not is judged by measuring the induced voltage of the sensor; a measurement azimuth angle and a calculation result azimuth angle are obtained according to a positioning formula calculation result of a plurality of multi-ring sensors, the specific position of the area where the discharge source is located is obtained, re-confirmation is conducted by checking whether discharge equipment exists or not, and finally a positioning result is output. According to the invention, the acquisition of partial discharge signals can be realized, the positioning of the discharge signals can be realized, the reliability of the detection signals is improved by calculating the detection signal-to-noise ratio in real time, the loss of weak discharge signals is avoided, and the positioning accuracy is improved by analyzing and judging the positioning result. According to the invention, effective detection of partial discharge weak signals in a complex environment of industrial and mining enterprises can be met, and sudden insulation faults of equipment are avoided.