34 results about "Geomagnetically induced current" patented technology

A device for use in a power transmission system to sense GICs. The device may be a part of a reactance-injecting device on a power line, it may be a standalone device, or it may be a part of another type of device. The device may include a sensor to sense magnetic fields (e.g., a Hall effect sensor). The sensor may be positioned in the air gap of a magnetic core formed concentrically around the power line. The signal from the sensor may be converted to a digital signal and separately processed to determine the magnitude of the AC current and the magnitude of the DC (or quasi-DC) current. If the output signal of another A / C current sensor is available, that output signal may be used to adjust / calibrate the determined magnitude of the DC current. The sensor may communicate with other devices in a network to provide GIC information.

The present invention relates to a method for protection of power transformers and other power system components, which are vulnerable to geomagnetically induced currents, which comprises feeding from an overhead line / s or cable conductor / s one or more DC-diverter consisting of primary diverter windings and compensation windings applied on a respective magnetic core leg, which diverter is connected to critical busses, and diverting “quasi” direct current flowing on the overhead lines or cable conductors as a result of the earth surface potential gradients caused by geomagnetically induced currents, as well as a DC diverter to carry out the method.

The present invention relates to a method for protection of power transformers and other power system components, which are vulnerable to geomagnetically induced currents, which comprises feeding from an overhead line / s or cable conductor / s one or more DC-diverter consisting of primary diverter windings and compensation windings applied on a respective magnetic core leg, which diverter is connected to critical busses, and diverting “quasi” direct current flowing on the overhead lines or cable conductors as a result of the earth surface potential gradients caused by geomagnetically induced currents, as well as a DC diverter to carry out the method.

An apparatus and method for measuring geomagnetically induced currents (GIC) is disclosed. The apparatus is configured to measure GICs temporarily flowing in high-voltage, 60 Hz power transmission conductors, and includes a securing means for securing the apparatus to the power transmission conductor. The apparatus further includes a flux concentrator having a toroidal ferrite core and winding wound around the core configured to capture a magnetic field from the power transmission conductor; a hall-effect sensor assembly configured to receive the magnetic field from the flux concentrator and produce a voltage signal corresponding to the magnetic field; and an electronics module configured to receive the voltage signal from the hall-effect sensor assembly, conduct measurements, and transmit the measurements to a local access point.

The invention discloses a geomagnetic storm detection and early warning system for protecting the safe running of a power grid. The geomagnetic storm detection and early warning system for protecting the safe running of the power grid comprises a current sensor, a current signal regulating module, a data acquisition card, a computer, a driving unit, an alarm device, a protecting device and a display and storage module. The geomagnetic storm detection and early warning system for protecting the safe running of the power grid has the advantages that: 1, geomagnetic induced current can be precisely measured; 2, hardware and software are combined, so that the operation is convenient and simple; and 3, through the high-speed data computing and data processing capability of the computer, the safety of the power grid and the data storage capability can be greatly improved.

A high-voltage power transmission system is used as an extremely large antenna to extract spatiotemporal space, physical, and geological information from geomagnetically induced currents (GIC). A differential magnetometer method is used to measure GIC and involves acquiring line measurements from a first fluxgate magnetometer under a high-voltage transmission line, acquiring natural field measurements from a reference magnetometer nearby but not under the transmission line, subtracting the natural field measurements from the line measurements, and determining the GIC-related Biot-Savart field from the difference. NASA warning and alarm systems can be triggered based on determinations of GIC amplitude levels that exceed a set threshold value.

The invention discloses a method for calculating geomagnetically induced current (GIC) of a grid in a middle-low latitude region. According to the method, on the basis of a global three-dimensional magnetosphere numerical model (a PPMLR-MHD (Lagrangian version of Piecewise Parabolic Method-Magnetohydrodynamic) model), solar wind parameters observed by a satellite serve as input conditions, geomagnetic disturbance generated by current is calculated by performing integration on a magnetic layer and an ionized layer current system, the geomagnetically induced current in the ground grid is calculated, the problem that the transitional predicting method is not suitable for calculating the GIC in the middle-low latitude region is solved, and the GIC of the grid in the middle-low latitude region calculated by the method can reflect the basic characteristic of the induced current which is actually monitored and is calculated by geomagnetic disturbance. By the method, people can timely calculate the GIC of the grid in the middle-low latitude region according to the solar wind parameters observed by an upstream satellite, whether the grid is invaded by a disastrous space weather event or not is estimated, and an active prevention measure is taken to prevent serious economic and social loss.

The invention belongs to the technical field of monitoring of high-speed rail electrical systems and discloses a method and a device for monitoring geomagnetically induced current of high-speed rails. A high-speed rail geomagnetic storm damage monitoring and recording device comprises a traction main transformer and an earth box with a traction backflow collection function, a three-phase power source is connected into a traction substation, a traction backflow wire running through an earth wire, a PW protection wire and a choke transformer midpoint lead connected with two rail bars are arranged in the earth box which is an independent box structure , and the earth box is connected with an earth electrode of the traction transformer. Since interference exists in GIC (geomagnetically induced current) sampling signals, local high-frequency noise interference can be effectively eliminated by adopting a wavelet analysis method for variable-size localization analysis of time domain and frequency domain windows. The device comprises a signal acquisition sensor, a synchronous signal acquisition card and an industrial control computer. The device with a threshold alarming function is capable of sending alarm signals when monitoring quantity exceeds a threshold, so that influences of geomagnetic storm on a railway system can be known timely and conveniently. By monitoring for a period of time, direct-current magnetic bias current of the traction transformer is recorded to provide data for analysis on safety operation of a high-speed rail tractive power supply system.

An apparatus for mitigating GIC (geomagnetically induced current) effects through a fuzzy logic controlled variable resistor. Under GIC conditions (or any unbalanced fault current condition), the GIC or unbalanced fault current flows through the neutral of a power transformer. It is detected by the fuzzy logic controller, which sends a signal to a switch to open. The resistor is in the circuit and impedes the flow of current through the neutral, thereby protecting the transformer from getting overheated.

A high-speed rail traction network power supply system earth induction current monitoring method and a device. The device is installed at the connection neutral point position on the secondary side of a traction transformer and comprises a signal acquisition unit, a signal processing unit, a control unit, a data analysis unit, a data storage unit and a storage server, wherein signal acquisition unit perform signal acquisition through two ways, one way comprises a low-pass filter at 1Hz cut-off frequency, a band rejection filter and a magnetic flux gate current sensor, the other way comprises a voltage transformer and a current transformer, and the control unit transmits a signal acquisition result and an analysis result to the storage server for analysis and inquiry and can gives an alarm through an alarm unit. The problem of difficult installation of the monitoring position due to the fact that a neutral point on the high-voltage side of the transformer of a high-speed rail traction network power supply system is not grounded can be well solved, the influence on GIC monitoring of locomotive impact working current is eliminated, and the high-speed rail traction network power supply system earth induction current monitoring method and the device has the advantages of being good in anti-interference capacity, high in integration degree, low in device cost and the like.

The invention discloses a calculation method of GIC (Pipe to Soil Potential) and PSP (Geomagnetically Induced Current) of a buried oil and gas pipeline influenced by geomagnetic storm. The method comprises the following steps of: 1, establishing a LZS-DSPL model; 2, identifying an LZS-DSPL model parameter 'soil longitudinal resistance'; 3, presetting geomagnetic storm data, input pipeline and nearby environment related parameters; 4, establishing GIC and PSP matrix equations through a Kirchhoff's law loop circuit method or a node voltage method; 5, solving numerical solutions of the GIC and PSP matrix equations, and drawing GIC and PSP curves. According to the calculation method of GIC and PSP of the buried oil and gas pipeline influenced by geomagnetic storm, the difference of grounding concepts of electric systems and pipelines and the core effect of soil resistance are considered, precision of the model is improved, thus, pipeline GIC and PSP theories are more approximate to actual monitoring values, and actual pipeline systems are facilitated to perform accurate simulated analytical investigation.

The invention relates to a method for analyzing the small disturbance voltage stability of a geomagnetic storm to a power system, and the method comprises the steps: S1, building a layered earth conductivity model, and calculating a geomagnetic storm induction earth electric field; S2, calculating reactive power loss of the transformer caused by the geomagnetic induction current by using a K value method; S3, calculating the GIC-Q of the transformer substations of the multiple geomagnetic storm events under the long-time scale, and performing fitting to obtain a probability density distribution function and a cumulative probability density distribution function of the GIC-Q of each transformer substation; S4, establishing a synchronous generator, an excitation system, an asynchronous motor load and network model, and performing linearization; S5, selecting a root strongly correlated with the dynamic load equivalent asynchronization and the transformation ratio of the on-load voltage regulating transformer according to the participation factors; and S6, fitting a probability distribution function of a feature root real part, and establishing a risk evaluation index of system probability instability caused by geomagnetic storm in combination with the oscillation instability risk coefficient.

The invention discloses a geomagnetically induced current GIC prediction method for a power station. ACE satellite solar wind real-time parameters located at a sun-earth gravity balance point L1 are adopted, through a BP neural network model, the geomagnetic storm geomagnetic disturbance data can be predicted one hour in advance, then the high-risk plant station GIC calculation model is combined,the power grid high-risk plant station GIC quantity value can be rapidly predicted one hour in advance in real time, and an important reference basis can be provided for an electric power system operation scheduling and overhaul maintenance department to formulate geomagnetic storm disaster prevention and reduction strategies.

A device for mitigation Geomagnetic Induce Currents in the power distribution network is described. It may be connected to the neutral of a star-connected three-phase transformer of the power distribution system to ground without compromising its basic insulation, operation or integrity of the system. It requires a circuit having a surge arrester resistor having an adaptive nonlinear negative volt-ampere which is inserted from the transformer neutral to ground and a ground switch connected to the ground and also connected to the surge arrester.The device has two different current paths: whenever there is no GIC the switch remains closed and current flows from the transformer to the ground via the ground switch. Under Geomagnetic Induce Currents, the ground switch opens, allowing the induced current to flow from the transformer to the ground via the surge arrester. The device is formulated and designed according to IEEE / ANSI / NEMA recommended insulation coordination guidelines in order to sustain proper protective margins to the equipment neutral basic insulation levels (BIL, BSL).

A protective device for a transformer which is connected on the high-voltage side via supply lines to a network for transmission and distribution of electrical energy, wherein the transformer includes a neutral grounding, where each supply line is connected to ground via a grounding transformer , and where the grounding transformer includes a neutral point resistance which is lower than the neutral point resistance of the neutral grounding, such that Geomagnetically Induced Current flowing on the supply lines is diverted to ground.

The invention relates to a protective device for protecting a transformer against geomagnetically induced currents. Specifically, the invention relates to a protective device for a transformer (4), the protective device being connected on the high-voltage side via supply lines (2) to a network (12) for transmission and distribution of electrical energy, wherein the transformer (4) includes a neutral grounding (13), where each supply line (2) is connected to ground (11) via a grounding transformer (1), and where the grounding transformer (1) includes a neutral point resistance (R0GIC) which is lower than the neutral point resistance (R0sub) of the neutral grounding (13), such that Geomagnetically Induced Current (GIC) flowing on the supply lines (2) is diverted to ground (11).

An apparatus and method for measuring geomagnetically induced currents (GIC) is disclosed. The apparatus is configured to measure GICs temporarily flowing in high-voltage, 60 Hz power transmission conductors, and includes a securing means for securing the apparatus to the power transmission conductor. The apparatus further includes a flux concentrator having a toroidal ferrite core and winding wound around the core configured to capture a magnetic field from the power transmission conductor; a hall-effect sensor assembly configured to receive the magnetic field from the flux concentrator and produce a voltage signal corresponding to the magnetic field; and an electronics module configured to receive the voltage signal from the hall-effect sensor assembly, conduct measurements, and transmit the measurements to a local access point.

A novel interphase distance III segment protecting method in consideration of influence of geomagnetically induced current comprises the steps of step A. detecting Ucos[phi], wherein U represents a marked value of an interphase measured voltage at a distance protecting mounting position, [phi]u / i represents a phase angle of an interphase voltage in front of an interphase current, [phi]=[phi]u / i + (90-[phi]L), wherein [phi]L represents the positive sequence impedance angle of a protected line, if the absolute value of Ucos[phi] is larger than a first preset threshold, switching on an interphase distance III segment protecting impedance component, and otherwise entering a step B; step B, detecting whether the content of secondary harmonic of the line current is larger than a second preset threshold, if yes, switching on the interphase distance III segment protecting impedance component, and otherwise entering a step C; and a step C, in a preset delayed time, determining whether the absolute value of Ucos[phi] is smaller than or equal with the first preset threshold, if yes, interphase shortcircuit is determined, and the interphase distance III segment functions. By means of the novel interphase distance III segment protecting method in consideration of influence of geomagnetically induced current, the interphase distance cannot be affected by the geomagnetic induced current, thereby improving system stability.

The invention provides an AC / DC power grid harmonic coupling modeling method and system. The method comprises the following steps: acquiring historical data of an inductive geoelectric field when a geomagnetic storm occurs; constructing an alternating current power grid transformer harmonic source model, a direct current power grid converter transformer harmonic source model, a direct current power grid converter bridge harmonic source model, a direct current power grid harmonic network model and an alternating current power grid harmonic network model according to the induced earth electric field historical data during geomagnetic storm; and constructing an AC-DC power grid harmonic coupling model based on the AC power grid transformer harmonic source model, the DC power grid converter transformer harmonic source model, the DC power grid converter bridge harmonic source model, the DC power grid harmonic network model and the AC power grid harmonic network model. According to the method, the harmonic coupling model of the AC-DC power grid is constructed, so that the harmonic distribution of the AC-DC power grid under the influence of the geomagnetic induction current can be calculated and analyzed, and the capability of predicting the harmonic risk caused by the geomagnetic induction current of the power grid is improved.

The invention discloses a method for preventing power grids being damaged by solar magnetic storms and nuclear pulse. The method comprises the following steps that: 1, the grounding grid for a neutral point of power transmission line on the power grid side of a power plant is independent of a plant grounding grid, and keeps distance with the plant grounding grid; 2, if neutral points on two sides of the transformer of a transformer substation needs to be grounded, the grounding grids thereof keep mutually independent, and keep distance with each other. According to the method, the manner that the transformer neutral point in the current alternating current synchronous power grid is directly connected with the public grounding grid of the power plant or the transformer substation is changed to be an independently grounding manner, the metallic connection channel of geomagnetically induced current is blocked, and thereby the geomagnetically induced current is partly absorbed, and the risk of causing destruction due to that the geomagnetically induced current is concentrated in one place to release is avoided.

The invention relates to a measuring device and a method for geomagnetic induction current and pipe-to-soil potential of buried pipelines. The measuring device includes: a plurality of detective poles for the pipelines, a plurality of reference electrodes, a plurality of GPS synchronous recording devices and a data processing device, wherein, a plurality of detective poles for the pipelines and aplurality of reference electrodes are used for obtaining the instant pipe-to-soil potential at a plurality of measuring points; a plurality of GPS synchronous recording devices are used for recordingthe data of the instant pipe-to-soil potential; and the data processing device is used for obtaining the surface electric-field intensity, the pipeline parameters, the geomagnetic induction current and the pipe-to-soil potential, as well as the time distribution of the geomagnetic induction current and the pipe-to-soil potential at the identical place but different time, and the spatial distribution thereof at identical time but different places according to the data of the instant pipe-to-soil potential. The measuring device and the method of the invention can obtain the accurate geomagneticinduction current and pipe-to-soil potential as well as the time and spatial distribution thereof, and have the advantages of multifunction and high accuracy, etc.

The invention relates to a geomagnetic storm disaster prevention method for buried oil-gas pipelines. The geomagnetic storm disaster prevention method comprises the following steps: step 1, a cathodic protection device is configured in each of a gas transmission station and an oil transmission station; step 2, as for pipelines outside the gas transmission station and the oil transmission station, a set of potentiostat is configured to each of the two ends of a segment of pipeline; step 3, a decoupler is arranged; and step 4, potentiostats are not permitted to be mounted in any places except the two ends of pipeline segments. The geomagnetic storm disaster prevention method for the buried oil-gas pipelines can prevent excessively high bipolarity of PSP (Pipe to Soil Potential) on two ends of pipelines caused by geomagnetic storm, prevents the potentiostats and other equipment from being damaged by excessively high GIC (Geomagnetically Induced Current) of the pipelines, caused by geomagnetic storm, improves the geomagnetic storm disaster prevention capability of the buried oil-gas pipelines and prolongs the service life of the pipelines and related equipment.

The invention relates to a non-contact type measuring device and a non-contact type measuring method for the geomagnetic induction current (GIC) of a buried pipeline. The non-contact type measuring device for the geomagnetic induction current (GIC) of the buried pipeline comprises a composite flux gate probe, a power supply module, a signal conditioning module, a microprocessor, a storage module,a local communication module and a remote communication module. For the characteristics of the geomagnetic induction current (GIC) of a helix weld-seam pipeline, a measuring device is adopted to collect and calculate the magnetic induction intensity generated by the helix current in the helix weld-seam pipeline. In this way, the accurate measurement of the geomagnetic induction current GIC of thehelix weld-seam pipeline is realized. The invention aims at overcoming the defects existing in the prior art, and provides a current model and a GIC measuring method for the helix weld-seam pipeline.Based on the method, according to the manufacturing process of the helix weld-seam pipeline, the current flowing in the pipeline is modeled in a helix track, and the accuracy of the obtained model isimproved. The GIC obtained through measurement is closer to the actual current value, and the magnitude of the GIC in the pipeline can be reflected more truly.

The invention discloses a high-voltage power grid geomagnetically induced current modeling and evaluating method. The method comprises the following steps: measuring each element of a geomagnetic field by using an absolute observation method and a relative observation method; processing terrestrial magnetism data differences by utilizing a terrestrial magnetism data interpolation method; and calculating an induction ground electric field based on a plane wave method, constructing an equivalent circuit model of the GIC, and calculating the power grid GIC according to the equivalent circuit model of the GIC. Compared with the prior art, the method is combined with the actual electrical structure of the ground in China, the problem of evaluating the ground electric field and the GIC in the high-voltage power grid is solved, the calculation accuracy is high, the reliability is high, and the method has a good application prospect.

A high-voltage power transmission system is used as an extremely large antenna to extract spatiotemporal space, physical, and geological information from geomagnetically induced currents (GIC). A differential magnetometer method is used to measure GIC and involves acquiring line measurements from a first fluxgate magnetometer under a high-voltage transmission line, acquiring natural field measurements from a reference magnetometer nearby but not under the transmission line, subtracting the natural field measurements from the line measurements, and determining the GIC-related Biot-Savart field from the difference. NASA warning and alarm systems can be triggered based on determinations of GIC amplitude levels that exceed a set threshold value.

The invention discloses a method for calculating geomagnetically induced current (GIC) of a grid in a middle-low latitude region. According to the method, on the basis of a global three-dimensional magnetosphere numerical model (a PPMLR-MHD (Lagrangian version of Piecewise Parabolic Method-Magnetohydrodynamic) model), solar wind parameters observed by a satellite serve as input conditions, geomagnetic disturbance generated by current is calculated by performing integration on a magnetic layer and an ionized layer current system, the geomagnetically induced current in the ground grid is calculated, the problem that the transitional predicting method is not suitable for calculating the GIC in the middle-low latitude region is solved, and the GIC of the grid in the middle-low latitude region calculated by the method can reflect the basic characteristic of the induced current which is actually monitored and is calculated by geomagnetic disturbance. By the method, people can timely calculate the GIC of the grid in the middle-low latitude region according to the solar wind parameters observed by an upstream satellite, whether the grid is invaded by a disastrous space weather event or not is estimated, and an active prevention measure is taken to prevent serious economic and social loss.

The invention discloses a disaster prevention and treatment method and a device for geomagnetic disturbance, a storage medium and equipment. The method comprises the steps: simulating the line induction voltage of each node based on ground conductivity data, and calculating a geomagnetic induction current sample according to the line induction voltage; and determining a probability distribution function of the geomagnetic induction current based on each geomagnetic induction current sample; analyzing the magnetic bias data to obtain the magnetic bias current of the node; substituting each bias current into the probability distribution function to obtain each actual geomagnetic induction current; substituting each actual geomagnetic induction current into the magnetic bias treatment mathematical model to obtain a calculation result output by the magnetic bias treatment mathematical model; and adjusting the state of each governance device in the power system according to the calculation result, so that the total number of the governance devices in the open state is equal to the optimal solution shown by the calculation result, thereby preventing excessive governance devices from participating in the governance process under the condition of ensuring that the number of the governance devices participating in the governance process of the power system meets the governance requirement.

The invention discloses a method for evaluating a geomagnetic induction current reactive power disturbance effect based on an engineering algorithm, and the method comprises the steps: obtaining geomagnetic data, and determining the ground conductivity, the geomagnetic data comprising geomagnetic disturbance data observed by a geomagnetic station; establishing a ground conductivity model according to the geomagnetic data and the ground conductivity, and calculating an induced ground electric field by using the ground conductivity model; establishing a power grid equivalent model, and solving geomagnetically induced current (GIC) of nodes and branches of the power grid, the geomagnetically induced current (GIC) of the nodes and the branches including a transformer neutral point (GIC); and calculating the reactive power loss of the GIC secondary transformer according to an engineering algorithm and the transformer neutral point GIC. According to the method, the reactive power loss of the GIC secondary transformer can be accurately calculated, reactive power disturbance massively sent by power grid transformers is prevented from threatening power grid safety, and support is provided for stable operation of a power grid.