34 results about "Geomagnetically induced current" patented technology

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).

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.

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.

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 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.

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 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.