34 results about "Geomagnetically induced current" patented technology

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 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.

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 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 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 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.

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.