206 results about "Lightning overvoltage" patented technology

PCT No. PCT/RU96/00251 Sec. 371 Date May 18, 1998 Sec. 102(e) Date May 18, 1998 PCT Filed Sep. 5, 1996 PCT Pub. No. WO97/19456 PCT Pub. Date May 29, 1997An electric power transmission line with protection devices against lightening overvoltages in the form of a lighting arrester with a surface discharge. Having a relatively long discharge path, the impulse lightening flashover does not lap over a power arc of operational frequency and, after passing of the lightening overvoltage impulse current, the line will continue a trouble-free operation without being disconnected. Simple and reliable arrester designs are disclosed among which are fittings with dielectric covers and insulators, integrating their direct functions with the lightening arrester's functions.

The invention relates to a lightning strike positioning and inversion method of a power transmission line and belongs to the technical field of high-voltage experimenting equipment and measuring. The method includes by inquiring data monitored by an online lightning current monitoring system, acquiring waveform parameters of lightning current, striking a pole tower, after being shunted through the pole tower and the power transmission line; by inquiring data monitored by a lightning positioning system, acquiring lightning strike time, lightning strike area, lightning current amplitude and lightning return strike time data; combining a theory relationship table and a theory curve and taking error of the lightning positioning system into consideration to acquire position range of a lightning strike point, and inversing feature parameters of lightning current waveform through simulating calculation. The lightning strike positioning and lightning current inversion method is high in positioning accuracy and beneficial to quick finding and repairing of line lightning strike damage, lightning strike fault finding and repairing time of the power transmission line is saved, real lightning current waveform can be restored, a basis is provided for scientific studying of lightning causes and lightning current features, and data are provided for studying of lightning protection measures and lightning overvoltage protection.

The invention discloses a distribution line lightning protection grade evaluation method, which comprises the following steps: S1, collecting distribution line electrical and structural parameters, and establishing a line parameter database; S2, carrying out statistical analysis on the actual lightning data of the distribution line region, and establishing a ground lightning density statistical model and a lightning current amplitude probability distribution function fitting model; S3, establishing a distribution line lightning overvoltage accurate simulation analysis model based on an electromagnetic transient numerical simulation program PSCAD/EMTDC; S4, simulating and calculating the lightning resistance level and the lightning trip-out rate of the distribution line under different linestructures, lightning data and landforms; and S5, arranging the simulation data, establishing a distribution line lightning protection grade evaluation mathematical model, and evaluating the distribution line lightning protection grade. On the basis of index values such as power distribution line parameters and lightning positioning system data, the lightning protection level of each base tower can be directly obtained according to the calculation model, and the effectiveness and scientificity of power distribution line lightning protection level evaluation are improved.

The invention discloses an insulative matching method for an intelligent power distribution system based on a flexible direct current. The topological structure, the mode of operation and the mode of malfunctions of the intelligent power distribution system based on the flexible direct current are comprehensively analyzed by the following steps: carrying out system analysis; configuring a lightning arrestor; carrying out simulating calculation of an overvoltage; setting insulative match. On the basis, the lightning arrestor is initially configured for the system and simulating calculation of overvoltage is conducted by establishing an inner overvoltage calculation model and a lightning overvoltage calculation model of the system so as to adjust the configuration of the lightning arrestor and the accomplish insulative match of equipment of the system, so that the system cost is the minimum while the system safely and stably operates. The scheme can be used for guiding related technical staff to efficiently carrying out insulative match analysis of a flexible direct current power distribution system.

The invention discloses a lightning-proof GNSS active antenna and relates to a GNSS receiving antenna which is applicable in navigation, positioning and time and frequency standards. The problem to be solved by the invention is to provide a high-reliability GNSS active antenna which avoids using a lightning arrester, effectively prevents damages caused by lightning stroke and has a lightning-proof capability meeting the requirements of communication industrial standards of 'Specifications for Engineering Design of Lightning Over-Voltage Protection for Communication Bureaus(Stations )' YD/T5098-2001. The lightning-proof GNSS active antenna is characterized in that: a GNSS passive antenna, a GNSS low noise amplification module, a radio-frequency cable, a lightning-protection module and a bolt-fixed sealed type needle radio frequency connector are connected in turn and accommodated in a sealed shell which consists of a radar cover and a mounting chassis; and the modularized and layered structure design is adopted, so that a production process is simplified, the production efficiency is improved and the production cost is reduced. The lightning-proof GNSS active antenna effectively prevents the active antenna being damaged by the lightning stroke, avoids using the lightning arrester, saves the system cost and simplifies the project installation.

The invention relates to an overvoltage online monitoring device based on a dual time base sampling technology, which comprises a resistance-capacitance high-voltage sensor. The signal output end of the resistance-capacitance high-voltage sensor is connected with the input end of a dual protective circuit of a signal-conditioning unit by a double-shielding layer coaxial cable. The photoelectric isolation output end of the signal-conditioning unit is connected with the input end of a photoelectric isolation module of a signal isolation unit. The output end of the photoelectric isolation module is connected with the Ethernet port of an industrial control computer. The output end of an isolation power supply of the signal isolation unit is connected with the power supply input end of the signal-conditioning unit. The signal-conditioning unit internally adopts dual time base data acquisition module redundancy for the collection of an overvoltage signal waveform to not only suitable for monitoring an overvoltage of a power system, but also suitable for monitoring an external overvoltage of the power system, particularly have predominant effect on the lighting overvoltage and improve the accuracy and the stability of overvoltage online monitoring.

The invention discloses an unrestrictive expected operation life assessment method for a distribution network lightning arrester under a given confidence level. The method comprises the following steps of: 1, monitoring the lightning overvoltage amplitudes at the installation position of the lightning arrester in one year, and counting the amplitude distribution; 2, calculating the statistical distribution of lightning impact discharge capacity resource consumption of the lightning arrester in one year; and 3, calculating the unrestrictive/restrictive lightning overvoltage expected life of the lightning arrester under the given confidence level. According to the method, the lightning overvoltage serving as a decisive factor of the service life of the lightning arrester for a distribution network is analyzed, a route and a method for calculating lightning discharge capacity resource of the lightning arrester for the distribution network and one-time lightning arrester lightning discharge capacity resource consumed by overhead circuit overvoltage due to lightning are further introduced, and finally, the expected operation life of the lightning arrester for the distribution network is calculated by adopting simplified parameters and the method.

The present invention discloses a differentiation lightning protection method of an urban area 10KV distribution line. The differentiation lightning protection method of urban area 10KV distribution line comprises: selecting a 10KV distributing line to be included in a lightning positioning system, lightning arresters on typical urban area 10KV distribution lines being all provided with discharge counters; obtaining electric parameters of the typical urban area 10KV distribution lines, the lightning parameters of the line areas and building information surrounding the lines; performing a lightning strike risk assessment of the typical urban area 10KV distribution lines; checking the motion conditions of the discharge counters after thunderstorm every time, and obtaining properties of lightning overvoltages to determine a finally adopted differentiation lightning protection measure; and determining a lightning protection measure. According to the invention, the lightning positioning system and the discharge counter are applied to the distribution lines, corresponding precautionary measures are pointedly made out, and accidents of damaging distribution lines and electrical equipment caused by frequent occurrence of overvoltage are avoided. Moreover, the differentiation lightning protection method of an urban area 10KV distribution line may pointedly perform 10KV distribution line differentiation lightning protection according to economical, obstructive and guiding differentiation lightning protection principles.

The invention relates to an overvoltage protection method and overvoltage protection devices of modular multi-level converters. The overvoltage protection method comprises the following steps of arranging the overvoltage protection devices of the modular multi-level converters between alternating current ends of the modular multi-level converters and the ground, or between direct current ends and the ground, or between the alternating current ends, or between the direct current ends or more than one of the positions at the same time, setting operation voltage parameters of lightning arresters, setting operation voltages of discharging circuits and setting delay operation time of the discharging circuits, wherein each overvoltage protection device comprises the discharging circuit, a voltage-sharing damping circuit and the lightning arrester, the operation voltage parameters of the lightning arresters comprise reference voltages, operation overvoltage protection levels, lightning overvoltage protection levels and steep wave overvoltage protection levels, and the operation voltages of the discharging circuits are set according to expected invasion power frequency overvoltage levels. By means of the overvoltage protection method and the overvoltage protection devices of the modular multi-level converters, economical efficiency and reliability of the modular multi-level converters are improved.

The invention discloses a method and device for detecting overvoltage of a circuit breaker under multiple lightning strokes, and the method comprises the steps of collecting the data of equipment in astation, building a lightning invasion wave simulation model of a line-transformer substation in an electromagnetic transient program according to the data of the equipment in the station, the circuit breaker being simulated through a Cassie arc model; and acquiring lightning overvoltage of the circuit breaker in real time by adopting a multiple lightning counterattack tower and a shielding failure wire in the simulation model. According to the invention, the problems that the overvoltage of the circuit breaker under multiple lightning strokes is difficult to simulate and the simulation result is inaccurate are solved.

The invention discloses a lightning stroke discharge comprehensive analysis method, device and terminal equipment and a storage medium. The method comprises a step of acquiring the relative time relation of an optical image, an optical radiation signal, an electric field signal, a magnetic field signal, a thunder signal and a photographing start signal in a lightning stroke discharge process froma fixed-point near-area observation system and lightning electromagnetic wave characteristic parameters from a wide-area lightning monitoring system, a step of analyzing a lead development characteristic, a relative integral brightness and an M component characteristic of the lightning stroke discharge to obtain an optical signal characteristic according to the relative time relation of the optical radiation signal, the optical image and the photographing start signal, a step of analyzing array parameters of a thunder sound source positioning device, thunder identification and thunder sound source positioning according to the thunder signal to obtain acoustic signal characteristics, and a step of analyzing the lightning electromagnetic wave characteristic parameters to obtain lightning discharge engineering parameters. The change rules of electricity, magnet, light, sound and other physical parameters in the lightning discharge process can be mastered, and the calculation accuracy of the lightning overvoltage of the power grid can be effectively improved.

The invention provides a method for measuring equivalent inductance of a coupling capacitance loop under lightning over-voltage and system thereof, wherein the method comprises the following steps of: obtaining an equivalent capacitance value and an equivalent resistance value of the coupling capacitance loop on a to-be-measured transmission line; obtaining a sampling value of response current onthe coupling capacitance loop, when an amplitude of the sampling value exceeds the predetermined value, calculating an oscillation period of the response current; and calculating the equivalent inductance of the coupling capacitance loop according to the equivalent capacitance value, equivalent resistance value and the oscillation period of the response current. The method and system for measuring equivalent inductance of the coupling capacitance loop under the lightning over-voltage provided by the invention can self-diagnose coupling capacitance stray parameters of a transforming plant withthe voltage level more than 110kV under the lightning over-voltage. The response current of the coupling capacitance loop is measured by mounting a Rogowski coil current measuring device; as the Rogowski coil current measuring device does not have direct electrical connection with the current loop of the measured transmission line, the Rogowski coil current measuring device is favorable to safe and reliable operation of the transforming plant.

The invention discloses a typical power plant lightning arrester configuration and insulation coordination modeling method. The method comprises the following steps that a transient simulation programis applied to build a typical power plant simulation model conforming to the actual situation on site; in a zinc oxide lightning arrester model, zinc oxide lightning arrester model parameters are set; a rated voltage value of a lightning arrester comprises slow-front overvoltage and fast-front overvoltage; assuming that any leading-out terminal of a power plant is subjected to random lightning overvoltage attack, modeling is conducted on power plant main electrical connection, the built typical power plant simulation model runs, voltage waveforms of all reference points are observed, and insulation and system stability of a main electrical system of the power plant provided with the zinc oxide lightning arrester are verified. Accordingly, the number and positions of the power plant lightening arresters are subjected to optimization selection, the insulation level of equipment is determined according to regulation, the insulation margin is verified, and guidance is provided for insulation coordination design of the typical power plant.

The invention discloses a lightning overvoltage protection method and system for AC power input in a remote machine room, which includes a power environment monitoring system and an AC power switch; the AC power switch is connected in series between the AC input end and the AC power distribution in the remote machine room Between the input ends of the box, the control end of the AC power switch is connected to the switch control signal output end of the monitoring equipment; the monitoring center used to obtain the lightning warning information from the local meteorological department in the computer room passes through the communication transmission equipment, communication The access device sends a control instruction to the monitoring device, and the monitoring device sends an execution command to the AC power switch according to the control instruction to control the AC power switch to be turned off or on. The present invention can protect communication equipment such as power supply, monitoring, transmission, exchange, access, base station, air conditioning, lighting and other equipment in the computer room from the impact of lightning overvoltage from the AC power line through the power environment monitoring system and the isolation and insulation method.

The invention discloses a two-stage series gap lightning flashover protector capable of being replaced in an electrified mode. A high-voltage wire is connected to a wire clamp seat in a led mode, the lightning flashover protector cannot be affected by power frequency voltage or switching overvoltage at ordinary times through the air gap between a drainage rod and a discharge electrode, and therefore the service life of the lightning flashover protector is prolonged. When lightning overvoltage exists and can break through two series gaps at the same time, the effective action of the lightning flashover protector is guaranteed, the discharge path of arcs is controlled, the amplitude of the lightning overvoltage is limited, and an insulator flashover accident is avoided. Due to the fact that the whole lightning flashover protector is structurally divided into a high-voltage part and an operable part, and the high-voltage part and the operable part are isolated through a core rod, it is guaranteed that when a 10kV overhead line is operated normally and an operator detaches the lightning flashover protector, the operator cannot touch the high-voltage wire. The lightning flashover protector can be conveniently taken down and installed under the power grid electrified condition only through a tool line connector rod commonly used in an electric system.

The invention discloses a 110 kV thyristor valve type controllable lightning arrester device and a verification method. The device comprises a controlled element module and a thyristor valve switch module which are located at a low voltage end and a fixed element module located at a high voltage end; when system operation overvoltage exceeds a control voltage threshold, the thyristor valve switchmodule is conducted, the controlled element module is short connected, the residual voltage of the fixed element module is low, and the system operation overvoltage is deeply limited; under system continuous running voltage, temporary overvoltage and lightning overvoltage, the thyristor valve switch module is disconnected, and the controlled element module and the fixed element module bear the system voltage or the overvoltage together; the thyristor valve type controllable lightning arrester device can perform a static potential distribution test, motion characteristic tests under the temporary overvoltage, operation overvoltage and lightning overvoltage and residual voltage test respectively, and can effectively verify the correctness of a working principle of a controllable lightning arrester, and motion accuracy and reliability of the controllable lightning arrester under various overvoltage.

The invention provides a lightning overvoltage measuring system, which comprises a lightning overvoltage sensor, a high-speed data acquiring and processing unit and a solar power supply system, wherein the lightning overvoltage sensor is realized by adopting a high-speed capacitive voltage divider, and can be used for acquiring instantaneous voltage during lightning overvoltage through the operation of the high-speed capacitive voltage divider; the high-speed data acquiring and processing unit is used for acquiring a low-voltage signal from the lightning overvoltage sensor; the low-voltage signal is firstly subjected to analog-digital conversion through an analog-digital converter, and is buffered in a buffer; a processor is used for reading data in the buffer for processing. The solar power supply system can be used for providing energy for the lightning overvoltage measuring system without connecting a general alternating-current power grid power supply, and the influence of measuring high voltage generated by lightning on an alternating-current power grid is avoided.

The invention discloses a simulation test platform for lightning-caused breaking of an insulated wire in a 10kV distribution network. The simulation test platform includes an impulse voltage unit, a simulation tower wire unit, a power frequency current source unit and a data acquisition unit, wherein the impulse voltage unit is connected to an insulated pillar on a tower at one side through the insulated wire; the impulse voltage unit is used to provide a simulation lightning impulse voltage to the insulated wire on the tower; the power frequency current source unit is connected to an insulated pillar on a tower at the other side through a third insulated wire; the power frequency current source unit is configured to provide a set power frequency current to the insulated wire on the towerafter the impulse voltage unit generates the simulation lightning impulse voltage and after the first preset time period; and the data acquisition unit is used to collect lightning overvoltage and thewire current on the insulated wire. Through the technical solution in the simulation test platform for lightning-caused breaking of an insulated wire in a 10kV distribution network, after simulationlightning impulse voltage is broken down and insulated, a continuous power frequency current is provided for the generated arc to improve the authenticity of the lightning-caused breaking test.

The invention discloses a method of estimating lightning protection of high-voltage transmission line pole/tower grounding devices. The method includes: establishing three grounding device physical structure models of a square type, a well type and a grid type, which are distribution parameter models; subjecting the physical structure models to simulation analysis by a ground resistor considering spark effect or not considering spark effect on the basis of PSCAD/EMTDC, thus obtaining lower ground impulse resistance of a grounding which considers spark effect; when the spark effect is considered, subjecting injection point overvoltage of the physical structure models to simulation analysis to obtain lightning impulse features of the three grounding devices. Technicians can select proper grounding devices according to actual conditions by the method, so that injection point lightning overvoltage of the grounding devices can be reduced, impulse grounding resistance of the grounding devices is reduced indirectly and lightning protection of poles and towers is improved.

A lightning overvoltage monitoring system for a substation secondary system is characterized in that a low-damping series resistance-capacitance divider acquires a surge overvoltage signal, a parallel resistance-capacitance divider divides voltage of the surge overvoltage signal, voltage amplitude of surge overvoltage is lowered, part of an overvoltage division signal enters a trigger circuit for overvoltage judging, whether overvoltage signal acquisition is required or not is determined, the other part of the overvoltage division signal enters a signal processing circuit for impedance isolation and low-pass filtering, when triggered, a data acquisition card acquires an overvoltage signal output by the signal processing circuit and transmits the overvoltage signal to a background computer for overvoltage waveform statistics and analysis, action reliability of an arrestor is judged according to analysis results, maintenance for the arrestor of the substation secondary system is thus guided, and running safety and normality of the substation secondary system is ensured.

The invention provides a lightning-protection type GNSS (Global Navigation Satellite System) signal relay amplifier which is suitable for long-distance transmission of GNSS signals and is applied to a clock system for mobile communication. The invention aims at providing a high-reliability GNSS signal relay amplifier capable of avoiding the use of a lightning arrester and effectively preventing the damage caused by lightning stroke. The lightning-protection capability of the GNSS signal relay amplifier meets the requirements of YD/T5098-2011 communication bureau (station) atmospheric overvoltage protection engineering design specification of communication industry standard. The GNSS signal relay amplifier consists of a thread-fixed closed needle type radio frequency connector, a closed aluminum alloy protection shell, a box body sealing rubber ring, a lightning-protection type GNSS low-noise amplification module and a plurality of bolts and has the advantages of being simple in structure, effective in lightning protection, excellent in sealing property and convenient for construction, cost-saving and meeting the requirements of the industry lightning-protection standard.

The invention relates to a high-reliability thermal-protection piezoresistor. An overheating separation node is arranged at each of two surfaces of a resistor disc, and the positions of the nodes are selected properly, so that the current separation range of the piezoresistor is wide from several mA to 100A, the separation speed is high and is faster than that of most of existing products under large current by 10 times, the safety is good, and the firing is avoided; the piezoresistor can be used independently and also can be used as a chip of a surge protection device (SPD) for preventing lightning overvoltage, operation overvoltage and other surge overvoltage, so that the electrical and electric devices and equipment are protected; when the piezoresistor is used in a use circuit, a fuse protector or an air switch for preventing the short circuit of an upstream piezoresistor can be omitted.

The invention relates to a device for power transmission and transformation, in particular to an anti-corrosion resistance-reducing lightning protection grounding device adopting a multi-component alloy grounding body. The anti-corrosion resistance-reducing lightning protection grounding device adopting the multi-element alloy grounding body is characterized in that a core body copper rod is arranged in the alloy grounding body in a casting mode, one end of the copper rod is connected with a cable, the copper rod is in brazing connection with the cable, the other end of the cable is connected with a steel plate, and the steel plate is connected with a grounding steel belt. The alloy grounding body is formed by casting multi-element metals including magnesium, manganese, zinc and aluminum and is embedded into an electrolyte material. The copper rod is processed through a silver process. The anti-corrosion resistance-reducing lightning protection grounding device has the advantages that a cathode protection principle is adopted, the copper rod is arranged in the multi-element alloy grounding body and processed through the silver process, the anti-corrosion resistance-reducing lightning protection grounding effect is good, lightning current produced under lightning overvoltage has good current drainage effect, and a protection function is complete. The service life can reach to 50 years.

The invention provides a lightning protection method. The method comprises the steps that when an overvoltage on-line monitoring device judges that overvoltage signals in a power grid are lightning overvoltage signals through a preset lightning overvoltage model, control signals are sent to a lightning protection device. The anti-thunder device conducts lightning protection operation after receiving the control signals. The lightning protection method and system prevent lightning stroke events caused by the lightning overvoltage signals.

The invention relates to a lightning protection method of a 10kv power distribution circuit. Through applying a thunder and lightning positioning system and a counter on the power distribution circuit, under the condition that the normal safety operation of the normal power distribution circuit is not influenced, the action situation of a discharge counter is observed after the thunderstorm each time, and parameters and atlas displayed by the lightning position system are observed again, so that the thunder and lightning overvoltage properties can be judged, thus corresponding preventive measures are worked out purposefully, and the accident that the power distribution circuit and electrical equipment are frequently damaged because of overvoltage is eradicated; and the system is simple to mount, low in cost and reliable in operation.

The invention discloses a metal oxide arrester which is used for protecting an alternating current electrified railway traction power supply system, is provided with an air gap, and comprises a cross arm and an arrester body, wherein the cross arm is fixed on a pole tower shoulder support, and the arrester body is suspended and fixed on the cross arm; in addition, the arrester also comprises a high voltage electrode and a low voltage electrode, wherein the low voltage electrode is assembled at the lower end of the arrester body and is firmly electrically connected with the arrester body, the high voltage electrode is assembled on a line lead and is firmly electrically connected with the line lead, and an air gap is formed between the high voltage electrode and the low voltage electrode. When overvoltage happens to lighting, the arrester can reliably act; after the lightning passes, the arrester easily restores insulation, has good stability, basically needs no maintenance and can be used on a 27.5kV electrified railway F line suspension insulator to effectively prevent the problem of line break of a traction power supply system due to lightning strike.

The invention discloses a lightning overvoltage calculation method based on a full-wave electromagnetic transient model. The method comprises the following steps of 1, by regarding lightning current, a power transmission line, a pole tower and a pole tower grounding net as conductors, building a full-wave electromagnetic wave pause model integrating the power transmission line, the pole tower and a grounding electrode; 2, performing frequency domain and time domain conversion on lightning voltage or lightning current to obtain time domain signals of the lightning voltage or the lightning current; 3, calculating the impact response characteristic of the pole tower by using a moment method; obtaining the distribution of leakage current on the pole tower and conductor section potential; 4, obtaining voltage on a pole tower cross arm conductor according to the leakage current of each conductor section and the conductor section potential, wherein a difference value of the voltage on the pole tower transverse beam conductor and the operation voltage of the power transmission line is the voltage value. The method provided by the invention has the advantages that the lightning overvoltage calculation precision can be improved; the reliable technical support is provided for the electric power system lightning protection; the feasible lightning protection technical scheme can be favorably made.