25 results about "Lightning overvoltage" patented technology

The embodiment of the invention relates to the field of power systems, and provides a collaborative design scheme generation method and device for submarine cable lightning overvoltage suppression and insulation cooperation based on a particle swarm optimization algorithm, computer equipment and a storage medium, and the method comprises the steps: carrying out the initial configuration of optimization basic data of a to-be-simulated experiment, constructing to obtain a simulation environment after initialization configuration; based on the simulation environment after initialization configuration, parallel electromagnetic transient program simulation is carried out so as to construct a bidirectional coupling framework simulation model of submarine cable lightning overvoltage suppression and insulation cooperation; and based on an improved hybrid particle swarm optimization algorithm, solving the bidirectional coupling framework simulation model to generate a collaborative design scheme corresponding to the submarine cable lightning overvoltage suppression and insulation cooperation process. By adopting the method, the overvoltage level of the submarine cable system and the technical implementation effect of insulation cooperation can be improved, and the safety of the system is improved.

This invention discloses a clamping method for lightning overvoltage on overhead lines and a combined lightning protection and vibration prevention device. The method includes the following steps: based on the propagation characteristics of lightning waves in a medium, a local impedance abrupt change point is set on the overhead line to alter the propagation process of the lightning wave; wherein, the local lightning wave impedance at the local impedance abrupt change point is less than the overhead line impedance; when the lightning wave reaches the impedance abrupt change point, the voltage wave undergoes negative reflection while the current wave undergoes positive reflection, and the electric field energy of the lightning wave is converted into magnetic field energy, thereby achieving the clamping of the lightning overvoltage. This invention actively clamps lightning overvoltage through impedance transformation and achieves integrated lightning protection and vibration prevention, completely eliminating the dependence of traditional protection on low grounding resistance, effectively reducing the lightning tripping rate while eliminating spatial conflicts and mutual interference between devices.

This utility model discloses a lightning protection power cabinet for new energy applications, belonging to the field of power equipment technology. It includes an outer casing and an inner casing, with the inner casing suspended inside the outer casing. An outer door is rotatably connected to the side of the outer casing, and an inner door is located on the side of the outer door. Several nylon support blocks connect the outer and inner casings, and between the outer and inner doors. The outer and inner doors respectively cover the openings of the outer and inner casings. A connecting frame is installed inside the inner casing near its top. In this design, the outer and inner casings are suspended and separated by nylon support blocks, forming a non-conductive air layer between them. This prevents external lightning current from being directly conducted to the electrical components inside the inner casing. A surge protector is installed on the connecting frame at the top of the inner casing, near the input terminal of the electrical components. It can quickly respond to lightning overvoltages, promptly discharge surge energy, and ultimately provide lightning protection for the electrical components.

This invention discloses a transformer with a lightning protection structure, comprising: an oil tank, windings, an iron core, an integrated lightning protection cover, a grounding structure, a lightning protection conductive plate, and a layered insulation structure. The transformer features a lightning protection cover and lightning-proof protrusion electrically connected to the outer casing at the top of the oil tank, a grounding structure including a grounding base and grounding electrodes at the bottom, and a lightning protection conductive plate connecting the lightning protection cover and the grounding base internally. The plate has conductive contacts that fit against the insulating outer casing of the windings. Multiple layers of insulating sleeves and insulating spacers are provided on the outer side of the windings. This application achieves dual protection against direct and induced lightning strikes through structural optimization, shortens the lightning current conduction path for rapid voltage relief, enhances internal insulation performance, effectively prevents insulation breakdown caused by lightning overvoltage, and improves operational stability.

The invention discloses an inductive thunder protection method, device and equipment of a wind generating set and a medium, and relates to the field of wind power generation. The maximum value of the second lightning stroke magnetic field intensity corresponding to the second lightning protection area is determined by determining the maximum value of the first positive lightning stroke current, the maximum value of the first negative lightning stroke current and the maximum value of the subsequent lightning stroke current under the preset protection level, and the second lightning protection area comprises the hub internal area of the wind generating set. The induced thunder overvoltage of the wind generating set is also located in the second lightning protection area, so that the induced thunder overvoltage of the power supply line can be determined according to the self-inductance of the power supply line after the maximum value of the second lightning magnetic field intensity is determined, and finally, the lightning protection design scheme of the wind generating set is configured based on the induced thunder overvoltage. And inductive lightning protection is carried out on the wind generating set based on the lightning protection design scheme, and the lightning protection design scheme of the scheme can flexibly adapt to the wind generating sets with different voltage grades and operating environments.

This utility model discloses a repetitive damping lightning suppression line arrester, comprising: a varistor unit for introducing lightning current into the ground; an inductive suppression unit for suppressing sudden changes in lightning current; the varistor unit and the inductive suppression unit are electrically connected and grounded; and a damping suppression unit for adjusting the suppression intensity of the inductive suppression unit according to the intensity of the lightning current, the damping suppression unit being electrically connected to the inductive suppression unit. This solution improves upon the traditional surge arrester based on the nonlinear characteristics of zinc oxide varistors to achieve protection, by setting up an inductive suppression unit to suppress sudden changes in lightning current, and by combining it with a damping suppression unit to adjust the suppression intensity of the inductive suppression unit according to the intensity of the lightning current, effectively suppressing lightning impulse current and protecting power equipment from damage caused by lightning overvoltage.

The invention discloses a power distribution network lightning overvoltage simplified analysis loop and method, equipment and a medium, and belongs to the technical field of power system overvoltage protection. The loop comprises a lightning current source, a line resistor, a line inductor, a line first ground capacitor and a line second ground capacitor; one end of the lightning current source, one end of the line first ground capacitor and one end of the line resistor are all connected with the common node, the other end of the lightning current source, the other end of the line first ground capacitor and one end of the line second ground capacitor are all grounded, and the other end of the line resistor is connected with one end of the line inductor. The other end of the line inductor is connected with the other end of the second line ground capacitor; the voltage of the common node is the overvoltage of the lightning stroke point. The loop provided by the invention is clear in physical concept and simple in structure, so that a differential equation for describing a physical relationship is deduced based on the loop, an accurate time domain analytical solution expression of the overvoltage of the lightning stroke point is further provided, and a certain basis is provided for safety protection of a distribution line.

The invention provides an ultra-high voltage line lightning arrester service life prediction method and system, and the method comprises the steps: determining a lightning current amplitude interval which causes the action of a line lightning arrester based on the shielding failure lightning resistance level and the maximum shielding failure lightning current of a target power transmission line, which are obtained through calculation based on the obtained electrical parameters and geographic parameters of the target power transmission line; calculating the lightning current occurrence probability corresponding to the lightning current amplitude interval according to the lightning current amplitude probability distribution of the region where the target power transmission line is located, and calculating the lightning current occurrence probability corresponding to the lightning current amplitude interval according to the lightning area of the target power transmission line, the ground lightning density of the region and the lightning current occurrence probability; the predicted lightning stroke overvoltage action times of the lightning arrester installed on the target power transmission line every year are calculated, the electric charge quantity consumed by the lightning arrester under the single lightning stroke overvoltage action is calculated based on the current characteristics of the lightning arrester during action, and then the predicted life of the lightning arrester is calculated based on the predicted lightning stroke overvoltage action times and the electric charge quantity.

This invention discloses a method for identifying lightning overvoltage signals based on wavelet time-frequency maps and an improved CNN, relating to the field of lightning protection technology for power transmission lines. The method includes: acquiring and preprocessing lightning overvoltage waveform data to obtain three-phase time-domain signals; extracting time-frequency features from the three-phase time-domain signals based on continuous wavelet transform and generating a three-phase time-frequency map; performing deep feature mining on the three-phase time-frequency map using a parallel feature extraction network with three pre-trained ResNet branches; weighted fusion of the output features of each branch through compression and attention activation modules; and classifying and outputting the lightning overvoltage type. This invention displays the time-frequency joint distribution characteristics of the retained signal through wavelet time-frequency maps and adaptively extracts deep nonlinear features using an improved multi-channel CNN model, significantly improving the accuracy and robustness of lightning overvoltage type identification.

The invention belongs to the technical field of power systems, and particularly relates to an overvoltage suppression method based on 220kV overhead-cable line lightning overvoltage characteristics. The method comprises the steps that a 220kV overhead-cable mixed line lightning overvoltage simulation model is constructed, the model comprises a mixed line model and a lightning current model, the mixed line model is divided into an overhead line section and a cable line section, and the overhead line model is a JMarti model; the lightning current model adopts a Hardler model, and the lightning current waveform is a double-exponential wave; based on the simulation model, multiple measuring points are arranged on a cable section to collect overvoltage data of a cable core and a sheath, and an overvoltage transmission rule under a lightning stroke working condition is analyzed; aiming at rules, optimizing suppression measures, namely adjusting parameters of a cable terminal lightning arrester, optimizing a sheath protector, and adopting low-resistance grounding to reduce the grounding resistance of a tower; and verifying the effectiveness of the scheme, ensuring that conventional lightning stroke overvoltage control indexes are met, and if not, analyzing and optimizing again until reaching the standard.

This invention discloses an electromagnetic transient modeling and calculation method for the overvoltage of air gaps and conductor insulator strings in overhead lines during lightning backflashovers. Currently, it is impossible to obtain the voltage of the air gap between the conductor and ground wire at the point of impact and the voltage of the conductor insulator strings of adjacent towers at the instant of a lightning strike on an overhead line. This invention performs electromagnetic transient simulation modeling on the structural and material parameters of the overhead line, the actual structural parameters of the towers, and the lightning current. It also performs electromagnetic transient simulation modeling on the normal operation of the power system and the actual lightning fault situation. Considering different peak values ​​and wavefront times of the lightning current, the maximum value of the lightning overvoltage of the air gap between the conductor and ground wire at the point of impact and the conductor insulator strings of adjacent towers after a lightning strike is calculated using electromagnetic transient simulation software. This provides a reference for the selection of air gaps between the conductor and ground wire and the insulation coordination design for lightning current intrusion into overhead lines, and lays the foundation for the design evaluation of various line types and tower selections.

The application provides a lightning overvoltage detection method and device for a same-tower multi-circuit transmission line. First, the coupling impedance between cross lines at a cross line position in the same-tower multi-circuit transmission line, the cross line head voltage and the cross line head current are obtained. An equivalent impedance matrix of the cross line is constructed through the coupling impedance. The cross line end voltage is calculated according to the equivalent impedance matrix, the cross line head voltage and the cross line head current. Then, a cross line model is established through the equivalent impedance matrix, the cross line head voltage, the cross line head current and the cross line end voltage. A parallel line model is established for the parallel line behind the cross line. Finally, a simulation model is established through the cross line model and the parallel line model. The simulation model is simulated to calculate the lightning overvoltage of the cross line. The lightning overvoltage characteristics obtained by the application are close to the actual working conditions, and the accuracy of lightning level detection of the same-tower multi-circuit transmission line is improved.

The utility model discloses a kind of composite lightning arresters for power station belong to lightning arrester technical field, a kind of composite lightning arresters for power station, including composite outer cover, the outer end of composite outer cover is fixedly connected with insulator string, the inside of composite outer cover is sleeved with core body, the both sides of composite outer cover are equipped with end cap, and end cap is sleeved in the outside of core body;The utility model, high-temperature band is wound on electrode and resistance chip, after that, it is made into core body by injecting durometer material outside it, after that, core body is sleeved in the inside of composite outer cover, and it is vulcanized into lightning arrester body with composite outer cover, then composite outer cover and core body are fastened and installed between by nut, resistance chip in core body is inserted with aluminium spacer, so that lightning arrester when bearing multiple lightning overvoltage impact, through aluminium spacer layer by layer barrier, its resistance chip damage degree is weakened compared to before, improve lightning arrester high current impact resistance, enhance the service life of lightning arrester whole.

The invention discloses an outdoor lightning protection type transformer, and relates to the technical field of transformers, the outdoor lightning protection type transformer comprises a protection box and a base fixedly connected to the lower surface of the protection box, and by arranging the base, the protection box can be conveniently installed at a designated position; the lightning protection mechanism is used for guiding thunder and lightning of the penetrating device to the ground, the transformer is effectively protected against damage of thunder and lightning overvoltage through the lightning protection mechanism, safe and stable operation of an electric power system is ensured, and under the condition of thunderstorm weather, generated thunder and lightning possibly invade the transformer through a power transmission line, so that the transformer cannot be damaged. The lightning protection mechanism can limit the lightning overvoltage within a safety range, so that the lightning current can be quickly discharged, the overvoltage amplitude can be reduced, and the lightning current can be prevented from generating dangerous high potential on the equipment; the transformer is protected in thunderstorm weather, and the heat dissipation function is added.

The application discloses a lightning overvoltage peak value calculation method, system, device and medium, comprising: based on the finite difference time domain algorithm, the lightning electromagnetic coupling process under different ground resistivity and lightning distance is simulated, the magnetic field response quantity and the overvoltage peak value response quantity are extracted, and the correction coefficient function and the parameter function related to the ground resistivity are fitted respectively; the lightning current peak value at the time of lightning is obtained through a lightning current acquisition device; the equivalent complex depth under the non-ideal ground condition is calculated in combination with the above functions, and the equivalent complex depth, the lightning current peak value and the line electrical geometric parameters are substituted into the closed-form analytical model to quickly solve the lightning induction overvoltage peak value of the overhead line. The application effectively overcomes the problem of insufficient precision of the traditional model under the scene of high soil resistivity and long distance lightning, and takes into account the calculation efficiency and engineering practicability.

This invention discloses a method for optimizing lightning overvoltage in AC transmission lines converted to DC operation, comprising the following steps: analyzing the relevant configuration selection for long-span sections after the AC line is converted to DC operation, and determining the parameter selection range of the relevant configuration; establishing an electromagnetic transient simulation model of the DC-converted transmission line based on the determined parameter selection range of the relevant configuration; establishing a constraint model with the minimum lightning overvoltage of the transmission line in the span section as the objective function; calling the electromagnetic transient simulation model and the constraint model, and optimizing the lightning overvoltage of the long-span section line using an adaptive particle swarm optimization algorithm to obtain the minimum lightning overvoltage value of the AC transmission line converted to DC operation that meets the line insulation configuration requirements, thus filling the research gap in the changes of lightning overvoltage in transmission lines, especially in long-span sections, and the insulation coordination scheme of long-span sections after the DC conversion.

The invention discloses a distribution transformer lightning protection range determination method and device based on split-phase differential protection, equipment and a medium, and belongs to the technical field of lightning overvoltage protection of a power distribution network. The method comprises the following steps: determining the maximum arrangement distance between lightning protection points on the distribution transformer according to multiple chopping voltage withstanding values of the distribution transformer in a lightning stroke point overvoltage wave propagation range; based on the maximum arrangement distance, lightning protection points are arranged on each phase of wire of the distribution transformer, and the lightning protection points comprise lightning arresters installed on the A-phase wire and the C-phase wire and insulators installed on the B-phase wire. The insulation level is configured in a split-phase differentiation mode, lightning stroke overvoltage is actively guided to be discharged along a preset path, the line voltage is reduced to zero, and therefore the protection range when the line is struck by lightning is expanded. The lightning arresters are only installed in the A phase and the C phase, the insulator string is adopted in the B phase, the maximum arrangement distance is determined based on the line condition, and under the condition that insulation safety is guaranteed, the equipment investment and the operation and maintenance cost are reduced as much as possible.

The invention relates to the technical field of power system overvoltage protection, and discloses a ternary overvoltage grading protection device based on characteristic spectrum analysis, which comprises a signal acquisition module; the feature extraction module is used for parallel computing of feature vectors of time domain features, frequency domain features and energy features; the ternary logic judgment module obtains a judgment result according to a preset three-state criterion and a fuzzy logic algorithm; the three-state criteria comprise lightning overvoltage, operation overvoltage and resonance overvoltage; the dynamic adjustment module is used for analyzing the judgment accuracy and the action effect of the historical events through a machine learning algorithm based on the input data, and dynamically optimizing the weight coefficient of the feature vector in the feature extraction module; and the grading protection execution mechanism drives and executes protection actions. Time domain, frequency domain and energy three-dimensional feature vectors are calculated in parallel through the feature extraction module, a comprehensive decision vector is formed by adopting a feature fusion algorithm, and accurate recognition of overvoltage types is realized in combination with three-state criteria.

The invention discloses a method and a system for configuring lightning arresters based on simulation calculation of lightning intrusion waves. The method comprises the following steps: determining initial arrangement and initial key parameters of lightning arresters at an alternating current side and a direct current side; adjusting the initial key parameter and the initial arrangement based on a temporary overvoltage and a slow wavefront overvoltage, and determining a first optimization key parameter and a first optimization arrangement; adjusting the first optimization key parameter and the first optimization arrangement based on the lightning overvoltage and the steep wavefront overvoltage, and determining a second optimization key parameter and a second optimization arrangement; based on the second optimization arrangement and the second optimization key parameter, determining the matching current and the protection level of the lightning arrester; and determining a dual selection principle of the lightning arrester based on the maximum overvoltage of the insulation position determined by the second optimization arrangement and the second optimization key parameter, and configuring the lightning arrester.

The invention discloses a ground wire strain insulator capable of inhibiting induced current and preventing sparking, which belongs to the technical field of high-voltage power transmission and comprises an insulating support module, a lightning current discharge module and a safety monitoring module. One end of the insulating support module is connected with a ground wire, and the other end of the insulating support module is connected with a tower; the lightning current discharge module is connected in parallel with two ends of the insulation support module. The insulation supporting module is used for bearing mechanical tension of a ground wire and providing corresponding electrical insulation for the ground wire. The lightning current discharge module is used for conducting when lightning overvoltage on the ground wire is monitored, and discharging lightning current on the ground wire to the ground; and the safety monitoring module is used for monitoring the leakage current and temperature of the lightning current discharge module and evaluating the operation state of the lightning current discharge module, so that the problem that spark discharge is generated by a discharge gap connected in parallel at the two ends of an insulator in the prior art can be solved.

The utility model discloses an electrical equipment overvoltage waveform identification device comprising a lightning stroke overvoltage induction module, a sampling module and a calculation module, the lightning stroke overvoltage induction module is electrically connected with the sampling module and is used for monitoring the overvoltage flowing through an electrical line in real time, and the sampling module is electrically connected with the calculation module and is used for calculating the overvoltage flowing through the electrical line. The overvoltage waveform acquisition module is used for acquiring overvoltage waveforms on an electrical circuit and sending the acquired overvoltage waveforms to the calculation module for calculation, comparison and identification of overvoltage waveform types, the calculation module is electrically connected with the threshold judgment module, and the threshold judgment module is electrically connected with the sampling module. And the overvoltage waveform higher than a set threshold value is collected through the threshold value judgment module and the calculation module is awakened. According to the utility model, the lightning stroke fault type can be accurately judged according to the overvoltage waveform, so that different methods are adopted to carry out fault removal and maintenance, thereby having important significance for overvoltage protection of electrical equipment and lightning protection of electrical lines.

The utility model belongs to the technical field of electrical equipment, concretely relates to a PT cabinet arrangement structure for inhibiting 10kV motor feeder cabinet overvoltage, the utility model discloses a suitable capacity capacitor is arranged in the PT cabinet of motor feeder cabinet side and is connected into the medium voltage system bus, can when motor feeder cabinet encounters thunder overvoltage situation, through capacitor reduces the steepness of thunder invasion wave, to protect motor vertical insulation, simultaneously through the reasonable arrangement of each element in PT cabinet, its overall structure is compact, and the operation is flexible, does not occupy the other cabinet body space of medium voltage system bus, and through the setting of capacitor, voltage transformer, lightning arrester, electrified indicating lamp etc. electrical components below handcart type isolator, can when PT cabinet electrical equipment overhauls, timely isolation equipment and power supply, form the obvious visible disconnecting point, to avoid the electrified condition of overhauls, effectively guarantee the safety of staff and equipment.

The invention relates to the technical field of power transmission and distribution equipment, in particular to a lightning overvoltage protection device, which comprises a conductive part, a grounding part, a first multi-cavity arc extinguishing device and a second multi-cavity arc extinguishing device, and is characterized in that the conductive part is connected to a high-voltage end of an insulator; the grounding piece is connected to the grounding end of the insulator; the first multi-cavity arc extinguishing device is electrically connected to the conductive piece and is provided with a first end deviating from the conductive piece; the second multi-cavity arc extinguishing device is electrically connected to the grounding piece and is provided with a second end deviating from the grounding piece; the second end and the first end are oppositely arranged at intervals, and a breakdown gap is formed between the first end and the second end; according to the invention, the first multi-cavity arc extinguishing device and the second multi-cavity arc extinguishing device are in non-rigid connection; the maximum bending moment borne by the first multi-cavity arc extinguishing device and the second multi-cavity arc extinguishing device in the arc extinguishing process is far smaller than that borne by an integral multi-cavity arc extinguishing device in an existing structure, and the requirement of a high-voltage power grid is better met.

The invention discloses a PEEC-based hybrid line lightning stroke overvoltage prediction method, and belongs to the technical field of electromagnetic transient analysis of a power system, and the method comprises the steps: obtaining the structure and material parameters of a GIL-overhead line hybrid power transmission line; discretizing conductors of different structures based on a partial element equivalent circuit theory; calculating partial resistance, inductance and capacitance parameters of each cell; establishing a frequency domain system equation by using a modified node analysis method based on the parameters; obtaining a lightning current time domain waveform and constructing a frequency domain excitation source; after solving the frequency domain, converting the frequency domain response into a time domain waveform by adopting numerical inverse Laplace transformation; and calculating a voltage refraction coefficient based on the line characteristic impedance so as to evaluate the overvoltage risk at the joint. According to the method, the problem that a traditional transmission line model is insufficient in simulation precision at the wave impedance abrupt change position is solved, accurate prediction of the lightning overvoltage of the mixed line is achieved, and a reliable basis is provided for insulation cooperation and lightning protection design.

The utility model discloses an isolation type grouping grounding thunder and lightning discharge system, relates to the technical field of thunder and lightning protection, and solves the problem that electrical equipment is damaged due to ground potential counterattack during strong thunder and lightning current. According to the utility model, by introducing the isolation suppressor, electrical isolation among the working ground bar, the protection ground bar and the lightning protection ground bar is realized, and ground potential counterattack can be effectively prevented, so that sensitive equipment in a machine room is protected from being damaged by lightning overvoltage. Moreover, through the use of the isolation suppressor, the grounding resistance value does not become a key limiting factor of the lightning protection design any more. Even if the grounding resistance value is relatively high, the isolation suppressor can effectively prevent lightning current from being conducted to equipment through a grounding system, so that ground potential counterattack is avoided. Besides, the lightning protection device is further provided with a surge protection device and a load circuit breaker, comprehensive lightning protection is provided for the circuit unit of the machine room, stable operation of equipment in the machine room is effectively guaranteed, and the shutdown risk caused by lightning is reduced.