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217 results about "Transient current" patented technology

Transient current is an oscillatory or aperiodic current that flows in a circuit for a short time following an electromagnetic disturbance as a nearby stroke of lightning or switching.

Heater fault early warning method and system based on current analysis

The invention belongs to the technical field of fault early warning, and discloses a heater fault early warning method and system based on current analysis. Comprising the steps that transient current signals of all heating wire loops in the copper bush heater are collected in real time, harmonic characteristic parameters are extracted, and a dynamic current fingerprint database and a multi-dimensional harmonic characteristic spectrum are generated respectively; dynamically calculating the contact impedance between each heating wire and the copper sleeve groove according to the dynamic current fingerprint database and the multi-dimensional harmonic characteristic spectrum; the current distribution path of each heating wire in the copper sleeve groove is restored in real time, the abnormal contact form of each heating wire is identified, the falling risk probability and falling risk strength of each heating wire are dynamically predicted by fusing the falling precursor signals of each heating wire detected in real time, and a grading early warning strategy report is generated in real time; according to the invention, fault early warning can be converted into preventive maintenance from post-maintenance, the intelligent level of operation and maintenance of the heater is improved, and the continuity and safety of production are guaranteed.
Owner:ZHEJIANG HENGDAO TECH

Method for measuring and analyzing residual magnetism characteristics of iron core

The invention discloses a method for measuring and analyzing residual magnetism characteristics of an iron core. According to the method, a to-be-detected iron core is demagnetized, preset residual magnetism is set, direct-current voltage excitation with opposite polarities, the same amplitude and the same duration is applied to a primary winding of the to-be-detected iron core, and transient current response signals are synchronously collected; two groups of current under positive / negative polarity excitation are extracted, and the residual magnetism direction is judged by comparing the change rate of the current; a curve of equivalent resistance changing along with time is calculated based on forward current and voltage, a resistance value corresponding to a characteristic inflection point moment is selected, the resistance value is substituted into a pre-established residual magnetism-equivalent resistance empirical formula to deduce the magnitude of residual magnetism, and a matched iron core residual magnetism detection and demagnetization integrated system integrates information management, residual magnetism detection, demagnetization and display modules. And closed-loop automation of detection, analysis and demagnetization is realized. According to the method, a magnetic field sensor is not needed, the residual magnetism direction and size can be synchronously obtained in a high-precision and robust mode only through port electric signals, and the method is suitable for on-site off-line or live detection.
Owner:DC OPERATION INSPECTION BRANCH OF STATE GRID HENAN ELECTRIC POWER CO

Electric energy metering error evaluation method and system of direct current charging pile, equipment and medium

PendingCN121831661AEfficiently quantify transient metrology deviationsadaptableElectrical measurementsClosed loop analysisControllability
The invention discloses an electric energy metering error evaluation method and system for a direct current charging pile, equipment and a medium, and the method comprises the steps: constructing an electric energy disturbance response function based on transient voltage and transient current, and effectively quantifying the transient metering deviation caused by measurement lag, voltage drop, current peak and other factors in the actual operation of the direct current charging pile. Error reconstruction modeling has higher dynamic adaptive capacity and physical rationality, the limitation that in the prior art, the influence of the high-variable-load working condition on metering cannot be reflected is broken through, and the accuracy and timeliness of direct-current charging pile error monitoring are greatly improved. Besides, a standard error is introduced to carry out fitting calibration on a reconstruction error and carry out energy conservation verification, thereby realizing verifiability on a physical level and controllability in engineering implementation, enhancing credibility and authority of an evaluation result, constructing a closed-loop analysis mechanism from error evaluation to metering correction and then to conservation verification, and improving reliability and reliability of the evaluation result. And the closeness and the adaptive capability of the overall error evaluation are improved.
Owner:STATE GRID HUNAN POWER SUPPLY SERVICE CENT (METROLOGY CENT) +2

IGBT parallel current sharing control circuit and method for turn-off transient current change rate detection

The invention relates to an IGBT parallel current sharing control circuit and method for turn-off transient current change rate detection, and the circuit employs a PCB Rogowski coil probe to carry out the non-contact detection of the turn-off current change rate of a parallel device, thereby accurately judging the non-current sharing characteristic of the parallel device. The problem of integrated design of a traditional detection scheme in large-current and high-power-density application is effectively solved; meanwhile, by designing a current change rate peak holding circuit, the holding time of a peak signal is remarkably prolonged, and the performance requirement on the ADC sampling rate is greatly reduced; a reset branch is additionally arranged for the peak holding circuit, and the peak output value in the last period is zeroed in the turn-on transient state by using a driving signal, so that the charge accumulation effect is effectively eliminated, and the sampling precision of the system is guaranteed; the regulation and control part of each parallel branch only needs to be additionally provided with two passive elements including the control switch and the capacitor, current sharing control can be achieved by adjusting the access time of the bypass branch, the structure is simple, cost is low, and good popularization applicability is achieved.
Owner:TIANJIN RES INST OF ELECTRIC SCI +1

Power grid protection method and device based on relay equipment, electronic equipment and medium

The invention relates to the technical field of power grid protection based on relay equipment, and discloses a power grid protection method and device based on the relay equipment, electronic equipment and a medium, and the method comprises the steps: building a power distribution network topological structure through obtaining the data and switch states of the relay equipment in real time, and precisely recognizing main protection equipment and backup protection equipment; according to the method, the transient current is calculated, the capability of capturing fault features is improved through real-time dynamic analysis, target setting parameters of the main protection device and the backup protection device are solved through a constructed preset target function, and the states of the main protection device and the backup protection device are set. The method has the advantages that the safety and reliability of a power system are improved, the limitation of a traditional relay protection constant value method in a complex and dynamic power distribution network environment is solved, efficient access of new energy is promoted, large-scale power failure risks are reduced, and the method has important application value and popularization prospects.
Owner:YUNNAN POWER GRID CO LTD PUER POWER SUPPLY BUREAU

Power distribution network-oriented electrical equipment fire risk assessment system and method

The invention provides an electrical equipment fire risk assessment system and method for a power distribution network, and relates to the technical field of fire risk assessment, and the method comprises the steps: extracting fault arc features and odd harmonic features of target electrical equipment from a current signal and a voltage signal of the target electrical equipment in the power distribution network; carrying out gradient analysis on the coupling effect of the target electrical equipment due to harmonic heating and load fluctuation thermal shock to obtain a sensitive gradient of thermal runaway generated by the target electrical equipment, and further determining a thermal stability margin of the target electrical equipment under a harmonic distortion working condition; according to the transient current impact value of the target electrical equipment in the nonlinear load fluctuation process, determining an accumulative effect coefficient of thermal aging generated by the target electrical equipment; and then performing fire risk assessment on the target electrical equipment to obtain a risk assessment index of the fire of the target electrical equipment. According to the invention, the method can achieve the evaluation of the fire risk of the electrical equipment under the complex working condition of current and voltage signal distortion caused by a nonlinear load in a power distribution network.
Owner:SHENZHEN SAIFEIQI PHOTONICS TECH CO LTD

Coal mine power grid fault positioning method and device and medium thereof

The invention relates to the technical field of power grid faults, in particular to a coal mine power grid fault positioning method, which comprises the following steps: collecting transient current traveling wave signals generated when a fault occurs; executing a first layer of PSO to adaptively find an optimal parameter combination for the VMD, and processing a transient current traveling wave signal based on MRSVD to obtain an input signal of the VMD; inputting an input signal into VMD based on the optimal parameter combination, decomposing to obtain intrinsic mode function components, calculating a kurtosis-permutation entropy index of the intrinsic mode function components, selecting the intrinsic mode function component with the highest value as an optimal mode component, extracting initial traveling wave arrival time by combining a symmetric differential energy operator, executing a second-layer PSO, and obtaining a second-layer PSO; correcting the initial traveling wave arrival time through a physical constraint optimization model, and adjusting the traveling wave velocity by adopting a self-adaptive wave velocity estimation strategy to obtain the corrected traveling wave head time and traveling wave velocity; and calculating the position of the fault point based on the corrected traveling wave head time and traveling wave velocity. According to the invention, rapid and accurate positioning of fault points is realized, and the robustness is high.
Owner:TIANDI CHANGZHOU AUTOMATION +2

Single-phase earth fault line selection method based on double-layer parameter adaptive optimization

The invention discloses a single-phase earth fault line selection method based on double-layer parameter adaptive optimization, and the method comprises the following steps: collecting three-phase current corresponding to each feeder line of a target system after the single-phase earth fault of the target system occurs, and carrying out the calculation to obtain zero-sequence transient current; inputting the zero-sequence transient current into a self-adaptive optimization decomposition model for self-adaptive decomposition to obtain an intrinsic mode component of a corresponding feeder line; extracting transient characteristics based on the intrinsic mode component and constructing a transient characteristic matrix; and inputting the transient characteristic matrix into a pre-trained optimization mechanism fault line selection model, outputting a fault posterior probability corresponding to each feeder line, and determining a fault feeder line according to the fault probability. According to the invention, double-layer parameter adaptive optimization is used for carrying out joint optimization on key parameters of a decomposition model and key parameters of a line selection model, so that effective feature extraction and reliable discrimination can still be realized under the conditions of complex zero-sequence transient current high-frequency components and unclear features caused by the access of the distributed power supply; therefore, misjudgment and missed judgment are reduced, and the fault line selection accuracy and robustness are improved.
Owner:CHINA JILIANG UNIV

Offshore wind power dc collection system single-ended protection method based on transient current rate of change

The present application relates to a kind of offshore wind power dc collection system single-end protection method based on transient current rate of change, the transient fault current of each collection line of dc collection system is calculated, the transient fault current is the difference between current value and steady-state current value before fault;The transient current rate of change of each line positive and negative is calculated;If the inter-pole unbalance voltage is greater than the first voltage threshold, then start monopolar ground fault protection process, according to the polarity and amplitude relationship of the transient current rate of change of each line positive and negative, determine fault line and fault pole;If the inter-pole measurement voltage is less than the second voltage threshold, then start bipolar short-circuit fault protection process, according to the polarity and amplitude relationship of the transient current rate of change of each line positive and negative, determine fault line and fault pole.Compared with prior art, the present application has the advantages of high accuracy, high adaptability and strong reliability.
Owner:STATE GRID SHANGHAI MUNICIPAL ELECTRIC POWER CO +1

Fault isolation and self-healing control method for multi-terminal flexible direct current power supply system

The invention discloses a fault isolation and self-healing control method for a multi-terminal flexible direct current power supply system in the field of flexible direct current power supply, and aims to solve the technical problems that a traditional multi-terminal flexible direct current system is lagged in fault positioning, low in isolation speed, not timely in self-healing response and low in power supply recovery precision. According to the method, through a closed-loop control logic of fault feature extraction, accurate positioning, rapid isolation and dynamic self-healing, a fault identification model is constructed based on collaborative features of transient current and voltage, and millisecond-level positioning of a fault section is realized in combination with a simplified fault positioning formula; an IGBT series solid-state circuit breaker is adopted to realize rapid fault isolation, a self-healing scheduling strategy of load priority and resource adaptability is introduced, and power supply is recovered through cooperative scheduling of a distributed power supply and an energy storage unit. The fault isolation time is shortened, the power supply recovery success rate is improved, the voltage recovery deviation is reduced, and the power supply reliability and the operation toughness of the multi-terminal flexible direct current power supply system are remarkably improved.
Owner:ELECTRIC POWER OF HENAN LUOYANG POWER SUPPLY

Power distribution line fault location method and system

The application provides a power distribution line fault positioning method and system. Transient current traveling wave signals of each monitoring section of a power distribution line and measurement data of a doubly-fed wind turbine are collected when a fault occurs. Equivalent inductance analysis is performed on the doubly-fed wind turbine based on the measurement data to obtain a dominant characteristic frequency band. A plurality of transient signal characteristic quantities are determined according to the dominant characteristic frequency band and the transient current traveling wave signals. The energy distribution of the transient current is determined according to all the transient signal characteristic quantities. The transient energy of each monitoring section of the power distribution line is evaluated according to the energy distribution to obtain the distribution difference of each monitoring section. When the distribution difference of any monitoring section exceeds a threshold value, the monitoring section is determined to be a fault section, and the distance of the fault point in the fault section is determined. The scheme of the application can be used to position the fault of a weak power grid power distribution line under the coupling mechanism of the transient response characteristics of the doubly-fed wind turbine and the meshed loop.
Owner:INNER MONGOLIA ELECTRIC POWER (GRP) CO LTD ALXA POWER SUPPLY BRANCH

Gallium nitride power device packaging parasitic parameter degradation monitoring method

The invention provides a gallium nitride power device packaging parasitic parameter degradation monitoring method. The method comprises the following steps: establishing a high-frequency RLC oscillation model of a gallium nitride power device comprising packaging parasitic parameters under a high-frequency switching condition; judging whether the oscillation amplitude of the switch transient current change rate measurement waveform is reduced compared with the switch transient current change rate reference waveform or not; determining the correlation between the packaging parasitic parameter and the switching transient current change rate oscillation amplitude; predicting whether the packaging of the gallium nitride power device is degraded or not; the change of the change rate of the transient current of the switch is reflected through packaging parasitism, and whether the packaging of the gallium nitride power device is degraded or not is monitored by using packaging parasitism parameters, so that an early signal of the packaging degradation of the device can be effectively identified, and an early tiny packaging degradation sign can be captured; and the accuracy of packaging degradation monitoring is high.
Owner:CHINA ELECTRONICS RELIABILITY AND ENVIRONMENTAL TESTING INSTITUTE ((THE FIFTH INSTITUTE OF ELECTRONICS MINISTRY OF INDUSTRY AND INFORMATION TECHNOLOGY) (CHINA SAIBAO LABORATORY)

Electrical equipment operation monitoring system based on intelligent control

The invention relates to the technical field of power distribution monitoring, and discloses an electrical equipment operation monitoring system based on intelligent control, and the system comprises a grid structure recognition unit which collects a switch contact signal, and determines a real-time power grid topology model; the short-circuit capacity evaluation unit reconstructs a node admittance matrix by using a real-time power grid topology model, and calculates node equivalent short-circuit impedance; the transient feature extraction unit samples a node transient current signal and extracts a high-frequency transient component sequence; a monitoring fixed value follow-up setting unit determines a mapping relation between node equivalent short-circuit impedance and short-circuit capacity, and a monitoring threshold value is corrected in a follow-up mode; according to the system and the method, a physical coupling mechanism of the monitoring constant value and the power grid rigidity is established, sensitivity mismatch caused by grid structure reconstruction is eliminated, and the sensing capacity of the system to the initial degradation of equipment is enhanced. The transient integral energy of the high-frequency transient component sequence is calculated, and an abnormal operation signal is generated when the transient integral energy deviates from a monitoring threshold value.
Owner:QUANZHOU XINKE AUTOMATION EQUIP CO LTD

Image sensor readout load current source module, readout system and imaging equipment

ActiveCN119996864BHemt circuitsControl theory
This invention discloses a load current source module, readout system, and imaging device for image sensor readout, relating to the field of image sensor technology. It includes: a current mirror circuit; a negative impedance transformation circuit, which generates negative resistance or capacitance to cancel out the parasitic resistance or capacitance of the VSL itself; and a charge / discharge acceleration circuit. This invention allows the load current source module to internally incorporate a negative impedance transformation circuit and a charge / discharge acceleration circuit. On one hand, the negative impedance transformation circuit generates negative impedance to cancel out the parasitic capacitance and resistance present in the VSL signal establishment, thereby accelerating the small signal establishment speed. On the other hand, the charge / discharge acceleration circuit provides a larger transient current to accelerate the large signal establishment speed. In other words, the load current source module in this application does not change the operating point design of the main current mirror circuit, effectively accelerating the VSL establishment time.
Owner:成都市元视芯智能科技有限公司 +1

Transformer residual magnetism detection method for improving direct current demagnetization

The invention provides a transformer residual magnetism detection method for improving direct current demagnetization, and belongs to the technical field of power equipment detection. The method comprises the following steps: demagnetizing a transformer iron core to eliminate an interference magnetic field, applying direct current excitation through a special winding to generate controllable preset residual magnetism, establishing a detection circuit in which a primary side winding is connected with an external resistor in series and a secondary side winding is open-circuited, and sequentially applying direct current small signal excitation with the same size and opposite directions, the method comprises the following steps: collecting forward and reverse transient current and voltage waveforms, comparing current change rate after filtering to judge the residual magnetism direction, solving the equivalent resistance of an iron core based on the waveform consistent with the residual magnetism direction, obtaining a detection result by combining the monotone fitting relationship between the resistance and residual magnetism, and finally assisting verification and calculating a relative error through an energy method. And if the error does not exceed 5%, it is determined that detection is effective, accurate and lossless detection of the magnitude and direction of the residual magnetism can be achieved, and detection reliability and engineering applicability are effectively improved.
Owner:DC OPERATION INSPECTION BRANCH OF STATE GRID HENAN ELECTRIC POWER CO

A method, system and device for extracting a fundamental phasor of a fault transient current

This invention discloses a method, system, and apparatus for extracting the fundamental phasor of fault transient current, relating to the field of power system fault transient current analysis. The method involves acquiring N transient sampled currents and dividing them into M subsets according to a preset partitioning strategy. The discrete Fourier transform (DFT) output of each subset is then determined. Combining the DFT output expressions of each subset, the first DFT output corresponding to the first exponentially decaying DC offset component and the second DFT output corresponding to the second exponentially decaying DC offset component under the target subset are determined. Finally, the DFT output of the current fundamental phasor is determined by combining the DFT output expression and output results of the target subset, thus obtaining the fundamental phasor. This scheme pre-establishes a preset fault transient current discrete model and sets a preset partitioning strategy, achieving high-precision and rapid extraction of the fundamental phasor, which is beneficial for improving the reliability of power system relay protection.
Owner:EAST CHINA BRANCH OF STATE GRID CORP

Quantitative analysis method for influence of transient current on residual electrical life of high-voltage circuit breaker

The invention relates to the field of circuit breakers, in particular to a quantitative analysis method for the influence of transient current on the residual electrical life of a high-voltage circuit breaker, which comprises the following steps: calculating the influence index of the transient current on the residual electrical life of the high-voltage circuit breaker; constructing a related parameter time sequence; calculating an influence factor of the relevant parameters at the current moment on the relevant parameters at the next moment; predicting numerical values of relevant parameters at the next moment; calculating the influence index of the transient current at the next moment on the residual electrical life of the high-voltage circuit breaker; evaluating the decay speed of the residual electrical life, and dynamically adjusting the maintenance cycle. The method has the advantages that the frequency characteristic of the fault current and the waveform distortion characteristic caused by the harmonic wave are brought into the evaluation system of the residual electrical life, the limitation that only the current amplitude is considered in the traditional method is broken through, the actual physical process of the contact ablation by the transient current can be reflected more truly and more comprehensively by constructing the comprehensive quantitative model, and the evaluation accuracy of the residual electrical life is improved. And the scientificity of an evaluation model and the accuracy of a prediction result are fundamentally improved.
Owner:ANSHAN POWER SUPPLY COMPANY OF STATE GRID LIAONING ELECTRIC POWER COMPANY

Lightning protection filtering assembly

The utility model relates to the technical field of avionic equipment protection, in particular to a lightning protection filtering assembly. Comprising a shell, and a lightning protection module, an anti-reverse module and an EMI filtering module are packaged in the shell. The lightning protection module adopts a transient voltage suppressor (TVS) diode, the clamping voltages are 121V, 19.9 V and 72.7 V respectively, and the response time is less than or equal to 5 microseconds; the anti-reverse module is integrated at a power supply input end, a diode with reverse withstand voltage greater than or equal to 1200V is adopted, and the transient current bearing capacity is greater than or equal to 50A / mu s; the EMI filtering module comprises a pi-type filtering circuit topology; the input interface comprises two circular electric connectors (X1 and X2); and the output interface is a rectangular connector (J3) and is used for integrally outputting all signals and a power supply which are subjected to protection processing. According to the utility model, through module integration, interface centralization and passive high-reliability design, the space and resource waste is reduced, and the module has obvious volume, weight and performance advantages.
Owner:CHANGZHOU MULTIPOLE ELECTROMAGNETIC ENVIRONMENT TECH CO LTD

A Model Predictive Current Control Method and System Based on Online Parameter Identification

This invention discloses a model predictive current control method and system based on online parameter identification. The method independently identifies the resistor using steady-state average information within a switching cycle, and then identifies the inductor using transient current ripple information combined with a logarithmic linearization method. Next, the identified real-time resistance and inductance values ​​are input into a deadbeat-free model predictive current control algorithm to update the coefficients of the predictive model. Based on the latest model parameters and reference current, the controller calculates the ideal voltage vector required to eliminate current error at the next moment, and after amplitude limiting, drives the switching transistor through a PWM module, thereby achieving high-performance control of the coil current. The system includes an online parameter identification module and a model predictive control module. By using this invention, high accuracy and high stability of the magnetic bearing power amplifier are ensured under all operating conditions. This invention can be widely applied in the field of electronic power technology.
Owner:SUN YAT SEN UNIV

Flexible low-frequency transmission line inverse time protection method and system

A flexible low-frequency transmission line inverse time protection method and system are provided. The method uses single-ended electrical quantity to constitute the criterion, after the fault occurs, the signal acquisition device is used to sample the phase current and voltage, and the resulting voltage and current are subjected to the Karenbauer transform to obtain the line mode and the zero mode components, and the integral value of the fault modulus components is used to construct the transient current energy, and the transient energy is used to construct the new inverse time limit characteristic curve equation, and the transition resistance compensation coefficient is introduced to improve the inverse time limit protection performance of the inverse time protection. The method is aimed at accelerating the action time of the protection when a fault occurs in a flexible low-frequency transmission line, and adopts the fault component to construct the transient energy value.
Owner:KUNMING UNIV OF SCI & TECH

A low-frequency terahertz transmitting device and its fabrication and application methods

PendingCN122136686ASolid masersHeterojunctionBand bending
This application relates to the field of terahertz emission, specifically providing a low-frequency terahertz emitting device and its fabrication and usage methods. The device includes an excitation material, which is a heterojunction formed by a perovskite layer and a high-resistivity silicon layer. It also includes a first metal layer disposed outside the perovskite layer and a second metal layer disposed outside the high-resistivity silicon layer. During fabrication, a perovskite solution is first spin-coated onto the high-resistivity silicon to form a perovskite layer, and finally, the metal layers are deposited by vapor deposition. During use, a femtosecond laser is incident from one side of the perovskite layer, and a voltage is applied between the first and second metal layers. The applied electric field of this application enhances the interfacial band bending and widens the depletion layer, while simultaneously forming a stable potential gradient in the thickness direction. This makes the transient current change smoother, increases the time constant, and reduces the rate of change of the transient current over time, thereby increasing the proportion of the low-frequency terahertz component and achieving enhanced low-frequency radiation.
Owner:NORTHWEST UNIV

Lighting device having transient current suppressing function

A lighting device includes a rectifying circuit, first filtering capacitor, resistor element, transient current suppressing circuit and voltage divider circuit. The two ends of the first filtering capacitor are connected to a first node and second node respectively. The two ends of the resistor element are connected to the second node and third node respectively. The transient current suppressing circuit includes a switch and first adjusting capacitor. The three ends of the switch are connected to a fourth node, second node and third node respectively. The two ends of the first adjusting capacitor are connected to the second node and third node respectively. The two ends of the voltage divider circuit are connected to the first node and fourth node respectively. The first node, third node and second node are connected to the first and second output ends of the rectifying circuit and grounding point respectively.
Owner:XIAMEN PVTECH CO LTD

Electric Seat Anti-pinch Control Method and Device

This invention provides a method and device for anti-pinch control of electric seats. The method includes real-time acquisition of current, speed, and physical angle during motor operation; when the current motor current exceeds a dynamic current threshold or the transient collision energy exceeds a collision energy threshold, and the current speed is less than a expected reference speed, the motor is controlled to stop or reverse. The dynamic current threshold is determined comprehensively based on a preset angle reference ammeter, load mass compensation, ambient temperature compensation, and a mechanical wear self-learning factor updated with the number of opening and closing cycles; the transient collision energy is calculated only when the transient current change rate exceeds a dynamic slope threshold, at which point an integral observation window is activated. The electric seat anti-pinch control method and device provided by this invention achieve anti-pinch functionality during the operation of the electric seat.
Owner:JIZHI HABITAT TECHNOLOGY (SUZHOU) CO LTD

Electrostatic discharge and current protection circuit for a semiconductor bridge

The application relates to the technical field of semiconductor bridge electrostatic discharge protection and current protection, and discloses an electrostatic discharge and current protection circuit of a semiconductor bridge, which comprises an ESD protection circuit, a current protection circuit and an NMOS connected in parallel, the ESD protection circuit comprises a bidirectional transient suppression diode and a capacitor connected in parallel, the bidirectional transient suppression diode clamps a transient high voltage by breakdown conduction, the voltage is limited in a safe range, the capacitor reduces a voltage rising rate and suppresses overshoot by shunting and absorbing a transient current, the NMOS provides a low-resistance discharge path, and the voltage and current impact applied to the semiconductor bridge are reduced; the current protection circuit comprises a bidirectional rectifier circuit and a detection circuit; and the NMOS is connected between the detection circuits. The application can realize ESD protection and current protection of the semiconductor bridge, prevents current from damaging the structure, and guarantees the safety of the semiconductor bridge working in an electromagnetic and ESD environment.
Owner:HANGZHOU DIANZI UNIV

An on-chip integrated transient-enhanced LED driving circuit

The application discloses a kind of on-chip integrated transient enhanced LED drive circuit, belong to power supply technical field.The circuit is applied to optical isolation system, optical isolation system utilizes light emitting diode (LED) and photodiode (PD) to realize electrical isolation, control end generates signal control LED light emitting, receiving end utilizes PD and converts optical signal into current signal, and voltage signal is amplified by transimpedance amplifier (TIA), and subsequent module processing.Due to the existence of large parasitic junction capacitor of LED, in the process of controlling switch LED, the charge and discharge of parasitic junction can affect the opening speed of LED, and further affect the overall transmission delay of optical isolation system.A kind of transient enhanced LED drive circuit proposed in this paper provides transient current in the moment of opening LED, accelerates the opening of LED.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

SYSTEMS AND METHOD FOR PROTECTING A MOTOR MAGNET DURING A THREE-PHASE SHORT CIRCUIT

This document provides systems and methods for protecting a motor magnet during a three-phase short circuit. A system includes power electronics configured to energize a three-phase electric motor using a plurality of switches, and control switching logic configured to transition the three-phase electric motor into a three-phase short-circuit state using the plurality of switches, and to switch between the three-phase short-circuit state and a three-phase open-circuit state based on a transient current of the three-phase electric motor using the plurality of switches. In some embodiments, the transition from the three-phase short-circuit state to the three-phase open-circuit state occurs in response to the transient current exceeding a threshold value.In some embodiments, the transition to a three-phase short-circuit state occurs in response to at least one of the multiple switches being damaged.
Owner:RIVIAN HOLDINGS LLC

Lightning-proof overhead insulated cable

The utility model provides a lightning-proof overhead insulated cable, which belongs to the technical field of cables and comprises a metal braid layer and a lightning-proof assembly arranged on the outer wall of the metal braid layer, and the lightning-proof assembly comprises a protective layer, a battery cell, a buckle, a conducting ring, a reinforcing rib, a traction rope, a mounting table, a limiting block, a guide rod, a rotating rod and a lightning rod main body. Through the linkage design of the traction rope, the limiting block and the guide rod, the working angle of the lightning rod main body is adjusted, compared with a traditional fixed lightning arrester, the point discharge loss in non-thunderstorm weather can be reduced by 80%, meanwhile, the lightning stroke response speed is increased by 35%, and a multi-layer conductive framework, a metal braid layer, a buckle, a conduction ring and a reinforcing rib are adopted, so that the lightning protection effect is improved. Actual measurement shows that the shielding structure can bear the transient current impact of 200kA / mu s, the conductivity is improved by four times compared with a conventional single-layer shielding structure, and it is ensured that the insulating layer 2 is still kept intact under the electric field intensity of 100kV / m.
Owner:CHENYANG NORTHERN CROSSLINKED CABLE MANUFACTURING CO LTD

A PCB embedded power module with a buried planar roebel coil

The application relates to the field of high-density power integration, in particular to a PCB embedded power module with a buried planar Rogowski coil. The PCB embedded power module provided by the application comprises a power PCB board, a laminated structure, the laminated structure having a plurality of conductive layers and a plurality of insulating layers which are alternately stacked; a power chip which is embedded in the laminated structure of the power PCB board and is electrically connected with at least part of the conductive layers; and a planar Rogowski coil which is embedded in the laminated structure of the power PCB board and is used for sensing the current of the power chip; wherein at least part of the conductive layers of the laminated structure form a containing space through a connecting structure, and the planar Rogowski coil is buried and integrated in the containing space and is electrically isolated from the conductive layers. The application replaces the traditional spiral coil with the planar Rogowski coil by adopting the PCB buried integration method, and high-precision detection of the chip switching transient current of the PCB embedded power module is realized.
Owner:CRRC ZHUZHOU ELECTRIC LOCOMOTIVE RESEARCH INSTITUTE CO LTD

Control method for improving transient performance of network-forming converter

The invention discloses a control method for improving transient performance of a network-forming converter, and the method comprises the steps: active power control: employing a second-order sliding mode control method, outputting an electromagnetic power reference value based on the construction of an improved integral sliding mode surface and a power angle error determined by an actually measured power angle and a target power angle, and adjusting the active power actually output by the converter; reactive power and voltage control: adopting a switching control method to select a direct voltage control mode or a reactive power-voltage droop control mode based on the relationship between the actual output voltage of the converter and a preset safety voltage threshold; fault transient current suppression: when a power grid fault is detected, inputting dynamic virtual impedance, adjusting the ratio (R / L) of resistance to inductance of the dynamic virtual impedance, and actively changing the total loop impedance characteristic of the output end of the converter; after the voltage of the power grid is recovered, the virtual recovery resistor is put into use, and transient current in the voltage recovery period is suppressed.
Owner:CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY

Pure hardware double-key power switch circuit

The utility model discloses a pure-hardware double-button power switch circuit, and the circuit comprises a first button and a second button which are respectively used for controlling the on and off of the circuit. According to the utility model, the on-off control logic of the power supply is separated through the independent double keys, and the interlocking feedback design of the P-MOS tube and the N-MOS tube is combined, so that the functions of one-key opening self-locking and one-key forced turn-off are realized, and the state disorder caused by mistaken touch is thoroughly avoided; a pure hardware architecture does not need program control or a special chip, so that the cost and the size are greatly reduced, and a surface-mounted device is adapted to meet the miniaturization requirement; the transient suppression network formed by the capacitor and the resistor effectively absorbs transient current conducted by the parasitic diode and power-on interference, prevents self-starting of the power supply, ensures stable operation of the system in a complex scene, and has the advantages of low cost, high reliability and wide applicability.
Owner:SHENZHEN MINEW TECH CO LTD