3366 results about "Overvoltage" patented technology

The invention relates to the technical field of power grid monitoring, and discloses a voltage sensor multi-parameter real-time monitoring method and device in an Internet of Things environment. According to the method, real-time voltage fluctuation data of a target area is acquired by deploying a multi-channel voltage sensor array and is transmitted to an edge computing node; dynamic feature extraction is executed in the edge nodes, and a multi-dimensional feature matrix containing voltage fluctuation ratio, harmonic distortion and phase deviation features is generated; identifying voltage sag, overvoltage and harmonic resonance event characteristics based on an anomaly detection model; spatial correlation modeling is carried out in combination with power grid topological structure parameters, the coupling strength of adjacent sensor node parameters is calculated, and a multi-parameter correlation map containing event propagation paths and influence ranges is generated; inputting the voltage into a diagnosis model to generate a power grid state diagnosis report, and dynamically adjusting the sampling frequency and filtering parameters of the voltage sensor according to the power grid state diagnosis report. According to the method, real-time monitoring and analysis of multiple parameters of the power grid can be realized, and comprehensive support is provided for power grid state evaluation.

The invention provides a fault ride-through control method and a fault ride-through control system for a grid-forming converter, which are characterized in that the current of the grid-forming converter under an asymmetric fault is controlled by adopting a negative-sequence current reference generation strategy aiming at an inner ring of a controller, and negative-sequence reactive current is injected into a power grid; adopting a partial sequence current amplitude limiting strategy to control the maximum phase current amplitude of the injected asymmetric current not to exceed an amplitude limiting value; controlling the boundary of an active reference value by adopting an active reference value amplitude limiting strategy for an active synchronization ring; a synchronous damping link is adopted to enhance damping in power angle swing; for a reactive voltage loop, a reactive voltage variable coefficient control strategy is adopted to control the output of the maximum reactive current; and an internal potential locking strategy is adopted to suppress overvoltage. According to the invention, negative-sequence reactive power is provided, and overcurrent of each phase is avoided; the power angle characteristic is improved, and the transient stability is improved; stable transient voltage support is provided in a current output capability range; and after the fault is recovered, the voltage of the converter grid-connected point is smoothly recovered.

The invention provides a transient overvoltage risk assessment method, device and equipment for an AC / DC system containing high-proportion new energy, and a storage medium. Relates to the technical field of power systems and automation thereof. The method comprises the following steps: modeling a power system into a discrete nonlinear power system based on phase change measurement unit data, constructing a state space, introducing a Koopman operator to determine an observation function, and establishing a dynamic time sequence track prediction model based on the observation function to output a predicted dynamic time sequence track; an Informer model is constructed, in response to an input predicted dynamic time sequence track, feature weights are distributed through a ProbSparse self-attention mechanism, hierarchical feature down-sampling is performed by using a distillation mechanism, and a predicted transient voltage amplitude is output; and quantifying the transient overvoltage risk level according to the predicted transient voltage amplitude. According to the method, the problems of low isolated time section feature prediction precision and poor long-sequence dynamic evolution feature evaluation timeliness in the prior art are solved.

The invention discloses a linearity closed-loop optimization method for a semiconductor gas sensor with adjustable voltage dynamic compensation, which relates to the technical field of gas detection and comprises the following steps: controlling the semiconductor gas sensor to start in a clean air environment, outputting an initial test voltage sequence through a voltage regulator, the method comprises the steps of collecting sensor reference resistance under different voltages, screening out initial working voltage with the minimum resistance fluctuation quantity, synchronously collecting initial environment temperature and humidity, and calibrating the sensor reference resistance based on preset temperature and resistance coefficients and humidity and resistance coefficients to obtain initial reference resistance. By dynamically adjusting the working voltage and combining real-time compensation on the environment temperature and humidity, the interference of environment factor fluctuation on the resistance characteristic of the sensitive material can be continuously counteracted, so that the linear relation between the output signal of the sensor and the target gas concentration is kept stable, the dynamic optimization of the linearity in a complex environment is realized, and the sensitivity of the sensor is improved. And more reliable basic data is provided for gas concentration detection in an industrial scene.

The invention provides a device for inhibiting drain-source overvoltage and overcurrent through active gate drive of a silicon carbide MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor), aiming at solving the problem of voltage or current overshoot caused by circuit parasitic parameters in a high-speed switching process of the SiC MOSFET and simultaneously considering the switching speed and energy loss balance. According to the device, drain-source voltage vdc and direct-current bus voltage of the SiC MOSFET are collected to serve as feedback signals, and gate driving voltage and equivalent gate resistance are dynamically adjusted; in a key stage (a Miller plateau switching-on period and a voltage rising period switching-off period) of a switch transient state, a gate resistance network is switched through a logic control circuit, and suppression of drain current overshoot and drain-source voltage overshoot is realized. Simulation verification shows that the device can reduce voltage overshoot by 20%-30% and current overshoot by 25%-60%, only a single voltage feedback channel is needed, the cost is obviously lower than that of a traditional multi-signal acquisition active gate driving scheme, and the device is suitable for a high-efficiency SiC MOSFET power converter.

The invention discloses an intelligent self-adaptive suppression method for oscillation of a data-driven SVG (static var generator) grid-connected system. Obtaining the capacitor voltage of the direct current side of the SVG and the actual voltage and the actual current of the grid connection point of the SVG, and respectively calculating the active power output by the SVG and the voltage amplitude output by the SVG according to the actual voltage and the actual current; a current reference value is generated through a voltage outer loop; the active power output by the SVG, the voltage amplitude output by the SVG and the voltage of the direct current side of the SVG are input into a DeePC controller to be processed, and an additional current reference value is obtained; and then the current error is obtained by adding the current reference value output by the voltage outer loop and subtracting the actual current, and then the current error is input to the voltage inner loop for processing to obtain a modulation wave voltage amplitude signal. According to the method, the oscillation of the converter grid-connected system can be suppressed under the condition that the dynamic characteristics of the converter and the conditions of the power grid are changed, and the problems of insufficient fixed structure and parameter sensitivity of the traditional SVG are solved.

The invention relates to the technical field of power systems, and discloses a voltage regulation system of reactive power compensation equipment, which is characterized in that harmonic interference is filtered and eliminated through a voltage reactive power sensing unit, and accurate power grid parameters are acquired; a load trend pre-judgment unit analyzes the historical load curve and the real-time change trend to generate a future pre-judgment signal; the dynamic compensation calculation unit combines the current power grid state with the prediction to calculate the optimal compensation capacity and generate a switching instruction, after the hybrid switching actuator receives the instruction, a thyristor is triggered firstly to realize inrush current-free conduction, a contactor is switched to maintain low power consumption after the current is stable, and meanwhile, the compensation state monitoring unit performs closed-loop adjustment on parameter deviation, so that the optimal compensation capacity is obtained. The multi-dimensional protection unit prevents overvoltage, overcurrent and overheating, the double-path power supply guarantees continuous operation when the main power supply is abnormal, the intelligent communication unit realizes data uploading and remote cooperation, quick response switching of reactive compensation equipment and guarantee of safety of a large-scale power grid are realized, and inrush current impact in the switching process is effectively inhibited.

The invention provides an impedance scanning device based on network side voltage dynamic compensation under a three-phase voltage imbalance working condition, and relates to the technical field of new energy station power electronic converter topology and control, the device comprises a three-phase rectifier, a direct current bus capacitor, an inverter, a voltage compensation device, a frequency sweeping device, a circuit breaker and a series transformer part, the three-phase rectifier is connected in series with inverters of the voltage compensation device and the frequency sweep device, a secondary side of a series transformer of the voltage compensation device is connected in series with a network side, a secondary side of a series transformer of the frequency sweep device is connected in series with a grid-connected point, and a primary side of the series transformer is connected to the inverters and is coupled to a secondary side of the series transformer; according to the device, the power grid side voltage is rectified through the voltage compensation unit and is compensated to the grid side after being subjected to single-stage inversion transformation, voltage compensation is achieved through the energy of a power grid when the voltage is unbalanced, and an external energy source or an interference source does not need to be introduced. After compensation, the accuracy of the frequency sweeping result is obviously improved.

The present application provides a converter and a chopper transistor blocking control method therefor. According to the chopper transistor blocking control method, when switching transistors in a converter need to be blocked, switching transistors in a primary side circuit connected to a transformer of the converter are blocked, and switching transistors in a secondary side circuit are blocked when the current on a branch where a secondary side winding in the transformer is located is zero, or batch blocking of the switching transistors in the secondary side circuit is completed after the current on the branch where the secondary side winding is located recirculates to zero, thereby avoiding overvoltage damage to the switching transistors caused by the current on the branch where the secondary side winding is located recirculating by means of the junction capacitance of the switching transistors in the secondary side circuit.

The invention discloses an insulation state fusion detection method, system, medium and equipment under transient impact in a cable operation process, and the method comprises the steps: synchronously collecting a transient impact signal and a partial discharge signal of a cable under the transient impact effect; performing time-frequency domain separation on the acquired transient impact signal and the partial discharge signal to obtain a transient impact component and a partial discharge component after separation; when it is detected that the amplitude of the transient impact signal exceeds a preset threshold value, a partial discharge detection window is started, and whether a partial discharge signal exists or not is detected in the window period; if a partial discharge signal is detected, multi-dimensional characteristic parameters of the partial discharge signal are extracted, a state vector is constructed in combination with environmental parameters, the state vector is input into a pre-trained machine learning model, and a cable insulation state grade is output; if the partial discharge signal is not detected, performing inversion calculation on the transient impact signal based on a transmission line model, and reconstructing an overvoltage waveform; and extracting propagation characteristic parameters according to the reconstructed overvoltage waveform, and judging the insulation defect type according to the propagation characteristic parameters.

According to the cable multi-parameter fusion sensor and method, in the cable multi-parameter fusion sensor, a shielding shell is of an open-close type metal annular structure; the zero-flux sensor module is arranged on the inner layer of the shielding shell so as to detect a cable sheath ring current signal; the pulse current sensor module is arranged on the outer side of the zero-flux sensor module so as to detect a cable partial discharge pulse current signal and an overvoltage impact current signal; the magnetic shielding layer is arranged between the zero-flux sensor module and the pulse current sensor module to shield low-frequency magnetic field interference; the zero magnetic flux sensor module and the pulse current sensor module share the shielding shell to form an electromagnetic shielding structure.

The invention relates to an FOC control method based on an automobile air conditioner module motor without a Hall sensor, and belongs to the technical field of automobile electronics. The method comprises the following steps: injecting double-frequency voltage pulses into a stator in stages to position a rotor; collecting current through a sampling resistor and filtering to construct a rotor flux linkage distribution model, and presetting rectangular axis current in combination with noise reduction of a miniature acoustic sensor and air speed gear of an air conditioner; an extended Kalman filter observer is adopted to reversely deduce the load torque, and the torque change rate is monitored to trigger instantaneous load impact protection; the voltage space vector amplitude is corrected through voltage feed-forward compensation, a resistor-capacitor series filter circuit is additionally arranged, and phase dislocation pulse width modulation is adopted for resisting interference; and establishing a motor efficiency-rotating speed-load three-dimensional optimization method, starting dynamic flux-weakening control, and estimating the winding temperature through the stator resistance to adjust the flux-weakening depth. Accurate starting and dynamic load adaptation of the Hall-sensor-free motor are achieved, starting out-of-step and noise exceeding are avoided, and stable air volume of an automobile air conditioner and long-term reliable operation of the motor are guaranteed.

A power converter having an overvoltage protection mechanism is provided. A node between a second terminal of the high-side switch and a first terminal of a low-side switch is connected to an inductor. When an output current or an output voltage of the power converter must be released, the output current of the power converter flows to the input power source sequentially through the inductor, the high-side switch being turned on. Under this condition, when an overvoltage protecting circuit determines that a current or a voltage of the inductor or a current or a voltage of the input power source is larger than a threshold, the output current of the power converter flows to a ground through the overvoltage protecting circuit.

The invention discloses a rapid thermal simulation method and system for a semiconductor power assembly, and relates to the technical field of semiconductors, and the method comprises the steps: collecting a voltage V (t) signal and a current I (t) signal of the semiconductor power assembly in real time through a voltage and current sampling circuit, constructing a power pulse input sequence A, and carrying out the hot carrier accumulation analysis according to the power fluctuation change amplitude; introducing a transient thermal resistance function Zth (t), fitting the transient thermal resistance function Zth (t) with a hot carrier pulse response index Mcx after numerical integration to analyze junction temperature change caused by power pulse, and evaluating an equivalent junction temperature dynamic change rate; when the analysis result is that the thermal drift out-of-control trend exists, thermal risk analysis is carried out, and thermal risk state assessment is generated; the simulation model optimizes thermal model parameters and outputs thermal control suggestions through a rollback correction path, and the working state of the semiconductor power assembly is automatically adjusted. According to the method, real-time monitoring and effective prevention and control of thermal runaway can be realized, and the reliability and safety of the semiconductor power assembly are improved.

The invention relates to the technical field of novel illumination, and discloses a wide-voltage light source intelligent control method integrated with a step-down regulation strategy, which comprises the following steps: establishing a mapping table of a voltage interval and a basic compensation slope; indexing a basic slope according to the real-time input voltage; extracting a load voltage direct current component representing the LED junction temperature to generate a thermal drift correction coefficient; dynamically reducing the target slope to match the natural attenuation characteristic of the inductive current; according to the invention, the junction temperature is reversely deduced through the voltage signal, a parameter self-calibration closed loop of a physical level is constructed, the phase margin of a control loop of a whole temperature range is locked under the condition of zero newly-added hardware cost, the problem of dynamic response hysteresis under a high-temperature working condition is solved, and the reliability of the system is improved. And the optical consistency of precise illumination is ensured.

The invention relates to the technical field of industrial control systems, and discloses an industrial and commercial energy storage battery management system and method.The industrial and commercial energy storage battery management method comprises the steps that a battery main loop switching device is controlled to superpose micro-disturbance signals, a voltage response sequence is collected in real time, the approximate entropy value of the voltage response sequence is calculated, the battery operation mode is determined according to entropy value threshold value comparison, and a corresponding control strategy is executed; according to the method, the electrochemical stability in the battery is directly perceived through order degree analysis of the voltage response sequence, model-free state recognition is achieved, meanwhile, a resource self-adaptive mechanism that macroscopic monitoring triggers microscopic calculation is constructed, the decision reliability is improved through electrochemical and thermodynamic signal cross validation under the complex working condition, and the method is suitable for large-scale popularization and application. And a dynamic control system with both real-time performance and safety is formed.

The invention relates to a quantitative evaluation method and system for temporary overvoltage of a new energy multi-infeed system, and the method comprises the steps: calculating the voltage of any preset potential fault node in the new energy multi-infeed system under the condition that the potential fault node has an AC fault, voltage increment of a system grid-connected point during a fault recovery period; and then traversing all preset potential fault nodes, finding out the potential fault node corresponding to the maximum voltage increment, and evaluating the potential fault node as the fault node with the most serious system overvoltage risk. According to the method, the overall overvoltage risk level of the system can be evaluated, and the key fault node causing the most serious overvoltage can be clearly identified.

The invention provides a system temporary overvoltage evaluation method under an asymmetric fault, and relates to the field of power systems, and the method comprises the steps: responding to a VSC grid-connected system AC fault, carrying out the equivalence of a VSC fault ride-through reactive power support strategy in a positive sequence network, carrying out the equivalence of a VSC unbalanced voltage suppression strategy in a negative sequence network, and carrying out the equivalence of the VSC fault ride-through reactive power support strategy in the negative sequence network; obtaining a single-machine equivalent model; the single-machine equivalent model is merged into a network admittance matrix, a corrected admittance matrix is constructed, and a corrected impedance matrix is solved; setting short-circuit boundary conditions, calculating short-circuit current increment of a fault point as an equivalent current source, solving voltage increment of each PCC point according to the corrected impedance matrix and the equivalent current source, and synthesizing three-phase voltage; and forming a TOV evaluation result based on the phase voltage maximum value of each PCC point, and calculating a voltage safety index according to the result. According to the invention, comprehensive analysis and evaluation of the temporary overvoltage risk of the new energy grid-connected system are realized.

The invention provides an emergency lighting control chip and an emergency lighting system, the emergency lighting control chip is connected with an energy storage battery, an emergency lighting unit and a first node, the first node is used for receiving input current, both the energy storage battery and the emergency lighting unit are provided with positive ends and negative ends, and the emergency lighting control chip comprises a switch module. By setting the switching time sequence of the switch module, the functions of constant-current charging, full charge protection, overvoltage protection and emergency discharging can be realized in the emergency lighting control chip, an additional LED lamp does not need to be specially arranged, and the cost of manual wiring is lower.

The invention relates to the technical field of ring main units, and provides a self-adaptive protection device for a ring main unit, which comprises a cabinet body, a gas tank mounted on the back of the cabinet body and filled with environment-friendly insulating gas, and a pressure relief pipe with one end communicated with the top of the gas tank and used for pressure relief of the gas tank, the top of the gas tank is provided with a pressure relief regulation and control assembly, and the top of the pressure relief regulation and control assembly is provided with a dustproof assembly. The pressure relief regulation and control assembly comprises a funnel-shaped main speed discharging barrel arranged at the top of the air box and a butt joint sleeve for connecting the main speed discharging barrel with the pressure relief pipe in a sealed mode. During use, the main pressure relief channel and the branch slow-heating pressure relief channels are utilized and respond to instantaneous high-pressure impact and continuous hot pressing respectively, so that deformation and damage of the gas tank caused by instantaneous arcing overpressure are effectively prevented, and the potential safety hazard that pressure accumulation caused by abnormal slow temperature rise cannot be released in time is eliminated; and self-adaptive protection of the ring main unit gas tank is realized.

The invention belongs to the technical field of energy storage, and particularly relates to a portable energy storage power supply offline grid-connected detection and expansion system, which comprises a power grid access module, a multi-rate power grid state detection module, a central control module, a self-adaptive isolation module, an energy management module, an expansion battery interface module and a man-machine interaction and communication module, the multi-rate power grid state detection module is used for providing ultra-fast response to power grid transient abnormity and accurate monitoring of power grid steady-state parameters at the same time, and comprises a transient abnormity rapid detection sub-module and a comprehensive parameter accurate detection sub-module. And the self-adaptive isolation module is directly associated with the transient abnormity rapid detection sub-module. Through a hardware acceleration detection mechanism of the transient abnormity rapid detection sub-module and a high-speed solid-state relay array of the self-adaptive isolation module, the system can respond to transient overvoltage, rapid frequency deviation or zero crossing abnormity and complete isolation action.

The invention discloses a cable partial discharge analysis method and device based on oscillatory waves. The method comprises the steps that the oscillatory waves are applied to a tested cable, and low-frequency envelopes and high-frequency pulses are synchronously collected; performing structure normalization according to cable parameters; encoding the environment and working condition data into a condition vector to implement condition normalization; carrying out domain self-adaptive alignment with an ideal template clustered according to a model, a length and a joint / terminal type, and obtaining a difference feature; constructing a PRPD joint fingerprint, and counting a pulse phase, an amplitude, an envelope attenuation rate and / or an equivalent Q; outputting defect positions, types and confidence intervals based on the difference features and the joint fingerprints; and adaptively determining multi-gear upper pressure and advanced shutdown according to the information gain, and generating maintenance priority and retest interval suggestions. Through step-by-step normalization processing, domain adaptive alignment and fusion of PRPD combined fingerprint features, diagnosis stability and reproducibility are enhanced, weak discharge and early defect detection capability are enhanced, and complex working conditions and cross-trigger adaptability are enhanced.

The embodiment of the invention provides a circuit protection device and a chip, and the device comprises a detection module which is used for detecting whether the voltage of a power supply exceeds a voltage protection threshold, and outputting a low-level signal to a time hysteresis control module when the voltage exceeds the voltage protection threshold; if not, a high-level signal is output to the time hysteresis control module; the time hysteresis control module is used for receiving the low-level signal output by the detection module and controlling an MOS tube in the time hysteresis control module to be turned off; and the control module is used for receiving the high-level signal output by the detection module, timing and controlling the MOS tube to start when the timing time reaches the preset time, so that the problem that the power supply end fluctuates between a protection mode and a normal working mode when the input power supply rapidly fluctuates in the overvoltage and power failure protection circuit in the related technology is solved. In addition, common simple devices are needed for implementation, the cost is low, and the reliability is high.

The invention belongs to the technical field of power transformation equipment, and particularly relates to a low-voltage dynamic reactive compensation switching device which comprises a shell, a photoelectric isolation module and a communication module. The shell is in an inverted-T shape, a switching switch is arranged at the front end of the shell, wiring ports are symmetrically formed in the upper side and the lower side of the shell, and wiring bolts are installed on the wiring ports. A photoelectric isolation module is arranged on one side of the shell, and the heat dissipation holes dissipate heat for the photoelectric isolation module. According to the scheme, a thyristor and contactor hybrid switching switch is adopted, zero-crossing switching is realized by the thyristor during dynamic load fluctuation, and inrush current control is less than or equal to 10 times of rated current. And when the static state is stable, the contactor is automatically switched to be conducted, and the power consumption is reduced to 1.5 W and is greatly reduced compared with a pure thyristor scheme, so that the impact is avoided and the energy consumption is reduced. The thyristors are in bidirectional anti-parallel connection, and are matched with zero-cross detection logic of the controller, so that overvoltage and transient harmonic waves in the switching process are thoroughly eliminated, no interference is caused to a power grid, and the service life of the device and power grid equipment is prolonged.

The invention provides a display device and a display method. The display device comprises a display panel and a driving chip, the driving chip comprises a voltage regulating unit, an overvoltage driving unit and a triggering unit; the trigger unit is used for detecting whether the current display picture of the display panel is a heavy-load picture or not, and when the display picture is the heavy-load picture, the trigger voltage regulation unit and the overvoltage driving unit are triggered to work cooperatively; the voltage adjusting unit is used for adjusting a target driving voltage corresponding to a target gray scale in the liquid crystal driving voltmeter, so that the lighting effect reaches the preset brightness when the display panel displays a white picture; the overvoltage driving unit is used for starting a driving function, adjusting the parameter configuration table and performing overvoltage driving on a data line of the display panel based on the parameter configuration table and the target driving voltage so as to improve the charging rate of the heavy-load picture, so that the charging rate is improved by detecting the heavy-load picture and cooperatively adjusting the voltage and overvoltage driving, and the charging efficiency is improved. The method has the advantages of improving the charging rate of a heavy-load picture, eliminating display defects and improving the display quality.

A multi-dimensional quantitative index-based power system flexibility safety assessment method comprises the following steps of: firstly, quantifying frequency regulation capability, defining a flexibility supply range index, a minimum supply level index and a response rate index, and respectively representing a resource regulation range, a lower limit power proportion and a climbing rate; for source-network-load-storage resources, an up-regulation / down-regulation flexibility model is established. Secondly, voltage stability capability evaluation is carried out, transient low / overvoltage indexes are provided, and the node voltage deviation degree after large disturbance is quantified; and calculating the comprehensive voltage regulation capability index of the whole network by combining the reactive voltage sensitivity and the resource reactive regulation capability. And thirdly, system-level safety evaluation is carried out, and the flexibility adequacy of the system is evaluated through the flexibility insufficient probability, the margin expectation and the vacancy expectation. Compared with a traditional method, the problem that flexibility directivity, time scale difference and resource dynamic characteristics are difficult to quantify is solved.

The invention discloses a multi-machine common-bus generator system stator grounding fault active arc extinction method based on online calculation of ground capacitance parameters, and the method comprises the following steps: S1, connecting a controllable current source in parallel with a secondary side of a generator neutral point grounding transformer, and injecting current into a neutral point; extracting a voltage component with the same frequency as the injection current, and calculating a ground capacitance parameter of the generator system on line through the voltage component and the injection current value; s2, measuring the three-phase phase voltage of the generator and the phase value of the zero-sequence current at the generator end of the generator, and solving the fundamental wave potential of a fault point based on the measured value; deriving a compensation current needing to be injected at the generator end side of the fault phase generator, and injecting the compensation current at the generator end; and S3, after compensating current is injected into the generator ends to realize arc extinguishing of fault points, measuring the generator end zero-sequence current phase of each generator again, and performing fault selective positioning, thereby determining a fault unit in the multi-generator common-mother system. According to the method, effective arc extinction can be realized, and the fault unit can be reliably judged.

The invention provides a PT ferromagnetic resonance overvoltage suppression system and method based on graded damping. The system comprises a secondary resonance elimination module, the secondary resonance elimination module comprises a three-stage damping branch circuit which is connected in series with an open triangle of a voltage transformer, the three-stage damping branch circuit comprises a first current-sensitive resonance eliminator, a second current-sensitive resonance eliminator and a fixed resistor which are connected in parallel, and a branch circuit of the first current-sensitive resonance eliminator is connected in series with a first switch; a branch of the second flow-sensitive resonance eliminator is connected in series with a second switch, and a branch of the fixed resistor is connected in series with a third switch; the fan is used for carrying out air cooling on the first flow-sensitive resonance eliminator, the second flow-sensitive resonance eliminator and the fixed resistor; and the control module is used for controlling on or off of the first switch, the second switch and the third switch. Resonance early recognition is achieved through transient energy comprehensive criteria, three-level damping dynamic switching and fan intelligent temperature control are combined, and the three core problems of response lag, insufficient heat dissipation and weak self-adaption in ferromagnetic resonance suppression are solved.

The invention provides an overvoltage transient suppression method and system for an automobile generator rectifier and a medium, and relates to the technical field of rectifiers, and the method comprises the steps: carrying out the dynamic continuous data collection of an automobile generator through a transient data collection device, and obtaining an output voltage waveform; a load rejection identification mechanism is introduced to identify and analyze the output voltage waveform, and a real-time load rejection event is obtained; triggering an active protection circuit based on the real-time load throwing event, and generating a real-time protection control decision; and performing transient suppression on the rectifier according to the real-time protection control decision. The technical problems that in the prior art, overvoltage protection of an automobile generator rectifier is slow in response speed and low in protection precision, and the overvoltage transient state cannot be effectively restrained are solved. The technical effects of accurately identifying and responding to the overvoltage event and improving the timeliness and effectiveness of overvoltage transient suppression of the automobile generator rectifier are achieved.

The invention relates to the technical field of electrical variable measurement, in particular to a power distribution overhead line fault traveling wave positioning anti-electromagnetic interference method and system and a medium. According to the method, a broadband equivalent circuit model of a power distribution overhead line is constructed based on a vector matching method and is used for simulating transmission characteristics of fault traveling waves and switching operation overvoltage; performing multi-scale decomposition on the acquired signals by adopting a wavelet transform algorithm, extracting disturbance signal parameters, and calculating traveling wave propagation characteristics according to different fault types and switch working conditions; constructing an electromagnetic disturbance propagation coupling model, and performing time-frequency domain analysis by taking the traveling wave propagation characteristics, the disturbance signal parameters and the line environment parameters as input to obtain coupling characteristics of electromagnetic disturbance; carrying out numerical simulation by utilizing electromagnetic field simulation software, analyzing the influence of line environment parameters on coupling characteristics, and optimizing model parameters; and finally, analyzing the coupling characteristics of electromagnetic disturbance, eliminating the influence of electromagnetic interference on the traveling wave signal through a reverse decoupling algorithm, and achieving the accurate fault positioning of the power distribution overhead line.