9055 results about "Resistor" patented technology

The invention discloses a fault ride-through hierarchical control method for a network-constructed converter, and the method comprises the steps: introducing a virtual resistor formed by fault current negative feedback into the voltage and current inner loop control of the network-constructed converter based on VSG control through a current inner loop dynamic amplitude limiting control layer after the converter enters a fault ride-through state, the size of the virtual resistor is adjusted in real time along with the amplitude of the fault current so as to carry out dynamic current limiting control on the virtual resistor; and the power outer loop dynamic compensation control layer dynamically adjusts an active power instruction value and a reactive power instruction value of the network construction type converter based on VSG control during the fault ride-through period according to the voltage drop degree of the power grid after the converter enters the fault ride-through state. And respectively performing active-frequency control and reactive-voltage control based on the active power instruction value and the reactive power instruction value. In addition, the method also comprises a state coupling and parameter self-adaption module. According to the method, the GFM converter can have better dynamic performance in the fault recovery stage.

The invention discloses a high-precision current detection circuit calibration system, and belongs to the technical field of current detection circuit calibration. Comprising a shunt resistor, a Hall sensor array, a chopping amplifier, a low-noise operational amplifier, a temperature sensor, an ADC acquisition unit, an RC low-pass filter, a signal conditioning unit, a main control unit, an environmental parameter adaptive compensation module and a gain adaptive adjustment module. After an original signal is obtained from a multi-channel sensor, a dynamic error model is constructed in combination with temperature data, a long-term imbalance trend is extracted by using a moving average or median filtering algorithm, and real-time compensation is performed through a pre-calibrated temperature-drift function, so that the system maintenance period is remarkably prolonged.

The invention relates to the technical field of wireless communication, and provides a radio frequency low-noise amplifier which comprises an input matching module, a power amplification module, an output matching module, an RC attenuation module and an RC feedback module, the first end of the first inductor serves as the input end of the output matching module, the first end of the first inductor is connected with the output end of the power amplification module, the control end of the switch and the first end of the first adjustable resistor, and the second end of the first inductor is connected with the first end of the second inductor and the first end of the third capacitor. The output end of the switch is connected with the first end of the first capacitor and the first end of the second capacitor. The second end of the second capacitor is connected with the second end of the first adjustable resistor and the second end of the second inductor and used for being connected with a power supply. The second end of the first capacitor is connected with the second end of the third capacitor and serves as the output end of the output matching circuit. The radio frequency low-noise amplifier is adjustable in gain, low in noise and good in linearity performance.

The invention discloses a method for detecting abnormal metering performance of an intelligent electric energy meter, which belongs to the technical field of electric energy metering equipment and comprises the following steps of: 1, establishing a reference response curved surface of parasitic parameters of a voltage sampling resistor and a current transformer in the electric energy meter relative to temperature and humidity; step 2, during the operation period of the electric energy meter, acquiring the real-time measurement value of the parasitic parameter in situ; and step 3, matching the real-time measurement value with the reference response curved surface. According to the method, an active matching model library can be constructed by fusing an underlying physical model of a component and a mapping rule set for a complex environment with sudden change of plateau outdoor temperature and humidity, the internal mechanism that parasitic parameters change along with temperature and humidity is explained from the physical essence level, and the limitation of a pure data statistical method is made up; the dynamic error judgment threshold value can adapt to environmental stress changes in real time, and the accuracy of metering performance anomaly detection and the complex environment adaptability are effectively improved.

Various embodiments provide an antenna assembly and associated systems, devices, and methods. The antenna assembly may include two or more antennas, including a first antenna and a second antenna, coupled to a ground plane. The antenna assembly may further include an isolation network coupled to the ground plane between the first and second antennas. The isolation network may include a conductive structure between conductive antenna portions of the first and second antennas, and an isolation circuit coupled between the conductive structure and the ground plane. The isolation circuit may include a resistor, an inductor, and / or a capacitor (e.g., coupled in parallel with one another). Other embodiments may be described and claimed.

The invention provides a carbon ceramic resistor and a preparation method thereof, and relates to the technical field of special material production of power systems and electrical equipment. The preparation method comprises the steps that carbon-containing electric conductor raw materials are mixed to obtain a first mixed raw material, and the carbon-containing electric conductor raw materials comprise, by mass, 15 parts of gluconic acid, 10 parts of aluminum oxide and 55 parts of deionized water; performing hydrothermal reaction on the first mixed raw material to obtain a carbon-containing conductor precursor; the carbon-containing conductor precursor is carbonized in a protective atmosphere, a carbon-containing conductor of a core-shell structure is obtained, and the carbon-containing conductor takes aluminum oxide as an inner core and takes a conductive carbon material formed by gluconic acid as a conductive outer shell; mixing the carbon-containing electric conductor with the core-shell structure with a carbon ceramic matrix raw material to obtain a resistor blank; and sintering the resistor blank to obtain the carbon ceramic resistor. The uniformity, the stability and the reliability of the carbon ceramic resistor are improved, so that the carbon ceramic resistor can better meet the application requirements of ultrahigh-voltage and extra-high-voltage alternating-current power transmission systems.

The invention relates to the technical field of network construction type converter control, in particular to a network construction type converter fault ride-through method and system based on dynamic virtual resistance control, and the method comprises the steps: adding a control link based on virtual impedance in a network construction type converter control system; detecting the actual value of the power grid voltage, and judging whether the power grid voltage drops or not; detecting the current amplitude output by the grid-forming converter in real time, and judging whether the current amplitude exceeds a set value or not; if one of the two conditions is met, a virtual impedance control link is started: stage-type current limiting control is performed on the virtual resistor, and the size of the virtual resistor provided by the network-forming converter to the power system is adjusted in real time along with the amplitude of the fault current; and when the power grid voltage recovers and the current amplitude is smaller than the set value, the virtual resistor staged current-limiting control exits. According to the invention, the amplitude limiting of the fault current in the fault ride-through of the network-constructed converter can be realized, so that the fault ride-through capability and transient stability of the network-constructed converter are improved.

The embodiment of the invention provides a transformer loss monitoring method and a transformer loss monitoring system, and the monitoring method comprises the steps: dynamically updating winding resistance, excitation reactance and iron core magnetic conductivity according to an electromagnetic parameter and a temperature parameter in a state vector space through employing a complex frequency domain parameter identification algorithm which introduces a fusion expansion Cole-Cole model; the no-load loss and the load loss are decoupled through an improved all-electric difference method, the dynamically updated excitation reactance and the iron core magnetic conductivity are used for decoupling the no-load loss, and the dynamically updated winding resistor is used for decoupling the load loss; and taking the decoupled loss data and the associated parameters in the state vector space as the input of an LSTM-Transform hybrid model loaded on the edge calculation module, and predicting and outputting the load loss trend in the future time period. According to the transformer loss monitoring method, the real-time performance, the accuracy and the adaptability of transformer loss monitoring are improved.

The invention relates to a circularly polarized quasi-absorption filtering phased-array antenna. A unit of the antenna comprises a multi-layer dielectric substrate, a semi-cured layer, a metal floor, a stacked patch and an orthogonal H-shaped gap, the first dielectric substrate is provided with a parasitic square loop, the second dielectric substrate is provided with a cross-shaped strip, and radiation zero points are introduced to the upper and lower edges of a passband respectively; the 3dB orthogonal directional coupler and the L-shaped feeder form a feed network, circularly polarized radiation is realized through slot coupling, and an isolation port of the 3dB orthogonal directional coupler is connected with a 50-ohm resistor, so that the energy of a lower stop band is absorbed, the energy of an upper stop band is reflected, and a quasi-absorption filtering characteristic is presented; the antenna is compact in structure and easy to process, has wide axial ratio bandwidth and good filtering performance, and when array scanning is 0-45 degrees, the overlapping impedance bandwidth is 12%, the axial ratio bandwidth is 15.8%, and the maximum scanning loss is 2.3 dB; the antenna is compact in structure and easy to process, has wide axial ratio bandwidth and good quasi-absorption filtering performance, and has huge potential in millimeter wave satellite communication application.

The invention relates to the technical field of thermistor temperature measurement, in particular to a temperature measurement detection device for a thermistor, which comprises a substrate and a handpiece, a to-be-measured resistor is mounted on the outer side wall of the substrate, an inner cylinder is fixedly connected to the end part of the handpiece, a top magnetic block is fixedly connected to the interior of the inner cylinder, and a top magnetic block is fixedly connected to the top magnetic block. A probe switching mechanism is arranged in the inner cylinder and comprises a rotating rod rotationally connected into the inner cylinder, a gear is fixedly connected to the outer side wall of the rotating rod, a push rod is slidably connected to the inner cylinder, and a rack is arranged at the end of the push rod. When an operator presses down the handheld piece, the swing arm can synchronously drive the two cleaning pieces to move towards the two sides, the cleaning brush directly cleans the surface of the resistor to be measured, extra manual cleaning is not needed, obstruction of dust residues to heat conduction is effectively avoided, and a precise foundation is laid for subsequent temperature measurement.

The heat accumulating type electric heater comprises a shell and a heat accumulator, a heat preservation and insulation layer is arranged on the inner side of the shell, the shell comprises a first shell section and a second shell section, and the shell is horizontal; the first shell section comprises an inlet section and a diffusion section, and the diffusion section is arranged to be in a conical shape. The diameter of the second shell section is larger than that of the inlet section. The two ends of the diffusion section are connected with the inlet section and the second shell section respectively. The heat accumulator is made of high-temperature-resistant alloy and provided with a plurality of heat exchange holes and heating holes, the heat exchange holes and the heating holes penetrate through the heat accumulator, heating units are arranged in the heating holes, and each heating unit comprises a resistance wire. According to the invention, gas flow heating is realized by adopting resistor direct heating and heat storage, the gas purity is high, and the test accuracy is good. The shell is of a horizontal structure, the length of an outlet pipeline can be reduced, temperature loss can be reduced, the defect that the temperature field is uneven due to the fact that the temperature of the upper portion of the heat accumulator is too high and the temperature of the lower portion is too low in the heat accumulation process can be overcome, and the temperature control precision reaches + / -1 DEG C.

The invention relates to the technical field of electric tool control, in particular to a motor control method of a target electric tool and a motor control circuit executing the motor control method, and the method comprises the steps: obtaining peak current at a detection resistor and a current PWM signal duty ratio, calculating real-time average current according to the peak current and the current PWM signal duty ratio, and comparing the real-time average current with an average current threshold value; and adjusting the duty ratio of the PWM signal according to the result, and outputting the PWM signal to drive the motor according to the adjusted duty ratio. By dynamically adjusting the duty ratio, the stability and safety of the electric tool under high load are effectively improved, the operation experience is optimized, the hardware upgrading requirement can be met, and the use bottleneck is broken through.

The utility model provides a directional coupler and a radio frequency chip, and relates to the technical field of electronic communication. The directional coupler comprises an input port, an output port, a coupling port, an isolation port and an impedance adjusting network, the impedance adjusting network comprises an access switch, an impedance adjusting module and an inductance unit. The impedance adjusting module comprises an adjustable resistor unit and an adjustable capacitor unit which are connected in parallel; one end of the impedance adjusting module is connected to the isolation port through the access switch, and the other end of the impedance adjusting module is connected to the inductance unit; wherein the inductance unit is used for compensating parasitic capacitance in the directional coupler. According to the scheme, the impedance matching and phase characteristics of the directional coupler can be adjusted according to different working frequencies and environmental conditions through mutual cooperation of the access switch, the impedance adjusting module and the inductance unit, so that the directional coupler can maintain good directivity under various working conditions.

The invention relates to the technical field of battery modeling and photovoltaic energy storage systems, and discloses a self-adaptive battery modeling method for direct current bus voltage support of an optical storage system. The method comprises the following steps: establishing a basic model comprising a direct-current voltage source, an ohmic internal resistor and an RC polarization network; the voltage drop depth is obtained by monitoring the voltage of the direct-current bus in real time and used for correcting the polarization resistance; and performing differential operation on the voltage to obtain a change rate so as to adjust the polarization capacitance. And dynamically optimizing the battery model by combining correction results of the two, and realizing adaptive updating of model parameters. And applying the optimization model to the optical storage integrated grid-connected system. The adaptability of the battery model to the dynamic working condition is improved.

The invention provides a fault indication device of a lightning arrester and the lightning arrester. The fault indication device comprises a target resistor, a low-melting-point alloy, a counterweight and a shell, the target resistor, the low-melting-point alloy and the counter weight are all located in the shell; the first end of the target resistor is connected with a shell of the lightning arrester, the second end of the target resistor is grounded, the upper end of the low-melting-point alloy is in fixed contact with the target resistor, and the lower end of the low-melting-point alloy is connected with the balance weight; the shell comprises a visual subarea at the bottom; the target resistor generates different heat according to the magnitude of the leakage current of the lightning arrester, and when the temperature of the target resistor is higher than the melting point temperature of the low-melting-point alloy, the low-melting-point alloy is melted, and the counterweight falls into the visual partition. According to the device, by triggering melting of the low-melting-point alloy, advanced visual early warning can be provided before the lightning arrester breaks down, and the problem that fault indication of the lightning arrester is not timely is solved.

The invention relates to a current measuring apparatus for redundant measurement of an electric current (I) with a low-resistance current measuring resistor (1) for current measurement according to the four-lead technique and with a magnetic field sensor (14). The invention provides that the electric current (I) to be measured in the current measuring apparatus is divided into a main current path with a main current (I1) and a secondary current path with a secondary current (I2), the main current path and the secondary current path together forming a parallel circuit. The low-resistance current measuring resistor (1) is arranged in the main current path and has the main current (I1) flowing through it, while the magnetic field sensor (14) is arranged in the secondary current path and measures the secondary current (I2).

The utility model relates to the technical field of energy storage power supplies, and mainly provides a direct-current power supply fault latch circuit and an energy storage system, the circuit comprises a switch module connected with a battery and a direct-current power supply, a latch module connected with the switch module, and a sampling resistor connected with the latch module, and the sampling resistor is also connected with the negative electrode of the battery and the negative electrode of the direct-current power supply. The switch module is also used for receiving the driving signal. The sampling resistor outputs a sampling voltage to the latch module according to the output current of the cathode of the DC power supply. The latch module is used for controlling the switch module to start working according to the driving signal when the sampling voltage is smaller than the preset voltage so as to output the power supply voltage of the battery to the direct-current power supply; and when the sampling voltage is greater than the preset voltage, it is considered that an overcurrent short circuit fault occurs, and at the moment, a turn-off signal is continuously output to the switch module to close the switch module and lock the closed state, so that output of the power supply voltage is stopped, and the service life of the energy storage system is prolonged while the energy storage system is protected.

The utility model relates to the field of resonance eliminators, and discloses a protection element and a current limiting type resonance eliminator, the protection element comprises at least two groups of protection units, the two adjacent groups of protection units are connected in series, and each protection unit comprises a protection module; the current-limiting resonance eliminator based on the current-sensitive resistor made of the current-sensitive material is connected in series between the PT neutral point and the ground. Under the normal operation condition, the current-limiting resonance eliminator is in a low-resistance state, and system parameters and PT performance are not affected; when excitation energy is generated due to a system fault, the current-limiting resonance eliminator suddenly changes into a high resistance state, quickly absorbs resonance energy, destroys resonance parameters, suppresses PT excitation current below 200mA, and ensures that a voltage transformer is unsaturated and a PT fuse is not fused; and a built-in current sensor is connected, so that the running state of the current-limiting resonance eliminator can be monitored in real time.

A low-profile ultra-wideband wide-angle scanning phased-array antenna based on a tight coupling structure is composed of a metal floor and a plurality of antenna units, the antenna units extend in the X polarization direction and the Y polarization direction respectively to form a plane of any size, and an antenna array is formed; the antenna unit sequentially comprises an upper substrate, a dipole antenna and a lower substrate from top to bottom, the dipole antenna is vertically and crossly placed and comprises two layers of dielectric substrates and a layer of prepreg between the two layers of dielectric substrates, and a resistor-coated pattern is printed on the upper surface of the lower substrate.

The metasurface array antenna housing comprises a plurality of array units of the same structure, each array unit sequentially comprises a first lightning protection layer from top to bottom, and each first lightning protection layer comprises four copper metal cylinders and a lightning protection top layer drainage metal patch; the second metasurface wave absorbing and transmitting layer comprises a first dielectric substrate, and four quasi-rectangular patches, four lumped resistors, four quasi-triangular patches and four quasi-square rings which are arranged on the upper surface of the first dielectric substrate; the third metasurface wave-transparent layer comprises a square metal patch, and a first circular ring and a second circular ring are etched on the square metal patch. Lightning is guided to the third metasurface wave-transparent layer through the first lightning protection layer, the lightning is conducted to other areas through the metal patch, damage of the lightning to the antenna housing is effectively avoided, and the antenna housing can directly replace a lightning protection strip for use; the structural size is greatly reduced, the angle stability is improved, and integration is facilitated; the copper-clad surface of the third metasurface wave-transparent layer can be used as a metal back plate of the second metasurface wave-absorbing layer, and structural multiplexing is achieved.

The present invention provides a DCDC converter using a dual-mode adaptive off-time timer, comprising: a PWM comparator, an on-time timer, a current detection module, an off-time timer logic control circuit, a drive control circuit, a dual-mode adaptive off-time timer, an inductor LOUT, an NMOS transistor MH, an NMOS transistor ML, a resistor RFB2, a resistor RFB1, and a capacitor COUT. The present invention is implemented by means of the PWM comparator, the on-time timer, the current detection module, the off-time timer logic control circuit, the drive control circuit, and the dual-mode adaptive off-time timer. The off-time of the internal dual-mode adaptive off-time timer has the function of adaptively adjusting an input signal and an output feedback signal, and a minimum off-time timer and an overcurrent off-time timer are simultaneously implemented by using one off-time timer.

The invention discloses an interference suppression measurement method for a grounding resistor, and relates to the technical field of interference resistance, and the method comprises the steps: injecting a detection current into a grounding electrode, and synchronously collecting an original voltage signal at two ends of the grounding electrode and a time domain waveform of the detection current; performing time domain segmentation on the original voltage signal, performing linear frequency modulation wavelet transform on the signal in each time period, generating an initial time-frequency matrix, extracting a time-frequency ridge line from the initial time-frequency matrix, identifying interference information, obtaining an interference-removed time-frequency matrix, optimizing the interference-removed time-frequency matrix through robust kernel principal component analysis, and obtaining an interference-removed time-frequency matrix; a synchronous redistribution operator is used for carrying out signal purification, a pure time-frequency matrix is obtained, linear frequency modulation Z transformation is carried out on the pure time-frequency matrix, voltage amplitude and frequency are extracted, an energy centroid method is used for correcting the voltage amplitude and frequency, interference can be effectively restrained, and the grounding resistance measurement precision is remarkably improved.

The invention discloses an energy storage type SOP black-start method, system and device based on improved VSG network construction control and a medium, and relates to the field of power grid black-start, and the method comprises the steps: an energy storage type converter MMC carries out the active and reactive control based on an improved VSG network construction control strategy; a non-fault side MMC is controlled to firstly close an isolation circuit breaker and slowly charge a direct-current capacitor, and when the voltage reaches a set threshold value, a current-limiting resistor is quitted; the fault side MMC is started by the same step as the non-fault side MMC; after synchronization is completed, AC circuit breakers between the non-fault side MMC and the feeder load and between the fault side MMC and the feeder load are closed respectively; based on the collected power grid power data, MMC output parameters are adjusted to meet the power grid connection condition, the control mode is switched according to the grid connection state, and the black start process is ended. And by arranging the black start resistor for current-limiting charging and sub-module voltage balance control, the phenomena of overcurrent and voltage unbalance in the black start process are avoided.

The invention belongs to the technical field of vehicle-mounted power supplies, and particularly relates to a driving circuit of a safety switch of a low-voltage battery, a low-voltage battery power supply system and a vehicle power system, and the driving circuit comprises a driving module, a reference end of which is used for being connected with a source electrode of the safety switch and is grounded; one end of the driving resistor is connected with the output end of the driving module, and the other end is connected with the grid of the safety switch; one end of the limiting capacitor is connected with the other end of the driving resistor, and the other end of the limiting capacitor is connected with the drain electrode of the safety switch or grounded; wherein the capacitance value of the limiting capacitor at least exceeds the capacitance value of a parasitic Miller capacitor of the safety switch with the preset first multiplying power, so that the grid current of the safety switch is limited, and the Miller plateau area of the safety switch is prolonged. The Miller platform area of the safety switch is prolonged, so that the drain current iD of the safety switch can charge the inner side capacitor in an approximate constant current mode, triggering of a reverse over-current fault is prevented, and charging of the inner side capacitor cannot be interrupted.

The invention discloses a lightning arrester resistor disc nonlinear conductivity fitting method and system based on a temperature correction coefficient, a medium and equipment, and the method comprises the steps: calculating a current-voltage relation of a lightning arrester according to the volt-ampere characteristic of the lightning arrester and the actual size and material parameters of each component in the lightning arrester, and converting the current-voltage relation into a current density-electric field intensity relation; processing the volt-ampere characteristic interpolation curve in a segmented manner by adopting a logarithm domain processing method and fitting the volt-ampere characteristic interpolation curve; calculating a nonlinear conductivity temperature correction coefficient according to the direct-current reference voltage of the resistor disc of the lightning arrester at different temperatures; calibrating the reference point of the temperature correction coefficient to obtain an equivalent nonlinear conductivity curved surface based on the temperature correction coefficient; performing goodness-of-fit calculation on the obtained equivalent nonlinear conductivity curved surface, and if the goodness-of-fit is relatively high, outputting the equivalent nonlinear conductivity; and if the goodness of fit is relatively low, performing segmentation fitting on the volt-ampere characteristic curve again until the goodness of fit of the equivalent nonlinear conductivity curved surface is relatively high.

The embodiment of the invention discloses a high-resistance grounding fault active line selection method, device and system, relates to the technical field of power distribution network relay protection, and aims to solve the problems of low sensitivity and poor reliability of high-resistance grounding fault line selection. The method comprises the following steps: when fault starting is monitored, controlling a switch assembly connected with a damping resistor in a neutral point grounding loop to act so as to change the access state of the damping resistor; collecting bus zero-sequence voltage and zero-sequence current of each feeder line before and after the action of the switch assembly; calculating the zero-sequence active power variation of each feeder line before and after the action; and finally, comparing the zero-sequence active power variation of each feeder line to determine a fault feeder line. According to the invention, excitation is actively injected and the power variation is analyzed, so that the fault characteristics are enhanced, and the method has the beneficial effects of high sensitivity and high reliability.

The utility model discloses a soft start system based on excitation current reduction, which is characterized in that a time relay mainly controls the switching of a live wire between a power resistor and an alternating current contactor, the power resistor magnetizes a transformer at the moment of electrification, and the alternating current contactor is connected into a circuit by the time relay after the magnetization is completed; and after the power resistor is short-circuited, the circuit is cut out, so that the purpose of suppressing the excitation inrush current is finally achieved, the excitation effect caused by voltage abrupt change at the power-on moment of the isolation transformer can be avoided, and the excitation abrupt change of the isolation transformer during power-on is effectively reduced.

The invention provides an optical sensing measurement method based on closed-loop adjustment of LED driving, and relates to the technical field of optical sensing. The method comprises the following steps: initializing a system; the microcontroller reads a current value of the analog-to-digital converter and calculates an error; calculating a new set value of the driving current of the light emitting diode according to the error; the microcontroller outputs the new set value to the digital-to-analog converter, the digital-to-analog converter controls the driving circuit to adjust the driving current of the light emitting diode, and after a preset time period, the current value of the analog-to-digital converter is collected; repeating the steps, when the error absolute value is smaller than a preset threshold value, judging that closed-loop convergence occurs, and recording the driving current at the moment and the current value of the analog-to-digital converter as measurement results; and obtaining the sample concentration according to the calibration curve and the driving current in the measurement result. According to the scheme, the dynamic range and the low-concentration precision are remarkably improved, LED aging and temperature excursion are inhibited, the circuit is simplified, and multiple groups of current-limiting resistors and multi-gear change-over switches are not needed.

The invention relates to the technical field of offshore wind power, in particular to a middle-long distance offshore wind power low-frequency combined power transmission system and an operation mode thereof, and the system comprises an M3C converter and a control system thereof, an M3C converter operation state change-over switch group, and an M3C converter energy consumption switch and an energy consumption resistor R1; the motor and generator coaxial M-G equipment and a control system thereof, an M-G equipment operation state change-over switch group, and an M-G equipment energy consumption switch and an energy consumption resistor R2; through switching of an M3C converter operation state change-over switch group, an M3C converter energy consumption switch, an M-G equipment operation state change-over switch group and an M-G equipment energy consumption switch, multiple operation states including at least maintenance, cold standby, hot standby, connection, operation and energy consumption are realized, and switching among the operation states is realized according to the access condition of a power grid and new energy. The method can provide stable supporting capacity for a power grid, and helps to solve the problems of offshore wind power integration and efficient absorption.

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.