121 results about "High frequency oscillation" patented technology

The invention relates to a DC power transmission system oscillation suppression method based on a matrix passivity theory. The method comprises the following steps: firstly, establishing a converter admittance matrix under a frequency coupling effect; then, constructing a stability criterion of the direct-current power transmission system based on the admittance matrix of the converter in combination with a matrix passivity theory; and finally, based on the stability criterion of the direct-current power transmission system, adding active damping and passive damping, adjusting corresponding parameters, and suppressing medium-high frequency oscillation of the direct-current power transmission system. The method can solve the problem of dependence on power grid side impedance modeling, constructs the stability criterion of the DC power transmission system by directly analyzing the admittance matrix characteristics of the converter, adapts to the complex situation when the AC grid side operation condition changes, and can completely suppress the medium-high frequency oscillation of the DC power transmission system. An unstable interval of a direct current system is transferred to a high frequency band through active damping, strict stability of the direct current power transmission system in middle and high frequency bands is achieved through passive damping, and the strategy cost is reduced.

The embodiment of the invention discloses a negative damping elimination method, device and equipment based on SVG and a storage medium, and the method comprises the steps: carrying out the impedance scanning of the SVG in a range of 1-3000Hz, obtaining the positive-sequence impedance and negative-sequence impedance of the SVG under different operation conditions, and determining the leading operation condition of the SVG impedance; determining the positive sequence equivalent impedance and the negative sequence equivalent impedance of the SVG grid-connected point according to the positive sequence dominant impedance and the negative sequence dominant impedance of the SVG under the dominant operation condition; determining the value ranges of the positive sequence damping correction value and the negative sequence damping correction value of the SVG; the maximum value of the intersection of the two value ranges is determined as SVG compensation damping, and the SVG compensation damping is merged into an SVG grid-connected point port; according to the scheme, only two unknown parameters including the positive sequence damping correction value and the negative sequence damping correction value are involved, the parameters can be calculated based on an analytic formula pure algebraic equation, the calculation mode is simple, the port impedance characteristic negative damping of the SVG in the full frequency band within the range of 1-3000 Hz can be eliminated, and the problem of high-frequency oscillation is thoroughly solved.

The invention discloses a servo connecting rod high-frequency swing mechanism, which belongs to the technical field of bearing processing equipment, and comprises an adjusting piece and a swing head which are arranged on the same side outside a bracket, one end of the transmission shaft is connected with the adjusting piece; one end of the swinging shaft is connected with the swinging head; the two ends of the connecting rod are eccentrically arranged relative to the transmission shaft and the swing shaft respectively and rotationally connected with the adjusting piece and the swing head respectively; the adjusting piece is used for adjusting the eccentric distance of the connecting rod relative to the transmission shaft in the radial direction. The belt link is omitted through direct-drive transmission, the servo motor coupler directly drives the transmission shaft, power loss is reduced, and the swing frequency and stability are improved.

The invention discloses an FCE diode and a manufacturing method thereof. The cathode metal is provided with a trench isolation region, cathode N + regions and cathode P + regions, the cathode N + regions and the cathode P + regions are transversely and alternately arranged, the trench isolation region isolates the cathode N + regions from the cathode P + regions, and the thickness of the trench isolation region exceeds 2 microns of the cathode N + regions and the cathode P + regions And then a plasma storage region, a field stop region, a base region, an anode P region and anode metal are sequentially arranged. The thickened trench isolation region is indispensable for improving the current density uniformity near the cathode, and can weaken low-frequency oscillation and reduce conduction voltage drop; the thickened plasma storage region can weaken low-frequency oscillation, improve the current density uniformity near the anode and reduce reverse recovery energy under severe or extreme conditions; the two measures can also ensure that the base region is greatly thinned on the premise of enlarging the safe working region, so that the loss is reduced. By optimizing and compromising the structural parameters of each area, the FCE diode can achieve the beneficial effects of self-clamping, low loss, uniform current density, no high-frequency oscillation, slight low-frequency oscillation and wide safe working area.

The invention discloses a random question number generator and method suitable for a question and answer mode watchdog, and belongs to the technical field of integrated circuit safety. Comprising an on-chip high-frequency oscillation source, an enabling controller, a low-power-consumption controller, a pseudo-random number generator and a random code hopping device. According to the method, an external dog feeding signal is used for triggering, a non-reproducible hopping code value is generated by using different sources of clock sources and physical deviation of signal transmission, a pseudo-random number generator is controlled to operate within a random duration, and a low-power-consumption state is entered after a final random problem number is output and latched. Through hardware-level entropy source enhancement and dynamic power consumption management, the predictable potential safety hazard of the traditional pseudo-random number sequence is fundamentally solved, and the balance of high randomness, high attack resistance and low power consumption is realized at low cost.

This invention discloses a method for locating epileptogenic zones based on high-frequency oscillations and connectivity, comprising the following steps: 1. Acquiring SEEG data and selecting representative channels; 2. Filtering to acquire 54-200Hz signals and selecting baseline and target data; 3. Acquiring normalized high-frequency energy; 4. Calculating time and energy coefficients to obtain a high-frequency epileptogenicity index; 5. Filtering to acquire 12-45Hz signals; 6. Calculating nonlinear regression analysis; 7. Calculating total intensity; 8. Defining and calculating the connectivity high-frequency epileptogenicity index and evaluating performance. This invention can accurately locate epileptogenic zones in patients with different seizure patterns, and has potential application value in epilepsy treatment.

The present invention comprises: a high-frequency oscillator that transmits high-frequency energy and includes a control unit; a high-frequency connecting line connected to the high-frequency oscillator; and a high-frequency transmission pad connected to the other end of the high-frequency connecting line and attached to the curve of facial skin in close contact with it, wherein the high-frequency transmission pad is configured such that an adhesive pad and a bipolar pad are integrated or separate. This invention relates to a non-invasive automatic facial lifting device using high-frequency energy that adheres closely to the curves of the face to be treated, thereby enabling uniform delivery of high-frequency energy to the skin, allowing for effective treatment without separate operation, minimizing the risk of excessive thermal damage to specific areas of the skin, resolving issues such as pain, scarring, and infection associated with existing invasive technologies, enhancing user convenience and safety through an automated control system and customized settings, and providing uniform treatment effects and reducing treatment time and fatigue by monitoring skin temperature in real time and delivering high-frequency energy according to set output, time, and patterns.

The invention relates to a core temperature sensor (CTS) for use with a microwave cooking appliance that generates microwaves within a specific microwave frequency band for cooking food, wherein the core temperature sensor (CTS) comprises: at least one temperature sensor (TS), an antenna (ANT), a high-frequency oscillator (1) whose output signal can be fed into the antenna (ANT) and whose signal frequency lies outside the microwave frequency of the microwave cooking appliance, a modulation device (OOK) configured to generate a pulse train from the output signal of the high-frequency oscillator (1) by means of amplitude modulation, which corresponds to digital temperature data generated by means of the at least one temperature sensor (TS), and an electrical energy storage device (BAT) for supplying electrically operated components (MCU, TS, OSZ-AMP) of the core temperature sensor (CTS).The invention also relates to a system comprising a core temperature sensor and a cooking device, comprising a receiver for receiving electromagnetic waves emitted by the core temperature sensor and a control device configured to operate the cooking device based on information contained in the received electromagnetic waves.

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.

The invention discloses a ship propeller underwater cleaning robot and a cleaning method, and relates to the technical field of ship cleaning. The cleaning and recycling mechanism comprises a sweeping and recycling device and an ultrasonic cleaning device which are connected to the robot body; the ultrasonic cleaning device is used for beating dirt on the surface of the propeller through high-frequency oscillation signals to loosen the dirt; the sweeping and recycling device comprises a mechanical arm, a scrubbing assembly and a recycling and filtering assembly. The scrubbing assembly is connected to the tail end of the mechanical arm and used for cleaning dirt on the propeller. The recycling and filtering assembly is connected to the scrubbing assembly and can suck dirt for collection and filter water flow and then return the water flow to a water source; the power system comprises a propeller assembly, and the propeller assembly is connected to the robot body and used for propelling the robot body to reach the cleaning position; the posture detection system comprises a main controller, an IMU chip sensor, a camera and a laser range finder which are connected to the robot body.

The invention relates to the technical field of combustors, in particular to a TPMS porous medium combustor and a two-way air inlet using method thereof.The TPMS porous medium combustor comprises a combustor body and a TPMS porous medium heat accumulator filled in the combustor body, air inlet pipes which are symmetrically arranged are fixed to the two sides of the combustor body, and the ends of the air inlet pipes are fixedly communicated with premixing pipes; the air supply pipes are symmetrically fixed to the side wall of the premixing pipe, and an airflow adjusting assembly is arranged on the premixing pipe and used for adjusting the flow speed of airflow pumped by the air supply pipes; the partition plate is fixed in the air inlet pipe, and the partition plate divides the air inlet pipe into a buffer chamber and a conveying chamber; the conveying pipe is fixed to the air inlet pipe and communicates with the conveying cavity and the combustor, and a communicating assembly is arranged in the air inlet pipe; and the buffer pushing mechanism is arranged in the air inlet pipe, and when the air pressure in the buffer cavity is gradually increased, the conveying pipe can be controlled to be gradually conducted through a conduction assembly, so that high-frequency oscillation caused by air pressure fluctuation is avoided.

The invention discloses a high-frequency oscillation suppression method and system for a flexible direct-current power transmission system, and belongs to the field of high-frequency oscillation suppression of a power system, and the method comprises the steps: adding a Gaussian white noise signal in current control of the flexible direct-current power transmission system, and continuously observing the voltage and current of a grid-connected point of the flexible direct-current power transmission system; acquiring the amplification factor of the oscillation signal in the frequency domain and the oscillation stabilization time in the time domain, and judging the current oscillation risk; when the oscillation risk exists, a differential first controller is introduced to compensate a selected current loop feedback signal, a positive torque signal is generated, and parameters of the differential first controller are obtained based on the current oscillation risk level; and performing feedforward compensation on the generated positive torque signal to an output link of a flexible converter in the flexible direct-current power transmission system. The negative damping phenomenon caused by the control delay effect is effectively compensated, and high-frequency oscillation of the flexible direct-current power transmission system is avoided.

The application discloses a tobacco cut tobacco variable frequency motor state monitoring method based on a common mode loop and belongs to the motor state monitoring field. In view of the problem that early-stage faults of insulation deterioration of a variable frequency motor are difficult to detect in a high-dust, high-humidity and strong electromagnetic interference environment of a tobacco cut tobacco workshop, the application utilizes the correlation characteristics between a common mode loop signal and a motor insulation state, firstly establishes a common mode loop impedance model considering a common mode inductance of a stator winding, an inter-turn equivalent capacitance and a stray capacitance to ground, and calculates a common mode loop resonance frequency; then high-frequency oscillation loop models and medium-frequency oscillation loop models are respectively constructed to obtain an analytical relationship between a common mode current oscillation frequency and an insulation capacitance; a variational mode decomposition algorithm is adopted to separate multi-frequency oscillation characteristics in the common mode current, and high-frequency and medium-frequency common mode oscillation frequencies are extracted; and through online monitoring of an oscillation frequency drift amount, the deterioration degree of phase terminal insulation and internal insulation to ground of the motor winding is evaluated in real time. The application realizes non-invasive online precise monitoring of early-stage insulation faults of the tobacco cut tobacco variable frequency motor, and effectively reduces the risk of unplanned shutdown of a cut tobacco production line.

This utility model discloses a handheld laser welding device, which includes a metal gun body with an alumina ceramic nozzle and a high-frequency oscillation circuit, a rectifier filter circuit, an electronic switch circuit, and an MCU disposed within the gun body and connected in sequence. The high-frequency oscillation circuit is electrically connected to the metal gun body so that when the alumina ceramic nozzle approaches the metal workpiece, a switch signal is transmitted to the MCU through the high-frequency oscillation circuit, the rectifier filter circuit, and the electronic switch circuit. The MCU is used to turn the gun body on or off according to the switch signal. In this application, since the internal circuit has no electrical connection with the metal workpiece being welded, it has strong anti-interference ability, and the nozzle does not need to contact the workpiece, resulting in a longer service life.

A low noise block-downconverter system (LNB system) includes a local oscillator module having first and second phase locked loop circuitry (PLL circuitry) for downconverting an electrical signal to generate a downconverted signal. The first PLL circuitry receives a low-frequency reference signal that is used with an intermediate-frequency oscillator to generate an intermediate-frequency signal. The second PLL circuitry receives and uses the intermediate-frequency signal in conjunction with a high-frequency oscillator, separate from the intermediate-frequency oscillator, to generate a high-frequency signal. The high-frequency signal is used to downconvert the electrical signal. The signal dynamic range of the first PLL circuitry is higher than the signal dynamic range of the second PLL circuitry, thus achieving improved overall dynamic range for the LNB system. The first PLL circuitry may be a first integrated circuit defining a low phase-noise amplifier. A second integrated circuit may include the second PLL circuitry and the high-frequency oscillator.

The invention discloses a resonance network for suppressing transient recovery voltage of a circuit breaker, and belongs to the technical field of high-voltage alternating-current circuit breaker switching-on and switching-off. The resonance network is composed of a metal oxide arrester and N resonance branches with the same structure. The number N of the resonant branches and the resonant frequencies of the resonant branches are obtained through an electromagnetic transient simulation model; the resonant frequency presents low impedance near the transient recovery voltage fundamental frequency, a shunt and energy consumption path is provided for the high-frequency oscillation current, and active suppression of the rising gradient and the oscillation amplitude of the transient recovery voltage is achieved. The metal oxide lightning arrester is used as backup protection, and clamps the transient recovery voltage peak value when the suppression effect of the resonance branch is insufficient or abnormal. The resonant network can significantly suppress the rise rate and amplitude of transient recovery voltage under a high voltage level in a medium strength recovery critical period, effectively improves the on-off reliability of the vacuum circuit breaker, and has good working condition adaptability and system safety.

The utility model relates to vacuum coating equipment technical field especially is concerned about a kind of device of high-frequency oscillation auxiliary magnetron sputtering preparation DLC film, including vacuum sputtering cavity, vacuum system and gas delivery system, the vacuum system and gas delivery system are communicated with the inner chamber of vacuum sputtering cavity respectively, the inside of vacuum sputtering cavity is equipped with magnetron sputtering assembly, high-frequency oscillation auxiliary assembly and substrate turret assembly, plasma channel is formed between the magnetron sputtering assembly and substrate turret assembly, the high-frequency oscillation auxiliary assembly includes oscillation coil and the high-frequency oscillation power supply of oscillation coil electrical connection, the oscillation coil is set to the region corresponding plasma channel in vacuum sputtering cavity inside, the utility model breaks through the ionization limit of traditional magnetic field by introducing high-frequency oscillation field to strengthen the collision excitation of electron and particle, provides feasible path for preparing high-performance DLC film, and its technical research and development and application have important significance to break through industry bottleneck.

The invention belongs to the technical field of LED driving power supplies, and particularly relates to an intelligent power-saving driving power supply module for LED lighting, which comprises a high-frequency oscillator used for emitting a high-frequency signal with the oscillation frequency of 63.2 KC; the high-frequency amplifier is used for receiving the high-frequency signal sent by the high-frequency oscillator and amplifying the high-frequency signal; the high-frequency pulse generator is used for receiving the high-frequency signal amplified by the high-frequency amplifier and converting the amplified high-frequency signal into a high-frequency pulse according to a time ratio; the high-frequency pulse width adjusting controller is used for receiving the working characteristic curve of the LED lamp bead, adjusting the pulse width of the high-frequency pulse output by the high-frequency pulse generator according to the working characteristic curve of the LED lamp bead, and synchronously inputting the high-frequency pulse output by the high-frequency pulse generator and a driving power supply into the LED lamp bead; compared with a traditional LED driving power supply module, the power saving rate of the device can reach 40% under the technical conditions that voltage and power are not adjusted and original illuminance is not influenced.

To provide an atomic oscillator that can be miniaturized and manufactured on-chip while keeping costs down. [Solution] The atomic oscillator 10 detects the light transmitted through the gas cell 8 and the gas cell 8 containing alkali metal atoms to generate an electrical signal S LI A photodetector 9 converts the signal S to a high-frequency oscillator 31 using an FBAR. LI The input is a feedback signal S. FB A control circuit 1 outputs a feedback signal S FB The control circuit 1 further includes a laser light source 6 that outputs modulated light and introduces it into the gas cell 8, and a control circuit 1 further includes a variable capacitor 32 that adjusts the oscillation frequency of the high-frequency oscillator 31, and a high-frequency adjustment signal S tune The frequency converter 41 outputs the signal S output by the high-frequency oscillator 31. OUT The high-frequency adjustment signal S tune The system includes a frequency mixer 42 that mixes the gas with the gas and outputs a signal at a frequency that synchronizes with the resonant frequency of the gas cell 8.

The invention provides a fire hazard wind field and spread dynamic prediction method and system based on radar echo evolution characteristics. The method comprises the following steps: step 1, carrying out ground clutter suppression, radial high-frequency oscillation filtering, speed deblurring and time-space consistency check on reflectivity Z, radial speed V, spectral width W and dual polarization quantity of a plurality of weather radars; 2, under a three-dimensional variational 3DVAR framework, taking a numerical mode background field as prior, and performing inversion to obtain a boundary layer three-dimensional wind field; 3, establishing an anisotropic cellular automaton (CA) and live wire particle swarm coupling model under the constraints of a digital elevation model (DEM), combustible material types, water content and meteorological elements; 4, performing real-time correction and short-term and temporary extrapolation on the fire point and live wire states; and step 5, result output and early warning. By applying the technical scheme, the minute-level short-term and temporary prediction capability can be improved, and the safety of key assets such as power transmission channels is ensured.

The invention relates to a core temperature sensor (KTF) for use with a microwave cooking appliance which generates microwaves within a specific microwave frequency band in order to treat food to be cooked, the core temperature sensor (KTF) having: at least one temperature sensor (TS); an antenna (ANT); a high-frequency oscillator (1), the output signal of which can be fed into the antenna (ANT) and the signal frequency of which lies outside the microwave frequency of the microwave cooking appliance; a modulation device (OOK), which is designed to generate a pulse sequence from the output signal of the high-frequency oscillator (1) by means of an amplitude modulation process, said pulse sequence corresponding to digital temperature data (OST) generated by means of the at least one temperature sensor (TS); and an electric energy storage device (BAT) for supplying electrically operated components (MCU, TS, OSZ-AMP) of the core temperature sensor (KTF). The invention also relates to a system having a core temperature sensor and a cooking appliance, having a receiver for receiving electromagnetic waves emitted by the core temperature sensor and a control device which is designed to operate the cooking appliance on the basis of information contained in the received electromagnetic waves.

The present invention relates to an electrically adjustable, multi-frequency, multi-beam, stand-alone antenna comprising: a first electromagnetic lens, a second electromagnetic lens, a mounting plate, a reflector plate, oscillator units A1 to A32, oscillator units B1 to B8, and phase shifters C1 to C12. The first and second electromagnetic lenses are both cylindrical lenses. Oscillator units A1 to A32 operate at a higher frequency than oscillator units B1 to B8. The first electromagnetic lens, the second electromagnetic lens, the reflector plate, and the mounting plate are fixed together. Oscillator units A1 to A32 and oscillator units B1 to B8 are all mounted on a reflective surface of the reflector plate. Phase shifters C1 to C12 are all mounted on the mounting plate.Each set of four high-frequency oscillators and each set of two low-frequency oscillators are connected to a phase shifter. The present invention is characterized by a simple structure, scientific design, small size, flexible beam direction configuration, etc.

The utility model discloses a road surface thickness detection device, and belongs to the field of road construction, the road surface thickness detection device comprises two symmetrically arranged support frames, the bottoms of the support frames are provided with walking mechanisms, the exteriors of the support frames are provided with support mechanisms, and the sides, away from the support mechanisms, of the support frames are provided with protection mechanisms. A height adjusting mechanism is arranged in the supporting frame, a moving rod is arranged outside the height adjusting mechanism, a detection antenna, a high-frequency oscillator, a receiving antenna and a signal amplifier are arranged, electromagnetic waves with specific frequency are generated through the high-frequency oscillator, and then the electromagnetic waves are sent to the position above the road surface by a certain distance through the detection antenna. The reflected electromagnetic wave signal is received by the receiving antenna, and the received weak signal is amplified by the signal amplifier, so that the subsequent analysis of the weak signal is facilitated by the data processing module, the problems that the traditional pavement thickness detection method is long in time consumption, high in labor intensity and easy to be influenced by personal errors are solved, and the practicability is improved.

The invention discloses an active yaw control method of a multi-impeller floating type wind generating set and related equipment. The active yaw control method comprises the steps that the incoming flow wind direction and the real-time azimuth angle and the motion state of a floating type platform are monitored in real time or periodically; filtering or state estimation processing is carried out on the real-time azimuth angle of the floating platform to filter out high-frequency oscillation components induced by waves, and an estimated azimuth angle reflecting the average yaw attitude of the floating platform is obtained; determining a target azimuth angle of the floating platform according to the incoming flow wind direction, and calculating a deviation angle between the estimated azimuth angle and the target azimuth angle; when the deviation angle exceeds a preset threshold value, according to the deviation angle and the environmental disturbance influence, generating a rotating torque control instruction used for driving the floating platform to rotate around the single-point mooring system; according to the rotation torque control instruction, at least one propeller installed on the floating type platform is controlled to generate thrust so as to drive the floating type platform to rotate till the deviation angle is reduced to be within a preset threshold value. The invention aims to realize quick, accurate and cooperative yaw control in the multi-impeller floating type fan, avoid the adoption of a complex and heavy independent yaw mechanism and inhibit the influence of wave disturbance on the yaw precision.

The invention relates to the technical field of civil engineering square pile forming, and discloses square pile forming equipment for municipal civil engineering, which comprises a die bed, and is characterized in that a square pile forming mechanism is arranged at the top of the die bed, and a moving assembly is arranged outside the square pile forming mechanism; a concrete pouring mechanism, a concrete fluidization mechanism and a concrete finishing mechanism are sequentially arranged in the moving assembly in the moving direction, a cooperative control system is installed outside the square pile forming mechanism, the moving assembly comprises a portal frame, and the portal frame is installed on the outer side of the square pile forming mechanism. According to the invention, controllable high-frequency oscillation generated by the high-frequency vibrator is conducted by using the vibrating reed, so that a shear thinning phenomenon of a concrete material is generated, and the concrete material enters a fluidized state in a local area, so that the concrete material is uniformly and compactly arranged in a mold; and the problem of local defects of the square pile caused by non-uniform distribution of concrete materials is avoided.

This utility model relates to the field of desktop high-frequency machine technology, and discloses a desktop high-frequency machine for slipper production, including a machine body. A cabinet is installed on the top of the machine body, and a low-frequency generator is fixedly installed on one side of the cabinet. A mounting base is installed inside the cabinet, and a transistor is installed on the top of the mounting base. This desktop high-frequency machine for slipper production generates low-frequency alternating current through the low-frequency generator. Using electron tubes and transistors, the low-frequency alternating current is converted into high-frequency alternating current. The acceleration and deceleration of electrons in the electric field form a high-frequency oscillating current, which is transmitted to a waveguide and then released as electromagnetic waves to the shoe mold above. The electromagnetic waves penetrate the entire shoe mold, accelerating its shaping. The support frame directly fixes the waveguide below the sliding frame, reducing losses during electromagnetic wave release. The sliding frame allows for easy removal and replacement of the shoe mold from inside the cabinet.

The invention discloses a driving circuit of a switching tube, a motor and a range hood, and belongs to the technical field of power electronics. The driving circuit of the switching tube comprises a driving chip used for generating a driving signal; the first end of the first impedance element is used for being electrically connected with a driving chip; the input end of the filtering unit is connected with the second end of the first impedance element, the output end of the filtering unit is used for being electrically connected with the driving end of the switching tube, and the filtering unit is configured to restrain alternating current components in the driving signal. According to the driving circuit of the switching tube, the first impedance element can be used as a driving resistor of the switching tube, and the filtering unit which is in a resistance state for an alternating current signal is connected in series between the driving resistor and the driving end of the switching tube, so that a high-frequency impedance path can be provided for high-frequency oscillation current excited in a high-speed switching process; high-frequency oscillation energy excited by a high-speed switch of a switching tube is attenuated, and the amplitude of the high-frequency oscillation energy is suppressed, so that electromagnetic interference generated by disturbance power is reduced.

The invention discloses a filtering method and system for suppressing high-frequency oscillation of a flexible direct current converter, and the method comprises the steps: arranging a band elimination filter in an inner loop current controller of the flexible direct current converter, and carrying out the filtering of the high-frequency oscillation of the flexible direct current converter when the high-frequency oscillation of the flexible direct current converter and an alternating current power grid connected with the flexible direct current converter is detected; the center frequency of the band elimination filter is adaptively adjusted based on the high-frequency oscillation frequency and the high-frequency oscillation type of the flexible direct-current converter, so that the impedance characteristic of the flexible direct-current converter can be effectively enhanced in a high-frequency band, and high-frequency oscillation suppression of the flexible direct-current converter is realized. And the multi-frequency-point oscillation problem caused by different alternating-current power grid operation modes can be solved.

The invention discloses an intelligent piezoelectric beam vibration suppression control method based on a fuzzy improved active disturbance rejection controller. Firstly, a kinetic model and a state-space equation of the intelligent piezoelectric beam are established; thirdly, according to the state-space equation of the intelligent piezoelectric beam, constructing a fuzzy improved active-disturbance-rejection controller, including designing a nonlinear Arcfu function based on an arctan function, and constructing an extended state observer and a nonlinear state error feedback control law based on the nonlinear Arcfu function; the fuzzy controller generates a deviation increment of the vibration displacement tracking error and the vibration speed tracking error according to the deviation of the vibration displacement tracking error and the vibration speed tracking error, and dynamically adjusts a control law parameter by using the deviation increment; finally, the vibration displacement of the intelligent piezoelectric beam is obtained in real time, the fuzzy improved active disturbance rejection controller generates system control quantity according to the vibration displacement, the system control quantity acts on the piezoelectric ceramic piece, and active vibration suppression control is conducted on the intelligent piezoelectric beam. According to the method, high-frequency oscillation is avoided, and the vibration suppression control effect is enhanced.