174 results about "Harmonic interference" patented technology

The invention relates to the field of electric meter box monitoring, and discloses an anti-electricity-stealing method and system for an intelligent electric meter box, which is used for solving the problem of false alarm caused by harmonic interference when anti-electricity-stealing early warning is carried out, and comprises the following steps: collecting time domain signals of current and voltage in the intelligent electric meter box in a historical detection time period; converting the time domain signal into a frequency domain signal, extracting harmonic information of each harmonic, and establishing a normal harmonic feature model to obtain a target harmonic range; the method comprises the following steps: acquiring time domain signals of current and voltage in an intelligent electric meter box in real time, extracting harmonic information, performing filtering processing according to a target harmonic range, performing first abnormality judgment by using an abnormality detection algorithm, performing multi-parameter joint evaluation if abnormality is judged for the first time, and performing second abnormality judgment according to a multi-parameter joint evaluation result. And electricity larceny early warning is carried out according to the second abnormal judgment result, so that false alarm and missing alarm are effectively reduced, and the adaptability of the system to a complex electricity larceny mode is remarkably enhanced.

The invention discloses a dual-electric brake boosting system, which belongs to the technical field of vehicle brake control and comprises the following steps: S1, dynamically calculating quadrature-axis inductance parameters, generating a synchronous magnetic field signal and inhibiting electromagnetic interference of dual motors; s2, extracting a harmonic-rotating speed mapping relation, and dynamically correcting an observation equation to control a parameter error; s3, reconstructing neutral point voltage to counteract high-frequency jitter, and reducing residual harmonic interference through adaptive filtering; s4, establishing a three-dimensional thermal field to predict copper and iron loss, dynamically adjusting current and generating an inverse time limit protection curve; s5, splitting the hot parameters into parity check frames, optimizing a communication protocol and compressing a refresh cycle to 10ms; s6, overlapping response of the white noise excitation system, and performing closed-loop calibration on the filtering weight to improve the observation precision; s7, triggering an audible and visual alarm and synthesizing a directional voiceprint and a tactile pulse to ensure safety regulations and perception intensity; the method has the beneficial effects that the method has remarkable advantages in a high-temperature and high-vibration severe environment, and the reliability and the safety of a system can be improved.

The invention relates to an AI server cooling water pump vibration quantity self-adaptive calibration test method and system, an intelligent test platform integrates a six-dimensional force sensor and a temperature compensation vibration exciter, the platform rigidity is automatically calibrated, a water pump-pipeline system transfer function is obtained, and a rotating speed-lift-modal frequency three-dimensional mathematical model is established; a three-axis MEMS accelerometer array is arranged at sensitive parts such as a water pump bearing seat and a motor shell, and vibration, current and pressure signals are synchronously collected; carrying out time-frequency domain signal processing by adopting variational mode decomposition in combination with self-adaptive S transformation, and extracting a 128-dimensional full-frequency domain feature vector containing a modulation side frequency band; effective values of vibration acceleration, speed and displacement are calculated through a frequency domain integration algorithm, and current harmonic interference is corrected through an electromagnetic vibration compensation model; and finally, a vibration health degree evaluation model containing 18 characteristic parameters is established based on a support vector machine, the test system comprises an intelligent test platform unit, a multi-source sensing unit, an edge calculation unit and a data management unit, and microsecond-level synchronous acquisition and GB-level data throughput are realized through a time sensitive network. And online incremental learning and automatic generation of a test report are supported. The method has the effect of improving the water pump vibration quantity test precision.

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 electric leakage detection alarm method and system for a distribution box. The method comprises the steps of collecting zero-sequence current signals of all branches; dividing a fundamental wave region, a low-frequency harmonic region and a high-frequency harmonic region, and calculating the energy ratio of each frequency band; identifying higher harmonic interference based on the high-frequency energy ratio; a load type is determined through an equipment identification module, and a zero-sequence current tolerance interval is generated in combination with a preset model; according to the invention, the zero-sequence current tolerance model associated with the equipment type is constructed, the equipment identification module and the model generation module are combined, and the dynamic zero-sequence current tolerance interval is generated according to the information of the equipment type, the rated parameter, the grounding mode and the operation cycle, and is used as an important basis for judging whether the electric leakage behavior belongs to a normal working condition or not. When the actual detection value is in the tolerance interval, even if the zero-sequence current level is high, the system can correctly identify the state as a non-fault state, so that the problem of false alarm or alarm dead zone is avoided.

The invention relates to the technical field of motor regulation and control, in particular to a dust collector motor vibration noise reduction method and system, and the method comprises the steps: obtaining a sinusoidal modulation electric signal generated by a sinusoidal pulse width modulation frequency converter, and carrying out the harmonic filtering of the sinusoidal modulation electric signal, and obtaining a higher harmonic; calculating harmonic interference magnetomotive force according to the higher harmonics, multiplying the harmonic interference magnetomotive force by the air gap magnetic conductance to obtain radial magnetic flux density, and calculating radial electromagnetic force waves; performing feature extraction operation on the radial electromagnetic force wave to obtain a feature set, performing principal component analysis operation based on vibration intensity to obtain a radial vibration principal component feature set, and performing noise principal component harmonic extraction operation on the higher harmonic according to the radial vibration principal component feature set to obtain a noise harmonic; and performing noise reduction calculation on the sinusoidal modulation electric signal according to the noise harmonic wave to obtain a noise reduction modulation electric signal, and performing power control on the motor. The vibration noise of the dust collector motor can be reduced.

The invention relates to the technical field of power system court management, and particularly discloses a court identification and user binding method based on a special transformer acquisition terminal, which comprises the following steps: separating harmonic interference generated by start and stop of an electric welding machine through a kurtosis index and time-frequency energy entropy fusion detection method, and extracting a fundamental voltage and a pure power signal; constructing a dynamic time bending model containing phase consistency and gradient feature constraint based on the fundamental wave voltage, and calculating voltage track similarity to judge electrical coupling; for the users with electrical coupling, dynamic weight power cross-correlation analysis is fused to generate a comprehensive decision value, and a space-time diagram neural network is utilized to update a transformer area topology structure online in combination with a historical topology change event, so that the dynamic determination of the transformer area to which the users belong is realized; through multi-dimensional feature fusion and anti-interference algorithm design, the problems of phase deviation and waveform distortion caused by electric welding machine harmonic waves are reduced, and the transformer area identification accuracy and real-time performance are improved.

The invention relates to the technical field of on-line monitoring, in particular to an insulation fault on-line monitoring method and system for a medical IT system control cabinet. The method comprises the following steps: selecting a non-integer frequency multiplication detection frequency according to equivalent ground distributed capacitance in a previous monitoring period, and superposing the non-integer frequency multiplication detection frequency with a fundamental frequency to form a composite signal injection system; collecting signals to calculate a voltage instantaneous harmonic distortion rate change gradient, and selecting a time window to split the leakage current according to the change gradient; on the basis of dispersion estimation signal-to-noise ratio weighted fusion current vectors, insulation resistance and distributed capacitance are calculated; constructing a four-dimensional original feature vector composed of the insulation parameter, the phase difference and the intermodulation component energy; constructing a diagonal weighting matrix based on the resistance-capacitance ratio and the gradient to transform a feature vector, and determining the fault attribution through the Mahalanobis distance calculation with the fault template library. According to the scheme, harmonic interference can be avoided, calculation stability can be improved, insulation instantaneous sudden change can be quickly responded, and different fault types can be accurately distinguished to guide maintenance.

The invention provides a hysteresis loop analysis method for a transformer no-load loss test, and belongs to the technical field of transformers. Exciting voltage and current signals are collected in a transformer no-load state, and an active filter is used for carrying out digital filtering processing to eliminate harmonic interference; a data corresponding relation between magnetic flux density and magnetic field intensity is established through a digital integration algorithm and a magnetic field intensity calculation formula to form original hysteresis data, the original hysteresis data is processed by using a hysteresis loop optimization model, a complete hysteresis loop curve is generated, and the hysteresis loop area is calculated. According to the hysteresis loop area, the hysteresis loss power density is calculated through the iron loss calculation function, the total value of the transformer no-load loss is obtained by combining the eddy current loss calculation result, and the technical problems that the hysteresis loop reconstruction precision is not high and the complex hysteresis phenomenon cannot be adapted in the transformer no-load loss test are solved.

The invention relates to the technical field of harmonic wave evaluation, and particularly discloses a follow-up network parallel system harmonic wave anti-interference evaluation method and system considering frequency coupling, and the method comprises the steps: obtaining grid-connected current data of a GFL converter and a GFM converter under different background harmonic waves, calculating the harmonic wave coupling admittance matrix of the GFL converter and the GFM converter, and calculating the harmonic wave coupling admittance matrix of the GFL converter and the GFM converter; obtaining a harmonic coupling admittance matrix of the parallel system at the common coupling point; calculating a power grid side harmonic coupling admittance matrix based on the harmonic coupling admittance matrix of the parallel system at the common coupling point and the power grid line impedance; and based on the power grid side harmonic coupling admittance matrix, calculating an evaluation index of the anti-background harmonic interference capability of the parallel system, and realizing evaluation of the harmonic anti-interference capability of the parallel system. According to the method, harmonic mutual impedance is introduced, the influence of harmonic coupling is fully considered, and the harmonic anti-interference capability evaluation precision is effectively improved in part of scenes.

The present invention provides a broadband harmonic suppression power amplifier containing a resistive filter, and relates to the technical field of power amplifiers. The present invention effectively solves the power supply compatibility problem between BJT power units and GaN power units through innovative single-power intelligent reconstruction technology. Ensure that the negative gate voltage required by the GaN power unit is established first and intelligently triggers the drain power supply, reducing the risk of device damage caused by bias disorder. The built-in resistive filter network and cascade control design can adaptively suppress high-frequency harmonic interference, improve signal purity and system electromagnetic compatibility. Through modular circuit integration, while retaining the original power supply interface and heat dissipation structure, the seamless upgrade from BJT to GaN architecture is achieved, reducing the cost and cycle of hardware transformation. Supporting seamless switching of dual-mode power units, the operating frequency range of old equipment is expanded and the output power is enhanced without the need for overall reconstruction, while reducing overall energy consumption.

The invention discloses a rotating machinery fault diagnosis method based on frequency domain adaptive Kaiser convolution window Fourier transform, which comprises the following steps: constructing a frequency domain adaptive Kaiser window function for an acquired discrete vibration signal containing multi-harmonic fault information, and reducing the influence of frequency aliasing in different frequency domain intervals; a frequency domain adaptive Kaiser convolution window model is established by applying self-convolution operation, and the influence of spectrum leakage and noise interference is reduced; calculating the Fourier transform of the signal based on an adaptive Kaiser convolution window, establishing a time-frequency (IKTF) model of an improved Kaiser window base, and carrying out model solution calculation to obtain the time-frequency distribution of the signal; and determining selection of frequency domain adaptive parameter values, and identifying fault characteristic frequency information in time-frequency distribution. According to the innovative method, the weak fault features of the rotating machinery can be extracted, and the influence of factors such as background noise, harmonic interference and random impact is effectively overcome, so that the accuracy of fault detection is improved.

The invention belongs to the technical field of motor control, and particularly relates to a current harmonic suppression method based on a generalized active disturbance rejection controller. Comprising the following steps: S1, establishing a permanent magnet synchronous motor current loop mathematical model containing disturbance, and constructing a d-axis current equation and a q-axis current equation containing disturbance by taking respective current components of a d-axis and a q-axis as state variables; s2, defining the lumped disturbance of the d axis and the q axis as an extended state variable, and constructing an extended state observer to estimate the lumped disturbance; s3, constructing an improved resonance controller; and S4, establishing an active-disturbance-rejection control law, feeding back the lumped disturbance estimated in the step S2 to the active-disturbance-rejection control law for aperiodic disturbance compensation, and expanding the improved resonance controller in the step 3 and embedding the expanded improved resonance controller into the active-disturbance-rejection control law for periodic harmonic compensation. According to the invention, harmonic interference generated in the operation process of permanent magnet synchronization can be suppressed, so that the robustness of a motor control system is improved.

The invention relates to an interference signal offset method and device, equipment and a storage medium, and the method comprises the steps: carrying out the sampling of an original input signal, obtaining a single-frequency signal, carrying out the multiple iteration of a weight coefficient of the single-frequency signal through a notch filtering device, and determining a target weight coefficient, and simulating the harmonic interference signal according to the single-frequency signal and the target weight coefficient, and generating an analog interference signal to offset the harmonic interference signal in the original input signal. Therefore, the harmonic interference signal is simulated in a mode of determining the weight proportion of the component through the analog component, and the interference signal in the original input signal is subjected to background processing after the analog interference signal is generated, so that the extraction accuracy of the sine wave signal is improved.

The invention discloses a radio frequency switch circuit with a cross feedback structure, a chip and electronic equipment. According to the radio frequency switch circuit, through the innovative cross feedback structure, the excellent technical effect is achieved, and particularly, the radio frequency switch circuit has outstanding performance in the aspects of high power bearing capacity and high harmonic processing capacity. Body end connecting diodes of the main circuit and the branch circuit are completely separated from source ends and drain ends of switching transistors in respective circuits, so that internal connection is fundamentally avoided, a nonlinear effect caused by parasitic diodes can be effectively reduced, and harmonic distortion is reduced. Therefore, the radio frequency switch circuit not only has high power bearing capacity, but also can bear large voltage fluctuation and maintain definition and accuracy of communication signals; the radio frequency switch circuit also has high harmonic wave processing capability, can effectively reduce harmonic wave interference caused by high-power signals, and meets strict requirements of a wireless communication system on the radio frequency switch circuit.

The invention discloses a zinc oxide arrester aging fault monitoring method and system based on fifth harmonics, and belongs to the technical field of high-voltage electrical equipment protection. The method comprises the following steps: acquiring the total leakage current of the zinc oxide arrester under different applied voltages; the different applied voltages comprise pure sine wave voltages and voltages with harmonic components; according to the total leakage current, obtaining leakage resistance current and third harmonic and fifth harmonic thereof; comparing the total leakage current, the leakage resistance current, the third harmonic and the fifth harmonic to obtain a monitoring index of the aging fault of the zinc oxide arrester; and obtaining a monitoring result of the aging fault of the zinc oxide arrester according to the monitoring index of the aging fault of the zinc oxide arrester and the applied voltage. According to the invention, the harmonic component is added into the applied voltage to simulate the harmonic interference of the power grid voltage, and the leakage current of the lightning arrester is analyzed to monitor whether the aging fault of the zinc oxide lightning arrester occurs.

The invention discloses a power distribution network reliability intelligent analysis method and analysis system, particularly relates to the technical field of power system fault detection, and is used for solving the problems of misjudgment and missed judgment caused by fault feature weakening and harmonic interference in a bidirectional power flow scene in an existing method. The method comprises the following steps: firstly, synchronously collecting fundamental wave and harmonic components of nodes of a power distribution network, extracting a current amplitude change rate and a phase offset by adopting time-frequency domain conjoint analysis, and generating dynamic distribution characteristics by combining harmonic energy clustering; identifying high-frequency interference components in a bidirectional power flow mode by quantizing a phase deviation direction and harmonic energy aggregation characteristics; based on a harmonic frequency band coupling effect and a current dynamic association relationship, an adaptive detection threshold function is constructed, and accurate separation of fault features is realized; and finally, combining a real-time fault judgment result with historical repair data to generate a reliability evaluation parameter. And the sensitivity of fault detection and the rationality of reliability evaluation in a complex operation environment are remarkably improved.

The invention discloses an electric energy meter based on a self-adaptive observer and a using and collecting terminal frequency estimation method. The method comprises the following steps: setting an initial value for a first intermediate variable estimation value; continuously sampling the voltage or the current to obtain sampling data and adding the sampling data into a cache; when a group of sampling data is newly added into the cache, calculating a calculated value of a second intermediate variable corresponding to the new sampling data based on the new sampling data, then obtaining a gradient value based on the calculated value of the second intermediate variable, and calculating a new first intermediate variable estimated value based on the gradient value and the current first intermediate variable estimated value; if the continuously obtained first intermediate variable estimates have converged, an estimate of the frequency is calculated based on the current first intermediate variable estimate. According to the method, frequency estimation can be carried out once after each sampling point is obtained, the frequency estimation speed is greatly improved, and high estimation precision can still be achieved on the occasion with large harmonic interference.

The invention relates to the technical field of electrical safety, and particularly discloses an arc fault protection method based on a circuit breaker intelligent algorithm, which comprises the following steps: S1, collecting a line current signal in real time, eliminating harmonic interference of a frequency converter from an original signal through an anti-aliasing filter, and converting the original signal into a digital signal; s2, processing the current signal by adopting a three-stage cascade wavelet analysis module, and outputting a dynamic peak-to-average ratio to S4; s3, detecting current disturbance based on a double-slide-rail window, outputting a disturbance positioning mark and a time-frequency feature to S4, judging a disturbance event, and positioning a starting point; s4, receiving the dynamic peak-to-average ratio of the S2 and the disturbance positioning mark and the time-frequency characteristics of the S3, performing path processing according to a characteristic analysis result, and adopting a direct interruption method and an electromagnetic radiation-current frequency domain cross validation method; s5, constructing an electric arc energy accumulation prediction model; according to the invention, the problems of weak arc leak detection, electromagnetic interference maloperation and delay are solved.

The invention belongs to the technical field of power electronics, and particularly discloses a phase-locked loop based on multistage filtering and compensation and a control method. According to the invention, the method comprises the steps: firstly collecting the voltage when a power grid is unbalanced or abnormal, then obtaining the d-axis and q-axis components of a positive sequence, a negative sequence, a third harmonic and a fifth harmonic through the positive and negative sequence separation, then designing a high-pass filter to filter out the negative sequence, the third harmonic and the fifth harmonic, and finally carrying out the amplitude and phase compensation of the filtered d-axis and q-axis components. And the information is sent to a traditional phase-locked loop for phase locking control, so that more accurate power grid phase information can be quickly obtained. According to the invention, under the conditions of unbalanced power grid voltage, harmonic interference and phase and frequency abrupt change, interference signals of third and fifth harmonics can be filtered out only by designing a set of filtering and compensation parameters, the phase locking speed is not slowed down while the phase locking precision is improved, and in practical application, the application has a wide application prospect. The method has the advantages of high dynamic response speed, simple parameter design, high reliability and the like.

The invention discloses a transformer fault diagnosis method, system and equipment based on harmonic injection and a storage medium, and the method comprises the steps: installing a vibration sensor on a transformer body, collecting steady-state and dynamic vibration signals, and carrying out the preprocessing of the vibration signals; time domain feature analysis is carried out on the collected vibration signals, frequency domain feature analysis is carried out on the vibration signals, and then spectrum complexity is analyzed; normal ranges of RMS values, peak factors and odd-even harmonic ratios are set through historical data, and if the data exceed the set ranges, the fan influence is further analyzed; analyzing in combination with a power system operation mode, and then performing fault judgment based on a machine learning classification algorithm; if the direct current magnetic bias is detected, an HVDC operation mode is adjusted; and if harmonic injection is detected, an active harmonic filter is adopted to suppress harmonic interference. The harmonic current is detected and compensated in real time, the voltage and current waveforms of the power grid are improved, the harmonic pollution of the power grid is reduced, and the electric energy quality is improved.

The invention provides a thyristor commutation turn-off control method and system based on harmonic interference self-adaptive regulation and control, and relates to the technical field of data processing.The method comprises the steps that the current operation state of a thyristor is detected, initial data related to turn-off of the thyristor is obtained, and an original turn-off data set is formed; calculating an expected commutation voltage value according to the original turn-off data set, and generating a commutation trigger signal in combination with an external harmonic interference parameter; adjusting an inductance value and a capacitance value in a commutation loop according to the commutation trigger signal; when the commutation operation is executed, the change trend of the anode-cathode voltage of the thyristor is monitored in real time, and the inductance value of the commutation loop is finely adjusted according to the change trend; when the change trend of the anode-cathode voltage of the thyristor rises rapidly and is stable, the turn-off is completed; dynamic parameter data in the turn-off process are collected and stored, and a thyristor turn-off report is generated; according to the invention, the autonomy and accuracy of the turn-off of the thyristor are improved.

The invention discloses an electromagnetic collaborative simulation control system and method for a multi-chip and packaging system, and relates to the technical field of electromagnetic collaboration, and the method comprises the following steps: setting an initial electromagnetic simulation frequency domain range according to the working frequency range of a target system; according to the invention, the electromagnetic co-simulation control system extracts key characteristics such as multi-signal channel nonlinear crosstalk intensity and impedance resonance offset, and the harmonic change coefficient generated by machine learning is combined, so that the nonlinear interference and resonance mismatch influence of higher harmonics on the system can be accurately quantified. The system dynamically adjusts a simulation frequency domain range, classifies and identifies normal and abnormal processes, effectively captures higher harmonic interference of key frequency bands, avoids resource waste, improves simulation efficiency and system reliability, and realizes efficient and accurate electromagnetic analysis.

The invention discloses a vibroseis synchronous excitation method and device, and relates to the technical field of seismic exploration, and the method comprises the steps: loading a plurality of frequency division scanning signals into different vibroseis for many times, obtaining a plurality of vibroseis groups, and enabling the vibroseis in each vibroseis group to be in one-to-one correspondence with the frequency division scanning signals; the plurality of vibroseis groups are controlled to sequentially excite and scan in the target area according to a first time interval threshold value, the plurality of vibroseis in each vibroseis group are synchronously excited, and the excitation time interval of different vibroseis groups is the first time interval threshold value; the first time interval threshold value is determined according to the harmonic interference degree between different frequency division scanning signals and the first distance threshold value; performing correlation processing by using the seismic data acquired by each vibroseis group and the synthesized reference signal to obtain a plurality of correlated seismic single shot data; and the synthetic reference signal is formed by vertically superposing and synthesizing a plurality of frequency division scanning signals. According to the invention, the seismic data aliasing noise can be reduced.

The invention provides a frequency interference processing method, electronic equipment and a storage medium, and the method comprises the steps: obtaining the current working frequency band information and current signal state information of a baseband communication module in a target communication chip, and obtaining the current working frequency and frequency information of a memory in the target communication chip; according to the current working frequency band information and the frequency information, a non-interference frequency library corresponding to the memory is determined, and the non-interference frequency library comprises at least one non-interference frequency; and determining a target working frequency of the memory according to the non-interference frequency library, the current working frequency and the current signal state information. The problem that the sensitivity of the baseband communication module is interfered by the harmonic of the memory is solved.

The utility model belongs to the technical field of electronic circuit, especially relates to a passive low harmonic frequency converter special for rail transit air conditioner. The frequency converter includes: passive filter module, rectifier module, precharge module, voltage-sharing filter module, inverter module and control module. The input end of passive filter module is connected to the output end of alternating -current source, and the output end is connected to the input end of rectifier module, and the output end of rectifier module is connected to the input end of precharge module, the output end of precharge module is connected to the input end of voltage-sharing filter module, the output end of voltage-sharing filter module is connected to the input end of inverter module, and the output end of inverter module is the voltage output end of passive low harmonic frequency converter special for rail transit air conditioner, and inverter module and control module are connected through inverter control and protection circuit. The utility model can reduce the harmonic interference of frequency converter inverter to input power grid, protects the electrical equipment on power grid, and improves the security of operation.

The application relates to a high-voltage power-taking capacitor protection and harmonic suppression system and a circuit thereof, and belongs to the field of power distribution network intelligent control switch power taking. The circuit is arranged between an isolation transformer and a feeder terminal unit (FTU), and comprises an input protection circuit for suppressing input surge overvoltage and fast pulse group, a harmonic filter circuit for filtering out harmonics, a signal acquisition and conditioning circuit for converting an alternating current signal into a direct current voltage signal, and a control protection circuit for comparing the direct current voltage signal with a preset reference voltage. The system further comprises a high-voltage capacitor voltage divider, an isolation transformer and the feeder terminal unit (FTU). The application effectively solves the problem that harmonic interference, surge impact and overvoltage risk coexist in the high-voltage power-taking system, greatly improves the safety and reliability of the operation of the rear-end FTU equipment under the premise of ensuring the accuracy of voltage signal measurement and power supply continuity.

A multi-harmonic, multi-channel, global active vibration control method for helicopters involves constructing independent bandpass tracking filter banks to separate the harmonic components in the acceleration response error signal at each control point on the helicopter's fuselage. Each harmonic component is independently controlled by selecting a convergence factor. During the control process, the reference input signal is reconstructed while updating the weights of the Fx-LMS adaptive controller with global vibration minimization as the control objective. This method achieves significant attenuation of the acceleration response at all measurement points on the helicopter's fuselage under multi-harmonic interference from the helicopter's rotor blades, effectively improving the vibration level of the fuselage. The present invention separates and independently controls the fundamental and harmonic components of the vibration signal by constructing several independent adaptive filters, with global vibration minimization as the control objective, to update the controller weights.

The invention discloses an operation control method and system of a direct-drive motor, and relates to the technical field of control of the direct-drive motor, and the method comprises the steps: collecting three-phase voltage fluctuation data in real time, extracting a harmonic spectrum in combination with frequency domain analysis, preliminarily estimating the conduction delay and dead-zone compensation time, and increasing dead-zone compensation to form a preliminary optimization parameter when low-order harmonics exceed the standard; and then neutral point deviation, common-mode voltage and three-phase asymmetry degree are evaluated through waveform simulation, finally, a swarm intelligence optimization algorithm is adopted to iteratively adjust a potential balance correction coefficient, conduction delay, dead zone compensation and an interphase time sequence deviation angle to obtain a target time sequence parameter, and a three-phase switch control instruction is generated to be applied to a control system. According to the invention, in the control of the high-power direct-drive motor, the harmonic interference is effectively reduced by optimizing the time sequence design of the switching action, meanwhile, the system risk caused by potential imbalance is avoided, and the operation stability and reliability of equipment are improved.

The application relates to the technical field of direct current transmission systems, in particular to a direct current transmission system operation risk optimization method based on multi-dimensional analysis, wherein the direct current transmission system comprises a rectifier and an inverter, and the specific method comprises the following steps: performing harmonic interference risk assessment on the rectifier; performing power quality risk assessment on the inverter based on the result of harmonic risk control optimization; calculating inverter risk quality indexes based on the result of the power quality risk assessment; and performing inverter risk compensation optimization based on the inverter risk quality indexes. The application realizes the risk assessment of harmonic interference in the rectification process and the power quality risk assessment of the inversion process after interference control optimization, and further realizes more accurate assessment of the operation risk of the direct current transmission system, effectively solving the problem that the harmonic interference risk in the rectification process and the power quality risk in the inversion process are insufficiently related in the prior art.