54 results about "Modulation effect" patented technology

The invention discloses an electromagnetic field simulation method under the coupling action of tidal waves and sea waves. The method comprises the steps that input parameters of the tidal waves and the sea waves are set; configuring environmental parameters and geomagnetic conditions; superposing the tidal wave velocity field and the sea wave disturbance velocity field to form a total velocity field; the tidal wave part and the sea wave part are linearly coupled in time and space to obtain a tidal wave-sea wave coupling field evolved along with a tidal phase; in the tidal wave-sea wave coupling field, electromagnetic response calculation is executed on each frequency-direction sampling point; general field synthesis and modulation effect analysis: introducing a tidal wave modulation factor to clearly reflect amplitude periodic change and spectrum reconstruction characteristics of an electromagnetic field signal along with a tidal phase; and outputting a time sequence, an amplitude spectrum and a spatial distribution result of the comprehensive electromagnetic field. According to the method, the authenticity and applicability of sea wave induction electromagnetic field simulation can be improved, and a new technical means is provided for electromagnetic noise recognition, sea wave parameter inversion and complex ocean dynamics process research.

The invention relates to the technical field of bridge load tests, and provides a bridge load test crack increment change observation method and system, and the method comprises the steps: collecting prestressing tendon circumferential strain distribution data and dual-wavelength strain response data; calculating an interface bonding stiffness change parameter; pre-stress modulation effect compensation and polar coordinate system conversion are carried out on the strain response data and the rigidity change parameters, and micro-crack characteristic signals are obtained; load data and beam group arrangement parameters are collected, and a micro-crack propagation prediction model is established in combination with the interface bonding stiffness change parameters; inputting the micro-crack characteristic signal into a micro-crack propagation prediction model, and outputting a micro-crack development trend prediction result; and adjusting sampling parameters of a dual-wavelength time division multiplexing algorithm and characteristic extraction parameters of prestress modulation effect compensation according to a micro-crack development trend prediction result. According to the invention, the precision of observing the increment change of the micro-crack in the bridge load test is improved, and the automatic monitoring and prediction of the micro-crack of the prestressed concrete bridge are realized.

The invention provides a plasma transient time boundary-based terahertz wave spectrum regulation and control method and device, and the method comprises the steps: obtaining femtosecond laser and terahertz waves, and enabling the femtosecond laser and the terahertz waves to enter a terahertz wave transmission space through beam combination; when the femtosecond laser and the terahertz wave synchronously pass through a first position point, the terahertz wave after frequency spectrum regulation and control is obtained; the first position point is located in the terahertz wave transmission space, a time boundary caused by medium transient refractive index sudden change is formed at the first position point when the femtosecond laser ionizes gas to obtain plasma, and frequency shift occurs when terahertz waves pass through the time boundary. According to the invention, the modulation effect on the terahertz wave frequency demand can be realized according to the abrupt change of the refractive index caused by the transient generation of the plasma.

The invention discloses a method and system for detecting the magnetization direction of an unmagnetized magnet, and belongs to the technical field of magnetic material detection. The method comprises the following steps: applying an external guide magnetic field to a to-be-detected non-magnetized magnet; detecting a signal related to the physical state of the non-magnetized magnet under the action of the guide magnetic field as a response signal; and judging the magnetization direction of the non-magnetized magnet based on the corresponding relation between the response signal and the preset magnetization direction. The corresponding system comprises a guide magnetic field generation unit, a detection unit and a discrimination unit. The modulation effect of magnetocrystalline anisotropy of a non-magnetized magnet on an external magnetic field is utilized, invisible magnetic domain orientation information is converted into externally observable physical field difference, efficient, visual and lossless recognition of the preset magnetization direction is achieved, and the method is suitable for production quality control of magnetic assemblies such as a Halbach magnetic circuit and the like.

The embodiment of the invention discloses a background Alpha rhythm-based audio-visual perception ability evaluation method, which comprises the following steps of: acquiring an individual Alpha peak frequency of each subject, and setting various background rhythm stimuli for each subject; enabling each subject to execute various audio-visual perception tasks while the various background rhythms are stimulated, so as to collect electroencephalogram data and behavior data of each subject when the various audio-visual perception tasks are executed under the stimulation of the various background rhythms; performing feature extraction on the electroencephalogram data of each subject to obtain electroencephalogram features; performing feature extraction on the behavior data of each subject to obtain behavior features; screening electroencephalogram features related to improvement of the behavior features from the electroencephalogram features to obtain effective electroencephalogram features; and based on the effective electroencephalogram characteristics of each subject under the individual Alpha rhythm stimulation and the effective electroencephalogram characteristics of each subject under each contrast rhythm stimulation, calculating the modulation index of each subject so as to quantitatively evaluate the adjustment effect of the individual Alpha rhythm stimulation on the audiovisual perception ability of each subject.

This application discloses an optical communication wavelength meter based on lithium niobate microcavity optical comb-excited rubidium atom two-photon transitions, comprising a microcavity optical comb module, a repetition frequency phase-locked loop (PLL), an initial frequency PLL, a rubidium atom gas cell, and a frequency-stabilized light source. The microcavity optical comb module generates a fundamental frequency optical comb and a frequency-doubled optical comb to directly excite rubidium atom two-photon transitions. The frequency-stabilized light source achieves frequency stabilization through rubidium atom saturation absorption. The repetition frequency PLL adjusts the repetition frequency based on the error signal of the two-photon transition fluorescence intensity. The initial frequency PLL adjusts the initial frequency by feeding back the beat signal between the frequency-doubled optical comb and the frequency-stabilized light source. The two PLLs stabilize the microcavity optical comb to two sets of transition energy levels, achieving frequency locking between the repetition frequency and the initial frequency. The optical communication wavelength meter based on lithium niobate microcavity optical comb-excited rubidium atom two-photon transitions provided in this application avoids the cross-modulation effect in the joint adjustment mechanism of pump wavelength and pump power, reducing the size of the optical communication wavelength meter.

The application discloses a phase-amplitude decoupling modulator for complex amplitude modulation, which comprises at least a first modulation layer, a second modulation layer and a phase-amplitude decoupling modulator, wherein the phase-amplitude decoupling modulator comprises a controller, a first excitation module and a second excitation module; the first excitation module inputs independent excitation signals to the first modulation pixel unit; and the second excitation module inputs independent excitation signals to the second modulation pixel unit. The application breaks through the shackles of low amplitude-phase modulation level, mutual restraint of phase-amplitude modulation effect, complex preparation process and the like, and can realize independent and multi-order amplitude modulation and phase modulation for complex amplitude complete information reconstruction, so that the resolution, amplitude distribution uniformity, precision, signal-to-noise ratio and other performances are improved, and the dynamic switching of images and the improvement of reconstructed image quality are completed.

The invention relates to the technical field of data exception processing, in particular to a causal reasoning analysis method for data system exception access. Comprising the following steps: acquiring a temperature sensitive parameter of a hardware capacitor in a data system, a hidden offset parameter of a software process priority and a frequency drift parameter of environmental electromagnetic radiation; establishing a first coupling relationship between the hardware capacitor temperature sensitive parameter and the software process priority hidden offset parameter, wherein the first coupling relationship reflects the nonlinear influence of the hardware capacitor temperature change on the software process scheduling period; constructing a second coupling relationship between a software process priority recessive offset parameter and an environment electromagnetic radiation frequency drift parameter based on the first coupling relationship, wherein the second coupling relationship reflects a modulation effect of software process resource preemption on an electromagnetic radiation source working duty ratio; according to the invention, the problem of insufficient low-probability abnormal event positioning capability caused by multi-factor coupling in the prior art can be solved.

The utility model discloses an SIP radio frequency surface-mounted BPSK modulator, which relates to the technical field of semiconductor radio frequency devices, and comprises a substrate and a phase-locked loop circuit arranged on the substrate, the phase-locked loop circuit is connected with a power divider and a differential buffer output unit, the power divider and the differential buffer output unit are connected with a modulation multiplier, and the modulation multiplier is connected with an SIP radio frequency surface-mounted BPSK modulator. The modulation multiplier is connected with a baseband processing unit and a first filter, the baseband processing unit is connected with a first signal input end, the first filter is connected with a switch modulation unit, the switch modulation unit is connected with a second signal input end and a second filter, and the second filter is connected with a signal output end. The device provided by the utility model has the advantages of small size, integration, multiple functions and good modulation effect.

A multi-core optical fiber and an acousto-optic modulation device. The multi-core optical fiber comprises: an acoustic-excitation core, a plurality of outer cores, a trench layer, and a cladding; the acoustic-excitation core is located at the circle center position of the cladding, and the distances between the acoustic-excitation core and the plurality of outer cores are equal; the trench layer is arranged on the outer side of the acoustic-excitation core; and the plurality of outer cores have the same core spacing and are annularly arranged around the acoustic-excitation core. By using the acoustic-excitation core, the multi-core optical fiber can simultaneously modulate a plurality of light-guiding cores within the cladding, achieving consistent modulation effects.

The invention relates to the technical field of digital pre-distortion, in particular to an adjacent multiband digital pre-distortion system and method, and the method comprises the steps: S1, extracting an intermodulation feature vector of an adjacent multiband input signal, and constructing a nonlinear coupling feature matrix based on the intermodulation feature vector; and S2, generating a frequency band cooperative compensation signal by using the nonlinear coupling characteristic matrix, wherein the frequency band cooperative compensation signal is used for compensating an asymmetric cross modulation effect between adjacent frequency bands. And S3, constructing a dynamic pre-distortion parameter optimization model based on the distortion characteristic analysis result of the frequency band cooperative compensation signal and the power amplifier output signal, and generating a final pre-distortion output signal through real-time feedback adjustment. According to the method, the nonlinear primary function set including the high-order intermodulation item and the inter-band cross modulation component is constructed, and the nonlinear coupling feature matrix extracted by singular value decomposition is combined, so that inter-band collaborative modeling and compensation signal generation are realized, and the adaptive capacity under the complex working condition is enhanced.

The application provides a large-span tower lightning activity modulation detection method and system, relates to the field of lightning monitoring and protection, and solves the technical problem that it is difficult to accurately identify the modulation effect of towers on lightning activity under a detection method with small data volume and without relying on distribution assumptions; the method comprises the following steps: performing data processing on lightning event data to obtain sample set one and sample set two, calculating the distribution difference and the significance threshold of sample set one and sample set two in a three-dimensional space, and judging whether the tower construction has a modulation effect on lightning activity based on the distribution difference and the significance threshold; if yes, calculating the annual lightning density change rate and the lightning current amplitude median drift amount before and after the tower is put into operation in each concentric ring-shaped region, and performing smooth fitting to obtain a fitting curve; determining the modulation region and the corresponding spatial position parameters based on the fitting curve; and the application can improve the accuracy of identifying the modulation effect of large-span towers on lightning activity.

The application provides a large-span tower lightning activity modulation detection method and system, relates to the field of lightning monitoring and protection, and solves the technical problem that it is difficult to accurately identify the modulation effect of towers on lightning activity under a detection method with small data volume and without relying on distribution assumptions; the method comprises the following steps: performing data processing on lightning event data to obtain sample set one and sample set two, calculating the distribution difference and the significance threshold of sample set one and sample set two in a three-dimensional space, and judging whether the tower construction has a modulation effect on lightning activity based on the distribution difference and the significance threshold; if yes, calculating the annual lightning density change rate and the lightning current amplitude median drift amount before and after the tower is put into operation in each concentric ring-shaped region, and performing smooth fitting to obtain a fitting curve; determining the modulation region and the corresponding spatial position parameters based on the fitting curve; and the application can improve the accuracy of identifying the modulation effect of large-span towers on lightning activity.

The invention relates to the technical field of high and low voltage, and discloses a high and low voltage power distribution cabinet abnormal current intelligent modulation method, which comprises the following steps: respectively aiming at three phase sequences, obtaining real-time current sequences at multiple moments, analyzing current quality based on the real-time current sequences obtained by sampling, constructing a real-time current matrix according to the real-time current sequences, and calculating the abnormal current of a high and low voltage power distribution cabinet according to the real-time current matrix. And the current matrix is compared with a standard current matrix, so that whether the current is abnormal or not can be quickly and directly judged. According to the method, a standard current matrix and a real-time current matrix are differenced, and an abnormal current sample combination capable of forming an overall difference current matrix is searched in an abnormal current sample set according to a superposition principle, so that rapid abnormal current analysis can be realized, various abnormal current components can be extracted, and classification and modulation of the abnormal current can be realized. And meanwhile, a control signal is dynamically adjusted through an adaptive fuzzy control method, the abnormal current is dynamically modulated, the control signal is dynamically adjusted according to the modulation effect, and closed-loop control of the modulation process is achieved.

The invention relates to the technical field of motor health state diagnosis, and particularly discloses a motor health state diagnosis system based on multi-sensor fusion, which comprises a multi-source sensing acquisition module, a high-precision time synchronization module, a dynamic feature extraction module, a self-adaptive fusion decision module and a health state output module, according to the invention, a high-precision time synchronization module is constructed, and a strategy of combining hardware timestamp injection with phase offset estimation based on cross-correlation and rotation modulation compensation is adopted, so that time alignment of three kinds of heterogeneous signals of vibration, current and temperature at a sub-microsecond level is realized; the problem of feature space distortion caused by sensor sampling frequency difference and a mechanical rotation modulation effect under a high-speed working condition is fundamentally solved, and the space-time consistency of original data is remarkably improved.

The invention relates to the technical field of power system monitoring and load management, and particularly discloses a non-intrusive target load identification method based on cloud-end scene migration, which introduces a physical consistency data enhancement mechanism at a cloud end, and simulates a modulation effect of voltage sag on a background load by calculating a dynamic coupling modulation factor. And a high-fidelity enhanced triple data set is generated, so that the problem that the coupling characteristic of a circuit is neglected in traditional data enhancement is solved. On this basis, a brand invariance feature extractor is trained by using hierarchical metric learning, and class essential features are learned by optimizing an inter-class and inter-brand distance forced model. Finally, the feature extractor and the classification head are assembled into a generalization model to be deployed to the end side, reasoning is carried out by freezing parameters of the feature extractor, the cross-brand generalization problem caused by physical heterogeneity of the electric appliance is effectively solved, and accurate identification of the electric appliance with no brand at the end side is achieved.

This electromagnet structured to minimize spatial constraints comprises: an iron core composed of a body part for supporting the bottom, and a pair of head parts that protrude a predetermined length from both ends of the body part so as to face each other; and a pair of coil parts wound around the outer part of the iron core, wherein the head parts are formed in a polyhedral shape having a polygonal cross-section so that a magnetic field is formed in a space where the head parts face each other and the center position of the magnetic field varies in the vertical direction according to the shape of the surface where the head parts face each other.

The invention relates to an M3C low-frequency port modeling method, device, equipment and medium based on multi-frequency coupling, and the method comprises the steps: carrying out the non-single frequency multiplication sequence decomposition of voltage, current and modulation signals in an M3C bridge arm loop under a static coordinate system, extracting the steady-state component of each frequency component, and constructing an M3C steady-state frequency domain model; based on the model, analyzing frequency coupling characteristics of the power frequency component, the low frequency component and the circulating current component in the bridge arm current, and establishing a frequency-crossing conversion relation between the bridge arm current and the power frequency current, and between the bridge arm current and the low frequency current and the circulating current; based on the cross-frequency conversion relation, performing frequency domain modeling on the low-frequency side control signal, and establishing a low-frequency modulation small signal model; the modulation effect of a control loop is introduced, a bridge arm modulation small signal comprehensive model is established, equivalent coupling factors of power frequency power grid impedance and a low-frequency transformer are considered, and an admittance model of an M3C low-frequency port is deduced. The method has the effect of improving the judgment accuracy of the dynamic relation between the bridge arm current and the port voltage under the low-frequency and frequency doubling coupling condition.

The application relates to the technical field of integrated circuits, and discloses a hysteresis comparator circuit based on double-gate field effect tubes and an integrated chip, wherein the hysteresis comparator circuit comprises at least two cascaded inverters, each inverter comprising at least one input tube and one load tube, wherein the drain of the input tube and the source of the load tube are connected, and a connection node is configured as an output end of the inverter, and at least one of the input tube and the load tube of each inverter is a double-gate field effect tube; a feedback conductive wire is connected between the second gate of the double-gate field effect tube in the first-stage inverter and the output end of the other inverters, so that the signals on the first gate and the second gate of the double-gate field effect tube change in the same phase, to constitute positive feedback for realizing hysteresis effect. The application utilizes the common modulation effect of the two gates of the double-gate field effect tube to constitute the hysteresis effect, reduces the difficulty of on-chip integration of the hysteresis comparator, and improves the flexibility of the hysteresis comparator.

The present invention discloses an on-orbit directional pattern calibration method for a satellite-borne microwave scatterometer based on an active calibrator. The method comprises: obtaining the elevation angle and azimuth angle of the beam at different times within the scatterometer antenna system based on the position information of the active calibrator; obtaining the elevation angle and azimuth angle of the beam at different times within the active calibrator antenna system based on the pointing information and position information of the active calibrator; obtaining the data power received by the active calibrator at different times based on the power signal received by the active calibrator and the elevation angle and azimuth angle of the beam at different times within the active calibrator antenna system; and obtaining the antenna pattern of the scatterometer based on the data power received by the active calibrator at different times. The present invention solves the problem of directional pattern calibration under rapidly changing scatterometer antenna coordinate systems and compensates for the modulation effect of the active calibrator on the satellite-borne directional pattern, thereby improving the on-orbit test accuracy of the antenna pattern.

This invention discloses a laser device, a lidar, and a laser detection method. The laser device includes: a laser chip for generating a laser beam signal based on a driving signal; a beam signal transmission device disposed on the beam signal transmission path for splitting the laser beam signal generated by the laser chip into a probe beam and a feedback beam, wherein the probe beam is used for target detection; a feedback link for receiving the feedback beam and determining a corresponding feedback electrical signal based on the feedback beam; and a control module for receiving the feedback electrical signal, determining characteristic parameters of the laser beam signal based on the feedback electrical signal, and adjusting the driving signal based on the characteristic parameters, wherein the characteristic parameters include at least one of the following: signal amplitude, frequency modulation bandwidth, and frequency modulation linearity. This invention solves the technical problem of poor modulation effect of laser signals in related technologies.

The invention provides a self-bias instrument input stage circuit based on a bipolar process, and belongs to the technical field of instrument input circuits, the input end of a bias current compensation circuit is connected with the output end of a mirror image constant current source circuit, and the output end of the bias current compensation circuit is connected with the input stage circuit; the input end of the input stage amplification circuit is connected with an external signal input end and the output end of the bias current compensation circuit, and the input end of the input stage amplification circuit is also connected with a P tube proportional current source and an N tube proportional current source output by the mirror current source circuit. Wherein the current flowing through the acquisition tube N2 and the current flowing through the target tube N1 are both determined by a P-type current source through the improved design, and the VCE voltage of the P2 tube and the VCE voltage of the P10 tube are controlled to be basically consistent, so that the influence caused by the width modulation effect of a base region is reduced, the compensation precision is greatly ensured, the bias current required by the input stage from the outside is reduced, and the temperature drift of the bias current is reduced.

This invention provides a multi-magnetic-circuit single-modulation magnetic ring dual-modulation three-rotor coaxial magnetic gear and an automotive hub motor. The magnetic gear includes an inner rotor, a T-shaped dual-modulation magnetic ring, a middle rotor, and an outer rotor. The inner rotor, T-shaped dual-modulation magnetic ring, and middle rotor are nested sequentially and coaxially, forming a radially modulated coaxial magnetic gear structure. The middle rotor, T-shaped dual-modulation magnetic ring, and outer rotor are also nested sequentially and coaxially, forming an axially modulated coaxial magnetic gear structure. Modulation is used between the inner rotor and the middle rotor, and between the middle rotor and the outer rotor. Both modulations share a single T-shaped dual-modulation magnetic ring, achieving a single-modulation magnetic ring dual-modulation effect. This invention can reduce the size of the magnetic gear, improve its torque transmission capacity, suppress magnetic saturation, enhance the magnetic field modulation effect, and increase the torque density of the magnetic gear.

The application discloses a radio frequency signal reading and feedback device applied to electro-optical modulation, comprising: a signal reading unit, which is coupled with an electro-optical modulator and is used for extracting a sampling signal proportional to a radio frequency voltage on a load end; the coupling strength is configured so that the power extracted by the signal reading unit from the electro-optical modulator is less than a preset percentage of the working power of the electro-optical modulator; a feedback control unit, which is connected with the output end of the signal reading unit at the input end and is used for connecting the control end or the output end of a radio frequency signal source, the feedback control unit adjusts the radio frequency driving signal output by the radio frequency signal source to the input end of the electro-optical modulator according to the sampling signal, so that the radio frequency voltage on the load end tends to a target value. The radio frequency signal reading structure is additionally arranged on the electro-optical modulator, the radio frequency signal applied to the electro-optical modulator can be directly read, and the precise regulation and control of the electro-optical modulation effect can be realized without increasing additional photoelectric detectors, detection light paths and other complex schemes.

The invention discloses a chopping amplification circuit and electronic equipment, and belongs to the technical field of electronic circuits. The chopping amplification circuit comprises a transformer switch amplification module, a differential amplification filtering module and a demodulation module, firstly, an input signal is subjected to first-stage amplification through the transformer switch amplification module, and meanwhile, the input signal is modulated to a high-frequency band far away from low-frequency noise; then, the signal enters a differential amplification filtering module, second-stage amplification is carried out, low-frequency noise is removed, and an inherent high-frequency noise signal subjected to differential amplification and a useful high-frequency signal are output together; and finally, based on the modulation effect of the first-stage amplification, the demodulation module demodulates the useful high-frequency signal and the inherent high-frequency noise signal back to a low-frequency band corresponding to the input signal, and the demodulated signal is fed back and superposed on the input signal to form a closed-loop feedback circuit. Therefore, noise interference caused by differential amplification is reduced, low-frequency noise at the input end of the chopping amplification circuit is reduced, and the measurement precision of the chopping amplification circuit is improved.

The invention relates to an infrared modulator based on a graphical two-dimensional material metasurface. The infrared modulator comprises a substrate silicon dioxide (SiO2), a polymer supporting material (the refractive index ranges from 1.6 to 1.8), a metal layer such as gold (Au) or silver (Ag) and an upper-layer two-dimensional material such as graphene and molybdenum disulfide (MoS2). According to the two-dimensional material metasurface based on patterning, the transmissivity of incident light with different wavelengths can be regulated and controlled through the surface plasmon polarization effect, a near-infrared to mid-infrared modulator sensitive to different polarized light is obtained through patterning, meanwhile, a polymer is printed through the 3D printing technology, and the technology becomes simple. The method can realize all-optical calculation, and is applied to image processing, convolutional neural network realization, edge detection and other scenes. The device has the advantages of being simple in structure, convenient to integrate, high in calculation speed, capable of working at the room temperature and the like, patterns can be simply and accurately adjusted on the micrometer scale, and therefore transmission frequency spectrums with different modulation effects are obtained. Wavebands involved in the invention include near-infrared and intermediate-infrared.

This invention relates to the field of optical communication device testing technology, and discloses a testing system and method for the optical performance of a wavelength division multiplexer (WDM), including an optical signal injection monitoring module, a physical field loading isolation module, and a receiving demodulation processing module. The physical field loading isolation module arranges a main test channel, a trans-cabin reference channel, and an equivalent dummy sample channel in parallel, synchronously acquiring optical flow parameters and background transmission variation data to offset common-mode components of external link loss. The measurement signal is decoupled using orthogonal frequency division jitter and a dual-matrix regularization de-embedding model to suppress crosstalk in the spectral response between channels; complex phasor compensation is used to offset the parasitic modulation effect of the light source, extracting the device's true net loss and complex transmission slope; the distance measure between the optical feature vector and the template domain is calculated, and an exponential contraction factor is introduced by combining the environmental state vector to generate a dynamic safe operating envelope model. This invention achieves the separation of environmental disturbances and intrinsic device degradation, establishing a real-time failure assessment boundary.

The application provides a spread spectrum circuit, a power supply system, a chip and an electronic device. The closed loop controlled oscillator comprises a closed loop control module and a voltage controlled oscillator for generating a first clock signal; the spread spectrum circuit comprises a spread spectrum module and a frequency divider for generating a second clock signal with a preset frequency according to the first clock signal; the input end of the spread spectrum module is coupled to the output end of the frequency divider, the output end of the spread spectrum module is coupled to the first input end of the closed loop control module, the output end of the closed loop control module is coupled to the input end of the voltage controlled oscillator, the output end of the voltage controlled oscillator is coupled to the second input end of the closed loop control module and the input end of the frequency divider; the spread spectrum module generates a triangular wave signal according to the second clock signal, and the closed loop control module generates a control signal for driving the oscillator according to the first clock signal and the triangular wave signal. The application can achieve linear frequency modulation effect without complex digital modules, the spectrum energy is uniform, the chip design can be effectively simplified, and the cost can be significantly reduced.

The invention discloses a permanent magnet reluctance motor rotor with low electromagnetic noise and a motor, and belongs to the technical field of permanent magnet reluctance motors. Wherein rotor slotting forms magnetic barriers, a magnetic pole is formed in an area where each group of magnetic barriers are located, the magnetic barriers are asymmetric about a q axis of a geometric center line of the magnetic pole, and a combination of tail angles of the magnetic barriers on two sides of the magnetic barriers is set according to the following mode: extracting a resonance inherent frequency and a resonance vibration mode order in a whole machine mode according to a motor mode vibration mode; extracting air gap radial and tangential flux densities in the operation process of the motor, and calculating air gap radial and tangential electromagnetic forces acting on stator teeth according to a simplified form of a Maxwell stress tensor equation; performing two-dimensional Fourier decomposition on the electromagnetic force to obtain electromagnetic force harmonic waves under each time frequency and space order; and determining a magnetic barrier tail angle combination by taking the minimum resonance inherent frequency, the resonance mode order and the electromagnetic force harmonic density under the corresponding order of the cogging modulation effect as criteria. The rotor is designed through the combination of the magnetic barrier tail angle calculated by the method disclosed by the invention, and the electromagnetic noise can be effectively reduced.

The present application relates to a kind of wind farm primary frequency modulation parameter frequency control method, device and equipment, the method includes the simulation model of island power grid system black start is built;After simulation model runs, according to n*5% island power grid system load is respectively input simulation model, obtain the n primary frequency modulation parameters that meet constraint condition;N primary frequency modulation parameters are all input into the primary frequency modulation control device of island power grid system, and real-time acquisition load parameter in the black start process of island power grid system;According to the load parameter of real-time acquisition, select corresponding primary frequency modulation parameter to control the operation of island power grid system.The method improves the primary frequency modulation modulation effect of island power grid system wind farm, realizes to adapt to the case that island power grid system is in black start period, enhances the reliability and stability of island power grid system operation with the continuous change of load.