10 results about "Mass imbalance" patented technology

Disclosed in the present invention are a fault diagnosis method and system for blade icing and blade mass imbalance of wind turbines. The method comprises the steps of: acquiring operation data and blade icing information of a plurality of wind turbines; labeling the operation data with an icing state label on the basis of the blade icing information, so as to obtain fault data; extracting fault features in the fault data, and ranking the fault features according to the degree of importance, so as to generate an optimal feature set; on the basis of a criterion of minimizing a squared error, selecting optimal features in the optimal feature set to generate an optimal decision tree; and performing classification on the basis of the optimal decision tree, so as to obtain a diagnosis test result including fault information. The present invention has the advantages of a high level of diagnostic accuracy, etc.

This invention relates to a vibration suppression method based on high-precision closed-loop synchronous rotating coordinate transformation. First, a dynamic model of the deflection of a magnetically levitated rotor affected by mass imbalance is established. Then, a synchronous vibration controller based on a high-precision closed-loop synchronous rotating coordinate transformation method is used to track the synchronous frequency disturbance component, and a high-precision closed-loop synchronous frequency signal detection method is employed to improve the detection accuracy of the synchronous frequency vibration signal. Finally, the synchronous frequency vibration signal is eliminated by inverting and compensating the original system, thereby eliminating the synchronous frequency disturbance current and the synchronous frequency vibration torque. This method overcomes the problem of low detection accuracy of synchronous frequency signals in traditional synchronous rotating coordinate transformation methods, effectively improving the suppression effect of synchronous frequency disturbance current, and providing a new control method for unbalanced rotor vibration control. This invention belongs to the field of magnetically levitated rotor control and can be used for unbalanced vibration control of two-degree-of-freedom deflection of magnetically levitated rotors.

The application discloses a radial magnetic bearing displacement vibration suppression method based on a phase shift reduced-order generalized integrator, and comprises the following steps: firstly, a magnetic bearing system model containing rotor mass imbalance is established; then, a synchronous displacement vibration suppression algorithm based on a phase shift reduced-order generalized integrator is designed, the orthogonal relationship of X / Y radial displacement error signals of the magnetic bearing is utilized, and the simultaneous extraction and compensation of double-channel synchronous components are realized; finally, the system stability is analyzed, and the phase shift angle parameters are designed in sections; the phase shift angle is introduced to adjust the phase without changing the amplitude characteristics at the synchronous frequency, so that the system stability is expanded. The application adopts the reduced-order generalized integrator structure, has less state quantity and lower calculation amount, and is suitable for high-speed real-time implementation of DSP / FPGA; the phase shift angle is introduced for phase advance adjustment, so that the stable working range of the algorithm can be effectively expanded; the orthogonal characteristics of the displacement signals are utilized to realize the unified implementation of X / Y double-channel synchronous compensation, and the structure is more simple.

The application discloses an air compressor rotor testing method and testing device, relates to the technical field of air compressor rotor testing, and realizes accurate positioning of the position of rotor mass imbalance by collecting vibration signal data of the rotor at multiple rotating speeds, analyzing by using a fast Fourier transform algorithm, extracting frequency and phase distribution, and performing weighted analysis on the phase distribution to extract initial position coordinates of uneven mass distribution. The least square method is used to fit the offset to obtain mass deviation coordinates, generate an initial counterweight adjustment scheme, combine the gradient descent algorithm to optimize the initial counterweight parameters, obtain an optimized counterweight adjustment scheme, use the particle swarm optimization algorithm to re-iterate the counterweight parameters of the optimized counterweight adjustment scheme, obtain a target counterweight scheme, and ensure that the vibration signal of the rotor meets the vibration balance standard. The application improves the dynamic balance testing efficiency and precision of the air compressor rotor and ensures the stability of the operation of the rotating mechanical equipment.

This invention discloses a method for predicting the multi-physics coupled vibration response of a pump set based on the superposition of frequency domain excitation spectra. The method includes: performing closed-loop flow field calculations of the pump set to extract the time-domain fluid excitation force on the surface of the pump set's flow-through components; performing numerical simulation calculations of the motor's electromagnetic field to extract the time-domain electromagnetic excitation force; establishing a calculation model of the pump's rotor system, applying the rotor system's mass imbalance, time-domain fluid excitation force, and time-domain electromagnetic excitation force, performing transient dynamic calculations of the rotor system, and extracting the time-domain mechanical excitation force; performing modal calculations of the entire pump set to obtain a numerical simulation calculation model of the entire pump set; converting the time-domain fluid excitation force, time-domain electromagnetic excitation force, and time-domain mechanical excitation force into frequency domain excitation spectra using FFT, applying them to the coupling surfaces of the pump body, and performing harmonic response analysis of the pump set under multi-source excitation in the frequency domain to obtain the coupled vibration response results of the pump set. This invention enables rapid and accurate prediction of the multi-physics coupled vibration response of a pump set.

This invention discloses an online diagnosis and location method for generator rotor faults, belonging to the field of generator fault diagnosis technology. The method includes the following steps: S1, arranging a magnetic field sensor array to synchronously acquire the time-domain signal of the air gap magnetic field during operation; S2, performing spectrum analysis to extract the amplitude of the harmonic components at twice the electrical frequency; S3, online diagnosis of either a loose pole bolt fault or a mass imbalance fault; S4, when an online diagnosis of a loose pole bolt fault is made, a shutdown and turning operation is performed. By monitoring the signal strength of the magnetic field sensor located directly below the rotor and finding the point of maximum signal strength, the mechanical angle position of the loose pole is determined. This invention, based on a magnetic field sensor array arranged along the stator circumference and axis, extracts the spatial distribution characteristics of the harmonic amplitude at twice the electrical frequency and compares it with a threshold, enabling accurate online differentiation between loose pole bolt faults and mass imbalance faults, greatly improving the accuracy of online diagnosis.

The application discloses a magnetic bearing same-frequency vibration force suppression method based on a complex LMS algorithm, comprising the following steps: firstly, a dynamic model of a magnetic suspension bearing-rotor system containing rotor mass imbalance is constructed; a radial displacement sensor is used to obtain a first signal; a first complex LMS algorithm and a second complex LMS algorithm with steady-state error compensation are constructed; the first signal is input into the first complex LMS algorithm; a steady-state output is obtained by superimposing an original channel and a compensation channel; weight values are updated based on the calculation error of the steady-state output and the first signal; actual current is obtained; expected current is calculated based on the steady-state output; and a difference between the expected current and the actual current is input into the second complex LMS algorithm to obtain a compensation output. The application can avoid residual current stiffness force caused by inconsistent rotor radial displacement amplitudes, and can compensate displacement stiffness force while suppressing same-frequency current, so that complete suppression of same-frequency vibration force is realized.

The application discloses a kind of propeller automatic balancing device and method of pneumatic and mass imbalance coupling, two the bearing seat is installed on base by hexagon bolt;Motor support is installed on the side of base, and with the mounting hole on base is aligned, and motor support is fixed with hexagon bolt;Stepless speed regulation motor is installed on motor support, two vibration measuring shaft sleeve is connected to the two predetermined measuring point positions of rotating shaft by stainless steel expansion sleeve, bearing is installed on bearing seat, and rotating shaft is installed and fixed by bearing.The shaft end of stepless speed regulation motor is connected with one end of rotating shaft by high-precision plum blossom coupling, and the other end of rotating shaft is installed propeller.The application realizes stepless regulation to wind speed in 0-7000rpm by speed regulating button, while ensuring the precision of blade angle adjustment.

The invention relates to a method for recognizing a rotor imbalance condition of a rotor of a wind power installation, comprising: detecting vibration signals as signal change curves over time in a detection time period, wherein at least longitudinal vibration signals are detected, which reproduce vibrations of the tower in longitudinal direction, i.e. along the rotor axis, and / or transversal vibration signals are detected, which reproduce vibrations of the tower in transversal direction, i.e. transversal to the rotor axis. The method further comprises determining a 1P component from the detected vibration signals, wherein a 1P longitudinal vibration component is determined from the longitudinal vibration signals and / or a 1P transversal vibration component is determined from the transversal vibration signals, respectively, the 1P component being determined such that it contains information about the magnitude and the phase, respectively, and the phase relates to the rotational position of the rotor, respectively. The method further comprises determining an imbalance condition from the 1P component, the imbalance condition comprising a mass imbalance and a blade angle imbalance, and determining the imbalance condition according to at least one imbalance model.

The invention discloses a wind turbine generator impeller mass unbalance detection method, system and device. The method comprises the steps that a variable-pitch motor driving torque value, an impeller azimuth angle, an impeller rotating speed and a variable-pitch angular speed in the running state of a generator are collected in real time; performing data screening according to set screening conditions; aiming at the effective analysis data, calculating to obtain a direct-axis component and a quadrature-axis component of the torque of the variable-pitch motor under the rotating coordinate system; performing spectral analysis, and calculating to obtain a feature vector amplitude and a feature vector phase angle; comparing the amplitude of the feature vector with a diagnosis threshold value, judging whether the impeller has mass unbalance or not, and grading the unbalance degree; and performing mapping positioning in a rotating coordinate system according to the feature vector phase angle so as to preliminarily determine the specific blade causing the impeller imbalance. The variable pitch motor torque is used as a direct monitoring signal, the signal-to-noise ratio is high, and the diagnosis result is more reliable; extra hardware is not needed, and large-scale application is facilitated.