10 results about "Harmonic cancellation" patented technology

The invention discloses an axial flux permanent magnet synchronous reluctance motor rotor based on modular harmonic counteracting, the rotor is designed in a three-in-one mode of structure modularization, magnetic barrier gradient and phase computable dislocation, a rotor assembly is formed by splicing N fan-shaped rotor modules along the circumference, and the adjacent modules are provided with optimal dislocation angles calculated according to the harmonic counteracting principle. The sum of target harmonic magnetic field vectors generated by each module is zero; a U-shaped magnetic barrier array of which geometric parameters are monotonically changed in a gradient manner is arranged in the fan-shaped rotor module, and a permanent magnet group is embedded in the fan-shaped rotor module; main electromagnetic harmonic waves are offset from the source, magnetism gathering and resistance increasing functions are decoupled, the mechanical robustness and the electromagnetic performance of the motor are improved, meanwhile, overall machining is converted into standardized module assembling, the manufacturing cost and the maintenance difficulty are reduced, different motor pole numbers can be flexibly adapted, and the service life of the motor is prolonged. The method is suitable for high-end application scenes such as new energy automobiles, industrial driving and aerospace.

This invention discloses a general construction method for a bearingless magnetic gear double-sided motor with global fundamental harmonic cancellation. The method consists of three levels: preliminary optimization, constraint 1 for the cancellation of armature magnetic field harmonics and permanent magnet harmonics before modulation, and constraint 2 for the cancellation of armature magnetic field harmonics and permanent magnet harmonics after modulation. Preliminary optimization can only reduce the pulsation generated by the fundamental wave of the levitation magnetic field and the stationary wave of the permanent magnet. Based on this, constraint 1 is proposed to reduce the levitation force pulsation generated by the armature magnetic field harmonics and permanent magnet harmonics before modulation, and constraint 2 is proposed to reduce the levitation force pulsation generated by the armature magnetic field harmonics and permanent magnet harmonics after modulation. Through the principle of global fundamental harmonic cancellation, this invention effectively reduces the levitation force pulsation of the bearingless magnetic gear double-sided motor, overcoming the shortcomings of traditional and existing levitation motor construction methods.

The application belongs to the technical field of electric machines, and discloses a magnetic suspension fan variable frequency driving device and a harmonic suppression method; the method comprises the following steps: judging a transient operation process and activating a phase compensation mechanism by monitoring the state of the electric machine in real time, extracting harmonic components in real time and updating a weight vector to obtain harmonic currents of different orders; meanwhile, a phase compensation amount is dynamically obtained based on a pre-built control loop phase lag atlas, an anti-phase harmonic voltage is calculated in combination with the harmonic currents and the compensation phase, and the variable frequency device is injected through a space vector pulse width modulation method to realize accurate harmonic cancellation; torque safety monitoring is also independently operated in parallel in the whole process, the electromagnetic torque and its change rate are detected in real time to perform safety logic determination, and a protection action is triggered when the limit is exceeded; the application can realize accurate cancellation of anti-phase harmonics and actual interference harmonics in the transient process, significantly reduce the instantaneous impact of the electromagnetic torque, and effectively improve the operation stability and reliability of the magnetic suspension fan variable frequency driving system under transient working conditions.

A radio frequency circuit includes a transmit power amplifier, a differential transmit signal path having first and second paths, and first and second baluns. The first balun can be configured to convert a single ended transmit signal into a differential transmit signal, and the second balun can be configured to convert the differential transmit signal back to a single ended transmit signal. The circuit can also include a pair of transmit filters between the first and second baluns and including a first transmit filter connected in the first path and a second transmit filter connected in the second path. The second balun cancels harmonic noise generated by the pair of transmit filters.

This invention belongs to the field of sensors and signal processing, specifically relating to a wavelet kernel-scale sensitivity-guided denoising method for abrasive particle induced voltage signals. The method includes: acquiring abrasive particle induced voltage signals and performing harmonic cancellation to obtain a preprocessed signal; constructing a wavelet kernel function and calculating a kernel-scale guided spectrum using it and the preprocessed signal; constructing a sparse joint denoising model based on the kernel-scale guided spectrum; processing the sparse joint denoising model to obtain a convex optimization objective function; solving the convex optimization objective function using an adaptive step-size gradient descent method and an adaptive iterative shrinking threshold method to obtain a weight vector characterizing the distribution of abrasive particle characteristic signals; binarizing the weight vector characterizing the distribution of abrasive particle characteristic signals to obtain a feature indicator vector; performing a Hadamard product between the feature indicator vector and the preprocessed signal, followed by low-pass filtering to obtain a denoised signal. This invention can adaptively and non-destructively enhance and denoise abrasive particle characteristic signals under strong interference environments.

The invention discloses a real-time harmonic suppression and compensation method for a DAC output end, and the method comprises the steps: collecting harmonic characteristic parameters of an output signal through a high-precision DAC calibration test platform, and carrying out the cooperative processing of a cascade notch dynamic harmonic cancellation model, a frequency band weight adaptive distribution model and a nonlinear even harmonic enhancement algorithm, harmonic feature extraction, model parameter configuration, weight distribution, even harmonic enhancement, dynamic offset and real-time feedback correction are sequentially completed. According to the method, model parameters are dynamically adjusted to adapt to a complex harmonic scene, the processing precision is improved by means of multi-model linkage and real-time feedback, the method has the advantages of being high in adaptability, accurate in processing and good in stability, DAC output signal distortion can be greatly reduced, the signal purity and reliability are improved, and the method is suitable for large-scale popularization and application. The method is suitable for communication, industrial control, test measurement and other environments with strict signal precision requirements.

Apparatus and methods may include receiving a square wave having a frequency at an input of a harmonic cancellation (HC) sine wave generator; receiving a clock signal having a clock frequency at a clock input of the HC sine wave generator; generating, using one or more delay components of the HC sine wave generator, one or more delayed square waves based on the received square waves and the clock signal; and amplitude scaling the square wave and the one or more delayed square waves using a plurality of taps of the HC sine wave generator to produce a plurality of amplitude scaled square waves. The method may include adding the plurality of amplitude scaled square waves using summing circuitry of the HC sine wave generator to generate a sine wave at an output of the HC sine wave generator, the sine wave having a tone at the frequency of the square waves and a suppressed signal strength at a selected harmonic of the frequency.

The present disclosure relates to a resonator with intrinsic second harmonic cancellation. The resonator can include a first electrode, a second electrode, and a piezoelectric material between the first electrode and the second electrode, where the piezoelectric material is formed by fabricating the piezoelectric material with a compression axis vector (C-axis vector) oriented along a first direction and applying an electric field across the piezoelectric material to modify the direction of the C-axis vector to be oriented along a second direction. The second direction can be antiparallel to the first direction.

This invention provides a harmonic suppression method for a T-type three-level inverter using active reconfiguration of switch combinations, relating to the field of power electronics technology. Addressing the shortcomings of existing methods that rely on precise modeling and have poor dynamic adaptability, this method acquires the three-phase output voltage in real time and extracts the harmonic deviation vector. Based on its direction angle, a lookup table is used to select the corresponding switch combination as the modulation mode. The drive pulses of the selected switches are actively shielded to change the available set of the basic voltage vector. A linear equation system for the modulation time correction is established, and the SVPWM modulation time is reconstructed. A compensation voltage opposite to the original harmonic deviation is synthesized, and this process is iterated in a closed loop until the harmonic deviation is below a threshold. This method does not change the main circuit, does not rely on precise mathematical models, and does not affect the fundamental frequency control. It achieves directional harmonic cancellation through dynamic reconfiguration of switch combinations, effectively reducing the total harmonic distortion rate and adapting to high power quality scenarios such as motor drives and new energy grid integration.

Devices and methods may include receiving a square wave having a frequency at an input of a harmonic-cancellation (HC) sine-wave generator; receiving a clock signal having a clock frequency at a clock input of the HC sine-wave generator; generating one or more delayed square waves based on the received square wave and the clock signal using one or more delay components of the HC sine-wave generator; and amplitude-scaling the square wave and the one or more delayed square waves using a plurality of taps of the HC sine-wave generator to produce a plurality of amplitude-scaled square waves. The method may include adding the plurality of amplitude-scaled square waves using summing circuitry of the HC sine-wave generator to produce a sine wave having tone at the frequency with suppressed signal strength at selected harmonics of the frequency of the square wave at an output terminal of the HC sine-wave generator.