3 results about "Harmonic cancellation" patented technology

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.

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.

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.