The fixed-frequency signal is employed in conventional high-frequency (HF) injection-based sensorless control schemes for interior permanent magnet synchronous motor (IPMSM) drives, which causes significant electromagnetic and acoustic noises. In order to diminish the additional noises, a novel pseudorandom HF (PRHF) injection method investigated this paper. Comparative analysis of power spectra density induced currents carried out among three different schemes: HF, full-period-switch (FPS)...

High frequency (HF) signal injection is an effective sensorless control scheme for interior permanent-magnet synchronous motor (IPMSM) drives to achieve low and zero speed operation. However, the audible noise produced by injected HF often very shrill harsh hear, which restricts actual application. In order reduce noise, a novel pseudo-random square-wave voltage proposed in this paper. The voltages with two different frequencies are randomly into estimated rotor reference frame cycle cycle,...

This paper introduces a novel interior permanent magnet synchronous machine (IPMSM) using parallel configuration of hybrid rare-earth and ferrite magnets (HPMs) V-shape arrangement spokes. Aiming at the same torque with lower volume PMs (REPMs) than double IPMSM for EV application, proposed HPM V-spoke is designed optimized by genetic algorithm. In addition, electromagnetic performance, mechanical strength high speed demagnetization withstand capability are analyzed finite element analyses...

The spherical joint with clearances can be modeled as an axi-symmetric quasi-static contact of a sphere in cavity. Hertz theory based on the assumption nonconformal is often used to represent normal force-displacement relationship for clearances. This limits application theory, especially case occurring large deformation area. Steuermann effective solve conformal problem some cases, but it strictly dependent selecting index n polynomial, which profiles. In this paper, approximate model...

The ironless brushless DC (BLDC) motors are widely used for flywheel due to their light mass, high efficiency, and inertia-to-mass ratio. In this paper, a 2-D analytical solution predicting the magnetic field distribution in an BLDC motor is presented compared with finite-element method (FEM). results of proposed FEM good agreement. It also found that intensity direction change largely coil region, which makes electromotive force (EMF) strands one package different from another. Hence, three...

This article investigates the virtual third harmonic back electromotive force (EMF)-based sensorless drive method for high-speed brushless dc (BLDC) motors. Conventional zero-crossing point (ZCP) detection methods of EMF require hardware low-pass filters and voltage comparators, causing serious phase lag. To avoid undesired lag hardware, proposed employs algorithmic oversampling technique to reconstruct envelope EMF. Besides, number sampling points is dynamically adjusted according...

Abstract As a next‐generation probiotic, Clostridium tyrobutyricum , which is considered obligate anaerobe, has been extensively promising candidate for future use to promote health benefits. The industrial applications were limited by its weak tolerance oxygen stress during fermentation. Here, we enhanced the oxidative of C. L319 deleting peroxide response regulator gene perR using an endogenous CRISPR‐Cas system. mutant strain exhibited greatly improved growth when exposed oxygen, also...

In the high-speed brushless dc drives, long commutation freewheeling duration will increase difficulty of sensorless operation that is based on back electromotive force (EMF) zero-crossing detection. extreme cases when angle exceeds 30°, zero crossing EMF be undetectable, resulting in failure drives. As a result, safety area (SOA) limited by issue. this article, it found pulsewidth modulation (PWM) patterns have big influence angle. Hence, first place, through analytical methods, mechanism...

This article investigates the influence of two nonideal factors on zero-crossing-point-detection-based sensorless control high-speed brushless dc (BLDC) motor, i.e., asymmetric machine parameters and resistance tolerance back electromotive force (EMF) measurement circuit. Influenced by parameter asymmetry, EMF envelopes will shift horizontally from its ideal position. Furthermore, acquisition accuracy is limited Inaccurate result in vertical deviation envelopes. These decrease commutation...

For high-speed brushless DC (BLDC) drives, the switching-to-fundamental frequency ratio is usually insufficient. As a result, commutation errors caused by PWM switching delay are significant, which means power switches will take action at inaccurate instants. This cause low-frequency current oscillations and produce additional losses. In addition, conventional method accumulative in sensorless operation further lead to instability issues region. order suppress these influences, novel...

Probiotics contribute a lot to human health and the occurrence of diseases. Correspondingly, probiotics' safety evaluation probiotic properties have received increasing attention in food industry disease treatment. Clostridium tyrobutyricum L319 is short-chain fatty acid (SCFA)-producing strain isolated from Grana Padano cheese with blowing defect. Our previous study has shown its at genomic level. This focused more on vitro. According results, this no potential virulence factors or...

High-speed brushless dc (BLDC) drives usually operate with low carrier-fundamental frequency ratio, which causes abundant sideband harmonic current components. Some harmonics will be induced in low-frequency range, leading to oscillations and torque ripples. To minimize these undesired harmonics, a novel pulsewidth modulation commutation pattern, i.e., carrier-synchronized (CSC), is proposed this article. For comparison, two conventional patterns, including regular-sampled (RSC),...

Liquid metals, which possess both good electrical conductivity and liquid-like processability, have drawn much attention recently. They are also capable of acting as synthesis templates to guide the deposition other functional materials. Herein, through an in-situ galvanic replacement reaction assisted by ultrasonication, core-shell EGaIn/Ag particles composed EGaIn cores vertically aligned Ag nanoflakes shells were prepared; they further sulfurized yield ternary EGaIn/Ag/Ag2 S composite...

This paper deals with the effects of permanent magnets (PMs) shapes and segmentation types on trapezoidal degrees back electromagnetic force (EMF) torque characteristics rotor losses. The back-EMF waveforms different PMs are calculated through transient finite element method (FEM). It is found that inward eccentricity curvature have no influence shape waveforms. asymmetrical middle sub-PMs applied low magnetic energy product sintered ferrite magnet can obtain better Then, losses PMs'...

To measure current stiffness and displacement of permanent magnet biased radial magnetic bearing, a new measurement method is proposed for magnetically suspended flywheel (MSFW). The detailed in this paper. At first, the suspension force characteristics bearing are studied using circuit finite element (FEM). Second, proposed. It has two procedures, one determination center when gravity rotor +x(+y) direction −x(−y) direction, respectively, then can be obtained, other calculation according to...

This paper investigates the virtual third harmonic back EMF based sensorless drive method for high speed brushless DC (BLDC) motors. Compared to conventional methods, no hardware low-pass-filters (LPFs) or comparators are used, and undesired phase lag is avoided. In addition, influence of asymmetric resistance inductance parameters on commutation analyzed in depth. With parameters, zero crossing points (ZCPs) will deviate from their ideal positions. Consequently, events, which searched ZCPs,...

Maneuvering target tracking is one of the key technologies in space system. The strong unscented Kalman filter presented for data processing which uses a fading factor state estimation. Using current statistical model, UKF tested with real obtained mission measured by ship. Simulation results show good performance proposed method.