Aiming at the problem that change of motor parameters in actual operation will significantly reduce control accuracy motor, this paper proposes a sensorless method permanent magnet synchronous based on an adaptive back-EMF observer. Firstly, vector algorithm, mathematical model coordinate axis transformation is established, online identification flux linkage, and back EMF observer constructed. ...

For sensorless control of surface-mounted permanent magnet synchronous machines (SPMSMs), the major issue is in zero- and low-speed ranges. Since back-electromotive force (EMF) proportional to speed, back-EMF based methods fail at zero low speed. A solution considering starting process speed presented. simplified fundamental model-based method proposed. Based on model, measured stator currents ...

BACKGROUND Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy, the prevalence of which is declining globally. This study was carried out to determine if there were changing patterns in its local prevalence in South-West Nigeria. METHODS We reviewed the medical records of all patients admitted to or attending the cardiology clinic or medical outpatient/specialty clinics in the Depar...

To improve the sensorless control performance of electrical drive systems, a nonsingular terminal sliding mode observer (NTSMO) and adaptive are proposed to solve chattering phase delay problems. Firstly, by defining new surface, based on fast reaching law is designed estimate back electromotive force (EMF). The enhances robustness system eliminates singularity attenuates chattering. Next, obta...

Plant genetic variation and soil microorganisms are individually known to influence plant responses to climate change, but the interactive effects of these two factors are largely unknown. Using long-term observational studies in the field and common garden and greenhouse experiments of a foundation tree species (Pinus edulis) and its mutualistic ectomycorrhizal fungal (EMF) associates, we show...

Field oriented control (FOC) of Permanent Magnet Synchronous Motors (PMSM) is utilized in many industrial applications due to its high performance. Semiconductor manufacturers provide specialized solutions and tools for this technique. However, such are protected with closed source codes. This reduces the flexibility performance systems. paper presents conducted studies controller embedded soft...

The article presents a study of the origin extra harmonics in frequency spectrum thermocouple output signal when being heated by sinusoidal waveform current. It is natural to have first harmonic, which arises according Ohm’s law, as product current and total resistance junction conductors, well Peltier, Thomson effects, presence second caused heating conductors. fact that third higher arise con...

This paper proposes a sliding-mode position estimation method for high-speed surface-mounted permanent magnet synchronous machines with LCL filter. The implementation of the filter aims at smoothing motor current and reducing iron loss caused by harmonic currents. Firstly, discrete-time model LCL-filtered drive system is developed. Based on developed model, observer proposed more robustness aga...

the main purpose of this article is to study common-third triad pairs in the chamber music of alfred schnittke. this harmonic device consists of major and minor triads which are a semitone apart and have the same chordal third; c major and c# minor, which will be labeled c.t. e (common-third e), d major and eb minor labeled as c.t. f#, etc. after a short introduction on the history of shared el...