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A comparison of noise reduction currents in 36-24 and 18-12 switched reluctance motors in all operating region is presented. Radial force profile in these two machines are compared. It is seen that the difference in radial force profile causes different optimized current to reduce the noise in switched reluctance motor. Analysis, simulation, and experimental results are presented to verify the proposed...
The baseband and intermediate frequency (IF) frequency modulated continuous wave (FMCW) radar receiver topologies are compared on the bases of receiver nonlinearity, time domain interferometry, receiver noise and demodulator port isolation. It is shown that an IF receiver is capable of suppressing distortions, where the same nonlinearity would result in a baseband (or zero-IF) receiver detecting false...
This paper presents a summary of a vibrational behavior investigation of a 27 slots / 24 poles combination surface mounted synchronous electric motor. To achieve this investigation, first, an electromagnetic analysis is done using a quasi 3D finite element model allowing to consider the rotor skewing and to compute the machine magnetic quantities. Second, a modal analysis is done using a 3D FE structural...
Introducing dummy slots is often applied to reduce cogging torque in permanent magnet synchronous machines. Although this solution always helps for smooth operation, its influence on noise and vibration (NV) performance needs more focused analysis. This paper employs two surface-mounted machines to investigate the effect of dummy slots, one of which is a 10-pole/12-slot machine (M1) with few magnetic-field...
In this paper, rotor slits on the rotor's outer circumference is adopted to reduce certain harmonic components of radial forces and, hence, acoustic noise and vibration in an interior permanent magnet synchronous machine (IPMSM). The 48th order of harmonic component for the radial force is found to be responsible for the noise and vibration problem in the studied motor. For this purpose, the influential...
This paper addresses the issue of mitigating the noise emission of high-speed permanent-magnet (HSPM) machines. HSPM machines are increasingly used in a large field of applications for their power density and compactness. However, increasing the speed tends to intensify the noise emissions where more and more applications require a quiet operation. The focus of this paper is to propose a HSPM structure...
The paper presents a system that allows the passive reduction of noise and vibration of a three-phase induction machine with a stator damper winding connected to capacitors. This is a simple and effective system for reducing the flux density harmonics of a machine. The theoretical study is based on the equivalent circuit of a machine equipped with the damper winding and the modeling is based on the...
A method for separating and accurately estimating ADC noise, aperture jitter, and clock jitter is presented for ADC testing and characterization. This significantly relaxes clock jitter requirements and removes the need for high precision test instruments, but still allows ADC specifications like SNR, SNDR and ENOB to be accurately estimated.
Noise of orthogonal fluxgate in fundamental mode has been strongly reduced in the last years, making it a very competitive vectorial sensor of magnetic field at room temperature. The most important results have been achieved reducing the 1/f noise, which can reach about 1 pT/√Hz at 1 Hz. However, the noise floor is still an issue, which cannot be ignored anymore. The problem of the noise floor in...
This paper investigates various random PWM (RPWM) techniques for conventional two-level inverter-fed traction drives and proposes a discrete RPWM technique for acoustic noise reduction. The proposed RPWM technique randomizes within a set of predefined switching frequencies compared with the continuous nature of randomization in conventional RPWM techniques. The proposed method was compared with conventional...
Electric springs (ES) have been proposed as distributed devices for stabilizing the voltage and frequency of AC power systems. Similarly, its DC counterparts in the form of DC electric springs (DC-ES), which are connected in series with non-critical loads to form a smart load, can be applied for the voltage stabilization of DC grids. In this paper, configuration of series and shunt DC-ES and their...
In this paper, class F power amplifier covering a wide dynamic range with a steady gain for non-constant envelope signal used in CDMA systems is designed and studied. The design principle is attempted to operate at high values of peak to average power ratio likely to be up to PAPR = 10dB in such systems. The design also takes care of improving the adjacent channels interference ratio (ACPR) of such...
This paper proposes a speed sensorless technique for induction motor drives based on the retrieval and tracking of the rotor slot harmonics (RSH). The RSH related to the rotor speed is first extracted from the stator phase current signature by the adoption of two cascaded ADALINEs (ADAptive Linear Element), whose output is the estimated slot harmonic. Then, the frequency of this slot harmonic as well...
This paper focuses on the optimal design of Moving Average Filter (MAF). The necessary and sufficient condition for MAF to filter out a group of harmonics with specified orders simultaneously is deduced based on the presented model. Accordingly, the enhanced MAF (EMAF) algorithm is proposed and used for the fast open-loop phase locking of the distorted grid. Compared with the Cascaded Delayed Signal...
Phase synchronization results in distorted grid contain a certain amount of oscillations, failing to meet the requirement of high-performance grid-connected power converters. Moving Average Filter (MAF) and Delayed Signal Cancellation (DSC), as well as their derivations, i.e. Cascaded MAF (CMAF) and Cascaded DSC (CDSC), are main solutions to this problem. In this paper, the mathematical models of...
In this contribution a novel method is discussed that is of practical use for analyzing the electromagnetic compatibility behavior of electronic systems. The aim is to develop an efficient technique that mimics radiated immunity and emission tests in the presence of multiple non-collocated noise sources in simulation. The proposed method is simple in that it only relies on the simulated (or measured)...
We investigate experimentally the influence of harmonic mode-locking and optical feedback on the timing jitter of a passively mode-locked external-cavity diode laser yielding a jitter reduction of up to a factor of 10 and we compare the results with numerical simulations.
Simultaneous transmit and receive systems (STAR) are proposed to double the spectral efficiency and enhance spectrum utilization in the traditional microwave band. A major problem is high power self-interference (SI) due to the proximity of the transmit and receive antennas. In this paper, we propose to significantly improve system-level performance using a novel high isolation RF front-end based...
This paper deals with an adaptive observer methodology for estimating the frequency of an unknown periodic signal with non-zero fundamental component corrupted by unstructured and bounded uncertainties. The proposed estimator is characterized by Input-to-State Stability (ISS) with respect to the bounds on the higher order harmonics and on the unstructured disturbance. The influence of each tuning...
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