scholarly journals A Test Bed for Evaluating Frequency Estimation Algorithms in Synthetic Inertia Control: User Manual.

2020 ◽  
Author(s):  
Felipe Wilches Bernal ◽  
William Balliet ◽  
Joshua Wold
Keyword(s):  
Frequency Estimation ◽  
Test Bed ◽  
Estimation Algorithms ◽  
Inertia Control

A case for multi-level optimisation in aeronautical design

1999 ◽  
Vol 103 (1028) ◽  
pp. 481-485 ◽  
Author(s):  
G. M. Robinson ◽  
A. J. Keane
Keyword(s):  
Computational Cost ◽  
Design Tool ◽  
Test Bed ◽  
Design Environment ◽  
Aircraft Wing ◽  
Computing Power ◽  
Transport Aircraft ◽  
Estimation Algorithms ◽  
Multi Level ◽  
Optimisation Algorithms

Abstract This paper discusses how the inevitable limitations of computing power available to designers has restricted adoption of optimisation as an essential design tool. It is argued that this situation will continue until optimisation algorithms are developed which utilise the range of available analysis methods in a manner more like human designers. The concept of multi-level algorithms is introduced and a case made for their adoption as the way forward. The issues to be addressed in the development of multi-level algorithms are highlighted. The paper goes on to discuss a system developed at Southampton University to act as a test bed for multi-level algorithms deployed on a realistic design task. The Southampton University multi-level wing design environment integrates drag estimation algorithms ranging from an empirical code to an Euler CFD code, covering a 150,000 fold difference in computational cost. A simple multi-level optimisation of a civil transport aircraft wing is presented.

scholarly journals Frequency Estimation for Grid-Tied Inverters Using Resonant Frequency Estimator

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6513
Author(s):  
Dariusz Zieliński ◽  
Karol Fatyga
Keyword(s):  
Resonant Frequency ◽  
Frequency Estimation ◽  
Short Circuit ◽  
The Novel ◽  
Diesel Generator ◽  
Estimation Algorithms ◽  
New Strategy ◽  
Frequency Changes ◽  
Novel Strategy ◽  
Frequency Estimator

This paper introduces a new strategy of frequency estimation for grid-tied and stand-alone mode AC/DC power converters. Frequency stabilization is required, especially when operating in stand-alone mode with a Droop Control strategy, or in hybrid mode with a Diesel generator. It is also required to reduce or increase power output along with grid frequency changes. The novel strategy utilizes a resonant filter to estimate the frequency of the voltage grid and is referenced as a resonant-frequency-estimator (RFE). A mathematical background is presented for the proposed estimator and its performance is evaluated. It is compared with three common frequency estimation algorithms: SRF-FLL, DDSRF-FLL, and DSOGI-FLL. Results are presented for three cases: frequency swing, harmonics injection, and type B short-circuit. Results are analyzed and the conclusion shows that the proposed novel strategy has comparable parameters to commonly used frequency estimation algorithms while having a loopless structure.

Design of Signal Processing System for Doppler Speed Radar Based on SOPC

2011 ◽  
Vol 464 ◽  
pp. 237-240
Author(s):  
Xiao Fei Wang ◽  
Bo Quan Li ◽  
Hai Bin Pan
Keyword(s):  
Signal Processing ◽  
Frequency Estimation ◽  
Processing System ◽  
Gain Control ◽  
Doppler Signal ◽  
Signal Processing System ◽  
Estimation Algorithms ◽  
Spectral Analysis Method ◽  
Velocity Measuring ◽  
Future Work

Doppler speed radar is a high precision velocity measuring instrument based on Doppler Effect, which has widely applications in measuring moving target’s velocity. In this paper, a novel design of Doppler signal processing system was presented to perform projectile’s speed measurement tasks. The system architecture is based on an Altera Cyclone II chip and designed as a System-on-a-Programmable-Chip (SOPC) with the help of an embedded Nios II software processor. And the SOPC system integrates CPU, memory, I/O interface and some other reconfigured modules required in system. According to the proposed scheme, the peripheral circuits were designed in this system, such as signal condition, A/D conversion and auto gain control (AGC) circuit. We also proposed to use spectral analysis method based on windowed FFT to deal with the measured target’s Doppler signal. Further, the signal source of simulating targets was used to testify the system feasibility. In addition, future work can include the further study on frequency estimation algorithms or comparisons of the proposed architecture with traditional design.

scholarly journals Online Estimation Techniques for Natural and Excitation Frequencies on MDOF Vibrating Mechanical Systems

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 41
Author(s):  
Gerardo Silva-Navarro ◽  
Francisco Beltran-Carbajal ◽  
Luis Gerardo Trujillo-Franco ◽  
Juan Fernando Peza-Solis ◽  
Oscar A. Garcia-Perez
Keyword(s):  
Degrees Of Freedom ◽  
Frequency Estimation ◽  
Mechanical Systems ◽  
Algebraic Approach ◽  
Estimation Algorithms ◽  
Lumped Parameter ◽  
Harmonic Components ◽  
Stiffness And Damping ◽  
Euler Bernoulli Beam ◽  
Vibrating Systems

An online algebraic estimation technique for natural and forcing frequencies for a class of uncertain and lumped-parameter vibrating mechanical systems with n degrees of freedom is described. In general, realistic vibrating systems can be affected by unknown exogenous excitation forces with multiple and independent frequency harmonic components. Hence, natural frequencies as well as excitation force frequencies can be simultaneously computed from an algebraic approach into a small interval of time during online operation of the mechanical system. Measurements of an available output signal, associated with some specific degree of freedom, are only required for frequency estimation in time-domain. Information on mass, stiffness and damping matrices are not necessary for multifrequency estimation algorithms. Some analytical, numerical and experimental results on a cantilever Euler–Bernoulli beam are described to show and validate the acceptable estimation of multiple frequencies in forced multiple degrees of freedom vibrating systems.

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