scholarly journals Evaluation of Moving Average Window Technique as Low-pass Filter in Microprocessor-Based Protecting Relays

2017 ◽  
Vol 7 (6) ◽  
pp. 2177-2183
Author(s):  
N. Khodabakhshi-Javinani ◽  
H. Askarian Abyaneh
Keyword(s):  
Moving Average ◽  
Least Square ◽  
Main Process ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Dc Offset ◽  
Signal Flow Graphs ◽  
Window Technique ◽  
Low Pass ◽  
Flow Graphs

Over the last decades, with the increase in the use of harmonic source devices, the filtering process has received more attention than ever before. Digital relays operate according to accurate thresholds and precise setting values. In signal flow graphs of relays, the low-pass filter plays a crucial role in pre-filtering and purifying waveforms performance estimating techniques to estimate the expected impedances, currents, voltage etc. The main process is conducted in the CPU through methods such as Man and Morrison, Fourier, Walsh-based techniques, least-square methods etc. To purify waveforms polluted with low-order harmonics, it is necessary to design and embed cutting frequency in a narrow band which would be costly. In this article, a technique is presented which is able to eliminate specified harmonics, noise and DC offset, attenuate whole harmonic order and hand low-pass filtered signals to CPU. The proposed method is evaluated by eight case studies and compared with first and second order low-pass filter.

Adaptive Low-Pass Filter Based DC Offset Removal Technique for Three-Phase PLLs

2018 ◽  
Vol 65 (11) ◽  
pp. 9025-9029 ◽  
Author(s):  
Parag Kanjiya ◽  
Vinod Khadkikar ◽  
Mohamed Shawky El Moursi
Keyword(s):  
Pass Filter ◽  
Low Pass Filter ◽  
Dc Offset ◽  
Three Phase ◽  
Low Pass ◽  
Removal Technique

scholarly journals Degradation Trend Estimation and Prognosis of Large Low Speed Slewing Bearing Lifetime

2014 ◽  
Vol 493 ◽  
pp. 343-348 ◽  
Author(s):  
Bu Yung Kosasih ◽  
Wahyu Caesarendra ◽  
Kiet Tieu ◽  
Achmad Widodo ◽  
Craig A.S. Moodie ◽  
...  
Keyword(s):  
Time Domain ◽  
Moving Average ◽  
Low Frequency ◽  
Vibration Signal ◽  
Accurate Information ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Speed ◽  
Slewing Bearing ◽  
Low Pass

In many applications, degradation of bearing conditions is usually monitored by changes in time-domain features. However, in low speed (< 10 rpm) slewing bearing, these changes are not easily detected because of the low energy and low frequency of the vibration. To overcome this problem, a combined low pass filter (LPF) and adaptive line enhancer (ALE) signal pre-conditioning method is used. Time-domain features such as root mean square (RMS), skewness and kurtosis are extracted from the output signal of the combined LPF and ALE method. The extracted features show accurate information about the incipient of fault as compared to extracted features from the original vibration signal. This information then triggers the prognostic algorithm to predict the remaining lifetime of the bearing. The algorithm used to determine the trend of the non-stationary data is auto-regressive integrated moving average (ARIMA).

Trajectory Measurement of Radial Jet Drilling Wells: Improved Tool and Data Processing

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Zhe Huang ◽  
Zhongwei Huang ◽  
Long Wu ◽  
Yinao Su ◽  
Chunyang Hong
Keyword(s):  
Moving Average ◽  
Cost Effective ◽  
Circuit Board ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Failure Risk ◽  
Time Operation ◽  
Low Pass ◽  
Current Design ◽  
Trajectory Measurement

Abstract Drilling by high-pressure liquid jet, radial jet drilling (RJD) is a cost-effective technology to restimulate the production of old wells and the development of unconventional reservoirs. However, due to the unique process of 90 deg turning in the casing, hardly any traditional tool can be applied in the RJD trajectory measurement. Even minitools have been developed in the last few years; the increasing cost and unpredictable failure risk of lateral re-entrance are still non-negligible as the current design, much less than the huge measuring errors. In this paper, a new tool was proposed. Based on a special-shaped circuit board and separation of the supporting section, a fluid passageway was reserved in the measuring section to realize the measurement while or after the jet drilling without extra trips. It reduces the cost and failure risk of lateral re-entrance. Ample space in the supporting section was also provided, which meets the long-time operation requirements and establishes the base for real-time communication and trajectory control. Based on noise analyses, random walk is the main source of system noise in short-time measurements, and the effective measuring frequency is mostly in the range of 0–5 Hz. Therefore, autoregressive moving average (ARMA) models, Kalman filter, and low-pass filter were established for denoising. It allows us to analyze the data feature in more detail and extract the valid measuring data with improved accuracy. Considering performance tests result, the average errors of reckoned parameters were improved to less than 15%.

A THEOREM ON REPEATED FILTERING

2014 ◽  
Vol 23 (10) ◽  
pp. 1450136
Author(s):  
ANTONIJE DJORDJEVIĆ ◽  
DEJAN TOŠIĆ ◽  
MILICA DJURIĆ-JOVIČIĆ
Keyword(s):  
Group Delay ◽  
Moving Average ◽  
Gaussian Filter ◽  
Pass Filter ◽  
Low Pass Filter ◽  
First Order ◽  
Gaussian Filters ◽  
Low Pass ◽  
Butterworth Filters

Repeatedly passing a signal through a low-pass filter may resemble using a Gaussian or hyper-Gaussian filter. Conditions are established for this resemblance. A theorem on approximation of Gaussian and hyper-Gaussian filters by a cascade of simple filters is established and the corresponding phase and group delay characteristics are analyzed. The theorem and the analysis are exemplified by cascading moving-average filters and the first-order Butterworth filters.

DVCC based (2+α) order low pass Bessel filter using optimization techniques

2021 ◽  
Author(s):  
Ashu Soni ◽  
Maneesha Gupta
Keyword(s):  
Transfer Functions ◽  
Search Algorithm ◽  
Optimization Technique ◽  
Optimization Techniques ◽  
Least Square ◽  
Current Conveyors ◽  
Circuit Realization ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

Abstract This paper proposes the design and analysis of (2+α) order low pass Bessel filter using different optimization techniques. The coefficients of the proposed filter are found out by minimizing the error between transfer functions of (2+α) order low pass filter and third-order Bessel approximation using simulated annealing (SA), interior search algorithm (ISA), and nonlinear least square (NLS) optimization techniques. The best optimization technique based on the error in gain, cut off frequency, roll-off, passband, stopband, and phase is chosen for designing the proposed filter. The stability analysis of the proposed filter has also been done in W-plane. The simulated responses of the best optimized proposed filter are obtained using the FOMCON toolbox of MATLAB and SPICE. The circuit realization of 2.5 order low pass Bessel filter is done using two DVCCs (differential voltage current conveyors), one generalized impedance converter (GIC) based inductor, and one fractional capacitor. The proposed filter is implemented for the cut off frequency of 10 kHz using a wideband fractional capacitor. Monte Carlo noise analyses are also performed for the proposed filter. The MATLAB and SPICE results are shown in good agreement.

CONVERGENCE OF A CONVOLUTION-FILTERING-BASED ALGORITHM FOR EMPIRICAL MODE DECOMPOSITION

2009 ◽  
Vol 01 (04) ◽  
pp. 561-571 ◽  
Author(s):  
CHAO HUANG ◽  
LIHUA YANG ◽  
YANG WANG
Keyword(s):  
Empirical Mode Decomposition ◽  
Iterative Algorithm ◽  
Moving Average ◽  
Limit Function ◽  
Continuous Variables ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Mode Decomposition ◽  
Low Pass ◽  
Convolution Filters

Lin et al. propose the iterative Toeplitz filters algorithm as an alternative iterative algorithm for Empirical Mode Decomposition (EMD). In this alternative algorithm, the average of the upper and lower envelopes is replaced by certain "moving average" obtained through a low-pass filter. Performing the traditional sifting algorithm with such moving averages is equivalent to iterating certain convolution filters (finite length Toeplitz filters). This paper studies the convergence of this algorithm for signals of continuous variables, and proves that the limit function of this iterative algorithm is an ideal high-pass filtering process.

Detection Experiment Research of Harmonic Current for Single-Phase Active Power Filter

2014 ◽  
Vol 701-702 ◽  
pp. 297-302
Author(s):  
He Feng Shao ◽  
Hui Min Quan
Keyword(s):  
Single Phase ◽  
Moving Average ◽  
Response Speed ◽  
Superior Performance ◽  
Phase System ◽  
Harmonic Current ◽  
Reactive Component ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

In order to solve the problem of detecting harmonic and reactive currents of single-phase APF, the paper gives a detection method for real time harmonic current and reactive current. In the paper, it makes use of some characteristics of triangle function, and calculates the amplitude of active and reactive component from load current. Then the DC component can be extracted by using a low-pass filter, namely the required active component and reactive component. This paper analyzes the characteristics of two kinds of low pass filter, and selects the superior performance moving average filter for experiment. The paper introduces the design of the software and hardware process. The circuit configuration of the proposed approach used in the single-phase system is simple, its dynamic response speed is fast and its detection precision is high. The result of the experiment shows that the proposed approach is feasible and valid.

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