scholarly journals New Fast Arctangent Approximation Algorithm for Generic Real-Time Embedded Applications

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5148
Author(s):  
Mohieddine Benammar ◽  
Abdulrahman Alassi ◽  
Adel Gastli ◽  
Lazhar Ben-Brahim ◽  
Farid Touati
Keyword(s):  
Approximation Algorithm ◽  
Power Systems ◽  
Rational Approximation ◽  
Zero Point ◽  
Approximation Formula ◽  
Practical Implementation ◽  
Approximation Techniques ◽  
Accuracy Requirement ◽  
Practical Evaluation ◽  
Main Approximation

Fast and accurate arctangent approximations are used in several contemporary applications, including embedded systems, signal processing, radar, and power systems. Three main approximation techniques are well-established in the literature, varying in their accuracy and resource utilization levels. Those are the iterative coordinate rotational digital computer (CORDIC), the lookup tables (LUTs)-based, and the rational formulae techniques. This paper presents a novel technique that combines the advantages of both rational formulae and LUT approximation methods. The new algorithm exploits the pseudo-linear region around the tangent function zero point to estimate a reduced input arctangent through a modified rational approximation before referring this estimate to its original value using miniature LUTs. A new 2nd order rational approximation formula is introduced for the first time in this work and benchmarked against existing alternatives as it improves the new algorithm performance. The eZDSP-F28335 platform has been used for practical implementation and results validation of the proposed technique. The contributions of this work are summarized as follows: (1) introducing a new approximation algorithm with high precision and application-based flexibility; (2) introducing a new rational approximation formula that outperforms literature alternatives with the algorithm at higher accuracy requirement; and (3) presenting a practical evaluation index for rational approximations in the literature.

scholarly journals Simulation of Incidental Distributed Generation Curtailment to Maximize the Integration of Renewable Energy Generation in Power Systems

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4173 ◽  
Author(s):  
Ingo Liere-Netheler ◽  
Frank Schuldt ◽  
Karsten von Maydell ◽  
Carsten Agert
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Distributed Generation ◽  
System Integration ◽  
Best Practice ◽  
Flow Analysis ◽  
Real Data ◽  
Load Flow ◽  
Practical Implementation

Power system security is increasingly endangered due to novel power flow situations caused by the growing integration of distributed generation. Consequently, grid operators are forced to request the curtailment of distributed generators to ensure the compliance with operational limits more often. This research proposes a framework to simulate the incidental amount of renewable energy curtailment based on load flow analysis of the network. Real data from a 110 kV distribution network located in Germany are used to validate the proposed framework by implementing best practice curtailment approaches. Furthermore, novel operational concepts are investigated to improve the practical implementation of distributed generation curtailment. Specifically, smaller curtailment level increments, coordinated selection methods, and an extension of the n-1 security criterion are analyzed. Moreover, combinations of these concepts are considered to depict interdependencies between several operational aspects. The results quantify the potential of the proposed concepts to improve established grid operation practices by minimizing distributed generation curtailment and, thus, maximizing power system integration of renewable energies. In particular, the extension of the n-1 criterion offers significant potential to reduce curtailment by up to 94.8% through a more efficient utilization of grid capacities.

scholarly journals Study on the Method for Analyzing Electric Network Resonance Stability

Energies ◽  
2018 ◽  
Vol 11 (3) ◽  
pp. 646 ◽  
Author(s):  
◽  
◽  
◽  
Keyword(s):  
Power Systems ◽  
Systematic Approach ◽  
Zero Point ◽  
Resonance Region ◽  
Oscillatory Behavior ◽  
Linear Network ◽  
Electric Network ◽  
Resonance Modes ◽  
Point Solution ◽  
Power System Oscillations

With the increasing utilization of power electronic equipment in power systems, there has been an increase in the occurrence of oscillatory behavior from unknown sources in recent years. This paper puts forward the concept of electric network resonance stability (ENRS) analysis and tries to classify the above-mentioned oscillations into the category of ENRS. With this method, many complex power system oscillations can be analyzed with the linear network theory, which is mathematically mature. The objective of this paper is to establish a systematic approach to analyze ENRS. By introducing the s-domain nodal admittance matrix (NAM) of the electric network, this paper transforms the judgment of ENRS into the zero-point solution of the determinant of the s-domain NAM. First, the zero-points of the determinant of the s-domain NAM are proved to correspond to the eigenvalues of the system. Then, a systematic approach is proposed to analyze ENRS, which includes the identification of the dominant resonance region and the determination of the key components related to resonance modes. The effectiveness of the proposed approach for analyzing ENRS is illustrated through case studies.

scholarly journals Demand management by active consumers in intelligent electric power systems

2020 ◽  
Vol 157 ◽  
pp. 05006
Author(s):  
Evgeny Tretyakov
Keyword(s):  
Power Systems ◽  
Electric Power ◽  
Technological Process ◽  
Demand Management ◽  
Electric Power Systems ◽  
Digital Data ◽  
Practical Implementation ◽  
Processing Technologies ◽  
Digital Data Processing ◽  
Network Schedule

The approaches to demand management by active consumers through forming a given schedule of power consumption in the required period of time based on the solution of the optimization problem in the form of maximizing the power of connected controlled electric receivers of various types are presented. The model of demand management by active consumers is justified, taking into account the following factors: load sensitivity for connecting a transformer substation to a change in consumer load; load priority; consistent load reduction levels with flexible performance and power control; permissible set of electric receivers in accordance with the technological process, network schedule, other logical conditions corresponding to adjacency lists. An algorithm has been developed for limiting power on the part of active consumers based on the widespread use of digital data processing technologies, modern technical means of measurement, control and switching of end consumers in real time. The presented research results indicate the validity of the demand management method by active consumers in the normal mode of intelligent electric power systems and the possibility of its practical implementation in an industrial enterprise with reference to the technological process.

scholarly journals Inverse-Problem-Based Accuracy Control for Arbitrary-Resolution Fairing of Quasiuniform Cubic B-Spline Curves

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Xiaogang Ji ◽  
Jie Xue ◽  
Yan Yang ◽  
Xueming He
Keyword(s):  
Inverse Problem ◽  
Approximation Algorithm ◽  
Linear Hypothesis ◽  
Accuracy Control ◽  
B Spline ◽  
Accuracy Requirement ◽  
Dyadic Wavelet ◽  
Spline Curves ◽  
Minimum Number ◽  
Fairing Process

In the process of curves and surfaces fairing with multiresolution analysis, fairing accuracy will be determined by final fairing scale. On the basis of Dyadic wavelet fairing algorithm (DWFA), arbitrary resolution wavelet fairing algorithm (ARWFA), and corresponding software, accuracy control of multiresolution fairing was studied for the uncertainty of fairing scale. Firstly, using the idea of inverse problem for reference, linear hypothesis was adopted to predict the corresponding wavelet scale for any given fairing error. Although linear hypothesis has error, it can be eliminated by multiple iterations. So faired curves can be determined by a minimum number of control vertexes and have the best faring effect under the requirement of accuracy. Secondly, in consideration of efficiency loss caused by iterative algorithm, inverse calculation of fairing scale was presented based on the least squares fitting. With the increase of order of curves, inverse calculation accuracy becomes higher and higher. Verification results show that inverse calculation scale can meet the accuracy requirement when fitting curve is sextic. In the whole fairing process, because there is no approximation algorithm such as interpolation and approximation, faired curves can be reconstructed again exactly. This algorithm meets the idea and essence of wavelet analysis well.

scholarly journals 3-adic complexity of ternary generalized cyclotomic sequences with period

2021 ◽  
Vol 2052 (1) ◽  
pp. 012008
Author(s):  
V A Edemskiy ◽  
S A Koltsova
Keyword(s):  
Approximation Algorithm ◽  
Rational Approximation ◽  
Generalized Cyclotomic Classes ◽  
Definition Of ◽  
Cyclotomic Sequences

Abstract In this paper, we study the ternary generalized cyclotomic sequences with a period equal to a power of an odd prime. Ding-Helleseth’s generalized cyclotomic classes of order three are used for the definition of these sequences. We derive the symmetric 3-adic complexity of above mention sequences and obtain the estimate of symmetric 3-adic complexity of sequences. It is shown that 3-adic complexity of these sequences is large enough to resist the attack of the rational approximation algorithm for feedback with carry shift registers.

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