Wyniki wyszukiwania - BazTech

1

Genetic PID and Feedforward controllers for DC-DC chopper converter

Obeidat Mohammad A.

Przegląd Elektrotechniczny

|

2022

|

R. 98, nr 7

30--35

EN

DC voltage choppers such as buck, boost, and buck/boost are widely used in electrical power applications. Since these choppers are connected directly between DC source such as solar photovoltaic PV systems or batteries, a disturbance or dc source fluctuations may occur at the input of chopper circuits. Therefore, the control systems must be designed and developed in order to reduce such an increase or decrease in voltage. In this paper, two control strategies have been studied and analyzed to reduce system disturbance and minimize the error resulted from noise. The first strategy uses both feedback and feedforward controllers, in this strategy the controllers are designed based on linearization system. The second strategy uses genetic algorithm to tune the integrated proportional, integral, and differentiator PID feedback controller parameters directly for the nonlinear system. The results show that, the genetic PID controller has better performance than the Feedforward/Feedback controller. The mathematical model of the chopper-controlled system using both strategies and the simulation results are extracted using Matlab/Simulink 2018.

PL

Przerywacze napięcia stałego, takie jak buck, boost i buck/boost, są szeroko stosowane w zastosowaniach elektroenergetycznych. Ponieważ przerywacze te są połączone bezpośrednio między źródłami prądu stałego, takimi jak fotowoltaiczne systemy fotowoltaiczne lub akumulatory, na wejściu obwodów przerywacza mogą wystąpić zakłócenia lub wahania źródła prądu stałego. Dlatego też układy sterowania muszą być projektowane i rozwijane w celu ograniczenia takiego wzrostu lub spadku napięcia. W niniejszym artykule zbadano i przeanalizowano dwie strategie sterowania w celu zmniejszenia zakłóceń systemu i zminimalizowania błędu wynikającego z hałasu. Pierwsza strategia wykorzystuje zarówno regulatory sprzężenia zwrotnego, jak i sprzężenia do przodu, w tej strategii regulatory są projektowane w oparciu o system linearyzacji. Druga strategia wykorzystuje algorytm genetyczny do dostrojenia parametrów zintegrowanego regulatora proporcjonalnego, całkowego i różniczkowego ze sprzężeniem zwrotnym PID bezpośrednio dla systemu nieliniowego. Wyniki pokazują, że genetyczny regulator PID ma lepszą wydajność niż regulator sprzężenia zwrotnego/zwrotnego. Model matematyczny systemu sterowanego chopperem wykorzystujący obie strategie i wyniki symulacji są wyodrębniane za pomocą Matlab/Simulink 2018.

2

A repeatability study of artificial neural network predictions in flow stress model development for a magnesium alloy

Siewior Hubert, Madej Łukasz

Computer Methods in Materials Science

|

2021

|

Vol. 21, No. 4

209--218

EN

This work is devoted to an evaluation of the capabilities of artificial neural networks (ANN) in terms of developing a flow stress model for magnesium ZE20. The learning procedure is based on experimental flow-stress data following inverse analysis. Two types of artificial neural networks are investigated: a simple feedforward version and a recursive one. Issues related to the quality of input data and the size of the training dataset are presented and discussed. The work confirms the general ability of feedforward neural networks in flow stress data predictions. It also highlights that slightly better quality predictions are obtained using recursive neural networks.

3

Forecasting economic and financial indicators by supply of deep and recovery neural networks

Boyko N., Ivanets A., Bosik M.

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

|

2018

|

Vol. 7, No 2

3--8

EN

This paper studies the potential of the application of the Recurrent Neural Networks, as well as the Deep Neural Networks in the field of the finances and trading. In particular, their use in the stock price predicting software. The concepts of the RNNs and DNNs are provided and explained thoroughly. Both techniques RNNs and DNNs are utilized in the implementation of the stock price predicting software. Two separate versions of the software are created in order to demonstrate the main differences between the algorithms, as well as to determine the best of the two. Each version is thoroughly examined. The comparison of each of the algorithms is performed and highlighted. Examples of the implementations of the software, utilizing each of the algorithms on big volumes of stock data, for stock price prediction are provided. The article summarizes the concept of stock price prediction backed by the popular machine learning algorithms and its application in the nowadays world.

4

A simplified control strategy for single-phase UPS inverters

Monfared M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2014

|

Vol. 62, nr 2

367--373

EN

Though there are many strategies to control single-phase uninterruptible power supply (UPS) inverters, they suffer from some drawbacks, the main being complexity. This paper proposes a simple dual-loop controller for the single-phase UPS inverter with the LC filter. The suggested control scheme uses the capacitor current as the feedback signal in the inner current loop. No fictitious phase generation or reference frame transformations are required, and simple proportional gains are employed as both voltage and current regulators. A feedforward of the derivative of the output voltage is also proposed, which significantly improves the performance of the closed loop control system. Then, based on the model of the inverter with the proposed control strategy, a simple and systematic design procedure is presented. Finally, the theoretical achievements are supported by extensive simulations.

5

Robust fractional adaptive control based on the strictly positive realness condition

Ladaci S., Charef A., Loiseau J. J.

International Journal of Applied Mathematics and Computer Science

|

2009

|

Vol. 19, no 1

69-76

EN

This paper presents a new approach to robust adaptive control, using fractional order systems as parallel feedforward in the adaptation loop. The problem is that adaptive control systems may diverge when confronted with finite sensor and actuator dynamics, or with parasitic disturbances. One of the classical robust adaptive control solutions to these problems makes use of parallel feedforward and simplified adaptive controllers based on the concept of positive realness. The proposed control scheme is based on the Almost Strictly Positive Realness (ASPR) property of the plant. We show that this condition implies also robust stability in the case of fractional order controllers. An application to Model Reference Adaptive Control (MRAC) with a fractional order adaptation rule is provided with an implementable algorithm. A simulation example of a SISO robust adaptive control system illustrates the advantages of the proposed method in the presence of disturbances and noise.

6

Eco-Humanism and Popular System Dynamics as Preconditions for Sustainable Development

Michnowski L.

Problemy Ekorozwoju

|

2008

|

Vol. 3, nr 2

31-50

EN

This article is parallelly published by Luis T. Gutierrez in the Solidarity, Sustainability, and Non-Violence Research Newsletter – (http://pelicanweb.org/solisustv03n11michnowski.html). This article is an overview of a book by the author: "Vision of sustainable development society – future of the world from cyberneticist perspective” (in Polish), published by Polish Academy of Sciences, Committee for Futures Studies "Poland 2000 Plus", Warsaw Poland 2006 (Michnowski, 2006).. This book contains my conclusions from - System of Life reality conceptual model based - systems analysis of global crisis essence and world society sustainable development, especially information, conditions creating. The main thesis of mine is: to avoid global catastrophe, NO LIMITS TO WISDOM BASED GROWTH AND SUSTAINABLE DEVELOPMENT OF THE HUMANKIND.

7

On convergence and stability of adaptive active noise control systems

Pawełczyk M.

Archives of Acoustics

|

2006

|

Vol. 31, No. 4

529-535

EN

The problems of convergence and stability of adaptive active noise control systems with the Filtered-Reference LMS algorithm are discussed. First, the assumptions required to derive convergence conditions are collected and addressed. Then, it is demonstrated that feedback systems are subject to convergence conditions different than those used for feedforward systems. Moreover, the problems of convergence of the adaptation algorithm and stability of the structural feedback loop are coupled. Theoretical considerations are supported by simulations experiments.

8

Sprzężenie wyprzedzające w badaniach nad jakością edukacyjną

Kowalski J.

Problemy Jakości

|

2001

|

nr 10

39-43

PL

W pracy przedstawiono badania nad jakością edukacyjną z wykorzystaniem sprzężenia wyprzedzającego (feedforward). Badanie zamodelowano w postaci mechanizmu predykacji skutku jako przyczyny.

9

Optimal design of model following control with genetic algorithm

Zhang X., Yamane Y.

Control and Cybernetics

|

2001

|

Vol. 30, no 1

71-79

EN

This paper presents a genetic algorithm for the optimal design of model following control in which there are nonlinear disturbance and unceratin parameters, where the output is regulated to follow the output of reference model. The effectiveness of the proposed algorithm is illustrated by numerical examples.