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Igor Boiko - One of the best experts on this subject based on the ideXlab platform.

  • loop tuning with specification on gain and Phase margins via modified second order sliding mode control algorithm
    International Journal of Systems Science, 2012
    Co-Authors: Igor Boiko
    Abstract:

    The modified second-order sliding mode algorithm is used for controller tuning. Namely, the modified suboptimal algorithm-based test (modified SOT) and non-parametric tuning rules for proportional-integral-derivative (PID) controllers are presented in this article. In the developed method of test and tuning, the idea of coordinated selection of the test parameters and the controller tuning parameters is introduced. The proposed approach allows for the formulation of simple non-parametric tuning rules for PID controllers that provide desired amplitude or Phase margins exactly. In the modified SOT, the Frequency of the self-excited oscillations can be generated equal to either the Phase Crossover Frequency or the magnitude Crossover Frequency of the open-loop system Frequency response (including a future PID controller) – depending on the tuning method choice. The first option will provide tuning with specification on gain margin, and the second option will ensure tuning with specification on Phase margin. ...

Dahlborg Elin - One of the best experts on this subject based on the ideXlab platform.

  • Frequency control : Pay for performance
    Uppsala universitet Elektricitetslära, 2015
    Co-Authors: Dahlborg Elin
    Abstract:

    The Frequency control in the Nordic grid is to a large extent delivered by hydropower plants. The hydropower plants deliver Frequency control of varying quality, meaning that a remuneration method based on more than just the static gain of the power plant is called for. This thesis has examined how three remuneration methods based on the hydropower plant output and the grid Frequency deviation affects the grid stability. Using Frequency data, the remunerated work along with the bandwidth and Phase-Crossover Frequency was plotted and compared for varying governor settings. The results show that all three remuneration methods examined need constructive technical specifications (for example based on the Frequency response) to not decrease the grid stability. The first remuneration method, where the power plant is remunerated for being on the right side of the power set point value as the grid Frequency deviates, gave incentives for increased bandwidth, but no particular incentives regarding the Phase-Crossover Frequency. The second remuneration method, where the power plant is remunerated for how well it matches the output power from a plant with no dynamics using a proportional controller, gave incentives for moderately high bandwidth and Phase-Crossover Frequency. The third remuneration method, which remunerates how well the plant power output matches the load disturbance that gave rise to the grid Frequency deviation, needs to be investigated further, but the initial analysis show that it did neither give incentives for increased bandwidth nor Phase-Crossover Frequency

V. Veselý - One of the best experts on this subject based on the ideXlab platform.

  • Ultimate Data Based Robust PID Design for Performance
    2016
    Co-Authors: Š. Bucz, A. Kozáková, V. Veselý
    Abstract:

    Abstract: A novel PID tuning method is presented to achieve prescribed performance (in terms of maximum overshoot and settling time) for uncertain systems with unstructured uncertainties. In the first step of the design procedure the plant is identified using a harmonic excitation signal with Frequency n. In the second step, two recently developed PID controller design approaches are applicable: 1. the approach based on guaranteed Phase margin M suitable for systems without integral behaviour and with/without time delay, and for systems with integral behaviour; 2. the approach based on guaranteed gain margin GM, suitable for systems without integral behaviours with unstable zero. Both approaches are based on shifting a selected point of the Frequency response of the unknown system into the gain Crossover Frequency (if using the M approach) or the Phase Crossover Frequency (if using the GM approach). The developed algorithm has been extended to robust PID controller design for plants with unstructured uncertainties

Uğur Demiroğlu - One of the best experts on this subject based on the ideXlab platform.

  • Farklı analitik denetleyici tasarım yöntemlerinin incelenmesi ve uygulamaları / Investigation and applications of various analytical controller design methods
    2019
    Co-Authors: Uğur Demiroğlu
    Abstract:

    Bu tez çalışmasında, birinci ve ikinci dereceden zaman gecikmeli modellerin kararlılık, dayanıklılık ve performansı için oransal integral, oransal türev ve kesir dereceli oransal integral denetleyicilerin analitik tasarım şemaları sunulmuştur. Sunulan yöntem söz konusu sistemler için genelleştirilmiş denklemleri vermektedir. Denetleyici parametrelerinin ayarlanması, ideal bir sistemin karakteristiklerinden esinlenilerek gerçekleştirilmiştir. Tez çalışması boyunca verilen teoremlerle önce birinci ve ikinci dereceden zaman gecikmeli modeller için istenen kazanç kesim frekansı ve faz payını sağlamada kullanılacak denetleyici parametreleri elde edilmiştir. Daha sonra ise önerilen "frekans çerçevesi" yöntemi ile söz konusu sistemlerin aynı anda kazanç kesim frekansı, faz kesim frekansı ve faz payı özelliklerini sağlaması için gereken kesir dereceli oransal integral denetleyici parametreleri elde edilmiştir. Önerilen bu yöntem Bode grafiğindeki faz eğrisini şekillendirmede kullanılabileceği için sistemin hem kararlılığını sağladığı hem de dayanıklılığını artırdığı gözlemlenmiştir. Sunulan tüm teoremler literatürden alınmış modeller üzerinde test edilmiş ve tez çalışmasından elde edilen sonuçların etkinliği gösterilmiştir. ANAHTAR KELİMELER: Analitik, Denetleyici, Tasarım Yöntemleri, Kararlılık, UygulamalarAnalytical design schemes of proportional integral, proportional derivative and fractional order proportional integral controllers for the stability, robustness and performance of first and second order plus time delay models are presented in this thesis. Presented method gives the generalized equations for mentioned systems. Tuning of the controller parameters are inspired from the characteristics of an ideal system. Throughout the theorems given in the thesis, first, controller parameters are obtained to satisfy desired gain Crossover Frequency and Phase margin for first and second order models. Then, with the proposed method "Frequency frame", parameters of the fractional order proportional integral controller are obtained to satisfy gain Crossover Frequency, Phase Crossover Frequency and Phase margin properties simultaneously. Since the proposed method can be used to shape the Phase curve of the Bode plot, it is observed that the method improved both the stability and the robustness of the system. All proposed theorems are tested on existing models from the literature and effectiveness of the results obtained from the thesis are shown. KEYWORDS: Analytical, Controller, Design Methods, Stability, Application

Matušů Radek - One of the best experts on this subject based on the ideXlab platform.

  • Analytical approach on the design of fractional order proportional-integral controller for second order plus time delay models
    'Gazi Universitesi Iktisadi ve Idari Bilimler Fakultesi Dergisi', 2021
    Co-Authors: Şenol Bilal, Demiroǧlu Ugur, Matušů Radek
    Abstract:

    Purpose: This paper presents the design scheme to tune fractional order proportional-integral controller for models described by second order plus time delay transfer functions. Theory and Methods: Main purpose of the design is to tune the gain Crossover Frequency, the Phase Crossover Frequency and the Phase margin simultaneously towards researchers' desire. Tuning these Frequency properties will let us control the output behavior of the system. Main contribution of the method comes from computation of the Frequency specifications simultaneously and the flattening procedure of the Phase curve. In spite of the similar existing studies, the Phase curve is simply flattened by tuning the above mentioned Frequency specifications. For example, we can flatten the Phase curve by extending the distance between Ωgcand Ωpcreducing the PM in Figure A. In this way, the curve can be flattened without mathematical complexity. Results: The proposed method is applied on two different models selected from the literature. By the analytically derived equations, desired Frequency specifications are successfully achieved. With the proper selection of these specifications, the Phase curve is considerably flattened thus, the systems gained improved robustness against variations in the plant or controller gain. Conclusion: Simulation results showed that the proposed method successfully achieved desired design specifications and significantly improved the robustness of the system. © 2022 Gazi Universitesi Muhendislik-Mimarlik. All rights reserved