STABILITY ANALYSIS OF AUTOMATIC VOLTAGE REGULATOR SYSTEM WITH FRACTIONAL PI CONTROLLER

Şevgin E., Çelik V.

II. INTERNATIONAL FUTURE ENGINEERING CONFERENCE, Baku, Azerbaycan, 28 - 29 Nisan 2025, ss.288-299, (Tam Metin Bildiri)

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Basıldığı Şehir: Baku
  • Basıldığı Ülke: Azerbaycan
  • Sayfa Sayıları: ss.288-299
  • Van Yüzüncü Yıl Üniversitesi Adresli: Evet

Özet

The need for electrical energy is constantly increasing with the development of modern societies.

Power systems are a critical building block in meeting this need. Uninterrupted and reliable operation

of the system is of great importance in all processes from electricity generation to the end user. This

trust is based on the stability of the system. For this reason, analyses on the stability of power systems

constitute an important part of the studies in the field of energy. In this paper, the stability of the

Automatic Voltage Regulator (AVR) system is analysed by using a fractional PI controller. The

fractional PI controller is preferred because it offers a wider control parameter range than the

conventional PI and provides design flexibility. In this study, using the Stability Boundary Locus

(SBL) method, the regions of the controller gains (Kp, Ki) that determine the stable, unstable and

critically stable states of the system are determined based on the characteristic equation of the system.

The stability boundary curves obtained for different fractional integral degrees (λ = 0.4, 0.5, 0.6) are

shown in the Kp-Ki plane and graphically analysed with which gain pairs the system will operate

stably. The time responses of three different points selected from these regions were tested in

MATLAB/Simulink environment. According to the results of the analyses; parameters within the

stability boundary curves make the system stable, parameters above the boundary make the system

critically stable and parameters outside the boundary make the system unstable. Simulations

confirmed the theoretical stability analyses and showed that fractional PI controllers are effective in

improving the AVR system performance and providing a wider stability domain. The study

demonstrates the applicability of fractional controllers to AVR systems and provides designers with

more flexible and safe control strategies.