Yük frekans kontrol sistemlerinde gürbüz kararlılık zaman gecikmesi paylarının belirlenmesi

Öz

Bu çalışma, zaman gecikmesi içeren Yük Frekans Kontrol (YFK) sistemlerinde parametrik belirsizliklerin olması durumunda sistemin gürbüz kararlılık gecikme payı değerlerini hesaplamayı amaçlamaktadır. YFK sistemlerinde frekans kararlılığının sürdürülmesi bakımından çeşitli elektrik verilerinin ölçülerek kontrol merkezine iletilmesi ve kontrol merkezinden frekans kontrol servisine katılım sağlayan santrallere kontrol sinyallerinin iletilmesi gerekmektedir. Bu süreçte, haberleşme ağlarında veri iletimi nedeniyle, zaman gecikmeleri kaçınılmaz hale gelmektedir ve sistemin dinamik performansı ve kararlılığı olumsuz etkilenmektedir. Ayrıca, YFK sisteminin modellenmesinden kaynaklı ve güç sisteminde oluşabilecek belirsizlikler nedeniyle sistem parametrelerinin belirsizlikleri dikkate alınarak haberleşme ağı tabanlı gözlemlenebilecek gecikme değerleri üzerinde böylesi belirsizliklerin etkisi incelenmelidir. Bu amaçla, YFK sisteminde üstel terimin yok edilmesi yöntemi ile Kharitonov Teoremi birlikte kullanılarak sistemin gürbüz kararlılığını sağlayabilen gürbüz zaman gecikme payı değerlerinin teorik olarak hesaplanması sağlanmıştır. Aynı zamanda Matlab/Simulink programı ve QPmR (Quasi Poliynomial Mapping Root Finder) algoritması kullanılarak elde edilen teorik sonuçların doğruluğu kanıtlanmıştır.

Anahtar Kelimeler

• Yük frekans kontrol sistemi
• Haberleşme zaman gecikmesi
• Kharitonov teoremi
• Üstel terimlerin yok edilmesi yöntemi

Determination of the robust stability delay margins for the load frequency control systems

Öz

This study computes the robust stability delay margins of the time delayed load frequency control (LFC) system towards parametric uncertainties. The LFC systems are extensively equipped with communication networks to maintain the system frequency stability and to transmit/receive the measurement and control signals between the control central and generation units. However, network induced time delays due to the extensive utilization of communication networks are inevitable in LFC systems. Such delays could negatively affect the LFC system stability and could degrade the dynamical performance of system. Moreover, the parametric uncertainties are significant challenges for robust stability of the LFC system. Therefore, the effect of parametric uncertainties on the communication delay values could be investigated. For this purpose, this study determines the robust stability delay margin of LFC system by cooperating the direct method and Kharitonov theorem. The accuracy of theoretical computations is verified by the time domain simulations and QPmR algorithm.

Anahtar Kelimeler

• Load frequency control
• Communication time delay
• Kharitonov theorem
• Direct method.

Kaynakça

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