Time delay margins computation for stability of load frequency control in hybrid renewable energy power generation/storage system

Creative Commons License

Erol H., Ayasun S.

El-Cezeri Fen ve Mühendislik Dergisi, cilt.9, sa.2, ss.382-393, 2021 (Scopus, TRDizin)

Özet

In load frequency control (LFC) systems, it is important to transmit control signals from remote terminal units (RTU) to the control center and from the control center to the plant side. Because of this data exchanges, time delays in signal transmission become unavoidable. These delays reduce the dynamic performance of the LFC system and may even destabilize the system. This paper is dedicated to the delaydependent stability analysis of the LFC scheme containing a renewable energy power generation subsystem. The system under study includes photovoltaic system (PV), ultra-capacitor (UC) bank for energy storage, wind turbine generator (WTG), diesel generator (DG) and fuel cell (FC) system. Using a frequency-domain exact method, stability delay margins of the system are determined theoretically for different values of inertia, damping factor as well as controller gains. The relation between the controller gains and the delay margin is investigated. The upper bound of the delay time for which the LFC system is marginally stable is known as stability delay margin. Theoretical delay margins are verified by time-domain simulation studies. Delay margin computations are realized by using an analytical method approach. Proportional-integral (PI) controller is used for controlling proposed power generation storage system. PI Controller parameters are chosen in a wide range to observe the effect of the parameter space on delay margin variation. Simulation studies verify the effectiveness of the proposed method