DECENTRALIZED LOAD-FREQUENCY CONTROL USING INTERACTION ESTIMATION AND ACTIVE DISTURBANCE REJECTION

Mojtaba Hassanzadeh | Mohammad Reza Jahed Motlagh | Mohammad Hosein Kazemi

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=31633
Date :  2015/12/01
Publish in :    The Mediterranean Journal of Measurement and Control


Keywords :DECENTRALIZED, LOAD-FREQUENCY, CONTROL, ESTIMATION, ACTIVE, DISTURBANCE, REJECTION

Abstract :

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Decentralized active disturbance rejection control (ADRC) using interaction estimation is proposed in this paper for loadfrequency control (LFC) problem in a multi-area power system. A generalized disturbance is estimated by an extended state observer (ESO), and a state feedback control is used to reject it and track the reference signal. The generalized disturbance includes the interactions between subsystems, that is the main problem with a decentralized ADRC. Unlike the existing literature, in the proposed method, the interactions are not considered as a part of disturbances. They are estimated using an unknown input observer (UIO) and local controllers use the estimations to neutralize the interactions in each area. The ESO is also generalized to estimate higher order disturbances rather than just step load disturbances. The simulation results for a three-area power system demonstrate the effectiveness of the proposed method in comparison with the existing methods, especially when the interactions are increased. It is shown that the interaction estimation improved the controller performance and also the stability margin, while needing a little information about other subsystems, which resulted in better robustness against variations of the system parameters.