Design of Robust Decentralized Control for UPFC Controller Based on Structured Singular Value

Abstract

New approach based on structured singular value (µ-synthesis) was proposed for the robust decentralized unified power flow controller (UPFC) design. To achieve decentralization, using the Schauder fixed point theorem the synthesis and analysis of multi-input multi-output (MIMO) control system translated into a set of equivalent multi-input single-output (MISO) control system. Power systems similar to other industrial plants contain different kinds of uncertainties which should be considered in controller design procedure. For this reason, the idea of µ-synthesis technique being used for designing of UPFC controllers. The proposed µ-based controller had a decentralized scheme and advantage of a decentralized controller design reduction in the controller complexity and suitability for practical implementation. The effectiveness of the proposed control strategy evaluated under operating conditions on damping of low frequency oscillations in comparison with the classical controller to demonstrate its robust performance through nonlinear time simulation and some performance indices

Dynamic Modeling and Damping Function of GUPFC in Multi-Machine Power System

“…Power system variables such as rotor angle, rotor speed, frequency and electric power can be used to produce a feedback control signal [2][3][4][5][6][7][8][9]. Previous simulation result in [2,[5][6][7][8][9] indicate that by using speed deviation signal, we have the significant result in damping oscillation. In this research, to improve the system stability, the control both of machines (PSS) and GUPFC (POD) are designed using speed deviation signal Δω to produce supplementary signals as control signal.…”

“…On the basis of the linearised model, the lead-lag compensation method is applied for the design of PSS and GUPFC damping controller. Genetic Algorithm method is proposed in this study to determine the PSS and POD controller parameter, as have been used in [6] where this technique was applied in others FACTS devices.…”

“…The secondary function of GUPFC in power system could be stability improvement and oscillation damping [4]. Several studies at limited number have been carried out and reported in some literature using UPFC [5][6][7][8][9][10][11] and/or GUPFC model for transient studies [7]. FACTS devices, the GUPFCs especially, due to their rapid response, recently might be able to play a significant role in transient and oscillatory stability improvement.…”

“…Lead-lag compensator method has been used and considerable result have published in [2,5], PI controller was very popular in damping oscillation [6][7][8]. Recently, heuristic method for optimizing a performance index has been investigated in some references [6,9]. These previous studies show that the elaboration of FACTS controller is always interested in investigation of the power system stability.…”

“…Many FACTS devices model have been established and used to power system dynamic and transient stability studies. Most of these models are dealing with SVC, TCSC, STATCOM, SSSC, IPFC and UPFC [1][2][3][4][5][6][9][10][11] in both single and multi machine system. GUPFC model especially in multi machine power system is more complicated and is difficult to meet the paper showing detail process modeling.…”