Robust control of static Var compensator-based power oscillation dampers using polynomial control in power systems

Abstract

A static Var compensator (SVC) installed in a power transmission network can be effectively exploited to enhance the damping of low frequency electromechanical oscillations. The application of robust control theory offers more reliable and robust damping controller to achieve desired damping level considering variations in the operating conditions of power system. This paper presents a new approach to design a robust proportional-integral (PI) controller for stabilizing power system oscillations. The variability in operating conditions is captured using an interval polynomial and then, Kharitonov’s theorem is used to design the desired damping controller. The proposed method is based on plotting the stability boundary locus in the ( kp-ki) plane and then computing the stabilizing values of the parameters of a PI controller. Besides stabilization, computation of stabilizing PI controllers that achieve user specified gain margin (Gm), phase margin (Pm) and bandwidth is studied simultaneously. This novel method enables designers to make the convenient trade-off between stability and performance by choosing the proper margins and bandwidth specifications. In addition, the most appropriate stabilizing input signal is selected using Hankel singular value (HSV) and right half plane-zeros (RHP-zeros) for the SVC-based supplementary damping controller. The effectiveness and robustness of the proposed controller are demonstrated using eigenvalue analysis and time-domain simulation for a 16 machine 68-bus test system. The simulations and analysis are implemented in matrix laboratory environment and power system analysis toolbox.

Dual-loop generalized predictive control method for two-phase three-wire railway active power quality controller

“…In recent years, despite the fact that different methods presented to eliminate these problems, none has fully addressed them. Various types of balanced structured ERN transformers (Huang et al, 2006; Mazin and Xu, 2009), flexible alternating current transmission system-based static equipment such as Static VAR Compensator (SVC), thyristor-switched capacitor (TSC) and thyristor-controlled reactor (TCR) (Baseri et al, 2011; Hasanvand and Zamani, 2018; Jianzong et al, 2009), Static Synchronous Compensator (STATCOM) (Sadeghi and Fazel, 2010), passive and active filters (Dash and Ray, 2009; Kwon et al, 2014), hybrid active filters (Tan et al, 2004a) are among the most important solutions. However, due to the weaknesses of primary controllers in confronting all power quality (PQ) issues, the need for a comprehensive compensator was always a concern of experts.…”

An intelligent cascaded fuzzy‐lead‐lag‐based damping control scheme incorporating variable frequency transformer and superconducting magnetic energy storage in multimachine power system

“…12 To reduce oscillations and improve the damping of power systems, various FACTS devices, including the unified power flow controller (UPFC), thyristor controlled series capacitor (TCSC), static synchronous series compensator (SSSC), static var compensator (SVC), and thyristor controlled phase shifter (TCPS), have been proposed. [13][14][15][16] The basic analysis of the incorporation of SVC to improve power system stability is described in Hasanvand and Zamani, 17 and the analysis of the application of SVC to increase LFO damping is also included. It has been demonstrated that the SVC improves the system's ability to damp both local and interarea oscillation modes.…”