Robust control methodology for the design of supplementary damping controllers for FACTS devices

Abstract

In this paper, a new procedure to design Supplementary Damping Controllers (SDCs) for Flexible Alternating Current Transmission System (FACTS) devices is proposed. The control design problem is formulated as a search for a feasible controller subject to restrictions in the form of Linear Matrix Inequalities (LMIs). The main objective, from the application viewpoint, is the improvement of the damping ratios associated to inter-area oscillation modes. Unlike other types of formulations existing in the literature, this new formulation is capable of explicitly modeling the constraints on the controller bandwidth, which are crucial to avoid undesired amplification of high frequency noise signals coming into the controller input. To illustrate the efficiency of the proposed procedure, the design of an SDC for a Thyristor Controlled Series Capacitor (TCSC) placed in the New England/New York benchmark test system is carried out. The results show the designed controllers are able to provide adequate damping for the oscillations modes of interest for several different operating conditions.<br>Este artigo propõe um novo procedimento para projeto de controladores suplementares de amortecimento (ou SDCs, do inglês Supplementary Damping Controllers) para dispositivos FACTS. O problema de projeto do controlador é formulado como uma busca por um controlador que satisfaça um conjunto de restrições na forma de desigualdades matriciais lineares (ou LMIs, do inglês Linear Matrix Inequalities). Sob o ponto de vista de aplicação, o objetivo principal de controle é aumentar as taxas de amortecimento das oscilações inter-área. Ao contrário de outras formulações propostas na literatura, esta nova formulação é capaz de modelar, explicitamente, as restrições da banda passante do controlador, evitando assim que ruídos em alta frequencia sejam amplificados a partir do sinal de entrada do controlador. Para ilustrar a eficiência do procedimento proposto foi realizado um projeto de controlador suplementar para dispositivos TCSC instalados no sistema New England/New York. Os resultados mostram que os controladores projetados são capazes de fornecer amortecimento adequado para os modos de oscilação de interesse em diversas condições de operação

A new approach for modeling and control of nonlinear systems via norm-bounded linear differential inclusions

“…It is important to emphasize that given the non-convex nature of the undepinning BMI, we cannot guarantee that the LMI problem that is created by setting the matrix Cc obtained from the solution of the state feedback problem will always have a solution. Recent papers, however have shown that this heuristics for calculation of matrix C c provides satisfactory results for the overall design procedure, as seen, for example, in (Ramos et al, 2004;Ramos et al, 2005;Kuiava et al, 2009).…”

Optimal Location of Ipfc in Nigeria 330 KV Integrated Power Network Using Ga Technique

“…Its arrangement can either be combination of shunt and series controllers with effective coordinated control or unified power flow series and shunt controllers [16]. Series and Shunt part inject current and voltage respectively into the transmission network and can exchange power between these two controllers through the power link [29,30] used UPFC to simultaneously regulate power flow through transmission lines (overload and loop flow minimization) and also minimizes power losses without generators rescheduling. The UPFC consist of a STATCOM and a DVR (Direct Voltage Regulator), both sharing a common capacitor on their DC side and a unified control system.…”

“…These controllers are able to provide adequate damping for the oscillation modes of interest for several different operating conditions, in order to improve network stability [30]. Though installing FACTS controllers for the purpose of only stability improvement is not an economical practice (Table 4).…”

Impact of power factor regulation on small‐signal stability of power distribution systems with distributed synchronous generators

“…For example, as shown in Reference [9], given that it is a common practice to set the power injected from the distributed generators to a constant value (regardless of the demanded load), it is reasonable to expect that the dynamics of the generators (and also the damping of electromechanical oscillations) will not be so significantly affected by changes in the operating conditions (which is evidently not true in generation/transmission systems, see for example the tests performed in Reference [28]). …”