A New Approach to Reduce the Nonlinear Characteristics of a Stressed Power System by Using the Normal Form Technique in the Control Design of the Excitation System

Abstract

A new approach to reduce the non-linear characteristics of a stressed power system by using the normal form technique in the control design of the excitation system A new approach to reduce the non-linear characteristics of a stressed power system by using the normal form technique in the control design of the excitation system," in Industry Applications Society Annual Meeting, 2015 IEEE, 2015 A new approach to reduce the non-linear characteristics of a stressed power system by using the normal form technique in the control design of the excitation system AbstractIn this paper, a new approach is presented to reduce the nonlinear characteristics of a stressed power system by reducing its second-order modal interaction through retuning some parameters of the generator excitation system. In order to determine the second-order modal interaction of the system, a new index on nonlinearity is developed using normal form theory. Using the proposed index of nonlinearity, a sensitivity function is formed to indicate the most effective excitation system parameters in the nonlinear behavior of the system. These dominant parameters are tuned to reduce the second-order modal interaction of the system and to reduce the index on nonlinearity. The efficiency of the proposed method is validated using a four-machine two-area test system. Simulation results show that a proper tuning of the excitation controller can reduce the second-order modal interaction of the system and can even improve the transient stability margin of the network. This conference paper is available at Research Online: http://ro.uow.edu.au/eispapers/5608 Abstract--In this paper, a new approach is presented to reduce the nonlinear characteristics of a stressed power system by reducing its second-order modal interaction through retuning some parameters of the generator excitation system. In order to determine the second-order modal interaction of the system, a new index on nonlinearity is developed using normal form theory. Using the proposed index of nonlinearity, a sensitivity function is formed to indicate the most effective excitation system parameters in the nonlinear behavior of the system. These dominant parameters are tuned to reduce the second-order modal interaction of the system and to reduce the index on nonlinearity. The efficiency of the proposed method is validated using a four-machine two-area test system. Simulation results show that a proper tuning of the excitation controller can reduce the second-order modal interaction of the system and can even improve the transient stability margin of the network.Index Terms-index of nonlinearity; modal interaction; nonlinear systems; normal form; transient stability.

An Accurate Third-Order Normal Form Approximation for Power System Nonlinear Analysis

“…Reference [29] proposes an extension of the method to deal with resonant cases. It has become a mature computational tool and other applications have been developed [30], [31], or are still emerging [32].…”

Evaluation of effectiveness of second-order modal interaction in design procedure of synchronous machines controllers

“…A new nonlinearity index (NI) is defined based on the second‐order participation factor. Different from some past developments including Lomei et al, which optimizes NI by readjusting the exciter parameters, both PSS and exciter parameters are tuned offering better results. Besides, by utilizing the nonlinear participation analysis, generators with the highest contribution on lightly damped or unstable inter‐area mode are marked and their controllers are tuned while the rest remain unaffected.…”

“…The significance of adding second‐order terms in linear analysis, such as eigenvectors and participation factors, is investigated in Sanchez‐Gasca et al and Rodriguez‐Villalon and Medina . The results in Lomei et al shows that reducing the second‐order modal interaction through retuning excitation system improves the transient stability boundaries. Based on the second‐order term of NF theory, a nonlinear sensitivity index is proposed which picks the best generating units for allocating PSS .…”

“…Besides, by utilizing the nonlinear participation analysis, generators with the highest contribution on lightly damped or unstable inter‐area mode are marked and their controllers are tuned while the rest remain unaffected. This leaves computation saving with respect to the algorithm in Lomei et al The optimization of SI + NI objective functions by readjusting PSS and exciters parameters are conducted using intelligent algorithms. While many algorithms could be used, modified genetic algorithm showed adequate for providing promising results.…”

Power System Nonlinear Modal Analysis Using Computationally Reduced Normal Form Method

“…This aroused interest in the use of NF for control designs. In [9], an approach for control design of the excitation system based on NF was proposed. Various research works show that the nonlinear participation factors analysis possible with NF, could provide more reliable information than the linear one (see for example, [6,10,11]).…”