Synchronous Generators Modeling and Control Using the Framework of Individual Channel Analysis and Design: Part 1

Abstract

In this paper a comprehensive dynamical assessment of a high order synchronous generator plant is carried out using the Individual Channel Analysis and Design (ICAD) framework -a multivariable control engineering tool that allows robustness and system performance evaluations. The great benefits of ICAD are elucidated and contrasted to those provided by the long-time honored block diagram representations. Several models used for the small signal stability analysis of synchronous generators are evaluated under the framework of ICAD. The study, which builds on pioneering work, reveals the great advantages of carrying out control system analysis and design with higher order generator models. Moreover, careful analysis of the ICAD's Multivariable Structure Function (MSF) helps to explain, formally, why some operating conditions of the control system are more critical than others. Furthermore, correct interpretations of MSFs are amenable to robust and stable control system designs. Two kinds of studies are considered in the paper; one assesses operation under various power factor conditions and the other under a varying tie-line reactance. The control system design and stability and structural robustness assessment of the system are presented in the second part of this paper. Moreover, results obtained under the ICAD framework are compared with those arising from conventional controllers.

Analysis of the damping characteristics of two power electronics-based devices using ‘individual channel analysis and design’

“…Such phenomenon is caused by a resonance (lightly damped left hand plane pole -LHPP-pair) followed by an inverted resonance (lightly damped left hand plane zero -LHPZ-pair) present around 7 rad/s, which reduces the SG performance due to bandwidth limitation [22] . In the case of an SVC-upgraded system with damping capabilities, an auxiliary control loop is included [4,5] .…”

“…on a 100 MVA base). The SG model corresponds to the fifth-order dynamic model presented in [22] . A TCSC with parameters of the Kayenta installation [24] is used.…”

“…The construction of G SG (s ) is provided in detail in [22] . The individual elements of G SG (s ) can be found in the supplementary file accompanying this paper.…”

“…Moreover, coupling within the SG is low under a lagging power factor operation and relatively short tie-lines; however, it increases with electrical distance. It has also been shown that the larger the amount of reactive power flow in the tie-line reactance the higher the coupling between channels [22] . These results are important since they may dictate a control design strategy shared by the two cases here studied.…”

Individual Channel Analysis of the Thyristor-Controlled Series Compensator Performance

“…Nevertheless, further research is required as the existing analysis tools, although applicable to large-scale systems (Kundur, et al, 1990), may lack physical transparency. As previously discussed by Leithead and O'Reilly (1992) and Ugalde, et al (2007), Individual Channel Analysis and Design (ICAD) provides an alternative and very insightful control-oriented framework with which to carry out small-signal stability assessments.…”