This thesis provides an investigation of the dynamics and control of turbogenerators from a multivariable control viewpoint. The multivariate control framework chosen -Individual Channel Analysis and Design- is particularly appropriate since it encapsulates the dynamical characteristics of the uncontrolled system with a view to exposing the potential and limitations for subsequent closed-loop control. The main contribution of the thesis is a complete new insight into why excitation/governor control with Power System Stabilisers (PSS) has been so successful for the control of turbogenerators connected to an infinite bus provided by the small-signal multivariable analysis framework, Individual Channel Analysis and Design. The multivariable analysis justifies treating the turbogenerator system as a pseudo- Single-Input Single-Output, (SISO) system where the governor loop is first closed and the exciter loop is treated as a SISO system for the prime purpose of rejecting voltage disturbances. The function of the PSS is identified as that of overcoming an awkward switch-back frequency-domain characteristic of the excitation channel so as to permit high-performance excitation channel bandwidths up to 10 rad/sec that otherwise could not be obtained. Thus, in addition to the control requirements of set point regulation of the terminal voltage and shaft speed, the PSS provides for a second control requirement of strong voltage disturbance rejection over the important frequency range of 0 to 10 rad/sec. The PSS control option is also assessed against other control options. Several other results concerning stability robustness to system uncertainties in different system configurations follow from the analysis in a transparent and immediate way.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:360182 |
| Date | January 1996 |
| Creators | Mohammed, Zakaria Fadlalmoula |
| Publisher | University of Glasgow |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://theses.gla.ac.uk/1727/ |
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