ROBUST EXCITATION CONTROLLER-DESIGN FOR SYNCHRONOUS GENERATORS USING OUTPUT-FEEDBACK

In this work an alternate systematic procedure is proposed for the con trol of high-order multiple-input multiple-output (MIMO) linear time-i nvariant open-loop system models. The procedure forms the correspondin g high-order single-input multiple-output (SIMO) open-loop model from which it obtains an adequate reduced-order SIMO open-loop model (all s tates of which are measurable and may be made to coincide with its out put variables). Then an implementable controller based on the reduced- order SIMO model, using the spectral pole-placing algebraic control me thod with complete state-feedback, is derived. The controller of the r educed-order SIMO model is then used for controlling the original high -order MIMO open-loop system model. The proposed control approach was applied to a linearized 9th-order MIMO open-loop synchronous generator system model and yielded an implementable excitation controller, whic h was tested successfully in three more operating points of the over- and under-excitation regions of the generator for proving its desired robustness. The four designed 9th-order MIMO closed-loop systems displ ayed remarkably improved dynamic stability characteristics.