Excitation control for multimachine power systems

The control of power systems on the basis of energy analysis offers many advantages. An essential condition to achieve this control is the measurement of the angles of the major generator groups, which are available using satellite Global Positioning Systems.This paper develop two strategies based on energy function higher order derivatives to design nonlinear excitation controllers for multimachine power systems taking into consideration field flux decay effects.The design is based on maximum reduction of energy and can be successfully implemented with as many controllers as major modes, when few controllers are available control on the basis of energy function higher order derivatives produce good results.The first strategy is based on energy function higher order derivatives design where one controller is required to control one mode of oscillation.The second strategy capable of suppressing the oscillation modes with only one controller is based on a linear optimal control design where a linear quadratic regulator (LQR) control component added to energy function higher order derivatives design.