Electromechanical wave propagation in a non-uniform continuum power system

Continuum modeling technique is a completely novel scheme for studying the electromechanical dynamic characteristics of large-scale power systems, using which the continuum model with non-uniform parameters is obtained while modeling a real power system. For a one-dimensional continuum power system with non-uniform parameters, while both the per-unit length susceptance and the rotor's inertia change in the form of power functions of spatial coordinate, utilizing the variables substitution, the Lommel equations about electromechanical wave propagation described by the rotor relative angular speed and incremental power are presented, and the exact steady-state analytical solutions expressed by Bessel functions are also solved. Next, the characteristic impedance and the wave speed expressions of electromechanical wave propagation are derived from the steady-state solutions. Finally, an example is analyzed about the electromechanical wave propagation in a continuum power system with non-uniform parameters. The results show that the parameters' non-uniformity of the continuum power system leads to the waveform distortion of electromechanical wave, and is reflected at any location. Furthermore, both propagation velocity and characteristic impedance are functions of the spatial coordinates. © 2010 Chinese Society for Electrical Engineering.