Reduced-order analysis of small signal stability modelat the change of operating points

In the analysis of power system small signal stability, the state-space equation which is based on the comprehensive consideration of synchronous generator, automatic excitation system, prime mover and its speed control system and power system stabilizer, is often of high dimension. This makes it difficult for researchers to analyze of all state variables in the dynamic process. The modal perturbation theory employed in the present study can not only reduce the order of the original model and the computational efforts but also obtain the dynamic changes of all state variables. Afterwards, the paper established a complete state-space equation of simple power system and the basic form of reduced-order model. A case study of a single machine was then conducted, in which satisfactory reduction effects were achieved when the original model was reduced to 4th, 3rd and 2nd order models.