Power System Coherency and Model Reduction

This chapter mainly focuses on nonlinear model reduction process and presents the power system dynamic model reduction as used in the industry. It also focuses on coherency and generator aggregation and model reduction for discussing the basis for the power system model reduction tools used in the power industry. The chapter shows a comparison of the accuracy of the simulated time responses from the methods. It describes linear model reduction methods and the coherency and aggregation tools available in the power system toolbox. The chapter also discusses the concepts supporting the various aspects of power system model reduction. It provides the analytical justification for slow coherency due to the sparse and weak connection between coherent areas. The chapter also provides methods of aggregating coherent generators including the singular perturbation methods to improve on the reduced models.