A unified framework for nonlinear dynamic simulation and modal analysis for control of large-scale power systems

Abstract

This paper presents a framework which allows an easy parallel use of both nonlinear and linear ap-proaches to analyze and damp power oscillations in inter-connected power systems. For this, the Small-Signal Sta-bility tool SMAS3 was interconnected to the dynamic simulation tool EUROSTAG so that one can use in SMAS3 the linearized model of the grid and machines along with their regulations computed by EUROSTAG. Any control solutions synthesized in SMAS3 can be pulled-up into the nonlinear model of EUROSTAG to validate their effi-ciency in a nonlinear dynamic simulation. The final solu-tion can thus be obtained after a sufficient number of iterations of complementary linear/nonlinear analysis and synthesis and this assess the oscillation damping and make sure that the solution proposed by synthesis methods based on the linearized model is still satisfactory in the actual nonlinear context. This framework is used to do the ei-genvalue analysis of a large-scale representation of the European power system and to design in a coordinated manner controllers to damp the power oscillations. Start-ing from this grid, a benchmark to test the performance of the modal analysis algorithms in case of very large scale grids is proposed.