System-Level Stability of the CIGRE Low Voltage Benchmark System: Definitions and Extrapolations

With the higher penetration of renewable energy and non-linear loads, modern power systems are prone to disturbances due to low inertia and naturally more vulnerable than synchronous-generator-dominated grids. The unstable modes of these systems may vary from disturbances, relevant topologies and multiple time scales in operation. Accordingly, identification of the unstable modes is of importance to formalize guidelines for stability-oriented design of power-electronic-based power systems (PEPS), and to validate the performance of PEPS. In this paper, the CIGRE Low Voltage (LV) benchmark system, which is an exemplary model for up-to-date topics on microgrids, is studied to explore the unstable modes of a microgrid. The performances of the CIGRE LV benchmark system are explored based on the classification of stability, and the unstable modes are identified according to respective root causes, features and consequences. Simulations and experiments based on the CIGRE LV benchmark system are also demonstrated and conclusions are thereby drawn.