Comparative Analysis of Improved Grid Forming Control Design Methods for Islanded Grid with Static and Rotating Energy Sources

Abstract

Concerns about long-term sustainability and stability have led to an unprecedented shift in electric power systems toward the rapid integration of renewable generation. This integration is achieved via application of power electronic converters, leading to low inertia networks. A system with low inertia is deficient in maintaining system stability. In this context, voltage source converters with grid-forming control are proposed to provide inertia to the network which was previously provided by synchronous machines. However, the majority of grid forming control analysis ignores the DC side dynamics and transmission line parameters. In this paper, three grid forming control techniques with DC side dynamics are explored, and their interaction with the synchronous machine in low inertia test cases are presented. The test results are validated using MATLAB/Simulink simulation of a modified IEEE 9-bus system.