Improving robustness against grid stiffness, with internal control of an AC voltage-controlled VSC

Voltage Source Converter-based transmission grids might be the future of power system with the increasing share of interfaced electricity generation. These systems should be able to support the utility grid autonomously. The present paper focuses on the VSC output filter design and internal control of filter states. Nested AC current and voltage loops are the state of the art for power converters, controlled as voltage sources, in Microgrid or UPS applications. These internal controls are candidates for future industrial implementation at high power level. However, in a VSC based transmission system, those controls will face various topologies while requiring robustness against transient events (load changes, line tripping, etc.). The following development aims at providing keys for designing a versatile internal control suitable for VSC-based transmission system.