Relative Gain Array Application for a VSC Grid-Connected Converter

This study investigates the behavior of a voltage source converter in $abc,\alpha\beta$ and dq-coordinate frame, adopting a multivariable approach. Given the lack of functional controllability in the plant, an analysis of the frequency-dependent relative gain array is conducted to assist in determining the most suitable variables to be controlled within a specific frequency range. This analysis plays a critical role in selecting appropriate low- and high-frequency controllers for the system.