LCL Filters for a grid emulator application - Comparative study of active damping techniques

This paper focuses on the implementation of LCL filter active damping in the control of an inverter for a three-phase grid emulator application. The studies about LCL damping in the literature focus on the case of an inverter injecting current into the grid while a grid emulator application is rather about establishing correct voltage waveforms and emulating the grid for any kind of load connected to it, which brings a different perspective. After having analyzed the stability of the LCL filter taking into account possible load variations, three damping methods are compared and assessed with respect to those concerns.