Control method for grid-connected converters in systems with non-ideal supply voltage

When employed in systems with higher frequency variability and potentially non-ideal supply voltage such as micro-grids, the synchronization method used in converter control systems must be considered. A method is presented here that achieves synchronization implicitly through the use of a Discrete Fourier Transform in combination with the computation of an effective admittance. Thus, the method provides near immunity to high frequency variability. Furthermore, the method is suitable for systems with non-ideal supply voltage including heavy voltage asymmetry.