Γ-Source Magnetic Integrated Filter for Single-Phase Grid Tied Voltage Source Converters

This article proposes two magnetic integrated filters, called Gamma-source and Flipped-Gamma-source with the advantage of better magnetic circuit utilization. Therefore, the number of required magnetic cores and the total size of inductive elements are reduced compared to the other high-order filters, such as the LCL and the LLCL. Also, the total windings copper weight as well as the windings currents and losses are lower. It will be shown that the required air gap for the magnetic core is very short, so the adverse effects of the electro-magnetic interference and the fringing flux are also prevented. Thus, the proposed filters require a small and simple magnetic element, which also works at a lower temperature. Moreover, the proposed filters offer a robust stability and a high filtering performance against a wide range of parameter mismatches. Based on the theoretical analysis and the comparative experimental tests on a grid tied converter, the advantages of the proposed filters are confirmed.