Grid connection design and control of LCL+Trap filter based two-level VSC for wave power plant applications

Abstract

This paper presents a filter design methodology and control design strategy for LCL+Trap filters deployed in large scale wave power plants. This filter topology appears as an alternative for the widely used LCL filters, since effective harmonic mitigation can be achieved while reducing the overall passive filter components size. As a result, the use of LCL+Trap filters for two-level power converters arise as a suitable power processing solution to match the requirements of large scale wave energy applications, since such well-known power converter technology is very robust, reliable and very cost effective. The designed LCL+Trap filter is validated through simulation by performing a comparative analysis between LCL and LCL+Trap filters, and finally, the control of the converter is introduced with the purpose of validating the grid connection compliance of the entire power processing system.